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，將引起槽線或脊線在移行過程中出現自東北曏西南歪斜的變形。
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.
結果表明：沿射流柱表麪傳播的表麪波是引起射流柱破碎的主要因素，破碎點位於表麪波的波穀。
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.
結果表明：在超聲速氣流中，射流柱破碎是由迎風麪的表麪波引起的，破碎點位於表麪波的波穀。

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