单分子检测技术的发展现状及展望

主要介绍了近年来单分子光谱检测技术从低温到高温、从非溶液介质到水溶液、从固体到活细胞、从有机燃料到纳米颗粒等方面的发展情况,并简单介绍了几种单分子检测的方法,最后对这一前沿领域进行了展望.     

多光子电离光电子的投影

近年来的一种新型光电子光谱仪被用来分析钠的多光子电离的光电子能量和空间分布.本文基于光电子成像光谱仪的基本原理,分析电子发射的动力学过程.以钠原子为例,利用共振多光子电离的方法研究并分析了电子初始角分布以及投影到探测器上的图像.结果表明,不同的初始条件(静电场能量和电子发射的初始动能之比),影响所获得的角分布以及探测图样.     

连通器辅助法快速调节分光计

针对光学实验中分光计调节困难的问题,采用连通器辅助调节法对分光计进行调节,实现快速调节,达到降低实验难度、节省实验时间的目的。     

拉曼光谱法鉴定水稻叶绿素缺乏突变体

植物叶色变异是自然界普遍的现象,叶色突变体已广泛应用于基础研究和生产实践。利用拉曼光谱测定了水稻叶色黄化突变体叶片的叶绿紊含量。研究结果显示：在拉曼光谱图中,叶绿紊的特征峰（1155,1527cm^-1）在突变体中强度较野生型有很大的下降,表明突变体中总的叶绿紊含量较低;紫外分光光度计的测定结果表明该突变体的叶绿紊含量比野生型降低,且叶绿紊b的含量极低,证实了拉曼光谱所反应的信息;拉曼光谱法可以用来快速鉴定植物活体的叶绿紊含量。本研究尝试利用拉受光谱测定活体生物的叶绿紊含量的可行性,为今后发展便携式、快速、准确、无损伤鉴定叶绿紊含量及其他生物质含量的方法和开发相关仪器提供研究思路。     

试析分光计载物台的角度补偿作用

本文首先明确了分光计载物台对三棱镜不垂直度的角度补偿作用.通过讨论,指出了三棱镜精度的主要标志是垂直度误差的提法不妥.提出了与实验密切相关的三棱镜质量的主要标志,是棱镜折射率n的均匀性和2个透光面的平面度;介绍了可调平面镜在分光计调整中的使用.     

三阶色散和自频移效应对孤子压缩的影响

通过数值求解高阶非线性Schrdinger方程,发现三阶色散和喇曼自频移效应对孤子脉冲的压缩会产生影响。正的三阶色散(TOD)和喇曼(RSS)效应使得孤子脉冲的压缩比减小;负的TOD和RSS效应使得孤子脉冲的压缩比增大。其中对于负的TOD和RSS效应,存在一个最佳的TOD参数值,选取这一最佳值,光脉冲压缩比达到最大。     

一种测量薄透镜焦距的新方法

本实验将分光计和读数显微镜结合使用,可以提高薄透镜焦距的测量精度。     

Tert-butyl amine borane complex: An unusual application of a reducing agent on model molecules of cellulose based materials

The need to preserve cultural heritage on paper requires the setting up of methods and treatments that can be applied to original documents. The cellulose main degradation processes are hydrolysis and oxidation. Only the first one has been widely investigated. The Istituto Centrale per la Patologia del Libro (ICPL) focused its attention on oxidation phenomena and studied a particular class of reducing agents, namely the borane-amine complexes. During the investigation it was found that the borane tert-butylamine complex, besides being the most promising reducing agent, was also able to react with carboxylic functions. In the present study ¹H and ¹³C NMR, Pulsed field gradient NMR spectroscopy as well as Raman spectroscopy were used as analytical tools to disclose the mechanism of the interaction between the borane tert-butylamine complex and the carboxylic functions. Given the complexity of the paper/environment interactions and the subsequent degradation phenomena, we worked on simplified models based on small carbohydrate molecules in order to reproduce the behavior of degraded paper after reductive restoration. Modified D-glucose and D-cellobiose were used in this first step in order to set up the analytical methods before approaching more complex systems such as microcrystalline cellulose and paper. Our results give the experimental evidence that borane tert-butylamine complex is also able to neutralize acidic functions. This finding has important perspectives in paper restoration.     

利用图表法分析分光计各半调节原理

利用图表分析法,给出了光学实验中分光计的各半调节方法,该方法有助于对分光调节原理的理解.     

Influence of double Rayleigh backscatter in CATV systems with Raman amplifiers

The double Rayleigh backscatter (DRB) effect in long distance CATV systems using fiber Raman amplifiers (FRAs) is investigated theoretically in the paper. As a comparison, performance of a system with erbium doped fiber amplifier (EDFA) is also evaluated. According to the simulation results, it is found that, in case of FRA, the increase of carrier-to-noise ratio (CNR) due to the DRB effect will not impair the performance more than that using EDFA.