相空间中二阶线性非完整系统的形式不变性

研究相空间中二阶线性非完整系统的形式不变性.给出相空间中二阶线性非完整系统形式不变性的定义和判据，得到形式不变性的结构方程和守恒量的形式，并举例说明结果的应用. 关键词： 相空间 二阶线性非完整系统 形式不变性 守恒量     

利用模拟方法研究RFQ加速器中正、负离子束同时加速的动力学问题

在以时间为自变量的PARMTEQ程序的基础上,添加了另一带相反电荷的束流进行动力学计算,同时考虑了正、负离子束加速的空间电荷效应和束团间的作用.并针对特定结构参数的RFQ加速器,给出了双束加速的动力学模拟过程和结果.模拟计算的目的在于研究正、负离子束在RFQ加速结构中同时加速所引起的动力学问题.结果表明,正、负离子束同时加速有助于克服径向空间电荷效应,但在流强较大时,双束加速时,将会在纵向出现明显的异性电荷之间的“捕捉”(trap)现象,从而导致纵向粒子损失数目的增加.因此,为实现双束加速,必须专门重新设计RFQ加速器,使其传输效率高于单束,才能体现出双束加速的优越性     

对柱对称电流分布磁矢势问题的讨论

采用柱对称性和叠加原理讨论了均匀载流圆环、圆筒、圆盘的矢势问题．     

拓扑缺陷的不同分布对单壁碳纳米管电学性能的影响

在紧束缚近似基础上,利用扩展的Su-Schriffer-Heeger(SSH)模型,在实空间研究了在完整的"zigzag"碳纳米管中分别引入5/7,5/6/7,5/6/6/7拓扑缺陷所构成的(9,0)-(8,0),(9,0)-(7,0)和(9,0)-(6,0)三种异质结的电学性能.通过研究表明:这些拓扑缺陷不仅改变碳管的直径,而且支配费米能级附近的电学行为.并计算了(9,0)-(8,0),(9,0)-(7,0)和(9,0)-(6,0)系统的电子态密度,对这3种异质结的能带结构和电子态密度进行了比较.结果表明:五边形和七边形在碳管中分布的不同对碳管电学性能的影响明显不同.因此,可以研制出基于这些异质结的不同的电子器件基元.     

"神舟"五号的空间环境保障

空间环境安全保障是载人航天器飞行安全和航天员生命安全保障的一个重要部分．文章从高层大气、高能辐射环境、流星体空间碎片和重大空间环境扰动事件等四个方面空间环境要素对载人航天的影响，介绍了空间环境预报中心为“神舟”五号载人飞行任务所作的空间环境保障工作．     

Model reduction of state space systems via an implicitly restarted Lanczos method

The nonsymmetric Lanczos method has recently received significant attention as a model reduction technique for large-scale systems. Unfortunately, the Lanczos method may produce an unstable partial realization for a given, stable system. To remedy this situation, unexpensive implicit restarts are developed which can be employed to stabilize the Lanczos generated model.This work was supported in part by ARPA (US Army ORA4466.01), by ARPA (Grant 60NANB2D1272), by the Department of Energy (Contract DE-FG0f-91ER25103) and by the National Science Foundation (Grants CCR-9209349 and CCR-9120008).     

Carleson measure characterization of Bloch functions

We give several equivalences of Bloch functions and little Bloch functions. Using these results we obtain the generalized Carleson measure characterization of Bloch functions and the generalized vanishing Carleson measure characterization of little Bloch functions, that is,f B if and only if |D f(z)| ^p (1-|z|²)^p-1 dm(z) is a generalized Carleson measure;f B ₀ if and only if |D f(z)| ^p (1-|z|²)^p-1 dm(z) is a generalized vanishing Carleson measure, whereD f( > 0) is the fractional derivative of analytic functionf of order, m denotes the normalised Lebesgue measure.Supported partly by the Young Teacher Natural Science Foundation of Shandong Province.     

An Arithmetic Reduction of Finite Rank 3 Geometries with Linear Spaces as Plane Residues and with Dual Linear Spaces as Point Residues

Let be a rank three incidence geometry of points, lines and planes whose planes are linear spaces and whose point residues are dual linear spaces (notice that we do not require anything on the line residues). We assume that the residual linear spaces of belong to a natural class of finite linear spaces, namely those linear spaces whose full automorphism group acts flag-transitively and whose orders are polynomial functions of some prime number. This class consists of six families of linear spaces. In the amalgamation of two such linear spaces imposes an equality on their orders leading, in particular, to a series of diophantine equations, the solutions of which provide a reduction theorem on the possible amalgams of linear spaces that can occur in .We prove that one of the following holds (up to a permutation of the words point and plane):A) the planes of and the dual of the point residues belong to the same family and have the same orders,B) the diagram of is in one of six families,C) the diagram of belongs to a list of seven sporadic cases.Finally, we consider the particular case where the line residues of are generalized digons.     

一个新的极大极小定理及应用

本文得到一个新的极大极小定理及其几个等价形式．作为这一结果的应用，我们得到区间空间上的Ｋｙ Ｆａｎ型截口定理，匹配定理和几个集值映象的不动点定理．     

幂向量,复合向量数及其函数理论

本文提出向量为其幂向量和向量幂级数．向量幂级数由一实数和某一向量联合组成的“复合向量数”及其函数有重要涵义．这数也有运算法则．从复合向量数的函数理论分析知其函数有导数和解析函数的必要和充分条件．这些条件构成了“双曲型”方程的特征以及函数的积分性质等．