| 1. | Acoustics . attenuation of sound in air
声学.空气中声音的衰减 |
| 2. | Acoustics - attenuation of sound during propagation outdoors - part 2 : general method of calculation
声学户外声传播的衰减第2部分:一般计算方法 |
| 3. | Acoustics - attenuation of sound during propagation outdoors - part 2 : general method of calculation iso 9613 - 2 : 1996
声学.室外传播过程中声的衰减.第2部分:一般计算方法 |
| 4. | Acoustics - attenuation of sound during propagation outdoors - part 1 : calculation of the absorption of sound by the atmosphere
声学户外声传播衰减第1部分:大气声吸收的计算 |
| 5. | Acoustics - attenuation of sound during propagation outdoors - part 1 : calculation of the absorption of sound by the atmosphere
声学.声音室外传播的衰减.第1部分:大气对声音吸收的计算 |
| 6. | We consider there are two kinds of mechanism causing the attenuation of sound in grain . one kind of mechanism regards the grain as quasi - porous media . it was the viscous resistance and heat conduction in the narrow passageways between the grain kernels that convert the sound energy into heat energy and lose it
首次建立了准多孔介质的概念，可将堆积的粮食看作准多孔介质(颗粒介质) ，透入粮食内部的声波在孔隙中传播时，由于粘滞性和导热性的效应，把声能逐渐变成热能耗散。 |
| 7. | Experimental studies on the influences of the deflected plates upon the oscillations were focused on the attenuations of sound pressures of the oscillations with the bent plates of various angles and lengths . the results show that the bent plates with angels of 30 ~ 60 and a length about an oscillating wavelength diminish the sound pressures notably . with the same angle of 45 , the half - wavelength bent plates diminish the pressures , and the one - wavelength or longer bent plates do better
结果表明，当折转角为30 60和折转长度( b )与振荡波长( )相当时( b / 1 . 0 ) ，折板具有显著的削弱振荡声压的效果；折转角45时，折板长度与振荡基频波长之比b /在0 . 5 ，折板就有削弱振荡声压的效果， b /在1 . 0或更大时削弱效果更佳。 |
