茂金属配合物[(eta5-C5H4 Si2 Me5)Mo-Br(CO)3]的电子结构研究

运用G98W，采用Lan12dz基组，对茂金属配合物[eta^5-C5H4Si2Me5)Mo-Br(CO)3]进行从头算研究，探讨配合物结构单元的稳定性，分子轨道能量，原子净电荷布局规律，以及一些前沿分子轨道的组成特征等，结果表明，标题配合物结构在能量上是稳定的，作为结构单元而存在，为茂金属配合物的合成，分子组装分析提供参考。     

晶体结构特征对其能谱结构的影响

本文从晶体的结构特征平移对称性出发，得到了平移算符的本征值方程——布洛赫定理、晶体中电子的哈密顿算符的本征函数——布洛赫函数和晶体的能带结构，并阐明了晶体结构特征导致了晶体能谱结构的形成。     

工程结构中非线性动态失稳与分叉理论

In civil engineering, the nonlinear dynamic instability of structures occurs at a bifurcation point or a limit point. The instability at a bifurcation point can be analyzed with the theory of nonlinear dynamics, and that at a limit point can be discussed with the theory of elastoplasticity. In this paper, the nonlinear dynamic instability of structures was treated with mathematical and mechanical theories.The research methods for the problems of structural nonlinear dynamic stability were discussed first, and then the criterion of stability or instability of structures, the method to obtain the bifurcation point and the limit point, and the formulae of the directions of the branch solutions at a bifurcation point were elucidated. These methods can be applied to the problems of nonlinear dynamic instability of structures such as reticulated shells, space grid structures, and so on.     

如何提高英语四、六级的作文分数

写作是大学英语教学的难点之一,也是四、六级考试的重点之一。笔者认为在考试中,书写工整漂亮、词汇标新立异、造句与众不同以及布局独树一帜可以帮助考生提高四、六级的作文分数。     

液晶与它的显示功能

液晶是介于液态与结晶态之间的一种物质状态,它既有液体的流动性,又具有晶体的各向异性。利用其电光效应,可实现对数字、图象的显示。     

晶体管H参数微变等效电路研究

分析晶体三极管三种组态电路H混合参数，用不同方法导出共集、共基放大电路H参数和更精确的共集电极及共基电极晶体三极管H参数与其共发射极组态H参数的关系，说明不同组态电路有相同的电路形式。     

Opportunity structures and educational marginality: the post-16 transitions of young people outside education and employment

This paper reports on findings from a three-year ethnographic study of 24 young people in northern England who were classified as not in education, employment or training (NEET), or at risk of becoming so. Drawing on conceptions of opportunity structure and educational marginality, the paper discusses the processes leading to young people becoming NEET after leaving school. It presents findings concerning the family backgrounds, school experiences, and educational attainment of participants, and traces their initial post-16 destinations and their pathways to NEET status. Although most participants did not become NEET immediately after leaving school, restricted labour market opportunities and a lack of high-quality education and training for middle- and low-attaining young people exacerbated social and educational disadvantage. Over time, participants became increasingly restricted to marginal forms of learning. The paper argues that a focus on opportunity structures provides a powerful way of understanding these processes, and that alongside sustained NEET status, educational marginality should be of equal concern to policy makers.     

对硝基苯腙基取代丙二酸二乙酯的合成及晶体结构

在冰盐浴条件下,对硝基苯胺重氮盐与丙二酸二乙酯反应,合成了标题化合物C_(13)H_(15)N_3O_7。经IR、~1HNMR、元素分析和X-射线单晶测定,确认了其结构。化合物属单斜晶系,C2/c空间群,晶胞参数:α=14.331(11)■,b=6.847(5)■,c=32.63(3)■,β=98.149(14)°,V=3169(4)■~3,Z=8,D_c=1.364Mg/m~3,μ=0.112 mm~(-1),F (000)=1360,R=0.0783,wR=0.2461。     

检察机关的结构与功能分析

检察制度的改革是我国司法改革的重要组成部分。检察制度的改革必须以检察机关的结构与功能为基础．通过技术系统、管理系统与制度系统的结构分析，以及社会控制、保证规范实施和促进纠纷解决的功能分析，以期人们能把握检察机关的结构与功能，从而对其改革有所裨益。     

从野生植物三颗针中提取黄连素

对用水做溶剂从野生植物“三颗针”(又名黄牛刺 )中提取黄连素的小规模作坊式生产方法进行了探索。采取循环法提取 ,可提高黄连素产率和纯度。这为川西北山区人们利用当地野生植物资源提供了一条合理生产途径 ,具有较好的经济效益和社会效益。