用超声化学法制备有机包覆纳米银

纳米级银粉，以其纳米尺寸所赋予的独特性能，可广泛应用于催化剂材料、电池电极材料、低温材料和导电浆料，探索纳米银粉的制备方法具有重要的意义。2004年，通过超声化学法，在乙二醇介质中、以硝酸银为原料制备出了有机包覆的纳米银。产物用X射线光电子能谱仪（XPS）、透射电子显微镜（TEM）和红外光谱等进行了检测。     

光学傅氏变换离焦近似及对解卷积的应用

本文研究了光学傅氏变换的离焦近似问题,导出了使傅氏变换关系近似成立在光学上所需要满足的离焦条件,并以此为基础,提出用离焦谱平面方法对电子显微照相图象进行解卷积处理,使得光学解卷过程大大简化。实验得到了满意的结果。 关键词：     

Thermal Properties of Materials Characterized by Scanning Electron-Acoustic Microscopy

A modified technique of scanning electron-acoustic microscopy is employed to determine thermal diffusivity of materials. Using the dependence of the electron-acoustic signal on modulation frequency of the electron beam, the thermal diffusivity of materials is characterized based on a simplified thermoelastic theory. The thermal diffusivities of several metals characterized by the modified scanning electron-acoustic microscopy are in good agreement with the referential values of the corresponding materials, which proves that the scanning electronacoustic microscopy can be used to characterize the thermal diffusivity of materials effectively. In addition, for micro-inhomogeneous materials, such as biological tissues, the macro-effective （average） thermal diffusivities are characterized by the technique.     

H等离子体处理对Si中He注入空腔引起的效应

室温下分别采用40,160和1550 keV的He离子注入单晶Si样品到相同的剂量5×10¹⁶cm^-2,部分经He注入过的样品然后再分别接受高密度H等离子体处理.利用透射电子显微镜分析比较了随后800°C高温退火引起的空腔形成.结果表明,附加的H等离子体处理对空腔生长所产生的效应明显地依赖于He离子的能量.对于40 keV He离子注入,空腔的形成和热生长似乎不受H等离子体处理的影响,而对于160 keV He离子注入,附加的等离子体处理则促进了空腔的生长并伴随着空腔分布区域的变窄.对于1550keV He离子注入,H等离子体处理对空腔产生的效应介于40和160 keV注入情况之间.结合H等离子体处理在Si中所引起的缺陷的产生及其热演变过程对实验结果进行了讨论.     

分析型反射电子显微镜和表面科学：实验技术和发展

本文综述了反射电子显微术(REM)和反射电子能量损失谱(REELS)在表面科学中的应用。较详细地给出了用这些方法研究表面原子结构、化学成份和电子态的基本实验和理论,指出了发展这一学科对表面研究的重要性。     

膜催化研究IV: 钯-氧化铝/陶瓷复合膜

本文在无机氧化铝膜的基础上掺入钯, 用sol-gel法制得钯-氧化铝/陶瓷复合膜, 将该膜用于乙醇脱氢制乙醛反应, 分别考察了反应温度、乙醇进样量以及内管惰性气体吹扫气流对乙醛产率的影响, 并在相同条件下比较了常规反应器及单纯氧化铝膜反应器的结果。实验数据表明, 氧化铝膜中掺入钯后可显著提高乙醛产率。本文测定了该复合膜的H2/Ar分离系数、孔径分布, 并利用电子显微镜、X射线衍射等手段对其进行了表征。     

等离子喷涂陶瓷涂层的声学显微象

木文应用了声学显微镜分析了等离子喷涂陶瓷涂层(Metco 136F,Metco 80NS,国产Al_2O_3)于磨削加工和摩擦试验后的表面及内部结构特征。结果表明,声学显微镜能无破坏地观察材料内部的紧密度、空穴、变形、缺陷、裂纹等,反映了材料的力学象。这是传统的光学显微镜、扫描电子显微镜无法相比的。声学显微镜与光学显微镜、扫描电子显微镜配合,必将使材料科学的研究进入一个新的时代。     

微波等离子体化学气相沉积合成掺氮金刚石薄膜的缺陷和结构特征及其生长行为

Diamond film was deposited in CH₄ and H₂ gas mixture with a small amount of N₂ by microwave plasma assisted chemical vapor deposition (MPCVD). Scanning electron microscopy, Raman spectroscopy and transmission electron microscopy were applied to characterize the film. The results showed that the growth of grains are different the central region and the edge. In the central region, diamond grains nucleated with a density as high as 4.8×10⁸ cm^-2 and were preferential in 〈001〉 orientation. The inner grains formed an area without stacking faults,which was surrounded by a rim with a high density of stacking faults. A growth model was suggested to interpret the morphological feature and the behavior of preferential growth. At the edge, the grains were identified to be 6H polytypes of diamond and a new twin relationship of grains was found. Besides, the effect of the N dopant on the growth behavior of the diamond film deposited by MPCVD was discussed in connection with the growth rate of the film. 关键词： 金刚石 结构表征 透射电子显微镜 多型金刚石