在已经向公众推出之后就不要再改变你的URL ，如果你绝对有必要改变你的URL的话，加上重定向——这不那么会引起惊慌。

Don’t change your URLs after they’ve been publicly launched. If you absolutely must change your URLs, add redirects — it’s not that scary.

youdao

本论文主要研究了图的最大亏格的下界问题以及有向图类在可定向曲面上嵌入的亏格分布。

In this paper, the lower bound problems of the maximum genus and the genus distributions of digraphs in orientable surfaces are studied.

youdao