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S. A. Udra V. I. Mashchenko L. A. Kazarin V. I. Gerasimov 《Polymer Science Series A》2008,50(12):1233-1237
The effect of shear fields on the rate of physical gelation in semidilute solutions of ultra-high-molecular-weight polyacrylonitrile in propylene carbonate and on the structural features of the resulting gels has been studied. At 30–70°C in the uniform shear field, the induction period of gelation decreases from several hours to several seconds with an increase in the shear stress. The patterns of these dependences are rather close at shear stresses above 20 Pa, while significant differences are observed at these temperatures only at low shear stresses (below 15 Pa). Depending on the shear stress, two types of gelation can be distinguished at 70°C. At stresses below 15 Pa, the polymer phase emerging in the course of shear deformation is aligned along shear lines and the sample is macroscopically nonuniform. At higher shear stresses, the structure of the sample is uniform throughout its bulk. 相似文献
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V.Yu. Baranovsky L.A. Kazarin A.A. Litmanovich I.M. Papisov 《European Polymer Journal》1984,20(2):191-194
Polycomplex formation between poly(methacrylic acid) and polyacrylamide in aqueous solutions has been studied by means of viscometry, potentionetry and elemental analysis. Stoichiometry of the polycomplex was found to be 1:1 with respect to unit-moles. I.R.-spectroscopic data give evidence of the co-existence of ladder-like regions and loops in the polycomplexes formed by poly(methacrylic acid) with polyacrylamide and poly(ethylene glycol). The reactivities of the same functional groups in ladder-like regions and loops are different. This difference has been shown taking as an example thermochemical reactions in the above polycomplexes. Dehydrocyclization in the poly(methacrylic acid) chain was found to occur in the loops of both polycomplexes. This intramolecular reaction in the polycomplex of poly(methacrylic acid) with polyacrylamide is followed by intermolecular formation of imide bonds in ladder-like regions. 相似文献
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It is proved that a finite group is soluble if the normalizer of every cyclic subgroup of prime-power order has a soluble supplement.Received: 31 January 2005 相似文献
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L.C. Kazarin 《代数通讯》2013,41(6):1001-1066
All the groups in this article are finite. A group G is said to be factorizable if G = AB with A,B proper subgroups of G . The general problem is to obtain information on structure of a factorizable group G = AB, under suitable restrictions on A and B . Recently E.Pisman [1] described the composition factors of factorizable group G = AB, where A and B are solvable groups of relatively prime orders.The aim of this paper is to prove the following more general result. 相似文献
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Pt/W/Cr/SiC Schottky-barrier diodes that retain good electrophysical parameters up to 450°C are studied. With the Auger electron spectroscopy (AES) method, it is shown that the thermal stability is provided by using a multilayer metal composition that ensures the metal/SiC interface stability. The surface-barrier structures obtained are tested for radiation hardness. They are irradiated by fast neutrons with a fluence of 4.42×1015 n/cm2 and attendant γ radiation with a dose of 8.67×105 R in the concentration range of N d-N a=1016−5×1017 cm−3. Irreversible modifications of the structures at N d-N a≤8×1016 cm−3 are found. The degradation of the parameters is inversely proportional to the doping level. 相似文献
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The structure of the adjoint groupR
o of a finite nilpotentp-algebraR is considered under suitable additional conditions. For instance, the cases whereR contains a large power subalgebra or has dimension at most 5, or whenR
o has small Prüfer rank, are studied.
Translated from Itogi Nauki i Tekhniki, Seriya Sovremennaya Matematika i Ee Prilozheniya. Tematicheskie Obzory. Vol. 63, Algebra-13,
1999. 相似文献
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