Evolution of nonclassical light propagating through passive optical coupled waveguides: Entanglement dynamic

In this paper, nonclassical light propagation through passive optical coupler is investigated. On the other hand, passive optical device design for nonclassical light is analyzed in this work. Effect of mode mismatching including mismatching in propagation constant on operation of the considered device is studied. We investigate different separable and entangled input excitations with single photons in this case. We specially study the measure of entanglement and effect of propagation constant mismatch on it. The simultaneous effect of loss and mismatch is also studied. Obtained results for different excitation states illustrate that there is a possibility to design such that the system operation can be immune versus fabrication imperfections.     

二氟沙星在中性水溶液中的光化学性质(英文)

对二氟沙星在中性水溶液中的光化学性质进行了研究.在pH值为7.17的水溶液中二氟沙星的紫外吸收峰位于273 nm(摩尔消光系数ε=33000 dm3·mol-1·cm-1),323 nm(ε=15500 dm3·mol-1·cm-1),335 nm(ε=15500 dm3·mol-1·cm-1)处.荧光吸收和发射光谱均显示二氟沙星具有pH效应,其pKa(电离平衡常数)测定分别为5.9和9.8.二氟沙星的荧光量子产额较低,在pH=3.00时达到最大值,为0.06.同时对二氟沙星在中性水溶液中的激光光解和脉冲辐解进行详细研究.激光光解研究发现在水溶液中二氟沙星的三重激发态位于620nm,其摩尔消光系数为7900 dm3·mol-1·cm-1.通过能量转移的方法得到其三重激发态的能量为263.5 kJ·mol-1,三重激发态的量子产额为0.21.在激光激发下,二氟沙星进行单光子电离其量子产额为0.02.脉冲辐解研究表明二氟沙星可以与水合电子(e-aq)及羟基自由基(·OH)快速反应,其二级反应动力学常数分别为1.72×1010和1.0×1010dm3·mol-1·s-1.本文对二氟沙星光化学性质的研究有助于确定其光敏毒性的产生机理.     

黄芩素激发态分子内质予转移耦合电荷转移反应的实验和理论研究

通过稳态光谱实验和量子化学计算相结合,研究了黄芩素激发态质子转移耦合电荷转移的反应. 实验和计算中S1态吸收峰的缺失表明S1态是暗态. S1暗态导致在实验中观察不到黄芩素在乙醇溶液中的荧光峰,且固体的荧光峰很弱. 黄芩素分子的前线分子轨道和电荷差异密度表明S1态是电荷转移态,然而S2态是局域激发态. 计算的黄芩素分子的势能曲线在激发态只有一个稳定点,这表明了黄芩素激发态分子内质子转移的过程是一个无能垒的过程.     

环境法的定位及其法典化

从历史维度看,环境法从有关环境保护的法迈向专门保护环境的法。在环境法的演进中,环境法因独立性存疑而倍受身份危机的困扰。环境法的危机源于其所调整的生态环境变化无常,这意味着环境法制必须具备较强的适应性：环境保护议程能够根据新的环境科学知识不断及时调整。从有效保护生态环境的角度看,环境法的定位应当从当下的实质法向未来的程序法转变,前者强调“向后看”−总结过去,后者突出“向前看” −面向未来。基于环境法的历史脉络及其合理定位,不难发现环境法法典化绝非易事,理性的环境法法典化应当以程序保障为中心而展开。     

激发压缩真空态的相位概率分布

应用Pegg和Barnett提出的相位算符和相位态理论,研究了激发压缩真空态的相位概率分布特性.数值计算结果表明,激发压缩真空态的相位概率分布主要受到相位参量和压缩参量的调节,相位参量使相位概率分布呈峰值结构,压缩参量的变化将影响相位概率分布的峰值强度,此外激发光子数对相位概率分布也有较大的影响.     

氖,硅和钛元素的类锂离子激发态参数的计算

为利用本所重离子加速器原子物理实验装置进行高电离态离子物理实验研究，本文采用郑能武等人＾［＾１＾］提出的最弱受约束电子势模型理论的波函数和Ｈ．Ａ．Ｂｅｔｈｅ等入＾［＾２＾］的量子力学理论，估算了Ｎｅ，Ｓｉ和Ｔｉ离子的类锂等电子序２Ｓ－２Ｐ态的跃迁几率和振子强度，并把计算结果与文献结果作了比较。     

分子轨道法（PPP－CI）计算芳烃化合物的荧光光谱及激发态结构

应用分子轨道法（ＰＰＰ－ＣＩ）计算了２５种芳烃化合物的基态和第一激发单重态的。电荷分布、偶极矩、键级，以及各分子轨道的能级分布的变化。计算得到的分子吸收光谱波长与实验值非常一致。发现计算得到的荧光辐射能△ＥＬ与荧光米谱波数ｖｆｌ；计算得到的分子激发过程中的平均键级变化△Ｐ与荧光量子产率φ存在如下关系：＝７．０５６０△Ｅｆｌ十２３．３８２Ｏ（Ｋｃｍ－１）ｒ＝０．９８８１Ｉｎφ＝－０．８４０７Ｉｎ△Ｐ—４．００４４ｒ＝０．９０７９     

Direct SCF direct static-exchange calculations of electronic spectra

Applications of the direct SCF direct static-exchange method are reviewed for three different types of systems (free molecules, polymers, and surface adsorbates) and for six types of spectroscopy (X-ray absorption-, -emission-, and -shake-up spectroscopy, ultraviolet photoelectron emission, X-ray Raman and circular dichroism spectroscopy. Received: 28 December 1996 / Accepted: 8 April 1997     

Excited states and multi-exciton complexes in single CdTe quantum dots

We present an optical study of excited states in single CdTe quantum dot (QDs). Using micro-photoluminescence excitation spectroscopy, absorption up to two confined excited levels have been observed in some dots. Power-dependent micro-photoluminescence is then used to study the occupation of excited states. The emission pattern is characteristic of the increase of the exciton number in the QD (shell-filling). A clear identification of the different multi-exciton complexes has been obtained in a highly symmetric dot. The evolution of the different multi-exciton intensities can then be reproduced by solving the rate equations for multi-exciton state occupancy and the fit by this simple model provides an estimate of the radiative lifetime of the different multi-exciton complexes.     

飞秒相干光场激发固体样品的线性与上转换荧光光谱研究

用可变延时的双光束激光激发固态样品,同时测量样品的线性荧光和上转换荧光强度.理论上用Bloch方程描述了激发态吸收上转换过程,通过数量方法解Bloch方程,得到了与激发态吸收过程相关的各能级粒子数布居随时间的变化关系,计算出荧光强度,得到有一定延时的两束光的相干光谱,相干光谱的计算结果和实验结果一致。