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The charge distribution of fragments originatingfrom the fission of the 236U compound nucleus is calculated within a stochastic approach based on Langevin equations. The elongation coordinate, the neck-thickness coordinate, and the charge-asymmetry coordinate are chosen as collective variables. The friction parameter of the charge mode is calculated on the basis of two nuclear-viscosity mechanisms, that of one-body and that of two-body dissipation. It is shown that the Langevin approach is applicable to studying isobaric distributions. In addition, the charge distribution in question is studied as a function of the excitation energy of the compound nucleus and as a function of the coefficient of two-body viscosity. 相似文献
3.
We describe equipment and a method for performing an experiment on a short meteor radio line of length 85 km. The feature of the experiment is monitoring of meteor-matter deposition to the atmosphere using a radar located at one point of the radio line with the simultaneous determination of the main radio-line characteristics. 相似文献
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I. I. Bardyshev A. D. Mokrushin A. A. Pribylov E. N. Samarov V. M. Masalov I. A. Karpov G. A. Emel’chenko 《Colloid Journal》2006,68(1):20-25
Some adsorption, structural, and annihilation characteristics of synthetic opals are measured. An analysis of these characteristics makes it possible to conclude that the total porosity in opals comprises macropores, which are in essence the voids between structure-forming spheres, and nanopores connected to the substructure of the spheres. The systems of macropores and nanopores are separated by narrow channels that collapse upon the thermal treatment of opals. The sizes of primary a-SiO2 particles and nanopores, which correspond to the voids between these particles, are estimated. 相似文献
7.
By reacting platinum with alkali metals (A = K, Rb, Cs) a new family of binary alkali metal platinides has been synthesized and characterized by chemical analysis, X‐ray powder diffraction, thermal analysis (DTA and DSC), and magnetic measurements. All three compounds exhibit similar XRD‐patterns with strong reflections that can be indexed on the basis of a rhombohedral crystal system (KxPt: a = 2.6462(1), c = 17.123(1); RbxPt: a = 2.6415(1) Å, c = 17.871(1) Å; CsxPt: a = 2.6505(1) Å, c = 18.536(1) Å; x < ½. The a lattice constant is independent on the alkali metal used and of value close to the Pt–Pt distance in NaPt2 (2.645Å). The c parameter increases monotonically with the growing atomic radius of the alkali metal. The average structure of the alloys consists of cubic close packed layers of platinum atoms with layers of disordered alkali metals in between. For all compounds besides the strong reflections small satellites are observed which cannot be indexed together with the rhombohedral peaks in any rational 3‐dimensional lattice. However, these satellites can be indexed as incommensurate modulations within the ab plane (found propagation vectors k = (0.1011, 0.2506, 0) for CsxPt, and k = (0.0168, 0.2785, 0) for RbxPt). 相似文献
8.
V. M. Karpov T. V. Mezhenkora V. E. Platonov G. G. Yakobson° 《Russian Chemical Bulletin》1990,39(5):1000-1004
Taking perfluoro-1,1-dialkylbenzocyclobutenes as examples, it has been shown to be possible to enlarge the four-membered ring in polyfluorobenzocyclobutenes to five-membered in the presence of SbF5, by cleavage of the four-membered ring followed by cyclization of the resulting polyfluorostyrene to the polyfluoroindane, which then undergoes further reactions. Perfluoro-1-methyl-1-ethylbenzocyclobutene isomerizes at 50°C in the presence of SbF5 to perfluoro-,-o -trimethylstyrene, which is reversibly converted at 130°C into perfluoro-1,2-dimethylindane. Perfluoro-l,l-diethylbenzocyclobutene isomerizes at 130°C in the presence of SbF5 to give perfluoro- -ethyl-,o -dimethylstyrene, which at 170°C gives perfluoro-2-methyl-3-ethylindene- and perfluoro-2-methyl-3-ethyl-4,5,6,7-tetrahydroindene. The last two compounds, together with perfluoro-o-dipropylbenzene, are obtained from per fluoro-1,2-diethylbenzocyclobutene-with SbF5 at 170°C. From perfluoro-1-methyl-2-ethylbenzocyclobutene with SbF5 at 95°C there is obtained perfluoro-1-ethylindane, while at 130°C, in addition to the latter compound, there are obtained perfluorinated 1,1-dimethylindane, 1,2-dimethylindane, ,,o-trimethylstyrene, 2,3-dimethylindene, and 2,3-dimethyl-4,5,6,7-tetrahydroindene.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1114–1120, May, 1990. 相似文献
9.
I. S. Vasil’chenko T. E. Shestakova V. N. Ikorskii T. A. Kuz’menko V. G. Vlasenko L. N. Divaeva A. S. Burlov A. I. Uraev I. V. Pirog G. S. Borodkin P. B. Chepurnoi I. G. Borodkina O. A. Beletskii O. A. Karpov I. E. Uflyand A. D. Garnovskii 《Russian Journal of Coordination Chemistry》2007,33(3):176-183
Azomethine derivatives of 1-amino-2-thiobenzimidazole (H2L) were synthesized and studied by IR and 1H NMR spectroscopy. Thiobenzimidazoline tautomeric form of these compounds was found to predominate in a solid state and DMSO solution. Novel mono-and binuclear metal chelates M(HL)2 and M2L2 (M = Ni(II), Cu(II), Co(II), Zn(II), Cd(II)) were synthesized on the basis of H2L derivatives and their composition and structures were established from IR, 1H NMR, EXAFS, and magnetochemical data. The composition of coordination sphere was shown to produce no effect on ferromagnetic exchange in binuclear Cu(II) complexes. 相似文献
10.
Aleksandr V. Prichodko Evgenii V. Shatkovski Sergei G. Yastrebov 《International Journal of Infrared and Millimeter Waves》1994,15(3):579-584
Photostimulated changes in thin carbon films deposited onto fused silica substrates by reactive magnetron sputtering and irradiated by the light of the first (1060nm) and the second (530nm) harmonics of a QW-switched Nd3+ AVG laser were investigated. The changes are supposed to be connected with the reordering of chemical bounds. 相似文献