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1.
《Physics letters. A》1986,117(9):433-435
A recent claim by De Muynck that the Bell inequalities are completely irrelevant to the locality problem is opposed. The various ways in which the inequalities are relevant and not relevant are briefly discussed.  相似文献   

2.
Modification of the Fock method is used to look systematically for the complexes of energy and momentum which are conserved as a consequence of the vacuum field equations of the second order (real and complex scalar field, real vector field, symmetric tensor field of the linearized and non-linear Einstein theory). In contrast to Fock's results for fields described by equations of the first order, the complexes are not defined uniquely. The non-uniquenesses are eliminated by supplementary conditions.This paper is based on a diploma thesis worked out at the Department of Theoretical Physics, Faculty of Mathematics and Physics, Charles University.  相似文献   

3.
《Physica A》1988,149(3):551-560
We have derived the Burnett-order transport equations by applying the Hilbert expansion to the steady BGK equation. The pressure tensor and heat flux vector are computed for potentials of the form r−μ. The calculated transport coefficients are compared with those obtained by means of the Chapman-Enskog expansion.  相似文献   

4.
《Nuclear Physics A》1986,459(2):286-316
The structures of sd-shell nuclei with open shells are studied by a method which enables us to investigate properties of excited states and bulk properties of the nucleus at the same time. An effective interaction including three-body force with 15 strength parameters is used. The bulk properties of sd-shell nuclei with mass number 18–22 and 34–38 are studied. The calculated results for bulk properties reproduce experimental values fairly well, but the results for excitation energies are poor. Some of the electromagnetic properties, moments and transition probabilities have close resemblance to those obtained by usual shell model calculations using a realisitc interaction or an effective interaction. The defects of this method and a way to improve our method are discussed.  相似文献   

5.
A complete account of the Hamiltonian approach to the coupled perturbations of the Reissner-Nordström black hole, initiated by Moncrief, is given. All Hamiltonian equations are expressed explicitly in suitable forms; the metric and electromagnetic field perturbations are found in terms of Moncrief's gauge invariant canonical variables in the Regge-Wheeler gauge. The basic (both tetrad and coordinate) gauge invariant scalars occurring in the perturbation studies based on the Newman-Penrose formalism are then related to Moncrief's variables. The strikingly simple relations obtained enable us to show that the fundamental pair of decoupled equations, derived recently within the Newman-Penrose formalism by Chandrasekhar, can be cast into gauge invariant form, and that it can be obtained from Moncrief's formalism.It is demonstrated how the fundamental equations, supplemented by another combination of the Newman — Penrose equations, generalize the Bardeen-Press equations for uncoupled electromagnetic and gravitational perturbations of the Schwarzschild black hole.The odd and the even parityl=1 perturbations are also considered in detail. In the Appendix the relations to Zerilli's work on coupled perturbations of the Reissner-Nordström black hole are given.  相似文献   

6.
The generalized path expansion scheme is defined for path integration in phase-space. Within this framework we study the semiclassical limits to the propagator, both in the momentum and the coordinate representations. It is shown that the role played by the Morse operator in the Lagrangian formulation of the path integral method is taken by another differential operator of the Dirac type. The relevant properties of this operator are discussed. The semiclassical approximations are obtained by extending the results of catastrophe theory for the asymptotic evaluation of finite-dimensional integrals to the domain of path integration. Various forms of the uniform semiclassical approximations are obtained. Their validity and applicability are discussed. The method is illustrated by a solution of a simple example in which nongeneric catastrophe occurs.  相似文献   

7.
In this paper, we provide properties—which are, to the best of our knowledge, new—of the zeros of the polynomials belonging to the Askey scheme. These findings include Diophantine relations satisfied by these zeros when the parameters characterizing these polynomials are appropriately restricted.  相似文献   

8.
The asymptotical properties of a Markov system with discrete states are derived from the Master equation by using the quadratic approximate form of entropy.In particular, symmetry relations equivalent to the Onsager reciprocal relations are established for time reversal invariant systems.  相似文献   

9.
Form factors are calculated in the point form of relativistic quantum mechanics for the lowest energy states of a system made of two scalar particles interacting via the exchange of a massless boson. They are compared to the exact results obtained by using solutions of the Bethe-Salpeter equation which are well known in this case (Wick-Cutkosky model). The relevance of the comparison is examined by considering other relativistic quantum-mechanics approaches where results are known or have been obtained recently. Deficiencies of the point-form approach together with the single-particle current are emphasized. They point to quite sizeable contributions of two-body currents. These ones are required to fulfil current conservation in any case and to reproduce the high momentum transfer behaviour expected from the Born amplitude. Received: 11 July 2001 / Accepted: 12 February 2002  相似文献   

10.
热控涂层光学性能退化模型研究   总被引:2,自引:0,他引:2       下载免费PDF全文
在实验研究成果的基础上,给出了热控涂层在空间辐照作用下的退化模型,接着用渐变折射率的概念对复折射率材料热控涂层的光学性能进行了分析,得到了退化前后热控涂层光学性能变化的表达式,最后对热控涂层光学性能退化模型的应用进行了探讨. 关键词: 热控涂层 渐变折射率 辐照 退化  相似文献   

11.
The disagreement between the experimental and calculated positions of the first convergence zone are known from many publications. The most probable cause for such a disagreement, namely, the incorrect specification of the input data for the calculations, is considered. The lack of simultaneity between the hydrological surveys of the region and the acoustic experiments is emphasized. The experimental data obtained by the author in five ocean regions are presented. These data characterize the diurnal variability of the distance from the source to the nearest boundary of the convergence zone. The relations proposed by different researchers for calculating the sound speed from the temperature, salinity, and hydrostatic pressure are analyzed. It is shown that these relations lead to a substantial difference in the estimated depth dependence of the hydrostatic gradient of the sound speed. The position of the first convergence zone is calculated for the propagation conditions determined by vertical temperature and salinity profiles with the subsequent recalculation of these profiles into sound speed profiles by using eight different formulas known from the literature. It is shown that different formulas lead to different values of the distance to the first zone; this difference is substantially greater than that between the calculations and experiment. The necessity of improving the recalculation relations in view of the experimental data on sound propagation in natural oceanic waveguides, including the data on the actual positions of the convergence zones, is emphasized.  相似文献   

12.
Effects of the three-nucleon forces on the triton binding energy are investigated using different models for which the xN scattering amplitudes for the off-mass-shell pions are extrapolated from the on-mass-shell data. In the independent model potential, the threenucleon forces are constructed using the chiral symmetry through partial conservation of the axial current vectors and current algebra. On the other hand, the three-nucleon forces in the dependent model potential are derived from an effective Lagrangian which is constrained by chiral and gauge symmetry. The effect of the long range 2π and the repulsive ap-exchange three-nucleon forces on the triton binding energy are investigated. The bound state triton binding energies are then calculated by solving the Faddeev equations with a Hamiltonian including the three-nucleon forces, using different nucleon-nucleon interactions. The pionic form factors are considered with different sets of the form factor cutoff,parameter Λ. The 2π-exchange forces with S- and P-wave amplitudes are found to overbind the triton binding energy by about 0.4~Y 1.6 MeV. However, xp-exchange forces are found to reduce the 2π exchange forces by about 18% of its contribution, to the triton binding energy.  相似文献   

13.
Recent laboratory measurements of acoustic backscattering by individual benthic shells have isolated the edge-diffracted echo from echoes due to the surface of the main body of the shell. The data indicate that the echo near broadside incidence is generally the strongest for all orientations and is due principally to the surface of the main body. At angles well away from broadside, the echo levels are lower and are due primarily to the diffraction from the edge of the shell. The decrease in echo levels from broadside incidence to well off broadside is shown to be reasonably consistent with the decrease in acoustic backscattering from normal incidence to well off normal incidence by a shell-covered seafloor. The results suggest the importance of the edge of the shell in off-normal-incidence backscattering by a shell-covered seafloor. Furthermore, when considering bistatic diffraction by edges, there are implications that the edge of the shell (lying on the seafloor) can cause significant scattering in many directions, including at subcritical angles.  相似文献   

14.
The anatomy and functions of the blood and lymph vessels of human skin are described. Variation in these due to site, ageing and events during life consequent to exposure to a threatening environment are emphasised. Gradual atrophy and greater heterogeneity are features of ageing. Responses to injury and repair are complex and the interaction of mechanical signals distorting skin cells with numerous chemical signals are referred to. The lymphatics are part of an immunosurveillance system to monitor skin barrier penetration. The review attempts to draw attention to key recent advances in our understanding of the cytokine and growth factor production of the skin in the context of previous mainly physiological reviews especially influenced by 50 years of clinical practice as a dermatologist with an eye on both the skin and the fields of microcirculation and lymphology.  相似文献   

15.
弯曲振动引致的过渡态的混沌   总被引:1,自引:0,他引:1  
从单摆运动的特征出发 ,指出分子的过渡态 (包括解离时的态 ) ,如分子内弯曲振动引致结构变化的过渡态 ,必然伴随着混沌现象 ,而且和Chirikov的多重共振会导致混沌的观点有关 .并以从HCN、HNC和其非局域态的高激发振动态的能级拟合得到的弯曲模式的性质说明这个观点 .最后 ,提出一个处理弯曲振动引致的过渡态的混沌的物理模型 .  相似文献   

16.
The post-Newtonian effects of the rotation of the central body on the variation of celestial orbital elements are studied according to the post-Newtonian metric theory. The variation of celestial orbital elements caused by the rotation of the central body in three gravitational theories of Einstein, Brans-Dicke and Nordtvedt is obtained by using the method of general perturbation. The resulting effects are the periodic variation of inclination, eccentricity and mean anomaly; the periodic and secular variation of longitudes of periastron and ascending node and mean longitudes of epoch, but the semimajor axis remains unperturbed (no variation). In addition, the obtained theoretical results are applied to the calculation of the post-Newtonian effect of the rotation of the sun on the variation of the orbital elements of planets in solar system. The numerical results are given in nble 1. Finally, the obtained results are discussed and compared with other theories.  相似文献   

17.
Symmetries of spacetime manifolds which are given by Killing vectors are compared with the symmetries of a Lagrangian constructed from a Weyl re-scaled metric used in discussing disorder operators in Gauge theories. We find the point generators of the one parameter Lie groups of transformations that leave invariant the action integral corresponding to the Lagrangian (Noether symmetries). It is shown that the Noether symmetries obtained by considering the Lagrangian provide additional symmetries which are not provided by the Killing vectors. New conservation law/s are determined.  相似文献   

18.
Terufumi Yokota 《Physica A》2008,387(14):3495-3502
Equations for the spin glass order in the Ising spin glass model on the Bethe-like lattices with and without small loops are studied. For each lattice, equations are obtained by using and not using the replica method. Within the replica symmetric approximation, equations obtained by the two ways are shown to be identical. To see the effects of the small loops and the replica symmetry breaking, a spin glass order parameter is investigated as a function of the connectivity of the lattices close to the transition temperature. Replica symmetry breaking is enhanced by the existence of small loops.  相似文献   

19.
肖伯钧 《大学物理》2003,22(5):22-24
讨论了银道面内的引力场强分布和太阳在银河系中所受引力与到银心距离r的关系,指出引力场强g并不是与r的平方成反比,这是由于银河系的大小和形状不能忽略造成的.强调了万有引力定律的适用条件.  相似文献   

20.
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