声速

These phenomena indicate that a lot ofwaxes have crystallized in waxy oil and the oil is jelling.

含蜡原油声速和衰减系数的变化对应于含蜡原油中有大量蜡晶析出与凝结的过程。

In our experiments,the propagationvelocity and the coupling coefficient for the high-velocity surface acoustic mode ismeasured on a free surface as well as on a metalized surface.

在实验中，采用四种经常使用的压电晶体，对这种表面高速模式进行声速和耦合系数的测量，分别在自由表面和金属化表面进行。

By using the pules echo ultrasonic technique with 10 MHz. the ultrasonic velocities of the amorphouse carbon and their pressure dependence have been measured in the pressure up to I GPa. We have calculated its second, third- and combinations of forth-order elastic constants, and have researched its Gruneisen constant.

本文报导了利用10MHz超声脉冲&回波重合法&，测量非晶碳的声速及其在1GPa压力以内的变化规律，得到非晶碳的二阶弹性常数，三阶弹性常数及组合的四阶弹性常数，从而进一步计算和研究非晶碳的Gr？

Moreover, the accuracy analysis for different measurements and parameters(such as time measure error, azimuth measure error, buoys error, baseline length and sound velocity fluctuation) are given respectively. To make the best use of the observation datas, the weighted least square localization algorithm is used to improve the accuracy in bistatic sonar. The simulation results show that the positioning accuracy of this algorithm is higher than the other four algorithms, with which the positioning accuracy in stations areas and side areas can be improved effectively.

同时，通过对系统各个因素，如系统的各观测量的测量误差、站址误差、基线长度、声速波动等参数对算法性能的影响，得出了各方法定位误差的分布规律；为了充分利用双基地声纳系统的观测数据，提高系统的定位精度，采用加权最小二乘方法对系统的数据进行优化处理，仿真结果表明该方法定位精度明显高于基本方法的定位精度，能有效的改善发射站和接受站侧边区的定位精度，且定位性能受站址测量误差的影响较小。

The supersonic flow and combustion were simulated by the method of large eddy simulation.

并采用大涡模拟方法数值模拟了超声速流场中气动斜坡的流动及燃烧特性。

The results demonstrated that supersonic airflows will form a low-frequency oscillation in the combustor after the inlet cover is open, and the attenuation of the oscillation is very slow.

计算结果表明，在进气道整流罩打开以后，超声速气流会在燃烧室通道内形成振幅衰减较慢的低频剧烈振荡。

Part three: numerical simulation on the supersonic chemically reacting flow field in the combustors.

主要工作包括三部分：第一，雾化后的燃料液滴和气态燃料在燃烧室的超声速气流中混合问题的数值模拟。

The results show that the cavity can change the waves in combustors,and facilitate the mixing of hydrogen and air for easier combustion.

采用有限体积法求解可压缩N-S方程及组分方程，对三种不同结构的超声速燃烧室进行了数值研究。

Finally,the conclusion is draw that it is necessary to make that tentative study of the hypers...

最后进行了讨论：高超声速控制技术是一个全新的领域，目前国内在这方面研究较少，进行这方面的尝试研究是非常有必要的。

This is impractical for engineering problem. It is necessary to break the shear layer in order to enchance mixing. It is very useful for combustor design with cavity or dual-cavity. In such combustor the fuel jet can break the

要使超声速混合增强，必须打破稳定的剪切层，燃烧室采用凹槽或双凹槽设计是一种行之有效的方法，它产生的燃料射流就能打破剪切层，从而使混合和燃烧效率进一步提高。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。