But actually , the vector sensor ' s detection gain will be limited by the finite noise counteract for the existence of anisotropic component in the noise field 但实际中，由于噪声场中存在各向异性成分，噪声的声能流只能被有限抵消。
An interesting fact of physics : if you yelled for 8 years , 7 months and 6 days , you would have produced enough sound energy to heat one cup of coffee 有一个有趣的物理现象：如果你大声叫嚷8年7个月零6天，所产生的声能可以加热一杯咖啡。
But noise levels are creeping up there , too : in april the arrival of one device “ about doubled the acoustic energy , ” the report stated 不过该报告又指出，那儿的噪声级也逐渐攀升，因为今年4月加设的一件设备，大概把实验室舱的声能提高至两倍。
Based on the acoustic energy flow detection , the spatial energy flow suppression can obtain time - space gain in direct proportion to time - bandwidth product , which is just the main advantage of the vector transducer 基于矢量水听器的声能流检测器利用空间声能流抵消技术相对于声压检测器可获得与时间带宽积成正比的时空增益。
Thermoacoustic engine is a novel device that can convert heat to acoustic energy . it has advantages such as the simplicity , no moving parts , high reliability , long lifetime and no pollution 热声发动机是将热能转化为声能的装置，它结构简单，没有运动部件，运行可靠，寿命长，无污染，且可利用太阳能、废热等低品位能源为动力。
The analytical mode is based on the theory of sound propagation in layered media . the concept of equivalent parameters is established . the absorption of sound energy by damping layer ' s is represented by use of complex sound impedance 解析模型以分层介质中的波动理论为基础，建立了等效参数的概念，并运用声阻抗的复数表示法把阻尼层对介质层声能吸收的影响都考虑进去，通过比较敷设消声覆盖层前后多层传递损失的差异来获得消声层的效率。
On the basis of the research achievements of the predecessors , combing the research object , that is spherical indoor space , this thesis adopts energy - area method and the equation of the wrap - up line analyzing and researching deeply on the acoustics wave reflection features of spherical indoor space 在总结前人研究成果的基础上,结合本文的研究对象球形室内空间,采用声能面积法和包络线方程从理论上深入分析研究球形室内空间的声波反射特点。
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。
The frame radiated noise is one of the major noise resources of rotary machines , especially for gear case which has close shell and vibrating screen which works in vibrating ways , the frame radiated noise energy account for more than 90 % of total sound energy . so if we could not successfully resolve the problem , the noise of rotary machines would never be effectively controlled 结构噪声是旋转机械的主要噪声源之一，尤其是对于如齿轮箱这类具有封闭壳体的机械和如振动筛这类以振动为主要工作方式的机械，结构振动辐射声能占总声能的比例甚至可以达到90 95 ，因此不解决结构噪声问题旋转机械噪声就不能得到有效的控制。
For conductive fillers / piezoelectric ceramic / polymer composites , based on the piezoelectric and conductive theories , mechanical energy or sound energy can change into electric energy induced by piezoelectric ceramic ' s piezoelectric effect , and then these energy can be dissipated in form of heat energy through conductive network formed by conductive fillers in the system 在导电填料/压电陶瓷/聚合物复合材料体系中，根据压电、导电原理，机械振动能(或声能)可通过压电陶瓷的压电效应转换为电能，并通过体系中导电填料形成的导电网络，将电能以热的形式耗散，从而达到减振降噪的效果。
