流动系统中鲁米诺电生化学发光(ECL)系统研究初探

本文描述了一个新的鲁米诺电生化学发光流动系统.通过微铂电极流动池,H2O2被还原为OH-以维持鲁米诺化学发光所要求的pH条件.本文对鲁米诺化学发光机理进行了初步探讨,并详细研究了ECL的最佳条件,该系统明显降低了反应噪声,优于混合反应系统,可作为液相色谱间接测定检测器.     

基于MCM-41分子筛表面的镱离子印迹聚合物的制备及其性能

运用离子印迹技术,以3-氯丙基三乙氧基硅烷为锚定剂,将功能单体直链聚乙烯亚胺(PEI)接枝在MCM-41分子筛表面,选择镱离子作为模板离子,以环氧氯丙烷交联制备出基于MCM-41表面的镱离子印迹聚合物Yb(Ⅲ)-IIP-PEI/MCM-41,并以同样的方法制备非离子印迹聚合物(NIP-PEI/MCM-41)。 利用傅里叶变换红外光谱仪和扫描电子显微镜等技术手段对Yb³⁺印迹聚合物进行表征,采用静态吸附法确定了Yb(Ⅲ)-IIP-PEI/MCM-41对Yb³⁺的最佳吸附条件及选择性吸附性能。 结果表明,Yb(Ⅲ)-IIP-PEI/MCM-41和NIP-PEI/MCM-41的最大吸附量分别为229.93和99.27 mg/g;印迹材料对Yb³⁺的吸附符合Langmuir模型;吸附平衡在40 min的时候基本可以达到,可以利用准二级动力学模型来描述其吸附过程;Yb(Ⅲ)-IIP-PEI/MCM-41对Yb³⁺具有较强的选择性,同时也具有很好的重复使用性能。 成功地将MCM-41和离子印迹聚合物的优点结合起来,制备出一种对稀土Yb离子既有高吸附量又有高选择性的吸附材料,为进一步将其应用在处理实际废水,分离回收低浓度稀土废水中的稀土元素等方面打下了基础。     

New Temperature Integral Approximate Formula for Non-isothermal Kinetic Analysis

A new approximate formula for temperature integral is proposed. The linear dependence of the new fomula on x has been established. Combining this linear dependence and integration-by-parts, new equation for the evaluation of kinetic parameters has been obtained from the above dependence. The validity of this equation has been tested with data from numerical calculating. And its deviation from the values calculated by Simpson's numerical integrating was discussed. Compared with several published approximate formulae, this new one is much superior to all other approximations and is the most suitable solution for the evaluation of kinetic parameters from TG experiments. This revised version was published online in August 2006 with corrections to the Cover Date.     

Approximate formulae for calculation of the integral òT0Tmexp(-E/RT)dT

Summary In this paper two approximate formulae have been developed for calculation of the integral ò^T₀T^mexp(-E/RT)dT by using integration-by-parts approaches. They are in the following forms: I(m,T) = (RT^m+2)/(E+(m+2)RT)exp(-E/RT) I(m,T) = (RT^m+2)/(E+(m+2)(0.00099441E+0.93695599RT)exp(-E/RT) The validity of the two formulae has been confirmed and their accuracies have been tested with data from numerical calculating. In contrast to existing other integral methods, both the present approaches are simply used, accurate, and can be used for arbitrary values of m.     

同步荧光光谱分析中几个问题的探讨

通过实验阐明了同步荧光光谱与普通荧光光谱之间的关系，在此基础上讨论了溶剂散射光对同步荧光分析的影响以及同步荧光分析的灵敏度。     

Enthalpy change and mechanism of oxidation of o-phenylenediamine by hydrogen peroxide catalyzed by horseradish peroxidase

The hydrogen peroxide-oxidation of o-phenylenediamine (OPD) catalyzed by horseradish peroxidase (HRP) at 37 °C in 50 mM phosphate buffer (pH 7.0) was studied by calorimetry. The apparent molar reaction enthalpy with respect to OPD and hydrogen peroxide were −447 ± 8 kJ mol⁻¹ and −298 ± 9 kJ mol⁻¹, respectively. Oxidation of OPD by H₂O₂ catalyzed by HRP (1.25 nM) at pH 7.0 and 37 °C follows a ping-pong mechanism. The maximum rate V_max (0.91 ± 0.05 μM s⁻¹), Michaelis constant for OPD K_m,S (51 ± 3 μM), Michaelis constant for hydrogen peroxide Km,H₂O₂ (136 ± 8 μM), the catalytic constant k_cat (364 ± 18 s⁻¹) and the second-order rate constants k₊₁ = (2.7 ± 0.3) × 10⁶ M⁻¹ s⁻¹ and k₊₅ = (7.1 ± 0.8) × 10⁶ M⁻¹ s⁻¹ were obtained by the initial rate method.     

溴化四-(4-N,N,N-二甲基,正庚烷基氨基苯基)卟啉钴的合成,L-B膜及其气敏、湿敏特性

卟啉和酞菁是一类大环共轭化合物,由于其结构和性能以及在生命科学中所起的作用,使得用L-B膜技术研究其结构和功能越来越引起人们的重视.自从Jones等发现原卟啉L-B膜具有较好的光导性以来,卟啉L-B膜的电导性和气体敏感特性相继有人进行过研究。发现卟啉铜L-B膜对二氧化氮有很高的敏感性,而且有良好的选择性.人工合成的     

Silver‐Catalyzed Formal Insertion of Arynes into RfI Bonds

An unprecedented silver‐catalyzed formal insertion of arynes into R_f?I (R_f=CF₃, C₂F₅) bonds has been developed. This protocol provides easy access to various ortho‐perfluoroalkyl iodoarenes under mild conditions. In this insertion reaction, an ionic atom‐transfer reaction of R_fI occurs, and a silver‐mediated metathesis process is involved in the efficient transfer of the electropositive iodine atom.