声学的

The influence on absorption coefficient brought from shape choice with cylindrical or cone-shaped cavity, square or hexagonal profile, from different closure as air or water, from different material properties and structure sizes, are analyzed based on the numerical calculations. Some general characteristics are summarized. It shows that lowest resonance frequency of sound absorbent coefficient is inversely proportional to volume of cavity and sound absorbent coefficient is proportional to perforated percentage.

2通过数值方法研究了吸声结构内腔为圆柱腔和圆锥腔、基材的剖面形状为正四边形和正六边形、不同背衬、基材材料特性、尺寸大小对整体吸声效果的影响，总结了这些情况下非旋转对称吸声结构的声学特性变化规律，得出腔体体积越大，吸声系数最低共振频率越低；穿孔率越大，吸声系数越大的结论。

The relationship between in situ target strength and depth of chub mackerel was established by selecting the length composition of mackerel was larger than 90%. Results showed that the in situ target strength of chub mackerel was changed significantly depend on depth up to 8.7 dB. And it indicated that the measurement of in situ target strength of fish with swim bladder should be modified by the relationship of target strength and depth, especially in chub mackerel, it may be led to overestimate the standing crop to 7.4 times of the assessment.

将科学鱼探所收录到的白腹鲭声学资料使用线性回归来检定现场标物反射强度与样本所在水深关系，检定结果显示出白腹鲭在不同水深时所反射的现场标物反射强度均会随著深度改变，并且呈现负相关的显著水准(p.01)，现场标物反射强度变动有8.7dB差异量，对白腹鲭鱼群现存量会超估7.4倍的差异。

Road to Marrakesh" finds him exploring even more exotica than usual, while "Kiss the Earth is a sweet meditation full of unusual percussion lines and cool sonic effects.

在《Road to Marrakesh》中可以发现，他探索比平常更为新奇的东西，而《Kiss the Earth》是一支甜美的冥想曲，充满着不同寻常的打击乐器组合与极酷的声学效果。

Focusing on the problem of the nature of the high velocity surface acousticsmode,we investigate the standard of judging which a wave is a surface wave,present the Green function of a pseudo-SAWand a longitudinal-wave headwave,thus developing the theory for generalized Green's function of surfaceexcitation of a piezoelectric crystal,with the hope to systematize this theory.

本文围绕压电晶体半空间上的高速表面声学模式热点问题，对表面波模式进行了界定，又发展了压电晶体表面激发的Green函数理论，给出了伪表面波及纵波头波的Green函数，从而形成更完整的压电晶体表面激发理论系统。

Thefrequency analysis of the psychoacoustic model can give the inaudible, redundanelements of audio. In this paPer we employ it to gUarantee the inaudibility of theembedded watermark.

心理声学模型的时频域分析主要用于音频数据的压缩编码，这里主要考虑将其用于音频水印算法中去，以便从理论的角度来考虑嵌入水印的不可感知性。

The worst type of room shape is a perfect cube - say, ten feet long, ten feet wide, and ten feet high - because all three dimensions are the same and all three dimensions resonate at the same frequency.

对于声学效果来说，最差的房间形状是完美的立方体——举例说就是长宽高都是10英尺，因为长宽高三个方向的距离都相等，所以三个方向上的共振频率都相同。

Ferroelectric thin films possess a set of unique properties, such as electronic, optical, electro-optic, pyroelectricity, piezoelectricity, for many applications in electronic and optical devices.

由于铁电薄膜具有独特的电学、光学、热学、声学等性能，在光电子学、集成光学、微电子学等高新技术领域中有着广泛的应用前景，八十年代以来铁电薄膜的制备、表征和应用已经成为了世界范围新材料研究中的热点。

This paper reviewed the advances of noise barrier structure in China, and illustrated the development of multiple-edged, T-shaped and Y-shaped top structures used for noise barriers abroad. The development of some new top structures, such as soft surface, quadratic residue diffusers surface of noise barriers was also introduced.

作者对国内声屏障结构形式的现状进行了分析，介绍了国外常见的多重边、T型、Y型等顶部结构的发展情况，同时介绍了声学软表面、平方余数序列表面等新型顶部结构的发展状况。

For the raft, an isoparametric element method and VoigtKelvin model are adopted, which can be used to derive viscoelastic element stiffness matrices, a reform of successive approximation of Rayleigh Quotient is used to solve the eigenvalue problem of the composite structure.

对于筏架结构，采用Voiget-Kelvin模型及等参元法，推导了约束阻尼层单元的刚度阵及将Rayleigh商的迭代步骤加以改进的方法来进行特征分析；对于艇体结构与声学介质耦合部分，采用艇体结构的"干"模态作坐标变换。

But in fact each function has its own acoustical requirements,especially.with their reverberation time,which can notgive same considerations to all functions.

而不同的功能都有各自的声学要求。其中特别是混响时间的差别甚大。难以兼顾各功能的要求。

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。