校园邮件系统的研究及搭建

随着校园信息化建设进程的不断加快，越来越多的学校搭建了自己的邮件系统，提供给教师或者学生使用。文中通过对当前市场上的墼往系统产品进行分析，选取出适合校园的邮件系统产品，并结合该产品的特点制订出一个校园邮件系统搭建方案。     

英语听力训练中的几个非语言因素

在英语听力训练中，不断提高对训练的认识、强化训练兴趣，是增强训练的动力所在；采取精听加泛听、掌握语篇理解是训练的方法，注重这些非语言因素的影响有助于提高听力训练质量。     

Preparation and reaction of bis (perfluoroalkanesulfonyl) methyl halides

Halogenation of the potassium or silver salts of bis(trifluoromethanesulfonyl)methane (CF3SO2)2CH2 and its cyclo analogues 1 with N-fluoro-bis(trifluoromethanesulfonyl)imine [(CF3SO2)2-NF], chlorine or bromine gave good yields of the corresponding α-halo disulfone (CF3SO2)2CHX and cyclo analogues 9, 10. The chemical transformation of these fluorinated α-halo-disulfones are described.     

多面体分子轨道的理论方法——Ⅰ、多面体分子轨道构造的一般方法

本文根据轨道性格、提出了构造对称性匹配的多面体分子轨道、中心原子本征态、杂化轨道和定域分子轨道以及计算群重迭积分的统一方法。在这方法中,轨道性格用转动矩阵元表示。     

多面体分子轨道的理论方法——Ⅲ、结构多面体骨架的成键分子轨道

本文论证了封闭硼烷离子B_nH_n~(2-)和碳烷C_nH_n的结构多面体是互为共轭的多面体,它们是棱数相同而面数与顶点数互易的多面体,并应用交替烃图形方法,给封闭硼烷离子的骨架成键分子轨道的Wade“n+I”规则以新的诠释,进而讨论这个规则对金属原子簇多面体结构的有效性。     

低温对动物体细胞的损伤影响

低温保存细胞是最常见的长期保存方法,但低温保存是有条件的,降温过快或过慢及其复温速率都直接影响细胞的存活。综述了降温与复温对动物体细胞的损伤。     

Growth of Semi-Insulating GaN Using N2 as Nucleation Layer Carrier Gas Combining with an Optimized Annealing Time

Semi-insulating （SI） GaN is grown using N2 as the nucleation layer （NL） carrier gas combined with an optimized annealing time by metalorganic chemical vapour deposition. Influence of using 1-12 and N2 as the NL carrier gas is investigated in our experiment. It is found that the sheet resistance of unintentionally doped GaN can be increased from 10^4 Ω/sq to 10^10 Ω/sq by changing the NL carrier gas from 1-12 to N2 while keeping the other growth parameters to be constant, however crystal quality and roughness of the tilm are degraded unambiguously. This situation can be improved by optimizing the NL annealing time. The high resistance of GaN grown on NL using N2 as the carrier gas is due to higher density of threading dislocations caused by the higher density of nucleation islands and small statistic diameter grain compared to the one using 1-12 as carrier gas. Annealing the NL for an optimized annealing time can decrease the density of threading dislocation and improve the tilm roughness and interface of AlGaN/GaN without degrading the sheet resistance of as-grown GaN signiticantly. High-quality SI GaN is grown after optimizing the annealing time, and AlGaN/GaN high electron mobility transistors are also prepared.     

Rough Sets and Nuclear Safety

It is well-known that rough set theory can be applied successfully to rough classification and knowledge discovery. Our work is concerned with finding methods for using rough sets to identify classes in datasets, finding dependencies in relations and discovering rules which are hidden in databases by means of decision tables and algorithm D. We use these methods to analyze and control aspects of nuclear energy generation.     

高校开展野外生存生活训练的障碍因素分析

野外生存生活训练被引入高校课堂刚刚起步，在真正落实方面还存在着诸多问题，无论是从训练手段、教学模式还是人力资源等方面都还存在着不足;但是它又是一项能够充分调动学生积极性、培养其综合素质的运动.因此探讨制约该项运动在高校开展的障碍因素、应对方式以及后续研究的方向，对促进该项运动的积极发展具有现实意义.