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991.
N. F. Morozov Yu. K. Startsev Yu. V. Sud’enkov A. A. Suslikov G. A. Baranov A. A. Belyaev 《Technical Physics》2006,51(7):872-877
The radiation hardness and mechanical strength of single-and two-phase glasses are studied for the case when nanosecond laser pulses (λ= 1.06 μm, τ0.5 ≈ 12.5 ns) are focused inside the material. Laser interferometry is applied to measure the displacement of the free surface, find optical breakage thresholds, and carry out the fractographic analysis of damaged regions. It is shown that breakdown channels and damage regions develop in a nonlinear manner according to optical breakdown mechanisms, changing each other with an increase in the laser energy. The strength of the two-phase glass is found to be more than four times that of the single-phase glass, although their elastic properties differ insignificantly. Such a considerable difference in the hardness of these materials with chemically similar constitutents is attributed to the presence of the double-lattice nanometer-scale structure of the two-phase glass. 相似文献
992.
N. G. Rachkova I. I. Shuktomova A. I. Taskaev 《Russian Journal of Applied Chemistry》2006,79(5):715-721
Sorption of U, Ra, and Th from multicomponent aqueous salt solutions on hydrolyzed wood lignin is studied. The mechanism of radionuclide sorption from saline solutions is suggested on the basis of the results of sequential extraction. 相似文献
993.
V. M. Lembrikov V. V. Volkova G. P. Zhavoronkova L. V. Konyakhina 《Russian Journal of Applied Chemistry》2006,79(2):196-200
Data on the equilibrium distribution of phosphoric acid among the aqueous and organic phases in extraction of phosphoric acid with tri-n-butyl phosphate are presented for the system constituted by phosphoric acid produced from the Khibiny concentrate and by the extracting agent from the industrial system for purification of extraction phosphoric acid at 25–50°C. 相似文献
994.
P. K. Sazonov G. A. Artamkina I. P. Beletskaya 《Russian Journal of Organic Chemistry》2006,42(3):438-447
The nucleophilic aromatic and vinyl substitution using diaza-18-crown-6 as nucleophile afforded a number of its N,N’-diaryl-[aryl = 2,4-(NO2)2C6H3, 4-C5F4N, 4-CF3C6F4] and N,N’-dialkenyl-substituted derivatives [alkenyl = PhC(O)CH=CH, MeOCOCH=CH, (EtO2C)2C=C(Ph), etc.]. Arylation of diaza-18-crown-6 with nonactivated aryl bromides, such as 4-Me2NC6H4Br, 4-MeOC6H4Br, C6H5Br, and 4-CF3C6H4Br, was effected under catalysis by palladium complexes. N,N’-Diaryldiaza-18-crowns-6 having electron-acceptor substituents in the aromatic rings turned out to be incapable of forming complexes with metal cations, while their analogs containing electron-donor para-methoxy and para-dimethylamino groups gave complexes with barium perchlorate. 相似文献
995.
Within the framework of fractal analysis and percolation theory, an alternative model of reinforcement of filled polymers
is offered. Practically, this model can be used only to describe the reinforcement of nanocomposites, because, according to
the treatment considered, a pronounced reinforcement can be reached only at ratios of filler particle diameter to the statistical
segment length of about 10 and less. A theoretical calculation showed a good qualitative and quantitative agreement with experiments.
The type of reinforcement mechanism of composites is determined by the type of the space (fractal or Euclidean) in which the
structure of the polymeric matrix is formed.
__________
Translated from Mekhanika Kompozitnykh Materialov, Vol. 42, No. 6, pp. 797–802, November–Decem ber, 2006. 相似文献
996.
997.
V. G. Baklykov V. N. Charushin O. N. Chupakhin V. N. Drozd 《Chemistry of Heterocyclic Compounds》1987,23(4):465-469
Thiobenzhydrazides undergo cyclization with N-alkyl-quinoxalinium salts to give 5-alkyl-substituted 1,4,4a,5,10,10a-hexahydro-1,3,4-thiadiazino[5,6-b]quinoxalines, which undergo isomerization to 10-alkyl-substituted thiadiazinoquinoxalines when they are heated in ethanol or in the presence of acids.See [1] for Communication 20.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 557–561, April, 1987. 相似文献
998.
999.
1000.
In recent years there has emerged significant interest in low pressure radio frequency (rf) glow discharges which are used widely particulary in IC fabrication. Various parameters of the rf glow discharge have been found to be useful for its electrical characterization; however, there is no uniformity and agreement. Extensive experimental investigations on various discharge systems have shown, that the self-bias on the rf driven electrode, the complex conductivity and the breakdown characteristic are preferable parameters of rf discharges. Advantageously the self-bias and the complex conductivity should be presented in dependence on the pressure and the applied rf voltage. The discharge current cannot be measured quite accurately due to currents via leaky capacitors and the deviations from a sinusoidal form of the current due to nonlinearities. 相似文献