铜电极表面硝酸盐电化学还原机理研究

目前地表水受到严重氮污染,其中以离子态硝酸盐为主。实验利用线性扫描伏安法与恒电位电解法,研究了铜电极表面硝酸盐电化学还原产物与反应机理。结果表明,硝酸盐的还原产物取决于外加电位。铜电极上硝酸盐的吸附从-0.6 V(以汞/氧化汞电极为参比)开始,-0.8~-1.0 V之间硝酸盐还原为亚硝酸盐,该反应为整个硝酸盐还原过程的速控步骤;理想产物氮气主要在-1.0~-1.2 V之间生成;-1.2~-1.4 V之间主要还原产物为氨氮。随着电势降低,反应速率增大,对副产物氨氮的选择性也升高。     

GB/T 21529-2008《塑料薄膜和薄片水蒸气透过率的测定——电解传感器法》标准介绍

本文介绍了GB/T21529-2008《塑料薄膜和薄片水蒸气透过率的测定——电解传感器法》的实施进度。并且将该标准与ISO15106-3:2003、GB/T1037-1988进行了详细的条款对比。     

Simulation of the C5 Aliphatic Petroleum Resins Production Process

Abstract

Petroleum resins are used widely in many industries. They are solvable in most of aromatic and aliphatic solvents. There are different grades of petroleum resins from dark and viscose liquids to bright and hard ones. They are used mostly in the adherent industry as binder. In this article the production process of aliphatic petroleum resin is simulated based on the process described in Stanford Research Institute International. Regarding the lack of kinetic information about the dimerization process of cylcopentadiene as well as the polymerization process, suitable kinetic rate equations are derived from experimental tests done by Shakeri (2002) Shakeri, M. 2002. Experimental and theoretical study of the effective parameters on petroleum resins cationic polymerization kinetics Tehran: Amirkabir University of Technology. Stanford Research Institute. M.Sc. Thesis [Google Scholar] and used in the simulation. Simulation outputs are in good accordance with the given data in SRI.     

6kA新型铈电解槽内电磁场的数值模拟

针对6kA新型铈电解槽结构,建立数学模型与物理模型,根据Maxwell电磁场方程和Biot-Savart定律,运用COMSOL模拟软件进行电场和磁场的有限元模拟,考察电解槽内电场和磁场的分布情况。研究表明,阴阳极之间是电解的主要区域,也是电流产生的磁场的主要分布区域,并且磁场分布在圆周方向上,径向和轴向的分量为零。     

Synthesis of tetramethyl ammonium hydroxide by cell diaphragm electrolytic method

Under the conditions of tetramethyl ammonia chloride (TMAC) used as starting material, Ti-based Dimensionally Stable Anode (DSA), stainless steel used as cathode and Nafion 900 cation membrane as cell diaphragm, this paper studies the synthesis of tetramethyl ammonium hydroxide (TMAH) by cell diaphragm electrolytic method, examining not only the effects of current density, concentration of starting material and cell temperature, on the product purity and current efficiency, but also the effects of electrolyte circulation rate on the service life of Ti-based DSA.The experiment puts forward an optimum processing condition, and experimental findings show that preparing TMAH by using this technique can obtain a current efficiency 74.7 , and get product with a purity greater than 99.9,.     

小型间歇式次氯酸钠发生器的设计参数研究

为提高小型间歇式次氯酸钠发生器的适用性和可靠性,综合考虑农村小型供水工程特点,结合两端式板式电极,采用单因子试验方法开展电极结构、阴极材质、电极安装高度、盐水浓度、配盐水质、盐水体积、电流密度等设计参数的试验研究。试验结果表明: 小型间歇式次氯酸钠发生器的最佳设计参数为: 电极左右间距 6 cm,阴、阳极采用相同涂层,电极板间距 5 mm,电极板中心距电解槽底部 20 cm,盐水浓度3% ,盐水体积30 L,电流密度480 ～ 640 A /m2,电解时间300 ～ 360 min,有效氯浓度 8. 50 ～ 8. 80 g /L,有效氯产量 255 ～ 264 g,运行成本 7. 16 ～ 7. 20 元/ kg。此外,亦可结合实际供水工程规模、消毒剂需求量、电解时间等多个因素,选择适宜的电解参数。试验结果为下一步设备定型和实际应用奠定了良好基础。     

异形滚柱的在线电解修型成型磨削工艺试验研究

介绍了一种用于汽车和摩托车上先进超越离合器异形滚柱的在线电解成型(ELID)磨削加工工艺试验及相关设备与装置,主要包括成型磨削的工艺实施方案,在平面磨床上实现成型磨削的工装设计及在线电解砂轮修型的装置设计与布局等问题。理论上分析了ELID成型磨削在加工中能按照理想的成型曲线自动修正砂轮母线的形状,从而达到很高的形状精度和较低的表面粗糙度。总结了影响加工质量和效率的因素和规律;同原来的成型拉削相比,采用成型磨削具有效率、质量与稳定性、工具成本和管理等方面的诸多优势。     

非开挖斜井导航埋设接地极降低接地电阻研究

以工程实际为例,介绍了非开挖斜井埋设电解接地极技术在变电站接地网处理中的有效运用,为高电阻率地区变电站接地网的处理提供了值得借鉴的模式.     

铝电解电容器等效串联电阻的分析及控制

文章分析了铝电解电容器等效串联电阻对产品性能的影响,讨论了等效串联电阻的构成及其影响因素,阐述了铝电解电容器生产中控制等效串联电阻的对策,推出了一种改进的铆接工艺,能够有效降低、稳定电极箔与引线间的铆接接触电阻。