产生惰性气体高价离子的新方法

此文介绍了一种产生惰性气体高价离子的新方法。在飞行时间质谱仪（ＴＯＦ－ＭＳ）上，把聚焦后的３０８ｎｍ激光掠射到不锈钢栅网上，产生超短脉冲的电子束，利用这种电子束来轰击惰性气体（Ｈｅ，Ｎｅ，Ａｒ，Ｋｒ，Ｘｅ），产生高价离子，并给出了这些离子的飞行时间质谱。这些高价离子可能是电子逐次电离气体原子产生的。这种方法可作为飞行时间质谱的一种理想的“软电离”的“点”离子源     

高温云纹干涉法的进展

本文对云纹干涉法在高温范围的测量应用进行了回顾。对制栅方法、高温云纹干涉光路系统及高温云纹干涉法在材料高温蠕变测量、高温蒸气管道现场蠕变测量、激光焊接残余应变分析等中的应用进行了简述     

电子直线加速器磁控管工作频率的稳定

 介绍一种利用谐振腔输出能量-输入频率关系作为鉴频方法的稳频系统，由于将谐振腔输出信号进行积分保持，降低了高压脉冲对系统的干扰，也提高了频率稳定度。系统中采用了高频率步进电机伺服子系统，使功耗大为减少系统工作频率为2856MHz，不稳定度不大于± 7×10^-6。     

离子组态效应对电子传导不透明度的影响

基于相对论Hartree-Fock-Slater 自洽场原子结构模型, 考虑电子-离子间的弹性散射机制, 用分波法和扩展的Ziman 公式对电子传导不透明度作了计算。考虑到等离子体离子环境的影响, 不仅引进了等离子体的结构因子, 而且更细致地考虑了等离子体内离子类型 (组态) 对电子传导     

十六烷基吡啶在玻碳电极表面上的吸附过程

本文用交流阻抗法在长光程薄层光谱电解池中研究了溴化十六烷基吡啶(CPyBr)在玻碳电极上的吸附过程。在复数平面图的高频区获得了与电解池结构电容有关的半圆,低频区获得了与CPyBr吸附有关的阻抗及Warburg阻抗,建立了CPyBr的单分子层吸附模型及电极过程的交流阻抗等效电路。理论预测与实验数据吻合较好。     

Effect of 2-Selenium Bridged β-Cyclodextrin, Glutathione Peroxidase Mimic on Stroke of Stroke-prone Spontaneously Hypertensive Rats

IntroductionStrokeisthemaindiseasethatbringsdeathormakesthepatientssufferfromlongtermdisability .Everyyearthereareabout 5millionpeopledeadfromstrokeallovertheworld .Fortheincreaseofelderlypopulationintheworld ,fewillnessesaremoredread edthanstroke[1] .Elevatedblood pressurehaslongbeenrecognizedasoneofthemostimportantlydan gerousfactors .However ,thereisincreasingevidencethatfamilialpredisposition ,orhereditaryfactors ,mayplayasignificantroleintheetiologyofstroke :strokehasbeenfoundtoshowfamil…     

Enzymatic Synthesis of a CCK-8 Tetrapeptide Fragment

The enzymatic synthesis of a tetrapeptide Phac-Met-Gly-Trp-Met-OEt is reported. It was synthesized by coupling Phac-Met-OEt with Gly-OMe. HCI, Trp-OMe and Met-OEt successively, catalyzed by α-chymotrypsin, papain and α-chymotrypsin respectively. The results of FAB-MS showed that the products had the correct molecular mass.     

A New Taxoid from Leaves and Branches of Taxus chinensis

A new taxoid, 2-deacetyl-2α, 14β-dihydroxybaccatin Ⅳ (1), was isolated from the leaves and branches of Taxus chinensis together with the known compound baccatin Ⅳ (2). The structure of the new compound was elucidated by spectroscopic techniques. The detailed ^13C NMR assignments of baccatin Ⅳ are reported for the first time.     

Coke precursor as an intermediate during the alkylation of isobutene/butene over a solid superacid

~~Coke precursor as an intermediate during the alkylation of isobutene/butene over a solid superacid~~     

MELLIN TRANSFORM IN WEAK FUNCTIONS AND M(?)NTS FORMULA

In this paper,the authors introduce some Mellin transforms in weak functionsand discuss their applications to Munts formula of the Riemann zeta-function.