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961.
A. R. Volkov B. V. Shul'gin T. I. Polupanova V. N. Lebedev A. A. Nagornyi V. L. Petrov Yu. F. Kargin 《Journal of Applied Spectroscopy》1991,54(6):585-590
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 54, No. 6, pp. 970–975, June, 1991. 相似文献
962.
In a twisted nematic liquid crystal cell we report and study the self-transparency effect induced by the creation of an isotropic droplet. A simple theoretical model is presented and good agreement with experimental data is found. In a two beams configuration transistor-like behavior is observed and theoretically discussed. 相似文献
963.
M. Heusler 《General Relativity and Gravitation》1991,23(2):189-207
The field equations for homogeneous models in an arbitrary number of dimensions form a Hamiltonian system with constraint forces. Due to the monotonic behavior of the determinant of the induced metric, the evolution of the system can be interpreted as the motion of a particle in an explicitly time-dependent potential. Considering vacuum models, we show that this explicit time-dependence can be eliminated. Using the scaling properties of the Ricci tensor we obtain an autonomous system, for which we can also find a Liapunov function in terms of the n-dimensional Ricci curvature. 相似文献
964.
In the following we find all of the three-dimensional flat spacetimes which are static and rotationally symmetric. 相似文献
965.
Dominant nonlinear electric dipole polarizations at the interaction of fundamental and second harmonic waves in centrosymmetric media without and with memory are treated in this paper. The process of forming a permanent spatially periodic quadratic susceptibility grating in the medium with memory is described from the phenomenological point of view.Dedicated to the Czechoslovak Student Movement '89. 相似文献
966.
967.
968.
A. V. Bernshtein 《Journal of Mathematical Sciences》1991,53(6):592-595
An existence theorem is proved for a strictly majorizing test of composite hypotheses. Statistical corollaries of the theorem are explored.Translated from Statisticheskie Metody Otsenivaniya i Proverki Gipotez, pp. 73–78, 1986. 相似文献
969.
The variational problem of contact equilibrium of a punch and an elastic body is considered. An equivalent formulation of the problem is given in variational inequality form. Existence and uniqueness of the solution is investigated in a particular case. A penalty method is proposed for approximate solution of the problem.Translated from Vychislitel'naya i Prikladnaya Matematika, No. 56, pp. 97–103, 1985. 相似文献
970.
D. A. Tikhomirov O. S. Slyadevskaya A. V. Eremeev 《Chemistry of Heterocyclic Compounds》1991,27(9):966-969
A convenient method of synthesis of 2-(methoxycarbonylmethylene)-substituted imidazolidines and imidazolidinium bromides, and also of bicyclic diazo compounds has been developed starting from methyl bromopropiolate and ethylenediamine and its derivatives.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1205–1208, September, 1991. 相似文献