Corrosion protection of iron by polypyrrole modified by copper using the cementation process

Polypyrrole (PPy) coatings have been deposited on iron from aqueous oxalic acid solution at different current densities. The polymer deposit obtained at a current density of 2 mA cm⁻² yields strongly adherent and smooth PPy layers. The modification of the film by incorporation of copper microparticles using the cementation process was applied. The resulting PPy/Cu film electrodes were characterized by scanning electron microscopy and EDX analysis. The protective performance against corrosion of these films is evaluated by using open circuit potential monitoring in highly corrosive solution (3% NaCl + HCl, pH 1). The results obtained were promising in the protection against corrosion.     

Effect of surface modification of metal hydride electrode on performance of MH/Ni batteries

A novel method was applied to the surface modification of the metal hydride(MH)electrode of MH/Ni batteries.Both sides of the electrode were plated with a thin silver film about 0.1μm thick using vacuum evaporation plating technology,and the effect of the electrode on the performance of MH/Ni batteries was examined.It is found that the surface modification can enhance the electrode conductivity and decrease the battery ohimic resistance.After surface modification,the discharge capacity at 5C(7.5A)is increased by 212 mA.h and the discharge voltage is increased by 0.11 V,the resistance of the batteries is also decreased by 32%.The batteries with modified electrode exhibit satisfactory durability.The remaining capacity of the modified batteries is 89%of the initial capacity even after 500 cycles.The inner pressure of the batteries during overcharging is lowered and the charging efficiency of the batteries is improved.     

TiB2/Cu复合材料用于电火花加工电极的可行性探讨

从分析电火花加工对电极材料的基本要求入手，结合TiB2／Cu复合材料在目前制备工艺条件下所获得的电学、力学性能等特性，采用对比研究的方法，探讨将其作为电火花加工电极材料的可行性。     

Effects of pH value of reaction solution on structure and electrochemical performance of calcium-containing active material of secondary zinc electrodes

The calcium-containing active material of secondary alkaline zinc electrodes was prepared by a chemical coprecipitation method and characterized by scanning electron microscopy(SEM) and X-ray diffractometry(XRD).Their electrochemical performance was tested by the Galvanstatic charge-discharge method. The experimental results show that the sample synthesized at pH: 11. 15 has a typical calcium zincate crystal. The zinc electrode using this sample as active material shows higher discharge capacity, more negative discharge plateau potential and longer cycle lifetime.     

高频群脉冲电解加工控制系统研究

介绍了高频群脉冲电解加工的控制系统，其核心部件由PMAC运动控制器和PCL-818HD多功能数据采集板构成，主要功能包括控制工具阴极进给、极间加工间隙及短路保护等。实验表明，该控制系统能保证加工的高精度、稳定性及可靠性。     

离子注入铅的铝电极腐蚀的交流阻抗研究

通过测量25℃时1.28g/ml硫酸溶液中铝电极和离子注入铅的铝电极的交流阻抗谱,研究了铅离子注入量对铝电极的腐蚀速率的影响。在此基础上,测量了离子注入铅的铝电极和铝电极在同种介质中的Tafel曲线,辅助交流阻抗法研究电极的腐蚀行为。以此总结出离子注入铅的铝电极的耐腐蚀性能,并探讨了它的腐蚀机理。     

用丝束电极研究SO_4~(2-)对纯铝缝隙腐蚀的影响

采用动电位极化和丝束电极技术测量了纯铝在2mol/L NaCl和2mol/L NaCl 0.8mol/L Na2SO4溶液中的极化曲线、缝隙内外的自腐蚀电位和电化学阻抗分布,研究了SO42-对铝缝隙腐蚀的影响。结果表明,在NaCl溶液中,缝隙内的铝为阳极、缝隙外为阴极;随浸泡时间增加,腐蚀不均匀性增加。加入Na2SO4后,减小了缝隙内外腐蚀电位差,显著降低了铝的腐蚀速度。Na2SO4是中性溶液中铝的吸附型缓蚀剂,延缓了缝隙腐蚀的发生。     

Performance of positive and negative electrodes in amorphous manganese oxide supercapacitor

Using potassium permanganate and acetic manganese as the reactants, amorphous manganese oxide was prepared with mechanochemical method. XRD was used for microstructure characterization, while cyclic voltammetry and constant current charge-discharge were used for electrochemical performance testing. The positive electrode （PE） and negative electrode （NE） were investigated respectively in amorphous manganese oxide supercapacitor, aiming to find their different performances in charging-discharging. The results show that the crystalline structure is destroyed in both the PE and NE material during charge-discharge process. Thereinto, the NE suffers a bit more seriously. When cycling, the PE potential scope diminishes while the NE potential scope enlarges. The increased inner resistance makes the NE curves almost bended to be a right angle, but not the PE curves. The cell＇s equivalent series resistance （ESR） is more dependent on the NE, and the capacitance is mainly determined by the rapid descent of the NE potential range. The capacitances of the NE are highly rate-dependent, decreasing from 121.3 to 53.1 F/g, by 56.2%, over the range of 5-25 mV/s. However, the PE appears to be weakly dependent and its capacitance is only dropped by 22.1%.     

微型点焊时电极表面熔敷TiC涂层对电极失效的影响

研究了表面处理对微型点焊镀镍钢板和镍板时电极失效的影响.结果表明:微型点焊镀镍钢板和镍板时电极的失效主要是电极头部的塑性变形以及电极和镀镍板之间局部焊接的断裂发生在电极表面而导致的电极磨损;表面涂敷TiC的CuCrZr电极的寿命(1 200点)是CuCrZr电极寿命(600点)的两倍,表面处理能提高电极寿命的主要原因是表面涂敷的TiC颗粒能阻碍电极和镀镍板之间的局部焊接,以及减小电极表面的塑性变形.     

高压汽轮机汽缸调门座裂纹的挖补处理

崇明电力公司16号汽轮机调门座发生裂纹后，通过对该阀门座合金钢材料焊接性、再热裂纹敏感性的理论分析，为现场焊补工艺提供了预热湿度和焊后热处理的工艺依据。论文叙述了在现场施焊工艺中选择了与母材化学成分基本相同的超低氢电焊条和其它严格的焊接的工艺措施，确保了优质焊接质量。实践证明，采用此种焊接工艺方法是现实和可行的。