如果我站在这里，你们不移动，我移动这些音叉，那么你们会听到不同，频率，这就是我们，所说的多普勒效应。

If you stay where you are and you don't move and I move these tuning forks, you will hear a different frequency and that's what we call Doppler effect.

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这个音叉，产生4000的赫兹，一个很高的频率。

I have here a tuning fork which generates 4,000 Hertz, a very high frequency.

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加工高质量的石英音叉需要解决工艺误差导致的机械耦合误差及频率漂移等问题。

To get high quality quartz tuning forks, mechanical coupling error and frequency excursion by machining errors must be resolved.

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