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991.
In the present paper we establish Lyapunov type integral inequalities related to the zeros of solutions of certain second-order differential equations by using elementary analysis. We also present some immediate applications of our results to study the asymptotic behavior of solutions of the corresponding differential equations. 相似文献
992.
Hongya Gao 《Journal of Mathematical Analysis and Applications》2003,281(1):253-263
We first prove a local weighted integral inequality for conjugate A-harmonic tensors. Then, as an application of our local result, we prove a global weighted integral inequality for conjugate A-harmonic tensors in Ls(μ)-averaging domains, which can be considered as a generalization of the classical result. Finally, we give applications of the above results to quasiregular mappings. 相似文献
993.
Direct and inverse problems of oscillations of an anisotropic layer with a cylindrical cavity of an arbitrary cross-sectional
shape under the action of a load applied to the layer surface are considered. An asymptotic approach to solving these problems
with cavities of small relative sizes is proposed. Numerical results of solving direct and inverse problems are presented.
__________
Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 50, No. 3, pp. 181–189, May–June, 2009. 相似文献
994.
李殿龙 《数学的实践与认识》2008,38(8):143-146
研究迷向子群的结构是有限域上典型群几何中的一个重要问题.刻画了3-幂零矩阵的Jordan标准型在GLn(F)共轭作用下的迷向子群的结构. 相似文献
995.
This paper presents exact solutions in terms of implicit functions and hyperbolic functions to a nonconvex dissipative system,
controlled by a Duffing–van der Pol nonlinear equation with a fifth-order nonlinearity. Applications to the complex Ginzburg–Landau
equation are illustrated and several classes of uniformly translating solutions are obtained accordingly.
Part of the work was announced at the International Conference on Complementarity, Duality, and Global Optimization in Science
and Engineering, Virginia Tech. University, Blacksburg, Virginia, August 15–17, 2005. This work is supported by NSF Grant
CCF–0514768. 相似文献
996.
M. Yu. Kokurin S. K. Paimerov 《Computational Mathematics and Mathematical Physics》2008,48(1):109-120
The nonlinear inverse problem for a wave equation is investigated in a three-dimensional bounded domain subject to the Dirichlet boundary condition. Given a family of solutions to the equation defined on a closed surface within the original domain, it is required to reconstruct the coefficient determining the velocity of sound in the medium. The solutions used for this purpose correspond to the acoustic medium perturbations localized in the neighborhood of a certain closed surface. The inverse problem is reduced to a linear integral equation of the first kind, and the uniqueness of the solution to this equation is established. Numerical results are presented. 相似文献
997.
This paper considers the problems of determining center or focus and isochronous centers for the planar quasi-analytic systems.
Two recursive formulas to determine the focal values and period constants are given. The convergence of first integral near
the center is proved. Using the general results to quasi-quadratic systems, the problem of the isochronous center of the origin
is completely solved.
This research is partially supported by the National Natural Science Foundation of China (10671179 and 10771196) and the Natural
Science Foundation of Yunnan Province (2005A0092M) 相似文献
998.
设Bm(f,·)为函数f在d维单纯形σ上的n阶Bernstein多项式,本文对f∈Cr(σ)及f∈Cr+2(σ)给出了f的各阶编导数用Bn(f,·)相应偏导数逼近的误差估计.同时也考虑了整系数Bernstein多项式的Lp模估计 相似文献
999.
A. Dagan 《国际流体数值方法杂志》1988,8(8):943-955
A method for computing the drag coefficient of a body in an axially symmetric, steady-state cavitation flow is presented. A ‘vortex ring’ distribution along the wetted body surface and along the cavity interface is assumed. Since the location of the cavitation interface is unknown a priori, an iterative procedure is used, where, for the first stage, an arbitrary cavitation interface is assumed. The flow field is then solved, and by an iterative process the location of the cavitation interface is corrected. Even though the flow field is governed by the linear Laplace equation, strong non-linearity resulting from the kinematic boundary conditions appears along the cavitation interface. An improved numerical scheme for solving the dual Fredholm integral equations is obtained by formulating high-order approximations to the singular integrals in order to reduce the matrix dimensions. Good agreement is found between the numerical results of the present work, experimental results and other solutions. 相似文献
1000.
谭维翰 《核聚变与等离子体物理》1985,(2)
众所周知,将玻耳兹曼积分应用于等离子体,由于忽略了集体效应,导致积分对数发散。另外,Balescu-Lenard碰撞理论考虑了集体效应,克服了k→0对数发散困难,但又有k→0积分发散。对于等离子体参量g=1/nλD~3《1情形,文[4]已得出克服k→0积分发散的方法。但对g≥1情形,k→0积分发散问题仍未解决。本文改进了粒子分布函数展开求得包括g<1及g≥1在内的一般情形即南k→0与k→0均收敛的碰撞积分。 相似文献