共查询到20条相似文献,搜索用时 15 毫秒
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A. N. Elsukov 《Russian Physics Journal》1965,8(4):39-42
A rigorous solution is given for modes of TMnmo type. The complex resonant frequency n is expressed via a transcendental characteristic equation. Some particular cases are discussed.Read at the Third All-Union Conference on Ferrites, Leningrad, 23 October 1963. 相似文献
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Yu. D. Chernichenko 《Physics of Atomic Nuclei》2004,67(2):414-423
Within the relativistic quasipotential approach to quantum field theory, a method is developed for solving a finite-difference quasipotential equation for the case where a total quasipotential describing the interaction of two relativistic spinless particles of unequal masses is a superposition of a nonlocal separable and a local quasipotential. The cases are investigated where the local component of the total interaction—it is assumed to be known—either admits or does not admit the existence of bound states. This makes it possible to obtain an exact expression for the increment of the phase shift, to determine the conditions of the existence of bound states, and to give a generalization of the Levinson theorem. 相似文献
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Molecular-dynamics was used to investigate the structural changes occurring in a three-dimensional solid when the solid is
transferred from an amorphous into a crystalline state. Crystal cells of a new type — pentadecahedrons with five square lateral
faces and ten regular triangular faces at the vertices of a cell — were found for the first time in a computer experiment.
It is shown that a bistructure consisting of crystal cells of different types, including cells with five-fold symmetry axes,
are stable in the solid.
Fiz. Tverd. Tela (St. Petersburg) 40, 1919–1924 (October 1998) 相似文献
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V. I. Bukreev 《Doklady Physics》2002,47(12):880-882
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T. Ouisse 《The European Physical Journal B - Condensed Matter and Complex Systems》2001,22(4):415-420
The tunnelling lifetime of an electron lying in a p-type orbital localised at a given distance from a semiconductor or a metal is calculated by using Bardeen's method. It is
then shown that even in the absence of broad bands, the hole injection process from semiconductors and metals into polymers
should follow a Fowler-Nordheim dependence, provided that the current is not bulk-limited. In the semiconductor case, the
current can be expressed by a fully analytical formula, and by an approximate one in the case of a metal. It is demonstrated
that the effective Fowler-Nordheim barrier is not the mere difference between the metal work function or the semiconductor
electron affinity and the HOMO level of the polymer, but a simple function of both levels.
Received 6 April 2001 and Received in final form 29 May 2001 相似文献
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The existence of surface polaritons in a dielectric at a boundary with an ideal metal or superconductor in a static electric
field is predicted. The frequency regions in which polaritons exist are substantially different for opposite orientations
of the electric field, so that a change in the direction of the field signifies “switching on” or “switching off” of surface
polaritons with a fixed frequency.
Pis'ma Zh. éksp. Teor. Fiz. 68, No. 12, 876–880 (25 December 1998) 相似文献
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The scalar problem of the scattering of a wave from a nonlinear insertion lying in the interior of a waveguide is reduced by the incomplete Galerkin method to the boundary value problem for a Hamiltonian system. The cases in which this problem admits a solution in finite terms are indicated. Examples are given to illustrate specific phenomena due to the nonlinearity of the problem. 相似文献
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V. P. Glashchenko 《Technical Physics》2014,59(5):754-761
The conditions under which the nonuniform compensating field of the reflector of the mass-reflectron can be generated with an acceptable accuracy at the symmetry axis of the reflector and extrapolated to the radial neighborhood of the axial line are determined. The plots that illustrate the distribution of the calculated nonuniform field of the reflector, the possibilities for implementation, and errors of focusing with respect to time of flight in the radial neighborhood are presented. Analytical expressions for the calculation of the time of flight of ions in the reflector in which the field distribution is described using a power series and analytical expressions for the calculation of the field distribution in the reflector in which the time of flight is determined using a power series are derived. A method for the analytical calculation of the compensating nonuniform field of the reflector based on the given dependence of the time of flight in the absence of such a field is proposed using a solution to the Abel integral equation. The solution to this equation yields analytical expressions for the calculation of the compensating field of the reflector in mass-reflectrons that contain the zero-field drift space and regions of acceleration (deceleration) of ions with a uniform field. 相似文献
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We have investigated the transmission ability of a layered structure the central layer of which is made of a “left-handed” material (its refractive index is negative) and is separated by two air slabs from a “right-handed” dielectric medium that surrounds the structure. We consider tunneling of energy fluxes through the structure and determine conditions for the complete (reflectionless) transmission of the power of the incident wave through it. We show that this effect is resonant and is observed when the tangential component of the wave vector of the incident wave coincides with the longitudinal wave vector of one of waveguiding eigenmodes of the left-handed layer. 相似文献
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I. D. Remizov 《Russian Journal of Mathematical Physics》2012,19(3):360-372
The Cauchy problem for a class of diffusion equations in a Hilbert space is studied. It is proved that the Cauchy problem in well posed in the class of uniform limits of infinitely smooth bounded cylindrical functions on the Hilbert space, and the solution is presented in the form of the so-called Feynman formula, i.e., a limit of multiple integrals against a gaussian measure as the multiplicity tends to infinity. It is also proved that the solution of the Cauchy problem depends continuously on the diffusion coefficient. A process reducing an approximate solution of an infinite-dimensional diffusion equation to finding a multiple integral of a real function of finitely many real variables is indicated. 相似文献
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A phase transition of the first kind is a jump of a function, a phase transition of the second kind is a jump of its first derivative, a phase transition of the third kind, a jump of the second derivative. A phase transition from one statistic to another is very gradual, but finally it is as considerable as the phase transition of the first kind. However, we cannot introduce a clearly defined parameter to which this transition corresponds. This is due to the fact that the fluctuations near the critical point are huge, and this violates, in the vicinity of that point, the main law of equilibrium thermodynamics, which asserts that fluctuations are relatively small. The paper describes the transition in the supercritical fluid region of equilibrium thermodynamics from parastatistics to mixed statistics, in which the Boltzmann statistics is realized for long-living clusters. In economics this corresponds to a negative nominal credit rate. Examples of this non-standard situation are presented. 相似文献
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《Physics letters. A》1999,251(3):164-168
We derive an expression for the Pancharatnam phase for the entangled state of a single two-level atom interacting with a single electromagnetic field mode in an ideal cavity with the atom undergoing either a one- or a two-photon transition. It is shown that the Pancharatnam phase explicitly contains information about the statistics of the field and atomic coherence. 相似文献
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The problem of sound diffraction by a groove on a rigid surface in the presence of a grazing flow is considered. The input admittance of the groove is calculated, and its real part is shown to be negative. 相似文献
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Sinan Demir Vitaly Bychkov Sri Hari Ramakrishna Chalagalla 《Combustion Theory and Modelling》2017,21(6):997-1022
To reveal the inner mechanisms of a combustion accident in a coalmine, the key stages and characteristics of premixed flame front evolution such as the flame shapes, propagation speeds, acceleration rates, run-up distances and flame-generated velocity profiles are scrutinised. The theories of globally spherical, expanding flames and of finger-flame acceleration are combined into a general analytical formulation. Two-dimensional and cylindrical mining passages are studied, with noticeably stronger acceleration found in the cylindrical geometry. The entire acceleration scenario may promote the total burning rate by up to two orders of magnitude, to a near-sonic value. Starting with gaseous combustion, the analysis is subsequently extended to gaseous-dusty environments. Specifically, combustible dust (e.g. coal), inert dust (e.g. sand), and their combination are considered, and the influence of the size and concentration of the dust particles is quantified. In particular, small particles influence flame propagation more than large ones, and flame acceleration increases with the concentration of a combustible dust, until the concentration attains a certain limit. 相似文献
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Ya. V. Fominov 《JETP Letters》2008,86(11):732-736
The conductance of a junction between a normal metal and a superconductor having the symmetry proposed by Berezinskii is studied
theoretically. The main feature of this symmetry is the odd frequency dependence of the anomalous Green’s function, which
makes possible the s-wave triplet superconducting state (the Berezinskii superconductor). The Andreev reflection (which links
positive and negative energies) is sensitive to the energetic symmetry; as a result, the conductance of the junction involving
the Berezinskii superconductor is qualitatively different from the case of a conventional superconductor. Experimentally,
the obtained results can be employed to test the possibility of the Berezinskii superconductivity proposed for Na
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CoO2 and to identify the odd-ω component predicted for superconductor-ferromagnet systems. 相似文献