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991.
Integrable systems of NLS type in 2+1 dimensions are studied in three ways: their special solutions by Lie point symmetries, breaking-solutions by the ISM, as well as the non-isospectral problems.Department of Mathematics, Statistics and Computing Science, University of New England, Armidale N.S.W. 2351, Australia. E-mail: zhuhan@neumann.une.edu.au, xhe@metz.une.edu.au Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 99, No. 3, pp. 382–389, June, 1994. 相似文献
992.
On the Global Stability of Cooperative Systems 总被引:7,自引:0,他引:7
Suppose that F is a C1 cooperative vector field on X, whereX = Rn or Int , or [[p, q]].We prove that the unique equilibrium of F is globally asymptoticallystable if and only if every forward semi-orbit has compact closurein X. 相似文献
993.
We prove that a convex functionf C[–1, 1] can be approximated by convex polynomialsp
n
of degreen at the rate of 3(f, 1/n). We show this by proving that the error in approximatingf by C2 convex cubic splines withn knots is bounded by 3(f, 1/n) and that such a spline approximant has anL
third derivative which is bounded by n33(f, 1/n). Also we prove that iff C2[–1, 1], then it is approximable at the rate ofn
–2 (f, 1/n) and the two estimates yield the desired result.Communicated by Ronald A. DeVore. 相似文献
994.
995.
996.
997.
Kui Zhao Xiuqin Lu Yehao Cheng Qingli Li Min Li Zhichang Li Jiyu Guo Shuyuan Li Qinghua Zhang Xiaobin Song Chenglie Jiang 《Zeitschrift für Physik A Hadrons and Nuclei》1994,348(2):95-98
Angular distributions of elastic and inelastic scattering have been measured for152Sm+12C at 63.2 MeV and148Nd+16O at 90.9 MeV. An evident interference pattern in the inelastic scattering has been observed for the first time in a strong Coulomb coupling system.We are indebted to Dr. S. Pieper for supplying the Ptolemy Program. One of us (Chenglie Jiang) would like to acknowledge the Argonne National Laboratory for the opportunity given, to perform theoretical calculations with the code Ptolemy during his visit there. Thanks are also due to Mr. H. Folger (GSI, Germany) for supplying the targets. This work was supported in part by China National Nature Science Fundation. 相似文献
998.
999.
1000.
We show for the first time that a classical Hookean viscoelastic constitutive law for rubbery materials can predict the impact forces and deflections measured with a commercial drop tester when a mass, or tup with a flat impacting surface is dropped onto a flat pad of commercial impact-absorbing rubber. The viscoelastic properties of the rubber, namely the relaxation times and strengths, are obtained by a standard rheological linear-oscillatory test, and the equation of momentum transfer is then solved, using these measured parameters, assuming a uniaxial deflection of the pad during the impact. Good agreement between measured and predicted forces and deflections is obtained for a series of various drop heights, tup masses, impact areas, and pad thicknesses, as long as the deflection of the pad relative to its thickness is small or modest (<50% or so), and as long as the area of the pad is less than or equal to that of the tup. When the pad area is greater than the tup, forces are higher than predicted, unless an empirical factor is introduced to account for the nonuniaxial stretching of the ring of material that extends outside of the impact area. These results imply that the impact-absorbing properties of a rubbery polymeric material can be assessed by simply examining the material's linear viscoelastic spectrum. 相似文献