低于一定的临界值的话，它们将不足以克服表面气体的对流混合，因而太阳黑子将完全消失。

Below a certain threshold, they will not be strong enough to overcome the convective mixing of the gas at the surface, and spots will disappear altogether.

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介绍和讨论利用粗颗粒钛粉末净化普通氮气及其在钛表面气体氮化工艺中的应用。

This article introduces and discusses the purification of ordinary nitrogen by coarse titanium powder and its application in gas nitridation technology of titanium surface.

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并指出，随着研究工作的深入，该项技术还可望用于高马赫数飞行体表面气体流动控制、火箭发动机推力方向控制等。

Along with the deep development of study, the microjet technology will be possibly applied to control the aerodynamic flow of the high speed aircraft surface and the thrust vector of rocket engine.

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So, one difference between photoelectron spectroscopy and, for example, the photoelectric effect is that in this case, we're not just looking at one energy level, which is what we were looking at from the surface of a metal, now we're talking about this gaseous atom.

光电子能谱与光电效应的不同点在于，以这种情况为例，我们不只关心一个能级，就像原来在金属表面那样，现在我们研究的是气体原子，所以，我们可以从原子中。

麻省理工公开课 - 化学原理课程节选