基于Matlab的电力系统短路暂态分析

以往电力系统的仿真计算往往采用结构化的C语言或Fortran语言来进行。C语言和Fortran语言在科学计算中发挥了重要作用 ,而Matlab作为一种新型的高性能的语言 ,它和传统的程序设计语言相比具有强大的数学运算功能和绘图功能。文中主要介绍了如何用Matlab来进行短路暂态分析 ,并通过一个发电机出口端发生三相短路的算例来说明它的有效性     

Characterization of sputtered ZnO films under different sputter-etching time of substrate

Polycrystalline ZnO films are prepared using radio frequency magnetron sputtering on glass substrates which are sputteretched for different time. Both the size of ZnO grains and the root-mean-square (RMS) roughness decrease, as the sputteretching time of the substrate increases. More Zn atoms are bound to O atoms in the films, and the defect concentration is decreased with increasing sputter-etching time of substrate. Meanwhile, the crystallinity and c-axis orientation are improved at longer sputter-etching time of the substrate. The Raman peaks at 99 cm⁻¹, 438 cm⁻¹ and 589 cm⁻¹ are identified as E₂(low), E₂(high) and E₁(LO) modes, respectively, and the position of E₁(LO) peak blue shifts at longer sputter-etching time. The transmittances of the films, which are deposited on the substrate and etched for 10 min and 20 min, are higher in the visible region than that of the films deposited under longer sputter-etching time of 30 min. The bandgap increases from 3.23 eV to 3.27 eV with the increase of the sputter-etching time of substrate.