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981.
A waveguide with a rectangular cross section of size and orientation slowly changing along the length of the waveguide is considered. Methods of the canonical perturbation theory are used to describe the ray dynamics in the waveguide. As the size and orientation of the cross section slowly change along the ray trajectory, certain resonance conditions may be satisfied. The phenomena of scattering on resonance and capture into resonance is studied. These phenomena lead to destruction of the adiabatic invariance in the system. Bibliography: 12 titles.__________Published in Zapiski Nauchnykh Seminarov POMI, Vol. 300, 2003, pp. 173–179 相似文献
982.
Awatif A. Hendi 《Journal of Quantitative Spectroscopy & Radiative Transfer》2004,84(3):339-347
The neutron transport equation for a slab geometry with the extremely anisotropic scattering kernel is considered. The albedo and transmission factors are calculated using the variation method. The effect of the extremely anisotropic parameter on the variation of the slab albedo and transmission factor is calculated. The obtained results are compared with the published data. 相似文献
983.
984.
E.J. Avital 《Journal of sound and vibration》2004,270(3):483-494
A new Dispersion-Relation-Preserving (DRP) scheme has been developed using the Lax-Wendroff methodology. Two collocated grids are placed in a staggered formation and a staggered DRP scheme is used to calculate the spatial differentiation of the propagation and convection terms. A staggered filtering scheme of a six points stencil is developed to complete the transformation from one grid to another. Existing DRP Runge-Kutta schemes are used for the time marching. Stability limits and accuracy issues are investigated using a simple 1D advection equation. The new method is then tested for monopole and quadrupole radiation, diffraction effects of an aperture in a wall, and convection effects of shear flow. All demonstrate the good accuracy and numerical stability of the new method. 相似文献
985.
986.
A. V. Ershov 《Journal of Mathematical Sciences》2004,123(4):4198-4220
In this paper, we consider homotopic properties of bundles of algebras, matrix Grassmanians, and homotopy functors connected with bundles of algebras. 相似文献
987.
E. D. Tymchatyn M. Zarichnyi 《Proceedings of the American Mathematical Society》2004,132(9):2799-2807
We consider the question of simultaneous extension of (pseudo) metrics defined on nonempty closed subsets of a compact metrizable space. The main result is a counterpart of the result due to Künzi and Shapiro for the case of extension operators of partial continuous functions and includes, as a special case, Banakh's theorem on linear regular operators extending (pseudo)metrics.
988.
The transformation of a shear surface magnetoelastic wave by the motion of the 180° confining domain wall in a ferromagnet is considered. Changes in the wave spectrum due to the motion of the wall are correlated with the variations of the energies of the elastic and magnetic subsystems. The efficiency of surface wave transformation by the domain wall motion is estimated in terms of energy. The frequency dependences of the mean energy density of the wave are found. It is shown that the energy density grows with wall velocity. 相似文献
989.
Savos'kin M. V. Yaroshenko A. P. Shologon V. I. Galushko L. Ya. 《Russian Journal of Applied Chemistry》2003,76(7):1179-1181
Petroleum sorption on expanded graphite prepared from residual graphite hydrosulfate at 300-900°C was studied as influenced by pretreatment of the sorbent with water. 相似文献
990.
Kurenkov V. F. Zhelonkina T. A. Ryabysheva N. A. Lobanov F. I. 《Russian Journal of Applied Chemistry》2003,76(8):1310-1314
The influence of single- and double-charged cations on degradation of metal 2-acrylamido-2-methylpropanesulfonate-N-vinylpyrrolidine copolymers in aqueous solutions in the presence of potassium peroxodisulfate, K2S2O8, at 50 and 70°C was studied by viscosimetry. 相似文献