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.     

混凝土尿素池的腐蚀及防腐蚀措施

本文对混凝土尿素池的腐蚀原因、规律及影响因素进行了阐述，提出了混凝土尿素池的腐蚀及防腐蚀措施，延长了设备的寿命，保证了尿素生产的正常运转。     

Metallographic sample prepared by ion beam etching

Ion beam etching technique was used to reveal the metallograhpic microstructure and interface morphology of electroplating chromium coating, in particular, whose substrate surface layer was treated in advance by laser quenching. Chemical etchings were also conducted for comparison. The reveal microstructures were observed and analyzed by scanning electron microscopy. The results show that ion beam etching can reveal well the whole microstructures of composite coating-substrate materials.     

Phase transformation behavior in Al-Zn-Cu alloys by hammering

The 5Cu40Zn55Al and 15Cu20Zn65Al alloys were prepared in the AI-Zn-Cu system, There exist the metastable phases ε and θ in the two alloys after homogenization treatment and furnace cooling, respectively. It is shown that the particles are refined from 3 mm to less than 10 μm after hammering the two alloys but there are still metastable phases. This means that the phase constituents of the two alloys have no changes by the deformation, which is different from that by balling. The phase constituents are not changed at room temperature by hammering, which is dependent on the deformation mechanism of hammering.     

高线精轧机平衡缸漏油分析及改进

分析了广州钢铁企业集团公司高线厂精轧机平衡油缸漏油的危害和原因，指出了这种油缸在设计上存在的缺陷，并提出了改进措施，改进后漏油问题得到了解决。     

系统的几种表示方法的探讨与分析

针对“信号与系统分析”、“数字信号处理”课程中对系统的描述与分析过于零散,导致学生学习时不好理解这一现象,分析并归纳了描述系统的数学模型、框图、冲激响应、系统函数及系统频率响应五种方法的基本原理及相应的表达式,并给出了系统的几种表示方法之间的转化关系,对于促进学生在学习过程中对于系统的理解和掌握十分有益.     

用于腺苷检测的基于级联扩增核酸适体电化学传感界面的构建研究

该文报道了一种基于酶级联扩增的电化学核酸适体检测腺苷的新方法。当腺苷存在时,滚环扩增的引物通过E.coli DNA连接酶的作用与通过巯基组装在金电极上的固定探针连接。在pHi29 DNA聚合酶的作用下,滚环扩增反应进行并产生一条与环形探针完全互补的长的单链,然后将大量金纳米粒子标记的核酸探针与滚环扩增的产物杂交。该传感界面电化学行为的结果表明,通过酶级联扩增的方法提高了检测腺苷的阻抗响应灵敏度,且选择性和重现性良好。用于腺苷的检测时,其线性范围为2.0μmol/L~100μmol/L,最低检测浓度为2.0μmol/L,表明该传感界面的设计可作为一种通用方法而有望用于其它目标物的检测。