This paper presents a study of the reflection of sound pulse from porous material in the ease that the impulse sound source and receiver are located on a line perpendicular to the surface of material.

本文提出当脉冲声源和接收点在同一条垂直于材料表面的直线上时，声脉冲从多孔材料反射的研究。

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Since the speed of light is about a million times as great as that of sound waves, the reflection of light waves may very well be applied in detecting a target and its distance.

光速大约为声速的100万倍，因此光波的反射现象可以有效地用来探测目标物及其距离。

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By integrating historic film material with contemporary images this filmic poem continues the timeless reflection of East and West in images, words and sound.

通过把历史电影素材和当代图像结合起来，这部电影诗歌继续用图像、文字和声音进行关于东西方的永恒思考。

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The 44-page work is a no-nonsense member of the well-known Dummies series that purports to educate the nation's public pension officials on the ABCs of sound financial management--a task that the author himself concedes is a chilling reflection of the state of public pension fund management.

FORBES: Magazine Article