That's the harmonic series that's on that, and what the valves do is they shorten and lengthen that vibrating column of air very much like the cello string on the fingerboard.

这就是圆号上的泛音列,活瓣的作用是增长或减短,空气柱的高度,很像大提琴指板上的弦

耶鲁公开课 - 聆听音乐课程节选

We'll talk about how your normal valves function inside your heart and how your heart couldn't work in the way that it did if it didn't have valves that were doing a very complex operation many many times a day.

我们会讨论,正常的瓣膜在心脏中如何工作,以及没有这个,每天不停完成很多复杂任务的心脏瓣膜,心脏为什么,就不能正常工作了

耶鲁公开课 - 生物医学工程探索课程节选