排序方式: 共有42条查询结果,搜索用时 343 毫秒
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The paper deals with the existence of positive solutions of the singular equation u" f(t, u) = 0 with the linear boundary condition. We obtain the existence results of positive solution by means of the cone theory and the fixed point index. 相似文献
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HAMILTONIAN STRUCTURE AND INFINITE NUMBER OF CONSERVATION LAWS FOR THE COUPLED DISCRETE KdV EQUATIONS 总被引:1,自引:0,他引:1
YangHongxiang XuXixiang 《高校应用数学学报(英文版)》2004,19(4):374-380
A new discrete isospectral problem is introduced, from which the coupled discrete KdV hierarchy is deduced and is written in its Hamiltonian form by means of the trace identity.It is shown that each equation in the resulting hierarchy is Liouville integrable. Furthermore,an infinite number of conservation laws are shown explicitly by direct computation. 相似文献
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By the fxed point index theory, the existence of one, two and three positive solutions to(k, n-k) conjugate boundary value problems is obtained, where n > 2, 1 ≤ k ≤ n-1, the nonlinear term may be noncontinuous and singular at any point of [0,1]. Our results extend some of the existent results. 相似文献
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XuFenglin 《高校应用数学学报(英文版)》2000,15(1):99-108
Abstract. The averaging in optimal switching control problems is considered under the following two cases: the switching cost does not depend on e and the switching cost vanishes as e tends to zero. The value function of the original fast problem converges locally uniformly to the value function of the averaged problem under both cases. The ways of averaging turn out to be different between both cases. 相似文献
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A generalization of the direct method of Clarkson and Kruskal for finding similarity reductions of partial differential equations with arbitrary functions is found and discussed for the generalized Burgers equation. The corresponding reductions and the exact solutions due to the methods of the ordinary differential equations are then given by the methods. The results given here answer partially an open problem proposed by Clarkson, that is how to develop the direct method to seek symmetry reductions of nonlinear PDEs with arbitrary functions. 相似文献
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Wang Shiming 《分析论及其应用》1994,10(2):17-23
In this paper we consider the approximation for functions in some subspaces of L2 by spherical means of their Fourier integrals and Fourier series on set of full measure. Two main theorems are obtained.
Supported by NNSFC. 相似文献
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本文给出了Sasakian流形中反不变极小子流形是稳定或不稳定的一个充分条件. 相似文献