排序方式: 共有35条查询结果,搜索用时 15 毫秒
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V. A. Krylov O. Yu. Chernova Yu. M. Salganskii L. S. Malygina A. P. Kotkov 《Journal of Analytical Chemistry》2003,58(8):750-755
It is shown that the results of determining methane in high-purity arsine by reaction gas chromatography can be overestimated by more than two orders of magnitude. This overestimation is caused by the formation of methane as a side product of the reaction. Cryogenic preconcentration at the injection stage is proposed to improve the accuracy of determination of methane, and the cryofocusing of impurity hydrocarbons is proposed to improve separation. Detection limits of (3–10) × 10–6 vol % are achieved for C1–C5 hydrocarbons. 相似文献
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L. T. Eremenko L. B. Romanova M. E. Ivanova V. S. Malygina L. S. Barinova G. V. Lagodzinskaya V. P. Lodygina I. L. Eremenko G. G. Aleksandrov 《Russian Chemical Bulletin》2007,56(7):1408-1422
New substituted cubane-1,4-dicarboxamides and 4-bromocubanecarboxamides containing the nitroxyl group and amino acid fragments along with the cubane skeleton were synthesized. The cardiac pharmacological activity (both the effect on aorta relaxation and the calcium channel blocking activity) of most of nitroxyalkyl derivatives is equal to or higher than that of N-(2-nitroxyethyl)nicotinamide (nicorandil). 相似文献
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V. V. Malygina 《Russian Mathematics (Iz VUZ)》2014,58(3):14-25
We obtain sharp and effective conditions of positiveness of the fundamental solution for linear scalar difference equations. Two approaches are realized, namely, an analytic one (in terms of properties of the characteristic equation) and a geometric one (in terms of a domain in the parameter space of the problem). 相似文献
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V. V. Malygina 《Russian Mathematics (Iz VUZ)》2008,52(7):15-23
For a differential equation with a distributed varying delay, sufficient criteria for the asymptotic and uniform stability of solutions are obtained. The constructed examples demonstrate exactness of the boundary of the obtained stability domain. 相似文献
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We consider a class of scalar linear differential equations with several variable delays and constant coefficients. We treat the coefficients and maximum admissible values of delays as parameters that define a family of equations of the considered class. Using the necessary and sufficient stability conditions established in preceding papers, we obtain an analytic form and a geometric interpretation of boundaries of stability domains for families of equations with a small number of independent parameters. 相似文献
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Makarova M. A. Malygina A. S. Pyshnograi G. V. Rudakov G. O. 《Journal of Applied Mechanics and Technical Physics》2021,62(7):1063-1071
Journal of Applied Mechanics and Technical Physics - The modified Vinogradov–Pokrovskii rheological model is used to describe the occurrence of stresses in a polymer melt under uniaxial... 相似文献
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We consider a linear scalar difference equation with several variable delays and constant coefficients. The coefficients and maximum admissible values of delays are supposed to be the set of parameters that define a family of equations of the investigated class. We obtain effective necessary and sufficient conditions of the uniform and exponential stability of solutions to all equations of the family, as well as the conditions of the sign-definiteness and monotonicity of stable solutions. 相似文献
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Siberian Mathematical Journal - Considering autonomous delay functional differential equations, we establish some oscillation criterion that reduces the oscillation problem to computing the only... 相似文献
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V. P. Kuznetsov A. V. Makarov S. G. Psakhie R. A. Savrai I. Yu. Malygina N. A. Davydova 《Physical Mesomechanics》2014,17(4):250-264
The paper studies tribological aspects of nanostructuring burnishing of steels. The efficiency of the process in improving the tribological properties of steels is assessed as regards the choice of an indenter material and lubricant-coolant reasoning from the friction coefficient at the “indenter-treated part” contact and from the absence of adhesive bond and fatigue microcracks. It is shown that synthetic diamond and dense boron nitride are promising indenter materials for nanostructuring burnishing of corrosion-resistant 20X13 steel and cement 20X steel. It is demonstrated that nanostructuring burnishing increases the wear resistance of structural steels under abrasive action and sliding friction in different media (lubricant, water, air, and argon) due to suppressed processes of microcutting, plastic edging, fatigue and oxidation wear, and adhesive bonding. 相似文献