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161.
S. N. Vorob'ev Yu. B. Nechaev S. L. Prosvirnin 《Radiophysics and Quantum Electronics》1992,35(8):440-451
The mutual coupling of the radiating elements in microstrip antennas is studied using a rigorous electrodynamic approach in which the field singularities at the radiator edges are taken into account with analytic accuracy. A spectral method is employed in combination with a method of semi-inversion by extraction of the Green-function singularity. The degree of interaction of the elements of microstrip structures at the fundamental and higher current harmonicsis determined, and the applicability of various approximations is assessed.Radio-Astronomy Institute, Academy of Sciences of Ukraine. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 35, No. 8, pp. 688–701, August, 1992. 相似文献
162.
V. A. Batanov V. S. Petriv A. O. Radkevich A. L. Telyatnikov A. Yu. Volkov 《International Journal of Infrared and Millimeter Waves》1991,12(7):703-715
High power IR pumping beams self focusing and defocusing in NH3 Raman laser is investigated by numerical methods on the basis of the solution of nonlinear quasioptical equations. The analysis of self focusing have been done for a wide range of parameters of radiation and of active medium. Spatial evolution of the beam configuration have been investigated for different regimes of nonlinear diffraction. Developed model enables to allow exactly for the spectroscopic features of active molecules and may be applied to the analysis of the properties of powerful optically pumped FIR lasers. 相似文献
163.
Exact cylindrically symmetric solutions are obtained for a class of interacting scalar and vector fields in a rotating Godel Universe. We select those with the properties of solitons with smooth decrease of the fields to asymptotics and those with sharp boundaries (droplets). It is shown that only some of the droplets are stable with respect to perturbations that preserve cylindrical symmetry.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 5, pp. 24–27, May, 1991. 相似文献
164.
The structure of the nematic-isotropic interfacial layer is studied theoretically for systems formed by rod-like and persistent macromolecules. It is shown that the width of interfacial layer is normally of the order of the straight part of a molecule. This allows us to use the approach which describes intermolecular interactions phenomenologically (i.e. it allows us to consider all interactions), at the same time this approach describes molecular flexibility microscopically (i.e. it allows us to study the effects of flexibility correctly). It was found, that non-monotonic gradient profiles in the surface layer of the order parameter or of the concentration of molecules as a function of the coordinate perpendicular to the interface are possible. For example, a thin layer with abnormal ordering of molecules along the surface may exist near the interface for some systems. 相似文献
165.
The impurity weakening of crystalline NaCl:Mg and NaCl:Mn associated with purification of the matrix in a melt is demonstrated.
This effect is manifested in a consistent change in the yield strength and mobility of dislocations. Its unusual temperature
dependence is determined: in a number of cases weakening becomes greater as the temperature is lowered within the interval
293–4.2 K. A deviation in the elastic region of the stress-strain curves is observed to increase as the temperature is lowered.
Plasticizing of crystalline NaCl is established: when the deformation temperature is lowered from 293 to 77 and 4.2 K the
rate of rise in the yield strength of Cd2+ and Sr2+ doped samples is lower than that of undoped samples. An explanation for this fact is proposed.
Fiz. Tverd. Tela (St. Petersburg) 39, 313–317 (February 1997)
Deceased. 相似文献
166.
Limit theorems for the logarithm of the likelihood ratio are proven. With their help the rate of decrease in the probability of errors of the second kind in the Neumann-Pierson criterion is established.Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 44, No. 10, pp. 1382–1388, October, 1992. 相似文献
167.
In this paper we examine clathrate formation in the tetraisoamylammonium propionate-water binary system. We have found formation
of four polyhydrates, two of which are metastable over the whole temperature range studied. All polyhydrate crystals were
isolated and their compositions and densities determined; for (i-C5H11)4NC2H5COO·36.5H2O, unit cell parameters were additionally found. The results are compared with data for tetra-n-butylammonium carboxylate
polyhydrates, and the structure of the title compounds is suggested. It is confirmed that the isoamyl radical stabilizes the
tetradecahedral void of the clathrate hydrate framework better than the n-butyl radical.
Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 35, No. 3, pp. 67–71, May–June, 1994.
Translated by L. Smolina 相似文献
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