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991.
992.
V. A. Zubkov S. N. Kovalenko V. P. Chernykh S. M. Ivkov 《Chemistry of Heterocyclic Compounds》1994,30(6):665-670
Methods of synthesizing previously unknown derivatives of coumarin — 2-(N-R-imino)-2H-1-benzopyrans, where R = Alk, Ar — are proposed. Possibilities of alternative synthetic schemes are discussed, and hypotheses concerning probable mechanisms of the reactions are formulated.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 760–766, June, 1994. Original article submitted May 23, 1994. 相似文献
993.
V. P. Kondilenko V. Ya. Chorny A. M. Eremenko 《Reaction Kinetics and Catalysis Letters》1993,50(1-2):203-207
The influence of temperature in the 20–100°C range on processes of bimolecular interaction in the aerosil-phenanthrene-trinitrobenzene system has been studied. Temperature-stimulated CTC accumulation on the surface is found. Activation energies of complex formation are estimated. Quenching of phenanthrene fluorescence by acceptor has a mixed static and dynamic character. 相似文献
994.
V. M. Ogenko A. V. Fesenko N. D. Konovalova V. I. Stepanenko 《Reaction Kinetics and Catalysis Letters》1993,50(1-2):169-173
It has been established that CO oxidation with excess O2 on Ni/Al2O3 forms an inhomogeneous NiO contact surface that smoothes critical effects in the sharp reactivity change. 相似文献
995.
H. Tietze-Jaensch D. Sieger R. Geick W. Zulehner A. de Geyer 《Applied Physics A: Materials Science & Processing》1992,54(1):19-21
The formation of silicon oxide precipitates from Czochralski grown silicon depends on the time and temperature of the heat treatment as well as on the initial content of interstitially dissolved oxygen. Samples containing between 5×1017 Oi/cm3 and 13×1017 Oi/cm3 have been heated at 750° C for 96 h. SiO2 precipitates of various shape and size have been obtained and investigated by means of small angle neutron scattering (SANS) in the Q-range 0.05 Å–1<Q<0.2 Å–1. The obtained SANS patterns reveal a typical anisotropy of their intensity distribution, which splits into a central peak at Q<0.1 Å–1 due to the shape of the individual particles and a number of weak intensities for large Q-values, originating from a correlation between defects, possibly between the precipitates. While these correlation peaks in the SANS patterns are seen best for rather low values of about (5–7)×1017 Oi/cm3 oxygen content, the central peak anisotropy is most pronounced for higher values of ca 10×1017 Oi/cm3. The integrated intensity of the central peak increases with increasing initial oxygen content. For comparison, untreated samples of the same initial oxygen content do not reveal any anisotropic SAN scattering or a broadened central peak beam. 相似文献
996.
V. Yu. Novokshenov 《Theoretical and Mathematical Physics》1992,93(2):1279-1291
Potentials of the Schrödinger equation, slowly decreasing at infinity, generate an infinite discrete spectrum converging to zero. The inverse scattering problem in the class of such potentials is solved in a constructive way similarly to the classical soliton theory. An infinite-dimensional system arising from Backlund transformations over soliton solutions plays the role of a determinant representation of the potential. The asymptotics at infinity is derived by use of the Poisson summation formula. An application to the long-time asymptotics of the solution of the Korteweg-de Vries equation is considered.In Memory of Prof. M. C. PolivanovInstitute of Mathematics, Urals Branch, Russian Academy of Sciences, 450000, Chernyshevsky str. 112, Ufa, Russia. Published in Teoreticheskaya i Matematicheskaya Fizika, Vol. 93, No. 2, pp. 286–301, November, 1992. 相似文献
997.
998.
V. B. Kuznetsov 《Theoretical and Mathematical Physics》1992,91(1):385-404
Integrable systems associated with separation of the variables in real Riemannian spaces of constant curvature are considered. An isomorphism between all such systems and the hyperbolic Gaudin magnet is established. This isomorphism is used in a classification of all coordinate systems that admit separation of the variables, the basis of which is the classification of the correspondingL operators of the Gaudin magnet.Leningrad State University. Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 91, No. 1, pp. 83–111, April, 1992. 相似文献
999.
V. A. Klyachin 《Siberian Mathematical Journal》1992,33(5):928-932
Volgograd. Translated fromSibirskiî Matematicheskiî Zhurnal, Vol. 33, No. 5, pp. 201–205, September–October, 1992. 相似文献
1000.
Cheriyan and Hagerup developed a randomized algorithm to compute the maximum flow in a graph with n nodes and m edges in O(mn + n2 log2n) expected time. The randomization is used to efficiently play a certain combinatorial game that arises during the computation. We give a version of their algorithm where a general version of their game arises. Then we give a strategy for the game that yields a deterministic algorithm for computing the maximum flow in a directed graph with n nodes and m edges that runs in time O(mn(logm/n log nn)). Our algorithm gives an O(mn) deterministic algorithm for all m/n = Ω(nε) for any positive constant ε, and is currently the fastest deterministic algorithm for computing maximum flow as long as m/n = ω(log n). 相似文献