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981.
982.
N. M. Zoumakis 《Il Nuovo Cimento C》1992,15(2):247-250
Summary An approximate relationship between the gradient, Ri, and the bulk Richardson number, Rib, for unstable atmospheric conditions, is suggested. The proposed relation shows much better agreement with the estimation
provided by a numerical iterative method than the usual approximations suggested by Louis and Byun. 相似文献
983.
984.
The methods applied for natural uranium, radium and thorium determinations in water samples are shortly presented together with some preliminary results. The measurements will be continued as part of an extended program of ecological study of the Danube Delta area. 相似文献
985.
The rate of nucleophilic substitution at the phosphorus centre of dialkyl methylphosphonates by methoxide and ethoxide has been studied to investigate the possible involvement of hexacoordinated phosphorus species in this reaction. For alkoxide concentrations less than ca. 1.5 M the rate increases with the square of alkoxide concentration. However, consideration of the activity of the alkoxides, represented by an appropriate acidity function, reveals that only one equivalent of alkoxide is involved in the rate-determining step. Thus, there is no requirement to invoke the intermediacy of a hexacoordinated species in the reaction pathway. © John Wiley & Sons, Inc. 相似文献
986.
A. Yu. Khodjamirian
A. G. Oganessian
《Nuclear Physics B》1992,380(3):431-443The leading nonperturbative contribution to the cross section of charm production in two-photon collisions is calculated in QCD. Operator expansion is used and the c-quark interaction with vacuum gluon condensate is taken into account. As a result, the moments of the charm contribution to the photon structure function are obtained. The moments with sufficiently high numbers turn out to be sensitive to the gluon condensate. 相似文献
987.
The object of the paper is to study the absolute matrix summability problem of Fourier series, conjugate series and some associated
series under a new set of conditions on matrix methods, generalising many known results in the literature. 相似文献
988.
Physical Engineering Institute, Moscow. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 34, No. 5, pp. 565–574, May, 1991. 相似文献
989.
I obtain exact solutions for the quantum-mechanical harmonic oscillator with a perturbation potential which belongs to a class of polynomial functions of 1/r. I show that some of the eigenfunctions enable the calculation of expectation values in closed form and are therefore suitable trial functions for the application of the variational method to related nonsolvable problems. 相似文献
990.
Leningrad Polytechnic Institute. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 34, No. 5, pp. 583–589, May, 1991. 相似文献