On the determination of the ZnAs$_2$ band structure parameters
On the determination of the ZnAs$_2$ band structure parameters
V.A. Morozova, S.F. Marenkin, 0.G. Koshelev
A method for taking into account light scattering in ZnAs$_2$ and obtaining the $\alpha^\parallel(h\nu)$ absorption spectrum was suggested. At the $E\parallel c$ polarization, the absorption edge was shown to be determined by indirect and direct allowed transitions with the energy difference 64 meV between them, which involved exciton states. For both transitions, in the temperature range $80 \div 300$ K, the forbidden band width was determined.
Show AbstractWhy does the Meissner effect arise?
Why does the Meissner effect arise?
N.B. Brandt, G.A. Mironova, V.V. Rzhevskii
A possible experiment that would allow one to determine the necessary and sufficient conditions for the Meissner effect to arise in classical superconductors is described.
Show AbstractX-ray diffraction study of interatomic correlations in alloys with components having close atomic numbers (Cu-Zn and Cu-Ni)
X-ray diffraction study of interatomic correlations in alloys with components having close atomic numbers (Cu-Zn and Cu-Ni)
A.A. Katsnelson, V.M. Silonov, T.V. Skorobogatova, O.V. Kris'ko
By the method of X-ray diffuse scattering, a short-range order in Cu-Zn alloys and short-range stratification in Cu-Ni alloys have been established.
Show AbstractInverse reluctance in granulated ferromagnetic alloys
Inverse reluctance in granulated ferromagnetic alloys
A.B. Granovskii$^1$, V.A. Kovalev$^1$, J.-P. Clerc$^2$
A model describing reluctance of granulated alloys with allowance made for the effect of $d$-electrons on current transport is proposed. Within the framework of this model, the presence of positive reluctance for a number of granulated alloys {Co-Cu, Co-Ag, etc.) and multilayers {Fe/Cr, Co/Cu, Fe/Cu, etc.) is explained.
Show AbstractSeismotectonic strain of lithosphere in the Aegean region
Seismotectonic strain of lithosphere in the Aegean region
E.V. Voronina, A.V. Lyusina
Seismotectonic strain rate tensors, the main and effective strain rates for the lithosphere of the Aegean region have been computed. The orientation of the compressive and tensile strain axes has been determined. The relationship between possible failure of the medium and the effective strain rate has been established for the first time. Observation of strong 1991-1997 earthquakes has shown that regions of high seismic hazard are those where the strain rates are at their minimum.
Show AbstractStatistical properties of fixed points of dynamic systems
Statistical properties of fixed points of dynamic systems
P.V. Elyutin
A relative prevalence of fixed points of various classes in the phase plane for autonomous systems of the general form is studied. It is shown that saddlepoints are most frequently met, foci are more seldom, and knots are even more seldom.
Show AbstractStudying physical processes in nonperiodic highly heterogeneous media
Studying physical processes in nonperiodic highly heterogeneous media
G.N. Medvedev, B.I. Morgunov
Mathematical models of electrodynamical and thermomechanical processes in highly heterogeneous nonperiodic media have been considered. An iterative procedure for determining the asymptotic expansion coefficients of solutions of electrodynamics and thermoelasticity equations has been described.
Show AbstractExcitation of nonlinear waves by finite-amplitude vibrations of a sphere in a linearly deformable medium
Excitation of nonlinear waves by finite-amplitude vibrations of a sphere in a linearly deformable medium
Wang Ning, 0.V. Rudenko
The wave profile shape and the spectral composition of a wave emitted into a medium by an oscillating spherically symmetrical surface are calculated. It is shown that the local distortions that occur upon the transition from the sphere vibrational motion to the medium wave motion are induced by the boundary nonlinearity.
Show AbstractПодводные многочастотные акустические излучатели малых волновых размеров на основе неоднородных активных дискретных структур
Подводные многочастотные акустические излучатели малых волновых размеров на основе неоднородных активных дискретных структур
П.Н. Кравчун
Исследуются многочастотные гидроакустические излучатели, построенные на основе неоднородных дискретных структур типа низкочастотного активного электромеханическоrо фильтра. Предложен метод расчета подобных излучателей, основанный на алгебре кумулянтов дискретной структуры, определены необходимые условия оптимальной электрической фазировки активных звеньев структуры. Рассмотрен частный случай периодической структуры. Приведены результаты морского эксперимента для трехчастотного излучателя.
Show AbstractЭквивалентность усреднения вдоль прямой линии и усреднения по объему для многопараметрических случайных полей
Эквивалентность усреднения вдоль прямой линии и усреднения по объему для многопараметрических случайных полей
А.Г. Вологдин, В.Д. Гусев
Доказано, что возможно получить пространственные статистические характеристики случайно-неоднородных сред путем усреднения вдоль прямой линии произвольного направления вместо усреднения по объему. Тем самым найдено новое решение проблемы пространственной эргодичности. Показано, что только при постоянной скорости перемещения среды измерение временных средних позволяет находить пространственные статистические характеристики. Результаты представляют интерес для обработки натурных данных, полученных при распространении волн разной природы (и частоты) в различных слоях атмосферы, а также в океане.
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