ENERGY TRANSFER FROM SODIUM N-ALKYL CARBAZOLE SULFONATE TO ZINC TETRAPHENYLPORPHYRIN IN MICELLAR SOLUTIONS

Abstract— In order to study energy transfer to zinc tetraphenylporphyrin (ZnTPP) in micellar solution, a series of surface active agents of sodium N-alkyl carbazole sulfonate, were synthesized. The energy transfer efficiency from the carbazole group near the surface to ZnTPP located in the core of sodium lauryl sulfate (NaLS) micelles was found to be 30%, as observed through the fluorescence of ZnTPP. The critical micelle concentrations (CMC) of the sodium N-alkyl carbazole sulfonate surfactants, determined by scattering, were 2 times 10_-4 M, 3 times 10_-5M and 3 times 10_-6 M, respectively, for alkyl: octyl, dodecyl and hexadecyl. The sensitivity of the CMC of NaLS to the presence of foreign surfactants and solubilizates was also investigated.     

REACTION OF EXCITED CHLOROPHYLL MOLECULES AT ELECTRODES AND IN PHOTOSYNTHESIS*

Abstract— Excited molecules can exchange electrons with suitable electrodes in an electrochemical cell. Excitation energy of molecules can therefore be converted into electrochemical energy. Electrochemical reactions of excited chlorophyll molecules have been investigated with the help of semiconductor electrodes. It is suggested that this type of reaction also occurs during the primary steps of photosynthesis. Consequently, concepts of electrochemical kinetics would have to be applied in order to elucidate chlorophyll-sensitized reactions in photosynthetic membranes. In order to provide evidence for this conclusion, electrochemical kinetics is applied to the calculation of decay of delayed light from photosynthetic membranes, and the result is compared with experimental data from Chlorella pyrenoidosa. The conversion of light into electrochemical energy via photoelectrochemical reactions of organic dyes in an electrochemical cell is demonstrated, and the postulated analogous electrochemical mechanism for photosynthesis is discussed.     

纯炭空气电极的极化机理及数值计算

经验表明,适当选择活性炭材料配方及电极加工工艺,可以得到较好输出性能的纯炭材料空气电极。因此,仔细探讨纯炭材料空气电极的极化机理是很有必要的。本工作根据[1]文中介绍的气体扩散电极极化理论,采用[2]、[3]中的数值方法,对纯炭材料空气电极的极化机理进行讨论。     

带-带和带-平面电极的扩散极限电流

采用保角变换法推导了共平面的带-带电极和带-平面电极的稳态扩散极限电流及带-平面电极的稳态可逆极化曲线的分析表达式.     

金在酸性硫脲溶液中的阳极溶解过程

采用循环伏安法、旋转金盘电极和库仑电解等方法研究了金在酸性硫脲(TU)溶液中的阳极溶解过程。提出了金的阳极溶解机构。认为表面的Au(TU)_(ads)~ 的“化学溶解”步骤是过程的控制步骤。由此解释了旋转金盘电极的极化曲线出现电流峰以及金的溶解速度出现极大的原因。     

PHOTOELECTRONIC EFFECTS IN ORGANIC MATERIALS–II. VARIATION OF PHOTOVOLTAGE WITH pH IN CHLOROPHYLL-QUINONE SOLUTIONS

Abstract— The photovoltaic effect in ethanolic solutions of chlorophyll a with benzoquinone or hydroquinone has been measured as a function of pH. In acidic media, stable, fast-rising photovoltaic signals of positive sign are obtained. In neutral and basic media, less stable, slower rising photovoltaic signals of negative sign are found. The results in acid media are explained in terms of a photochemical interaction between chlorophyll and either the benzoquinone or hydroquinone producing protons which can then act as the electrode active agent. In basic media, negatively charged radical species, such as the benzoquinone radical-anion, are considered to be the most likely electrode-active species.     

四种新型单取代氨基酸四苯基卟啉锌配合物的合成和光谱表征

本文合成了四种新的单取代氨基酸四苯基卟啉锌配合物Zn［Val-TPP］、Zn［Glu-TPP］、Zn［Tyr-TPP］和Zn［Trp-TPP］。通过化学分析和元素分析确定了配合物的组成，研究了它们的紫外、红外、荧光和激光拉曼光谱。     

ZINC TETRAPHENYLPORPHYRIN-SENSITIZED PHOTOREDUCTION OF ANTHRAQUINONESULFONATE IN AQUEOUS MICELLAR SOLUTIONS*

Abstract— Zn-tetraphenylporphyrin (ZnTPP), solubilized in non-ionic surfactant micelles, was found to sensitize photoreductions of some sodium anthraquinonesulfonatesz in the presence of ascorbic acid under anaerobic conditions. The reaction rate was increased by the addition of an anionic surfactant, while retardation was observed with a cationic surfactant. The pH-reaction rate profiles showed maxima located in the order corresponding to pK_a-values for the semiquinone of each anthraquinone-sulfonate. A reaction scheme involving the formation of ZnTPP⁺ at the primary step, followed by back-reduction with ascorbic acid, is proposed. The reaction scheme is in good agreement with the results of flash photolysis. The surfactant micelles are suggested to aid the charge-separation between the ionic species just after the redox reaction involving the photoexcited ZnTPP and anthraquinonesulfonates.     

苯和正己烷在盐甲醉溶液中的活度系数(298 K)

在芳烃或烷烃的甲醇溶液中加入电解质可导致溶性的改变。不同的盐及盐浓度对两者溶度的变化影响不同。有些盐能显著的扩大芳烃或烷经在甲醇中的溶性差异。前人曾提出过利用盐改性的甲醇溶液作芳烃抽提溶剂的设想。本文工作是测定恒温下定组成的苯-甲醇和正己烷-甲醇溶液中苯和正己烷的活度系数随不同盐浓度的变化。所选用的盐是LiCl、NaBr和NH_4Br,它们的甲醇溶液有较大的浓度变化范     

酸性条件下两种马来酸-烯烃交替共聚物诱导细胞色素c的结构转换

在pH=2·9时,细胞色素c保持类天然的结构;和马来酸-烯烃交替共聚物作用后,细胞色素c的α-螺旋结构基本保持不变,但是三级结构被破坏.另一方面,在pH=2·1时,细胞色素c去折叠形成伸展的无规卷曲构象;马来酸-烯烃交替共聚物可以诱导酸变性的细胞色素c从无规卷曲构象转变为α-螺旋结构.在酸性溶液中,由于马来酸-异丁烯交替共聚物和细胞色素c之间更强的相互作用,其对蛋白质结构的影响大于马来酸-1-十四烯交替共聚物.相对于小分子,聚合物可以在低浓度条件下提供有利于蛋白质结构转换的微环境.     

铋膜电极阳极溶出伏安法测定血样中的锌

采用阳极溶出伏安法用玻碳电极同位镀铋膜测定血样中的锌。实验结果表明,在0.20mol/L的支持电解质KSCN(pH=2.80)中于-1.00V下搅拌富集2min后,进行阳极极化扫描,可获一灵敏的阳极溶出峰,利用该方法测定锌的检出限为1.0×10-11mol/L,线性范围为5～25μmol/L。锌标准溶液测定结果的相对标准偏差为3.14%(n=11),加标回收率为95.6%～104.8%。     

THE THEORY OF CURRENT TRANSIENTS AT TUBULAR ELECTRODES IN A FLOWING FLUID

A theoretical equation is developed which describes theresponse of the current transients to a constant potential at tubularelectrodes for a reversible electrode reaction in the flowing fluid.     

酸性介质中H2O2在铂电极上还原过程的电化学振荡行为

通过选择不同酸介质,系统地改变Ｈ２Ｏ２和酸性介质的浓度比例,考察了相应的阴离子对Ｈ２Ｏ２在铂金电极上还原过程的电化学振荡现象的影响,并进行了初步的理论解释     

二丁基次膦酸锌高聚物溶液的平衡粘度

通过对二丁基次膦酸锌聚合物溶液平衡粘度与体系中水含量间关系的研究,证明:高分子溶液的相对粘度随体系中水含量的增加而减少。反之亦然。在室温下可很快地建立起平衡。高分子溶液的平衡粘度值取决于体系的水蒸汽分压。     

酸性介质中1,2-丙二醇在铂电极上吸附和氧化过程的原位FTIR反射光谱研究

应用电化学循环伏安和原位FTIR反射光谱研究1,2-丙二醇在Pt电极上吸附和氧化过程。结果指出1,2-丙二醇的电氧化可按双途径进行。其一经1,2-丙二醇在Pt上解离吸附产物氧化至CO_2。但在较低电位下这些解离吸附产物(红外检测为CO_(ad)、?C=CH_2]_(ad)等)累积吸附于电极上,毒化Pt表面抑制其它反应。当电位大于0.3V后它们一经生成即氧化脱附,从而使1,2-丙二醇得以在未毒化Pt表面经反应中间体氧化至CO_2。在实验条件下,原位FTIR反射光谱检测到的反应中间体可能有HOC-CHOHCH_3(或CH_2OHCOCH_3)和HOOC-COCH_3(或HOOC-CHOHCH_3)等物种。     

气相色谱法测定甲苯和正癸烷在聚苯乙烯溶液中无限稀时的活度系数

用气相色谱法测定了130°—200℃之间甲苯和正癸烷在四个分子量不同的聚苯乙烯样品的溶液中无限稀时的活度系数和Flory-Huggins相互作用参量。对于φCH_3-PSt系统,得到: In Υ(O)= -1.0505lnZ+1.1031,(130—201℃)对于nC_10~0-PSt系统,得到: ln Υ(O)= -0.9761lnZ+1.9631,(130—201℃)表明两系统均接近于无热溶液。对于170—201℃的φCH_3-PSt系统,得到: 1+X=4.857Z~(-1)+0.7560据此对气相色谱法测定高聚物分子量的可能性进行了讨论。     

镀锌废酸中铁、锌含量的测定方法

镀锌废酸液具有高铁、高酸、低锌的特性.镀锌废酸液中铁约是锌的10倍,主要以Fe2+形式存在,用H2O2将Fe2+转化为Fe3+,转换率达到100%,且反应体系中不产生新的测定干扰元素.采用氟化钠掩蔽镀锌废酸液中高浓度的Fe3+,解决了Fe3+对EDTA络合滴定测锌的强烈干扰,方法的回收率达到97%以上.用H2O2将镀锌废酸液中高含量的Fe2+全部转换为Fe3+.用碘量法分别测定总铁、Fe3+,其回收率分别为99%、98%以上,通过计算得到Fe2+在镀锌废酸液中的含量.     

火焰原子吸收光谱法测定重晶石中锌铜铁

提出了火焰原子吸收光谱法测定重晶石中锌、铜和铁的方法 ,相对标准偏差为 1 .7%～7.3% ,加标回收率在 95.2 %～ 1 0 3.2 %之间。特征浓度锌为 0 .0 1 0 μg·ml-1/1 % ,铜为 0 .0 35μg·ml-1/1 % ,铁为 0 .0 67μg· ml-1/1 %。方法简便、准确、可靠。     

甲基苯基次膦酸与锌盐的水溶液配位聚合及聚合物水溶液的电导行为

<正> 次膦酸金属配位聚合物具有良好的耐高温性能。但象许多其它无机聚合物一样,某些次膦酸金属配位聚合物不耐水解,如有些聚合物与水长期接触后,即转化为粉末,不复溶于原有机溶剂中。Block等曾简短报导过二甲基次膦酸锌的水溶液测不出特性粘数,所以,为制备这类聚合物,文献上都采用无水有机溶剂作为反应介质的合成方法,