大学物理教学中量纲分析与应用

量纲分析是重要的半定量分析方法之一,在大学物理教学实践中,要培养和倡导学生在学习中灵活应用量纲分析解决问题,使教学更丰富和直观.本文介绍量纲分析的基本理论及怎样将量纲分析方法贯穿于教学中.     

Cl+F2→ClF+F和F+ClF′→ClF+F′反应机理的密度泛函理论研究

用密度泛函理论(DFT)B3LYP方法, 在6-311G基组下,计算研究了反应Cl+F2→ClF+F和对称反应F+ClF′→ClF+F′的机理。求得前者的过渡态为三角形,活化能为15.57 kJ*mol-1;后者的过渡态为线形和三角形,活化能分别为11.52和196.25 kJ*mol-1。结果均经过振动分析和IRC计算验证。     

激光雷达扫描方式

为实现激光束对空域的有效扫描和探测,研究了栅形扫描、李萨茹形扫描、螺旋形扫描和六边形扫描四种常见的激光雷达扫描方式,推导了相应的扫描方程,讨论了参数的物理意义及调整方法;重点研究了栅形扫描和六边形扫描方式下光斑的分布情况,通过仿真分析了两种扫描方式下光束的漏扫率和重叠率,结果表明,在相同扫描条件下六边形扫描方式的漏扫区域最少。展示了基于上述研究内容的扫描控制系统实物图及扫描图案。分析总结了四种扫描方式的特点,给出了每种扫描方式的适用情况及使用建议。

     

光纤通信用的发光管非线性P-I特性分析研究

本文综合分析了作者从制造光纤通信用的GaAs-GaAlAs发光二极管(LED)到应用这些LED制作端机系统所遇到的P-I非线性特性。文中深入地讨论了P-I非线性特性产生的原因及它对光信号失真的影响,并提出了解决办法。     

双—（磷酸二甲酯）合锌的结构与光谱

由四圆衍射仪收集标题化合物Zn(DMP)_2的衍射数据。用直接法解出其单晶结构为:空间群Pc,a=0.9361(2),b=1.0519(3).c=1.2028(2)nm. β=91.01(2)°,Z=4.锌原子与4个配体的非酯氧原子形成ZnO_4四面体。具有近似的T_d对称性。相邻锌原子由“O—P—O”桥相连,形成一维链状配位聚合物。红外光谱证实O—P—O基的形成。对某些重要的谱带进行了解释,说明了Zn—O振动与配位阴离子振动的混合情况。     

Characterizations of second iterated line graphs

The main results of this paper are two characterizations of second iterated line graphs, i.e., two sets of necessary and sufficient conditions for the existence of solutions to the graph equation H = L²(G). A method to get a root of the graph equation is also given if one exists.     

二氧化锡气敏材料的研究进展

采用纳米技术及对纳米级粉体材料的掺杂，可实现对二氧化锡本体材料的改性，很大程度上提高二氧化锡气敏材料的灵敏度和选择性，本文综述二氧化锡气敏材料的制备及应用进展。     

A theoretical study of electronic excited states of photosynthetic reaction center in Rhodopseudomonas viridis

As well known,photosynthesis is the most impor-tant biochemical process on the earth.With a few mi-nor exceptions,photosynthesis is the only mechanism by which an external source of energy is harnessed by the living world.As a crucial composition of photo…     

二氧化锡纳米粉末的热处理与微结构

采用溶胶－凝胶法制得了二氧化锡干凝胶粉体，并在不同温度下热处理得到不同粒径的二氧化锡纳米级超微粉，采用热重法和差热分析，Ｘ－射线粉天衍射，透射电镜等方法观察了不同温度热处理后纳米粉体的途径，形貌，聚集状态等的变化。     

The connective eccentricity index of graphs and its applications to octane isomers and benzenoid hydrocarbons

The connective eccentricity index (CEI) of a graph G is defined as , where ε_G(.) denotes the eccentricity of the corresponding vertex. The CEI obligates an influential ability, which is due to its estimating pharmaceutical properties. In this paper, we first characterize the extremal graphs with respect to the CEI among k-connected graphs (k-connected bipartite graphs) with a given diameter. Then, the sharp upper bound on the CEI of graphs with given connectivity and minimum degree (independence number) is determined. Finally, we calculate the CEI of two sets of molecular graphs: octane isomers and benzenoid hydrocarbons. We compare their CEI with some other distance-based topological indices through their correlations with the chemical properties. The linear model for the CEI is better than or as good as the models corresponding to the other distance-based indices.