查询词典 sound pressure

To measure, calculate, display, print sound intensity sound pressure, sound power, three dimensional sound intensity spectrum, equal intensity contour are all deeply studied.

本文就声强、声压、三维声强谱、等声强线以及A计权、1/3倍频程的测量、计算、显示、打印等进行了深入的研究，并编制了一整套运行于Windows平台的图形化多文档界面声强测量分析软件。

Based on the simple global noise source, take the noise which is cared by people into account. Get the sound pressure level after processing the noise sources sound pressure. Educe the allowable value of the upper limit, through linking to the sound pressure level which is permitted. Taking the value into the reliability modals established before, found the diplex integral mathematics modals that is restricted.

考虑约束因素的影响，引入人们所关心的噪声，以结构简单的球形声源为基础，在对声源声压做了相对处理后，得到其声压级，结合许用声压级指标，求得许用频率上限值，将该值代入已建立的防共振模糊可靠度模型，建立有约束防共振模糊可靠度计算的双重积分数学模型。

The interior sound pressure levels and exterior sound pressure levels of the complex box structure excited by an exterior point load are measured, and a good agreement between the theoretical results and the test results shows that the theoretical method and corresponding results are correct.

通过对几种具有理论解的结构辐射声场的分析，验证了本文理论的正确性，研究表明本文方法具有很高的精度；同时对复杂箱形结构进行了实验验证，在实验室条件下测量了复杂箱形结构在外部点载荷激励下的内、外部辐射声压级，与理论预估值比较表明，二者具有良好的一致性，进一步证实本文所建立的理论预估方法是有效的。

On the aspect of error compensation, the system using the geometric average sound pressure instead of the arithmetic average sound pressure to get the sound pressure of the measurement point. This method not only reduces the high frequency error in the sound intensity measurement, which compensates the finite difference approximation error, but also greatly reduces the computation of the sound pressure spectrum.

误差补偿方面，课题采用几何平均声压代替通常的算术平均声压来计算双传声器法的声场声压值，这样不仅可以有效的减少声强测量中的高频误差，对有限差分误差起到了补偿作用，而且还大大减小了声压谱计算中的计算量。

The results showed that,the sound pressure level increased significantly when narrow transverse groove was used;the effect of speed on the sound pressure level was greater than loading;the noise of S-shaped straight groove was lower,and the difference of sound pressure level between positive and negative rotation was small;the sound pressure level of 15° oblique groove was higher than 0° and 15° alternate groove,but the difference of sound pressure level between positive and negative rotation of 0° and 15° alternate groove was bigger.

结果表明，无论加刻什么类型的横向细沟槽，声压级都大幅升高；速度对声压级的影响程度大于负荷；在3种类型的横向细沟槽中，S形直沟槽噪声较小，且正、反转时声压级差异小；15°斜沟槽声压级较0°与15°交替排列沟槽略高，但0°与15°交替排列沟槽的正转和反转声压级差异较大。关键词：轮胎；轮胎噪声；胎面花纹；横向细沟槽中图分类号：TQ336.1；TB533+。2文献标识码：B文章编号：1006-8171(2009)

Firstly, a signalized point is stuck on a moving object to be tested, a microphone array and two video cameras are arranged, and the video cameras are demarcated to obtain a projection matrix; sound pressure signals of a sound source in the moving object to be tested are obtained by the microphone in an array mode, the dynamic video of the moving object to be tested is obtained and disassembled into an image by the video cameras; the signalized point on the moving object to be tested is identified in the video image and the matched signalized point is treated with three-dimension reconstruction to obtain the spatial location of the moving object to be tested; the sound pressure signals are treated with beam forming treatment to obtain a sound field characteristic function scattergram of the moving object to be tested, the video image is treated with spatial coordinate superposition frame by frame and restored into a dynamic video image.

首先在被测运动物体粘贴标志点，布置传声器阵列和两台摄像机，对摄像机进行标定，得到投影矩阵；传声器阵列获取被测运动物体中声源的声压信号，摄像机获取被测运动物体的动态视频，将动态视频拆解成图像；在视频图像中识别出被测运动物体上的标志点，对匹配后的标志点进行三维重构，获取被测运动物体的空间位置；对声压信号进行波束成型处理，得到被测运动物体的声场特征函数分布图，将其视频图像进行逐帧空间坐标叠加，并还原成动态视频图像。

The sound intensity level, the sound pressure level, and the index of sound pressure – residual sound intensity level if verified.

检定声强级和声压级测量的偏差和声强仪的声压－残余声强指数。

The minimum fluidization velocity has a minimum value when the frequency of sound waves is 120Hz and it will decrease as the sound pressure level increases. The degree of sound attenuation will increase while bed material is higher and the fluidization quality of fine particles will become poor and the minimum fluidization velocity will increase. Compared with TiO2, the SiO2 fine particles have a better quality of fluidization at the same fluidized conditions.The cluster/subcluster model and oscillators model are used to describe the fluidization characteristics of fine particles in a sound-assisted fluidized bed. The theoretical calculations show that the minimum fluidization velocity umf is decreased with the SPL increased at the same frequency of sound and the quality of fluidization is better.

论文还系统的考察了声压和频率对纳米SiO2和TiO2颗粒流化特性的影响，结果表明：在频率一定的情况下，声压越高，流化床中形成的聚团尺寸越小，最小流化速度越低，流化质量越好；当声压低于120dB时，声场对超细颗粒流化特性的影响减小，当声压大于130dB时，则能显著改善流化效果，使流化床内的颗粒聚团明显减小，最小流化速度明显降低，粉体带出减小；声压一定，频率为120Hz左右时，最小流化速度最低，此时流化床中形成的聚团尺寸最小，流化效果最好；超细颗粒达到较好的流化状态存在一个最佳频率范围，随着声压增高，这个频率范围将增大。

There are two modeling methods used in this research area, that is analytical method and numerical method. Analytical method can be used to analyze the sound pressure within enclosures, and to analyze the control mechanisms theoretically, however it can be used for regular cuboids only. Numerical modeling method can manage enclosures with arbitrary boundaries, nevertheless, the results obtained using this method are dispersed sound pressure. It is hard to conduct real time control with this method. The two modeling methods have their own inherent defects.

对于封闭空间的结构声辐射，目前有解析建模和数值建模两种建模方法，解析建模方法可以从理论上对系统进行分析，探讨消声机理，但它只适用于长方体等规则封闭空间；数值建模方法不受空间边界形状的限制，得到的是空间声压的离散结果，难以用于实时控制，两种方法都存在着局限性。

In this study,we took a measurement of sound pressure distribution, sound field variability, and effects of frequency shift on sound pressure levels at reference points of pure tone in the diffuse sound field.

本文通过对纯音声压分布、声场变异以及频率漂移对参考点声压级影响的研究发现，扩散场中纯音声压分布的均匀性虽不如啭音，但在某些范围其能量仍可充分扩散，这些区域声场测试结果受受试者头位改变和／或频率漂移影响轻微。对20名重度感音神经性耳聋患者的测试结果证实了上述结论。

Since historical times,England ,where the early inhabitants were Celts, has been conquered three times .

从有历史以来，英国，在此地早期居住的是凯尔特人，已经被征服了三次。

Bluetooth OBEX File Transfer Enables the sending and receiving of files on your phone via Bluetooth.

蓝牙OBEX文件移动允许经过蓝牙传送和接受文件。。。。