水下超声速细长锥型射弹超空泡形态的计算方法

采用理想可压缩流体无旋定常流动以及超空泡尾部Riabushinsky闭合方式假定,基于细长体理论和匹配渐近展开法,建立了描述水下超声速条件下细长锥型射弹超空泡流动的积分微分方程.求解得到了考虑压缩性影响的超空泡形态二阶近似解,改进了超空泡形态的计算精度.分析了超声速射弹高速冲击条件下流体压缩性对超空泡形态的影响.流体压...     

Random attractors for stochastic sine-Gordon lattice systems with multiplicative white noise

We study the asymptotic behavior of solutions to the stochastic sine-Gordon lattice equations with multiplicative white noise. We first prove the existence and uniqueness of solutions, and then establish the existence of tempered random bounded absorbing sets and global random attractors.     

广义高阶Bernoulli数,Gauss和及广义Kloosterman和(英文)

利用广义高阶Bernoulli数的性质及Dirichlet L-函数的均值定理,研究了Gauss和及广义Kloosterman和与广义高阶Bernoulli数的均值性质,并给出两个有趣的渐近公式.     

一类多因素HIV模型的研究

研究了一类多因素HIV模型.建立了一个标准型的DI模型,证明了无病平衡点的局部渐近稳定性和全局渐近稳定性.     

部分线性回归模型变窗宽一步局部M-估计

讨论了部分线性回归模型的变窗宽一步局部M-估计.用一步局部M-估计给出未知函数的估计,用平均方法给出参数估计.进一步通过两个引理证明一步M-估计的渐近正态性.所提出的方法继承了局部多项式的优点并且克服了最小二乘法缺乏稳健性的缺点.     

Asymptotic Property of Approximation to xαgnx by Newman Type Operators

The approximation of ｜x｜ by rational functions is a classical rationalproblem. This paper deals with the rational approximation of the function xasgnx, which equals ｜x｜ if α=1. We construct a Newman type operator rn（x） and show max｜x｜≤1{｜x^αsgnx-rn（x）｜}-Cn-α/2e-√2nα where C is a constant depending on α.     

复合马尔可夫二项模型的Gerber-Shiu折现罚金函数

本文研究复合马尔可夫二项模型的Gerber-Shiu折现罚金函数,得到了有条件和无条件的Gerber-Shiu折现罚金函数所满足的瑕疵更新方程.然后给出这些折现罚金函数的渐近表达式.     

ASYMPTOTIC STABILITY OF NONLINEAR NEUTRAL DIFFERENTIAL EQUATIONS WITH CONSTANT DELAYS:A DESCRIPTOR SYSTEM APPROACH

In this article,we establish some new delay-dependent and delay-independent stability criteria for all solutions to a nonlinear neutral differential equation,using Lyapunov-Krasovskii functional.     

THE INTERIOR LAYER SOLUTION TO NONLOCAL REACTION DIFFUSION EQUATIONS

An initial boundary value problem of semilinear nonlocal reaction diffusion equations is considered.Under some suitable conditions,using the asymptotic theory,the existence and asymptotic behavior of the interior layer solution to the initial boundary value problem are studied.     

Three‐point bending tests—Part I: Mathematical study and asymptotic analysis

The goal of this work is to study the static behaviour of a three‐dimensional elastic beam when is subjected to a three‐point bending test. In the first part, under suitable compatibility conditions on the applied forces and on the geometry of the beam, we will prove the existence of a unique solution for the associated contact elastic problem; these conditions of compatibility on the data come from the absence of a Dirichlet condition on the beam boundary. In the second part, we will study the asymptotic behaviour of this problem; in particular, we will deduce the one‐dimensional models associated with the displacement components, and we will give the existence and uniqueness of solution for them. Moreover, we will give an expression for the normal axial stress in the beam which is related to the modulus of rupture of brittle materials. In the final part of the work, we will deal with the regularity of the solution for the bending problem and we will prove some properties of the coincidence set. Copyright © 2011 John Wiley & Sons, Ltd.