Solution conformational preferences of glutaric, 3‐hydroxyglutaric, 3‐methylglutaric acid,and their mono‐ and dianions

Conformational preferences of glutaric, 3‐hydroxyglutaric and 3‐methylglutaric acid, and their mono‐ and dianions have been investigated with the aid of NMR spectroscopy. In contrast to succinic acid, glutaric acid displays essentially statistical conformational equilibria in polar and non‐polar solutions of high and low hydrogen‐bonding ability with no clear evidence for intramolecular hydrogen‐bonding interactions. The acid ionization constant ratios, K ₁/K₂, in D₂O and DMSO of glutaric, 3‐hydroxyglutaric, and 3‐methylglutaric acids also indicate that intramolecular interactions are much less important than, or indeed insignificant, for shorter‐chain acids. FTIR studies on 3‐methylglutaric acid indicate some preference for either association with solvent or dimerization, depending on the solvent, rather than intramolecular hydrogen bonding. Copyright © 2008 John Wiley & Sons, Ltd.     

由游离的三氨基胍在非水溶剂中合成TAZ

由游离的三氨基胍和叠氮酸在非水溶剂中合成三氨基胍叠氮酸盐（ Ｔ Ａ Ｚ）,其结构由元素分析、质谱（ Ｍ Ｓ）和 Ｉ Ｒ谱所证实     

校园网络数据资源分层访问策略

分析了校园ＭＩＳ及数据资源的特征,针对校园信息资源范围广、关联复杂的状况,提出了数据资源统一访问策略——分层访问．数据访问分为七层,各层完成数据访问独立性的特定功能,使不同的访问软件能透明访问全部数据资源．为保证传统应用能基于网络计算访问统一数据资源,又提出了“数据访问管道”和数据库访问服务器的技术．文章分析了以应用服务器为基础的Ｎ－Ｔｉｅｒｓ计算的弊端,设计了“虚拟应用服务器”ＷＵＶ－ＡＰＰＳ,将数据访问对象构造成数据对象组件．     

RELAXATION AND EXISTENCE IN NONISOTROPICAL PLASTICITY PROBLEMS

Giving a nonisotropic plasticity problem on a Sobolev Space, the author tries to relax it to a new problem whioh is posed on a subset of BD (Ω). It is proved that this relaxation does not change the equilibrium energy and that the solutions exist in such settings under not too restricted conditions.     

NH3的同步辐射光电离

用同步辐射光在１０．０－１１．８ｅＶ能量范围内测量了ＮＨ３的光电离效率曲线，观察到在台阶状的离子振动谱上叠加了丰富的自电离结构。通过相应振动结构分析，得到ＮＨ３分子离子基电子态的振动波数ωｅ和非谐性常数（ωｅχｅ），对于出现的自电离结构可归类于ｎｓａ１（ｎ＝５，６），ｎｐａ１（ｎ＝５，６）和ｎｐｅ（ｎ＝６，７）Ｒｙｄｂｅｒｇ系列。     

基于PC机的虚拟现实技术研究

本文利用所需额外硬件很少的立体显示技术,研制了一种基于微机平台的虚拟现实系统。这个系统利用最新推出的微机版的三维图形标准Open GL建模,以实时动画形式实现了真正的交互性,立体视觉效果明显,可以给观赏者提供真实的临场感和亲自控制的参与感。与已研制出的“三维立体显示系统”相比,有了实质性的进步。     

Image guide couplers used in millimeter wave integrated circuits

The dispersion and coupling characteristics of the coupled image guides are studied by using the odd-even mode principle and effective dielectric constant method. The practical design of the image guide directional couplers is presented. The experiments of 3-dB and 10-dB couplers in ka band show several good features which are very useful to millimeter wave integrated circuits with flat coupling, easy design and fabrication, mechanical stability and low losses.     

A New Reagent for the Reduction of N-Arylsulfonylimines

Potassiumselenatedborohydride(KBHZSe3),sodiumselenatedborohydride(NaBHZSe3)werepreparedfirstbyLalancetteetall.However,sincethen,therehavebeenlittlereportabouttheirapplication.Wehaveusedpotassiumselenatedborohydrideinformamidetoreducearomaticnitrocompounds,andsuccessfullyobtainedthecorrespondinganilines2.Inaddition,wehavealsoreportedthereductionofarylsulfonylchloridestothecorrespondingdisulfidesbysodiumselenatedborohydriderefluxinginCH,CN'.Fromourresearchwork,KBHZSe3andNaBHZSe3werefou…     

环戊叉基环戊酮的烷基化反应研究

研究了环戊叉基环戊酮与不同类型烷化剂的反应规律；讨论了不同催化剂对烷基化反应的催化性能，发现ＮａＮＨ２和ＮａＨ具有较好的催化作用；讨论了烷基化产物的结构，证实了烷基化反应发生在羰基的α双键碳原子上。