奈奎斯特准则提供了一种图形方法来确定闭环系统的稳定性。

"I think the mind is the most important thing in any sport. If you can control your mind, you can control the situation."

小说是一种印象，不是一种论证；它是生活的一种印象。

The solution of a problem appears suddenly and is not approached by a gradual, step-by-step procedure.

永远不要停止相信自己。