冷喷涂技术的应用现状及展望

简要介绍了冷喷涂技术的原理与特点,冷喷涂工艺参数、粒子沉积行为与喷涂后涂层的性能等研究现状,并对冷喷涂技术的应用前景进行了展望。     

稀土永磁径向环取向磁场的研究

通过采用直流磁场叠加脉冲磁场的方法,研究取向磁场强度、分布形态等对稀土永磁径向环性能的影响,为径向环的生产提供了一定的依据。     

添加镁离子对碳酸钙结晶形貌的影响

考察了溶液结晶法制备碳酸钙过程中添加镁离子的作用,得到2种形貌截然不同的球状碳酸钙.结晶体系中[Ca2+]∶[Mg2+]的大小对碳酸钙的晶相结构及形貌有显著影响其值在1.33～2.67的范围是碳酸钙形貌的过渡区,当>2.67时晶体呈现特殊的聚集台阶群生长现象,形成粗面类球形方解石聚晶体;而在<1.33时得到表面相对光滑的微球.合成条件中[Ca2+]∶[CO2-3]的大小对碳酸钙形貌的影响不明显.     

基于ASP和数据库技术的文件存取处理技术

详细分析了muhipart／form-data型数据流的格式，给出了分离muhipart／form-data型数据流的算法，对上传文件的数据存储、显示进行了讨论，认为利用数据库技术进行存储更优于文件直接写盘方式，给出了基于ASP和数据库技术上传文件的数据流分离、存储和显示的实现方法。     

单兵定位导航系统数据融合方法研究

研究单兵定位导航系统的GPS导航信息与航位推算信息的数据融合方法,采用卡尔曼滤波技术设计了联合卡尔曼滤波器,给出联合滤波算法并仿真.该滤波器具有较高的系统容错性能,数据计算量小,但局部估计精度为常规水平.     

加速我国电器制造业数字化的策略

介绍了制造技术发展趋势以及如何用现代制造技术改造传统的电器制造业,其重点是企业信息化和制造工艺现代化.分析了目前信息化存在的重要问题,提出了企业制造业实现信息化的具体内容和步骤,包括实现数字化设计、生产、装备和管理技术的开发和应用.     

自适应算法在有载调压变压器差动保护中的应用

首先分析了有载调压变压器由于变压器抽头的改变而引出的问题,在此基础上提出一种自适应算法,可在线消除由于CT不匹配引起不平衡电流的影响。另外,对于励磁涌流的判别,提出一种基于电压开关量的自适应算法。仿真实例证明该文算法对CT电流校正、励磁涌流鉴别是有效的,在保证动作时间的同时增加了动作的可靠性。     

Processing technique and sliding friction and wear behavior of TiB2／ZA27 composite

In-situ TiB2 particles reinforced ZA27 composite was prepared by the stir-casting technique and a twostep method. TiB2/Al composite was produced by incorporating K2 TiF6, KBF4 salts and other agents into Al melt. As a master alloy, TiB2/Al composite was used to manufacture TiB2/ZA27 composite, which results in the generation of well-distributed reinforcing TiB2 phase. The hardness, friction and wear behavior of TiB2/ZA27 composite were investigated. The results show that the hardness of the composite is enhanced with increasing the content of TiB2 particles, the incorporation of TiB2 reduces the wear rate of TiB2/ZA27 composite and improves the friction property under lubricated and dry sliding friction conditions. The worn track width of ZA27 alloy is 1.6 and 2.5 times as long as that of 2.1%TiB2/ZA27 composite at 150 N and 700 N load under lubricated conditions, which indicates that TiB2/ZA27 composite possesses higher bearing ability.     

Temperature distribution for controlled-dwell extrusion of γ-TiAl

Ti-47Al-2Cr-2Nb-0.15B alloy (atom fraction) was extruded at temperatures(Ta) of 1250 and 1330℃,respectively. The method of adding a thermal insulating layer was used to overcome the problem associated with the flow stress mismatch between the can and the billet during extrusion. Effects of two kinds of insulations, ZrO2 powders and silica fibers, on the quality of extrude bar along the radial direction were studied, and the process parameters were optimized by combining with finite element method (FEM). Tensile properties of the extruded alloy at room and elevated temperature were tested. The results show that the silica fibers has better thermal insulating property than ZrO2 powders. The temperature distribution in radial is more homogeneous using silica fibers. The alloy has a good balance of yield strength and room temperature ductility and the values are 680 MPa and 3.5%, respectively.     

并联补偿装置运行中的异常现象及对策

就并联补偿装置运行中较易发生的异常现象和合闸涌流引起的过电压、并联补偿装置切除时开关重燃引起的过电压以及系统高次谐波和投入空载变压器对并联补偿装置的影响和危害,进行了详细的分析,提出了有针对性的解决办法.