Pseudo Almost Periodic Solutions of Nonlinear Hyperbolic Equations with Piecewise Constant Argument

In this paper, we investigate the pseudo almost periodicity of the unique bounded solution for a nonlinear hyperbolic equation with piecewise constant argument. The equation under consideration is a mathematical model for the dynamics of gas absorption,     

用不变量方法求含时谐振子的波函数

利用辅助方程从含量谐振子的哈密量出发得到了两个不变量，利用这两个不变量求得了系统薛定谔方程的解。     

一类具有逐段常变量神经网络系统概周期解存在性与指数稳定性

利用Halanay不等式,我们得到了一类具有逐段常变量神经网络系统解全局指数稳定的一个充分条件;此外,在同样条件下,通过不动点定理,证明了这类概周期系统概周期解的存在唯一性与模包含关系．     

有负顾客的M/G/1有限源重试排队系统

采用补充变量法，本文研究了有负顾客的M/G/1有限源重试排队系统。与前人的研究相比，本文考虑了干预因素，即负顾客对系统的影响，其中负顾客的机制是带走系统中所有正顾客。文中给出了两种解决系统微分方程组的递归方法，得到了重试组的平均人数，平均等待时间，系统忙期和工作周期分布的L变换等重要指标的递归公式。在特殊情况下，求出以上指标的具体表达式并得到与前人一致的结果。     

介绍一本好书《医学多变量统计分析与统计软件》

最近由北京医科大学出版社出版出版的《医学多变量统计分析与统计软件》一书 ,为我国著名的统计学家孙尚拱教授所著。著者早年于复旦大学数学系毕业 ,此后数十年如一日地专注于医学多变量统计的教学、研究与应用 ,是一位就实避虚、不善言词却成绩斐然的学者。此书可以说是他的代表作。著者在前言中说 ,“统计学是一门极具‘艺术性’和‘灵性’的学科 ,在多变量统计工作中更是如此”。他认为“中医是古代经验性的多变量分析的结果”,“解释中医理论的最有效的工具应是现代的多变量统计”。我们从书中列举的那些理论联系实际的例子可以体会到 …     

二元混合连分式展开的混合差商极限方法

For a univariate function given by its Taylor series expansion,a continuedfraction expansion can be obtained with the Viscovatov's algorithm,as the limitingvalue of a Thiele interpolating continued fraction or by means of the determinantalformulas for inverse and reciprocal differences with coincident data points.In thispaper,both Viscovatov-like algorithms and Taylor-like expansions are incorporatedto yield bivariate blending continued expansions which are computed as the limitingvalue of bivariate blending rational interpolants,which are constructed based on sym-metric blending differences.Numerical examples are given to show the effectivenessof our methods.     

Variable Coefficient KdV Equation and the Analytical Diagnoses of a Dipole Blocking Life Cycle

A variable coefficient Korteweg de Vries （VCKdV） system is derived by considering the time-dependent basic flow and boundary conditions from the well-known Euler equation with an earth rotation term. The analytical solution obtained from the VCKdV equation can be successfully used to explain fruitful phenomena in fluid and other physical fields, for instance, the atmospheric blocking phenomena. In particular, a diploe blocking case happened during 9 April 1973 to 18 April 1973 read out from the National Center for Environmental Prediction/National Center for Atmospheric Research （NCEP/NCAR） reanalysis data is well described by the analytical solution.     

Energy Variable Slow Positron Beam Study of Li^＋-Implantation-Induced Defects in ZnO

ZnO films grown on sapphire substrates are implanted with lO0-keV Li ions up to a total dose of 1 × 10^16 cm^-2. Vacancy-type defects, mostly vacancy dusters, are observed by positron annihilation measurements after implantation. Upon annealing, they first have an agglomeration process which leads to the growth in the vacancy size. After anneling at about 500℃, vacancy clusters grow into microvoids, which is indicated by the positronium formation. With annealing temperature increases to above 500℃, the microvoids begin to recover, and finMly M1 the implantation-induced vacancy defects are removed at 1000℃. No Li nanoclusters can be observed after Li^＋ implantation.     

变量分离法与变系数非线性薛定谔方程的求解探索

把变量分离法应用于(1+1) 维非线性物理模型，构建了色散缓变光纤变系数非线性薛定谔方程的一类新的孤子解.作为特例，也得到了常系数非线性薛定谔方程的包络型孤子解，只是解的形式有点变化.     

Propagation of Cylindrical Waves in Media of Time-Dependent Permittivity

We present the propagation of cylindrical waves in the media whose permittivity varies with time abruptly or continuously. By the method of variable separation, we derive the general expression of electric field of TM-polarized waves in two-dimensional space with excitation of any point at any time. With this expression,the solution for a spatially and temporally distributed source can be obtained theoretically. The focusing of reflected waves in the cross section is shown when the media undergoes a sudden or continuous change. The wave propagation in time-invariant media can be considered as a special case of the media under exponential variance.