液/液界面的电化学阻抗谱测量 Ⅱ: 液/液界面上离子传递的研究

本文成功地运用四电极系统阻抗谱技术来研究液/液界面上的离子传递。提出了从表观阻抗曲线获取真实界面阻抗曲线的方法。并用此方法对四甲铵离子在水/硝基苯界面上的传递进行了实际的动力学研究, 证实了四甲铵离子在水/硝基苯界面上的传递是可逆离子传递。     

Investigation of Synthesis and Ionic Conductivity of Na5Ysi4O12

Single-phase Na₅YSi₄O₁₂(NYS) was prepared by both conventional solid state reaction and sol-gel process. The formation of NYS was monitored by means of X-ray diffraction (XRD) and scanning electron microscope(SEM) techniques. The thermal stability of major impurity phases corresponding to different polymerization states of silicon was discussed. The conditions for preparing single-phase NYS ceramic with a high ionic conductivity were given.     

THE BOUND STATES AROUND THE DOPANTS I N POLYACETYLENE

The electron bound states caused by dopants in plyacetylene are investigated. When the dopant sits nesr the double bond, there will be two bound states in the gap for positive U and outside the bands for negative U. Whereas when the dopant is absorbed at the single bond, four bound states are formed, two of them in the gap and the other too outside the bands.     

ELECTRONIC STRUCTURE OF BIMETALLIC LAYERED SYSTEMS WITH RANDOMNESS IN LAYER THICKWESSESⅠ. CPA STUDY OF A SIMPLE MODEL

The influence of randomness in layer thicknesses in a blmetallic layered system, i.e., of randomness in the "modulation period" of a,bimetallic "superlattice" on its electronic structure is studied in terms of a simple model in the coherent potential approximation (CPA).Numerical examples are presented for illustration.     

Ag-Pd合金的催化性质,磁性质和价电子状态的研究

用x射线衍射、磁性测量、流动法催化活性测定和X射线光电子能谱等方法,研究了一系列Ag-Pd合金的催化性质、磁性质和价电子状态.当合金中Pd的原子百分含量小于40％时,甲醇氧化脱氢反应的主要产物为甲醛;大于40％时,主要产物变为CO和H_2;与此同时,合金由逆磁性变为顺磁性,Fermi面处的能级密度迅速增加,合金中Pd的d带宽度和不对称性也发生相应的变化,结果表明,Ag-Pd合金的催化性质和磁性质与价带电子状态密切相关.     

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分析了耐磨胶粘涂层基体与填充微粒间的微观热应力．结果表明,基体中热应力在相间界面达最大值;温差还可能导致基体屈服并导致界面脱粘．     

DNA-modified electrodes (Ⅶ)——Preparation and characterization of DNA-bonded and DNA-adsorbed SAM/Au electrodes

Two kinds of DNA-modified electrodes were prepared by covalent and adsorptive immobilization of DNA onto self-assembled monolayers of 2, 2'-dithiodiethanol on gold electrodes and characterized by cyclic voltammetry, Xray photoelectron spectroscopy and scanning tunneling microscopy. The results suggest that the methods are satisfactory for the immobilization of DNA on electrodes.     

丁苯橡胶的阳离子环化

应用一氯二乙基铝和苄基氯催化剂体系进行了丁苯橡胶的阳离子环化反应。研究了反应温度、苄基氯／一氯二乙基铝比例、溶剂、原胶浓度对环化的影响。发现通过控制苄基氯／一氯二乙基铝比,可在高温（１２０℃）、高原胶浓度（２～４％ｗ／ｖ）下进行丁苯橡胶的环化,制得特性粘度较原胶有大幅度降低,可溶性无凝胶的环化丁苯胶。通过对红外光谱、＾１Ｈ－ＮＭＲ谱初步解析,证实了环化反应的发生。     

有机弱碱体系中氢型硅铝MCM-41介孔分子筛的合成及表征

以有机胺为碱源合成出硅铝介孔分子筛MCM-41,并将合成产物的性能与采用传统方法(以氢氧化钠为碱源)合成的产物进行了对比.所合成产物经焙烧脱除有机表面活性剂后即为氢型.XRD和TEM结果表明,所合成的产物骨架具有很高的有序度.固体核磁共振结果显示,铝原子以四配位的形式存在于样品的原粉中.经过高温焙烧,有少量骨架铝脱出骨架,转变成六配位形式.程序升温吡啶吸附红外光谱证明焙烧后产物具有一定的表面酸性.