多种粮食声吸收的研究

目的 为防止储粮虫害，对多种粮食在自然堆积状态下的声吸收进行了研究。方法采用驻波管法测量了多种粮食的吸声系数。结果报道了粮食颗粒形状、大小及粮食堆积厚度与其声吸收存在的规律，涉及不同粮食间声吸收的比较、颗粒形状相似粮食的声吸收对比、堆积厚度对声吸收的影响、粮食声吸收机理等，结果显示：粮食是高吸收声波的媒质，储粮害虫发出的声信号由粮食内传至表面时的声衰减较大。结论粮食颗粒形状、大小的不同，使其声吸收各异；粮食厚度也是影响其声吸收的一个重要因素，厚度增加，吸声系数随之增大；粮食声吸收受粮食品种影响甚微，这为储粮害虫声检测工作提供了理论依据及资料积累。

A study on sound absorption properties in various types grain

Aim The sound absorption properties of various types and heaped thickness of grain were researched.Methods Use a standing wave tube to measure the sound absorption coefficient of many kinds of grain.Results It shows the relation of sound absorption properties with the shape,size and heaped thickness of grain.The sound absorption properties of various types of grain are compared and so are the sound absorption properties of different types grain in the similar shape and size.The effect of the heaped thickness of grain on the absorption properties was reported and the mechanism of sound transmission was analysed through grain media. It was shown that grain is a highly sound absorption medium. Sound signal produced by pest in stored grain attenuates greatly when it transmits from inside to surface of grain. Conclusion The sound absorption properties have something to do with the shape and size of grain. The heaped thickness of grain is an important factor effecting on the sound absorption coefficient. The sound absorption coefficients increase when the heaped thickness of grain increases. The sound absorption properties have nothing to do with the types of grain material. This study provides theoretic base and accumulating data in detecting sound signal of pests in grain.