string(240) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E6%B0%B8%E7%A3%81%E7%94%B5%E6%9C%BA%E4%BB%80%E4%B9%88%E5%8E%9F%E7%90%86 => Failed to connect to 125.88.227.171 port 38062: Connection refused"
永磁电机什么原理
