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991.
B. P. Harlamov 《Journal of Mathematical Sciences》2005,128(1):2625-2639
Semi-Markov processes of diffusion type in the d-dimensional space (d > 1) are considered. We assume that the transition generating function of such a process satisfies a second-order differential equation of elliptic type. We apply methods of differential equations theory, especially of the theory of the Dirichlet problem, to study the transition generating function for a small neighborhood of the initial point of the process. Asymptotic expansions in the small scale parameter are obtained both for the first exit point distribution density and for the first exit time expectation for the case where the trajectory of the process leaves a small neighborhood of the initial point. We prove the existence of the Dynkin characteristic operator determined by a decreasing sequence of neighborhoods. Bibliography: 9 titles.__________Translated from Zapiski Nauchnykh Seminarov POMI, Vol. 293, 2003, pp. 226–251. 相似文献
992.
993.
The finite-difference method is a numerical technique for obtaining approximate solutions to differential equations. The main
objective of the present study is to give a new aspect to the finite-difference method by using a variational derivative.
By applying this formulation, accurate values of the buckling loads of beams and frames with various end supports are obtained.
The performance of this formulation is verified by comparison with numerical examples in the literature
__________
Published in Prikladnaya Mekhanika, Vol. 41, No. 7, pp. 139–144, July 2005. 相似文献
994.
L. B. Beinenson 《Journal of Mathematical Sciences》2005,129(2):3730-3756
For an arbitrary poset H and measure ρ on H × R (where R is the real axis), we construct a monotone decreasing stochastic field ηρ and compute its finite-dimensional distributions. In the case where H is a Λ-semilattice and the measure ρ satisfies additional conditions, we compute various characteristics of the field ηρ such as the expectation of the field value at a point, variance of the field value at a point, and correlation function of the field. The described construction of random fields gives a new method for constructing positive definite functions on posets. Bibliography: 6 titles.__________Translated from Zapiski Nauchnykh Seminarov POMI, Vol. 301, 2003, pp. 92–143. 相似文献
995.
Studies of thickness and temperature dependencies of the dielectric susceptibility of nitrobenzene interlayers formed on conductive substrates were carried out. The obtained data were processed under the assumption of the existence of dimers (with opposite directions of molecular dipole moments) in orientationally ordered wall-adjacent layers. The results were treated on the basis of Lifshits theory. 相似文献
996.
A. Peláiz-Barranco O. García-Zaldívar F. Calderón-Piñar 《Solid State Communications》2005,133(8):515-519
The Ac behaviour of PLZT 6/80/20 ferroelectric ceramics was analyzed around and above the phase transition. Two relaxation processes are identified, showing that the so-called ‘universal relaxation law’ holds for the ceramics. A critical point in the values of the Ac conductivity, around the temperature corresponding to the maximum of the dielectric losses, is observed below the transition temperature due to the relaxor behaviour. The frequency dependence of the Ac conductivity at various temperatures and the hysteresis loops show classical relaxor behaviour with a diffuse phase transition. 相似文献
997.
998.
999.
1000.
I. A. Uspenskaya Z. S. Vakhovskaya M. M. Efremova M. L. Kovba A. L. Emelina Zh. V. Dobrokhotova Yu. V. Goryushkina L. A. Tiflova A. A. Popova A. S. Monaenkova 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2006,80(4):529-534
The thermodynamic properties of the Ln2BaO4 phases (Ln = Dy, Ho, Sm) were studied by the electromotive force method with a fluoride electrolyte (890–1180 K), solution calorimetry in 1.07 N hydrochloric acid at 298.15 K, and differential scanning calorimetry (298–860 K). The experimental data were jointly processed, and the thermodynamic functions of the compounds over the temperature range 298–1200 K were calculated. 相似文献