同输入M/M/∞排队群的联合队长过程

本提出一个偏微分方程方法，用这一方法研究同输入M/M／∞排队群中的联合队长分布。在任意初始条件下，给出了瞬时联合队长分布的多元母函数，也讨论了稳态队长的联合分布及各排队系统之间的相关性。     

KTP晶体中一种特殊缺陷的研究

研究发现,在KTP晶体中有一特殊的区域,在这一区域内,KTP晶体的倍频效率明显增加,本文借助于透射同步辐射(SR)白光形貌方法,对这一区域进行了研究,发现在这区域内有一面缺陷,在这面缺陷处由于杂质的积累,使晶格发生了微小畸变,从而使KTP晶体的倍频效率增加,并根据消光规律确定了该缺陷的最大应变方向R=<010>。 关键词：     

多目标最优化的一种积分型实现算法

在文[1]中给出了求解多目标最优化的一种积分总极值的概念性算法．本文利用数论中的一致分布佳点集列，较为简便的得出了多目标最优化的积分总极值的实现算法和算法终止准则．并经过有关函数数值计算表明该算法是有效的，可用来求解多目标最优化问题的有效解．     

压缩真空场与原子非线性作用过程中的纠缠与消纠缠

用Von Neumann熵研究了附加克尔介质的压缩真空场与二能级原子依赖强度耦合相互作用量子体系的量子纠缠特性.讨论了初始压缩真空场的压缩度以及克尔非线性作用的强度对该量子体系纠缠特性的影响.结果表明，克尔介质的非线性作用的强弱可以改变体系量子纠缠的周期性；在初始压缩度较大（r=5）时，克尔介质的非线性作用可导致原子与场持续地处于最大纠缠态，无消纠缠态或持续地处于消纠缠态. 关键词： 压缩真空态 克尔介质 依赖强度耦合J-C模型 Von Neumann熵 量子纠缠     

因特网防御DoS攻击技术评述Ⅰ--攻击分类与特征·包过滤·攻击检测与防御

概述了因特网上DoS攻击的相应分类及基本特征，评述了包过滤、攻击检测及防御技术的最新成果．前一部分介绍了入口过滤、基于路由的过滤网和有效源地址强制协议．后一方面主要讨论了适合于检测攻击包的技术，介绍了新近提出的频谱分析方法和泛滥检测系统．简要评述了已有的防御SYN泛滥攻击的技术措施，介绍了Cisco的TCP拦截技术，提出了改进策略．     

Formation of 2,6-dioxabicyclo[3.3.0]-octa-3,7-dienes or multiply substituted o-benzoquinones from reactions of 1,4-dilithio-1,3-dienes with dimethyl oxalate

Reactions of 1,4-dilithio-1,3-dienes with dimethyl oxalates afforded multiply substituted o-benzoquinones or stereodefined 2,6-dioxabicyclo[3.3.0]-octa-3,7-dienes in good yields.     

Numerical analysis of the rotating viscous flow approaching a solid sphere

A numerical simulation is performed to investigate the flow induced by a sphere moving along the axis of a rotating cylindrical container filled with the viscous fluid. Three‐dimensional incompressible Navier–Stokes equations are solved using a finite element method. The objective of this study is to examine the feature of waves generated by the Coriolis force at moderate Rossby numbers and that to what extent the Taylor–Proudman theorem is valid for the viscous rotating flow at small Rossby number and large Reynolds number. Calculations have been undertaken at the Rossby numbers (R_o) of 1 and 0.02 and the Reynolds numbers (R_e) of 200 and 500. When R_o=O(1), inertia waves are exhibited in the rotating flow past a sphere. The effects of the Reynolds number and the ratio of the radius of the sphere and that of the rotating cylinder on the flow structure are examined. When R_o ? 1, as predicted by the Taylor–Proudman theorem for inviscid flow, the so‐called ‘Taylor column’ is also generated in the viscous fluid flow after an evolutionary course of vortical flow structures. The initial evolution and final formation of the ‘Taylor column’ are exhibited. According to the present calculation, it has been verified that major theoretical statement about the rotating flow of the inviscid fluid may still approximately predict the rotating flow structure of the viscous fluid in a certain regime of the Reynolds number. Copyright © 2004 John Wiley & Sons, Ltd.     

非球面最适球面的确定方法——三点法

根据非球面生产的实际情况．指出非球面最适球面的确定方法．详细分析最适球面的计算方法．并对一抛物面进行了实例计算，通过与最小二乘法的计算结果比较．指出该方法具有计算简单、与加工工艺过程相符合等特点。     

The primary investigation of optical-limiting effects of optical active phthalocyanine derivative TMBO-SiPc

The optical-limiting property of an optically active phthalocyanine derivative with different configuration in chloroform solution was measured at 532 nm with 10 ns pulses. The excited state absorption cross-section σ_ex of the derivative was determined with the Z-scan technique. The results showed that the phthalocyanine derivative possesses larger σ_ex than the ground state absorption cross-section σ₀, indicating that it is a material for reverse saturable absorption. And it is specially noticed that the change in the optically active configuration affects its optical-limiting property significantly.     

Quantum Phase Transition in Quasi-two-dimensional Heisenberg Antiferromagnet with Single-Ion Anisotropy

In the present paper, we investigate the quantum phase transition in a spatially anisotropic antiferrornagnetic Heisenberg model of S =1 with single-ion energy anisotropy. By using the Schwinger boson representation, we calculate the Gaussian correction to the critical value J⊥^c caused by quantum spin fluctuations. We find that, for the positive single-ion energy, a nonzero value of J⊥^c is always needed to stabilize the antiferromagnetic long-range order in this model. It resolves a difference among literature and shows clearly that the effect of quantum fluctuations may qualitatively change a result obtained by the mean-field theories on lower-dimensional systems.