Acoustics . recommended practice for the design of low - noise workplaces containing machinery . part 3 : sound propagation and noise prediction in workrooms 声学.含机械设备的低噪音工作场所用推荐操作规程.第3部分:工作间的声音传播和噪声预测
Hanford and long first set up a virtual " box " filled with about 10 million carbon dioxide molecules floating about randomly , at the same density as the martian atmosphere 多数模拟声音传播的数值模式，把介质视为连续体来处理：不去考虑分子个别行为的影响，只以整体的平均性质来做计算。
Although low frequency sound travels further than high - frequency sound , calls at higher frequencies give the bats more detailed information such as size , range , position , speed and direction of a prey ' s flight 尽管低频声音比高频率的声音传播远，但高频叫声使蝙蝠能获得诸如大小、范围、位置及猎物飞行的速度和方向等更加详细的信息。
Considering the time delay of sound transfer , a least square line - of - sight location method is presented in this paper . 4 . filtration matrix is developed to make the problem of multiple target tracking in net can be regarded as a problem of multisensor - multitarget tracking in a same region 利用最小二乘理论，研究了多静止站单目标无源纯方位定位方法，给出了多静止站单目标的视线交叉定位算法，同时针对声音传播的延时特性，提出了处理具有延时特性的最小二乘迭代视线交叉定位算法。
According to the direction of transmission of voice , the right teachers li ji zheng home again on the house and the surrounding environment after observing that if this voice is not within the house by the sound source , it is only possible , this is a sound external sound source through a beep will transfer to the media houses within the past 根据声音传播的方向，李积权老师再次对郑家的房子以及周围的环境进行观察后认为，如果这个声音不是房子内部的声源发出的，那唯一的可能就是，这个声响是由一个外界的声源发出的响声通过一定的介质传递到房子内来的。
The paper analyzes the characteristic of aerodynamics with structure of helicopter propeller blade , dissertrates vortex theory and the theory about gliding air field which produce the power of helicopter propeller blade . at the same time it also deduce the method of computing the induced velocity produced by helicopter propeller blade with vortex theory . at last , an influcence to the spreading of sound is discussed 并且将两种定位算法进行了比较，说明了优劣；结合直升机的结构分析了旋翼的空气动力特性，论述了直升机旋翼产生拉力的滑流理论和涡流理论，结合涡流理论论述了直升机旋翼流场诱导速度的计算方法，在此基础上分析了直升机旋翼流场对声音传播的影响。
