Effect of strain on space charge layer in GaN nanowires investigated by in-situ off-axis electron holography

Effect of strain on space charge (SC) layer in nanowires (NWs) has been examined by in situ off-axis electron holography, where GaN NWs attach to an Au electrode inside a transmission electron microscope (TEM). Based on the phase image reconstructed from the complex hologram, the width of SC layer in a strained GaN NW is significantly reduced to about 60 nm, comparing to the 85 nm of the unstrained NW. About 29% reduction of the SC layer in the strained GaN NW resulted from significant decrease of electrons flowed from the GaN into Au. First principle calculations show that the strain reduced bandgap of GaN, narrowing the difference between GaN NW and Au electrode in Fermi level.     

功能语篇分析在TEM8阅读理解考试中的应用

借助Halliday系统功能语法中的语篇分析理论,从语境、及物性、主位和衔接的角度对往年TEM8（以下简称专八）阅读理解文章进行分析,旨在培养学生构建语篇意义、感悟语篇深层含义的能力,为专八考生的备考及应考提供参考。     

f.c.c孪晶衍射花样指标化的简化

在电镜衍射[1]中,衍射斑点的标定是常见的.当出现孪晶斑点[2]时,对于孪晶斑点的标定,许多研究者都感觉标定过程过于复杂.作者针对这一情况,推导出孪晶斑点标定的简化公式,这对于材料工作者的研究是很有意义的.     

Crystallographic similarity between the lath martensite and lower bainite in medium-carbon alloy steels

Progress in the crystallography of lath martensitic and lower bainitic transformations is briefly reviewed, followed by a presentation of the experimentally measured crystallographic characteristics of both lath martensite and lower bainite formed in mediumcarbon steels containing Si, Mn and Mo. It is found that the bainite plates relate to each other by a relative rotation of 54.7°or 60°about the normal to their common close-packed planes {110} b, which ensures a pseudo- {112}b twin relationship between two adjacent plates,and that all bainite variants formed in a single packet keep a unique G-T orientation relationship with the austenite matrix. These two types of OR of lower bainite are similar to that of the lath martensite, respectively. Furthermore, the measured habit planes of both the lower bainite and lath martensite are all {335} f type, which can verify the crystallographic similarity between the lath martensite and lower bainite.     

非傍轴部分相干光束传输的仿真

半导体激光器具有体积小、效率高等优点,广泛应用于激光通信、光信息处理等方面,但与其他激光器相比有较大的光束发散角,对这类激光束来说,傍轴近似失效。文章运用交叉谱密度函数针对半导体激光束建立了一个模型—非傍轴部分相干TEM11厄米-高斯(HG)光束,并对这类光束在自由空间中的传输特性进行了计算机仿真。发现f和fσ两参数对部分相干TEM11HG光束的非傍轴性起着至关重要的作用。另外,f和fσ的大小关系还决定了远场光强分布的形状。     

浅析圆柱形波导

尽管矩形波导是最常见的、被人们所广泛研究的波导,但其它形状的波导也是可能存在的.本文以共轴电缆为例,研究了圆柱形波导中的TEM简谐电磁波.     

西安文理学院TEM4考试成绩分析与综合英语课教学方法研究

目前旨在检验学生综合运用能力的英语专业四级测试越来越引起高校、学生乃至社会的高度重视,而培养学生综合运用能力的核心课程———综合英语课则更凸显其重要地位。通过西安文理学院近三年来的TEM4成绩分析,寻找综合英语内化教学与考试内容相结合的新方法。     

瞬变电磁法在勘探中的应用

应用瞬变电磁法探测确定了勘探区域内F1023和F23（古交断层）的位置,并根据电法低阻异常体划定了地下水富水区。     

甘肃金川南延铜镍硫化物矿床物化探综合找矿研究

为了缓解甘肃金川镍矿资源枯竭问题,实现资源的可持续发展,由高精度磁测法、大功率瞬变电磁法、地电化学法（包括地电化学提取、土壤离子电导率）和土壤吸咐相态汞测量法等组合综合找矿方法,在金川南延地区开展物化信息寻找隐伏镍矿预测研究。结果表明,高精度磁测法对金川南延地区超基性、基性岩体的圈定起到很好的指导作用,大功率瞬变电磁法和地电化学法组合的应用效果明显,能准确指示隐伏岩体的埋藏深度和性质,地电化学方法在干旱岩屑覆盖区起到很好的示矿效果。     

银纳米粒子的光催化合成

在聚丙烯酸钠溶液中,利用紫外光还原制备银纳米粒子.通过调控光照波长、时间、聚丙烯酸钠质量分数和硝酸银的浓度,获得不同粒径和形貌的银纳米粒子.透射电子显微镜分析表明,合成粒径在50~90nm球形银纳米粒子的最佳实验条件为聚丙烯酸钠质量分数为25%,硝酸银浓度为0.025moL·L-1,365nm紫外光源照射,照射时间4h.