铬(Ⅵ)与谷胱甘肽作用及其中间态配合物形成的电化学表征

本文采用电化学方法，对谷胱甘肽(GSH)与重铬酸钾的相互作用及其中间态配合物的形成过程进行研究。结果表明：在pH=5.6的HAc-NaAc缓冲溶液中，GSH浓度为Cr(Ⅵ)浓度5倍以上时，Cr(Ⅵ)与GSH作用完全并形成一新的中间态配合物，该中间态配合物于+0.21 V和+0.36 V(vs SCE)处产生一对新的氧化还原峰，UV-Vis的吸收光谱进一步证明了中间态配合物的形成。该配合物不稳定，在一定时间内缓慢分解，其电化学与UV-Vis光谱动力学信息同步。进一步探讨了GSH与Cr(Ⅵ)作用的电极反应机理。当Zn(Ⅱ)存在于该体系时，Zn(Ⅱ)对中间态配合物的生成和分解过程起着双向催化作用。     

Variable Mott-Schottky plots acquisition by potentiodynamic electrochemical impedance spectroscopy

Potentiodynamic electrochemical impedance spectroscopy provides extraction of potential-dependent space charge layer capacitance from potentiodynamic impedance spectra of non-stationary semiconductor–electrolyte interface. The new technique has been applied for acquisition of Mott-Schottky plots of cathodically treated TiO₂ anodic films. Cathodic treatment in 1 M H₂SO₄ increases donor density and flat band potential of TiO₂. Freshly doped films show hysteresis in the space charge layer capacitance in cyclic potential scans. The subsequent cycling eliminates the hysteresis but preserves the greater part of the doping effect. Presented at the 4th Baltic Conference on Electrochemistry, Greifswald, 13–16 March 2005     

Applicability of the Levich Equation for a Two-Phase Solution in the Rotating Disk Electrode System

The mass-transter characteristics of a two-phase system formed by mixing a fixed quantity (20 v/v%) of organic solvent with an aqueous ferricyanide electrolyte solution in an RDE system were studied. The Levich eqution, I₁ = 0.62 nFAC_bD^2/3v^?1/6_ω^1/2, was found to be applicable to the two-phase system with only a minor modification in the angular velocity (ω) at Reynolds numbers between 3–5 × 10⁴. The experimental results indicate that the interfacial tension is the most important variable for the two-phase system. One group of organic solvents with smaller interfacial tension, such as benzene or toluene, needs a modification of the Levich equation by replacing the observed angular velocity (ω_o) with the true angular velocity (ω_t) which was observed to be 1.1 times the observed angular velocity. For the other group with larger interfacial tension, such as n-hexane or cyclohexane, there is no need to modify the observed angular velocity. In other words, the Levich equation may be expressed as I₁ = 0.65 nFAC_bD^2/3v^?1/6ω^1/2 for two-phase solution if the interfacial tension is smaller than 37.0 dyne/cm.     

Mass transport in gas channels of electrochemical cells with a solid-oxide electrolyte: Allowing for the electrode reaction rates in numerical calculations

The concentration fields, Nusselt number distributions along the electrode, and ratios of concentrations of electrochemically active components at the entrance into and exit out of an electrochemical cell are determined by numerical integration of the convective-diffusion equation for a broad range of rate constants of electrode reactions, Peclet numbers, and geometrical parameters of channels. Three regions of parameter values are revealed. At low reaction rates (K _l < 0.5), mass transfer is completely determined by electrode kinetics; at high rates (K _l > 20), it is completely determined by the diffusion in the gas phase; and in the intermediate region of values of K _l it is necessary to allow for both the diffusion processes and the electrode reactions.Translated from Elektrokhimiya, Vol. 41, No. 3, 2005, pp. 317–324.Original Russian Text Copyright © 2005 by Ezin, Somov.     

塑料成型工艺实习CAI课件的开发

针对当前学生实习面临的困难，以Authorware为开发工具，编制了塑料成型工艺实习CAI课件，整个软件图文并茂，图像，动画，解说，音乐相结合，形象地介绍了塑料各种成型工艺的主要原理，生产设备，工艺流程和相关产品，应用本软件学生可以进行模拟实习，该软件激发了学生学习的兴趣，提高了实习质量。     

电化学氟化的新进展

电化学氟化是利用电极反应将氟直接引入有机或无机物的一种重要方法。有机物的电化学氟化方法有两种: 一是Simons于1941年发明的, 用镍作阳极, 在无水氟化氢溶液中, 电解制备全氟化合物的方法。此方法在近年来有不少改进。另一是1970年Rozhkov提出的, 以有机溶剂(如含Et3N.3HF的MeCN)为介质, 在铂阳极上,氧化得到单氟化产物的方法。本文全面地综述了这两种方法, 并着重于最新民发展。     

Application of Nafion／Cobalt Hexacyanoferrate Chemically Modified Electrodes for the Determination of Electroinactive Cations by Ion Chromatography

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Electrochemical detector with a 20 nl volume for micro-columns liquid chromatography

Summary A flow-through two electrode wall-jet cell with a platinum measuring electrode and a cell volume of 20 nl has been designed and evaluated. It has been used to detect phenols by reversed phase liquid chromatography using short micro bore columns. The linear dynamic range between the measured current and the concentration is greater than 10³ (1.5×10^–7–5×10^–4 mol/l) and the minimum analyzable amount was found to be 10 pg for pyrocatechol. A negligible broadening in the detector permits the use of micro columns down to 0.5 mm internal diameter, packed with 5 m particles, without any substantial distortion of eluted zones.Presented at the 14th International Symposium on Chromatography London, September, 1982     

壳聚糖作用下一步法合成具有高电活性的AgCl@聚苯胺核壳结构

在壳聚糖的作用下，采用简单的一步法合成了具有星状结构的氯化银/聚苯胺核壳型复合材料。当壳聚糖的浓度为1%时，所制备的氯化银/聚苯胺复合材料具有高度的分散性，壳层厚度为30～80 nm、核的直径在25～60 nm范围内。通过透射电镜、红外光谱和X-射线衍射对样品的形态和组成进行了表征。循环伏安实验结果表明这种复合材料在中性条件下具有很好的电化学活性。     

New organic metals: Radical cation salts of bis(ethylenedioxo)tetrathiafulvalene with halide mercurate anions

Radical cation salts with halide mercurate anions were obtained by the electrochemical oxidation of bis(ethylenedioxo)tetrathiafulvalene (BEDO-TTF), and their conductivity was studied. The compounds (BEDO-TTF)₄Hg₃X₈ (X = Cl or Br), (BEDO-TTF)₄Hg_3.5I₉, and (BEDO-TTF)₂HgBr₃ possess the conductivity of the metallic type down to helium temperatures.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1167–1170, May, 1996.