现代信息技术在大学英语教学中的应用

从信息技术的发展趋势入手,分析了信息技术在英语教学中的应用现状,提出了进一步加强信息技术与英语教学整合的措施。     

混合氯化稀土催化合成DOP,DOM和DOA

本文报道:价廉的混合氯化稀土,对合成DOP等增塑剂有明显的催化效果。产品精制简单,转化率高,有应用前景。     

浅析地方公共图书馆存在的问题及对策

目前,一些地方公共图书馆落后的组织结构、管理方式以及淡薄的服务意识,已远远不能适应当前社会的需要。针对地方公共图书馆存在的问题,提出一系列改进措施,旨在使地方图书馆更好地为社会公众服务。     

步进电机细分技术在经济型数控机床中的应用

本文叙述了步进电机细分原理及微机控制系统，并将其应用于经济型数控铣床的横向进给伺服系统，有效提高了开环数控系统的定位精度。     

An Improved S-Random Interleaver Design for Turbo Code Based on Chaos Model

A new method to design interleaver based on Henon chaos model is presented. The designed interleaver is with rather random behavior. Experimental results show that the proposed S-henon interleaver make a magnitude of im provement in bit error rate （BER） performance by 0.4 dB compared with the S-random interleaver for AWGN channel respectively. The S-henon interleaver may be adapted to 3G mobile communication systems.     

稀土果糖—高氯酸及稀土—果糖—硼酸配合物的研究

首次合成了镧（Ｌａ）、镨（Ｐｒ）、钕（Ｎｄ）、钐（Ｓｍ）、钆（Ｇｄ）的果糖－高氯酸固体配合物以及Ｌａ,Ｐｒ,Ｎｄ,Ｓｍ,Ｇｄ和Ｅｕ（铕）的硼酸－果糖配合物．利用化学分析,ＩＲ,１ＨＮＭＲ,ＵＶ和热谱等物理化学手段对这两系列共１１个配合物的组成和成键情况进行了表征,并对它们的某些物理化学性质进行了研究．结果表明：稀土－果糖－高氯酸配合物的组成为：ＲＥ３（Ｃ６Ｈ１１Ｏ６）５（ＯＨ）２（ＣｌＯ４）２３Ｈ２Ｏ（ＲＥ＝Ｌａ,Ｐｒ,Ｎｄ,Ｓｍ,Ｇｄ）;稀土－果糖－硼酸配合物的组成为：ＲＥ（Ｃ６Ｈ１２Ｏ８Ｂ）２Ｃｌ２ＣＨ３ＯＨ,（ＲＥ＝Ｌａ,Ｐｒ,Ｎｄ,Ｓｍ,Ｅｕ,Ｇｄ）．     

Structure and stability of endohedral X@Si20H20 complexes (X = Li, Na, K, Be, Mg, Ca)

The structure and stability of endohedral X@Si₂₀H₂₀ complexes (X = Li^0/+, Na^0/+, K^0/+, Be^0/2+, Mg^0/2+, Ca^0/2+) have been studied at the B3LYP/6-31G* level of density functional theory. It is found that complexes with X = Na^0/+, K^0/+, Mg and Ca^0/2+ are energy minimum structures with X at the cage center in I_h symmetry, while those with X = Li^0/+, Be^0/2+, Mg²⁺ have off-centered structures with X towards one pentagon face in C_5v symmetry. Large electron or charge transfer between the Si₂₀H₂₀ cage and the encapsulated X has been observed.     

Stacking due to ionic transport number mismatch during sample sweeping on microchips

Sample stacking can occur in isoconductive buffer systems as a result of ion transport mismatches that cause changes in buffer conductivity during electrophoresis. Fluorescence imaging was used to examine this effect in the sweeping of hydrophobic dyes with sodium dodecyl sulfate (SDS) on microchips. Imaging revealed the occurrence of a stacking effect in a sodium borate buffer system in which the sample buffer and SDS-containing run buffer had the same initial conductivity. Injected sample plugs were first swept by SDS micelles and the swept band was then stacked at the trailing end of the sample zone. This effect is due to changes in conductivity at both the front and back interfaces of the injected sample plug and can be modeled by moving boundary equations. Maximum signal enhancements of 86-, 160- and 560-fold were obtained for Rhodamine 560, Rhodamine B and Rhodamine 6G, respectively, by the combination of sweeping and stacking within a 1 cm section of microchannel. Based on sample sweeping/stacking and manipulation of the electric field polarity, a method of trapping and concentrating analyte from multiple injections was also demonstrated.     

城市化与第三产业的协调发展

随着中国经济的持续发展,中国的城市化进程开始加速,城市化的快速发展需要第三产业尤其是信息服务业的发展作为支撑,反过来第三产业的发展又促使城市档次的进一步提升,城市化进程和第三产业的发展是一个互动的过程,城市化与第三产业协调发展是今后中国经济发展的有力保障.     

基于XML的Web数据交换服务平台的设计与实现

依托Web提出了一种以XML文件作为中间结果实现异构平台数据交换的解决方案，满足了电子政务处理过程中对不同形式数据的处理要求．