A state where it's closed, so imagine a channel with a lid on top of it; when it's closed nothing can go through the channel, when it's open then things can go through.

一种是闭合状态,想想一个有盖子的通道吧,当盖子合上的时候任何东西都不能通过,而打开时就畅通无阻

耶鲁公开课 - 生物医学工程探索课程节选

If you go to the very top of Kearny, there's Coit Tower up on the hill there. That's really cool.

如果你走到干尼街的尽头，就会看到山顶上的科伊特塔。那里很棒。

旧金山的热点 - SpeakingMax英语口语达人

s And if we go ahead and superimpose the 3 s on top of the 3 p, you can see that the 3 s actually has some bit of probability density that gets even closer to the nucleus than the 3 p did.

如果我们继续将,重叠到3p上面，你们会看到3s事实上,有一点概率密度,距离原子核更近,比3p轨道。

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