A new variable coefficient algebraic method and non-travelling wave solutions of nonlinear equations

In this paper, a new auxiliary equation method is presented of constructing more new non-travelling wave solutions of nonlinear differential equations in mathematical physics, which is direct and more powerful than projective Riccati equation method. In order to illustrate the validity and the advantages of the method, （2＋1）-dimensional asymmetric Nizhnik-Novikov-Vesselov equation is employed and many new double periodic non-travelling wave solutions are obtained. This algorithm can also be applied to other nonlinear differential equations.     

Periodic solutions and flip bifurcation in a linear impulsive system

In this paper, the dynamical behaviour of a linear impulsive system is discussed both theoretically and numerically. The existence and the stability of period-one solution are discussed by using a discrete map. The conditions of existence for flip bifurcation are derived by using the centre manifold theorem and bifurcation theorem. The bifurcation analysis shows that chaotic solutions appear via a cascade of period-doubling in some interval of parameters. Moreover, the periodic solutions, the bifurcation diagram, and the chaotic attractor, which show their consistence with the theoretical analyses, are given in an example.     

微型数据采集器及其在加速器周围辐射场实时监测中的应用

各种类型加速器周围的辐射场变化是很复杂的,只有对其进行连续的实时监测才能准确地掌握全面资料.以往的数据采集系统用的是模拟信号长距离传输方式,采集器体积较大,存储技术上也显落后,已不能适应当今的需求.为辐射场实时监测研制的微型数据采集器采用了先进的设计理念,具有体积小、通讯能力强、数据存储量大且断电数据不丢失的特点,可运行于局域网环境.它既可利用局域网远距离向控制计算机传递数据,也可用便携式PC通过串口就近读取数据.所以它不但适于固定场所的连续监测,也可灵活地用于临时测量场所.介绍了它的主要性能和在各类型加速器周围所做测量的结果.     

带跳的耦合正倒向随机微分方程

本文对带跳的耦合正倒向随机微分方程引入了"桥"的概念,证明了如果两个带跳的耦合正倒向随机微分方程被桥连接着,那么它们有相同的唯一可解性.在此基础上,通过桥的构造,得到一些带跳的正倒向随机微分方程的唯一可解性.     

Generation of 2.1 W Continuous Wave Blue Light by Intracavity Doubling of a Diode-End-Pumped Nd：YAG Laser in a 30 mm LBO

A folded four-mirror cavity with a composite Nd：YAG rod is optimized to obtain high efficient cw 473nm blue output. The laser could operate stably in the region of the thermal-lens focal length from 20mm to 70mm. LBO is used for intracavity frequency doubling of the 946nm transition of Nd：YAG and the optimum LBO length is investigated. A maximum output power of 2.1 Win the blue spectral range at 473nm is achieved with 30-mm-long LBO, corresponding to an optical conversion efficiency of 9.1%.     

一个跨音风扇级转/静干扰流动的时间精确模拟

本文采用双时间步法,较为方便地将孤立叶排定常流场求解拓广为转／静干扰非定常流场时间精确求解,而且该流场时间精确求解方法收敛速度较作者最初工作有较大提高．文章通过对一跨音风扇级非定常流场时间精确模拟,对叶轮机非定常流动建立了一定理解．     

一类捕食-被食系统的全局渐近稳定性

本文对如下形式的具分布时滞的捕食－被食系统：通过构造Ｌｉａｐｕｎｏｖ泛函,得到了该系统正平衡解全局渐近稳定的充分条件,所得结果包括了一些相关的已有结果为其特例。     

NEW EXACT TRAVELLING WAVE SOLUTIONS TO THREE NONLINEAR EVOLUTION EQUATIONS

Based on the computerized symbolic computation, some new exact travelling wave solutions to three nonlinear evolution equations are explicitly obtained by replacing the tanhξ in tanh-function method with the solutions of a new auxiliary ordinary differential equation.     

带Poisson跳随机微分方程终值与边值问题的适应解

Poisson跳的拟线性倒向随机微分方程x(t) ∫tf(s,x(s),,x(s)) y(s)]dMs =ξ,t∈[0,1],这里M = (W,Q)T,其中W为Wiener过程,Q为补偿Poisson过程.利用区间延拓和 Bihari 不等式证明了在某种弱于Lipschitz条件下方程存在唯一适应解,并给出了解的估计,从而将文章[1]的结论推广到带 Poission 跳的情形.另外,本文还讨论了以下形式的边值问题:dx(t) = f(t,x(t),y(t))dt y(t)dMt,Ax(0) Bx(1) =ξ*,t∈[0,1],并证明了在Lipschitz条件下适应解的存在唯一性.