超声学

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。

It is proposed that the periodic lamella twins can be grown with the aid of this kind of twin structure and it can be applied to acoustic supper-lattice resonancer.

对孪晶形成的可能原因进行了分析，提出了利用该孪晶结构生长周期性聚片孪晶，并应用于声学超晶格谐振器的可能性。

Because of the existence of natural detecting blind area o f general radar on detecting flying object flying in veryˉ low altitude, it is so essential to put forward a suspended bomb t heory which would make use of sound wave's characˉ teristic parameters as its wavelength and spectrum to get the obje ct's direction and position, and to discuss its orientaˉ tion method and embattle model.

由于现有的常规雷达探测超低空飞行的来袭兵器有其固有的盲区，作为雷达的必要补充，利用声音的大小、频谱等特征能够反映声源的方位等特征参数的特性，提出了一种被动声学探测悬浮弹理论，并对其定位算法和布阵模式进行探讨，目的是防御拦截低空超声速巡航导弹。

It turns out that the flow and noise characteristics are quite complex and different from those of incompressible jets due to existence of quasi-periodic shock cell structures.

超声速射流是一般工业和军事工业中得到广泛应用的重要流动现象，对其流动特性和声学特性的研究，在实际应用和学术研究上有重要的理论价值和实际意义。

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。