声压

In this thesis, the theory, algorithm and applications combined with the project "research on the feature extraction and analysis of XX acoustic vector" are discussed, according to the present development, main problems and practical needs in application of feature extraction of pressure and acoustic vector signals.

本文根据声压和声矢量信号特征提取的研究现状、存在的主要问题以及工程实际应用的基本要求，结合基金项目"XX声矢量特征提取与分析研究"的内容，对目标特征提取及其分类识别进行了理论、算法与应用方面的探讨。

The experimental results reveal that there is no apparent difference in the frequency of sounds generated by the friction and collision between two stones, although the sounds may differ in pressure.

由实验结果可知，摩擦与撞击这两种不同的运动机制所产生的地声音频讯号，除声压强度上会有显著的差异之外，其在频谱上并无太大的差异性存在，这可能是因为摩擦运动基本上也可视其为无数个小撞击运动，因此其所产生之地声声纹基本上大同小异。

Effects of liquid viscosity coefficient on acoustic properties of acoustic low-pass filtering fiber-optic hydrophone are studied theoretically and experimentally.

理论和实验研究了液体粘滞系数对声低通滤波光纤水听器声压灵敏度频响特性的影响。

The analysis of lake experiment's data validate the supposing model of vector sensor and some theories, including the dropping noise-field analysis, the distance testing, the biasing phenomenon of bearing-time course and the spectrum comparison between acoustic intensity and pressure.

湖试数据的实验分析，验证了矢量传感器的模型假设及其部分理论和现象，包括"雨滴"噪声场分析、"拉距"实验分析、方位时间历程的有偏现象以及声强谱与声压谱的比较，其间提出的5种谱级信噪比的估计方法，适用于实验环境的评估。

After studying the theory of combined signal processing with acoustic pressure and particle velocity, a method of direction estimation underwater, which is based on intensity measurement using an acoustic vector sensor, is presented. In the low frequency field with kinds of line-spectra, azimuth angle estimation is achieved based on the probability density statistics and bar graph approach. It can preferably resolve the problem of left/right bearing resolution and estimate the direction of space.

为了对水下目标进行定位，基于声压与振速联合信号处理的理论，研究了复声强法对水下目标信号的定向技术，并使用概率统计和直方图的理论对目标的方位角和俯仰角值进行了估计，在线谱分量存在的低频段对估计角度进行了概率统计，较好地解决了左右舷的分辨问题，实现目标的全空间无模糊定向。

The sound transmission coefficient of normal incidence is presented.

对影响水中双层穿孔板垂直入射声压透声系数的各项因素进行了详细的仿真分析与讨论。

According to this work, the two-dimensional field distribution of continuous sinusoidal wave vertically or obliquely radiated by a linear array of five monopole sound sources is numerically simulated in terms of the different initial acoustic pressure .

在此基础上，数值模拟了初始声压强弱不同的5个点声源组成的线阵列垂直或斜向辐射的连续正弦波在大气中传播时二维声场的分布情况。

So it is much more complicated to measure the sound intensity than the sound pressure.

因此声强测量仪的检定比声压测量仪器的检定要复杂得多。

Compared with the developed sound pressure measurement technology, sound intensity measurement technology is still a young acoustic measurement method.

相对于成熟的声压测量技术，声强测量技术还是一门年轻的声学测量手段。

Fifteen gram pyrotechnic composition with thermite content of 25% can produce the sound pressure level as high as 158.8 dB, and the acoustic frequency is mainly 0~5 kHz, then the acoustic energy decreases with the increasing of thermite content.

当高热剂的含量为25%左右时效果较佳，15 g药剂水下燃烧时的声压级达到了158.8 dB，频率主要分布在5 kHz以下，但当超过25%时声能开始下降。

Do you know, i need you to come back

你知道吗，我需要你回来

Yang yinshu、Wang xiangsheng、Li decang,The first discovery of haemaphysalis conicinna.

1〕 杨银书，王祥生，李德昌。安徽省首次发现嗜群血蜱。