查询词典 electrolysis

"Industrial methods of caustic-soda production developed in the 18th century and 19th century (the Solvay, or ammonia-soda, process) have been largely displace d by electrolysis."

18和19世纪时发展生产苛性钠的工业方法现已大部分被电解法所取代。

"Industrial methods of caustic -soda production developed in the 18th century and 19th century (the Solvay, or ammonia-soda, process) have been largely displaced by electrolysis."

18和19世纪时发展生产苛性钠的工业方法现已大部分被电解法所取代。

In order to disclosure the reason why the electrocatalysis activeness and selectivity droped after being used several hundred hours continuously, the x-ray diffraction, scanning electron microscopy and energy dispersive spectroscope have been used to characterize the surface condition variations of Monel metal. The results indicated: Monel metal belongs to the Cu-Ni alloy around the electrolysis experiment.And after being used for 600hr, the surface layer element composition and geometry distribution of the alloy changed, namely in the alloy the Cu element /which superficial free enthalpy was smaller,"concentrated" to the alloy surface,and formed one kind of marble structure microcrystallite.Thus the electrode surface becamed rough a

为了揭示蒙乃尔合金阴极在连续使用数百个小时后电催化活性剂选择性下降的原因，采用X射线衍射仪、电子扫描电镜和电子能谱分析仪对电解实验所用的蒙乃尔阴极材料在电解实验前后的表面状态进行了表征，结果表明：所使用的蒙乃尔合金阴极材料在电解实验前后均属于Cu-Ni合金，使用600hr后，由于表面层元素组成和几何排布发生了变化，即合金中表面自由焓较小的Cu元素向合金表面&富集&，形成一种大理石结构的微晶，表面粗糙、不均一，这是造成其对硝基苯电还原的催化活性及选择性随着使用时间延长而逐渐下降的主要原因，同时也为此类电极的修饰改进提供了方向。

The main research work of this dissertation is as follows: Based on the chemical reaction engineering theory and the nitrobenzene electroreduction mechanism, the plate and frame electrolyzer was designed and applied to the process of electroreduction nitrobenzene to p-aminophenol. This dissertation measured the residence time distribution data of the electrolyzer by means of the pulse response method and studied the rule of flow pattern along with the current capacity change. Under different conditions ,this dissertation studied the cyclic voltammetry properties of nitrobenzene on different electrodes by means of the dynamic cyclic voltammetry method and the electrode materials applied to the NB electroreduction have been selected primarily.Baseed on the results of cyclic voltammetry tests, this dissertation used p-electrode systems to measure the steady-state- polarization curves of nitrobenzene on different electrodes in H-type diaphragm cell, and obtained each primary factor s influence rule and the exchange current density value of each electrode.And then on the basis of the conclusions of fundamental researchs upword, the effects of influence factors on the the yield of p-aminophenol and the current efficiency,such as electrode material, current density, quantity of electricity circulated, nitrobenzene concentration . sulpuric acid concentration and so on, have been studied in detail in the systems of hign temperature , strong acidity and oxygen-poorthrough a series of electrolysis experiments in this paper.After all using Pb as anode Monel metal as cathode Dupont Nafion 417 cation-exchange membrane as membrane, this dissertation obtained the optimum technological condition: reaction temperature about 85C, current density 500A m-2, sulphuric acid concentration 20%wt.

论文的主要研究工作为：运用化学反应工程理论，结合硝基苯的电还原机理，设计出用于硝基苯直接电还原合成对氨基苯酚实验的板框式电解槽，并利用脉冲响应法测定了该板框式电解槽的停留时间分布数据，研究了流型随流量变化的规律；通过动态循环伏安法研究了硝基苯在不同电极上、不同条件下的循环伏安特性，初步评选出了用于硝基苯电还原的电极材料；结合循环伏安的测定结果，在H型隔膜电解槽中采用三电极体系测定了硝基苯在不同电极上、不同条件下的稳态极化曲线，得到了各主要因素的影响规律及硝基苯在各个电极上电还原的交换电流密度数值；在基础研究结论指导下，采用板框式电解槽，在高温、强酸、贫氧系统中，进行了一系列的电解实验，分别考察了电极材料、电流密度、通电量、硝基苯浓度、硫酸浓度等因素对收率及电流效率的影响，最终选择以蒙乃尔合金电极作为阴极、铅合金为阳极、Dupont Nofion 417阳离子交换膜为隔膜，得到由硝基苯直接电还原制对氨基苯酚的最佳电解工艺条件：反应温度85℃，电流密度500A·m~(-2)，硫酸浓度20％wt。

I am accused of being overreligious," she said in her quiet, frank manner,"but that does not prevent me thinking the children very cruel who obstinately commit such suicide.""

客人们在卡罗利娜·埃凯家里，举止就文雅一些，因为卡罗利娜的母亲治家很严厉。

Designed by French fashion house Herm è s, this elegant uniform was manufactured in our home, Hong Kong, and was the first without a hat.

由著名品牌 Herm è s 设计，这件高贵的制服是香港本土制造，是我们第一套不配帽子的制服。