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91.
A model kinetic equation is constructed for the transport of a massless Bose gas. This equation is applied to solve the boundary
value problem for the transport of radiation in the half-space occupied by a dispersive medium that is in local thermal equilibrium
with the radiation. It is shown that the difference in temperature between the dispersive medium and the incident radiation
substantially depends on the character of the scattering properties of the particles in the medium.
Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 111, No. 3, pp. 462–472, June, 1997. 相似文献
92.
93.
94.
V. A. Lyubetsky 《Algebra and Logic》1997,36(3):169-181
A set theory ZFI′ which does not employ the Law of the Excluded Middle φ ∀ ⊥ φ, for all φ, retians the stock of expressive
capacities of the classical set theory ZF, on the one hand, and has many of the features of an effective theory on the other.
In the article, a broad class of formulas σ is constructed for which ZF ⊥ σ implies ZFI′ ⊥ σ. This result provides a generalization
of Friedman's theorem on AE-arithmetic formulas. Besides, we prove transfer theorems of classical logic for the case of rings;
in particular, Hilbert's theorem on zeros and Artin's theorem on ordered fields are extended to the case of regular f-rings,
and we bring in appropriate upper bounds for them.
Supported by RFFR grant No. 93-012-1027.
Translated fromAlgebra i Logika, Vol. 36, No. 3, pp. 282–303, May–June, 1997. 相似文献
95.
A. N. Urumbaev 《Ukrainian Mathematical Journal》1997,49(2):320-326
We show that the modified method for finite-dimensional approximation of solutions of Fredholm integral equations of the first
kind presented in this paper is more economical than traditional methods for finite-dimensional approximation.
Institute of Mathematies, Ukrainian Academy of Science, Kiev. Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 49,
No. 2, pp. 289–295, February, 1997. 相似文献
96.
O. A. Dubovskii 《Physics of the Solid State》1998,40(11):1937-1941
Solutions of the dispersion equations for polariton states in finite one-dimensional crystals of arbitrary length are obtained.
The appearance and evolution of the radiative and nonradiative polariton branches are traced as the length varies from two
monomers to limiting values, above which the spectrum no longer undergoes significant changes. The dependences of the frequencies
and radiative widths on the polariton wave vector are found for various orientations of the dipole moment of the quantum transition.
The evolution of superradiance as the length of the crystal increases is traced. Some previously unknown significant features
of the polariton spectrum are noted particularly the damping of the branch traditionally termed nonradiative as a consequence
of emission from the end faces.
Fiz. Tverd. Tela (St. Petersburg) 40, 2136–2140 (November 1998) 相似文献
97.
The microwave subsidiary absorption threshold in tangentially magnetized yttrium-iron-garnet (YIG) films was measured as a function of the static magnetic field, film thickness and decrease in the 0.3–3 μm range is observed. The effect is explained quantitatively by using modified Damon-Eshbach dispersion relations which take into account exchange interactions.
The effect of temperature on hcrit, the smallest threshold field amplitude, in the 250<T< 450 K temperature range can be expressed by an empirical relationship hcrit Ms(T)-1.6 where Ms is the saturation magnetization. This hcrit vs Ms relationship is similar to that obtained for the magnetization dependence of parallel pump thresholds in Li-Ti ferrite compounds. 相似文献
98.
S. A. Malyugin 《Siberian Mathematical Journal》1993,34(2):297-306
99.
H. Grübmeier A. Naoumidis G. Stochniol A. Tsoga 《Fresenius' Journal of Analytical Chemistry》1995,353(3-4):393-398
Chemical interactions at the phase boundaries of materials applied for the solid oxide fuel cell (SOFC) have been studied by EPMA. The chemical reactivity at the interface of Lay-xSrxMnO3/ZrO2-Y2O3 is dependent on the stoichiometry (y) and the Sr content (x) of the perovskite. Typical reaction products (zirconates) and a diffusion zone in the ZrO2–Y2O3 have been observed. The extension of cation release (Mn) is related to the increasing chemical activity of Mn oxide in the perovskite by the Sr substitution for La. The wettability of the metal/oxide interface in the anode cermet (Ni/ZrO2–Y2O3) has been found to be influenced by chemical reactions resulting from the applied reducing atmosphere with high carbon activity. The disintegration of ZrO2–Y2O3 in contact with molten Ni or Ni-Ti and Ni-Cr alloys leads to the redeposition of Y2O3-enriched oxides and also to Zr-rich intermetallic compounds and eutectics. 相似文献
100.
A generalization of strong regularity around a vertex subset C of a graph Γ, which makes sense even if Γis non-regular, is studied. Such a structure appears, together with a kind of distance-regularity around C , when an spectral bound concerning the so-called predistance polynomial of C is attained. As a main consequence of these results, it is shown that a regular (connected) graph Γwith d + 1 distinct eigenvalues is distance-regular, and its distance- d graph Γ d is strongly regular with parameters a = c , if and only if the number of vertices at distance d from each vertex satisfies an expression which depends only on the order of Γand the different eigenvalues of Γ. 相似文献