这些被称为重子声学振荡的东西为测量随时间变化的宇宙的膨胀速度和对暗能量的值施加限制提供另一尺码。
These so-called baryon acoustic oscillations offer another yardstick for measuring the expansion rate of the universe over time and putting limits on the value of dark energy.
介绍了声学测温的基本原理，推导了声波传播速度与介质温度的关系式，阐述了声学测温的巨大优势和存在问题。
The main principle is introduced, and the relationship between speed of sonic wave and media temperature is deduced. The great merits and existing questions of acoustic pyrometry are shown.
回声测深仪是用来测量水深的一种声学测量设备，其以水中超声波的传播速度为确定条件，利用发射波与反射回波时间差来测量水深。
Echo Sounder is a kind of acoustic measuring depth equipment, which can measure depth with the time between transmitted wave and echo on condition in which the speed of ultrasonic is fixed.
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