string(257) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E7%94%9F%E4%BA%A7%E8%83%BD%E5%8A%9B%E6%8C%87%E6%95%B0%E4%B8%BA1%E7%9A%84%E6%84%8F%E6%80%9D => Failed to connect to 14.18.117.71 port 38041: Connection refused"
生产能力指数为1的意思
