微腔中光强崩塌-回复特性的研究

本文研究了高-Q微腔中两能级原子集体激发辐射光强的崩塌-回复。使用Secular近似,给出了对于激子粒子敷态和相干态情况下,微腔中光强的解析表达式。同时,得到了回复时间很大程度上依赖于原子极化子数、失谐以及原子与场之间的耦合常数的结论。     

Quantum chemical study on the catalytic mechanism of Na/K on NO-char heterogeneous reactions during the coal reburning process

Quantum chemical simulation was used to investigate the catalytic mechanism of Na/K on NO-char heterogeneous reactions during the coal reburning process. Both NO-char and NO-Na/K reactions were considered as three-step processes in this calculation. Based on geometry optimizations made using the UB3LYP/6-31G（d） method, the activation energies of NO-char and NO-Na/K reactions were calculated using the QCISD（T）/6-311G（d, p） method; Results showed that the activation energy of the NO-Na/K reaction （107.9/82.0 kJ/mol） was much lower than that of the NO-char reaction （245.1 kJ/mol）. The reactions of NaO/KO and Na2O/K2O reduced by char were also studied, and their thermodynamics were calculated using the UB3LYP/6-31G（d） method; Results showed that both Na and K can be refreshed easily and rapidly by char at high temperature during the coal reburning process. Based on the calculations and analyses, the catalytic mechanism of Na/K on NO-char heterogeneous reactions during the coal reburning process was clarified.     

基于液相ZnSe量子点光源的光学层析成像系统

提出一种离散化的光学层析成像方法用于提取检测物的纵向深度信息和光谱特性。利用液相的ZnSe量子点为光源,设计了分立的元件组成光学层析装置,提取了多层媒质的信息。在理论上分析了模型的有效性;在实验上,利用五层媒质验证了该方法的可行性。基于此方法的研究可以广泛地应用于光学成像、生物芯片等许多领域。     

数字图书馆存储技术分析

针对现在数字图书馆的海量数据存储的现状和需求,构建一个安全、高效的存储后台已经成为数字图书馆建设中的重要任务。本文介绍了数字图书馆的存储体系架构(DAS、NAS、SAN和IP-SAN),并进行了全面的比较分析,指出了适用的图书馆类型,并提出结合了SAN与NAS的IPStorage是未来存储的发展趋势。     

量子信息技术--量子密钥

本介绍了量子技术在当今发展中的一个重要分支——量子密码学的发展动态，并以BB84量子协议为例进行了介绍。     

Hans bethe, quantum mechanics, and the lamb shift

An elementary derivation of the Lamb Shift, as originally given by Hans Bethe, is attempted, with a short historical background on the evolution of QED since the beginning of the last century. The treatment is for a non-relativistic electron, in keeping with Bethe’s proverbial insight into the problem, which renders irrelevant the effect of the electron spin on the problem. The Kramer idea of renormalization is implemented through a simple subtraction of the self-energy of a free electron from that of the electron bound in a hydrogen atom. A N Mitra has had a long teaching service from 1955 to 1994 when he retired from Delhi University as INSA Einstein Professor of physics. He spent a year (1995) as visiting professor at NIAS (Bangalore). Since then he has been working as a free-lance writer-cum-researcher in physics, with periodic publications on scientific matters of current interests. Concern for man and his fate must always form the chief interest of all technical endeavors. Never forget this in the midst of your diagrams and equations.     

霍尔效应的量子力学定性讨论

考虑到带电粒子在电磁场中的运动,利用量子力学原理定性地解释了霍尔效应.讨论了Lorentz 力和电力平衡下量子行为.通过推导沿着外场方向的平均速率,推演了宏观霍尔系数.     

普朗克量子假设

经典统计理论应用到热辐射时发现理论与实际不符合。为了克服这个困难,普朗克(Planck)在1900年引入了量子假设。本文较详细地讨论了经典统计理论如何与实际不符及普朗克又如何克服了这个困难。