中子衍射应力谱仪的垂直聚焦单色器的优化设计

本文应用蒙特卡罗模拟程序MCSTAS对中子衍射应力谱仪的垂直聚焦单色器利用单晶Ge（511）进行聚焦的情况进行了优化计算,得到垂直聚焦单色器的高度和单晶片间的倾角等参数的最佳值;同时对比分析了垂直聚焦单色器与平板单色器两种情况下样品处的中子注量率。最后讨论了单色器起飞角对谱仪分辨率产生的影响。     

Preparation of TEM foils from Nb-10 a/o Si.

Ductile phase toughened composites contain phases with significantly different physical properties. Consequently, these phases thin at different rates depending on the sample preparation procedure. A new TEM foil preparation method for the ductile phase toughened Nb-10 a/o Si material has been developed. The method involves chemical thinning in a 70% nitric acid/30% hydrofluoric acid solution followed by electropolishing in a 12.5% sulfuric acid/87.5% methanol electrolyte at -40 degrees C. This procedure for making TEM foils results in large thin areas with the minimum of artifacts. Mechanical grinding of a sample followed by either ion milling, dimpling, or electropolishing produced foils with large electron transparent areas, but with uncharacteristic features of the original Nb-10 a/o Si alloy microstructure. These artifacts were identified as dislocations, surface mottling, and antiphase domains.     

聚甲基丙烯酸甲酯材质硬X射线组合Kinoform透镜的制作

为提高硬X射线聚焦元件的聚焦性能,利用LIGA(Lithographie,Galvanoformung,Abformung)技术,制备了深度为60μm的聚甲基丙烯酸甲酯(PMMA)材质硬X射线组合Kinoform透镜(CKL),并获得了良好的面形。制备的CKL以宽度为几个微米的细窄线条为主要结构,包括曲面和直角面形,线条最窄宽度为2μm。为保证CKL良好的曲面及直角结构,样品制备分为三部分:过渡掩模板的制备,LIGA掩模板的制备,以及最终样品的硬X射线曝光制备。在LIGA掩模板制备过程中,采用制备有纳米柱阵列的硅衬底有效解决了光刻胶脱胶的问题。在最终样品制备过程中,选用分子量较高的PMMA片作衬底,提高了PMMA刚度,有效缓解了细窄线条的倒塌黏连问题,保证了CKL的良好面形。在北京同步辐射光源(BSRF)成像站测试了CKL透镜的性能,结果显示其对于8keV的X射线,聚焦焦斑的半高全宽(FWHM)为440nm。     

表面解吸常压化学电离质谱法快速测定冰毒

A method for rapid determination of narcotics by surface desorption atmospheric pressure chemical ionization mass spectrometry (DAPCI-MS) was established. The operation parameters including spray voltage, capillary temperature ect. on analysis performance were systematically investigated. Under the optimized experimental conditions, trace amounts of methamphetamine and caffeine in ice drug were detected rapidly without any sample preparation and pretreatment. Since DAPCI-MS allows rapid analyzing trace amounts of narcotics without sample pretreatment, it was also proposed to couple DAPCI source to a miniature mass spectrometer for fast in-situ analysis of narcotics．     

GELFISH – Graphical environment for labelling fluorescence in-situ hybridization images

Signal (dot) counting in fluorescence in-situ hybridization (FISH) images that relies on an automatic focusing method for obtaining clearly defined images is a time-consuming procedure prone to errors. Our recently developed system has dispensed with automatic focusing, and instead relies on a neural network classifying focused and unfocused signals into valid and artefact data, respectively, and thereby discriminating between in- and out-of-focus images. However, to train the classifier accurate labelling of the image signals is required. GELFISH is a Graphical Environment for Labelling FISH images that enables the rejection of unanalysable nuclei and labelling of FISH signals simply and rapidly. GELFISH is flexible and can be modified easily for additional FISH applications. Also, implemented using popular software, the environment can be employed on any computer by any user. Finally, GELFISH is proposed in controlling a classifier-based dot counting system.     

Digital data acquisition,display and analysis of signals from surfaces

A digital data acquisition and display system has been interfaced to an ultra high vacuum scanning electron microscope (UHV-SEM); the sample chamber contains detection systems for Auger and secondary electron spectroscopy and many in-situ surface preparation facilities. The acquisition system is being used for collection and display of this data in the form of spectra, line-scans and images. Subsequent analysis of stored data is done both on this system and on a similar off-line computer system. This paper describes the computer systems chosen and the detection and acquisition hardware developed. Program structures for on-line and off-line analysis are discussed. Examples of applications to surface science are given, including the collection and analysis of micro-Auger spectra, SEM picture analysis of crystals grown in-situ, and Auger and biased secondary electron imaging from sub-monolayer deposits.     

电感耦合等离子体质谱（ICP-MS）法测定微量元素时样品制备过程中的质量控制

Sample preparation is a key procedure for determiantion of trace elements in samples by inductively coupled plasma mass spectrometry. This paper gives some experiences on the quality control of sample preparation for determination of trace elements in samples by ICP-MS.     

空间飞行器表面原子氧密度传感技术综述与设想

对空间飞行器表面原子氧密度测量技术研究现状进行了探讨,并提出了一种新颖的测量方法设想,单个传感器采用YSZ(氧化钇稳定的氧化锆yttria-stabilized zirconia YSZ)作为敏感材料,通过测量YSZ阻抗变化的方法进行原子氧的测量.同时采用已知原子氧腐蚀速率的材料锇一起暴露测量,实现了对YSZ原子氧传感器的在线标定.该方案能解决空间飞行器表面原子氧密度的长期测量和传感器标定困难的问题.     

国标高效液相色谱法测定黄曲霉毒素的不确定度评定

依据GB/T18979-2003《食品中黄曲霉毒素的测定-免疫亲和层洗净化高效液相色谱法和荧光光度法》中的HPLC法,对花生中黄曲霉毒素测量的不确定度进行分析评定,对样品的制备、标准溶液的配制及检测等影响因素进行分析,确定各分量的分布类型,并进行分步计算和整体合成。     

微波消解法测定中成药中砷、汞元素的研究

采用微波消解样品 ,连续流动进样 -氢化物发生原子吸收分光光度法测定中成药中的砷 ,氢化物发生 -原子荧光光谱法测定中成药中的汞。对消解温度、消解试剂用量、消解程序设计、消解时间等消解条件进行研究 ;在测定汞时对微波消解样品后样品的处理方法进行比较 ;在优化实验条件下 ,砷的回收率为 10 0 8%～ 110 6 %之间 ,汞的回收率为 97 4 %～117 4 %之间。该法具有快速、简便、损失低、污染少、试剂利用率高等优点。