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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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