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Suppose that you have an abstract for a scientific paper: we study the dynamics of spin-1 atoms in a periodic optical - lattice potential and an external magnetic field in a quantum quench scenario where we start from a superfluid ground state in a shallow lattice potential and suddenly raise the lattice depth . the time evolution of the non - equilibrium state , thus created , shows collective collapse - and - revival oscillations of matter - wave coherence as well as oscillations in the spin populations . we show that the complex pattern of these two types of oscillations reveals details about the superfluid and magnetic properties of the initial many - body ground state . furthermore , we show that the strengths of the spin - dependent and spin - independent atom - atom interactions can be deduced from the observations . the hamiltonian that describes the physics of the final deep lattice not only contains two - body interactions but also effective multi - body interactions , which arise due to virtual excitations to higher bands . we derive these effective spin - dependent three - body interaction parameters for spin-1 atoms and describe how spin - mixing is affected . spinor atoms are unique in the sense that multi - body interactions are directly evident in the _ in - situ _ number densities in addition to the momentum distributions . we treat both antiferromagnetic ( e.g. @xmath0na atoms ) and ferromagnetic ( e.g. @xmath1rb and @xmath2k ) condensates . . And you have already written the first three sentences of the full article: quantum degenerate ultracold atoms with spin - degree of freedom exhibit both magnetic order and superfluidity , offering a rich system in which to explore quantum coherence , long - range order , magnetism and symmetry breaking . many aspects of spinor atoms in a trap have been investigated with spin @xmath3 atoms , such as @xmath0na and @xmath1rb @xcite . spin-2 @xcite and spin-3 @xcite spinor gases have been studied to a lesser extent .. Please generate the next two sentences of the article

spinor condensates are described by a vector order parameter @xcite . the distinctive feature is its spin - dependent interaction which organizes spins giving rise to ferromagnetic and antiferromagnetic ( polar ) order .

Suppose that you have an abstract for a scientific paper: this paper presents a memory efficient , high throughput parallel lifting based running three dimensional discrete wavelet transform ( 3-d dwt ) architecture . 3-d dwt is constructed by combining the two spatial and four temporal processors . spatial processor ( sp ) apply the two dimensional dwt on a frame , using lifting based 9/7 filter bank through the row rocessor ( rp ) in row direction and then apply in the colum direction through column processor ( cp ) . to reduce the temporal memory and the latency , the temporal processor ( tp ) has been designed with lifting based 1-d haar wavelet filter . the proposed architecture replaced the multiplications by pipeline shift - add operations to reduce the cpd . two spatial processors works simultaneously on two adjacent frames and provide 2-d dwt coefficients as inputs to the temporal processors . tps apply the one dimensional dwt in temporal direction and provide eight 3-d dwt coefficients per clock ( throughput ) . higher throughput reduces the computing cycles per frame and enable the lower power consumption . implementation results shows that the proposed architecture has the advantage in reduced memory , low power consumption , low latency , and high throughput over the existing designs . the rtl of the proposed architecture is described using verilog and synthesized using 90-nm technology cmos standard cell library and results show that it consumes 43.42 mw power and occupies an area equivalent to 231.45 k equivalent gate at frequency of 200 mhz . the proposed architecture has also been synthesised for the xilinx zynq 7020 series field programmable gate array ( fpga ) . index terms : discrete wavelet transform , 3-d dwt , lifting based dwt , vlsi architecture , flipping structure , strip - based scanning . . And you have already written the first three sentences of the full article: video compression is a major requirement in many of the recent applications like medical imaging , studio applications and broadcasting applications . compression ratio of the encoder completely depends on the underlying compression algorithms . the goal of compression techniques is to reduce the immense amount of visual information to a manageable size so that it can be efficiently stored , transmitted , and displayed .. Please generate the next two sentences of the article

3-d dwt based compressing system enables the compression in spatial as well as temporal direction which is more suitable for video compression . moreover , wavelet based compression provide the scalability with the levels of decomposition . due to continuous increase in size of the video frames ( hd to uhd ) , video processing through software coding tools

Suppose that you have an abstract for a scientific paper: the effect of rotation on the cooling of neutron stars is investigated . the thermal evolution equations are solved in two dimensions with full account of general relativistic effects . it is found that rotation is particularly important in the early epoch when the neutron star s interior is not yet isothermal . the polar surface temperature is up to 63% higher than the equatorial temperature . this temperature difference might be observable if the thermal radiation of a young , rapidly rotating neutron star is detected . in the intermediate epoch ( @xmath0 yr ) , when the interior becomes isothermal , the polar temperature is still up to 31% higher than the equatorial temperature . afterwards photon surface radiation dominates the cooling , and the surface becomes isothermal on a timescale of @xmath1 yr . furthermore , the transition between the early and the intermediate epochs is delayed by several hundred years . an additional effect of rotation is the reduction of the neutrino luminosity due to the reduction of the central density with respect to the non - rotating case . . And you have already written the first three sentences of the full article: in the past three decades the cooling history of neutron stars was investigated by several authors ( e.g. @xcite ) . recent numerical simulations account for non - isothermal interior , as well as for general relativistic effects . nevertheless , as far as we know , all investigations assumed spherical symmetry of geometry and temperature distribution . as it was pointed out by miralles et al . ( 1993 ) , the effect of rapid rotation on the cooling of neutron stars can be as important as general relativistic effects , whereas the effect of slow rotation should be negligible .. Please generate the next two sentences of the article

although the assumption of slow rotation holds for most of the known pulsars , there exist a couple of millisecond pulsars ( @xcite ) , for which rotation should yield a rather different cooling behaviour . these millisecond pulsars are generally located in binary systems .

Suppose that you have an abstract for a scientific paper: we investigate the tev - scale stringy signals of the four - fermion scattering at the electron - positron collider with the center of mass energy @xmath0 gev . the nature of the stringy couplings leads to distinguishable asymmetries comparing to the other new physics models . specifically , the stringy states in the four - fermion scattering at the leading - order corrections are of spin-1 and 2 with the chiral couplings inherited from the gauge bosons identified as the zeroth - mode string states . the angular left - right , forward - backward , center - edge asymmetries and the corresponding polarized - beam asymmetries are investigated . the low - energy stringy corrections are compared to the ones induced by the kaluza - klein ( kk ) gravitons . the angular left - right asymmetry of the scattering with the final states of @xmath1 and @xmath2-type quarks , namely @xmath3 and @xmath4 , shows significant deviations from the standard model values . the center - edge and forward - backward asymmetries for all final - states fermions also show significant deviations from the corresponding standard model values . the differences between the signatures induced by the stringy corrections and the kk gravitons are appreciable in both angular left - right and forward - backward asymmetries . @xmath5 0.4 cm . And you have already written the first three sentences of the full article: there is a number of new physics ( np ) models beyond the standard model ( sm ) of particle physics . motivated by the hierachy and/or the fine - tuning problem in the sm , most np models propose new states with tev - scale masses . a few examples are the susy models , models with extra gauge bosons ( @xmath6 models ) , and the models with extra dimensions .. Please generate the next two sentences of the article

when the masses of the np states are heavier than the center of mass ( cm ) energy of the collider , the effects of the np can be measured indirectly in terms of the deviations of the sm observables such as the total cross section and various asymmetries . the deviations from the sm in the scattering processes are determined by the mass , spin , and coupling strength of the new states being exchanged by the initial state particles .

Suppose that you have an abstract for a scientific paper: we perform some numerical study of the secular triaxial instability of rigidly rotating homogeneous fluid bodies in general relativity . in the newtonian limit , this instability arises at the bifurcation point between the maclaurin and jacobi sequences . it can be driven in astrophysical systems by viscous dissipation . we locate the onset of instability along several constant baryon mass sequences of uniformly rotating axisymmetric bodies for compaction parameter @xmath0 . we find that general relativity weakens the jacobi like bar mode instability , but the stabilizing effect is not very strong . according to our analysis the critical value of the ratio of the kinetic energy to the absolute value of the gravitational potential energy @xmath1 for compaction parameter as high as @xmath2 is only @xmath3 higher than the newtonian value . the critical value of the eccentricity depends very weakly on the degree of relativity and for @xmath4 is only @xmath5 larger than the newtonian value at the onset for the secular bar mode instability . we compare our numerical results with recent analytical investigations based on the post - newtonian expansion . . And you have already written the first three sentences of the full article: in newtonian theory a self - gravitating incompressible fluid body rotating at a moderate velocity around a fixed axis with respect to some inertial frame takes the shape of a maclaurin ellipsoid , which is axisymmetric with respect to the rotation axis . for a higher rotation rate , namely when the ratio of kinetic to gravitational potential energy @xmath6 is larger than @xmath7 , another figure of equilibrium exists : that of a jacobi ellipsoid , which is triaxial and rotates around its smallest axis @xcite . actually the jacobi ellipsoid is a preferred figure of equilibrium , since at fixed mass and angular momentum , it has a lower total energy @xmath8 than a maclaurin ellipsoid , due to its greater moment of inertia @xmath9 with respect to the rotation axis . indeed , at fixed angular momentum @xmath10 , the kinetic energy @xmath11 is a decreasing function of @xmath9 , and for large values of @xmath10 , this decrease overcomes the effect of the gravitational potential energy @xmath12 , which increases with @xmath9 .. Please generate the next two sentences of the article

therefore , provided some mechanism acts for dissipating energy while preserving angular momentum ( for instance viscosity ) , a maclaurin ellipsoid with @xmath13 will break its axial symmetry and migrate toward a jacobi ellipsoid @xcite . this is the secular `` bar mode '' instability of rigidly rapidly rotating bodies .

Suppose that you have an abstract for a scientific paper: we show that the right - handed ( rh ) sneutrino in the nmssm can account for the observed excess in the fermi - lat spectrum of gamma - rays from the galactic centre , while fulfilling all the current experimental constraints from the lhc as well as from direct and indirect dark matter searches . we have explored the parameter space of this scenario , computed the gamma - ray spectrum for each phenomenologically viable solution and then performed a @xmath0 fit to the excess . unlike previous studies based on model - independent interpretations , we have taken into account the full annihilation spectrum , without assuming pure annihilation channels . furthermore , we have incorporated limits from direct detection experiments , lhc bounds and also the constraints from fermi - lat on dwarf spheroidal galaxies ( dsphs ) and gamma - ray spectral lines . in addition , we have estimated the effect of the most recent fermi - lat reprocessed data ( pass 8) . in general , we obtain good fits to the gce when the rh sneutrino annihilates mainly into pairs of light singlet - like scalar or pseudoscalar higgs bosons that subsequently decay in flight , producing four - body final states and spectral features that improve the goodness of the fit at large energies . the best fit ( @xmath1 ) corresponds to a rh sneutrino with a mass of 64 gev which annihilates preferentially into a pair of light singlet - like pseudoscalar higgs bosons ( with masses of order 60 gev ) . besides , we have analysed other channels that also provide good fits to the excess . finally , we discuss the implications for direct and indirect detection searches paying special attention to the possible appearance of gamma - ray spectral features in near future fermi - lat analyses , as well as deviations from the sm - like higgs properties at the lhc . remarkably , many of the scenarios that fit the gce can also be probed by these other complementary techniques . . And you have already written the first three sentences of the full article: a large number of cosmological and astrophysical observations have evidenced that 85% of the matter content of the universe is in the form of dark matter ( dm ) . a generic weakly interacting massive particle ( wimp ) is a well - motivated candidate for this new kind of matter , since its thermal production in the early universe would match the observed dm abundance . in addition , wimps can be easily accommodated in theories beyond the standard model , such as supersymmetry ( susy ) .. Please generate the next two sentences of the article

wimps can be searched for indirectly , through the particles produced when they annihilate in the dm halo ( photons , neutrinos and antiparticles ) . among the different annihilation products , gamma - rays provide an appealing detection possibility because the signal can be traced back to the source .

Suppose that you have an abstract for a scientific paper: in this paper we consider the process of `` subthreshold '' electron - positron pairs creation in the region of laser conversion . the total number of positrons and their distribution are obtained . this phenomena is offered for use as a good test to examine nonlinear effects of quantum electrodynamics on tesla . . And you have already written the first three sentences of the full article: since the end of the eighties and by this time works on designing and development of physical programs for @xmath0 and @xmath1 - colliders are under development in different countries . now there are projects on their creation in usa [ 1 ] , germany [ 2 ] , japan [ 3 ] . physical programs for these colliders created as a result of long - term cooperation of the representatives of many high - energy physics centres are stated in `` conceptual design reports '' [ 1 - 3 ] . in these projects electron - photon and photon - photon beams. Please generate the next two sentences of the article

are supposed to be obtained on the basis of linear accelerators with @xmath2 beams . one of the best methods of obtaining intensive @xmath3 beams is the use of the compton backscattering of laser light on an electron beam of the linear collider .

Suppose that you have an abstract for a scientific paper: richardson s theory of turbulent particle pair diffusion [ richardson , l. f. proc . roy . soc . lond . a 100 , 709737 , 1926 ] , based upon observational data , is equivalent to a locality hypothesis in which the turbulent pair diffusivity @xmath0 scales with the pair separation @xmath1 with a 4/3-power law , @xmath2 . here , a reappraisal of the 1926 dataset reveals that one of the data - points is from a molecular diffusion context ; the remaining data from geophysical turbulence display an unequivocal non - local scaling , @xmath3 . consequently , the foundations of pair diffusion theory have been re - examined , leading to a new theory based upon the principle that both local and non - local diffusional processes govern pair diffusion in homogeneous turbulence . through a novel mathematical approach the theory is developed in the context of generalised power law energy spectra , @xmath4 for @xmath5 , over extended inertial subranges . the theory predicts the scaling , @xmath6 , with @xmath7 intermediate between the purely local and the purely non - local scalings , i.e. @xmath8 . a lagrangian diffusion model , kinematic simulations [ kraichnan , r. h. , phys . fluids 13 , 22 - 31 , 1970 ; fung et al . , j. fluid mech . 236 , 281 - 318 , 1992 ] , is used to examine the predictions of the new theory all of which are confirmed . the simulations produce the scalings , @xmath9 to @xmath10 , in the accepted range of intermittent turbulence spectra , @xmath11 to @xmath12 , in close agreement with the revised 1926 dataset . turbulence , pair diffusion , richardson , non - local , mathematical foundations , simulation . And you have already written the first three sentences of the full article: turbulent transport and mixing play an essential role in many natural and industrial processes @xcite , in cloud formation @xcite , in chemical reactors and combustion systems @xcite , and atmospheric and oceanographic turbulence determines the spread of pollutants and biological agents in geophysical flows @xcite , @xcite , @xcite , @xcite . concentration fluctuations are often of great importance in such systems and this is related to the separation of nearby fluid particles ; turbulent pair diffusion therefore plays a critical role in such systems . the idea of locality has been fundamental to the theory of turbulent particle pair diffusion since richardson s pioneering paper , @xcite , which established turbulent pair diffusion as an important scientific discipline and laid the foundations for a theory of how ensembles of pairs of fluid particles ( tracers ) initially close together move apart due to the effects of atmospheric winds and turbulence .. Please generate the next two sentences of the article

richardson argued that as particle pairs separate the rate at which they move apart is affected mostly by eddies of the same scale as the separation distance itself this is the basis of the locality hypothesis . richardson was also motivated by a desire to bring molecular and turbulent pair diffusional processes into a unified picture through the use of a single non - fickian diffusion equation with scale dependent diffusivity , @xmath13 , where @xmath14 is the pair separation variable .

Suppose that you have an abstract for a scientific paper: we report the coexistence and properties of stable compact localized states ( clss ) and discrete solitons ( dss ) for nonlinear spinor waves on a flatband network with spin - orbit coupling ( soc ) . the system can be implemented by means of a binary bose - einstein condensate loaded in the corresponding optical lattice . in the linear limit , the soc opens a minigap between flat and dispersive bands in the system s bandgap structure , and preserves the existence of clss at the flatband frequency , simultaneously lowering their symmetry . adding onsite cubic nonlinearity , the clss persist and remain available in an exact analytical form , with frequencies which are smoothly tuned into the minigap . inside of the minigap , the cls and ds families are stable in narrow areas adjacent to the fb . deep inside the semi - infinite gap , both the clss and dss are stable too . . And you have already written the first three sentences of the full article: wave dynamics can be tailored by symmetries and topologies imprinted by dint of underlying periodic potentials . in turn , the symmetries and topologies of the periodic potentials can be probed by excitations in the system into which the potential is embedded . in particular , flatband ( fb ) lattices , existing due to specific local symmetries , provide the framework supporting completely dispersionless bands in the system s spectrum @xcite . fb lattices have been realized in photonic waveguide arrays @xcite , exciton - polariton condensates @xcite , and atomic bose - einstein condensates ( becs ) @xcite . fb lattices are characterized by the existence of compact localized states ( clss ) , which , being fb eigenstates , have nonzero amplitudes only on a finite number of sites @xcite .. Please generate the next two sentences of the article

the clss are natural states for the consideration of their perturbed evolution . they feature different local symmetry and topology properties , and can be classified according to the number @xmath0 of unit cells which they occupy @xcite .

Suppose that you have an abstract for a scientific paper: we study the dynamics caused by transport of transverse magnetization in one dimensional transverse ising chain at zero temperature . we observe that a class of initial states in fermionic momentum - space produce spatial variation in transverse magnetization . starting from such a state , we obtain the transverse magnetization analytically and then observe its dynamics in presence of a homogeneous constant field @xmath0 . in contradiction with general expectation , whatever be the strength of the field , the magnetization of the system does not become homogeneous even after infinite time . in each site , the dynamics is associated with oscillations having two different timescales . the envelope of the larger timescale oscillation decays algebraically having an exponent which is universal for the entire class of such initial states . signature of quantum criticality is also embedded in the dynamics in two aspects : behavioral change shown by the frequency of large timescale oscillation at any site and the corresponding magnetization at infinity when they cross the quantum critical point . . And you have already written the first three sentences of the full article: quantum many - body system out of equilibrium has been subjected to upsurging interest in recent times . extensive studies have been done over decades giving rise to many new findings in this field ( see @xcite for a review ) . lots of questions still remain unresolved too . from the results obtained so far , it is impossible to draw a generic picture of the dynamics out of equilibrium .. Please generate the next two sentences of the article

emergence of current of a physical quantity generally renders a system to a nonequilibrium one . transport of that quantity due to presence of current thereby gets attention as an important aspect of nonequilibrium dynamics .

Suppose that you have an abstract for a scientific paper: we propose and analyze a multi - functional setup consisting of high finesse optical cavities , beam splitters , and phase shifters . the basic scheme projects arbitrary photonic two - mode input states onto the subspace spanned by the product of fock states @xmath0 with @xmath1 . this protocol does not only provide the possibility to conditionally generate highly entangled photon number states as resource for quantum information protocols but also allows one to test and hence purify this type of quantum states in a communication scenario , which is of great practical importance . the scheme is especially attractive as a generalization to many modes allows for distribution and purification of entanglement in networks . in an alternative working mode , the setup allows of quantum non demolition number resolved photodetection in the optical domain . . And you have already written the first three sentences of the full article: light plays an essential role in quantum communication and is indispensable in most practical applications , for example quantum cryptography . photons are attractive carriers of quantum information because the interactions of light with the surroundings are normally weak , but for the same reason it is generally difficult to prepare , manipulate , and measure quantum states of light in a nondestructive way . repeated interactions provide a method to increase the effective coupling strength between light and matter , and the backreflection of light in a cavity thus constitutes an interesting tool , in particular , because experiments are currently moving into the strong coupling regime @xcite , where coherent dynamics takes place on a faster time scale than dissipative dynamics . in this paper. Please generate the next two sentences of the article

we propose a versatile setup consisting of an array of cavities and passive optical elements ( beam splitters and phase shifters ) , which allows for quantum state engineering , quantum state purification , and non - destructive number resolving photon detection . the setup builds on two basic ingredients : the hong - ou - mandel interference effect @xcite generalized to input pulses containing an arbitrary number of photons and the possibility of projection onto the subspace of even or the subspace of odd photon - number states by use of cavity quantum electrodynamics in the strong coupling regime .

Suppose that you have an abstract for a scientific paper: we investigate zero sound in @xmath0-dimensional effective holographic theories , whose action is given by einstein - maxwell - dilaton terms . the bulk spacetimes include both zero temperature backgrounds with anisotropic scaling symmetry and their near - extremal counterparts obtained in 1006.2124 [ hep - th ] , while the massless charge carriers are described by probe d - branes . we discuss thermodynamics of the probe d - branes analytically . in particular , we clarify the conditions under which the specific heat is linear in the temperature , which is a characteristic feature of fermi liquids . we also compute the retarded green s functions in the limit of low frequency and low momentum and find quasi - particle excitations in certain regime of the parameters . the retarded green s functions are plotted at specific values of parameters in @xmath1 , where the specific heat is linear in the temperature and the quasi - particle excitation exists . we also calculate the ac conductivity in @xmath0-dimensions as a by - product . cquest-2010 - 0395 * zero sound in effective holographic theories * bum - hoon lee@xmath2 , da - wei pang@xmath3 and chanyong park@xmath3 + _ seoul 121 - 742 , korea + _ _ @xmath4 center for quantum spacetime , sogang university _ + _ seoul 121 - 742 , korea + _ bhl@sogang.ac.kr , pangdw@sogang.ac.kr , cyong21@sogang.ac.kr . And you have already written the first three sentences of the full article: the ads / cft correspondence @xcite has revealed the deep relations between gauge theories and string theories and has provided powerful tools for understanding the dynamics of strongly coupled field theories in the dual gravity side . in recent years , this paradigm has been applied to investigate the properties of certain condensed matter systems @xcite . the correspondence between gravity theories and condensed matter physics(sometimes is also named as ads / cmt correspondence ) has shed light on studying physics in the real world in the context of holography . it is well known that in realistic condensed matter systems , the presence of a finite density of charge carriers is of great importance . according to the ads / cft correspondence , the dual bulk gravitational background should be charged black holes in asymptotically ads spacetimes .. Please generate the next two sentences of the article

the simplest example of such charged ads black holes is reissner - nordstrm - ads(rn - ads ) black hole , which has proven to be an efficient laboratory for studying the ads / cmt correspondence . for instance , investigations of the fermionic two - point functions in this background indicated the existence of fermionic quasi - particles with non - fermi liquid behavior @xcite , while the @xmath5 symmetry of the extremal rn - ads black hole is crucial to the emergent scaling symmetry at zero temperature @xcite .

Suppose that you have an abstract for a scientific paper: we review recent progress of understanding and resolving instabilities driven by mismatch between the fermi surfaces of the pairing quarks in 2-flavor color superconductor . with the increase of mismatch , the 2sc phase exhibits chromomagnetic instability as well as color neutral baryon current instability . we describe the 2sc phase in the nonlinear realization framework , and show that each instability indicates the spontaneous generation of the corresponding pseudo nambu - golstone current . the nambu - goldstone currents generation state covers the gluon phase as well as the one - plane wave loff state . we further point out that , when charge neutrality condition is required , there exists a narrow unstable loff ( us - loff ) window , where not only off - diagonal gluons but the diagonal 8-th gluon can not avoid the magnetic instability . in this us - loff window , the diagonal magnetic instability can not be cured by off - diagonal gluon condensate in the color superconducting phase . . And you have already written the first three sentences of the full article: studying qcd at finite baryon density is the traditional subject of nuclear physics . the behaviour of qcd at finite baryon density and low temperature is central for astrophysics to understand the structure of compact stars , and conditions near the core of collapsing stars ( supernovae , hypernovae ) . it is known that sufficiently cold and dense baryonic matter is in the color superconducting phase .. Please generate the next two sentences of the article

this was proposed several decades ago by frautschi @xcite and barrois @xcite by noticing that one - gluon exchange between two quarks is attractive in the color antitriplet channel . from bcs theory @xcite , we know that if there is a weak attractive interaction in a cold fermi sea , the system is unstable with respect to the formation of particle - particle cooper - pair condensate in the momentum space . studies on color superconducting phase in 1980 s can be found in ref .

Suppose that you have an abstract for a scientific paper: the knowledge of quantum phase flow induced under the weyl s association rule by the evolution of heisenberg operators of canonical coordinates and momenta allows to find the evolution of symbols of generic heisenberg operators . the quantum phase flow curves obey the quantum hamilton s equations and play the role of characteristics . at any fixed level of accuracy of semiclassical expansion , quantum characteristics can be constructed by solving a coupled system of first - order ordinary differential equations for quantum trajectories and generalized jacobi fields . classical and quantum constraint systems are discussed . the phase - space analytic geometry based on the star - product operation can hardly be visualized . the statement `` quantum trajectory belongs to a constraint submanifold '' can be changed e.g. to the opposite by a unitary transformation . some of relations among quantum objects in phase space are , however , left invariant by unitary transformations and support partly geometric relations of belonging and intersection . quantum phase flow satisfies the star - composition law and preserves hamiltonian and constraint star - functions . . And you have already written the first three sentences of the full article: the star - product operation introduced by groenewold for phase - space functions @xcite permits formulation of quantum mechanics in phase space . it uses the weyl s association rule @xcite to establish one - to - one correspondence between phase - space functions and operators in the hilbert space . the wigner function @xcite appears as the weyl s symbol of the density matrix .. Please generate the next two sentences of the article

the skew - symmetric part of the star - product , known as the moyal bracket @xcite , governs the evolution of symbols of heisenberg operators . refined formulation of the weyl s association rule is proposed by stratonovich @xcite .

Suppose that you have an abstract for a scientific paper: in this paper , we consider a multi - cell multi - user miso broadcast channel . the system operates according to the opportunistic beamforming framework in a multi - cell environment with variable number of transmit beams ( may alternatively be referred as the transmission rank ) at each base station . the maximum number of co - scheduled users in a cell is equal to its transmission rank , thus increasing it will have the effect of increasing the multiplexing gain . however , this will simultaneously increase the amount of interference in the network , which will decrease the rate of communication . this paper focuses on optimally setting the transmission rank at each base station such that a set of quality of service ( qos ) constraints , that will ensure a guaranteed minimum rate per beam at each base station , is not violated . expressions representing the achievable region of transmission ranks are obtained considering different network settings . the achievable transmission rank region consists of all achievable transmission rank tuples that satisfy the qos constraints . numerical results are also presented to provide further insights on the feasibility problem . . And you have already written the first three sentences of the full article: opportunistic beamforming ( obf ) is a well known adaptive signaling scheme that has received a great deal of attention in the literature as it attains the sum - rate capacity with full channel state information ( csi ) to a first order for large numbers of mobile users in the network , while operating on partial csi feedback from the users . in this paper , we consider a cellular network which operates according to the obf framework in a multi - cell environment with variable number of transmit beams at each bs . the number of transmit beams is also referred to as the transmission rank ( tr ) in the paper , and we focus on optimally setting the transmission rank at each bs in the network .. Please generate the next two sentences of the article

the earliest work of obf appeared in the landmark paper @xcite , where the authors have introduced a single - beam obf scheme for the single - cell multiple - input single - output ( miso ) broadcast channel . the concept was extended to @xmath0 random orthogonal beams in @xcite , where @xmath0 is the number of transmit antennas .

Suppose that you have an abstract for a scientific paper: sciboone , located in the booster neutrino beam at fermilab , collected data from june 2007 to august 2008 to accurately measure muon neutrino and anti - neutrino cross sections on carbon below 1 gev neutrino energy . sciboone is studying charged current interactions . among them , neutral pion production interactions will be the focus of this poster . the experimental signature of neutrino - induced neutral pion production is constituted by two electromagnetic cascades initiated by the conversion of the @xmath0 decay photons , with an additional muon in the final state for cc processes . in this poster , i will present how we reconstruct and select charged - current muon neutrino interactions producing @xmath0 s in sciboone address = ific ( u. valencia / csic ) . And you have already written the first three sentences of the full article: sciboone @xcite is a muon neutrino scattering experiment located at the boone neutrino beam at fermilab . the 0.8 gev mean energy neutrino beam is produced with a 8 gev proton beam . protons hit a beryllium target producing charged pions that are selected and focused using a magnetic horn .. Please generate the next two sentences of the article

the ability to switch the horn polarity allows to select @xmath1 to produce neutrino beam or @xmath2 to produce anti - neutrino beam . only neutrino beam is currently used in this analysis .

Suppose that you have an abstract for a scientific paper: we show how to orient moduli spaces of holomorphic disks with boundary on an exact lagrangian immersion of a spin manifold into complex @xmath0-space in a coherent manner . this allows us to lift the coefficients of the contact homology of legendrian spin submanifolds of standard contact @xmath1-space from @xmath2 to @xmath3 we demonstrate how the @xmath4-lift provides a more refined invariant of legendrian isotopy . we also apply contact homology to produce lower bounds on double points of certain exact lagrangian immersions into @xmath5 and again including orientations strengthens the results . more precisely , we prove that the number of double points of an exact lagrangian immersion of a closed manifold @xmath6 whose associated legendrian embedding has good dga is at least half of the dimension of the homology of @xmath6 with coefficients in an arbitrary field if @xmath6 is spin and in @xmath2 otherwise . . And you have already written the first three sentences of the full article: legendrian contact homology has been an effective tool in studying legendrian submanifolds in @xmath7 in @xmath8 , chekanov @xcite and eliashberg and hofer ( unpublished but see @xcite ) used contact homology to show that legendrian knots are not determined up to legendrian isotopy by the so - called classical invariants ( topological isotopy class , thurston - bennequin number , and maslov class ) . subsequently , contact homology has been used to greatly illuminate the nature of legendrian knots in @xmath9 the contact homology of legendrian submanifolds in @xmath10 ( for @xmath11 ) was given a rigorous foundation in @xcite and its efficacy was demonstrated in @xcite . very roughly speaking contact homology is the homology of a differential graded algebra ( dga ) associated to a legendrian submanifold @xmath12 . the algebra is generated by double points in the ( lagrangian ) projection of @xmath13 into @xmath5 and the differential counts rigid holomorphic disk with corners at these double points and boundary on the projected legendrian submanifold . in the initial definition of contact homology. Please generate the next two sentences of the article

the disks were counted modulo 2 since in that version of the theory orientations and orientability of spaces of holomorphic disks need not be considered . a @xmath4-lift of contact homology of legendrian knots in @xmath8 have been introduced in a purely combinatorial fashion in @xcite .

Suppose that you have an abstract for a scientific paper: the astri project aims to develop , in the framework of the cherenkov telescope array , an end - to - end prototype of the small - size telescope , devoted to the investigation of the energy range @xmath0 1100 tev . the proposed design is characterized by two challenging but innovative technological solutions which will be adopted for the first time on a cherenkov telescope : a dual - mirror schwarzschild couder configuration and a modular , light and compact camera based on silicon photo - multipliers . here we describe the prototype design , the expected performance and the possibility to realize a mini array composed by a few such telescopes , which shall be placed at the final cta southern site . . And you have already written the first three sentences of the full article: the cherenkov telescope array ( cta , acharya et al . 2013@xcite ) is the project of a new array of several imaging atmospheric cherenkov telescopes ( iacts ) for very high - energy ( vhe ) astronomy . the array shall be composed by three different types of telescopes , in order to maximize the performance in three different energy ranges : the large size telescope ( lst ) for the low energy range ( e @xmath1 20 gev 1 tev ) , the medium size telescope ( mst ) for the core energy range ( e @xmath1 0.110 tev ) , and the small size telescope ( sst ) for the high energy range ( e @xmath2 1 tev ) . the astri project ( ` astrofisica con specchi a tecnologia replicante italiana ' ) is included in this framework : it is a ` flagship project ' of the italian ministry of education , university and research , which , under the leadership of the italian national institute of astrophysics ( inaf ) , aims to realize and test an end - to - end prototype of the sst .. Please generate the next two sentences of the article

the astri sst-2 m prototype is characterized by two special features which will be adopted for the first time on a cherenkov telescope ( pareschi et al . 2013@xcite ) : a dual - mirror schwarzschild

Suppose that you have an abstract for a scientific paper: we propose experimental verification and theoretical explanation of magnetic anomalies in the complex fe - contained double perovskite multiferroics like pbfe@xmath0nb@xmath0o@xmath1 . the theoretical part is based on our model of coexistence of long - range magnetic order and spin glass in the above substances . in our model , the exchange interaction is anisotropic , coupling antiferromagnetically @xmath2 spin components of fe@xmath3 ions . at the same time , the @xmath4 components are coupled by much weaker exchange interaction of ferromagnetic sign . in the system with spatial disorder ( half of corresponding lattice cites are occupied by spinless nb@xmath5 ions ) such frustrating interaction results in the fact that antiferromagnetic order is formed by @xmath2 projection of the spins , while their @xmath4 components contribute to spin glass behaviour . our theoretical findings are supported by the experimental evidence of coexistence of antiferromagnetic and spin glass phases in chemically disordered fe - contained double perovskite multiferroics . . And you have already written the first three sentences of the full article: in the context of novel materials with unusual physical properties , the researchers are interested in the fe - based double perovskite multiferroics with the general formula pbfe@xmath0m@xmath0o@xmath1 ( m = nb , ta , sb ) and their solid solutions with substitution of a or b type ions in the abo@xmath1 perovskite structure , see , e.g. @xcite and references therein . recent studies @xcite of these substances reveal a lot of interesting properties like large magnetoelectric coupling and high dielectric permittivity . it had been shown in the above papers that these properties occur in substantial range of temperatures and chemical compositions , revealing the existence of ferroelectric ( fe ) , antiferromagnetic ( afm ) and spin glass ( sg ) phases on the corresponding phase diagrams . in the above compounds ,. Please generate the next two sentences of the article

fe@xmath3 and m@xmath5 cation positions may be ordered or disordered within the simple cubic b sublattice of the perovskite abo@xmath1 structure . the degree of chemical ordering depends on the relative strengths of electrostatic and elastic energies and on the ionic radii of these cations in particular .

Suppose that you have an abstract for a scientific paper: we show that it is possible to reach one of the ultimate goals of organic electronics : producing organic field - effect transistors with trap densities as low as in the bulk of single crystals . we studied the spectral density of localized states in the band gap ( trap dos ) of small molecule organic semiconductors as derived from electrical characteristics of organic field - effect transistors or from space - charge - limited - current measurements . this was done by comparing data from a large number of samples including thin - film transistors ( tft s ) , single crystal field - effect transistors ( sc - fet s ) and bulk samples . the compilation of all data strongly suggests that structural defects associated with grain boundaries are the main cause of `` fast '' hole traps in tft s made with vacuum - evaporated pentacene . for high - performance transistors made with small molecule semiconductors such as rubrene it is essential to reduce the dipolar disorder caused by water adsorbed on the gate dielectric surface . in samples with very low trap densities , we sometimes observe a steep increase of the trap dos very close ( @xmath0ev ) to the mobility edge with a characteristic slope of @xmath1mev . it is discussed to what degree band broadening due to the thermal fluctuation of the intermolecular transfer integral is reflected in this steep increase of the trap dos . moreover , we show that the trap dos in tft s with small molecule semiconductors is very similar to the trap dos in hydrogenated amorphous silicon even though polycrystalline films of small molecules with van der waals - type interaction on the one hand are compared with covalently bound amorphous silicon on the other hand . although important conclusions can already be drawn from the existing data , more experiments are needed to complete the understanding of the trap dos near the band edge in small molecule organic semiconductors . . And you have already written the first three sentences of the full article: organic semiconductors are envisioned to revolutionize display and lighting technology . the remaining engineering - related challenges are being tackled and the first products are commercially available already . to guarantee a sustainable market entry , however , it is important to further deepen the understanding of organic semiconductors and organic semiconductor devices . electronic trap states in organic semiconductors severely affect the performance of such devices . for organic thin - film transistors ( tft s ) , for example , key device parameters such as the effective charge mobility , the threshold voltage , the subthreshold swing as well as the electrical and environmental stability are severely affected by trap states at the interface between the gate dielectric and the semiconductor .. Please generate the next two sentences of the article

trap states in organic semiconductors have been studied for several decades.@xcite although the first organic field - effect transistors emerged in the 1980 s , ( polymeric semiconductors : ref . , small molecule organic semiconductors : ref . ) it is only recently , that trap states in organic field - effect transistors are a subject of intense scientific investigation ( refs .

Suppose that you have an abstract for a scientific paper: we consider the problem of the statistics of the scattering matrix @xmath0 of a chaotic cavity ( quantum dot ) , which is coupled to the outside world by non - ideal leads containing @xmath1 scattering channels . the hamiltonian @xmath2 of the quantum dot is assumed to be an @xmath3 hermitian matrix with probability distribution @xmath4^{-(\beta m + 2 - \beta)/2}$ ] , where @xmath5 and @xmath6 are arbitrary coefficients and @xmath7 depending on the presence or absence of time - reversal and spin - rotation symmetry . we show that this `` lorentzian ensemble '' agrees with microscopic theory for an ensemble of disordered metal particles in the limit @xmath8 , and that for any @xmath9 it implies @xmath10 is the ensemble average of @xmath0 . this `` poisson kernel '' generalizes dyson s circular ensemble to the case @xmath11 and was previously obtained from a maximum entropy approach . the present work gives a microscopic justification for the case that the chaotic motion in the quantum dot is due to impurity scattering . . And you have already written the first three sentences of the full article: recent experiments@xcite on conductance fluctuations and weak - localization effects in quantum dots have stimulated theoretical work@xcite on phase - coherent conduction through cavities in which the classical electron motion can be regarded as chaotic . if the capacitance of the quantum dot is large enough , a description in terms of non - interacting electrons is appropriate ( otherwise the coulomb blockade becomes important@xcite ) . for an isolated chaotic cavity , it has been conjectured and confirmed by many examples that the statistics of the hamiltonian @xmath2 agrees with that of the gaussian ensemble of random - matrix theory.@xcite if the chaotic behavior is caused by impurity scattering , the agreement has been established by microscopic theory : both the gaussian ensemble and the ensemble of hamiltonians with randomly placed impurities are equivalent to a certain non - linear @xmath12-model.@xcite transport properties can be computed by coupling @xmath13 eigenstates of @xmath2 to @xmath1 scattering channels.@xcite since @xmath14 this construction introduces a great number of coupling parameters , whereas only a few independent parameters determine the statistics of the scattering matrix @xmath0 of the system.@xcite for transport properties at zero temperature and infinitesimal applied voltage , one only needs to know @xmath0 at the fermi energy @xmath15 , and an approach which starts directly from the ensemble of scattering matrices at a given energy is favorable .. Please generate the next two sentences of the article

following up on earlier work on chaotic scattering in billiards,@xcite two recent papers@xcite have studied the transport properties of a quantum dot under the assumption that @xmath0 is distributed according to dyson s circular ensemble.@xcite in refs . [ barangerm ] and [ jpb ] the coupling of the quantum dot to the external reservoirs was assumed to occur via ballistic point contacts ( or `` ideal leads '' ) .

Suppose that you have an abstract for a scientific paper: quantum mechanical entanglement can exist in noisy open quantum systems at high temperature . a simple mechanism , where system particles are randomly reset to some standard initial state , can counteract the deteriorating effect of decoherence , resulting in an entangled steady state far from thermodynamical equilibrium . we present models for both gas - type systems and for strongly coupled systems . we point out in which way the entanglement resulting from such a reset mechanism is different from the entanglement that one can find in thermal states . we develop master equations to describe the system and its interaction with an environment , study toy models with two particles ( qubits ) , where the master equation can often be solved analytically , and finally examine larger systems with possibly fluctuating particle numbers . we find that in gas - type systems , the reset mechanism can produce an entangled steady state for an arbitrary temperature of the environment , while this is not true in strongly coupled systems . but even then , the temperature range where one can find entangled steady states is typically much higher with the reset mechanism . . And you have already written the first three sentences of the full article: in quantum information theory entanglement between parts of a system has been identified as the key resource that can possibly make quantum information processing more powerful than classical information processing . entanglement can also be a resource for long - distance quantum communication or distributed quantum computation , and it is at the heart of some quantum communication protocols . but entanglement is fragile under the influence of environment induced decoherence .. Please generate the next two sentences of the article

all engineering hence thrives to better control and manipulate the quantum information stored in the system while keeping the detrimental effects of decoherence low . in nature , on the other hand , we mostly find less controllable systems , especially if the system size becomes macroscopic as in gases , fluids , solids or even biological systems .

Suppose that you have an abstract for a scientific paper: for two - dimensional many - particle systems first - order , second - order , single step continuous , as well as two - step continuous ( kthny - like ) melting transitions have been found in previous studies . recent computer simulations , using particle numbers in the @xmath0 range , as well as a few experimental studies , tend to support the two - step scenario , where the solid and liquid phases are separated by a third , so called hexatic phase . we have performed molecular dynamics simulations on yukawa ( debye - hckel ) systems at conditions earlier predicted to belong to the hexatic phase . our simulation studies on the time needed for the equilibration of the systems conclude that the hexatic phase is metastable and disappears in the limit of long times . we also show that simply increasing the particle number in particle simulations does not necessarily result in more accurate conclusions regarding the existence of the hexatic phase . the increase of the system size has to be accompanied with the increase of the simulation time to ensure properly thermalized conditions . . And you have already written the first three sentences of the full article: the debate about the properties of the melting phase transition of two - dimensional ( 2d ) systems did not lose its intensity over the past several decades . recent developments in the fabrication of 2d materials @xcite simultaneously seek for , and may provide clarification of the details of the transition . a milestone , and still the most widely accepted theory available , is the kosterlitz - thouless - halperin - nelson - young ( kthny ) picture @xcite . in the underlying physical process. Please generate the next two sentences of the article

two separate , continuous transitions can be distinguished , as the solid transforms into a liquid in quasi - equilibrium steps by slow heating . during the first stage the translational ( positional ) order vanishes , while in the second stage the orientational order decays . all this is mediated by the unbinding of ( i ) dislocation pairs into individual dislocations , and ( ii ) dislocations into point defects @xcite . the strength of this theory consists in its compatibility with the mermin - wagner theorem that forbids the existence of exact long range positional order in 2d for a wide range of pair potentials , at finite temperatures @xcite .

Suppose that you have an abstract for a scientific paper: we survey the role of symmetry in diffeomorphic registration of landmarks , curves , surfaces , images and higher - order data . the infinite dimensional problem of finding correspondences between objects can for a range of concrete data types be reduced resulting in compact representations of shape and spatial structure . this reduction is possible because the available data is incomplete in encoding the full deformation model . using reduction by symmetry , we describe the reduced models in a common theoretical framework that draws on links between the registration problem and geometric mechanics . symmetry also arises in reduction to the lie algebra using particle relabeling symmetry allowing the equations of motion to be written purely in terms of eulerian velocity field . reduction by symmetry has recently been applied for jet - matching and higher - order discrete approximations of the image matching problem . we outline these constructions and further cases where reduction by symmetry promises new approaches to registration of complex data types . . And you have already written the first three sentences of the full article: registration , the task of establishing correspondences between multiple instances of objects such as images , landmarks , curves , and surfaces , plays a fundamental role in a range of computer vision applications including shape modeling @xcite , motion compensation and optical flow @xcite , remote sension @xcite , and medical imaging @xcite . in the subfield of computational anatomy @xcite , establishing inter - subject correspondences between organs allows the statistical study of organ shape and shape variability . examples of the fundamental role of registration include quantifying developing alzheimer s disease by establishing correspondences between brain tissue at different stages of the disease @xcite ; measuring the effect of copd on lung tissue after removing the variability caused by the respiratory process @xcite ; and correlating the shape of the hippocampus to schizophrenia after inter - subject registration @xcite . in this paper , we survey the role of symmetry in diffeomorphic registration and deformation modeling and link symmetry as seen from the field of geometric mechanics with the image registration problem .. Please generate the next two sentences of the article

we focus on large deformations modeled in subgroups of the group of diffeomorphic mappings on the spatial domain , the approach contained in the large deformation diffeomorphic metric mapping ( lddmm , @xcite ) framework . connections with geometric mechanics @xcite have highlighted the role of symmetry and resulted in previously known properties connected with the registration of specific data types being described in a common theoretical framework @xcite .

Suppose that you have an abstract for a scientific paper: cern measurements of @xmath0 on polarized target at 17.2 gev / c enable experimental determination of partial wave production amplitudes below 1080 mev . the measured @xmath1-wave transversity amplitudes provide evidence for a narrow scalar resonance @xmath2 . the assumption of analyticity of production amplitudes in dipion mass allows to determine @xmath1-wave helicity amplitudes @xmath3 and @xmath4 . the helicity flip amplitude @xmath4 is related to @xmath5 scattering . there are four `` down '' solutions @xmath6 , @xmath7 , @xmath8 and @xmath9 selected by the unitarity in @xmath5 scattering . ellis - lanik relation between the mass @xmath10 and partial width @xmath11 derived from an effective qcd theory with broken scale and chiral symmetry selects solutions @xmath6 and @xmath8 and imparts the @xmath2 resonance with a dilaton - gluonium interpretation . weinberg s mended symmetry selects solutions @xmath6 and @xmath7 . the combined solution @xmath6 has @xmath12 mev and @xmath13 mev . the observed @xmath14 degeneracy leads to new relations between gluon condensate and pion decay constant and @xmath15 chiral condensate . the two relations are well satisfied . ellis - lanik relation relates the existence of @xmath2 to breaking of scale symmetry in qcd . interaction of chirally invariant and narrow @xmath2 with chirally noninvariant qcd vacuum in @xmath5 scattering is proposed as a possible mechanism for the metamorphosis of @xmath2 into a broad resonant @xmath1-wave structure in @xmath5 related to spontaneous breaking of chiral symmetry in qcd . we comment on possible connections of @xmath2 to cosmological contstant and qcd / string duality in ads / cft brane world model . . And you have already written the first three sentences of the full article: in 1968 , mack , wilson and gell - mann recognized that scale invariance is a broken symmetry of strong interactions@xcite . in 1969 , salam and strathedee showed that to formulate a broken chiral as well as scale symmetry within an effective lagrangian approach one has to assume the existence of a chirally invariant scalar field @xmath16 of dimension 1@xcite . in 1970 , ellis proposed to identify this scalar field with the @xmath17 meson@xcite the existence of which was suggested by earlier measurements of forward - backward asymmetry in @xmath18@xcite . the scalar meson dominance of the trace of the energy - momentum tensor ( also referred to as a partially conserved dilatation current ) has been used to study the couplings of the @xmath17 meson@xcite . with the advent of qcd in 1970 s it has been recognized that the quantization of qcd lagrangian leads to breaking of scale invariance in qcd .. Please generate the next two sentences of the article

the anomalous breaking of scale symmetry results in qcd scale anomaly which was shown@xcite to have the form @xmath19 here @xmath20 and @xmath21 are the gluon field strength and the quark field with running mass @xmath22 . @xmath23 and @xmath24 are the gell - mann @xmath23-function and quark anomalous dimension@xcite . the summation over colour is understood .

Suppose that you have an abstract for a scientific paper: it is suggested in this paper that the ` bare ' strange star might be not bare , and there could be a magnetosphere around it . as a strange star might be an intensely magnetized rotator , the induced unipolar electric field would be large enough to construct a magnetosphere around the strange matter core . this kind of magnetosphere is very similar to that of the rotating magnetized neutron stars discussed by many authors . a magnetosphere will be established very soon through pair production by @xmath0 or two photon processes after a strange star was born in a supernova explosion . it is emphasized that the fact that the strange star surface can not supply charged particles does not stop the formation of a space charge separated magnetosphere around the bare strange star . an accretion crust is quite difficult to come into being around an isolated strange star . therefore the observed radio signals of an rotation - powered pulsar may come from a bare strange stars rather than a neutron stars or a strange star with an accretion crust . the idea , that the radio pulsars are the strange stars without crusts , is supported by some observations . for example , the electron - positron annihilation line in the spectrum of the crab pulsar has been reported ( agrinier et al . 1990 ; massaro et al . 1991 ) ; the iron emission lines have been observed in many x - ray pulsars but never been reported in @xmath1ray emission of radio pulsars . this fact is difficult to be understood if the radio pulsars are the neutron stars where the surface binding energy of iron ions is too low to avoid a ion free - flow from the surface ( neuhauseret et al.1986 , 1987 ) . @xmath2department of geophysics , peking university , beijing 100871 , china + @xmath3chinese academy of sciences - peking university joint beijing + astrophysical center + email : rxxu@bac.pku.edu.cn , gjn@pku.edu.cn + _ sent to astrophysics journal ( part 1 ) on april 11 , 1998 _ elementary particles - pulsars : general - stars :.... And you have already written the first three sentences of the full article: since the first radio pulsar , cp 1919 , was discovered in november 1967 ( hewish , bell , et al . 1968 ) , more and more radio pulsars are found , the number of which reaches about 750 ( becker & trumper 1997 ) . these objects are now almost universally believed to be rotating magnetized neutron stars .. Please generate the next two sentences of the article

however , it was suggested that there might be no neutron star , only strange stars ( e.g. alock et al.1986 ) . hence , one of the very interesting and most fundamental questions is ` what is the nature of pulsars?'(i.e .

Suppose that you have an abstract for a scientific paper: we present a study on the effect of undetected stellar companions on the derived planetary radii for the kepler objects of interest ( kois ) . the current production of the koi list assumes that the each koi is a single star . not accounting for stellar multiplicity statistically biases the planets towards smaller radii . the bias towards smaller radii depends on the properties of the companion stars and whether the planets orbit the primary or the companion stars . defining a planetary radius correction factor @xmath0 , we find that if the kois are assumed to be single , then , _ on average _ , the planetary radii may be underestimated by a factor of @xmath1 . if typical radial velocity and high resolution imaging observations are performed and no companions are detected , this factor reduces to @xmath2 . the correction factor @xmath3 is dependent upon the primary star properties and ranges from @xmath4 for a and f stars to @xmath5 for k and m stars . for missions like k2 and tess where the stars may be closer than the stars in the kepler target sample , observational vetting ( primary imaging ) reduces the radius correction factor to @xmath6 . finally , we show that if the stellar multiplicity rates are not accounted for correctly , occurrence rate calculations for earth - sized planets may overestimate the frequency of small planets by as much as @xmath7% . . And you have already written the first three sentences of the full article: the kepler mission @xcite , with the discovery of over 4100 planetary candidates in 3200 systems , has spawned a revolution in our understanding of planet occurrence rates around stars of all types . one of kepler s profound discoveries is that small planets ( @xmath8 ) are nearly ubiquitous ( e.g. , * ? ? ? * ; * ? ? ?. Please generate the next two sentences of the article

* ; * ? ? ? * ; * ? ? ?

Suppose that you have an abstract for a scientific paper: a configuration space method is developed for binding energy calculations of the lowest energy exciton complexes ( trion , biexciton ) in spatially confined quasi-1d semiconductor nanostructures such as nanowires and nanotubes . quite generally , trions are shown to have greater binding energy in strongly confined structures with small reduced electron - hole masses . biexcitons have greater binding energy in less confined structures with large reduced electron - hole masses . this results in a universal crossover behavior , whereby trions become less stable than biexcitons as the transverse size of the quasi-1d nanostructure increases . the method is also capable of evaluating binding energies for electron - hole complexes in quasi-2d semiconductors such as coupled quantum wells and bilayer van der walls bound heterostructures with advanced optoelectronic properties . . And you have already written the first three sentences of the full article: optical properties of low - dimensional semiconductor nanostructures originate from excitons ( coulomb - bound electron - hole pairs ) and exciton complexes such as biexcitons ( coupled states of two excitons ) and trions ( charged excitons ) . these have pronounced binding energies in nanostructures due to the quantum confinement effect.@xcite the advantage of optoelectronic device applications with low - dimensional semiconductor nanostructures lies in the ability to tune their properties in a controllable way . optical properties of semiconducting carbon nanotubes ( cns ) , in particular , are largely determined by excitons,@xcite and can be tuned by electrostatic doping,@xcite or by means of the quantum confined stark effect.@xcite carbon nanotubes are graphene sheets rolled - up into cylinders of one to a few nanometers in diameter and up to hundreds of microns in length , which can be both metals and semiconductors depending on their diameters and chirality.@xcite over the past decade , optical nanomaterials research has uncovered intriguing optical attributes of their physical properties , lending themselves to a variety of new optoelectronic device applications.@xcite formation of biexcitons and trions , though not detectable in bulk materials at room temperature , play a significant role in quantum confined systems of reduced dimensionality such as quantum wells,@xcite nanowires,@xcite nanotubes,@xcite and quantum dots.@xcite biexciton and trion excitations open up routes for controllable nonlinear optics and spinoptronics applications , respectively .. Please generate the next two sentences of the article

the trion , in particular , has both net charge and spin , and therefore can be controlled by electrical gates while being used for optical spin manipulation , or to investigate correlated carrier dynamics in low - dimensional materials . for conventional semiconductor quantum wells , wires , and dots , the binding energies of negatively or positively charged trions are known to be typically lower than those of biexcitons in the same nanostructure , although the specific trion to biexciton binding energy ratios are strongly sample fabrication dependent.@xcite first experimental evidence for the trion formation in carbon nanotubes was reported by matsunaga et al.@xcite and by santos et al.@xcite on @xmath0-doped ( 7,5 ) and undoped ( 6,5 ) cns , respectively .

Suppose that you have an abstract for a scientific paper: we developed a model for the enhancement of the heat flux by spherical and elongated nano - particles in sheared laminar flows of nano - fluids . besides the heat flux carried by the nanoparticles the model accounts for the contribution of their rotation to the heat flux inside and outside the particles . the rotation of the nanoparticles has a twofold effect , it induces a fluid advection around the particle and it strongly influences the statistical distribution of particle orientations . these dynamical effects , which were not included in existing thermal models , are responsible for changing the thermal properties of flowing fluids as compared to quiescent fluids . the proposed model is strongly supported by extensive numerical simulations , demonstrating a potential increase of the heat flux far beyond the maxwell - garnet limit for the spherical nanoparticles . the road ahead which should lead towards robust predictive models of heat flux enhancement is discussed . . And you have already written the first three sentences of the full article: the enhancement of heat transfer by embedded nano - particles in a fluid subjected to a temperature gradient is an important issue that is expected to help in technological application like solar heating , and various cooling devices , including miniaturized computer processors . accordingly , many experiments were conducted in the last couple of decades @xcite , with a breakthrough announcement from a group at argonne national laboratory , who studied water and oil - based nanofluids containing copper oxide nanopaticles , and found an amazing 60% enhancement in thermal conductivity for only a 5% volume fraction of nanoparticles @xcite . subsequent research has however generated what ref .. Please generate the next two sentences of the article

@xcite referred to as `` an astonishing spectrum of results '' . results in the literature show sometime enhancement in the thermal conductivity compared to the prediction of the maxwell - garnett effective medium theory , and sometime values that are less than the same prediction @xcite .

Suppose that you have an abstract for a scientific paper: nuclear reactors have served as the antineutrino source for many fundamental physics experiments . the techniques developed by these experiments make it possible to use these very weakly interacting particles for a practical purpose . the large flux of antineutrinos that leaves a reactor carries information about two quantities of interest for safeguards : the reactor power and fissile inventory . measurements made with antineutrino detectors could therefore offer an alternative means for verifying the power history and fissile inventory of a reactors , as part of international atomic energy agency ( iaea ) and other reactor safeguards regimes . several efforts to develop this monitoring technique are underway across the globe . . And you have already written the first three sentences of the full article: in the five decades since antineutrinos were first detected using a nuclear reactor as the source @xcite , these facilities have played host to a large number of neutrino physics experiments . during this time our understanding of neutrino physics and the technology used to detect antineutrinos have matured to the extent that it seems feasible to use these particles for nuclear reactor safeguards , as first proposed at this conference three decades ago @xcite . safeguards agencies , such as the iaea , use an ensemble of procedures and technologies to detect diversion of fissile materials from civil nuclear fuel cycle facilities into weapons programs .. Please generate the next two sentences of the article

nuclear reactors are the step in the fuel cycle at which plutonium is produced , so effective reactor safeguards are especially important . current reactor safeguards practice is focused upon tracking fuel assemblies through item accountancy and surveillance , and does not include direct measurements of fissile inventory . while containment and surveillance practices are effective , they are also costly and time consuming for both the agency and the reactor operator

Suppose that you have an abstract for a scientific paper: the modes of silicon disk meta - atoms are investigated , motivated by their use as a building block of huygens metasurfaces . a model based on these modes gives a clear physical explanation of all features in the extinction spectrum , in particular due to the interference between non - orthogonal modes . by performing a vector spherical harmonic expansion of each mode , the complex features of the far - field scattering spectrum are also readily explained . it is shown that in general each mode has contributions from many multipole moments . higher order modes with appropriate symmetry are also able to satisfy the huygens condition , leading to multiple bands of strong forward scattering and suppressed back scattering . these results demonstrate a robust approach to find the modes of nano - photonic scatterers , commonly referred to as quasi - normal modes . by utilising an integral formulation of maxwell s equations , the problem of normalising diverging far - fields is avoided . the approach is implemented in an open - source code . . And you have already written the first three sentences of the full article: dielectric resonators have applications in microwave and optical frequency ranges , including antennas @xcite and as building blocks of impedance - matched huygen s metasurfaces @xcite . approximate methods for finding the modes of dielectric resonators are known @xcite , which usually assume that @xmath0 . these methods are inaccurate for the moderate values of permittivity available at optical frequencies , and more sophisticated methods are needed to account for radiation effects .. Please generate the next two sentences of the article

open nanophotonic resonators such as meta - atoms , nano - antennas and oligomers are typically strongly radiative systems , where loss can not be treated as a perturbation . furthermore , in many nanophotonic systems , material dispersion and losses can not be neglected , further complicating the problem of finding their modes . in radiating and dissipative systems

Suppose that you have an abstract for a scientific paper: a study of cicumnuclear star - forming regions ( cnsfrs ) in several early type spirals has been made in order to investigate their main properties : stellar and gas kinematics , dynamical masses , ionising stellar masses , chemical abundances and other properties of the ionised gas . both high resolution ( r@xmath020000 ) and moderate resolution ( r @xmath0 5000 ) have been used . in some cases these regions , about 100 to 150pc in size , are seen to be composed of several individual star clusters with sizes between 1.5 and 4.9pc estimated from hubble space telescope ( hst ) images . stellar and gas velocity dispersions are found to differ by about 20 to 30km / s with the h@xmath1 emission lines being narrower than both the stellar lines and the [ oiii]@xmath25007lines . the twice ionized oxygen , on the other hand , shows velocity dispersions comparable to those shown by stars . we have applied the virial theorem to estimate dynamical masses of the clusters , assuming that systems are gravitationally bounded and spherically symmetric , and using previously measured sizes . the measured values of the stellar velocity dispersions yield dynamical masses of the order of 10@xmath3 to 10@xmath4 solar masses for the whole cnsfrs . we obtain oxygen abundances which are comparable to those found in high metallicity disc hii regions from direct measurements of electron temperatures and consistent with solar values within the errors . the region with the highest oxygen abundance is r3+r4 in ngc 3504 , 12+log(o / h ) = 8.85 , about 1.5 solar if the solar oxygen abundance is set at the value derived by @xcite , 12+log(o / h)@xmath5 = 8.66@xmath60.05 . the derived n / o ratios are in average larger than those found in high metallicity disc hii regions and they do not seem to follow the trend of n / o vs o / h which marks the secondary behaviour of nitrogen . on the other hand , the s / o ratios span a very narrow range between 0.6 and 0.8 of the solar value . as compared to high metallicity disc.... And you have already written the first three sentences of the full article: the inner ( @xmath8 1kpc ) parts of some spiral galaxies show star formation complexes frequently arranged in an annular pattern around their nuclei . these complexes are sometimes called `` hot spots '' and we will refer to these as circumnuclear starforming regions ( cnsfrs ) . their sizes go from a few tens to a few hundreds of pc ( e.g. * ? ? ?. Please generate the next two sentences of the article

* ) and they seem to be made of an ensamble of hii regions ionised by luminous compact stellar clusters whose sizes , as measured from high spatial resolution hst images , are seen to be of only a few pc . the luminosities of cnsfrs are rather large with absolute visual magnitudes ( m@xmath9 ) between -12 and -17 and h@xmath10 luminosities which are comparable to those shown by 30 dor , the largest hii region in the lmc , and overlap with those shown by hii galaxies ( * ? ? ?

Suppose that you have an abstract for a scientific paper: we propose a new mechanism for the delivery of gas to the heart of galactic nuclei . we show that warm halo clouds must periodically impact galactic centers and potentially deliver a large ( @xmath0 ) mass of gas to the galactic nucleus in a singular event . the impact of an accreting warm halo cloud originating far in the galactic halo can , depending on mixing , produce a nuclear starburst of low metallicity stars as well as low luminosity accretion onto the central black hole . based on multiphase cooling around a @xmath1cdm distribution of halos we calculate the nuclear impact rate , the mass captured by the central black hole and the fraction of active nuclei for impacting cloud masses in the range @xmath2 . if there is moderate braking during cloud infall , our model predicts an average fraction of low luminosity active nuclei consistent with observations . . And you have already written the first three sentences of the full article: activity in galactic nuclei is fuelled by a reservoir of low angular momentum gas , but it is unclear how such reservoirs build up . fast outflows from ob stars , supernovae or agn activity can clear out nuclear ism @xcite . gas in the nucleus can also be quickly consumed by star formation @xcite or driven outwards by positive gravitational torques @xcite . if the gas in the reservoir originates outside the nucleus , multiple mechanisms operating on different distance- and time - scales , such as bars feeding nuclear rings @xcite , radiation drag @xcite or interactions @xcite are required . from observations , around @xmath3 of all galactic nuclei in the local universe exhibit low luminosity nuclear activity @xcite , so the mechanism promoting nuclear gas build up is likely to be simple and on - going . in this letter. Please generate the next two sentences of the article

we propose a new mechanism for delivery of gas to the galactic nucleus . we show that the impact of a warm halo cloud ( whc ) , containing @xmath4 , on the central regions of a galaxy will fuel nuclear activity . we develop a simplistic model of this phenomenon to demonstrate its likely importance . while there remains considerable uncertainty in whc parameters , we show that for plausible input parameters , a direct hit by a single whc on the center of a galaxy will supply fuel for star formation and radiatively inefficient accretion onto the central black hole .

Suppose that you have an abstract for a scientific paper: the different kinds of behaviour of three - body systems in the weak binding limit are classified with specific attention to the transition from a true three - body system to an effective two - body system . for weakly bound borromean systems approaching the limit of binding we show that the size - binding energy relation is an almost universal function of the three @xmath0-wave scattering lengths measured in units of a hyperradial scaling parameter defined as a mass weighted average of two - body equivalent square well radii . we explain why three - body halos follow this curve and why systems appearing above reveal two - body substructures . three - body quantum halos 2 - 3 times larger than the limit set by zero hypermoment are possible . . And you have already written the first three sentences of the full article: attempts for a general classification of halo states were started early in the development of the field , see e.g. @xcite , and have recently led to the suggested definition of halo states @xcite as having more than 50% probability of being in a cluster configuration where more than 50% of this probability should be in a classically forbidden region . this definition is straightforward to apply for a two - body system , where one basically has to find the outer classical turning point in the radial motion . the three - body systems are more challenging @xcite and it is the purpose of this paper to discuss their possible modes of behaviour . one obvious point that needs clarification is how to generalize the outer classical turning point , that also can be used @xcite to scale different halo systems so that e.g. nuclear and molecular halos can be compared in dimensionless units .. Please generate the next two sentences of the article

for the interesting special case of efimov states a universal scaling property predicting one efimov state from the previous one has been developed , see @xcite . another point that has only been discussed briefly in the literature so far is how the transition from a three - body to a two - body state takes place as the binding potentials are changed @xcite .

Suppose that you have an abstract for a scientific paper: we prove that a certain spinfoam model for euclidean quantum general relativity , recently defined , is finite : all its all feynman diagrams converge . the model is a variant of the barrett - crane model , and is defined in terms of a field theory over @xmath0 . -.25 in . And you have already written the first three sentences of the full article: in reference @xcite , barrett and crane have introduced a model for quantum general relativity ( gr ) . the model is based on the topological quantum @xmath1 bf theory , and is obtained by adding a quantum implementation of the constraint that reduces classical bf theory to euclidean gr @xcite . to make use of the barrett - crane construction in quantum gravity , two issues need to be addressed . first , in order to control the divergences in the sum defining the model , the barrett - crane model is defined in terms of the @xmath2-deformation of @xmath1 . in a realistic model for quantum euclidean. Please generate the next two sentences of the article

gr , one would like the limit @xmath3 to be well defined . second , the barrett - crane model is defined over a fixed triangulation .

Suppose that you have an abstract for a scientific paper: we investigate a rheological property of a dense granular material under shear . by a numerical experiment of the system with constant volume , we find a critical volume fraction at which the shear stress and the pressure behave as power - law functions of the shear strain rate . we also present a simple scaling argument that determines the power - law exponents . using these results , we interpret a power - law behavior observed in the system under constant pressure . . And you have already written the first three sentences of the full article: soft glassy systems such as foams , colloidal suspensions , emulsions , polymers , glasses @xcite , and granular materials @xcite have a strongly non - linear response to an external perturbation . in such systems , the relation between the stress @xmath0 and the strain rate @xmath1 characterizes the system behavior . although it is known that the relations are diverse and specific to individual systems , a universal law for a certain class of systems may exist . in particular , in sheared granular materials under constant pressure @xmath2 , one of the authors ( hatano ) has found a relation @xcite @xmath3 with @xmath4 by a numerical experiment using the discrete element method . here , @xmath5 is the maximum diameter of the particles ( their diameters are uniformly distributed in the range @xmath6 $ ] ) and @xmath7 is the mass of the particles @xcite . as demonstrated in fig .. Please generate the next two sentences of the article

[ fig : hatano ] , the exponent @xmath8 is not inconsistent with @xmath9 in the range @xmath10 . surprisingly , the power - law behavior given in eq . ( [ hatano : power ] ) is observed in the cases that @xmath11 and @xmath12 , where @xmath13 represents the young modulus of the particle .

Suppose that you have an abstract for a scientific paper: we calculate in detail the expected properties of low redshift dlas under the assumption that they arise in the gaseous disks of galaxies like those in the @xmath0 population . a sample of 355 nearby galaxies is analysed , for which high quality hi 21-cm emission line maps are available as part of an extensive survey with the westerbork telescope ( whisp ) . we find that expected luminosities , impact parameters between quasars and dla host galaxies , and metal abundances are in good agreement with the observed properties of dlas and dla galaxies . the measured redshift number density of @xmath1 gas above the dla limit is @xmath2 , which compared to higher @xmath3 measurements implies that there is no evolution in the comoving density of dlas along a line of sight between @xmath4 and @xmath1 , and a decrease of only a factor of two from @xmath5 to the present time . we conclude that the local galaxy population can explain all properties of low redshift dlas . galaxies : ism ; ( galaxies : ) quasars : absorption lines ; galaxies : evolution . And you have already written the first three sentences of the full article: the range of hi column densities typically seen in routine 21-cm emission line observations of the neutral gas disks in nearby galaxies is very similar to those that characterise the damped lyman-@xmath6 systems or dlas with @xmath7 . an attractive experiment would therefore be to map the hi gas of dla absorbing systems in 21-cm emission , and measure the dlas total gas mass , the extent of the gas disks and their dynamics . this would provide a direct observational link between dlas and local galaxies , but unfortunately such studies are impossible with present technology ( see e.g. , kanekar et al .. Please generate the next two sentences of the article

the transition probability of the hyperfine splitting that causes the 21-cm line is extremely small , resulting in a weak line that can only be observed in emission in the very local ( @xmath8 ) universe , with present technology . on the other hand , the identification of dlas as absorbers in background qso spectra is , to first order , not distance dependent because the detection efficiency depends mostly on the brightness of the background source , not on the redshift of the absorber itself .

Suppose that you have an abstract for a scientific paper: we have developed a numerical software library for collisionless @xmath0-body simulations named `` phantom - grape '' which highly accelerates force calculations among particles by use of a new simd instruction set extension to the x86 architecture , advanced vector extensions ( avx ) , an enhanced version of the streaming simd extensions ( sse ) . in our library , not only the newton s forces , but also central forces with an arbitrary shape @xmath1 , which has a finite cutoff radius @xmath2 ( i.e. @xmath3 at @xmath4 ) , can be quickly computed . in computing such central forces with an arbitrary force shape @xmath1 , we refer to a pre - calculated look - up table . we also present a new scheme to create the look - up table whose binning is optimal to keep good accuracy in computing forces and whose size is small enough to avoid cache misses . using an intel core i72600 processor , we measure the performance of our library for both of the newton s forces and the arbitrarily shaped central forces . in the case of newton s forces , we achieve @xmath5 interactions per second with one processor core ( or @xmath6 gflops if we count @xmath7 operations per interaction ) , which is @xmath8 times higher than the performance of an implementation without any explicit use of simd instructions , and @xmath9 times than that with the sse instructions . with four processor cores , we obtain the performance of @xmath10 interactions per second ( or @xmath11 gflops ) . in the case of the arbitrarily shaped central forces , we can calculate @xmath12 and @xmath13 interactions per second with one and four processor cores , respectively . the performance with one processor core is @xmath14 times and @xmath9 times higher than those of the implementations without any use of simd instructions and with the sse instructions . these performances depend only weakly on the number of particles , irrespective of the force shape . it is good contrast with the fact that the performance of force calculations accelerated by.... And you have already written the first three sentences of the full article: self - gravity is one of the most essential physical processes in the universe , and plays important roles in almost all categories of astronomical objects such as globular clusters , galaxies , galaxy clusters , etc . in order to follow the evolution of such systems , gravitational @xmath0-body solvers have been widely used in numerical astrophysics . due to prohibitively expensive computational cost in directly solving @xmath0-body problems , many efforts have been made to reduce it in various ways . for example , several sophisticated algorithms to compute gravitational forces among many particles with reduced computational cost have been developed , such as tree method @xcite , pppm method @xcite , treepm method @xcite , etc .. Please generate the next two sentences of the article

another approach is to improve the computational performance with the aid of additional hardware , such as grape ( gravity pipe ) systems , special - purpose accelerators for gravitational @xmath0-body simulations @xcite , and general - purpose computing on graphics processing units ( gpgpus ) . grape systems have been used for further improvement of existing @xmath0-body solvers such as tree method @xcite , pppm method @xcite , treepm method @xcite , p@xmath15m@xmath15 tree method @xcite , and pppt method @xcite .

Suppose that you have an abstract for a scientific paper: fifth generation ( 5 g ) wireless networks face various challenges in order to support large - scale heterogeneous traffic and users , therefore new modulation and multiple access ( ma ) schemes are being developed to meet the changing demands . as this research space is ever increasing , it becomes more important to analyze the various approaches , therefore in this article we present a comprehensive overview of the most promising modulation and ma schemes for 5 g networks . we first introduce the different types of modulation that indicate their potential for orthogonal multiple access ( oma ) schemes and compare their performance in terms of spectral efficiency , out - of - band leakage , and bit - error rate . we then pay close attention to various types of non - orthogonal multiple access ( noma ) candidates , including power - domain noma , code - domain noma , and noma multiplexing in multiple domains . from this exploration we can identify the opportunities and challenges that will have significant impact on the design of modulation and ma for 5 g networks . 5 g , modulation , non - orthogonal multiple access . . And you have already written the first three sentences of the full article: in recent years , fifth generation ( 5 g ) wireless networks have attracted extensive research interest . according to the 3rd generation partnership project ( 3gpp ) @xcite , 5 g networks should support three major families of applications , including enhanced mobile broadband ( embb ) @xcite ; massive machine type communications ( mmtc ) @xcite ; and ultra - reliable and low - latency communications ( urllc ) @xcite . on top of this , enhanced vehicle - to - everything ( ev2x ) communications are also considered as an important service that should be supported by 5 g networks @xcite . these scenarios require massive connectivity with high system throughput and improved spectral efficiency ( se ) and impose significant challenges to the design of general 5 g networks . in order to meet these new requirements , new modulation and multiple access ( ma ). Please generate the next two sentences of the article

schemes are being explored . orthogonal frequency division multiplexing ( ofdm ) @xcite has been adopted in fourth generation ( 4 g ) networks . with an appropriate cyclic prefix ( cp ) , ofdm is able to combat the delay spread of wireless channels with simple detection methods , which makes it a popular solution for current broadband transmission .

Suppose that you have an abstract for a scientific paper: we report the detection of extended low radio frequency continuum emission beyond the optical disk of the spiral galaxy ngc 4254 using the giant metrewave radio telescope . ngc 4254 , which has an almost face - on orientation , is located in the outskirts of the virgo cluster . since such extended emission is uncommon in low inclination galaxies , we believe it is a signature of magnetised plasma pushed out of the disk by ram pressure of the intracluster medium as ngc 4254 falls into the virgo cluster . the detailed spectral index distribution across ngc 4254 shows that the steepest spectrum @xmath0 ( @xmath1 ) arises in the gas beyond the optical disk . this lends support to the ram pressure scenario by indicating that the extended emission is not from the disk gas but from matter which has been stripped by ram pressure . the steeper spectrum of the extended emission is reminiscent of haloes in edge - on galaxies . the sharp fall in intensity and enhanced polarization in the south of the galaxy , in addition to enhanced star formation reported by others provide evidence towards the efficacy of ram pressure on this galaxy . hi 21 cm observations show that the gas in the north lags in rotation and hence is likely the atomic gas which is carried along with the wind . ngc 4254 is a particularly strong radio emitter with a power of @xmath2 watts - hz@xmath3 at 240 mhz . we find that the integrated spectrum of the galaxy flattens at lower frequencies and is well explained by an injection spectrum with @xmath4 . we end by comparing published simulation results with our data and conclude that ram pressure stripping is likely to be a significant contributor to evolution of galaxies residing in x - ray poor groups and cluster outskirts . . And you have already written the first three sentences of the full article: galaxy mergers ( toomre 1977 ) , galaxy harassment ( moore et al . 1996 ) , ram pressure ( gunn & gott 1972 ) , viscous stripping ( nulsen 1982 ) and dynamical friction ( lecar 1975 , chandrasekhar 1943 ) are believed to play a role in the evolution of galaxies in a cluster enviroment and have explained numerous observational results . different physical mechanisms dominate in different environments .. Please generate the next two sentences of the article

while ram pressure effects are believed to be dominant in the dense inner regions of clusters , tidal interactions are believed to dominate the evolution in the cluster outskirts and in groups of galaxies . however , this picture has been undergoing a gradual paradigm shift as demonstrated by observations , especially at radio frequencies , and simulations of groups and outskirts of clusters ( e.g. virgo ) conducted by various authors . the virgo cluster galaxies have been extensively studied in radio and other wavebands e.g. in hi 21 cm by davies , et al .

Suppose that you have an abstract for a scientific paper: an analysis is made of the fine structure in the cosmic ray energy spectrum : new facets of present observations and their interpretation and the next step . it is argued that less than about 10% of the intensity of the helium ` peak ' at the knee at @xmath0 is due to just a few sources ( snr ) other than the single source . the apparent concavity in the rigidity spectra of protons and helium nuclei which have maximum curvature at about 200 gv is confirmed by a joint analysis of the pamela , cream and atic experiments . the spectra of heavier nuclei also show remarkable structure in the form of ` ankles ' at several hundred gev / nucleon . possible mechanisms are discussed . the search for ` pulsar peaks ' has not yet proved successful . . And you have already written the first three sentences of the full article: the search for the origin of cosmic rays ( cr ) is a continuing one . although many incline to the view that supernova remnants ( snr ) are responsible , it is also possible that pulsars contribute and other possibilities include distributed acceleration . to distinguish between them is not a trivial task but is attempted here , by way of studies of the detailed shape , or ` fine structure ' , of the cr spectrum . our claim that a ` single source ' is largely responsible for the characteristic knee in the spectrum ( erlykin and wolfendale , 1997 , 2001 ) has received support from later , more precise , measurements . very recently ( erlykin and wolfendale , 2011a , b ) , we have put forward the case for further fine structure in the energy spectrum in the knee region which appears to be due to the main nuclear ` groups ' : p , he , cno and fe , but this awaits confirmation .. Please generate the next two sentences of the article

what is apparent , however , is that there should be such fine structure in the spectrum and that this structure should give strong clues as to the origin of cr . it is appreciated that there is the danger of over - interpreting the data but , in our view , this is the only way that the subject will advance . for many years

Suppose that you have an abstract for a scientific paper: despite recent advances in uncovering the quantitative features of stationary human activity patterns , many applications , from pandemic prediction to emergency response , require an understanding of how these patterns change when the population encounters unfamiliar conditions . to explore societal response to external perturbations we identified real - time changes in communication and mobility patterns in the vicinity of eight emergencies , such as bomb attacks and earthquakes , comparing these with eight non - emergencies , like concerts and sporting events . we find that communication spikes accompanying emergencies are both spatially and temporally localized , but information about emergencies spreads globally , resulting in communication avalanches that engage in a significant manner the social network of eyewitnesses . these results offer a quantitative view of behavioral changes in human activity under extreme conditions , with potential long - term impact on emergency detection and response . . And you have already written the first three sentences of the full article: current research on human dynamics is limited to data collected under normal and stationary circumstances @xcite , capturing the regular daily activity of individuals @xcite . yet , there is exceptional need to understand how people change their behavior when exposed to rapidly changing or unfamiliar conditions @xcite , such as life - threatening epidemic outbreaks @xcite , emergencies and traffic anomalies , as models based on stationary events are expected to break down under these circumstances . such rapid changes in conditions are often caused by natural , technological or societal disasters , from hurricanes to violent conflicts @xcite .. Please generate the next two sentences of the article

the possibility to study such real time changes has emerged recently thanks to the widespread use of mobile phones , which track both user mobility @xcite and real - time communications along the links of the underlying social network @xcite . here we take advantage of the fact that mobile phones act as _ in situ _ sensors at the site of an emergency , to study the real - time behavioral patterns of the local population under external perturbations caused by emergencies .

Suppose that you have an abstract for a scientific paper: we report the discovery of two damped ly@xmath0 absorption - line systems ( dlas ) near redshift @xmath1 along a single quasar sightline ( q1727 + 5302 ) with neutral hydrogen column densities of @xmath2 and @xmath3 atoms @xmath4 . their sightline velocity difference of 13,000 km s@xmath5 corresponds to a proper separation of 106@xmath6 mpc if interpreted as the hubble flow ( @xmath7 , @xmath8 ) . the random probability of such an occurrence is significantly less than 3% . follow - up spectroscopy reveals neutral gas - phase zn abundances of [ zn / h ] = @xmath9 ( 26.5% solar ) and @xmath10 ( 4.7% solar ) , respectively . the corresponding cr abundances are [ cr / h ] = @xmath11 ( 5.5% solar ) and @xmath12 ( 1.7% solar ) , respectively , which is evidence for depletion onto grains . follow - up ir images show the two most likely dla galaxy candidates to have impact parameters of @xmath13 kpc and @xmath14 kpc if near @xmath1 . they are significantly underluminous relative to the galaxy population at @xmath1 . to investigate the possibility of additional high-@xmath15 absorbers we have searched the sdss database for @xmath16 quasars within 30 arcmin of the original sightline . five were found , and two show strong - absorption near @xmath1 , consistent with classical dla absorption @xmath17% of the time , but almost always @xmath18 atoms @xmath4 . consequently , this rare configuration of four high-@xmath15 absorbers with a total sightline velocity extent of 30,600 km s@xmath5 may represent a large filament - like structure stretching over a proper distance of 241@xmath6 mpc along our sightline , and a region in space capable of harboring excessive amounts of neutral gas . future studies of this region of the sky are encouraged . . And you have already written the first three sentences of the full article: intervening damped ly@xmath0 absorption - line systems ( dlas ) in quasar spectra are very rare , with an incidence of @xmath19 per unit redshift at @xmath1 ( rao , turnshek , & nestor 2004 , hereafter rtn2004 ) . consequently , unless dlas are correlated , the appearance of two dlas along any single quasar sightline ( `` double - damped '' ) represents a very unlikely event . as such , the discovery of any double - damped absorption warrants a closer investigation . here we report the discovery of double - damped absorption near @xmath1 in the sloan digital sky survey ( sdss ) quasar q1727 + 5302 during our most recent _ hubble space telescope _. Please generate the next two sentences of the article

uv spectroscopic survey for dlas ( rtn2004 ) . the purpose of the present paper is to report initial results pertaining to this discovery , and thereby encourage future studies of this region of the sky .

Suppose that you have an abstract for a scientific paper: we present new @xmath0 photometry for the halo globular cluster m30 ( ngc 7099 = c2137 - 174 ) , and compute luminosity functions ( lfs ) in both bands for samples of about 15,000 hydrogen - burning stars from near the tip of the red giant branch ( rgb ) to over four magnitudes below the main - sequence ( ms ) turnoff . we confirm previously observed features of the lf that are at odds with canonical theoretical predictions : an excess of stars on subgiant branch ( sgb ) approximately 0.4 mag above the turnoff and an excess number of rgb stars relative to ms stars . based on subdwarfs with _ hipparcos_-measured parallaxes , we compute apparent distance moduli of @xmath1 and @xmath2 for reddenings of e@xmath3 and 0.02 respectively . the implied luminosity for the horizontal branch ( hb ) at these distances is @xmath4 and 0.37 mag . the two helium indicators we have been able to measure ( @xmath5 and @xmath6 ) both indicate that m30 s helium content is high relative to other clusters of similar metallicity . m30 has a larger value for the parameter @xmath7 than any of the other similarly metal - poor clusters for which this quantity can be reliably measured . this suggests that m30 has either a larger age or higher helium content than all of the other metal - poor clusters examined . the color - difference method for measuring relative ages indicates that m30 is coeval with the metal - poor clusters m68 and m92 . = -0.5 in epsf . And you have already written the first three sentences of the full article: this paper is the second in a series investigating the evolved - star populations in nearby globular clusters . with the large - field ccd imagers now available it is possible to measure nearly complete samples of giant stars in clusters , and at the same time measure stars faint enough that we can normalize the luminosity functions ( lfs ) to the unevolved main sequence . because the lfs for evolved stars directly probe the timescales and fuel consumed in the different phases of stellar evolution , they provide a stringent test of the models for the evolution of low - mass stars . these models are the basis for our use of globular clusters to set a lower limit to the age of the universe and are a fundamental tool in the interpretation of the integrated spectra and colors of elliptical galaxies .. Please generate the next two sentences of the article

the subject of this study is m30 ( ngc 7099 = c2137 - 174 ) , a relatively nearby cluster ( @xmath8 kpc ; peterson 1993 ) at high galactic latitude ( @xmath9 = @xmath10468 ) . m30 has a high central density ( @xmath11 ) , a moderate total mass ( @xmath12 ; pryor & meylan 1993 ) , and is at the metal - poor end of the cluster [ fe / h ] distribution .

Suppose that you have an abstract for a scientific paper: dimer vacancy ( dv ) defect complexes in the si(001)@xmath0 surface were investigated using high - resolution scanning tunneling microscopy and first principles calculations . we find that under low bias filled - state tunneling conditions , isolated ` split - off ' dimers in these defect complexes are imaged as pairs of protrusions while the surrounding si surface dimers appear as the usual `` bean - shaped '' protrusions . we attribute this to the formation of @xmath1-bonds between the two atoms of the split - off dimer and second layer atoms , and present charge density plots to support this assignment . we observe a local brightness enhancement due to strain for different dv complexes and provide the first experimental confirmation of an earlier prediction that the 1 + 2-dv induces less surface strain than other dv complexes . finally , we present a previously unreported triangular shaped split - off dimer defect complex that exists at s@xmath2-type step edges , and propose a structure for this defect involving a bound si monomer . . And you have already written the first three sentences of the full article: there are currently several exciting proposals to use the ( 001 ) surface of silicon for the construction of atomic - scale electronic devices , including single electron transistors @xcite , ultra - dense memories @xcite and quantum computers @xcite . however , since any random charge or spin defects in the vicinity of these devices could potentially destroy their operation , a thorough understanding of the nature of crystalline defects on this surface is essential . the si(001 ) surface was first observed in real space at atomic resolution using scanning tunneling microscopy ( stm ) by tromp _ _ et .. Please generate the next two sentences of the article

al.__@xcite in 1985 . in this study they observed the surface consisted of rows of `` bean - shaped '' protrusions which were interpreted as tunneling from the @xmath1-bonds of surface si dimers , thereby establishing the dimer model as the correct model for this surface . since then , stm has been instrumental in further elucidating the characteristics of this surface , and in particular atomic - scale defects present on the surface@xcite .

Suppose that you have an abstract for a scientific paper: we present a _ chandra _ observation of the central ( @xmath0 kpc ) region of the cluster of galaxies a , rich in interesting phenomena . on large scales ( @xmath1 kpc ) , the x - ray surface brightness is symmetric and slightly elliptical . the cluster has a cool dense core ; the radial temperature gradient varies with position angle . the radial metallicity profile shows a pronounced central drop and an off - center peak . similarly to many clusters with dense cores , a hosts a cold front at @xmath2 kpc south of the center . the gas pressure across the front is discontinuous by a factor @xmath3 , indicating that the cool core is moving with respect to the ambient gas with a mach number @xmath4 . the central dense region inside the cold front shows an unusual x - ray morphology , which consists of a number of x - ray blobs and/or filaments on scales @xmath5 kpc , along with two prominent x - ray cavities . the x - ray blobs are not correlated with either the optical line emission ( h@xmath6[nii ] ) , member galaxies or radio emission . deprojected temperature of the dense blobs is consistent with that of the less dense ambient gas , so these gas phases do not appear to be in thermal pressure equilibrium . an interesting possibility is a significant , unseen non - thermal pressure component in the inter - blob gas , possibly arising from the activity of the central agn . we discuss two models for the origin of the gas blobs hydrodynamic instabilities caused by the observed motion of the gas core , or `` bubbling '' of the core caused by multiple outbursts of the central agn . . And you have already written the first three sentences of the full article: the cores of clusters contain great dynamical complexity . the presence of gas cooling ( fabian 1994 ) , relativistic plasma ejection from the central galaxy ( mcnamara et al . 2000 , fabian et al . 2000 ) , the action of magnetic fields ( taylor , fabian & allen , 2002 ) , possible thermal conduction ( voigt et al . 2002 ) , local star - formation ( allen et al . 1995 ) and substantial masses of cold ( @xmath7 k ) molecular gas ( edge 2001 ) all complicate the simple hydrostatic picture . the launch of _ chandra _ and _ xmm - newton _ have allowed the cores of clusters to be studied in unprecedented detail spatially and spectrally .. Please generate the next two sentences of the article

these advances have led to a number of important results ( e.g. , peterson et al . 2001 ; forman et al .

Suppose that you have an abstract for a scientific paper: we have analyzed all the archival x - ray data of 134 unidentified ( unid ) gamma - ray sources listed in the first _ fermi / lat _ ( 1fgl ) catalog and subsequently followed up by _ swift / xrt_. we constructed the spectral energy distributions ( seds ) from radio to gamma - rays for each x - ray source detected , and tried to pick up unique objects that display anomalous spectral signatures . in these analysis , we target all the 1fgl unid sources , using updated data from the second _ fermi / lat _ ( 2fgl ) catalog on their lat position and spectra . we found several potentially interesting objects , particularly three sources , 1fglj0022.2 - 1850 , 1fglj0038.0 + 1236 and 1fglj0157.0 - 5259 , which were then more deeply observed with as a part of an ao7 program in 2012 . we successfully detected an x - ray counterpart for each source whose x - ray spectra were well fitted by a single power - law function . the positional coincidence with a bright radio counterpart ( currently identified as agn ) in the 2fgl error circles suggests these are definitely the x - ray emission from the same agn , but their seds show a wide variety of behavior . in particular , the sed of 1fglj0038.0 + 1236 is difficult to be explained by conventional emission models of blazars . the source 1fglj0022.2 - 1850 may be in a transition state between a low - frequency peaked bl lac and a high - frequency peaked bl lac object , and 1fglj0157.0 - 5259 could be a rare kind of extreme blazar . we discuss the possible nature of these three sources observed with , together with the x - ray identification results and seds of all 134 sources observed with _ swift_/xrt . . And you have already written the first three sentences of the full article: since the successful launch of the _ fermi _ gamma - ray space telescope in 2008 june , we now have a new opportunity to study gamma - ray emission from different types of high energy sources with much improved sensitivity and localization capabilities than with the egret instrument onboard the _ compton gamma - ray observatory _ ( cgro ) . with the field of view covering 20% of the sky at every moment ( five times larger than egret ) , and its improved sensitivity ( by more than an order of magnitude with respect to egret ) , the large area telescope ( lat ; * ? ? ? * ) aboard _ fermi _ surveys the entire sky each day down to photon flux levels of @xmath0 @xmath1 few @xmath2 . the number of detected gamma - ray sources has increased , with the 2nd catalog ( 2fgl ; * ? ? ?. Please generate the next two sentences of the article

* ) containing 1873 gamma - ray sources in the 100 mev to 100 gev range , while 271 objects were previously listed in the 3rd egret catalog ( 3eg ; * ? ? ? more than 1,000 gamma - ray sources included in the 2fgl are proposed to be associated with active galactic nuclei ( agns ) and 87 sources with pulsars ( psrs ; * ? ? ? * ) , including 21 millisecond pulsars ( msps ) .

Suppose that you have an abstract for a scientific paper: we investigate atom - based electric - field calibration and polarization measurement of a 100-mhz linearly polarized radio - frequency ( rf ) field using cesium rydberg - atom electromagnetically induced transparency ( eit ) in a room - temperature vapor cell . the calibration method is based on matching experimental data with the results of a theoretical floquet model . the utilized 60@xmath0 fine structure floquet levels exhibit @xmath1- and @xmath2-dependent ac stark shifts and splittings , and develop even - order rf - modulation sidebands . the floquet map of cesium 60@xmath0 fine structure states exhibits a series of exact crossings between states of different @xmath2 , which are not rf - coupled . these exact level crossings are employed to perform a rapid and precise ( @xmath3 ) calibration of the rf electric field . we also map out three series of narrow avoided crossings between fine structure floquet levels of equal @xmath2 and different @xmath1 , which are weakly coupled by the rf field via a raman process . the coupling leads to narrow avoided crossings that can also be applied as spectroscopic markers for rf field calibration . we further find that the line - strength ratio of intersecting floquet levels with different @xmath2 provides a fast and robust measurement of the rf field s polarization . . And you have already written the first three sentences of the full article: in the past decades atom - based metrology has had an enormous impact on science , technology and everyday life . seminal advances include microwave and optical atomic clocks @xcite , the global positioning system , and highly sensitive , position - resolved magnetometers @xcite . atom - based field measurement has clear advantages over other field measurement methods because it is calibrating - free , due to the invariance of atomic properties .. Please generate the next two sentences of the article

atom - based metrology has recently expanded into electric - field measurement . an all - optical sensing approach employed by numerous groups is electromagnetically induced transparency ( eit ) of atomic vapors , utilizing rydberg levels @xcite to measure the properties of the electric field .

Suppose that you have an abstract for a scientific paper: in a previous paper we demonstrated that non - radial hydrodynamic oscillations of a thermally - supported ( bonnor - ebert ) sphere embedded in a low - density , high - temperature medium persist for many periods . the predicted column density variations and molecular spectral line profiles are similar to those observed in the bok globule b68 suggesting that the motions in some starless cores may be oscillating perturbations on a thermally supported equilibrium structure . such oscillations can produce molecular line maps which mimic rotation , collapse or expansion , and thus could make determining the dynamical state from such observations alone difficult . however , while b68 is embedded in a very hot , low - density medium , many starless cores are not , having interior / exterior density contrasts closer to unity . in this paper we investigate the oscillation damping rate as a function of the exterior density . for concreteness we use the same interior model employed in broderick et al . ( 2007 ) , with varying models for the exterior gas . we also develop a simple analytical formalism , based upon the linear perturbation analysis of the oscillations , which predicts the contribution to the damping rates due to the excitation of sound waves in the external medium . we find that the damping rate of oscillations on globules in dense molecular environments is always many periods , corresponding to hundreds of thousands of years , and persisting over the inferred lifetimes of the globules . . And you have already written the first three sentences of the full article: the small dark molecular clouds known as starless cores are are significant in the interstellar medium as the potential birthplaces of stars ( review by * ? ? ? as their name implies , the starless cores do not yet contain stars , but their properties are nearly the same as similar small clouds that do @xcite . furthermore , there is a compelling similarity in the mass function of the starless cores @xcite and the initial mass function ( imf ) of stars .. Please generate the next two sentences of the article

observations of bok globules ( bok 1948 ) and starless cores @xcite suggest that many of these small ( m @xmath0 m@xmath1 ) clouds are well described as quasi - equilibrium structures supported mostly by thermal pressure , approximately bonnor - ebert ( be ) spheres @xcite . observed molecular spectral lines @xcite show complex profiles that further suggest velocity and density perturbations within these cores .

Suppose that you have an abstract for a scientific paper: we present the first evidence of a retrograde orbit of the transiting exoplanet hat - p-7b . the discovery is based on a measurement of the rossiter - mclaughlin effect with the subaru hds during a transit of hat - p-7b , which occurred on ut 2008 may 30 . our best - fit model shows that the spin - orbit alignment angle of this planet is @xmath0 @xmath1 . the existence of such a retrograde planet have been predicted by recent planetary migration models considering planet - planet scattering processes or the kozai migration . our finding provides an important milestone that supports such dynamic migration theories . . And you have already written the first three sentences of the full article: one of the surprising properties of extrasolar planets is their distributions around their host stars . since many jovian planets have been found in the vicinity ( far inside the snow line ) of their host stars , numbers of theoretical models have been studied to explain inward planetary migration . recently understanding of planetary migration mechanisms has rapidly progressed through observations of the rossiter - mclaughlin effect ( hereafter the rm effect : @xcite , @xcite ) in transiting exoplanetary systems .. Please generate the next two sentences of the article

the rm effect is an apparent radial velocity anomaly during planetary transits . by measuring this effect , one can learn the sky - projected angle between the stellar spin axis and the planetary orbital axis , denoted by @xmath2 ( see @xcite for theoretical discussion ) .

Suppose that you have an abstract for a scientific paper: we consider a loop mixing of two fermion fields of opposite parities whereas the parity is conserved in a lagrangian . such kind of mixing is specific for fermions and has no analogy in boson case . possible applications of this effect may be related with physics of baryon resonances . the obtained matrix propagator defines a pair of unitary partial amplitudes which describe the production of resonances of spin @xmath0 and different parity @xmath1 or @xmath2 . + the use of our amplitudes for joint description of @xmath3 partial waves @xmath4 and @xmath5 shows that the discussed effect is clearly seen in these partial waves as the specific form of interference between resonance and background . another interesting application of this effect may be a pair of partial waves @xmath6 and @xmath7 where the picture is more complicated due to presence of several resonance states . . And you have already written the first three sentences of the full article: mixing of states ( fields ) is a well - known phenome- non existing in the systems of neutrinos @xcite , quarks @xcite and hadrons . in hadron systems the mixing effects are essential not only for @xmath8- and @xmath9-mesons but also for the broad overlapping resonances . as for theoretical description of mixing phenomena , a general tendency with time and development of experiment consists in transition from a simplified quantum - mechanical description to the quantum field theory methods ( see e.g. review @xcite , more recent papers @xcite and references therein ) . mixing of fermion fields has some specifics as compared with boson case .. Please generate the next two sentences of the article

firstly , there exists @xmath10-matrix structure in a propagator . secondly , fermion and antifermion have the opposite @xmath11-parity , so fermion propagator contains contributions of different parities . as a result , besides a standard mixing of fields with the same quantum numbers , for fermions there exists a mixing of fields with opposite parities ( opf - mixing ) , even if the parity is conserved in lagrangian .

Suppose that you have an abstract for a scientific paper: la@xmath0sr@xmath1nio@xmath2 is well known to have a colossal dielectric constant ( @xmath3 ) . the la@xmath0sr@xmath1nio@xmath2 nanoparticle powder was prepared by a combinational method of solid state reaction and high - energy ball milling . magnetic measurements show that the material has a very small magnetic moment and paramagnetic characteristic at room temperature . the mixture of the nanoparticle powder ( 40@xmath4 vol . ) and paraffin ( 60@xmath4 vol . ) coated in the form of flat layers of different thicknesses ( @xmath5 ) exhibits strong microwave absorption resonances in the 4 - 18 ghz range . the reflection loss ( @xmath6 ) decreases with @xmath5 and reaches down to -36.7 db for @xmath7 mm . the impedance matching ( @xmath8 @xmath9 ) , rather than the phase matching mechanism , is found responsible for the resonance observed in the samples with @xmath10 mm . further increase of the thickness leads to @xmath11 at all frequencies and a reduced absorption . the influence of non - metal backing is also discussed . our observation suggests that la@xmath0sr@xmath1nio@xmath2 nanoparticles could be used as good fillers for high performance radar absorbing material . dielectrics ; electronic materials ; energy storage and conversion ; magnetic materials ; nanoparticles ; powder technology . . And you have already written the first three sentences of the full article: the continuing development and utilization of microwave applications today make electromagnetic interference a serious problem that needs to be solved . although high conductivity metals are very effective for high frequency electromagnetic wave shielding , in many cases they are not suitable when weak or zero reflection is required ( such as for radar stealth technology ) . while metals shield the object by reflecting the incident radiation away , microwave absorbing materials ( mam ) are designed to absorb the radiation and therefore effectively reduce the reflection . strong absorption and weak reflection. Please generate the next two sentences of the article

will lead to a large negative value of reflection loss ( @xmath6 ) and are therefore identified as two strict requirements for high loss mams . minimum @xmath6 values as low as down to less than @xmath12 db have been reported for some materials , most of them are ferri / ferro - magnetic based nanoparticles or composites , _

Suppose that you have an abstract for a scientific paper: an overview is given about the capabilities provided by the jlab 12 gev upgrade to measure deeply virtual exclusive processes with high statistics and covering a large kinematics range in the parameters that are needed to allow reconstruction of a spatial image of the nucleon s quark structure . the measurements planned with clas12 will cross section asymmetries with polarized beams and with longitudinally and transversely polarized proton targets in the constrained kinematics @xmath0 . in addition , unpolarized dvcs cross sections , and doubly polarized beam target asymmetries will be measured as well . in this talk only the beam and target asymmetries will be discussed . . And you have already written the first three sentences of the full article: the concept of gpds @xcite has led to completely new methods of `` spatial imaging '' of the nucleon . the mapping of the nucleon gpds , and a detailed understanding of the spatial quark distribution of the nucleon , have been widely recognized are a key objectives of nuclear physics of the next decade , and is a key justification for the jlab energy upgrade to 12 gev . gpds also allow to quantify how the orbital motion of quarks in the nucleon contributes to the nucleon spin . Please generate the next two sentences of the article

a question of crucial importance for our understanding of the `` mechanics '' underlying nucleon structure . this requires a comprehensive program , combining results of measurements of a variety of processes in electron

Suppose that you have an abstract for a scientific paper: the recent detection of a young pulsar powering `` the mouse '' , g359.230.82 , as well as detailed imaging of surrounding nebular x - ray emission , have motivated us to investigate the structural details and polarization characteristics of the radio emission from this axisymmetric source with a supersonic bow shock . using polarization data at 3.6 and 6 cm , we find that the magnetic field wraps around the bow shock structure near the apex of the system , but downnstream runs parallel to the inferred direction of the pulsar s motion . the rotation measure ( rm ) distribution of the mouse also suggests that the low degree of polarization combined with a high rm ahead of the pulsar result from internal plasma within the bowshock region . in addition , using sub - arcsecond radio image of the mouse , we identify modulations in the brightness distribution of the mouse that may be associated with the unshocked pulsar wind behind the pulsar . lastly , we discuss the relationship between the mouse and its neighboring shell - type supernova remnant g359.10.5 and argue that these two sources could potentially have the same origin . ism : individual : ( g359.230.82 ) , pulsars : individual ( j17472958 ) , stars : neutron , stars : winds , outflows . And you have already written the first three sentences of the full article: g359.230.82 ( `` the mouse '' ) , with its long axisymmetric nonthermal nebula extending for 12 arcminutes , was first discovered as part of a very large array ( vla ) radio continuum survey of the galactic center at 20 cm ( yusef - zadeh and bally 1987 ) . a bow - shock structure was noted along the eastern edge of the nebula ( yusef - zadeh and bally 1989 ) . in addition , radio continuum data show linearly polarized emission from the full extent of the nebula and the spectral index distribution between 2 , 6 and 20 cm remains flat at the head of the nebula but steepens in the direction away from the head of the mouse ( yusef - zadeh and bally 1989 ) . the detection of x - ray emission from this source and the identification of a young radio pulsar g359.230.82 at the head of the nebula resulted in a breakthrough in our understanding of what powers this source ( predehl and kulkarni 1995 ; sidoli et al . 1999 ; camilo et al .. Please generate the next two sentences of the article

more recently , _ chandra _

Suppose that you have an abstract for a scientific paper: numerical utilities of the contact block reduction ( cbr ) method in evaluating the retarded green s function , are discussed for 3-d multi - band open systems that are represented by the atomic tight - binding ( tb ) and continuum @xmath0@xmath1@xmath2 ( kp ) band model . it is shown that the methodology to approximate solutions of open systems which has been already reported for the single - band effective mass model , can not be directly used for atomic tb systems , since the use of a set of zincblende crystal grids makes the inter - coupling matrix be non - invertible . we derive and test an alternative with which the cbr method can be still practical in solving tb systems . this @xmath3-@xmath4 @xmath5 method is validated by a proof of principles on small systems , and also shown to work excellent with the kp approach . further detailed analysis on the accuracy , speed , and scalability on high performance computing clusters , is performed with respect to the reference results obtained by the state - of - the - art recursive green s function and wavefunction algorithm . this work shows that the cbr method could be particularly useful in calculating resonant tunneling features , but show a limited practicality in simulating field effect transistors ( fets ) when the system is described with the atomic tb model . coupled to the kp model , however , the utility of the cbr method can be extended to simulations of nanowire fets . . And you have already written the first three sentences of the full article: semiconductor devices have been continuously downscaled ever since the invention of the first transistor @xcite , such that the size of the single building component of modern electronic devices has already reached to a few nanometers ( nm ) . in such a @xmath6 regime , two conceptual changes are required in the device modeling methodology . one aspect is widely accepted where carriers must be treated as quantum mechanical rather than classical objects . the second change is the need to embrace the multi - band models which can describe atomic features of materials , reproducing experimentally verified bulk bandstuructures . while the single - band effective mass approximation ( ema ) predicts bandstructures reasonably well near the conduction band minimum ( cbm ) , the subband quantization loses accuracy if devices are in a sub - nm regime @xcite .. Please generate the next two sentences of the article

the ema also fails to predict indirect gaps , inter - band coupling and non - parabolicity in bulk bandstructures @xcite . the nearest - neighbor empirical tight - binding ( tb ) and next nearest - neighbor @xmath0@xmath1@xmath2 ( kp ) approach are most widely used band models of multiple bases @xcite .

Suppose that you have an abstract for a scientific paper: @xmath0 decay is studied in the effective theory of heavy quark with infinite mass limit . the leading order heavy flavor - spin independent universal wave functions which parametrize the relevant matrix elements are evaluated via light cone sum rule method in the effective theory . the important quark mixing matrix element @xmath1 is then extracted via @xmath2 decay mode . # 1@xmath3#1 . And you have already written the first three sentences of the full article: weak decays of charmed and beautiful hadrons are quite favorable in particle physics because of their usage in determining fundamental parameters of the standard model and testing various theories and models . among these heavy hadron decays the semileptonic decays @xmath4 and @xmath5 have been observed experimentally . these exclusive decays provide one of the main channels to determine the important ckm matrix element @xmath1 . the difficulty in studying @xmath6 and @xmath5 decays mainly concerns the calculation of the relevant hadronic matrix elements of weak operators , or , equivalently , the corresponding form factors which contain nonperturbative contributions as well as perturbative ones and are beyond the power of pure qcd perturbation theory . up to present these form factors are usually evaluated from lattice calculations , qcd sum rules and some hadronic models .. Please generate the next two sentences of the article

sum rule method has been applied to @xmath7 decay in the full qcd and provided reasonable results@xcite . since the meson b contains a single heavy quark , it is expected that its exclusive decays into light mesons may also be understood well in the effective theory of heavy quark , which explicitly demonstrates the heavy quark spin - flavor symmetry and its breaking effects can systematically be evaluated via the power of inverse heavy quark mass @xmath8 .

Suppose that you have an abstract for a scientific paper: for a quantum system , a density matrix @xmath0 that is not pure can arise , via averaging , from a distribution @xmath1 of its wave function , a normalized vector belonging to its hilbert space @xmath2 . while @xmath0 itself does not determine a unique @xmath1 , additional facts , such as that the system has come to thermal equilibrium , might . it is thus not unreasonable to ask , which @xmath1 , if any , corresponds to a given thermodynamic ensemble ? to answer this question we construct , for any given density matrix @xmath0 , a natural measure on the unit sphere in @xmath2 , denoted @xmath3 . we do this using a suitable projection of the gaussian measure on @xmath2 with covariance @xmath0 . we establish some nice properties of @xmath3 and show that this measure arises naturally when considering macroscopic systems . in particular , we argue that it is the most appropriate choice for systems in thermal equilibrium , described by the canonical ensemble density matrix @xmath4 . @xmath3 may also be relevant to quantum chaos and to the stochastic evolution of open quantum systems , where distributions on @xmath2 are often used . key words : canonical ensemble in quantum theory ; probability measures on hilbert space ; gaussian measures ; density matrices . . And you have already written the first three sentences of the full article: in classical mechanics , ensembles , such as the microcanonical and canonical ensembles , are represented by probability distributions on the phase space . in quantum mechanics , ensembles are usually represented by density matrices . it is natural to regard these density matrices as arising from probability distributions on the ( normalized ) wave functions associated with the thermodynamical ensembles , so that members of the ensemble are represented by a random state vector .. Please generate the next two sentences of the article

there are , however , as is well known , many probability distributions which give rise to the same density matrix , and thus to the same predictions for experimental outcomes @xcite .. the measure that gives equal weight to these two states corresponds to the same density matrix as the one giving equal weight to @xmath5 and @xmath6 . however the physical situation corresponding to the former measure , a mixture of two grotesque superpositions , seems dramatically different from the one corresponding to the latter , a routine mixture .

Suppose that you have an abstract for a scientific paper: we follow the approach of induced matter theory for a five dimensional ( @xmath0 ) vacuum brans dicke theory and introduce induced matter and induced potential in four dimensional ( @xmath1 ) hypersurfaces , and then employ a generalized frw type solution . we confine ourselves to the scalar field and scale factors be functions of the cosmic time . this makes the induced potential , by its definition , vanishes , but the model is capable to expose variety of states for the universe . in general situations , in which the scale factor of the fifth dimension and scalar field are not constants , the @xmath0 equations , for any kind of geometry , admit a power law relation between the scalar field and scale factor of the fifth dimension . hence , the procedure exhibits that @xmath0 vacuum frw like equations are equivalent , in general , to the corresponding @xmath1 vacuum ones with the same spatial scale factor but a new scalar field and a new coupling constant , @xmath2 . we show that the @xmath0 vacuum frw like equations , or its equivalent @xmath1 vacuum ones , admit accelerated solutions . for a constant scalar field , the equations reduce to the usual frw equations with a typical radiation dominated universe . for this situation , we obtain dynamics of scale factors of the ordinary and extra dimensions for any kind of geometry without any _ priori _ assumption among them . for non constant scalar fields and spatially flat geometries , solutions are found to be in the form of power law and exponential ones . we also employ the weak energy condition for the induced matter , that gives two constraints with negative or positive pressures . all types of solutions fulfill the weak energy condition in different ranges . the power law solutions with either negative or positive pressures admit both decelerating and accelerating ones . some solutions accept a shrinking extra dimension . by considering non ghost scalar fields and appealing the recent observational measurements , .... And you have already written the first three sentences of the full article: attempts to geometrical unification of gravity with other interactions , using higher dimensions other than our conventional @xmath1 space time , began shortly after invention of the special relativity ( * sr * ) . nordstrm was the first who built a unified theory on the base of extra dimensions @xcite . tight connection between sr and electrodynamics , namely the lorentz transformation , led kaluza @xcite and klein @xcite to establish @xmath0 versions of general relativity ( * gr * ) in which electrodynamics rises from the extra fifth dimension . since then , considerable amount of works have been focused on this idea either using different mechanism for compactification of extra dimension or generalizing it to non compact scenarios ( see e.g. ref .. Please generate the next two sentences of the article

@xcite ) such as brane world theories @xcite , space time matter or induced matter ( * i m * ) theories @xcite and references therein .

Suppose that you have an abstract for a scientific paper: we study the radiative leptonic decays of heavy mesons within the covariant light - front model . using this model , both the form factors @xmath0 and @xmath1 have the same form when the heavy quark limit is taken . in addition , the relation between the form factor @xmath0 and the decay constant of heavy meson @xmath2 is obtained . the hadronic parameter @xmath3 can be determine by the parameters appearing in the wave function of heavy meson . we find that the value of @xmath3 is not only quite smaller than the one in the non - relativistic case , but also insensitive to the value of light quark mass @xmath4 . these results mean that the relativistic effects are very important in this work . we also obtain the branching ratio of @xmath5 is about @xmath6 , in agreement with the general estimates in the literature . 16 true pt 10 mm . And you have already written the first three sentences of the full article: the understanding of the strong and weak interactions of a heavy quark system is an important topic , and the purely leptonic decays @xmath7 seems to be the useful tools for this purpose . in particular , these processes are very simple in that no hadrons and photons appear in the final states . however , the rates of these purely leptonic decays are helicity suppressed with the factor of @xmath8 for @xmath9 and @xmath10 ( the @xmath11 channel , in spite of no suppression , is hard to observe the decay because of the low efficiency ) . therefore it is natural to extend the purely leptonic @xmath12 decay searches to the corresponding radiative modes @xmath5 .. Please generate the next two sentences of the article

these radiative leptonic decays receive two types of contributions : inner bremsstrahlung ( ib ) and structure - dependent ( sd ) @xcite . as is known , the ib contributions are still helicity suppressed , while the sd ones are reduced by the fine structure constant @xmath13 but they are not suppressed by the lepton mass .

Suppose that you have an abstract for a scientific paper: we investigate the hall effect in a quasi one - dimensional system made of weakly coupled luttinger liquids at half filling . using a memory function approach , we compute the hall coefficient as a function of temperature and frequency in the presence of umklapp scattering . we find a power - law correction to the free - fermion value ( band value ) , with an exponent depending on the luttinger parameter @xmath0 . at sufficiently high temperature or frequency the hall coefficient approaches the band value . . And you have already written the first three sentences of the full article: the hall effect has been continuously playing an important role in experimental condensed - matter research , mostly because the interpretation of hall measurements is rather simple in classical fermi systems @xcite . in such materials the hall coefficient is a remarkably robust property , which is unaffected by interactions and only depends upon the shape of the fermi surface and the sign of the charge carriers . deviations from this simple behavior are generally taken as evidence for the onset of strong correlations and a failure of the fermi - liquid ( fl ) paradigm @xcite .. Please generate the next two sentences of the article

several authors have investigated the hall effect in threeand two - dimensional fl @xcite , but the question of the role of correlations in the hall effect for low - dimensional systems remains largely unexplored . in most three - dimensional systems the interactions play a secondary role and the fl picture is appropriate @xcite .

Suppose that you have an abstract for a scientific paper: the branching ratios and cp violations of the @xmath0 decays , including both the color - allowed and the color - suppressed modes , are investigated in detail within qcd framework by considering all diagrams which lead to three effective currents of two quarks . an intrinsic mass scale as a dynamical gluon mass is introduced to treat the infrared divergence caused by the soft collinear approximation in the endpoint regions , and the cutkosky rule is adopted to deal with a physical - region singularity of the on mass - shell quark propagators . when the dynamical gluon mass @xmath1 is regarded as a universal scale , it is extracted to be around @xmath2 mev from one of the well - measured @xmath0 decay modes . the resulting predictions for all branching ratios are in agreement with the current experimental measurements . as these decays have no penguin contributions , there are no direct @xmath3 asymmetries . due to interference between the cabibbo - suppressed and the cabibbo - favored amplitudes , mixing - induced @xmath3 violations are predicted in the @xmath4 decays to be consistent with the experimental data at 1-@xmath5 level . more precise measurements will be helpful to extract weak angle @xmath6 . . And you have already written the first three sentences of the full article: nonleptonic @xmath7-meson decays are of crucial importance to deepen our insights into the flavor structure of the standard model ( sm ) , the origin of cp violation , and the dynamics of hadronic decays , as well as to search for any signals of new physics beyond the sm . however , due to the non - perturbative strong interactions involved in these decays , the task is hampered by the computation of matrix elements between the initial and the final hadron states . in order to deal with these complicated matrix elements reliably , several novel methods based on the naive factorization approach ( fa ) @xcite , such as the qcd factorization approach ( qcdf ) @xcite , the perturbation qcd method ( pqcd ) @xcite , and the soft - collinear effective theory ( scet ) @xcite , have been developed in the past few years . these methods have been used widely to analyze the hadronic @xmath7-meson decays , while they have very different understandings for the mechanism of those decays , especially for the case of heavy - light final states , such as the @xmath0 decays . presently , all these methods can give good predictions for the color allowed @xmath8 mode , but for the color suppressed @xmath9 mode , the qcdf and the scet methods could not work well , and the pqcd approach seems leading to a reasonable result in comparison with the experimental data .. Please generate the next two sentences of the article

in this situation , it is interesting to study various approaches and find out a reliable approach . as the mesons are regarded as quark and anti - quark bound states , the nonleptonic two body meson decays concern three quark - antiquark pairs .

Suppose that you have an abstract for a scientific paper: we calculate the propagator and the transition probabilities for a coherently driven three - state quantum system . the energies of the three states change linearly in time , whereas the interactions between them are pulse - shaped . we derive a highly accurate analytic approximation by assuming independent pairwise landau - zener transitions occurring instantly at the relevant avoided crossings , and adiabatic evolution elsewhere . quantum interferences are identified , which occur due to different possible evolution paths in hilbert space between an initial and a final state . a detailed comparison with numerical results for gaussian - shaped pulses demonstrates a remarkable accuracy of the analytic approximation . we use the analytic results to derive estimates for the half - width of the excitation profile , and for the parameters required for creation of a maximally coherent superposition of the three states . these results are of potential interest in ladder climbing in alkali atoms by chirped laser pulses , in quantum rotors , in transitions between zeeman sublevels of a @xmath0 level in a magnetic field , and in control of entanglement of a pair of spin-1/2 particles . the results for the three - state system can be generalized , without essential difficulties , to higher dimensions . . And you have already written the first three sentences of the full article: whenever the energies of two discrete quantum states cross when plotted against some parameter , e.g. time , the transition probability is traditionally estimated by the famous landau - zener ( lz ) formula @xcite . although the lz model involves the simplest nontrivial time dependence linearly changing energies and a constant interaction of infinite duration , when applied to real physical systems with more sophisticated time dependences the lz model often provides more accurate results than expected .. Please generate the next two sentences of the article

this feature ( which has not been fully understood yet ) , and the extreme simplicity of the lz transition probability , have determined the vast popularity of the lz model , despite the availability of more sophisticated exactly soluble level - crossing models , e.g. the demkov - kunike model @xcite and its special case , the allen - eberly - hioe model @xcite . numerous extensions of the lz model to multiple levels have been proposed .

Suppose that you have an abstract for a scientific paper: we present detailed luminosity profiles of the young massive clusters m82-f , ngc 1569-a , and ngc 1705 - 1 which show significant departures from equilibrium ( king and eff ) profiles . we compare these profiles with those from @xmath0-body simulations of clusters which have undergone the rapid removal of a significant fraction of their mass due to gas expulsion . we show that the observations and simulations agree very well with each other suggesting that these young clusters are undergoing violent relaxation and are also losing a significant fraction of their _ stellar _ mass . that these clusters are not in equilibrium can explain the discrepant mass - to - light ratios observed in many young clusters with respect to simple stellar population models without resorting to non - standard initial stellar mass functions as claimed for m82-f and ngc 1705 - 1 . we also discuss the effect of rapid gas removal on the complete disruption of a large fraction of young massive clusters ( `` infant mortality '' ) . finally we note that even bound clusters may lose @xmath1 50% of their initial _ stellar _ mass due to rapid gas loss ( `` infant weight - loss '' ) . [ firstpage ] galaxies : star clusters stellar dynamics methods : @xmath0-body simulations . And you have already written the first three sentences of the full article: it is thought that the vast majority of stars are formed in star clusters ( lada & lada 2003 ) . during the collapse and fragmentation of a giant molecular cloud into a star cluster , only a modest percentage ( @xmath2 % ) of the gas is turned into stars ( e.g. lada & lada 2003 ) . thus , during the initial phases of its lifetime , a star cluster will be made up of a combination of gas and stars .. Please generate the next two sentences of the article

however , at the onset of stellar winds and after the first supernovae explosions , enough energy is injected into the gas within the embedded cluster to remove the gas on timescales shorter than a crossing time ( e.g. hills 1980 ; lada et al . 1984 ; goodwin 1997a ) .

Suppose that you have an abstract for a scientific paper: we numerically study influence of a polychromatic perturbation on wave packet dynamics in one - dimensional double - well potential . it is found that time - dependence of the transition probability between the wells shows two kinds of the motion typically , coherent oscillation and irregular fluctuation combined to the delocalization of the wave packet , depending on the perturbation parameters . the coherent motion changes the irregular one as the strength and/or the number of frequency components of the perturbation increases . we discuss a relation between our model and decoherence in comparing with the result under stochastic perturbation . furthermore we compare the quantum fluctuation , tunneling in the quantum dynamics with ones in the semiquantal dynamics . . And you have already written the first three sentences of the full article: quantum fluctuation can suppress chaotic motion of wave packet in the phase space due to the quantum interference , as seen in kicked rotor @xcite . on the contrary , the quantum fluctuation can enhance the chaotic motion of wave packet due to tunneling effect as seen in kicked double - well model @xcite . the relation between chaotic behavior and tunneling phenomenon in classically chaotic systems is interesting and important subject in study of quantum physics @xcite .. Please generate the next two sentences of the article

recently , the semiclassical description for the tunneling phenomena in a classically chaotic system have been developed by several groups @xcite . lin and ballentine studied interplay between the tunneling and classical chaos for a particle in a double - well potential with oscillatory driving force @xcite .

Suppose that you have an abstract for a scientific paper: we study the single electron spectra from @xmath0 and @xmath1meson semileptonic decays in au+au collisions at @xmath2200 , 62.4 , and 19.2 gev by employing the parton - hadron - string dynamics ( phsd ) transport approach that has been shown to reasonably describe the charm dynamics at relativistic - heavy - ion - collider ( rhic ) and large - hadron - collider ( lhc ) energies on a microscopic level . in this approach the initial charm and bottom quarks are produced by using the pythia event generator which is tuned to reproduce the fixed - order next - to - leading logarithm ( fonll ) calculations for charm and bottom production . the produced charm and bottom quarks interact with off - shell ( massive ) partons in the quark - gluon plasma with scattering cross sections which are calculated in the dynamical quasi - particle model ( dqpm ) that is matched to reproduce the equation of state of the partonic system above the deconfinement temperature @xmath3 . at energy densities close to the critical energy density ( @xmath4 0.5 gev/@xmath5 ) the charm and bottom quarks are hadronized into @xmath0 and @xmath1mesons through either coalescence or fragmentation . after hadronization the @xmath0 and @xmath1 mesons interact with the light hadrons by employing the scattering cross sections from an effective lagrangian . the final @xmath0 and @xmath1 mesons then produce single electrons through semileptonic decay . we find that the phsd approach well describes the @xmath6 and elliptic flow @xmath7 of single electrons in au+au collisions at @xmath8 200 and the elliptic flow at @xmath2 62.4 gev from the phenix collaboration , however , the large @xmath6 at @xmath2 62.4 gev is not described at all . furthermore , we make predictions for the @xmath6 of @xmath0mesons and of single electrons at the lower energy of @xmath2 19.2 gev . additionally , the medium modification of the azimuthal angle @xmath9 between a heavy quark and a heavy antiquark is studied . we find that the transverse flow enhances the.... And you have already written the first three sentences of the full article: relativistic heavy - ion collisions are the experiments of choice to generate hot and dense matter in the laboratory . whereas in low energy collisions one produces dense nuclear matter with moderate temperature and large baryon chemical potential @xmath11 , ultra - relativistic collisions at relativistic heavy ion collider ( rhic ) or large hadron collider ( lhc ) energies produce extremely hot matter at small baryon chemical potential . in order to explore the phase diagram of strongly interacting matter as a function of @xmath12 and @xmath11 both type of collisions are mandatory .. Please generate the next two sentences of the article

according to lattice calculations of quantum chromodynamics ( lqcd ) @xcite , the phase transition from hadronic to partonic degrees of freedom ( at vanishing baryon chemical potential @xmath11=0 ) is a crossover . this phase transition is expected to turn into a first order transition at a critical point @xmath13 in the phase diagram with increasing baryon chemical potential @xmath11 .

Suppose that you have an abstract for a scientific paper: we present the decomposition of the stellar velocity ellipsoid using stellar velocity dispersions within a 40@xmath0 wedge about the major - axis ( @xmath1 ) , the epicycle approximation , and the asymmetric drift equation . thus , we employ no fitted forms for @xmath1 and escape interpolation errors resulting from comparisons of the major and minor axes . we apply the theoretical construction of the method to integral field data taken for ngc 3949 and ngc 3982 . we derive the vertical - to - radial velocity dispersion ratio ( @xmath2 ) and find ( 1 ) our decomposition method is accurate and reasonable , ( 2 ) ngc 3982 appears to be rather typical of an sb type galaxy with @xmath3 despite its high surface brightness and small size , and ( 3 ) ngc 3949 has a hot disk with @xmath4 . . And you have already written the first three sentences of the full article: the shape of the stellar velocity ellipsoid , defined by @xmath5 , @xmath6 , and @xmath7 , provides key insights into the dynamical state of a galactic disk : @xmath7:@xmath5 provides a measure of disk heating and @xmath6:@xmath5 yields a check on the validity of the epicycle approximation ( ea ) . additionally , @xmath5 is a key component in measuring the stability criterion and in correcting rotation curves for asymmetric drift ( ad ) , while @xmath7 is required for measuring the disk mass - to - light ratio . the latter is where the diskmass survey focuses ( verheijen et al .. Please generate the next two sentences of the article

2004 , 2005 ) ; however , in anything but face - on systems , @xmath7 must be extracted via decomposition of the line - of - sight ( los ) velocity dispersion . below , we present such a decomposition for two galaxies in the diskmass sample : ngc 3949 and ngc 3982 . previous long - slit studies ( e.g. , shapiro et al . 2003 and references therein ) acquired observations along the major and minor axes and performed the decomposition via the ea and ad equations ; using both dynamical equations overspecifies the problem such that ad is often used as a consistency check .

Suppose that you have an abstract for a scientific paper: raman scattering by h@xmath0 in neptune s atmosphere has significant effects on its reflectivity for @xmath1 0.5 @xmath2 m , producing baseline decreases of @xmath3 20% in a clear atmosphere and @xmath3 10% in a hazy atmosphere . however , few accurate raman calculations are carried out because of their complexity and computational costs . here we present the first radiation transfer algorithm that includes both polarization and raman scattering and facilitates computation of spatially resolved spectra . new calculations show that cochran and trafton s ( 1978 , _ astrophys . j. * 219 * _ , 756 - 762 ) suggestion that light reflected in the deep ch@xmath4 bands is mainly raman scattered is not valid for current estimates of the ch@xmath4vertical distribution , which implies only a 4% raman contribution . comparisons with iue , hst , and groundbased observations confirm that high altitude haze absorption is reducing neptune s geometric albedo by @xmath36% in the 0.22 - 0.26 @xmath2 m range and by @xmath313% in the 0.35 - 0.45 @xmath2 m range . a sample haze model with 0.2 optical depths of 0.2-@xmath2 m radius particles between 0.1 and 0.8 bars fits reasonably well , but is not a unique solution . we used accurate calculations to evaluate several approximations of raman scattering . the karkoschka ( 1994 , _ icarus * 111 * _ , 174 - 192 ) method of applying raman corrections to calculated spectra and removing raman effects from observed spectra is shown to have limited applicability and to undercorrect the depths of weak ch@xmath4 absorption bands . the relatively large q - branch contribution observed by karkoschka is shown to be consistent with current estimates of raman cross sections . the wallace ( 1972 , _ astrophys . j. * 176 * _ , 249 - 257 ) approximation , produces geometric albedo values @xmath35% low as originally proposed , but can be made much more accurate by including a scattering contribution from the vibrational transition . the original pollack ( 1986 , _ icarus * 65 * _.... And you have already written the first three sentences of the full article: because neptune s atmosphere has a relatively low burden of aerosols , its reflected spectrum is strongly influenced by both rayleigh scattering and raman scattering by molecular hydrogen . rayleigh scattering induces polarization that can significantly modify the reflected intensity ( mishchenko 1994 ) , accurate computation of which presents the very large burden of solving the vector radiation transfer equation . sromovsky ( 2004 ) discusses that problem and a new approximation method applicable to low phase angles .. Please generate the next two sentences of the article

accurate treatment of raman scattering is also a computational burden because photons incident at one wavelength lose some energy to rotating and/or vibrating the hydrogen molecule and reappear at longer wavelengths . computation of reflectivity at one wavelength thus requires accounting for contributions from raman scattering at shorter wavelengths .

Suppose that you have an abstract for a scientific paper: we extend a standard stochastic theory to study open quantum systems coupled to generic quantum environments including the three fundamental classes of non - interacting particles : bosons , fermions and spins . in this unified stochastic approach , the generalized stochastic liouville equation ( sle ) formally captures the exact quantum dissipations when noise variables with appropriate statistics for different bath models are applied . anharmonic effects of a non - gaussian bath are precisely encoded in the bath multi - time correlation functions that noise variables have to satisfy . staring from the sle , we devise a family of generalized hierarchical equations by averaging out the noise variables and expand bath multi - time correlation functions in a complete basis of orthonormal functions . the general hiearchical equations constitute systems of linear equations that provide numerically exact simulations of quantum dynamics . for bosonic bath models , our general hierarchical equation of motion reduces exactly to an extended version of hierarchical equation of motion which allows efficient simulation for arbitrary spectral densities and temperature regimes . similar efficiency and flexibility can be achieved for the fermionic bath models within our formalism . the spin bath models can be simulated with two complementary approaches in the presetn formalism . ( i ) they can be viewed as an example of non - gaussian bath models and be directly handled with the general hierarchical equation approach given their multi - time correlation functions . ( ii ) alterantively , each bath spin can be first mapped onto a pair of fermions and be treated as fermionic environments within the present formalism . . And you have already written the first three sentences of the full article: understanding dissipative quantum dynamics of a system embedded in a complex environment is an important topic across various sub - disciplines of physics and chemistry . significant progress in the understanding of condensed phase dynamics have been achieved within the context of a few prototypical models@xcite such as caldeira - leggett model and spin - boson model . in most cases the environment is modeled as a bosonic bath , a set of non - interacting harmonic oscillators whose influences on the system is concisely encoded in a spectral density . the prevalent adoption of bosonic bath models is based on the arguments that knowing the linear response of an environment near equilibrium should be sufficient to predict the dissipative quantum dynamics of the system . despite many important advancements in the quantum dissipation theory have been made with the standard bosonic bath models in the past decades , more and more physical and chemical studies have suggested the essential roles that other bath models assume .. Please generate the next two sentences of the article

we briefly summarize three scenarios below . 1 . a standard bosonic bath model fails to predict the correct electron transfer rate in donor - acceptor complex strongly coupled to some low - frequency intramolecular modes .

Suppose that you have an abstract for a scientific paper: we use molecular dynamics computer simulations to investigate a critical temperature @xmath0 for a dynamical glass transition as proposed by the mode - coupling theory ( mct ) of dense liquids in a glass forming ni@xmath1zr@xmath2-system . the critical temperature @xmath0 are analyzed from different quantities and checked the consistency of the estimated values , i.e. from ( i ) the non - vanishing nonergodicity parameters as asymptotic solutions of the mct equations in the arrested state , ( ii ) the @xmath3-parameters describing the approach of the melt towards the arrested state on the ergodic side , ( iii ) the diffusion coefficients in the melt . the resulting @xmath0 values are found to agree within about 10 @xmath4 . . And you have already written the first three sentences of the full article: the transition from a liquid to an amorphous solid that sometimes occurs upon cooling remains one of the largely unresolved problems of statistical physics @xcite . at the experimental level , the so - called glass transition is generally associated with a sharp increase in the characteristic relaxation times of the system , and a concomitant departure of laboratory measurements from equilibrium . at the theoretical level , it has been proposed that the transition from a liquid to a glassy state is triggered by an underlying thermodynamic ( equilibrium ) transition @xcite ; in that view , an `` ideal '' glass transition is believed to occur at the so - called kauzmann temperature , @xmath5 . at @xmath5 ,. Please generate the next two sentences of the article

it is proposed that only one minimum - energy basin of attraction is accessible to the system . one of the first arguments of this type is due to gibbs and dimarzio @xcite , but more recent studies using replica methods have yielded evidence in support of such a transition in lennard - jones glass formers @xcite .

Suppose that you have an abstract for a scientific paper: we provide a new criterion for the existence of a global cross section to a volume - preserving anosov flow . the criterion is expressed in terms of expansion and contraction rates of the flow and is more general than the previous results of similar kind . . And you have already written the first three sentences of the full article: henri poincar introduced the idea of a cross section to a flow to study the 3-body problem . a global cross section to a flow @xmath0 on a manifold @xmath1 is a codimension one submanifold @xmath2 of @xmath1 such that @xmath2 intersects every orbit of @xmath0 transversely . it is natural to ask whether any given non - singular flow admits one . if @xmath2 is a global cross section for @xmath0 , it is not hard to check that every orbit which starts on @xmath2 returns to @xmath2 after some positive time , defining the poincar first - return map @xmath3 . the analysis of @xmath0 can then be reduced to the study of the map @xmath4 , which in principle can be an easier task .. Please generate the next two sentences of the article

the flow can be reconstructed from the poincar map by suspending it ( cf . , @xcite ) .

Suppose that you have an abstract for a scientific paper: a spoof attack , a subset of presentation attacks , is the use of an artificial replica of a biometric in an attempt to circumvent a biometric sensor . liveness detection , or presentation attack detection , distinguishes between live and fake biometric traits and is based on the principle that additional information can be garnered above and beyond the data procured by a standard authentication system to determine if a biometric measure is authentic . the goals for the liveness detection ( livdet ) competitions are to compare software - based fingerprint liveness detection and artifact detection algorithms ( part 1 ) , as well as fingerprint systems which incorporate liveness detection or artifact detection capabilities ( part 2 ) , using a standardized testing protocol and large quantities of spoof and live tests . the competitions are open to all academic and industrial institutions which have a solution for either software - based or system - based fingerprint liveness detection . the livdet competitions have been hosted in 2009 , 2011 , 2013 and 2015 and have shown themselves to provide a crucial look at the current state of the art in liveness detection schemes . there has been a noticeable increase in the number of participants in livdet competitions as well as a noticeable decrease in error rates across competitions . participants have grown from four to the most recent thirteen submissions for fingerprint part 1 . fingerprints part 2 has held steady at two submissions each competition in 2011 and 2013 and only one for the 2015 edition . the continuous increase of competitors demonstrates a growing interest in the topic . fingerprint , liveness detection , biometric . And you have already written the first three sentences of the full article: among biometrics , fingerprints are probably the best - known and widespread because of the fingerprint properties : universality , durability and individuality . unfortunately it has been shown that fingerprint scanners are vulnerable to presentation attacks with an artificial replica of a fingerprint . therefore , it is important to develop countermeasures to those attacks .. Please generate the next two sentences of the article

numerous methods have been proposed to solve the susceptibility of fingerprint devices to attacks by spoof fingers . one primary countermeasure to spoofing attacks is called `` liveness detection '' or presentation attack detection .

Suppose that you have an abstract for a scientific paper: in this thesis we study the geometry of the fixed point set @xmath0 of a smooth mapping @xmath1 on an @xmath2-dimensional riemannian manifold @xmath3 by computing the asymptotic expansion as @xmath4 of the trace of the deformed heat kernel @xmath5 of the laplace operator on @xmath6 . we assume that the fixed point set is a union of connected components @xmath7 , @xmath8 , each of which is a smooth compact submanifold of @xmath6 with dimension @xmath9 , @xmath10 . there exists the asymptotic expansion as @xmath4 @xmath11 where @xmath12 are scalar invariants on @xmath7 depending on covariant derivatives of the curvature of the metric @xmath13 and symmetrized covariant derivatives of the differential @xmath14 of the mapping @xmath15 , evaluated on @xmath7 . due to the localization principle , it is possible to compute the expansion for each component separately . we develop a generalized laplace method for computing the coefficients @xmath12 in this expansion and compute the coefficients @xmath16 , @xmath17 , and @xmath18 explicitly in the following cases : 1 . @xmath6 is a flat two - dimensional manifold , @xmath0 is a zero- or one - dimensional component of the fixed point set . 2 . @xmath6 is an @xmath2-dimensional curved manifold , @xmath0 is a zero - dimensional component of the fixed point set . we also develop algorithms for computing further coefficients and expressing them in a symmetrization - free form . i would like to express my gratitude to my scientific advisor prof . ivan g. avramidi for arousing my interest in differential geometry and his area of work . for endless hours he spent with me during my years at new mexico tech exploring possible research directions and helping to improve my background where it lacked . he was always ready to answer my questions and it was just impossible to wish for a better mentor ! thanks to my scientific advisor prof . igor b. simonenko at rostov state university , russia . his inexhaustible enthusiasm inspired.... And you have already written the first three sentences of the full article: here we provide a brief review of differential geometry concepts that we will use further . for more detailed treatment of the subject see , for example , @xcite . a topological hausdorff space @xmath6 with a countable base is called an @xmath2-dimensional * manifold * ( without boundary ) , @xmath19 , if , for any point @xmath20 , there exists an open neighborhood @xmath21 of the point @xmath22 , open subset @xmath23 , and homeomorphism @xmath24 . the pair @xmath25 is called a * coordinate chart * or * local coordinates*. we always assume that all manifolds we deal with are smooth .. Please generate the next two sentences of the article

that is , given an @xmath2-dimensional manifold @xmath6 and two coordinate patches @xmath25 and @xmath26 , such that @xmath27 , the corresponding * transition map * @xmath28 is smooth ( infinitely differentiable ) . let @xmath6 be a manifold and @xmath29 be a function on it .

Suppose that you have an abstract for a scientific paper: the existence of doubly charged higgs bosons ( @xmath0 ) is a distinctive feature of the higgs triplet model ( htm ) , in which neutrinos obtain tree - level masses from the vacuum expectation value of a neutral scalar in a triplet representation of @xmath1 . we point out that a large branching ratio for the decay of a singly charged higgs boson to a doubly charged higgs boson via @xmath2 is possible in a sizeable parameter space of the htm . from the production mechanism @xmath3 the above decay mode would give rise to pair production of @xmath0 , with a cross section which can be comparable to that of the standard pair - production mechanism @xmath4 . we suggest that the presence of a sizeable branching ratio for @xmath2 could significantly enhance the detection prospects of @xmath0 in the four - lepton channel . moreover , the decays @xmath5 and @xmath6 from production of the neutral triplet scalars @xmath7 and @xmath8 would also provide an additional source of @xmath9 , which can subsequently decay to @xmath0 . . And you have already written the first three sentences of the full article: the established evidence that neutrinos oscillate and possess small masses @xcite necessitates physics beyond the standard model ( sm ) , which could manifest itself at the cern large hadron collider ( lhc ) and/or in low energy experiments which search for the lepton flavour violation @xcite . consequently , models of neutrino mass generation which can be probed at present and forthcoming experiments are of great phenomenological interest . neutrinos may obtain mass via the vacuum expectation value ( vev ) of a neutral higgs boson in an isospin triplet representation @xcite .. Please generate the next two sentences of the article

a particularly simple implementation of this mechanism of neutrino mass generation is the `` higgs triplet model '' ( htm ) in which the sm lagrangian is augmented solely by @xmath10 which is a @xmath1 triplet of scalar particles with hypercharge @xmath11 @xcite . in the htm , the majorana neutrino mass matrix @xmath12 ( @xmath13 ) is given by the product of a triplet yukawa coupling matrix @xmath14 and a triplet vev ( @xmath15 ) . consequently , the direct connection between @xmath14 and @xmath12 gives rise to phenomenological predictions for processes which depend on @xmath14 because @xmath16 has been restricted well by neutrino oscillation measurements @xcite .

Suppose that you have an abstract for a scientific paper: adiabatic processes are important for studying the dynamics of a time - dependent system . conventionally , the adiabatic processes can only be achieved by varying the system slowly . we speed up both classical and quantum adiabatic processes by adding control protocols . in classical systems , we work out the control protocols by analyzing the classical adiabatic approximation . in quantum systems , we follow the idea of transitionless driving by berry [ _ j . phys . a : math . theor . _ * 42 * 365303 ( 2009 ) ] . such fast - forward adiabatic processes can be performed at arbitrary fast speed , and in the meanwhile reduce the work fluctuation . in both systems , we use a time - dependent harmonic oscillator model to work out explicitly the work function and the work fluctuation in three types of processes : fast - forward adiabatic processes , adiabatic processes , and non - adiabatic processes . we show the significant reduction on work fluctuation in fast - forward adiabatic process . we further illustrate how the fast - forward process improved the converging rate of the jarzynski equality between the work function and the free energy . as an application , we show that the fast - forward process not only maximizes the output power but also improve the efficiency of a quantum engine . . And you have already written the first three sentences of the full article: for all thermodynamical systems , the macroscopic quantities have a fluctuation because of the statistical nature . according to the law of large numbers , the fluctuation is negligible for large system , which means the probability distribution concentrates near the expectation @xcite . but for small systems , the macroscopic quantity spreads in a wide range , which urges us to explore more on the distribution of the quantity . the probability distribution of the work done to the system under a certain process is usually referred as work function . work function , together with work fluctuation of small system have attracted much attention recently @xcite .. Please generate the next two sentences of the article

work function also relates non - equilibrium qualities with the equilibrium ones @xcite . for example , jarzynski equality relates the non - equilibrium work @xmath0 with helmholtz free energy @xmath1 through @xmath2 . in such discussions ,

Suppose that you have an abstract for a scientific paper: dyadic data are common in the social and behavioral sciences , in which members of dyads are correlated due to the interdependence structure within dyads . the analysis of longitudinal dyadic data becomes complex when nonignorable dropouts occur . we propose a fully bayesian selection - model - based approach to analyze longitudinal dyadic data with nonignorable dropouts . we model repeated measures on subjects by a transition model and account for within - dyad correlations by random effects . in the model , we allow subject s outcome to depend on his / her own characteristics and measure history , as well as those of the other member in the dyad . we further account for the nonignorable missing data mechanism using a selection model in which the probability of dropout depends on the missing outcome . we propose a gibbs sampler algorithm to fit the model . simulation studies show that the proposed method effectively addresses the problem of nonignorable dropouts . we illustrate our methodology using a longitudinal breast cancer study . . . And you have already written the first three sentences of the full article: [ secintro ] dyadic data are common in psychosocial and behavioral studies [ @xcite ] . many social phenomena , such as dating and marital relationships , are interpersonal by definition , and , as a result , related observations do not refer to a single person but rather to both persons involved in the dyadic relationship . members of dyads often influence each other s cognitions , emotions and behaviors , which leads to interdependence in a relationship . for example , a husband s ( or wife s ) drinking behavior may lead to lowered marital satisfaction for the wife ( or husband ) .. Please generate the next two sentences of the article

a consequence of interdependence is that observations of the two individuals are correlated . for example , the marital satisfaction scores of husbands and wives tend to be positively correlated .

Suppose that you have an abstract for a scientific paper: the structure of @xmath0=3 low - energy scattering states is described using the hyperspherical harmonics method with realistic hamiltonian models , consisting of two- and three - nucleon interactions . both coordinate and momentum space two - nucleon potential models are considered . . And you have already written the first three sentences of the full article: one of the main ingredients necessary to study few - body nuclear systems is a realistic description of the nuclear interaction . a number of nucleon - nucleon ( @xmath1 ) potentials has been determined in the recent years . they all reproduce the deuteron binding energy and fit a large set of @xmath1 scattering data below the pion - production threshold with a @xmath2/datum of about 1 . among these potentials , we will consider in the present study only the `` phenomenological '' model of ref .. Please generate the next two sentences of the article

@xcite ( av18 ) , and a model based on chiral symmetry derived in ref . @xcite ( n3lo - idaho ) . among the many features of these two models , we note only that the av18 is a local @xmath1 potential model , with a strong short - range repulsion and tensor component , while the n3lo - idaho is a non - local @xmath1 potential model , with a softer short - range repulsion and tensor component than the av18 . as a consequence of these differences , it is interesting to test these potential models studying light nuclear systems . in these systems , a further contribution to the realistic nuclear hamiltonian model comes from the three - nucleon interaction ( tni ) .

Suppose that you have an abstract for a scientific paper: the existence of an anti - decuplet of pentaquark particles has been predicted some year ago within the chiral soliton model . in the last year , several experimental groups have reported evidence for a s=+1 baryon resonance , with mass ranging from 1.52 and 1.55 gev and width less than 25 mev , by looking at the invariant mass of the @xmath0 system . this resonance , has been identified with the lowest mass of the anti - decuplet , the @xmath1 . at the same time , there are a number of experiment , mostly at high energies , that report null results . + an overview of the experimental results so far obtained will be given here together with a review of the second generation experiments currently ongoing and planned at jefferson lab hall b. . And you have already written the first three sentences of the full article: all the well - established particles can be categorized using the constituent quark model which describes light mesons as bound states of @xmath2 pairs , and baryons as bound 3-quarks states . on the other hand , high energy experiments have shown a more complicated internal structure of mesons and baryons made of a swarms of quarks , anti - quarks and gluons . it is then natural to ask wether particles with more complex configurations exists , like for example 5-quarks ( @xmath3 ) states , where the @xmath4 has different flavor than the others quarks .. Please generate the next two sentences of the article

these states , with quark content other than @xmath2 or @xmath5 are termed as _ exotics_. + the idea of exotics has in fact been proposed since the early 70 s but the experimental signals for exotic baryons were so controversial that never rised to a level of certainty sufficient for the particle data group s tables @xcite . till ,

Suppose that you have an abstract for a scientific paper: we present detailed numerical calculations of the mechanical torque induced by quantum fluctuations on two parallel birefringent plates with in plane optical anisotropy , separated by either vacuum or a liquid ( ethanol ) . the torque is found to vary as @xmath0 , where @xmath1 represents the angle between the two optical axes , and its magnitude rapidly increases with decreasing plate separation @xmath2 . for a 40 @xmath3 m diameter disk , made out of either quartz or calcite , kept parallel to a barium titanate plate at @xmath4 nm , the maximum torque ( at @xmath5 ) is of the order of @xmath6 n@xmath7 m . we propose an experiment to observe this torque when the barium titanate plate is immersed in ethanol and the other birefringent disk is placed on top of it . in this case the retarded van der waals ( or casimir - lifshitz ) force between the two birefringent slabs is repulsive . the disk would float parallel to the plate at a distance where its net weight is counterbalanced by the retarded van der waals repulsion , free to rotate in response to very small driving torques . pacs numbers : 12.20.-m,07.10.pz,46.55.+d . And you have already written the first three sentences of the full article: according to quantum electrodynamics , quantum fluctuations of electric and magnetic fields give rise to a zero - point energy that never vanishes , even in the absence of electromagnetic sources@xcite . in 1948 , h. b. g. casimir predicted that , as a consequence , two electrically neutral metallic parallel plates in vacuum , assumed to be perfect conductors , should attract each other with a force inversely proportional to the fourth power of separation@xcite . the plates act as a cavity where only the electromagnetic modes that have nodes on both the walls can exist .. Please generate the next two sentences of the article

the zero - point energy ( per unit area ) when the plates are kept at close distance is smaller than when the plates are at infinite separation . the plates thus attract each other to reduce the energy associated with the fluctuations of the electromagnetic field .

Suppose that you have an abstract for a scientific paper: the paper describes a time - resolved photoemission ( trpes ) apparatus equipped with a yb - doped fiber laser system delivering 1.2-ev pump and 5.9-ev probe pulses at the repetition rate of 95 mhz . time and energy resolutions are 11.3 mev and @xmath0310 fs , respectively ; the latter is estimated by performing trpes on a highly oriented pyrolytic graphite ( hopg ) . the high repetition rate is suited for achieving high signal - to - noise ratio in trpes spectra , thereby facilitating investigations of ultrafast electronic dynamics in the low pump fluence ( @xmath1 ) region . trpes of polycrystalline bismuth ( bi ) at @xmath1 as low as 30 nj / mm@xmath2 is demonstrated . the laser source is compact and is docked to an existing trpes apparatus based on a 250-khz ti : sapphire laser system . the 95-mhz system is less prone to space - charge broadening effects compared to the 250-khz system , which we explicitly show in a systematic probe - power dependency of the fermi cutoff of polycrystalline gold . we also describe that the trpes response of an oriented bi(111)/hopg sample is useful for fine - tuning the spatial overlap of the pump and probe beams even when @xmath1 is as low as 30 nj / mm@xmath2 . . And you have already written the first three sentences of the full article: a non - equilibrated state of matter triggered by an ultrashort light pulse is acquiring great interest from both fundamental and application points of view @xcite . the impact by the pulse can induce a variety of phenomena including coherent oscillations , ultrafast phase transitions , and femtosecond laser ablations that are applicable to micromachining @xcite , thin film growth @xcite , and clinical surgery @xcite . the pulse may drive a solid state into warm - dense matter @xcite , the extreme temperature and pressure of which mimic the conditions in the core of planets and stars @xcite . the out - of - equilibrium phenomena can be studied by femtosecond pump - and - probe methods @xcite , in which a probe pulse snapshots the sample impacted by a pump pulse .. Please generate the next two sentences of the article

time - resolved photoemission spectroscopy ( trpes ) has become a powerful tool to investigate the non - equilibrium properties of solid state matter from an electronic perspective @xcite . in trpes , a probing pulse has the photon energy that exceeds the work function , so that it can generate photoelectrons through a one - photon process : the distribution of the photoelectrons in energy and angle carries the information of the electronic structures .

Suppose that you have an abstract for a scientific paper: we have obtained deep near - infrared images in j and k filters of three fields in the sculptor galaxy ngc 300 with the eso vlt and isaac camera . for 16 cepheid variables in these fields , we have determined j and k magnitudes at two different epochs , and have derived their mean magnitudes in these bands . the slopes of the resulting period - luminosity relations are in very good agreement with the slopes of these relations measured in the lmc by persson et al . fitting the lmc slopes to our data , we have derived distance moduli in j and k. using these values together with the values derived in the optical v and i bands in our previous work , we have determined an improved total reddening for ngc 300 of e(b - v)=0.096 @xmath0 0.006 mag , which yields extremely consistent values for the absorption - corrected distance modulus of the galaxy from vijk bands . our distance result for ngc 300 from this combined optical / near infrared cepheid study is @xmath1=26.37 @xmath0 0.04 ( random ) @xmath0 0.03 ( systematic ) mag and is tied to an adopted true lmc distance modulus of 18.50 mag . both random and systematic uncertainties are dominated by photometric errors , while errors due to reddening , metallicity effects and crowding are less important . our distance determination is consistent with the earlier result from near - infrared ( h - band ) photometry of two cepheids in ngc 300 by madore et al . , but far more accurate . our distance value also agrees with the hst key project result of freedman et al . , and with the recent distance estimate for ngc 300 from butler et al . from the trgb i - band magnitude when our improved reddening is used to calculate the absorption corrections . our distance results from the different optical and near - infrared bands indicate that the reddening law in ngc 300 must be very similar to the galactic one . with the result from this work , the distance of ngc 300 relative to the lmc seems now determined with an accuracy of @xmath2 @xmath0 3 percent . .... And you have already written the first three sentences of the full article: cepheid variables are arguably the most important stellar standard candles to calibrate the range of a few kiloparsecs out to some 30 megaparsecs on the extragalactic distance ladder . the hst key project on the extragalactic distance scale ( freedman et al . 2001 ) has used cepheid photometry in optical v and i bands in some 25 nearby resolved spiral and irregular galaxies to improve on the value of the hubble constant . there are reasons to believe that cepheids are even better standard candles when they are used in the near - infrared regime .. Please generate the next two sentences of the article

yet , only few galaxies have to date cepheid observations in the near - infrared , and usually few variables have been observed in these galaxies which have not been sufficient to significantly improve on the distance determinations which have been made in optical bands . a recent example is the work of the hst key project team which used the nicmos camera onboard hst to obtain follow - up observations of a number of cepheids in several of the key project galaxies which had previously been surveyed for cepheids in vi passbands ( macri et al .

Suppose that you have an abstract for a scientific paper: we study how the multi - channel kondo effect is dynamically induced to affect the photoemission and the inverse photoemission spectrum when an electron is emitted from ( or added to ) the completely screened kondo impurity with spin @xmath0 . the spectrum thereby shows a power - law edge singularity characteristic of the multi - channel kondo model . we discuss this anomalous behavior by using the exact solution of the multi - channel kondo model and boundary conformal field theory . the idea is further applied to the photoemission for quantum spin systems , in which the edge singularity is controlled by the dynamically induced overscreening effect with a _ mobile _ kondo impurity . . And you have already written the first three sentences of the full article: the multi - channel kondo effect@xcite has been the subject of intensive theoretical @xcite and experimental@xcite studies , which is characterized by unusual non - fermi liquid behaviors . its applications are now extended not only to standard dilute magnetic alloys , but also to quantum dots , etc . thus far , theoretical and experimental studies on the multi - channel kondo effect have been focused on a _ static _ kondo impurity , which has been related to the measurements of the specific heat , the spin susceptibility , the resistivity , etc .. Please generate the next two sentences of the article

this naturally motivates us to address a question whether such a nontrivial phenomenon can be observed in dynamically generated situations . the photoemission and the inverse photoemission may be one of the key experiments to study non - fermi liquid behaviors , which reveal the dynamics of a single hole or electron suddenly created in the system .

Suppose that you have an abstract for a scientific paper: we present a new approach of topology biased random walks for undirected networks . we focus on a one parameter family of biases and by using a formal analogy with perturbation theory in quantum mechanics we investigate the features of biased random walks . this analogy is extended through the use of parametric equations of motion ( pem ) to study the features of random walks _ vs. _ parameter values . furthermore , we show an analysis of the spectral gap maximum associated to the value of the second eigenvalue of the transition matrix related to the relaxation rate to the stationary state . applications of these studies allow _ ad hoc _ algorithms for the exploration of complex networks and their communities . . And you have already written the first three sentences of the full article: the study of complex networks has notably increased in the last years with applications to a variety of fields ranging from computer science@xcite and biology to social science@xcite and finance@xcite . a central problem in network science @xcite is the study of the random walks ( rw ) on a graph , and in particular of the relation between the topological properties of the network and the properties of diffusion on it . this subject is not only interesting from a purely theoretical perspective , but it has important implications to various scientific issues ranging from epidemics @xcite to the classification of web pages through pagerank algorithm @xcite .. Please generate the next two sentences of the article

finally , rw theory is also used in algorithms for community detection @xcite . in this paper we set up a new framework for the study of topologically biased random walks on graphs .

Suppose that you have an abstract for a scientific paper: _ xmm - newton _ x - ray spectra of the hard state black hole x - ray binaries ( bhxrbs ) swift j1753.5 - 0127 and gx 339 - 4 show evidence for accretion disc blackbody emission , in addition to hard power - laws . the soft and hard band power - spectral densities ( psds ) of these sources demonstrate variability over a wide range of time - scales . however , on time - scales of tens of seconds , corresponding to the putative low - frequency lorentzian in the psd , there is additional power in the soft band . to interpret this behaviour , we introduce a new spectral analysis technique , the ` covariance spectrum ' , to disentangle the contribution of the x - ray spectral components to variations on different time - scales . we use this technique to show that the disc blackbody component varies on all time - scales , but varies more , relative to the power - law , on longer time - scales . this behaviour explains the additional long - term variability seen in the soft band . comparison of the blackbody and iron line normalisations seen in the covariance spectra in gx 339 - 4 implies that the short - term blackbody variations are driven by thermal reprocessing of the power - law continuum absorbed by the disc . however , since the amplitude of variable reflection is the same on long and short time - scales , we rule out reprocessing as the cause of the enhanced disc variability on long time - scales . therefore we conclude that the long - time - scale blackbody variations are caused by instabilities in the disc itself , in contrast to the stable discs seen in bhxrb soft states . our results provide the first observational evidence that the low - frequency lorentzian feature present in the psd is produced by the accretion disc . [ firstpage ] . And you have already written the first three sentences of the full article: x - ray spectra of bhxrbs show evidence for a two - phase structure to the accretion flow , an optically thick , geometrically thin accretion disc @xcite giving rise to a blackbody component in the x - ray spectrum , and a hot optically - thin component , modelled as a power law . the relative strengths of these two components define the appearance of different ` states ' ( e.g. @xcite ) . in the hard state , which we focus on in this paper , the power - law emission dominates the total luminosity .. Please generate the next two sentences of the article

it has been suggested that the power - law is produced by an inner , optically - thin advection dominated accretion flow ( adaf ) ( e.g. @xcite ) , which replaces the inner optically thick disc at low accretion rates , and extends down to the innermost stable circular orbit ( isco ) . this implies that the optically thick disc is truncated at some transition radius .

Suppose that you have an abstract for a scientific paper: the main features of four - neutrino 3 + 1 and 2 + 2 mixing schemes are reviewed , after a discussion on the necessity of at least four massive neutrinos if the solar , atmospheric and lsnd anomalies are due to neutrino oscillations . . And you have already written the first three sentences of the full article: solar and atmospheric neutrino experiments have observed for a long time anomalies that are commonly interpreted as evidences in favor of neutrino oscillations with mass squared differences @xmath0 respectively ( see refs.@xcite ) . more recently , the accelerator lsnd experiment has reported the observation of @xmath1 and @xmath2 appearance @xcite with a mass - squared difference @xmath3 the lsnd evidence in favor of neutrino oscillations has not been confirmed by other experiments , but it has not been excluded either . awaiting an independent check of the lsnd result , that will probably come soon from the miniboone experiment @xcite , it is interesting to consider the possibility that the results of solar , atmospheric and lsnd experiments are due to neutrino oscillations . in this case , the existence of the three mass - squared differences ( [ dm2sun])([dm2lsnd ] ) with different scales implies that there are at least four massive neutrinos ( three massive neutrinos are not enough because the three @xmath4 s have different scales and do not add up to zero ) . since the mass - squared differences ( [ dm2sun])([dm2lsnd ] ) have been obtained by analyzing separately the data of each type of experiment ( solar , atmospheric and lsnd ) in terms of two - neutrino mixing , it is legitimate to ask if three different mass squared are really necessary to fit the data .. Please generate the next two sentences of the article

the answer is `` yes '' , as explained in section [ three ] . although the precise measurement of the invisible width of the @xmath5 boson has determined that there are only three active flavor neutrinos , @xmath6 , @xmath7 , @xmath8 , the possible existence of at least four massive neutrinos is not a problem , because in general flavor neutrinos are not mass eigenstates , _

Suppose that you have an abstract for a scientific paper: the deuterium abundance evaluation in the direction of capella has for a long time been used as a reference for the local interstellar medium ( ism ) within our galaxy . we show here that broad and weak h@xmath0i components could be present on the capella line of sight , leading to a large new additional systematic uncertainty on the @xmath1(h@xmath0i ) evaluation . the d / h ratio toward capella is found to be equal to @xmath2 with almost identical @xmath3 for all the fits ( this range includes only the systematic error ; the 2 @xmath4 statistical one is almost negligible in comparison ) . it is concluded that d / h evaluations over h@xmath0i column densities below @xmath5 ( even perhaps below @xmath6 if demonstrated by additional observations ) may present larger uncertainties than previously anticipated . it is mentionned that the d / o ratio might be a better tracer for d@xmath0i variations in the ism as recently measured by the far ultraviolet spectroscopic explorer ( _ fuse _ ) . . And you have already written the first three sentences of the full article: deuterium is understood to be only produced in significant amount during primordial big bang nucleosynthesis ( bbn ) and thoroughly destroyed in stellar interiors . deuterium is thus a key element in cosmology and in galactic chemical evolution ( see e.g. audouze & tinsley 1976 ) . indeed , its primordial abundance is the best tracer of the baryonic density parameter of the universe @xmath7 , and the decrease of its abundance during the galactic evolution should trace the amount of star formation ( among other astrophysical interests ) . in the galactic ism , d / h measurements made toward hot stars have suggested variations : imaps observations toward @xmath8 ori led to a low value ( jenkins _ et al . _. Please generate the next two sentences of the article

1999 ) , confirming the previous analysis by laurent _ et al . _ ( 1979 ) from _ copernicus _ observations , while toward @xmath9 vel they led to a high value ( sonneborn _ et al . _ 2000

Suppose that you have an abstract for a scientific paper: a graph is called @xmath0-planar if it can be drawn on the plane so that each edge is crossed by at most one other edge . in this paper , we establish a local property of @xmath0-planar graphs which describes the structure in the neighborhood of small vertices ( i.e. vertices of degree no more than seven ) . meanwhile , some new classes of light graphs in @xmath0-planar graphs with the bounded degree are found . therefore , two open problems presented by fabrici and madaras [ the structure of 1-planar graphs , discrete mathematics , 307 , ( 2007 ) , 854865 ] are solved . furthermore , we prove that each @xmath0-planar graph @xmath1 with maximum degree @xmath2 is acyclically edge @xmath3-choosable where @xmath4 . _ keywords _ : @xmath0-planar graph ; light graph ; acyclic edge coloring . please cite this published article as : _ x. zhang , g. liu , j .- l . wu . structural properties of 1-planar graphs and an application to acyclic edge coloring . scientia sinica mathematica , 2010 , 40 , 10251032_. . And you have already written the first three sentences of the full article: in this paper , all graphs considered are finite , simple and undirected . we use @xmath5 , @xmath6 , @xmath7 and @xmath2 to denote the vertex set , the edge set , the minimum degree and the maximum degree of a graph @xmath1 , respectively . denote @xmath8 and @xmath9 . let @xmath10 ( or @xmath11 for simple ) denote the degree of vertex @xmath12 .. Please generate the next two sentences of the article

a @xmath13- , @xmath14- and @xmath15-@xmath16 is a vertex of degree @xmath13 , at least @xmath13 and at most @xmath13 , respectively . any undefined notation follows that of bondy and murty @xcite .

Suppose that you have an abstract for a scientific paper: we present a proposal for a gravitational wave detector , based on the excitation of an electromagnetic mode in a resonance cavity . the mode is excited due to the interaction between a large amplitude electromagnetic mode and a quasi - monochromatic gravitational wave . the minimum metric perturbation needed for detection is estimated to the order @xmath0 using current data on superconducting niobium cavities . using this value together with different standard models predicting the occurrence of merging neutron star or black hole binaries , the corresponding detection rate is estimated to 120 events per year , with a ` table top ' cavity of a few meters length . [ [ section ] ] during the last decades the quest for detecting gravitational waves has intensified . the efforts have been inspired by the indirect evidence for gravitational radiation @xcite , advances in technology and the prospects of obtaining new useful astrophysical information through the development of gravitational wave astronomy @xcite . a number of ambitious detector projects are already in operation or being built all over the world , for example ligo and allegro in usa , virgo , auriga and geo 600 in europe , tama 300 in japan , aigo and niobe in australia @xcite . furthermore , there are well developed plans to use space based gravitational wave detectors , i.e. , the lisa project @xcite . the detection mechanisms are basically of a mechanical nature in the cases above , but there have also been several proposals for electromagnetic detection mechanisms @xcite . in the present paper we will investigate a detection mechanism based on the interaction of electromagnetic modes and gravitational radiation in a cavity with highly conducting walls . the main feature of our proposed gravitational wave detector is that it supports two electromagnetic eigenmodes with nearby eigenfrequencies , a possibility that has previously been discussed in refs . @xcite . if one eigenmode is excited initially ( called the.... And you have already written the first three sentences of the full article: 99 taylor j h 1994 _ rev . mod . phys . _ * 66 * 711 url ` http://www.ligo.caltech.edu/ ` ; url ` http://www.virgo.infn.it/ ` ; + url ` http://www.geo600.uni-hannover.de/ ` ; url ` http://tamago.mtk.nao.ac.jp/ ` ; url ` http://www.gravity.uwa.edu.au/aigo/aigo.html ` ; url ` http://sam.phys.lsu.edu/ ` ; url ` http://www.auriga.lnl.infn.it/ ` ; url ` http://www.gravity.uwa.edu.au/bar/bar.html ` braginski v b and menskii m b 1971 _ zh . pisma _ * 13 * 585 [ 1971 _ jetp lett . _. Please generate the next two sentences of the article

* 13 * 417 ] ; lupanov g a 1967 _ zh . eksp . fiz . _ * 52 * 118 [ 1967 _ sov .

Suppose that you have an abstract for a scientific paper: we present results from a careful and detailed analysis of the structural and dynamical properties of a sample of 29 disc - like objects identified at @xmath0 in three ap3m - sph fully consistent cosmological simulations . these simulations are realizations of a cdm hierarchical model , where an _ inefficient _ schmidt law - like algorithm to model the stellar formation process has been implemented . we focus on properties that can be constrained with available data from observations of spiral galaxies , namely , the bulge and disc structural parameters and the rotation curves . comparison with data from broeils ( 1992 ) , de jong ( 1996 ) and courteau ( 1996 , 1997 ) gives satisfactory agreement , in contrast with previous findings using other codes . this suggests that the stellar formation implementation we have used has succeeded in forming compact bulges that stabilize disc - like structures in the violent phases of their assembly , while in the quiescent phases the gas has cooled and collapsed according with the fall & efstathiou standard model of disc formation . galaxies : evolution galaxies : formation galaxies : structure galaxies : spiral hydrodynamics methods : numerical cosmology : theory dark matter . And you have already written the first three sentences of the full article: understanding how galaxies form and evolve into the objects we observe today remains one of the most fundamental quest of astrophysical research . even if the field is still at its beginnings , the use of numerical approaches to study how galaxies are assembled in a cosmological hierarchical scenario from primordial fluctuations , seems promising . the main advantage of these approaches ( namely hydrodynamical simulations ) is that physics is introduced at a most general level , and the dynamical processes relevant to galaxy assembly ( i.e. , collapse , gas infall , interactions , mergers , instabilities ... ) emerge naturally , rather than by assumption , and can be followed in detail .. Please generate the next two sentences of the article

only the star forming processes need to be modelled . these considerations emphasize the interest of hydrodynamical simulations as an outstanding working tool to learn about galaxy formation and evolution from primordial fluctuations .

Suppose that you have an abstract for a scientific paper: it is demonstrated that measurements of positions of atoms scattered from a quasi - condensate in a raman process provide information on the temperature of the parent cloud . in particular , the widths of the density and second order correlation functions are sensitive to the phase fluctuations induced by non - zero temperature of the quasi - condensate . it is also shown how these widths evolve during expansion of the cloud of scattered atoms . these results are useful for planning future raman scattering experiments and indicate the degree of spatial resolution of atom - position measurements necessary to detect the temperature dependence of the quasi - condensate . . And you have already written the first three sentences of the full article: atoms scattered out of bose - einstein condensates can be an object of benchmark tests of various quantum - mechanical models . a prominent example is a collision of two counter - propagating condensates @xcite . during the collision , which takes place at super - sonic velocity , atoms are scattered into initially empty modes , and description of such process requires fully quantum treatment .. Please generate the next two sentences of the article

this can be done semi - analytically in the bogoliubov approximation @xcite or numerically in more general cases @xcite . the analysis reveals strong correlations between the scattered atoms @xcite and sub - poissonian fluctuations of the opposite - momentum atom counts @xcite .

Suppose that you have an abstract for a scientific paper: recent x - ray observations have been used to demonstrate that the cluster gas mass - temperature relation is steeper than theoretical self - similar predictions drawn from numerical simulations that consider the evolution of the cluster gas through the effects of gravity and shock heating alone . one possible explanation for this is that the gas mass fraction is not constant across clusters of different temperature , as is usually assumed . observationally , however , there is no compelling evidence for gas mass fraction variation , especially in the case of hot clusters . seeking an alternative physical explanation for the observed trends , we investigate the role in the cluster gas mass - temperature relation of the preheating of the intracluster medium by some arbitrary source for clusters with emission - weighted mean temperatures of @xmath0 kev . making use of the physically - motivated , analytic models developed in 2002 by babul and coworkers , we find that preheating does , indeed , lead to a steeper relation . this is in agreement with previous theoretical studies on the relation . however , in apparent conflict with these studies , we argue that a `` high '' level of entropy injection is required to match observations . in particular , an entropy floor of @xmath1 kev @xmath2 is required . we also present a new test , namely , the study of the relation within different fixed radii . this allows one to indirectly probe the density profiles of clusters , since it samples different fractions of the virial radius for clusters of different temperature . this test also confirms that a high level of preheating is required to match observations . . And you have already written the first three sentences of the full article: analytic models and numerical simulations of clusters of galaxies have been used to predict the existence of scaling relations between various observable quantities , such as the well - known luminosity ( @xmath3 ) - temperature ( @xmath4 ) and mass ( @xmath5 ) - temperature relations , where and , respectively . however , it is now fairly well established that x - ray properties of clusters do not scale in such a fashion . most notable of these is the relationship , which is observed to be much steeper than predicted , ( e.g. , markevitch 1998 ; allen & fabian 1998 ; arnaud & evrard 1999 ) . considerable effort has recently been directed towards explaining why the observed relations deviate from their predicted scalings ( e.g. , tozzi & norman 2001 ; dav et al .. Please generate the next two sentences of the article

2001 ; babul et al . 2002 , hereafter bblp02 ) .

Suppose that you have an abstract for a scientific paper: we study equivalence relation of the set of triangles generated by similarity and operation on a triangle to get a new one by joining division points of three edges with the same ratio . using the moduli space of similarity classes of triangles introduced by nakamura and oguiso , we give characterization of equivalent triangles in terms of circles of apollonius ( or hyperbolic pencil of circles ) and properties of special equivalent triangles . we also study rationality problem and constructibility problem . 2010 _ mathematics subject classification _ : 51m04 . . And you have already written the first three sentences of the full article: we study elementary geometric operations on triangles defined as follows . let @xmath0 be a triangle , and @xmath1 be a real number . let @xmath2 , and @xmath3 be division points of the edges @xmath4 , and @xmath5 by @xmath6 respectively , namely , @xmath7 let @xmath8 ( @xmath9 or @xmath10 ) be the intersection of the lines @xmath11 and @xmath12 ( @xmath12 and @xmath13 or @xmath13 and @xmath11 respectively ) . define _ equisection operators _ @xmath14 and @xmath15 , where @xmath15 can be defined when @xmath16 , by @xmath17 the operators @xmath14 have been studied in articles such as @xcite , _ et .. Please generate the next two sentences of the article

al . _ ] 0.4 cm ] in this note we study the equivalence relation ( denoted by @xmath18 ) of the set of triangles ( denoted by @xmath19 ) generated by similarity and @xmath20 , which we shall call _ equisectional equivalence_. the equivalence relation generated by similarity and @xmath21 shall be called _ rational equisectional equivalence _ and denoted by @xmath22 . we say two triangles @xmath23 and @xmath24 are _ equisectionally equivalent _ ( or _ rational equisectionally equivalent _ ) if @xmath25 ( or @xmath26 respectively ) .

Suppose that you have an abstract for a scientific paper: we present _ spitzer _ irac imaging of the large - scale jet in the quasar pks 1136@xmath0135 at wavelengths of 3.6 and @xmath1 , combined with previous _ vla _ , _ hst _ , and _ chandra _ observations . we clearly detect infrared emission from the jet , resulting in the most detailed multifrequency data among the jets in lobe - dominated quasars . the spectral energy distributions of the jet knots have significant variations along the jet , like the archetypal jet in 3c 273 . the infrared measurements with irac are consistent with the previous idea that the jet has two spectral components , namely ( 1 ) the low - energy synchrotron spectrum extending from radio to infrared , and ( 2 ) the high - energy component responsible for the x - ray flux . the optical fluxes may be a mixture of the two components . we consider three radiation models for the high - energy component : inverse compton scattering of cosmic microwave background ( cmb ) photons by radio - emitting electrons in a highly relativistic jet , synchrotron radiation by a second distinct electron population , and synchrotron radiation by ultra high energy protons . each hypothesis leads to important insights into and constraints on particle acceleration in the jet , as well as the basic physical properties of the jet such as bulk velocity , transporting power , and particle contents . . And you have already written the first three sentences of the full article: over the last decade , optical and x - ray observations made with the _ hubble space telescope _ ( e.g. , * ? ? ? * ; * ? ? ? * ) and the _ chandra _ x - ray observatory ( e.g. , * ? ? ? * ) have produced exquisite images of extragalactic kiloparsec - scale jets , completely changing our understanding of their properties .. Please generate the next two sentences of the article

currently , more than 70 ( 30 ) extragalactic jets and hotspots are known in the x - ray ( optical ) ; ] all but the few brightest jets were discovered by _ ( _ hst _ ) . the origin of the broad - band spectral energy distributions ( seds ) of large - scale quasar jets , constructed using _ hst _ and

Suppose that you have an abstract for a scientific paper: ccd photometric observations in @xmath0 colors and spectroscopic observations of the newly discovered eclipsing binary gsc 2314 - 0530 ( nsvs 6550671 ) with dme components and very short period of @xmath1 days are presented . the simultaneous light - curve solution and radial velocity solution allows to determine the global parameters of gsc 2314 - 0530 : @xmath2 k ; @xmath3 k ; @xmath4 m@xmath5 ; @xmath6 m@xmath5 ; @xmath7 r@xmath5 ; @xmath8 r@xmath5 ; @xmath9 l@xmath5 ; @xmath10 l@xmath5 ; @xmath11 ; @xmath12 r@xmath5 ; @xmath13 pc . the chromospheric activity of its components is revealed by strong emission in the h@xmath14 line ( with mean @xmath15 ) and observed several flares . empirical relations mass@xmath16 , mass radius and mass temperature are derived on the basis of the parameters of known binaries with low - mass dm components . [ firstpage ] binaries : eclipsing binaries : spectroscopic stars : activity stars : fundamental parameters stars : late - type stars : low - mass . And you have already written the first three sentences of the full article: although the m dwarfs are the most numerous stars in our galaxy , the mass , metalicity and age dependencies of their stellar luminosities and radii are poorly calibrated . the reason is the selection effect that plays against the detection of fainter and smaller stars . less than 20 binaries with low - mass dm components have empirically - determined masses , radii , luminosities and temperatures ( see section [ sec : global ] , table [ tab : stars ] ) . as a result. Please generate the next two sentences of the article

the mass - luminosity relation is determined by only a few low - mass stars . this deficiency hindered the development of the models for the cool dense atmospheres of the m dwarfs .

Suppose that you have an abstract for a scientific paper: a unified scheme for quantum measurement processes is formulated on the basis of micro - macro duality as a mathematical expression of the general idea of _ quantum - classical correspondence_. in this formulation , we can naturally accommodate the amplification processes necessary for magnifying quantum state changes at the microscopic end of the probe system into the macroscopically visible motion of the measuring pointer . its essence is exemplified and examined in the concrete model of the stern - gerlach experiment for spin measurement , where the helgason duality controlling the radon transform is seen to play essential roles . . And you have already written the first three sentences of the full article: in this paper , we present a unified description of a measurement process of quantum observables together with the amplification process associated with it . for this purpose , we recall the essence of micro - macro duality @xcite as a mathematical expression of the general idea of quantum - classical correspondence which plays crucial roles . in this context , we note that the ` boundary ' between the quantum and classical levels can be found in the notion of a sector , in terms of which we can understand , in a clear - cut manner , the mutual relations between the microscopic quantum world and the macroscopic classical levels . to define a sector , we classify representations and states of a c*-algebra @xmath0 of quantum observables according to the _ quasi - equivalence _. Please generate the next two sentences of the article

@xmath1 @xcite defined by the unitary equivalence of representations @xmath2 _ up to multiplicity _ , which is equivalent to the isomorphism of von neumann algebras @xmath3 of representatoins @xmath4 and @xmath5 . sector _ or a _ pure phase _ in the physical context is then defined by a quasi - equivalence class of _ factor _ representations and states corresponding to a von neumann algebra with a trivial centre , which is a minimal unit among quasi - equivalence classes .

Suppose that you have an abstract for a scientific paper: active peer - to - peer ( p2p ) worms present serious threats to the global internet by exploiting popular p2p applications to perform rapid topological self - propagation . active p2p worms pose more deadly threats than normal scanning worms because they do not exhibit easily detectable anomalies , thus many existing defenses are no longer effective . we propose an immunity system with _ phagocytes _ a small subset of elected p2p hosts that are immune with high probability and specialized in finding and `` eating '' worms in the p2p overlay . the phagocytes will monitor their managed p2p hosts connection patterns and traffic volume in an attempt to detect active p2p worm attacks . once detected , local isolation , alert propagation and software patching will take place for containment . the phagocytes further provide the access control and filtering mechanisms for communication establishment between the internal p2p overlay and the external hosts . we design a novel adaptive and interaction - based computational puzzle scheme at the phagocytes to restrain external worms attacking the p2p overlay , without influencing legitimate hosts experiences significantly . we implement a prototype system , and evaluate its performance based on realistic massive - scale p2p network traces . the evaluation results illustrate that our phagocytes are capable of achieving a total defense against active p2p worms . . And you have already written the first three sentences of the full article: the ability to gain control of a huge amount of internet hosts could be easily achieved by the exploitation of worms which self - propagate through popular internet applications and services . internet worms have already proven their capability of inflicting massive - scale disruption and damage to the internet infrastructure . these worms employ normal _ scanning _ as a strategy to find potential vulnerable targets , i.e. , they randomly select victims from the ip address space .. Please generate the next two sentences of the article

so far , there have been many existing schemes that are effective in detecting such scanning worms @xcite , e.g. , by capturing the scanning events @xcite or by passively detecting abnormal network traffic activities @xcite . in recent years , peer - to - peer ( p2p ) overlay applications have experienced an explosive growth , and now dominate large fractions of both the internet users and traffic volume @xcite ; thus , a new type of worms that leverage the popular p2p overlay applications , called _ p2p worms _ , pose a very serious threat to the internet @xcite .

Suppose that you have an abstract for a scientific paper: we investigate equatorial geodesics in the gravitational field of a rotating and deformed source described by the approximate hartle - thorne metric . in the case of massive particles , we derive within the same approximation analytic expressions for the orbital angular velocity , the specific angular momentum and energy , and the radii of marginally stable and marginally bound circular orbits . moreover , we calculate the orbital angular velocity and the radius of lightlike circular geodesics . we study numerically the frame dragging effect and the influence of the quadrupolar deformation of the source on the motion of test particles . we show that the effects originating from the rotation can be balanced by the effects due to the oblateness of the source . . And you have already written the first three sentences of the full article: in general , observed astrophysical objects are characterized by a non - spherically symmetric distribution of mass and by rotation . in many cases , like ordinary planets and satellites , it is possible to neglect the deviations from spherical symmetry and the frame dragging effect , so that the gravitational field can be described by the exterior schwarzschild solution . in fact , the three classical tests of general relativity make use of the schwarzschild spacetime in order to describe gravity within the solar system@xcite . in the case of strong gravitational fields , however , the deviation from spherical symmetry and the rotation become important and must be taken into account , at least to some extent .. Please generate the next two sentences of the article

the first metric describing the exterior field of a slowly rotating slightly deformed object was found by hartle and thorne@xcite in 1968 . alternative methods were proposed independently by fock and abdildin@xcite and sedrakyan and chubaryan@xcite . only recently , it was shown that in fact all these approaches are equivalent from a mathematical point of view@xcite . at the level of the interpretation of the parameters entering the metric used in each approach

Suppose that you have an abstract for a scientific paper: we develop a new method to measure source proper motions in microlensing events , which can partially overcome problems due to blending . it takes advantage of the fact that the source position is known precisely from the microlensing event itself . we apply this method to the event moa-2011-blg-262 , which has a short timescale @xmath0day , a companion mass ratio @xmath1 and a very high or high lens - source relative proper motion @xmath2 or @xmath3 ( for two possible models ) . these three characteristics imply that the lens could be a brown dwarf or a massive planet with a roughly earth - mass `` moon '' . the probability of such an interpretation would be greatly increased if it could be shown that the high lens - source relative proper motion was primarily due to the lens rather than the source . based on the long - term monitoring data of the galactic bulge from the optical gravitational lensing experiment ( ogle ) , we measure the source proper motion that is small , @xmath4 in a ( north , east ) galactic coordinate frame . these values are then important input into a bayesian analysis of the event presented in a companion paper by bennett et al . . And you have already written the first three sentences of the full article: lens - source relative proper motions @xmath5 are frequently measured in planetary microlensing events , but to date there are no published measurements of the source proper motion itself in these events ( @xmath6 ) . this may seem surprising at first sight because the source is almost always visible whereas the lens is typically invisible . in fact , however , @xmath7 is generally both more useful and easier to measure than @xmath6 .. Please generate the next two sentences of the article

source - lens proper motions can be measured essentially whenever there are significant finite - source effects in the event @xcite because the source - lens crossing time @xmath8 is directly measurable from the light curve , while the angular size of the source can be extracted from its dereddened color and magnitude @xcite , which in turn can be extracted by placing the source on an instrumental color - magnitude diagram @xcite . the most important application of @xmath7 is not the proper - motion itself , but rather that it immediately yields the einstein radius , @xmath9 where @xmath10 is the einstein timescale ( measurable from the event ) , @xmath11 is the lens mass , and @xmath12 is the lens - source relative parallax .

Suppose that you have an abstract for a scientific paper: a general framework for performing event - driven simulations of systems with semi - flexible or rigid bodies interacting under impulsive torques and forces is outlined . two different approaches are presented . in the first , the dynamics and interaction rules are derived from lagrangian mechanics in the presence of constraints . this approach is most suitable when the body is composed of relatively few point masses or is semi - flexible . in the second method , the equations of rigid bodies are used to derive explicit analytical expressions for the free evolution of arbitrary rigid molecules and to construct a simple scheme for computing interaction rules . efficient algorithms for the search for the times of interaction events are designed in this context , and the handling of missed interaction events is discussed . . And you have already written the first three sentences of the full article: there has been an increasing interest over the last decade in performing large - scale simulations of colloidal systems , proteins , micelles and other biological assemblies . simulating such systems , and the phenomena that take place in them , typically requires a description of dynamical events that occur over a wide range of time scales . nearly all simulations of such systems to date are based on following the microscopic time evolution of the system by integration of the classical equations of motion .. Please generate the next two sentences of the article

usually , due to the complexity of intermolecular interactions , this integration is carried out in a step - by - step numerical fashion producing a time ordered set of phase - space points ( a _ trajectory _ ) . this information can then be used to calculate thermodynamic properties , structural functions or transport coefficients .

Suppose that you have an abstract for a scientific paper: by solving a master equation in the sierpiski lattice and in a planar random - resistor network , we determine the scaling with size @xmath0 of the shot noise power @xmath1 due to elastic scattering in a fractal conductor . we find a power - law scaling @xmath2 , with an exponent depending on the fractal dimension @xmath3 and the anomalous diffusion exponent @xmath4 . this is the same scaling as the time - averaged current @xmath5 , which implies that the fano factor @xmath6 is scale independent . we obtain a value @xmath7 for anomalous diffusion that is the same as for normal diffusion , even if there is no smallest length scale below which the normal diffusion equation holds . the fact that @xmath8 remains fixed at @xmath9 as one crosses the percolation threshold in a random - resistor network may explain recent measurements of a doping - independent fano factor in a graphene flake . diffusion in a medium with a fractal dimension is characterized by an anomalous scaling with time @xmath10 of the root - mean - squared displacement @xmath11 . the usual scaling for integer dimensionality @xmath12 is @xmath13 , independent of @xmath12 . if the dimensionality @xmath3 is noninteger , however , an anomalous scaling @xmath14 with @xmath15 may appear . this anomaly was discovered in the early 1980 s @xcite and has since been studied extensively ( see refs . @xcite for reviews ) . intuitively , the slowing down of the diffusion can be understood as arising from the presence of obstacles at all length scales characteristic of a selfsimilar fractal geometry . a celebrated application of the theory of fractal diffusion is to the scaling of electrical conduction in random - resistor networks ( reviewed in refs.@xcite ) . according to ohm s law , the conductance @xmath16 should scale with the linear size @xmath0 of a @xmath12-dimensional network as @xmath17 . in a fractal dimension the scaling is modified to @xmath18 , depending both on the fractal dimensionality @xmath3 and on the anomalous.... And you have already written the first three sentences of the full article: here we present the method we used to calculate the fano factor for the tunnel exclusion process in the sierpiski lattice and in the random - resistor network . we follow the master equation approach of refs . the two - dimensionality of our networks requires a more elaborate bookkeeping , which we manage by means of the hamiltonian formalism of ref .. Please generate the next two sentences of the article

@xcite . we consider a network of @xmath53 sites , each of which is either empty or singly occupied .

Suppose that you have an abstract for a scientific paper: we introduce a scalable algorithm , mucca for multiclass node classification in weighted graphs . unlike previously proposed methods for the same task , mucca works in time linear in the number of nodes . our approach is based on a game - theoretic formulation of the problem in which the test labels are expressed as a nash equilibrium of a certain game . however , in order to achieve scalability , we find the equilibrium on a spanning tree of the original graph . experiments on real - world data reveal that mucca is much faster than its competitors while achieving a similar predictive performance . . And you have already written the first three sentences of the full article: classification of networked data is a quite attractive field with applications in computer vision , bioinformatics , spam detection and text categorization . in recent years networked data have become widespread due to the increasing importance of social networks and other web - related applications . this growing interest is pushing researchers to find scalable algorithms for important practical applications of these problems .. Please generate the next two sentences of the article

+ in this paper we focus our attention on a task called _ node classification _ , often studied in the semi - supervised setting @xcite . recently , different teams studied the problem from a theoretic point of view with interesting results . for example @xcite