These are infragravity waves, so called because they are sub-harmonics of the original gravity waves.
这就是亚重力波，之所以这样命名是因为它们是原始重力波的分谐波。
2
The measurement results and analyses shows that the sub-harmonics in, loudspeaker shell are caused by the interaction of vibration modes.
对扬声器的非线性分谐波的测量分析表明，扬声器薄壳分谐波的产生源于扬声器薄壳模态的相互作用。
3
The dynamical model of jump vibration is built, the nonlinear dynamical characteristic of jump vibration is studied and find the sub-harmonics vibration is main characteristic.