激光共焦显微拉曼光谱与应用

激光共焦显微拉曼光谱是近十年来发展迅速的一种分子光谱学方法。它是由激光器,全息滤光片衍射光栅,ＣＣＤ探测器,显微镜和计算机数据处理系统等主要部件构成的色散型拉曼光谱仪,它的特点是成象快速简便,分辨率高,适于微量分析,在化学化工,材料科学,生物,药物和法庭科学等领域均有广播的应用前景。     

拉曼光谱仪的两种共焦显微术的对比

介绍了拉曼光谱仪采用的共焦显微术的广泛应用；叙述了真共焦显微术的基本原理和优点，以及简单共焦（即“赝共焦”）显微术的主要缺点；列出了有关实验结果及数据对比。     

显微拉曼光谱技术检验射击残留物的研究

本文介绍了在室温环境下激光显微拉曼光谱分析方法对军用枪射击残留物检验研究的情况,得到了射击残留物的拉曼散射光谱图。该技术具有灵敏度高、分析速度快、检材量小、无需制样等特点,是检验射击残留物非常有效的方法。     

高温拉曼光谱仪

介绍了在原有ＪＯＢＩＮＹ′ＶＯＮＵ１０００型拉曼光谱仪上作的两种改造。一是配备了显微热台,实现了高温达１６２３Ｋ的共焦显微拉曼（Ｍｉｃｒｏ－Ｒａｍａｎ）;二是采用了光谱信号的时间分辨检测技术,实现了可达２０２３Ｋ温度下的宏观拉曼（Ｍａｃｒｏ－Ｒａｍａｎ）。拓展了拉曼光谱研究高温物质结构的应用。     

拉曼光谱成像技术新进展及其应用

拉曼光谱成像技术是拉曼光谱分析技术的新发展,借助于现代共焦显微拉曼光谱仪器以及新型信号探测装置,它把简单的单点分析方式拓展到对一定范围内样品进行综合分析,用图像的方式显示样品的化学成分空间分布、表面物理化学性质等更多信息。本文介绍拉曼光谱成像技术的基本原理和实验方法,并且特别介绍HORIBA Jobin Yvon公司的新型快速拉曼成像技术SWIFT和DuoScan,最后用实验实例说明这些技术的重要应用。     

激光共焦显微光束的偏转扫描

为了提高激光共聚焦系统的扫描速度,本文提出一种逐场扫描的场同步扫描方法。构建了激光共焦显微系统,将美国THORLABS公司的GVS002型二维检流计振镜应用于该系统,根据光学系统参数以及扫描范围要求计算振镜的整场扫描波形。借助NI公司的PCIe6353多功能数据采集卡,输出行同步的扫描波形,同时,对共焦显微系统共焦位置上针孔处的光强信号进行采集,先后扫描一幅256×256和512×512的图像,记录扫描图像和成像时间;然后,在相同的硬件结构下,以场同步的方式输出扫描波形,记录扫描图像和成像时间。实验结果表明:场同步方式扫描256×256图像的速度可提高10倍,扫描512×512图像的速度可提高5倍,且满足共焦显微成像的清晰、抗干扰能力强等要求。与行同步扫描方法相比,场同步扫描方法可以消除行与行之间转换的停留时间,在不改变硬件的情况下大幅提高扫描速度。     

光谱共焦位移传感器镜头设计研究

光谱共焦位移传感器是一种高精度、非接触式位移传感器。本文讨论了光谱共焦法用于位移测量的基本原理,用Zemax光学设计软件完成了一个镜头组的设计,并给出了光谱共焦位移传感器镜头组的设计方法以及像差分析。该镜头组采用密接透镜结构,工作波段为486.13nm-656.27nm,测量范围约为91μm,轴向响应FWHM优于5μm。通过线性回归分析得出波长与位移间判定系数为0.99523,在测量范围内,位移与波长间的线性关系较好。     

电化学反应过程中黄铜表面的原位显微拉曼光谱分析

利用显微共焦拉曼光谱仪在线分析了在以十二烷基硫酸钠水溶液为电解液、石墨为辅助电极时电化学反应过程中黄铜表面化学成分的变化，进而分析了外加电压引起摩擦因数变化的机理。结果表明：外加电压对摩擦因数的控制主要通过对表面有机离子吸附膜的影响来实现；黄铜表面存在有机离子吸附或反应而形成的边界润滑膜时摩擦因数较低；黄铜表面不存在有机离子润滑膜而存在较多的氢氧根离子时摩擦因数较高；溶液的搅拌对电控摩擦的恢复有较重要的作用。     

激光显微拉曼光谱仪的设计与性能参数测定

激光显微拉曼光谱仪是一种具有较高的空间分辨率,适用于固体定性分析和液体定量分析的微区无损检测系统,综合了光学、机械、电子和计算机等技术。可以快速鉴别各种材料,并且具有成像分辨率高、分析速度快、使用简单等特点。针对这些特点,完成了激光显微拉曼光谱仪的设计和参数测量。首先阐述了激光显微拉曼光谱仪的分析基础,然后介绍了激光显微拉曼光谱仪设计,最后详细说明了对光谱仪的性能参数测定。调试完成的激光显微拉曼光谱仪的重复性和线性度参数均已达到预期的设计,满足固体微区检测和液体定量检测的需要。     

光谱共焦显微镜的线性色散物镜设计

由于色散物镜轴向色散与波长间的非线性会导致仪器整体性能下降,本文研究了光学系统轴向色散与透镜组之间的关系,推导了轴向色散的传递公式.为得到较大的线性轴向色散,根据轴向色散的传递公式提出了一种正负透镜组均采用线性色散光焦度组合且正负透镜组分离的镜头结构.光学优化设计表明,具有正负透镜分离结构的色散物镜可以得到低的球差和大的轴向色散,而且具有较大的工作距离.设计的色散物镜在430～710 nm得到了1 mm的轴向色散,轴向色散与波长之间的相对非线性度为4.6％,灵敏度的波动量小于整体的1/3,优于之前的研究.采用所设计的色散物镜,光谱共焦显微镜能够得到优于0.3 μm的轴向分辨率和优于5 μm的横向分辨率,满足精密测量的需求.     

基于激光共焦扫描显微镜方法的磨损表面三维数字化描述

表面形貌的精确描述在许多领域诸如材料、生物医学、摩擦学和机器状态监测等领域变得越来越重要。开发了一种基于激光共焦显微镜和图像处理技术的研究磨损表面及表面参数的新方法。首先用B io-rad Rad iance 2000激光共焦显微镜方法获得精确的三维表面形貌,然后用计算机辅助图像分析技术自动计算出表面特征参数。应用示例表明本文所研究的方法是可靠的,能对工程表面的表面粗糙度特征进行精确描述。     

激光扫描共聚焦显微镜技术的发展及应用

激光扫描共聚焦显微术是先进的分子和细胞生物学研究技术。它在荧光显微镜成像的基础上加装激光扫描装置,结合数据化图像处理技术,采集组织和细胞内荧光标记图像。在亚细胞水平观察钙等离子水平的变化,并结合电生理等技术观察细胞生理活动与细胞形态及运动变化的相互关系。由于它的应用范围较广泛,已成为形态学、分子细胞生物学、神经科学和药理学等研究领域中很重要的研究技术。     

Confocal imaging with bilateral scanning and array detectors

A novel arrangement for confocal microscopy is presented, in which the key elements are the use of an array detector such as a CCD for confocal image collection and the use of one double-sided scanning mirror element for bilaterally scanning the object and collecting the data on the CCD. The resulting arrangement is shown to be capable of confocal imaging with high photon efficiency under adjustable conditions of confocality and varying image acquisition rates, i.e. from slow speed up to real-time imaging. Either laser or conventional light sources may be utilized. In addition to CCD registration, direct observation by eye of the confocal image in fluorescence is also possible.     

ZnO纳米线的光致发光性及拉曼散射性能

利用物理热蒸发法通过控制载气流量和氧气流量制备出具有倒V字形尖端的ZnO纳米线,利用荧光光谱仪、拉曼光谱仪对ZnO纳米线的光致发光性能和拉曼散射性能进行了测试.结果表明:与其它形状的ZnO纳米线的光致发光性能不同,该ZnO纳米线在423～458 nm区域有二个宽频带强蓝光发射,在527 nm处出现一个非常弱的绿光发射,没有发现紫外光发射;相对于ZnO纳米粉,ZnO纳米线的拉曼光谱峰发生约3 cm-1红移,主要来源于光子限制效应.     

Confocal laser scanning microscopy to study formation and properties of polyelectrolyte nanocapsules derived from CdCO3 templates

Three-dimensional confocal laser scanning microscopy (CLSM) was used as an essential investigation method to obtain information about the formation and morphological characteristics of nanocapsules. Nanocapsules are built by layer-by-layer deposition of alternatively charged polyelectrolytes on templates forming nanostructured hollow shells. CLSM is unique in allowing for monitoring of the core dissolution process in real time and for studying nanocapsule functioning in hydrated conditions within a three-dimensional and temporal framework. Since we are also interested in the identification of other possible templates, we briefly report on the use of yeast cells as biocolloidal cores monitored by means of two-photon microscopy. Here we focus our attention on the use of CdCO(3) crystals as template candidates for the preparation of stable capsules. Both cubic and spherical CdCO(3) cores have been produced. Cubic cores exhibit higher monodispersity and smaller size compared to spherical ones. Capsules templated on these cores have a higher surface-to-volume ratio that is valuable for applications related to drug delivery, functional properties of the shells and adsorption of proteins, and other biologically relevant molecules. Microsc. Res. Tech. 59:536-541, 2002.     

Effects of ethanol,formaldehyde, and gentle heat fixation in confocal resonance Raman microscopy of purple nonsulfur bacteria

Resonance Raman microscopy is well suited to examine living bacterial samples without further preparation. Therefore, comparatively little thought has been given to its compatibility with common fixation methods. However, fixation of cell samples is a very important tool in the microbiological sciences, allowing the preservation of samples in a specific condition for further examination, future measurements, transport, or later reference. We examined the effects of three common fixatives—ethanol, formaldehyde solution, and gentle heat—on the resonant Raman spectrum of three generic bacteria species, Rhodobacter sphaeroides DSM 158^T, Rhodopseudomonas palustris DSM 123^T, and Rhodospirillum rubrum DSM 467^T, holding carotenoid‐ and heme‐chromophores in confocal Raman microscopy. In addition, we analyzed the effect of poly‐L ‐lysine coating of microscope slides, widely used for mounting biological and medical samples, on subsequent confocal Raman measurements of native and fixed samples. The results indicate that ethanol is preferable to formaldehyde as fixative if applied for less than 24 h, whereas heat fixation has a strong, detrimental effect on the resonant Raman spectrum of bacteria. Formaldehyde fixation excels at fixation times above 24 h, but causes an overall reduction in signal intensity. Poly‐L ‐lysine coating has no discernable effect on the Raman spectra of samples fixed with ethanol or heat, but it further decreases the signal intensity, especially at higher wavenumbers, in the spectra of samples fixed with formaldehyde. Microsc. Res. Tech. 74:177–183, 2011. © 2010 Wiley‐Liss, Inc.     

用激光拉曼频移测定乙醇水溶液的浓度

为了进一步探索用激光拉曼光谱测定乙醇水溶液中乙醇浓度的方法,研究了室温下C-H伸缩振动频移与溶液浓度的关系.室温下,在Renishaw 1000型激光拉曼光谱仪上测得了不同浓度乙醇水溶液在500～4 000 cm-1的拉曼光谱,发现溶液位于2 800～3 050 cm1的3个C-H伸缩振动特征峰的峰值位置相对纯乙醇对应...     

Using confocal Raman microscopy to real‐time monitor poplar cell wall swelling and dissolution during ionic liquid pretreatment

The ionic liquids (ILs) are recognized as the potential solvents for the pretreatment of lignocellulosic materials before biomass conversion. However, little knowledge of how the cell wall of biomass responds to the IL locally and dynamically during the pretreatment is available. In the current work, the process of IL pretreatment of poplar using 1‐ethyl‐3‐methylimidazolium acetate ([C₂mim][OAc]) was real‐time monitored on a cellular level by employing confocal Raman microscopy. The results showed that the biomass dissolution during the IL pretreatment can be clearly divided into two stages: (1) slow penetration of IL, and (2) rapid dissolution of lignin and carbohydrates. In this case, the onset of the dissolution of these compositions occurred only after the cell wall of biomass swelled to a certain extent. Because the first stage was a slow process which determined the process reaction rate, it can be deduced that enhancing the penetration capacity of IL was crucial for improving the pretreatment efficiency. Based on the obtained results, a model was proposed to better understand how the plant cell wall responds to the IL before, during, and after pretreatment. Microsc. Res. Tech. 77:609–618, 2014. © 2014 Wiley Periodicals, Inc.