Thein-situ TEM observation of chemisorption facilitating dislocation emission, multiplication and motion

Summary The chemisorption of Hg atoms on the fracture surface of a loaded crack in Al single crystal can facilitate the dislocation emission, multiplication and motion.     

用于甲烷部分氧化制甲醛反应的超细MoO3／SiO2催化剂

对比研究两种不同载体ＭｏＯ３／ＳｉＯ２催化剂用于甲烷部分氧化反应，结果表明用醇盐法所制ＳｉＯ２做成的催化剂比用所买ＳｉＯ２做成的催化剂反应活性和选择性好；电镜（ＴＥＭ）结果表明前者是超细粒子催化剂，其平均粒径为１２．６５ｎｍ，粒度分布窄；ＢＥＴ及孔结构测定表明前者比表面积大，孔容及孔径小，孔径分布窄；ＴＰＲ结果表明前者ＭｏＯ３与ＳｉＯ２相互作用较弱。     

英语专业四级统考的考前强化训练

作为高校英语专业最大规模的统一测试，英语专业四级统考的综合性、权威性、科学性是毋庸置颖的，绝大多数院校都把英语专业四级统考作为衡量本校办学水平的一把重要尺子，因此，对其进行适当的强化训练以确保考生考出水平很有必要。但是，必须保证强化训练要在整体教学的框架下，将统考各项目和常规教学各门课程有机结合起来进行，不能影响整体教学、更不能打乱常规教学秩序。     

电子束诱导玻璃纳米须生长的原位电镜观察

在高能电子束辐照下,玻璃表面首先形成突起,在以后的辐照下以扩散限制凝聚的形式在无序态突起上生长出长度在十几到几百nm的树枝状玻璃纳米须,并沿玻璃法线方向生长.这一电子束诱导现象主要是由于照射部位的温升造成的,玻璃纳米须的长度和生长速度与辐照时间密切相关.辐照时间增加生长速度加快,在辐照23min左右时生长速度最快.整体形貌也随辐照时间而改变,玻璃纳米须从高低不平到高度整齐,从局部到整个面积均匀分布.     

FDTD 法求解对称与非对称 TEM cell 的截止频率

用ＦＤＴＤ法结合离散傅里叶变换在两维空间求解对称和非对称ＴＥＭｃｅｌ的截止频率。为模拟任意尺寸的内部导电板,采用了亚网格技术,计算了各种尺寸的对称和非对称ＴＥＭｃｅｌ的高阶模截止频率,讨论了ＴＥＭｃｅｌ截止频率与其尺寸的关系,对ＴＥＭｃｅｌ的设计具有指导意义。所得结果与已有文献的结果相吻合。     

Folding patterns of chromatin in chicken erythrocyte studied by using AFM and TEM

Four folding patterns (～15, ～30-40, ～60 and ～90-110 nm) of the higher_order structure of chromatin in chicken erythrocytes have been observed with an atomic force microscope (AFM) under near natural conditions. Results showed that the chromatin in the interphase nucleus of chicken erythrocyte was not in a disorganized form but represented a higher_order conformation. The thin sections of the chromatin in the nucleus of chicken erythrocyte were examined with a transmission electron microscope (TEM). Compared with TEM, AFM had the advantages that the samples did not need the preparation procedures such as fixing, sectioning and staining, and thus were closer to their native condition.     

L12有序结构Ni74.5Pd2Al23.5合金超点阵内禀层错的形成机制

用ＴＥＭ研究了Ｌ１２长程有序结构Ｎｉ７４．５Ｐｄ２Ａｌ２３．５合金室温变形后的位错结构．结果表明,加Ｐｄ韧化的Ｎｉ７４．５Ｐｄ２Ａｌ２３．５合金室温变形组织中存在着大量超点阵内禀层错．这些层错是从以反相畴态分解的ａ／２〈０１１〉位错通过进一步的分解和反应转变来的．层错的形成是合金变形过程中位错交互作用的二次产物,并不成为影响Ｎｉ７４．５Ｐｄ２Ａｌ２３．５合金变形和韧性的主要因素．     

瞬变电磁仪中几种干扰的消除方法

通过对瞬变电磁勘探法中常见的几种干扰因素的分析，提出了相应的解决方法，用程控天线法和随机双极性采样法抑制干扰具有良好的去噪效果。在实际中，只要根据具体情况选择适当方法，就能有效地抑制电磁噪声的影响。无论采用哪种方法，最后采用提取特征不变量的方法进行处理后，匀可以得到更好的效果。实验结果表明，测量曲线的质量较以前有很大提高。     

Small Diameter Few- Walled Carbon Nanotubes: An Alternative for Single Walled nanotubes in Bulk Applications

1Introduction Although Single walled carbon nanotubes have shown tremendous potential in many applications due to their unique electrical and mechanical properties, the lack of a large scale synthesis method at low cost is still the main limiting factor for the realization of the full potential of this unique materials. On the other hand, multiwalled carbon nanotubes are being made in tons per year quantity and found their application in conducting plastic and other bulk applications.     

深亚微米Flash NVMIC单元结构的电子显微分析

随着集成电路特征尺寸的不断缩小,器件结构越来越复杂,应用电子显微分析技术对IC的特定部位进行高空间分辨率的微结构分析,已成为IC新产品、新结构设计,新工艺开发和芯片生产质量保证的重要手段．结合深亚微米IC结构电子显微分析所涉及的FIB定位制样和TEM高分辨成像等关键技术的讨论,分析了一种新型的分立栅结构的深亚微米非挥发性闪烁存储器集成电路芯片(Flash NVM IC)的微结构特征,并从结构角度比较了其与堆叠栅结构Flash IC的性能.