国产高电流密度离子膜电解槽与引进装置的衔接

尽管国产高电流密度离子膜电解槽与引进装置的设备和生产工艺要求不同,但两套设备可衔接成一体并顺利运行.介绍了两套设备衔接后国产高电流密度离子膜电解槽的运行情况.     

从强制循环到高电流密度自然循环电槽的改造

介绍国内第一套国产高电流密度自然循环离子膜电解槽装置的设计及运行情况。通过改造,装置的生产能力大幅度提高。     

NBH-2.7型自然循环高电流密度复极式离子膜电解装置运行要点

介绍了30万t/a NBH-2.7型自然循环高电流密度复极式离子膜电解装置的运行情况及存在的问题,分析了影响电解装置平稳运行的因素。     

13万t/a高电流密度离子膜电解装置技改

介绍了日本旭化成公司生产的高电流密度电解槽的结构特点,总结了13万t/a高电流密度离子膜装置的运行情况,针对装置在建设过程中出现的6个问题进行探讨并提出了处理措施:①螯合树脂塔树脂流失;②不锈钢材质渗漏;③二次盐水管道渗漏;④脱氯塔陶瓷环破裂;⑤酸泵轴封泄漏;⑥特殊材料供应问题。     

国产高电密离子膜电解槽的应用

介绍了离子膜烧碱装置采用国产化生产的自然循环复极式高电流密度电解槽在生产中的应用情况。     

高电流密度离子膜烧碱装置问题及改进

介绍了高电流密度电解槽的结构特点,总结了装置的运行情况,分析了运行中出现的问题．提出了解决方案并付诸实施,取得了较好效果。     

NBH-2.7型自然循环高电流密度复极式离子膜电解装置开停车方法及运行要点

介绍了NBH-2.7型自然循环高电流密度复极式离子膜电解装置的开车准备、开停车时各工序系统的配合条件、控制方法和技巧,以保证人员和设备的安全以及装置高水平地稳定运行.     

NBH-2.7型自然循环高电流密度复极式离子膜电解装置开停车方法及运行要点

介绍了NBH-2.7型自然循环高电流密度复极式离子膜电解装置的开车准备、开停车时各工序系统的配合条件、控制方法和技巧,以保证人员和设备的安全以及装置高水平地稳定运行.     

高电流密度膜极距电解装置运行经验

介绍湖北兴瑞化工有限公司第1期15万t/a离子膜法烧碱装置运行情况.在高电流密度下通过严格控制各项工艺指标及规范操作,可确保该装置长期稳定运行.     

10万t/a高电流密度离子膜法烧碱装置运行总结

介绍了10万t/a高电流密度离子膜法烧碱装置的二次盐水精制、BITAC-888型电解槽、淡盐水脱氯等工序的装置、工艺控制及运行概况,并针对生产及工艺中存在的问题提出相应的解决办法.     

Response surface analysis to evaluate the influence of deposition parameters on the electrodeposition of Cu–Co alloys in citrate medium

Copper–cobalt alloy coatings were deposited on mild steel substrates using sodium citrate electrolytes at room temperature and under direct current. A set of cathodic polarization curves was plotted by varying the mechanical stirring speed of the solution (0–400 rpm), using a range of current densities during the electrodeposition experiments. Factorial design was used to verify the influence of these deposition parameters on the cathodic efficiency, the copper and cobalt content in the coating, the corrosion current density of the coating/substrate system, and the efficiency of the coating in protecting the substrate. The electroplating experiments showed that, with the studied bath composition, high stirring speed and low current density lead to greater cathodic current efficiency and copper-rich coatings. On the other hand, high current density and low stirring speed yields coatings with high cobalt content and a lower cathodic efficiency. Our results show that the studied parameters affect the corrosion current density and the coating efficiency of the coating/substrate system in opposite ways. The best results were obtained increasing the current density and decreasing the mechanical stirring speed. Additionally, three samples were produced in selected deposition conditions. The coatings morphologies were compact, and their grain sizes seemed to enlarge with increasing stirring speed and decreasing current density.     

4万t/a 32NCH离子膜装置技改情况

简要介绍了旭化成高电流密度电解槽的结构和工艺特点，通过考核及运行表明该型槽在技术上有较明显的提升，可在高电流密度条件下运行。     

PEM fuel cell reaction kinetics in the temperature range of 23-120 °C

The performance of a Nafion 112 based proton exchange membrane (PEM) fuel cell was tested at a temperature range from 23 °C to 120 °C. The fuel cell polarization curves were divided into two different ranges based on current density, namely, <0.4 A/cm² and >0.4 A/cm², respectively. These two ranges were treated separately with respect to electrode kinetics and mass transfer. In the high current density range, a linear increase in membrane electrode assembly (MEA) power density with increasing temperature was observed, indicating the advantages of high temperature operation.Simulation based on electrode reaction kinetic theory, experimental polarization curves, and measured cathodic apparent exchange current densities all gave temperature dependent apparent exchange current densities. Both the calculated partial pressures of O₂ and H₂ gas in the feed streams and the measured electrochemical Pt surface areas (EPSAs) decrease with increasing temperature. They were also used to obtain the intrinsic exchange current densities. A monotonic increase of the intrinsic exchange current densities with increasing temperature in the range of 23-120 °C was observed, suggesting that increasing the temperature does promote intrinsic kinetics of fuel cell reactions.There are two sets of cathode apparent exchange current densities obtained, one set is for the low current density range, and the other is for the high current density range. The different values of cathode current densities in the two current density ranges can be attributed to the different states of the cathode Pt catalyst surface. In the low current density range, the cathode catalyst surface is a Pt/PtO, and in the high current density range, the catalyst surface becomes pure Pt.     

Determination des parametres cinetiques de l'electrodeposition du cuivre a haute densite de courant. Cas des solutions sulfuriques sans inhibiteur

Copper can be deposited at very high current density with an electrolyte flowing at high speed parallel to the electrodes. The cathodic diffusion limiting current density reaches 300 A dm^?2 at a flow speed of 2 ms^?1. The determination of the values of the kinetic constants which characterize copper deposit at high current density requires an adjustment of the electrochemical measuring methods. Copper reduction mechanisms at high current density are different depending on the main type of nucleation, two- or three-dimensional.     

铝电缆镀铜电流密度的快速监测系统设计

在铝电缆表面镀铜工艺中,电流监测系统采用有线传输的方式,监测速度较慢、实时性不高。设计了一种用于铝电缆镀铜电流密度的快速监测系统,阐述了铝电缆电镀铜机理,选用铝片进行实验,利用测量镀层厚度和镀层耐腐蚀性评定方法,进行电流密度对镀层耐蚀性的影响、电流密度与镀层厚度的关系实验,确定电流密度的监测范围。在此基础上,依据系统需求设计总体结构,介绍了主控芯片、电流传感器电路和无线通信芯片,最后进行了软件代码设计。结果表明,所设计的监测系统精度高、监测速度快,可有效利用资源。     

高强高密石墨材料的制备研究现状

讨论了高强高密石墨材料的性能和应用,从原料选择和工艺强化两个方面进行了分析。重点讨论了超细石墨粉、生焦粉、中间相炭微球、"二次焦"、COPNA树脂等原料制备高强高密石墨材料的优点和实际应用中的不足,对现行的高压成型、加压焙烧、加压成型焙烧、多次浸渍再焙烧进行了分析总结。     

Electrochemical synthesis of compositionally modulated FexPd1−x nanowires

Fe_xPd_1−x nanowires were electrodeposited by template-directed growth from ammonium citrate baths by adjusting the current density and metal ions concentration ratio (Fe²⁺:Pd²⁺). A higher current density and ion ratio led to the synthesis of the amorphous Fe-rich FePd nanowires, whereas nanocrystalline Pd-rich FePd nanowires could be obtained by the low ion ratio and current density. To minimize the longitudinal compositional modulation in high aspect ratio pores, pulse current were applied instead of direct current. Also, based on the ability to vary the composition of FePd by adjusting average current density, compositionally modulated FePd nanowires were synthesized at fixed duty cycle.     

木耳碳基硫化钴复合材料的制备及电化学性能研究

以木耳制备的均匀溶液为碳源,加入ZIF-67前驱体,通过水热合成和高温煅烧制备氮硫共掺杂的木耳碳与硫化钴多孔片层复合材料（CoS/NSAC）。实验结果表明,该材料具有大的比表面积和高导电性,电化学性能良好。CoS/NSAC在电流密度为0.5 A/g时比容量达到484.8 F/g,在20 A/g高电流密度下循环5 000次容量保持率为78.8%。用该材料组装的非对称超级电容器具有优异的电化学性能,在0.6 A/g电流密度下比容量为154 F/g。当功率密度为362.3 W/kg时,能量密度为7.4 W·h/kg,经过1 800次循环容量保持率为81.95%。     

Studies of current and potential distributions on lead-acid batteries. II. Discharge of automotive negative plates

The distributions of current density and potential of automotive negative plate were studied by measuring the IR drop in the H₂SO₄ solution between the positive and negative plates. At the beginning of discharge, the distributions of current density, potential and polarization resistance are uniform. In the later stage, high polarization appears at the top and bottom of the negative plate and the current density falls very quickly in these regions. Therefore, high polarization resistance of the active mass increases very quickly at both the top and bottom of the negative plate. It is mainly caused by the passivation of the negative plate which obviously decreases by constant current charge. At low temperature, at the end of 3 C discharge, the highest polarization and the lowest current density appear farthest away from the lug and at the top of the negative plate.     

低温镀铁时电流密度对镀层性能的影响

研究了不同电流密度下所得低温镀铁层的沉积速率、显微硬度和腐蚀速率。结果表明,当电流密度为14A/dm2时镀层可获得最佳的综合性能。电流密度过低时,镀层沉积速率慢,硬度低;电流密度过高时,镀层表面出现针孔,厚度不均。