基于阳离子共轭聚合物比色检测HIV逆转录酶的RNase H活性

利用阳离子聚噻吩衍生物与单链DNA和杂合体DNA/RNA通过静电相结合时所产生的紫外吸收变化,建立了一种检测HIV逆转录酶(RT-HIV)的RNase H活性的方法。阳离子聚噻吩衍生物的紫外吸收最大波长位于短波385nm,与单链DNA结合会使聚噻吩衍生物的紫外吸收最大波长红移至525nm;而与杂合体DNA/RNA结合时对其紫外吸收最大波长几乎没有影响,当利用RT-HIV的核糖核酸酶RNase H活性水解掉杂合体中的RNA时,杂合体溶液又会使聚噻吩衍生物的紫外吸收最大波长发生红移。结果表明,紫外吸收最大波长变化明显,甚至直观用肉眼就可以观察到杂合体水解前后溶液颜色的变化。同时还测定了不同时间下RNase H酶水解杂合体中RNA的吸光度变化曲线,计算出了RNase H酶水解的动力学常数和最大初速度。     

超高速撞击Kevlar纤维布填充防护结构研究

 利用二级轻气炮,对Kevlar纤维布填充Whipple防护结构进行了超高速撞击实验研究。基于Nextel/Kevlar撞击极限曲线,分析了单层及双层Kevlar纤维布填充防护结构的防护性能以及填充材料、舱壁的损伤情况。实验表明,Kevlar纤维布填充Whipple防护结构在低速区具有优良的防护性能。分层布局可改善Kevlar纤维布填充Whipple防护结构在低速区的防护性能。在低速区,Kevlar纤维丝主要依靠大量的塑性变形及断裂吸收弹丸的动能;在高速区,Kevlar纤维丝存在高温熔化及碳化现象,使弹丸破碎或熔化为更小的碎片或熔球,从而减轻对舱壁的损伤。     

Hydrogenic systems,frequency standards and fundamental constants

Hydrogenic (two-body) systems are the only atomic systems for which uncertainties in calculations of the energy levels approach the current state of the art in frequency measurement. This article discusses progress in the theory and measurement of transition frequencies in hydrogenic systems. These studies have relevance to the determination of fundamental constants and the testing of physical theories, especially quantum electrodynamics. A set of high accuracy calculable frequency standards could also be realized by using hydrogenic systems.     

Photophysics of Genistein isoflavone: Solvent and concentration effects studied by UV–visible spectroscopy and theoretical simulation

Genistein isoflavone is shown to exist in two different conformations which are the 90° completely twisted geometry and the 50° less twisted one. Specific interactions with the solvent cage as well as self-association processes seem shifting the isoflavone from the perpendicular conformation towards the less twisted one. The theoretical simulation, using analytical atom–atom pair potential, predicts a self-dimer in a slipped non-sandwich, face to river, perpendicular structure. From the UV–visible photophysics investigations it is revealed that monomeric species cannot exist alone even at very low solute concentration (10⁻⁶ M), the self-association process occurs already in this concentration range.     

基于模糊积分的Fisher判别分析

文中引进一种新的非线性判别分析-基于Choquet模糊积分的Fisher判别分析,该基于Choquet模糊积分的Fisher判别分析方法可充分考虑到输入的各指标之间的交互作用,当模糊测度μ具有可加性时,基于Choquet模糊积分的Fisher判别分析方法就是经典的Fisher判别分析.最后将此方法应用于心肌梗死的鉴别诊断.     

常温预辐射聚合法物理包埋葡萄糖氧化酶的研究

Most of bioactive species such as enzyme and antibody will be damaged and lose part of their bioactivity when they are irradiated by ionizing radiation at room temperature. Low temperature could somewhat control the effect, so kaetsu and his co-workers developed an entrapping technique at low temperature ( - 78℃). On the other hand, some enzymes such as catalase and house radish peroxidase have so-called radiation-induced post-deactivation effect as well. In order to avoid the trouble in performance and loss of bioactivity, a physical ent-rapping of bioactive species via preirradiation polymerization at room temperature were deve-loped in the Authors'lab. In this work we developed this technique. The glucose oxidase was entrapped in polyacrylamide hydrogel ind uced by pre-irradiation. Experiments under several different conditions such as absorbed dose and concentrations of enzymes,monomer and crosslinking agent were carried out. The results showed that this technique can be used ex-tensively in various enzyme.     

超分子化合物[H3N(CH2)3NH3]•[Pb2(SIP)2]•6H2O的水热合成与表征

在水热条件下, 用NaH2SIP与Pb(Ⅱ)盐, 以1,3-丙二胺(1,3-PDA)作为结构导向剂进行反应, 得到化合物[H3N(CH2)3NH3]•[Pb2(SIP)2]•6H2O(1). 同时采用单晶X射线衍射、X射线粉末衍射、元素分析、红外光谱和荧光光谱对化合物1进行了表征.     

Ultraviolet-visible spectroscopic study of 3,5-dithio-2,7-dimethyl-[1,2,4]-triazepine: qualitative analysis of tautomeric behaviour

Room temperature UV-vis absorption spectra of the tautomeric system 3,5-dithio-2,7-dimethyl-[1,2,4]-triazepine in solution, in acetonitrile (CH3CN), are measured at different water volume percentages. The comparison of the obtained measures to the calculated allowed absorption transitions, using ZINDO/S package, reveals the coexistence of all the tautomeric forms in aprotic polar solution with a high dominance of the dithione form. The solute-water hydrogen bond, which seems to be of 1:n-type, favours the dithiol and monothiol conformers to the detriment of the dithione one. Further experimental investigations lead to the result that standing at ambient Laboratory conditions in the dark favours the dithione tautomeric isomer, while standing at indirect sunlight shifts the tautomeric equilibrium away from this species.