超声分子束中中性态和离子态吡咯烷的红外光谱

本文应用真空紫外光电离结合红外光解离以及飞行时间质谱技术获得超声分子束中吡咯烷单体在中性态和离子态的红外光谱. 研究发现，吡咯烷在中性态和离子态的CH伸缩振动均有不同程度的红移现象. 在中性态吡咯烷中，由于NH的电偶极矩较小，没有观察到NH伸缩振动峰. 而电离后的吡咯烷NH伸缩振动峰有很大的增强，并与其他实验相比出现红移现象. 通过理论计算发现中性态和离子态的CH伸缩振动的红移分别是由反超共轭和正超共轭现象引起的. 而NH峰的增强和红移则是由于N原子上的电子被电离所引起的. 通过计算分子的气态酸碱度发现，在离子态中，CH的酸性比NH的酸性略强.     

Self-assembly 2D plasmonic nanorice film for surface-enhanced Raman spectroscopy

As an ultrasensitive sensing technology, the application of surface enhanced Raman spectroscopy (SERS) is one interesting topic of nano-optics, which has huge application prospectives in plenty of research fields. In recent years, the bottleneck in SERS application could be the fabrication of SERS substrate with excellent enhancement. In this work, a two-dimensional (2D) Ag nanorice film is fabricated by self-assembly method as a SERS substrate. The collected SERS spectra of various molecules on this 2D plasmonic film demonstrate quantitative detection could be performed on this SERS substrate. The experiment data also demonstrate this 2D plasmonic film consisted of anisotropic nanostructures has no obvious SERS polarization dependence. The simulated electric field distribution points out the SERS enhancement comes from the surface plasmon coupling between nanorices. And the SERS signals is dominated by molecules adsorbed at different regions of nanorice surface at various wavelengths, which could be a good near IR SERS substrate for bioanalysis. Our work not only enlarges the surface plasmon properties of metal nanostructure, but also exhibits the good application prospect in SERS related fields.     

基于BB84协议的量子密钥分发安全门限研究

本文分析了实际量子密钥分发过程中,量子态可能受到的各种影响因素;建立了相应的信道模型;推得了非理想信道BB84协议判别窃听的安全门限公式.通过计算与仿真,证明该公式用于估计BB84协议的安全通信门限更加准确,判断量子密钥分发过程中是否存在窃听更为有效,同时具有提高通信安全性和密钥分发效率的优点. 关键词： 信道模型 BB84协议 窃听判别 安全门限