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101.
The gauge dependence of the effective action in two dimensional induced gravity with non-local action is investigated. The unique effective action in this theory on flat background is also discussed. The configuration-space metric dependence of the unique effective action is studied.On leave from Tomsk Pedagogical Inst., Tomsk, Russia Address after 1.08.92: Dept. of Physics, Hiroshima Univ., Higashi-Hiroshima 724, Japan 相似文献
102.
103.
S. N. Shevchenko 《Mathematical Notes》1994,55(5):534-542
This research was accomplished with the financial support of the Russian Foundation for Fundamental Research, Grant No. 93-011-225. 相似文献
104.
S. E. Korostovka A. I. Mikhaleva B. A. Trofimov S. G. Shevchenko M. V. Sigalov 《Chemistry of Heterocyclic Compounds》1992,28(4):406-408
2-Methyl-5-phenyl- and 2,5-diphenylpyrrole and 2-phenyl-, Z-[1-(2-phenylvinyl)]-3-phenyl-, and 4,5,6,7-tetrahydroindole, and 2,4-diphenyl-3,3-dimethyl-5-hydroxypyrroline have been obtained from the reaction of ketoximes with phenylacetylene, catalyzed by KOH-DMSO.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 485–488, April, 1992. 相似文献
105.
Numerical investigation of electric discharge in water 总被引:1,自引:0,他引:1
106.
The paper presents a solution to the problem of thermal conduction and thermoelasticity for a thin shallow spherical shell
heated by a concentrated or local impulsive heat source moving over the shell surface. It is assumed that temperature is linearly
distributed across the shell thickness and that the shell, on its sides, exchanges heat with the environment in accordance
with Newton’s law of cooling. The Fourier and Laplace transforms are used to find an analytic solution. The dependence of
the temperature field and stress/strain components on the type of heating and the form of heat source is studied
__________
Translated from Prikladnaya Mekhanika, Vol. 42, No. 11, pp. 85–92, November 2006. 相似文献
107.
Coating Platinum Nanoparticles with Methyl Radicals: Effects on Properties and Catalytic Implications
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Dr. Ronen Bar‐Ziv Dr. Israel Zilbermann Dr. Michael Shandalov Prof. Dr. Vladimir Shevchenko Prof. Dr. Dan Meyerstein 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(52):19000-19009
It was recently reported that the reaction of methyl radicals with Pt0 nanoparticles (NPs), prepared by the reduction of Pt(SO4)2 with NaBH4, is fast and yields as the major product stable (Pt0‐NPs)?(CH3)n and as side products, in low yields, C2H6, C2H4, and some oligomers. We decided to study the effect of this coating on the properties of the Pt0‐NPs. The results show that the coating can cover up to 75 % of the surface Pt0 atoms. The rate constant of the reaction, k( . CH3+Pt0‐NPs), decreases with the increase in the surface coverage, leading to competing reaction paths in the solution, which gradually become dominant, affecting the composition of the products. The methyl coating also affects the zeta potential, the UV spectra, and the electrocatalytic reduction of water in the presence of the NPs. Thus, the results suggest that binding alkyl radicals to Pt0 surfaces might poison the NPs catalytic activity. When the Pt0‐NPs are prepared by the reduction of a different precursor salt, PtCl62?, nearly no C2H4 and oligomers are formed and the methyl coating covers a larger percentage of the surface Pt0 atoms. The difference is attributed to the morphology of the Pt0‐NPs: those prepared from Pt(SO4)2 are twinned nanocrystals, whereas those prepared from PtCl62? consist mostly of single crystals. Thus, the results indicate that the side products, or most of them at least, are formed on the twinned Pt0 nanocrystal edges created between (111) facets. In addition, the results show that Pt0‐NPs react very differently compared with other noble metals, for example, Au0 and Ag0; this difference is attributed in part to the difference in the bond strength, (M0‐NP)?CH3, and should be considered in heterogeneous catalytic processes involving alkyl radicals as intermediates. 相似文献
108.
Rodrigo S. Targino Gareth W. Peters Georgy Sofronov Pavel V. Shevchenko 《Methodology and Computing in Applied Probability》2017,19(2):487-518
In this paper we demonstrate how to develop analytic closed form solutions to optimal multiple stopping time problems arising in the setting in which the value function acts on a compound process that is modified by the actions taken at the stopping times. This class of problem is particularly relevant in insurance and risk management settings and we demonstrate this on an important application domain based on insurance strategies in Operational Risk management for financial institutions. In this area of risk management the most prevalent class of loss process models is the Loss Distribution Approach (LDA) framework which involves modelling annual losses via a compound process. Given an LDA model framework, we consider Operational Risk insurance products that mitigate the risk for such loss processes and may reduce capital requirements. In particular, we consider insurance products that grant the policy holder the right to insure k of its annual Operational losses in a horizon of T years. We consider two insurance product structures and two general model settings, the first are families of relevant LDA loss models that we can obtain closed form optimal stopping rules for under each generic insurance mitigation structure and then secondly classes of LDA models for which we can develop closed form approximations of the optimal stopping rules. In particular, for losses following a compound Poisson process with jump size given by an Inverse-Gaussian distribution and two generic types of insurance mitigation, we are able to derive analytic expressions for the loss process modified by the insurance application, as well as closed form solutions for the optimal multiple stopping rules in discrete time (annually). When the combination of insurance mitigation and jump size distribution does not lead to tractable stopping rules we develop a principled class of closed form approximations to the optimal decision rule. These approximations are developed based on a class of orthogonal Askey polynomial series basis expansion representations of the annual loss compound process distribution and functions of this annual loss. 相似文献
109.
110.
Yu. N. Shevchenko R. G. Terekhov N. N. Tormakhov 《International Applied Mechanics》2007,43(3):291-302
Energy-coupled stress and strain measures are defined in Euler coordinates. They are used to analyze the relationship between
the first invariants of the stress and strain tensors for linearity and to determine strains at which the plastic component
of the first strain invariant can be neglected. It is established that this relationship remains linear within an engineering
plastic-strain tolerance of 0.2% irrespective of the value of strain intensity, which depends on the type of material and
its stress state
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Translated from Prikladnaya Mekhanika, Vol. 43, No. 3, pp. 60–72, March 2007. 相似文献