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排序方式: 共有667条查询结果,搜索用时 15 毫秒
61.
62.
Kamenetskikh A. S. Gavrilov N. V. Tretnikov P. V. Chukin A. V. Men’shakov A. I. Cholakh S. O. 《Russian Physics Journal》2021,63(10):1797-1803
Russian Physics Journal - The paper studies the α-phase formation and structure of Al2O3 coatings deposited by the anodic arc evaporation in the low temperature range of... 相似文献
63.
Jaroslav Menčík 《Meccanica》2007,42(1):19-29
The paper reviews the current state of the depth-sensing indentation (sometimes called nanoindentation), where the information
on material behaviour and properties is obtained from the indenter load and depth, measured continuously during loading and
unloading. It is shown how the contact parameters and principal characteristics are determined using pointed or spherical
indenters. Indentation tests can be used for the measurement of hardness and elastic modulus, and also of the yield stress
and for the construction of stress–strain diagrams, for the determination of the work of indentation and its components. Most
devices use monotonic loading and unloading, but some also enable measurement under a small harmonic signal added to the basic
monotonously increasing load. This makes possible continuous measurement of contact stiffness and the study of dynamic properties
and the determination of properties of coatings. One section is devoted to the measurement on viscoelastic-plastic materials,
where the delayed deforming must be considered during the measurement as well as in data evaluation. Instrumented indentation
can also be used for the study of creep under high temperatures. The paper also discusses the errors arising in depth-sensing
measurements and informs briefly about some other possibilities of the method. 相似文献
64.
研究了液芯光纤内不同体积比的甲苯和间二甲苯二元混合溶液的受激拉曼散射.实验结果表明:在不同的体积比之下二元溶液的环呼吸振动模式1002 cm-1,甲基的CH伸缩振动模式2920 cm-1 以及芳香环CH对称伸缩振动模式3058 cm-1的拉曼带同时产生受激拉曼辐射,并且2920 cm-1 和 3058 cm-1 拉曼带的一阶受激拉曼散射阈值要低于1002 cm-1拉曼带的二阶
关键词:
分子间费米共振
二元溶液
受激拉曼散射
拉曼散射截面 相似文献
65.
A. V. Men’shov 《Siberian Mathematical Journal》2014,55(3):440-450
We study the solvability of random systems of equations on the free abelian group ? m of rank m. Denote by SAT(? m , k, n) and \(SAT_{\mathbb{Q}^m } (\mathbb{Z}^m ,k,n)\) the sets of all systems of n equations of k unknowns in ? m satisfiable in ? m and ? m respectively. We prove that the asymptotic density \(\rho \left( {SAT_{\mathbb{Q}^m } (\mathbb{Z}^m ,k,n)} \right)\) of the set \(SAT_{\mathbb{Q}^m } (\mathbb{Z}^m ,k,n)\) equals 1 for n ≤ k and 0 for n > k. As regards, SAT(? m , k, n) for n < k, some new estimates are obtained for the lower and upper asymptotic densities and it is proved that they lie between (Π j=k?n+1 k ζ(j))?1 and \(\left( {\tfrac{{\zeta (k + m)}} {{\zeta (k)}}} \right)^n\) , where ξ(s) is the Riemann zeta function. For n ≤ k, a connection is established between the asymptotic density of SAT(? m , k, n) and the sums of inverse greater divisors over matrices of full rank. Starting from this result, we make a conjecture about the asymptotic density of SAT(? m , n, n). We prove that ρ(SAT(? m , k, n)) = 0 for n > k. 相似文献
66.
R. V. Men’shova S. P. Ermakova S. M. Rachidi A. H. Al-Hajje T. N. Zvyagintseva H. M. Kanaan 《Chemistry of Natural Compounds》2012,47(6):870-875
The variation of the polysaccharide composition of the brown alga Padina pavonica from the Mediterranean Sea was studied as a function of the collection season (April–July). It was shown that the principal
polysaccharide (8.0-13.3% of dry alga weight) was alginic acid. Its content did not undergo significant changes from April
to July. The content of water-soluble polysaccharides (laminarans and fucoidans) was low (<0.3% of dry alga weight). Water-soluble
polysaccharides of the studied alga were practically pure fucoidan. The amount of laminarans was insignificant (<0.01% of
dry alga weight). The content of fucoidans increased in alga samples from May through July. It was shown that P. pavonica is a promising source of alginic acids, which have a high capacity for gelation, and fucoidans, which exhibit antitumor action
against RPMI-7951 human melanoma cells. 相似文献
67.
68.
69.
Violeta Yeguas Gloria Inés Cárdenas-Jirón María Isabel Menéndez Ramón López 《Journal of mathematical chemistry》2010,48(1):137-144
The B3LYP density functional theory methodology in conjunction with the 6-31G(d,p) basis set has been used to characterize
triply N-confused meso-tetraphenylporphyrins. According to our computations, there is no a direct correlation between stability and aromaticity
as already found for non-substituted confused porphyrins. The inclusion of these substituents in the calculations provokes
a decrease of the planarity and aromaticity of these macrocycles along with a notable rise of their relative stability with
respect to the non-substituted case. Steric repulsions, both among phenyl rings and β atoms in the pyrrolic rings, and among H atoms in the core of the macrocycles, dominate over aromaticity in the establishment
of the most stable conformation of each isomer. 相似文献
70.
A. V. Fedorov A. L. Mikhailov A. V. Men’shikh D. V. Nazarov S. A. Finyushin V. A. Davydov 《Russian Journal of Physical Chemistry B, Focus on Physics》2007,1(6):600-605
The stability of the detonation front and the detonation parameters of composite liquid HEs of fueloxidizer type prepared from tetranitromethane, nitrobenzene, and nitromethane are studied using laser interferometry. 相似文献