wave trough

基本解释

Besides, the propagation speed will be different part of the wave, this leads to deformation of a wave trough or wedge in the course of motion.
而且移行速度在波槽或脊的各部分不同，将引起槽线或脊线在移行过程中出现自东北向西南歪斜的变形。
The results indicate that the disintegration of the jet column is caused by the surface waves propagating along the jet body. The jet breaks up at the wave trough.
结果表明：沿射流柱表面传播的表面波是引起射流柱破碎的主要因素，破碎点位于表面波的波谷。
In supersonic flow, results indicate that the disintegration of the jet column is caused by the surface waves induced by aerodynamic forces and the breakup point is at the wave trough.
结果表明：在超声速气流中，射流柱破碎是由迎风面的表面波引起的，破碎点位于表面波的波谷。

But Google too had been through a trough just before, after the failures of Wave and Buzz.
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