EVO MA 15钨灯丝扫描电子显微镜的日常维护

钨灯丝扫描电子显微镜具有造价和运行成本低、样品适用性广的特点,在各研究机构的利用率很高,日常维护保养是保障其性能的必要手段.除了常规的扫描电子显微镜维护以外,因钨灯丝扫描电子显微镜结构特点,又有一些异于其它类型扫描电子显微镜的维护要点.以蔡司的EVO MA 15型钨灯丝扫描电子显微镜为例,从电子光学系统、真空系统、成像系统三个方面,阐述了钨灯丝扫描电子显微镜日常维护保养的具体办法,以供同行参考.     

扫描电化学显微镜在生物医学领域的应用研究进展

研究病变细胞和组织的异常表现可为理解重大疾病发生发展的病理机理和新型药物筛选提供重要参考.扫描电化学显微镜(Scanning electrochemical microscopy,SECM)是一种基于电化学原理的扫描探针显微镜,通过记录探针在样品表面扫描时的电流或电位等信息,对活细胞的形态和多种化学信息进行原位、实时、精准表征.近10年来,SECM在重大疾病相关的细胞、细胞球和微组织层次的应用研究得到快速发展.本文从与疾病相关的SECM研究角度入手,分别从单细胞、细胞球和微组织层次小结SECM近10年来在生物医学领域的应用研究进展.首先介绍SECM的仪器组成、探针种类和工作模式,其次分别介绍SECM在神经细胞、心肌细胞和肿瘤细胞的应用进展,之后介绍SECM近期在细胞球和微组织的最新应用,最后提出并展望SECM技术在生物医学领域进一步应用所面临的挑战和发展方向.     

复合型扫描微pH电极及其在局部腐蚀中的应用

研制了一种新型的微米级复合型扫描pH探针.该探针具有体积小、响应速度快、稳定性好和制作方便等优点，能很好地满足微区pH快速测定的要求.应用复合型扫描微pH电极技术研究了Al/Cu合金在0.01 mol•L－1 NaCl溶液中开路状态下局部腐蚀发生的早期过程.     

扫描电化学微探针的发展及其在局部腐蚀研究中的应用

简要概述当前国内外具有空间分辨能力的扫描微探针技术及其在腐蚀研究中的应用,包括扫描微电极技术(SMET)、扫描电化学显微镜(SECM)、原子力显微镜(AFM)、扫描Kelvin探针技术(SKP)等,其中SMET、SECM、SKP及局部交流阻抗技术可直接测定腐蚀电极表面或界面电化学不均一性的分布图像,而原子力显微镜技术则是通过分子间作用力从纳米尺寸测量腐蚀过程表面形貌的变化.文中侧重介绍作者近年先后建立的具有微米空间分辨度的电化学微探针技术,并利用各种扫描探针技术研究金属/溶液界面电化学不均一性及其局部腐蚀过程.研究表明,空间分辨电化学方法的发展及应用,加深了人们对金属表面和金属/溶液界面电化学不均一性,特别是金属局部腐蚀发生、发展及过程机理的认识.     

基于LSCM的线扫描方向识别方法的建立与应用

激光扫描共聚焦显微镜(LSCM)具有高分辨率和高光学切片的成像能力,是生命科学研究不可或缺的工具。通常采用的XY或者XYZ扫描方式成像速度慢,限制了生物研究中快速现象的追踪。本文介绍了实时快速成像的XT线扫描模式,并建立线扫描方向的识别方法。制作荧光小球样本,经过荧光小球划出不同方向的线段,使线段的一端接近荧光小球的中心而另一端远离,对线段进行XT线扫描,根据荧光信号与两端距离的远近判断扫描方向。阐述了XT线扫描在Zeiss、Nikon和Olympus共聚焦显微镜中的具体操作方法,并比较了其线扫描方向的差异。本研究建立了一套确定线扫描方向的实用方法,该方法简便易操作,具有普遍适用性,可为显微成像从业者和研究者提供借鉴。     

扫描透射电子显微镜技术及其在中药研究中的应用

扫描透射电子显微镜(STEM)兼具透射电子显微镜(TEM)和扫描电子显微镜(SEM)的优势,具有高分辨成像、强原子衬度敏感以及图像易懂、直观等优点,已成为材料微结构和微区分析的必要性工具. 中药研究有着悠久历史,显微技术一直是研究药材微特征和作用机制的重要手段之一,具有其他手段不可替代的作用. 综述了STEM的原理、方法、技术特点,以及其在中药显微结构和纳米颗粒等方面的应用,以期为进一步扩展中药微特征领域的研究作参考.     

扫描探针显微术在巯醇自组装单分子膜纳米刻蚀中的应用

介绍了近十年来扫描探针显微术(SPM)在巯醇自组装单分子膜纳米刻蚀中的应用. 依据扫描探针的工作原理, 依次讨论了扫描隧道显微镜、原子力显微镜和导电原子力显微镜的工作特点和适用范围. 同时也讨论了自组装单分子膜纳米刻蚀术在生物分子传感器、超高密度信息存储等领域的应用前景.     

(苄基三乙基铵)双(1,3-二硫杂环戊烯-2-硫酮-4,5-二硫基)-金的三阶非线性光学性质

合成了一种新的配位化合物(苄基三乙基铵)双(1,3-二硫杂环戊烯-2-硫酮-4,5-二硫基)-金(BTEAADT). 利用旋涂技术制备了该材料与聚甲基丙烯酸甲酯(PMMA)掺杂的复合薄膜, 该材料在复合薄膜中的质量分数为1%. 采用Z扫描方法, 分别测试了该材料的乙腈溶液和该材料与PMMA复合薄膜在波长为1064 nm, 脉宽为20 ps条件下的三阶非线性光学特性. 同时还研究了复合薄膜的线性光学性质. Z扫描的结果表明, 复合薄膜和该材料的乙腈溶液都具有自散焦效应, 非线性折射率都是负值. 在实验条件下, 两者的非线性吸收效应都是可以忽略的. 经过计算得出溶液样品的非线性折射率为-1.459×10^-18 m²·W^-1, 复合薄膜样品的非线性折射率为-3.978×10^-15 m²·W^-1. 该材料在1064 nm处的非线性光学器件方面有潜在应用价值.     

卤化银微晶的含碘结构的测定

用超薄切片法及X-射线线扫描法研究了半个碘溴化银微晶中碘的成层分布,结果与预想的碘的分布相一致。横扫过薄样品的X-射线线扫描提供了一个比较准确的测定含有不同碘量成层结构的技术。这有助于我们改进碘溴化银乳剂的制备。文章还讨论了在该种工作条件下,X-射线源的空间分辨率和超薄切片的厚度。 利用这种方法,把一种商用多层彩色片做超薄切片,用X-射线线扫描法直接对超薄切片中卤化银微晶的断面扫描,得到了各个轧剂层中的卤化银微晶的含碘结构。     

SECM基本原理及其在金属腐蚀中的应用

扫描电化学显微镜（SECM）是一种具有较高空间分辨率的化学显微镜,在成像和动力学研究已经广泛应用. 本文简要介绍SECM基本原理,综述2009年以来SECM在腐蚀方面的应用,包括扫描成像和异相转移电子化学活性的研究,并简要介绍了作者课题组在SECM方面的研究工作,展望SECM在腐蚀研究的应用.     

Development of high-resolution optical scanning fluorescence microscopy

Instrumentation of a high-resolution optical scanning fluorescence microscope is presented. This instrument provides a fluorescent image of the structural surface of various kinds of thin membrane samples with high resolution on the molecular scale. For this instrument, a new excitation optical tip and a three-dimensional scanning unit have been designed. The optical tip consists of a sharpened optical fibre covered with evaporated aluminium in vacuo, on which the top has a pinhole. The optical tip is mounted in the centre of a crosslinked piezoelectric scanning head. On thez-axis, a piezoelectric positioner is equipped with a differential micrometer mechanism. All operations are controlled with a micro-computer system.The scanning area in this instrument is 4000*4000 nm₂ for measurements of biological specimens. Several optical scanning microscopic images as well as the STM image are presented.     

Assessment of dose measurement uncertainty using RisøScan

The dose measurement uncertainty of the dosimeter system RisøScan, office scanner and Risø B3 dosimeters has been assessed by comparison with spectrophotometer measurements of the same dosimeters. The reproducibility and the combined uncertainty were found to be approximately 2% and 4%, respectively, at one standard deviation. The subroutine in RisøScan for electron energy measurement is shown to give results that are equivalent to the measurements with a scanning spectrophotometer.     

Application of Scanning Tunneling Microscopy and Spectroscopy in the Studies of Colloidal Quantum Qots

Colloidal quantum dots display remarkable optical and electrical characteristics with the potential for extensive applications in contemporary nanotechnology. As an ideal instrument for examining surface topography and local density of states (LDOS) at an atomic scale, scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS) has become indispensable approaches to gain better understanding of their physical properties. This article presents a comprehensive review of the research advancements in measuring the electronic orbits and corresponding energy levels of colloidal quantum dots in various systems using STM and STS. The first three sections introduce the basic principles of colloidal quantum dots synthesis and the fundamental methodology of STM research on quantum dots. The fourth section explores the latest progress in the application of STM for colloidal quantum dot studies. Finally, a summary and prospective is presented.     

扫描电子显微镜与扫描隧道显微镜联用装置

在ＫＹＫＹ－１０００Ｂ型扫描电子显微镜上所开发的与其联用的袖珍型扫描隧道显微镜主要有四个部分：（１）减震阻尼装置,（２）隧道探针,（３）探针扫描与逼近装置,（４）电子控制与图象采集系统。它的分辨率约为１ｎｍ,并用它观察了半导体光栅与硅上金膜的细微结构。     

Calorimetric characterization of 2′,3′-dideoxyinosine water solution

A study of 2′,3′-dideoxyinosine (ddI) stability and its interaction with human serum albumin (HSA) was carried out by differential scanning microcalorimetry DSC. Scan rate dependent and irreversible endothermic thermal degradation of ddI was analyzed with use of kinetic approach. Observed process could be interpreted in terms of simple first-order one step kinetic model. Moreover it was shown that ddI bound weakly to the human serum albumin and stabilized this protein.     

Long-term lens organ culture system with a method for monitoring lens optical quality

The Scan Tox System is a method for monitoring lens optical quality (focus or lack of focus) in culture conditions, which mimic conditions inside the eye. The ocular lens is an ideal organ for long-term culture experiments because it has no direct blood supply and no connection to the nervous system. The Scan Tox System makes it possible to keep lenses for long-term studies of up to a few weeks. The use of cultured lenses, mainly bovine, replaces the need for testing the effects of potentially damaging agents on live animals. This optical monitoring apparatus uses a computer-operated scanning laser beam, a video-camera system and a video frame analyzer to record the focal length and transmittance of the cultured lens. The scanner is designed to measure the focal length at points across the diameter of the lens. The lens container permits the lens to be exposed to a vertical laser beam from below. The laser source projects its light onto a plain mirror, which is mounted at 45 degrees C on a carriage assembly. The mirror reflects the laser beam directly up through the test lens. The mirror carriage is connected to a positioning motor, which moves the laser beam across the lens. The camera sees the cross section of the beams and, by examining the image at each position of the mirror, Scan Tox software is able to measure the quality of the lens by calculating the back vertex distance for each beam position. The cultured lenses continue to maintain their original refractive function. When foreign substances are introduced to a cultured lens, the Scan Tox System measures the resulting optical response. This provides a very sensitive means to follow early damage to the eye lens. Because the lens is maintained in an intact state in solutions that are similar to those inside the eye, the lens retains its normal recuperative powers. So in addition to measuring early damage, this system allows measurement of recovery from damage.     

Fluorimetrische Routinebestimmung von Uran in Urinproben

With a modified RA 2 reflectance accessory for the Zeiss PMQ II/PMQ 3 spectrophotometer, uranium in urine was detected with higher sensitivity. A routine method is now available with a detection limit of <2 μg U/l urine for the determination of possible uranium incorporations, whose sensitivity meets the requirements of radiation protection. Compared with other extraction methods, the instrument outlay and the required working time are small. The total error of the method is below 5%.     

基于扫描探针显微镜（SPM）的高密度信息存储

随着信息技术的飞速发展,高密度信息存储的研究成为国际上备受关注的研究领域。扫描探针显微技术（SPM）通过改变材料的光、电、磁等局域特性可以实现纳米尺度的信息存储,成为提高信息存储密度的最有效手段之一。本文从信息存储材料和技术角度综述了基于SPM的高密度信息存储最近的研究进展,并讨论了其将来的研究和发展方向。