Effects of Ti addition on microstructures of melt-spun CuCr ribbons

The microstructure and resistivity of melt-spun CuCrTi ribbon were studied.The results reveal that the maximal size of theprimary Cr particles in the microstructures is below 100 nm by 0.65%-3.8%Ti(mole fraction)addition and the resistivity of annealedribbons of 0.65%-1.3%Ti addition can meet the need of the contact materials used by the medium-voltage vacuum interrupters.Bycontrasting the melt-spun microstructures to the annealed microstructures,the primary Cr particles do not grow up quickly in theannealing process.The X-ray diffraction studies reveal that alloying increases the amount of the solute in Cu and Cr phases andresults in the increase of resistivity.By the thermodynamic analysis,adding Ti to CuCr29 alloys increases the critical supercooling ofthe liquid/solid transformation,which makes the critical radius of nucleation decrease and the rate of nucleation increase.As a result,the microstructure of CuCr ribbon can be further refined.     

伺服机构测控系统软件容错技术

介绍了软件容错技术的基本原理和常用方式,同时提出了结合过程数据库和二维思路,针对伺服机构测控系统特点的两种改进的容错方法。     

电气化铁路负荷对电子式电能表计量精度影响的研究

介绍了在Matlab／Simulink环境中构建电气化铁路的负荷模型,同时建立了时分割乘法器（TDM）电能表以及数字式乘法器电能表模型。通过仿真实验比较可知,调制频率越高则时分割乘法器电能表的计量精度越高,采用高阶Kaiser窗类型的滤波器可提高数字式乘法器电能表计量精度。结果表明,虽然电铁负荷含有大量谐波,负序以及冲击性电流,但只要选取合适的电能表参数就能满足计量所需精度。