1+1维抛射沉积模型内部结构动力学行为的数值研究

采用Kinetic Monte Carlo方法对1+1维抛射沉积(BD)模型内部结构的动力学行为进行了大量的数值模拟研究.分别分析了空洞密度和内部界面的动力学行为.研究表明,空洞密度呈高斯型分布,其平均值首先随生长时间快速增长,然后达到一个与基底尺寸无关的饱和值.除表面宽度,还引入了新的极值统计方法来分析该模型内部界面的动力学行为,分析结果显示,1+1维BD模型内部界面的演化满足标准的Family-Vicsek标度规律,并且属Kardar-Parisi-Zhang方程所描述的普适类.最后对表面宽度和极值统计两种理论方法的有限尺寸效应进行了比较.     

分数布朗运动和反常扩散

本文评述了分数布朗运动和反常扩散现象及描写它们的几种数学方式。报告了我们在弹道扩散的产生条件、起源和长时间效应方面的工作。     

天基监视雷达

介绍了天基雷达的三种类型：第一种交会雷达、第二种遥感卫星上的合成孔径雷达(SAR)成像雷达、第三种天基监视雷达，该雷达目前正在大力开发。重点讨论对天基监视雷达的设计要求和具体设计技术。     

Parallel computation of two-point boundary-value problems via particular solutions

Nonlinear two-point boundary-value problems (TPBVP) can be reduced to the iterative solution of a sequence of linear problems by means of quasilinearization techniques. Therefore, the efficient solution of linear problems is the key to the efficient solution of nonlinear problems.Among the techniques available for solving linear two-point boundary-value problems, the method of particular solutions (MPS) is particularly attractive in that it employs only one differential system, the original nonhomogeneous system, albeit with different initial conditions. This feature of MPS makes it ideally suitable for implementation on parallel computers in that the following requirements are met: the computational effort is subdivided into separate tasks (particular solutions) assigned to the different processors; the tasks have nearly the same size; there is little intercommunication between the tasks.For the TPBVP, the speedup achievable is ofO(n), wheren is the dimension of the state vector, hence relatively modest for the differential systems of interest in trajectory optimization and guidance. This being the case, we transform the TPBVP into a multi-point boundary-value problem (MPBVP) involvingm time subintervals, withm–1 continuity conditions imposed at the interface of contiguous subintervals. For the MPBVP, the speedup achievable is ofO(mn), hence substantially higher than that achievable for the TPBVP. It reduces toO(m) if the parallelism is implemented only in the time domain and not in the state domain.A drawback of the multi-point approach is that it requires the solution of a large linear algebraic system for the constants of the particular solutions. This drawback can be offset by exploiting the particular nature of the interface conditions: if the vector of constants for the first subinterval is known, the vector of constants for the subsequent subintervals can be obtained with linear transformations. Using decomposition techniques together with the discrete version of MPS, the size of the linear algebraic system for the multi-point case becomes the same as that for the two-point case.Numerical tests on the Intel iPSC/860 computer show that substantial speedup can be achieved via parallel algorithms vis-a-vis sequential algorithms. Therefore, the present technique has considerable interest for real-time trajectory optimization and guidance.Dedicated to the Memory of Professor Jan M. SkowronskiThis paper, based on Refs. 1–3, is a much condensed version of the material contained in these references.The technical assistance of the Research Center on Parallel Computation of Rice University, Houston, Texas is gratefully acknowledged.     

行波管电子光学系统CAD技术进展

介绍了行波管电子光学系统CAD技术的基本原理和主要方法，并对国内外的发展进行了综述，同时分析了当前该领域的发展方向，为我国自主开发行波管电子光学系统软件提供一些建议供同行们参考。     

导弹末区轨迹的单站定位测量

通过对导弹末区轨迹单站定位测量方法所采用的位置测量方程和速度加速度测量方程的推导,介绍了导弹末区轨迹的单站定位测量原理。系统误差分析结果表明,影响导弹末区轨迹测量精度的主要因素是测量设备的方位角和俯仰角测量误差,而不是通常认为的激光测距误差。通过单站定位测量法与多站交会测量法之间的性能比较,论述了单站定位测量法的技术优势。     

Cl+HD反应产物的极化与态分布

利用准经典轨线理论 ,在BW 2和G3两个势能面上 ,研究了Cl +HD反应的动力学 .计算结果表明 ,产物的转动取向对势能面及反应体系的质量因子非常敏感 .在BW 2势能面上 ,计算的两个产物的转动取向强于在G3势能面上计算的结果 ,而无论是在BW 2势能面上还是在G3势能面上 ,DCl产物的取向都强于HCl产物的取向 .计算结果还表明 ,在不同的势能面上反应物的转动激发对反应的影响有着显著的不同 .在BW 2势能面上 ,反应物的初始转动激发有利于Cl+HD反应的进行 ;而在G3势能面上 ,反应物的初始转动激发消弱了反应的反应性     

中段目标进动雷达特征提取

本文总结了弹道导弹目标雷达识别的研究现状,推导了进动锥体目标对雷达波的姿态角计算公式,分析了目标RCS和姿态角的关系,使用进动锥体目标的RCS时间序列估计了目标进动参数和惯量比,使用惯量比作为特征,提出了识别弹头和诱饵的方法,最后给出了仿真结果。     

Banach空间中微分包含的生存单调轨道与解的稳定性

我们在无限维空间中研究微分包含的生存W—单调轨道的存在性．基于Zorn引理，我们给出了一个逼近方法，在较弱的条件下得到了一个存在性定理，其特殊情形则包含了已有的生存定理和微分方程理论中的若干结果作为应用，我们首先研究了微分包含生存解的整体存在性，得到了整体生存理．然后我们研究了微分包含解的稳定性，得到一些新的结果．     

一种分析雾中成像的新方法

从理论上分析了载有物像信息的子弹光在烟雾介质中传播时强度的变化及极限传输距离，提出了一种基于光偏振特性验证该理论的新实验方法，其实验结果与理论分析一致，并讨论了利用该实验装置在实际雾中成像场合下改善信噪比、提高成像质量的可能性