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1.
Using the relations of the improved model of layered anisotropic shells based on the straight line assumption taking account of the thermal compression over the thickness we obtain a resolvent system of equations for shells whose properties depend on temperature. We carry out a study of the stresses in a two-layer cylindrical shell formed by winding as a function of the winding angle.
Translated fromMatematicheskie Metody i Fiziko-Mekhanicheskie Polya, Issue 35, 1992, pp. 82–85. 相似文献
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Temperature and frequency dependence of dielectric permittivity and tangent of the dielectric loss angle are studied in epitaxial gallium arsenide structures. It is shown that nonmonotonic change in with temperature is caused by change in the volume of conductive gallium microinclusions and a difference between the structural perfection of the layer and substrate. The space charge relaxation time on inhomogeneities is evaluated (10–5–10–6 sec) and its contribution to GaAs dielectric properties is evaluated. An oscillation in dielectric permittivity upon heating is observed and explained.Deceased.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 2, pp. 18–21, February, 1989. 相似文献
4.
Sergei V. Kostjuk Alexei Yu. Dubovik Irina V. Vasilenko Alexander N. Frolov Fyodor N. Kaputsky 《European Polymer Journal》2007,43(3):968-979
The cationic polymerization of styrene with the 2-phenyl-2-propanol (CumOH)/AlCl3 · OBu2 initiating system at various dibutyl ether concentrations in a mixture of 1,2-dichloroethane and n-hexane (55:45 v/v) at −15 °C was investigated. The experimental results showed that an increase in dibutyl ether concentration leads to a noticeable decrease in the polymerization rate as well as to the more controlled polymerization in terms of molecular weight (Mn) and molecular weight distribution (MWD) evolutions. The kinetic investigation revealed that the polymerization proceeds in two stages. The first stage is characterized by high polymerization rate and slow initiation relative to propagation. During this stage molecular weight decreases or does not change and MWD increases with conversion. In the second stage considerably slower quasiliving polymerization of styrene occurs. The quasiliving nature of the styrene polymerization by the CumOH/AlCl3 · OBu2 system is proved and mechanistic scheme of the polymerization is proposed. 相似文献
5.
L. M. Eremeeva T. V. Moskovkina Yu. V. Vasilenko A. N. Saverchenko V. A. Kaminskii M. N. Tilichenko 《Chemistry of Heterocyclic Compounds》1979,15(2):202-207
Compounds that contain a hydrogenated azolopyridine structure are formed in the reaction of various types of 1,5-diketones with ethanolamine, o-aminophenol, o-phenylenediamine, and aroylhydrazines; compounds that include a hydrogenated azinopyridine structure were obtained by the reaction of diketones with 3-aminopropanol and anthranilic acid. The hydrocyanation and oxidation of the compounds obtained were studied.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 240–245, February, 1979. 相似文献
6.
P. S. Timashev N. N. Vorobieva N. V. Minaev Yu. A. Piskun I. V. Vasilenko S. G. Lakeev S. V. Kostyuk V. V. Lunin V. N. Bagratashvili 《Russian Journal of Physical Chemistry B, Focus on Physics》2016,10(8):1195-1200
A series of lactide and ε-caprolactone copolymers containing 4–24 mol % of ε-caprolactone with 20- to 30-kDa molecular weights are synthesized. Based on them, porous materials are produced by foaming in supercritical carbon dioxide. The pore size was shown to decrease with increasing ε-caprolactone content in copolymer, while the porosity of the entire sample was not altered. The resulting pore size also decreases if 7 wt % polyethylene glycol is added to the initial monomer mixture. The Young’s modulus of the porous samples decreases with increasing ε-caprolactone content and when polyethylene glycol is added. 相似文献
7.
K. M. Kondratyuk E. I. Lukashuk A. V. Golovchenko A. N. Vasilenko V. S. Brovarets 《Russian Journal of General Chemistry》2013,83(1):46-53
Various approaches to the synthesis of new derivatives of diethyl 5-mercapto-2-R-1,3-oxazole-4-ylphosphonates were considered. The behavior of these compounds in the presence of mineral acids and alkalis resulting in the synthesis of previously unknown 5-mercapto-2-R-1,3-oxazole-4-ylphosphonic acids was studied. 相似文献
8.
Kirill V. Zaitsev Yulia A. Piskun Yuri F. Oprunenko Sergey S. Karlov Galina S. Zaitseva Irina V. Vasilenko Andrei V. Churakov Sergei V. Kostjuk 《Journal of polymer science. Part A, Polymer chemistry》2014,52(9):1237-1250
The aluminum complexes containing two iminophenolate ligands of the type (p‐XC6H4NCHC6H4O‐o)2AlR' (R′=Me ( 3, 4 ) or R′=O(CH2)4OCH=CH2 ( 5, 6 ), X=H ( 3, 5 ), F( 4, 6 )) were synthesized and characterized by 1H, 13C NMR spectroscopy, and X‐ray crystallography. The reaction of AlMe3 with two equivalents of substituted iminophenols gave five‐coordinated {ONR}2AlMe ( 3, 4 ) complexes. Subsequent reaction of these methyl complexes with unsaturated alcohol, HO(CH2)4OCH=CH2, resulted in target compounds 5 and 6 in a good yield. It was shown that the complexes ( 3 ‐ 6 ) are monomeric in solution (NMR) and in solid state (X‐ray analysis). The catalytic activity of the complexes 5 and 6 towards ring‐opening polymerization (ROP) of ?‐caprolactone and d,l ‐lactide was assessed. Complex 5 showed higher activity as compared with 6 , while both of these catalysts induced controlled homo‐ and copolymerization to afford the macromonomers with high content of vinyl ether end groups (Fn > 80%) in a broad range of molecular weights (Mn = 4000–30,000 g mol?1) with relatively narrow MWD (Mw/Mn = 1.1–1.5). © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 1237–1250 相似文献
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S. A. Chumachenko O. V. Shablykin A. N. Vasilenko V. S. Brovarets 《Russian Journal of General Chemistry》2013,83(9):1710-1715
Reaction of 2-methoxy-5-morpholino-1,3-oxazole-4-carbonitrile with benzylamine, phenethylamine and phenylhydrazine results in the new substituted 5-amino-2,3-dihydro-1H-imidazol-2-ones. 相似文献