The attenuation coefficient shows approximately linear behaviour with frequency over the frequency range used, and the attenuationslope increases with the void content.
结果表明：超声衰减系数与频率之间存在线性关系，而且其斜率随孔隙率的增大而增大。
2
A large number of trees, landscape, lush natural attenuationslope construction manpower carving, let all the buildings in the height difference between the natural growth of the scattered.