OSCILLATION CRITERIA FOR A CLASS OF HIGHER ORDER NEUTRAL DIFFERENTIAL EQUATIONS

We establish a new oscillation condition for even order neutral type differential equation of the following formwhere f is continuous and exists 1 ≤ k ≤ m(?)(t) ≡ Tk(t), a, (?)i ∈ C([0, ∞], R), i = 1, …,m. such that 0 ≤ a(t) ≤ L and     

偶数阶时滞微分方程的单调解

使用一种新技巧,研究了两类偶数阶时滞微分方程的单调正解的存在任,得到了方程存在单调正解的一些充要条件和充分条件。     

Isospin Effect of Coulomb Interaction on Momentum Dissipation in Intermediate Energy Heavy Ion Collisions

We investigate the isospin effect of Coulomb interaction on the momentum dissipation or nuclear stopping in the intermediate energy heavy ion collisions by using the isospin-dependent quantum molecular dynamics model. The calculated results show that the Coulomb interaction induces obviously the reductions of the momentum dissipation. We also find that the variation amplitude of momentum dissipation induced by the Coulomb interaction depends sensitively on the form and strength of symmetry potential. However, the isospin effect of Coulomb interaction on the momentum dissipation is less than that induced by the in-medium nucleon-nucleon cross section.In this case, Coulomb interaction does not change obviously the isospin effect of momentum dissipation induced by the in-medium two-body collision. In particular, the Coulomb interaction is preferable for standing up the isospin effect of in-medium nucleon-nucleon cross section on the momentum dissipation and reducing the isospin effect of symmetry potential on it, which is important for obtaining the feature about the sensitive dependence of momentum dissipation on the in-medium nucleon-nucleon cross section and weakly on the symmetry potential.     

随机利率下增额寿险现值函数矩的一些结果

本文对随机利率采用 Wiener过程和 Orentein- Uhlenbeck过程建模 ,得到了增额寿险现值函数的矩的一些结果     

随机右删失下回归函数的正态逼近

在随机右删失下，我们考虑了模型Yi=g(xi) εi，1≤i≤n．当εi's不服从正态分布时。我们构造了g(x)的估计式gn^(x)，并且利用强逼近的结论，导出了gn^(x)-Eg^n(x)的正态逼近结果，得到了较快的收敛速度。     

ON COMPUTATIONS OF STRESS INTENSITY FACTORS FOR STIFFENED HALF PLANES WITH IMPERFECTIONS AND CRACKS

In this paper we consider uniform extension problems for joined two half-planes withdifferent thickness and material behavior and one of which contains an elliptical hole,theother contains a crack.Along the boundary of these half-planes there is a stiffeningstringer.Computational formulas are given in power series form by complex variable—pertubation method.Results obtained here give extension to those of "Handbook of stressintensity factors".Numerical results of special cases in this paper coincide with those ofrefs.[1],[3].     

固体力学基础

《固体力学培础》(Foundation of Solid Mechanics 1965,Prentice-Hall)是论述现代固体力学理论基础的专门著作,它的著者是蒋铝美藉中国力学家冯元桢教授,该书系冯教授在加州理工学院给研究生讲授该课程时,撰写的力学教科书. 本忆侧重固体力学一般方法论的阐述,其突出特点是将深刻的物理、力学内容与正确     

金(I)化合物中的亲金相互作用

20世纪80年代,人们发现在金(I)化合物的金原子之间存在某种相互作用,并称之为亲金相互作用。通过对这类化合物的深入研究,目前人们已经可以解释它们的形成原因、作用机理,以及理论依据。本文综述了亲金相互作用的发现、历史进展、典型实例,介绍了它们在物理、化学领域中的最新进展和应用。     

非线性断裂力学

“非线性断裂力学”,系由美国应用力学系著名断裂专家J.W.Hutchinson教授所著,该书于1979年由丹麦理工大学固体力学系出版。 Hutchinson教授是非线性理论的开拓者之一,他对这一领域的精深研究使他成为第十五届国际理论和应用力学大会在该领域的特邀专题报告人。