双折射滤光片的色散特性研究

研究了由理想线偏振片和单轴双折射晶体波片组成的双折射滤光片倾斜放置时的二阶色散和 三阶色散特性，包括波片厚度、光线入射角和光轴旋转角的变化对二阶和三阶色散的影响. 还给出了双折射滤光片的群延迟表达式，并就色散特性与GT干涉仪进行了详细比较. 关键词： 双折射滤光片 群延迟 二阶色散 三阶色散     

量子算法的NMR实现方法

量子计算机是一种以量子耦合方式进行信息处理的装置[1 ] 。原则上 ,它能利用量子相干干涉方法以比传统计算机更快的速度进行诸如大数的因式分解、未排序数据库中的数据搜索等工作[2 ] 。建造大型量子计算机的主要困难是噪音、去耦和制造工艺。一方面 ,虽然离子陷阱和光学腔实验方法大有希望 ,但这些方法都还没有成功实现过量子计算。另一方面 ,因为隔离于自然环境 ,核自旋可以成为很好的“量子比特” ,可能以非传统方式使用核磁共振 (NMR)技术实现量子计算。本文介绍一种用NMR方法实现量子计算的方法 ,该方法能够用比传统方法少的步骤解决一个纯数学问题。基于该方法的简单量子计算机使用比传统计算机使用更少的函数“调用”判断一未知函数的类别。     

Von Neumann Entropy of an Electron in One-Dimensional Determined Potentials

By using the measure of von Neumann entropy, we numerically investigate quantum entanglement of an electron moving in the one-dimensional Harper model and in the one-dimensional slowly varying potential model. The delocalized and localized eigenstates can be distinguished by von Neumann entropy of the individual eigenstates.There are drastic decreases in von Neumann entropy of the individual eigenstates at mobility edges. In the curve of the spectrum averaged von Neumann entropy as a function of potential parameter λ, a sharp transition exists at the metal-insulator transition point λc = 2. It is found that the von Neumann entropy is a good quantity to reflect localization and metal-insulator transition.     

Multiparty Quantum Secret Sharing of Key Using Practical Faint Laser Pulses

Based on a bidirectional quantum key distribution protocol [Phys. Rev. A 70 (2004)012311], we propose a (m-1, m-1)-threshold scheme of m (m≥3)-party quantum secret sharing of key by using practical faint laser pulses. In our scheme, if all the m-1 sharers collaborate, they can obtain the joint secret key from the message sender. Our scheme is more feasible according to the present-day technology.     

分布式协同关联入侵检测系统及关联语言

提出了一种完全非集中方式，将入侵建模为发生在被保护网络系统中多个节点上的事件序列，部署的各协同关联引擎自动关联入侵证据，从而得到高层的全局告警．本文为这种模式提出了一种基于XML的分布式协同关联入侵检测描述语言．     

西藏区域经济系统的灰色关联分析

区域经济的发展受许多不同因素的影响，本结合西藏社会经济发展的特点，选取了总产值指标、第一产业指标、第二产业指标和第三产业指标等四大类指标体系，采用灰色关联分析法对西藏的区域经济系统进行了简要的分析评价，以研究西藏区域经济的发展状况，从社会经济的角度探讨西藏经济发展落后的原因，以期能为西藏经济发展政策提供参考依据。     

Experimental Creation of Entanglement Using Separable States

We experimentally demonstrate that the entanglement can be created on two distant particles using separable states. We show that two working particles can share some entanglement, while one ancilla particle always remains separable from the two working particles during the experimental evolution of the system. Our experiment can be viewed as a benchmark to illustrate the idea that no prior entanglement is necessary to create entanglement.     

一种有机电致发光共聚物的制备和性能

采用Suzuki方法合成了9，9-二辛基芴与萘并硒二唑的两种无规共聚物并研究了其紫外光谱、光致发光和电致发光性能。两种聚合物的电致发光波长为650～666nm，均为发饱和红光的LED材料，其电致发光外量子效率最高达到了1．05％。随着共聚物中萘并硒二唑含量的增加，共聚物的光致发光和电致发光的发射波长均有少量红移。证明了根据共轭高聚物链内能量转移原理，在聚芴链中引入不同含量的窄带隙杂环单元可实现对聚芴发光颜色的调节。     

原子钟、原子弹哪个更重要

 1945年原子弹(AtomicBomb)在广岛长崎爆炸之前,一般人很难理解原子弹的威力,原子钟(AtomicClock)也不是大家都能一睹为快的;但是,原子弹和原子钟的概念的确已是家喻户晓。如果我们要比较原子钟和原子弹谁更重要还真不容易,原因很简单:它们自从诞生之日起,就对世界产生了极其深远的影响;而且,随着时间的推移,这种影响不是在减弱,而是在日益加剧。从理性上来讲,原子钟的贡献并不比原子弹小,也并不让人毛骨悚然。我们认为,原子钟给人类的贡献要远远大于原子弹,而且,在社会和科学研究中日益发挥着更为重要的作用.     

Theoretical Analysis of Characteristics of GaxInl—x NyAsl—y／GaAs Quantum Well Lasers with Different Intermediate Layers

Based on the band anticrossing model, the effects of the strain-compensated layer and the strain-mediated layero n the band structure, gain and differential gain of GalnNAs/GaAs quantum well lasers have been investigated. The results show that the GaNAs barrier has a disadvantage in increasing the density of states in the conduction band. Meanwhile, the multilayer quantum wells need higher transparency carrier density than the GalnNAs/GaAs single quantum well with the same wavelength. However, they help to suppress the degradation of the differential gain. The calculation also shows that from the viewpoint of band structure, the strain-compensated structure and the strain-mediated structure have similar features.