隐失波荧光显微镜及其在植物细胞生物学中的应用

隐失波荧光显微术（evanescent wave fluorescence microscopy,EWFM）是一种对细胞膜附近的生物学过程进行选择性观测的光学显微成像技术,该技术是基于全内反射原理,即当光在生物样品表面产生全内反射时,虽然在样品表面未被光直接照亮,但它仍会产生一种隐失波,这种隐失波却有足够能量将样品表面100～200 nm范围内的荧光基团激发。由于这一特性使得隐失波荧光显微镜能对靠近细胞膜的生物学过程,如胞吞胞吐、单个分子与细胞膜的结合和解离,以及膜上受体的动态变化过程等进行更好的观测。本文简略地介绍了隐失波荧光显微术的原理,同时对其在细胞生物学,特别是在植物细胞生物学中的应用作了初步总结。随着隐失波荧光显微镜的商业化及其观测技术的不断改进,它将在生命科学领域的研究中发挥越来越大的作用。     

荧光共振能量转移技术在生命科学中的应用及研究进展

荧光共振能量转移(FRET)是指两个荧光基团间能量通过偶极-偶极耦合作用以非辐射方式从供体传递给受体的现象,可被用于测定分子间的距离.FRET荧光探针主要有荧光蛋白、有机荧光染料、镧系染料和量子点,近年来有许多新的应用;测试方法上与时间分辨、单分子检测、荧光寿命和荧光相关光谱等技术联用取得了更好的成效.     

泵浦/探测增益光谱学

近些年来,采用两束不同频率的激光作为泵浦/探测技术来研究分子的激发态光谱,愈来愈为人们广泛应用。而对于光谱信号的检测,通常有两种不同的方法。一种是检测分子被激发后所发射的荧光。但是,检测荧光存在一个缺点是要想提高待测信号的光谱分辨率或时间分辨率或空间分辨率,都将使检测的灵敏度降低。另外,对于液态或溶液的有机分     

矿化生活垃圾淋滤液对地下水污染的模拟与荧光光谱识别

通过实验室模拟矿化生活垃圾淋滤液对地下水的污染,分析受污染地下水的三维荧光光谱特征,并利用FRI法(fluorescence regional integration)研究相应的三维荧光光谱组分特征信息,为建立基于光学表征技术的地下水污染监测应用提供理论基础.研究结果如下:淋滤液的三维荧光光谱图中的荧光中心位于Ex/E...     

基于光谱分离的定量荧光共振能量转移检测

由于天然克服光谱串扰的能力以及高灵敏和无损伤的特性,基于光谱分离的荧光共振能量转移(FRET)定量检测(spFRET)方法被公认为是最有应用潜力的活细胞定量FRET检测技术。首先简要介绍FRET定量检测方法以及国内外的相关研究进展;其次重点介绍基于发射光谱线性分离(Em-unmixing)和基于激发发射光谱线性分离(ExEm-unmixing)的两种定量FRET检测技术的原理、发展进程,并比较了这两种检测技术的稳健性;最后对这两种spFRET技术在活细胞FRET应用中的潜在优势进行展望。     

基于太赫兹时域光谱技术的农药残留检测方法

太赫兹时域光谱(THz-TDS)技术是近年来涌现出来的崭新的光谱测量新技术.本研究提出了一种基于THz-TDS技术农药残留检测方法,并以灭多威和乙氧氟草醚两种农药作为实验介质证明此方法的可行性.应用太赫兹时域光谱系统测得了这两种农药的时域光谱信号,利用基于菲涅尔公式的数据处理模型得到了它们在THz波段的折射率谱和吸收系数谱.从实验结果可以看出两种农药在0.2~2.0THz范围内存在明显的特征吸收峰,且差别很大.经分析认为这些吸收峰是由分子的集体振动模式以及分子间相互作用引起,它们是农药分子的指纹吸收光谱,可以应用于分子识别中.本研究证明了THz-TDS技术应用于农药残留检测的可行性,表明其在农药残留检测中具有潜在的应用价值.     

光谱及光谱成像技术在生物医学领域应用简介

光谱技术和光谱成像技术因其可以获取观测目标的化学组分信息,在生物医学领域具有极广阔的应用前景。介绍了光谱及光谱成像技术在生物医学领域七种应用的最新进展。其中,荧光多标记共定位、染色体核型分析及眼底病变检测技术已成熟,并已进入临床应用;光谱成像癌变检测、生物芯片检测、无损血糖检测及拉曼癌变检测四类应用虽然临床意义重大,但因检测精度较低或普适性较差等原因,处于发展初期阶段,仍需开展进一步研究。     

植物中活性氧信号转导及其检测方法研究进展

活性氧(ROS)作为一种重要信号分子在植物体生命活动的多方面发挥着关键作用。为对活细胞内的ROS分子进行研究分析,人们发展出了多种检测手段。其中,荧光探针作为一种高度灵敏、直观的标记技术,在植物ROS研究中得到广泛应用。近年来,通过蛋白质工程和基因工程技术,研究者们基于绿色荧光蛋白创造出一批新型的特异性荧光探针,为进一步探索植物体内ROS信号途径提供更有力的工具。本文概述了植物细胞中ROS信号转导通路,并总结针对不同ROS组分的多种研究方法,尤其对利用荧光探针标记技术检测胞内ROS的研究进展进行详细介绍。     

LIBS用于气溶胶分析的研究与应用进展

激光诱导击穿光谱（Laser-induced breakdown spectroscopy, LIBS）技术作为一种多元素实时检测技术,已被众多研究者用于气溶胶成分的原位在线分析。对近年来LIBS技术应用于大气气溶胶的研究概况和进展进行了简要综述: 简述了LIBS技术的原理与特点,分析了LIBS用于气溶胶检测的影响因素,总结了LIBS用于气溶胶分析的研究概况,并介绍了LIBS在大气环境及工业过程中的应用实例。     

以拉曼散射展示超声气流

用瑞利散射和激光感生荧光之类的技术可实现通过喷嘴气流的成像。荷兰奈梅亨大学应用物理系M.Sijtsema等人发展了另一种方法 ,它采用拉曼光谱术。整个气流密度可通过瑞利散射成像 ,但找出特定分子密度分布要求使用激光感生荧光或拉曼散射之类的技术 ,这两种技术都提供与特殊分子有关的特定光波长。虽然拉曼技术的散射效率远低于激光感生荧光或瑞利散射 ,但它有另外的优点。拉曼信号是分子特有的 ,可用光谱方法从强反射中分离或从其它类型散射中分离。其信号强度与分子密度成正比。与此相反 ,激光感生荧光的信号强度受分子中温度和压力差 (…     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.     

New insert layer structure OLEDs

An insert layer structure organic electroluminescent device（OLED） based on a new luminescent material （Zn（salen）） is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn（salen）/Liq/LiF/A1/CuPc/NPD/Zn（salen）/Liq/LiF/A1. Effective insert electrode layers comprising LiF（1nm）/Al（5 nm） are used as a single semitransparent mirror, and bilayer cathode LiF（1 nm）/A1（100 nm） is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.