一种精确测量液体折射率的方法

本文介绍了一种在迈克尔逊干涉仪光路加入一楔形样品池进行液体折射率测量的方法。     

磁处理水延缓CaSO4型结垢的机理研究

研究了外加磁场对Ｃａ２＋，ＳＯ２－４结成水垢的影响，通过计算磁场对离子水化半径及溶液粘滞系数的影响，给出了结垢速率与磁场强度、温度及溶液浓度的关系．计算结果表明，外加磁场的作用可以加强离子的水化程度，增大离子水化半径，降低离子的活度，从而减缓了水垢的形成和增长     

控制成核生长大尺寸C60，C70单晶

通过改进双温区双温度梯度方法，成功地控制成核密度，分别生长出线度可达6mm和5mm的大尺寸C₆₀，C₇₀单晶，并对其表面形貌和晶体结构进行了研究. 关键词：     

红外光谱在纤维质文物材料鉴别中的应用研究

纺织纤维和纸张纤维是常见纤维质文物材料, 是构成博物馆精美文物如服饰手稿书画的基本材料, 近年来寻求通过无损或微损方法对这一类材料的鉴别以及劣化状况评价备受文物鉴赏家和文物保护工作者的关注。借助傅里叶变换红外光谱, 研究博物馆常见纺织纤维材料棉、麻、桑蚕丝、柞蚕丝、羊毛的红外光谱特征和它们的分子结构组成异同, 研究传统纸纤维稻草、麦草、龙须草、龙旗松、桑皮红外光谱特征。结果表明: 衰减全反射傅里叶变换红外光谱无损分析技术可通过比较3 300～2 800 cm-1 CH, NH, OH振动区间光谱形状以及指纹区峰位以区别不同种类纺织品纤维;碳氧振动纸张纤维最明显光谱差异位置出现在与纤维素OH伸缩振动相关波数3 300 cm-1和与C—O—C相关波数1 332, 1 203, 1 050 cm-1。文章探索研究红外光谱技术结合主成分分析法在快速鉴别纤维材料中的应用。通过对全光谱数据多元散射校正(MSC)预处理后进行主成分分析, 可以把红外光谱十分相似的纺织纤维棉和亚麻、桑蚕丝和柞蚕丝明显分类;对光谱相似的纸纤维, 可采用选择不同光谱波数段进行主成分分析, 比较发现能够把五种纸纤维明显区分的光谱区间为3 800～2 800 cm-1。本研究为分子光谱无损分析技术应用于文物材料鉴别、科学评估纤维材料保存状况提供基础研究。     

单谐振腔束团长度监测器耦合结构设计与仿真

单谐振腔束团长度监测器利用谐振腔内的两个本征模式测量ps量级的电子束团长度,它的关键是如何将两个不同频率的模式互不干扰地耦合提取出来。为解决这个问题,基于低通和带通滤波器的理论,提出了同轴滤波耦合结构和膜片加载波导滤波结构,借助CST微波工作室对滤波器进行建模并仿真得到其S参数。为测试耦合器的应用效果,设计了一套带有该耦合结构的单谐振腔束团长度监测器探头,根据国家同步辐射实验室基于可调谐红外激光的能源化学研究大型实验装置FELiChEM的束流特点,在CST内对所设计的探头进行束流模拟仿真。仿真结果表明,该耦合器可以实现对特定模式的耦合,并有效降低其它模式的干扰,采用同轴滤波耦合结构和膜片加载波导滤波结构的谐振腔监测器可以实现对FELiChEM装置束团长度的高精度测量,测量误差小于2 %。     

基于LabVIEW平台的牛顿环虚拟仿真实验

利用LabVIEW平台设计了牛顿环的虚拟仿真实验平台,动态直观演示了利用牛顿环实验测量透镜曲率半径的过程,并分析了各参量对干涉现象的影响.提高了可视化效果和测量精度,降低了操作难度.并利用该程序模拟了测量介质溶液的折射率,对课堂实验进行了拓展.     

Theoretical study on the mechanism for the excited-state double proton transfer process of an asymmetric Schiff base ligand

Excited-state double proton transfer (ESDPT) in the 1-[(2-hydroxy-3-methoxy-benzylidene)-hydrazonomethyl]-naphthalen-2-ol (HYDRAVH₂) ligand was studied by the density functional theory and time-dependent density functional theory method. The analysis of frontier molecular orbitals, infrared spectra, and non-covalent interactions have cross-validated that the asymmetric structure has an influence on the proton transfer, which makes the proton transfer ability of the two hydrogen protons different. The potential energy surfaces in both S₀ and S₁ states were scanned with varying O-H bond lengths. The results of potential energy surface analysis adequately proved that the HYDRAVH₂ can undergo the ESDPT process in the S₁ state and the double proton transfer process is a stepwise proton transfer mechanism. Our work can pave the way towards the design and synthesis of new molecules.     

Synergistic influences of titanium,boron, and oxygen on large-size single-crystal diamond growth at high pressure and high temperature

The synergistic influences of boron, oxygen, and titanium on growing large single-crystal diamonds are studied using different concentrations of B₂O₃ in a solvent-carbon system under 5.5 GPa-5.7 GPa and 1300 ℃-1500 ℃. It is found that the boron atoms are difficult to enter into the crystal when boron and oxygen impurities are doped using B₂O₃ without the addition of Ti atoms. However, high boron content is achieved in the doped diamonds that were synthesized with the addition of Ti. Additionally, boron-oxygen complexes are found on the surface of the crystal, and oxygen-related impurities appear in the crystal interior when Ti atoms are added into the FeNi-C system. The results show that the introduction of Ti atoms into the synthesis cavity can effectively control the number of boron atoms and the number of oxygen atoms in the crystal. This has important scientific significance not only for understanding the synergistic influence of boron, oxygen, and titanium atoms on the growth of diamond in the earth, but also for preparing the high-concentration boron or oxygen containing semiconductor diamond technologies.     

Near-field multiple super-resolution imaging from Mikaelian lens to generalized Maxwell's fish-eye lens

Super-resolution imaging is vital for optical applications, such as high capacity information transmission, real-time bio-molecular imaging, and nanolithography. In recent years, technologies and methods of super-resolution imaging have attracted much attention. Different kinds of novel lenses, from the superlens to the super-oscillatory lens, have been designed and fabricated to break through the diffraction limit. However, the effect of the super-resolution imaging in these lenses is not satisfactory due to intrinsic loss, aberration, large sidebands, and so on. Moreover, these lenses also cannot realize multiple super-resolution imaging. In this research, we introduce the solid immersion mechanism to Mikaelian lens (ML) for multiple super-resolution imaging. The effect is robust and valid for broadband frequencies. Based on conformal transformation optics as a bridge linking the solid immersion ML and generalized Maxwell's fish-eye lens (GMFEL), we also discovered the effect of multiple super-resolution imaging in the solid immersion GMFEL.     

InGaAs/Si键合界面a-Si键合层厚度对InGaAs/Si雪崩光电二极管性能的影响

为从根本上阻断InGaAs/Si之间的失配晶格,获得低噪声的InGaAs/Si雪崩光电二极管,理论上在InGaAs/Si键合界面插入超薄a-Si键合层,彻底隔断键合界面异质晶格,同时保证InGaAs吸收层和Si倍增层超高的晶体质量和良好的电学传输.模拟了a-Si键合层厚度对InGaAs/Si雪崩光电二极管性能影响.由于...