string(266) "get document error：https://zhidao.baidu.com/search?lm=0&rn=10&pn=0&fr=search&dyTabStr=null&word=%E8%AE%BA%E6%96%87%E6%91%98%E8%A6%81%E7%9A%84%E6%A0%BC%E5%BC%8F%E6%80%8E%E4%B9%88%E8%AE%BE%E7%BD%AE => Failed to connect to 101.91.112.32 port 38195: Connection refused"
论文摘要的格式怎么设置
