The county of Yishui (literally water from the Yi) gets its name from its geographical position, which is on the upper reaches of the Yi River. Through efforts
人们在使用手机时,希望手机对人体的辐射尽可能的小。因此,在手机天线优化设计中,安全性是一项重要考虑因素。本文利用时域有限差分法对用于个人通信手机的缝耦合微带天线与单极
针对线性信道下四次方环,二相COSTAS环,MAP环应用于UQPSK系统的局限性,提出了一种易于实现的非线性信道下UQPSK系统的载波恢复环-基带处理环,并分析了其性能。通过计算机模拟证明,基带处理环用于提取非
为实现主运输斜巷绞车房机械化换人、自动化减人的目标,决定应用操车自动化控制系统,即在主运输斜巷轨道上车场安装了综合集控操作台、自动化推车机,将绞车控制、推车机控制、车
The Shanghai Leather Corporation has a production and export history of 40 years. It possesses 32 factories, 17 joint ventures, a research institute of the leat
The magnetic head products, developed by the Kaifa Scientific Co. Ltd. have been sold to Japan, Taiwan, Southeast Asia, Europe and America. Since its founding f
The China Yangtze Group Corp. was founded in 1980. Now it has developed into a large state-owned consortium, with its business scope covering electrical applian