New Approach to Detecting Phenoxyl Free Radicals Generated in Enzyme Reaction by Stopped-flow Spectrophotometry

Quantification of free radical formation is critical for evaluation and interpretation of many radical-mediated biological processes1-4. Numerous studies have been devoted to the determination of free radicals, but the most of the reports have been focuse…     

醛的自氧化振荡反应

1983年 Jensen 与 Roelofs 等报道了苯甲醛自氧化反应中出现的化学振荡现象。我们还观察到苯甲醛、取代苯甲醛和许多脂肪醛的自氧化振荡反应,实验方法与文献[3]相似。反应在具有电磁搅拌的恒温反应器中进行,以醋酸水溶液(冰醋酸与水的体积比为9∶1)和     

压力流驱动电色谱分析方法及其若干色谱行为

压力流驱动电色谱分析方法是一种新型色谱技术。它组合了ＨＰＬＣ和电泳两种技术，为分离提供了更多可控制的因素。介绍了压力流驱动电色谱的装置和毛细管电色谱柱的装置方法，从理论上讨论了影响电色谱分离的因素并用实验数据加以证明。最后尝试性地将电色谱法用于测定香蕉样品中萨索啉（Ｓａｌｓｏｌｉｎｏｌ）等的含量。     

BAYER COUNTER CURRENT SYSTEMS IN COMPARISON WITH CONVENTIONAL CO—CURRENT SYSTEM IN THE FIELD OF WATER TREATMENT

From an economical point of view both the quality of the ion exchange resins and the technology used in the field of industrial water treatment are important for a successful performance.In general,two different technologies have been established on the market:The main differneces between the CO-and counter current technologes will be discussed and data concerning the requirement of chemicals for regeneration and the quality of the deionized water will be opposed.In addition several different varieties of the modern counter current technologies,developed and patented by Bayer AG,will be described and the advantages,depending on the application and the demand on the quality of the deionized water,pointed out .In view of stronger regulations concerning the consumption of regeneration chemicals,and waste water,and also because of the superior quality of the produced water,the market share of counter current technologies will continue to increase world-wide.     

Identification of Different Cobalt Nucleation on Glassy Carbon

The nucleation mechanisms of cobalt from sulfate solutions were studied by utilizing the electrochemical technique, chronoamperometry. It was found that the recorded current-time transients introduced from 1.0mol/L CoSO4 solution were complexes with unusual shapes. All characteristic features were identified as separate process. The instantaneous or progressive nucleation with 2D or 3D growth exists during the cobalt deposition, depending on the applied potentials.     

阿拉伯糖和丙酮作混合底物的B—Z振荡反应

化学振荡反应在近年来得到了广泛的研究,研究由组成生命体的物质参与的振荡器对探索生命运动中的振荡规律具有重要意义。本文报道由糖类参加的B—Z体系:阿拉伯糖(以Ara表示)—丙酮(以Act表示)—BrO_3~--Mn~(2+)—H_2SO_4体系。并对振荡反应中二种有机物的作用作了初探。实验部分     

导数振荡与应变能极小的平面分段三次参数Hermite插值

由于分段三次参数Hermite插值的切矢往往被作为变量,故可对其进行优化以使得构造的插值曲线满足特定的要求.为了构造兼具保形性与光顺性的平面分段三次参数Hermite插值曲线,给出了一种通过同时极小化导数振荡和应变能来确定切矢的方法.首先以导数振荡函数和应变能函数为双目标建立了切矢满足的方程系统;然后证明了方程系统存在唯一解,并给出了解的具体表达式;最后给出了误差分析,并通过数值算例表明方法的有效性.结果表明,相对于导数振荡极小化方法和应变能极小化方法,所提出的导数振荡和应变能极小化方法同时兼顾了平面分段三次参数Hermite插值曲线的保形性和光顺性.     

曲率流的参数化有限元逼近

许多物理现象可以在数学上描述为受曲率驱动的自由界面运动,例如薄膜和泡沫的演变、晶体生长,等等.这些薄膜和界面的运动常依赖于其表面曲率,从而可以用相应的曲率流来描述,其相关自由界面问题的数值计算和误差分析一直是计算数学领域中的难点.参数化有限元法是曲率流的一类有效计算方法,已经能够成功模拟一些曲面在几类基本的曲率流下的演化过程.本文重点讨论曲率流的参数化有限元逼近,它的产生、发展和当前的一些挑战.     

味觉电化学传感器的研究

本文以十六烷基三甲基溴化铵＋乙醇／含苦味酸的１．２－二氯乙烷／蔗糖水溶液为研究体系，对影响该体系电位振荡 各因素进行了探讨，发现各有味物质均能影响该体系的电位振荡。初步建立了测定有味物质的演性定量方法对辣椒素进了定量测定。对该味觉电化学传感器产生振荡及辣椒素响应机理进行了探讨。     

Cr_2O_7~(2-)对B-Z振荡反应的影响及其分析应用

研究了Cr2O72-对B-Z化学振荡反应的影响.结果表明,Cr2O27-的加入明显改变该振荡反应的诱导期,且诱导期的改变值Δtin与所加入Cr2O72-的浓度有良好的线性关系,线性范围3.45×10-6~6.20×10-4mol·L-1,相关系数为0.9992,对Cr2O72-扰动B-Z振荡反应的机理进行了探讨.