声速

The elementary principle of the method is to get out acoustic information from acoustic solid medium firstly through Bragg diffraction ,and then to measure the difference of deflection angular from reference beam of light.

该方法的核心是通过声光布喇格作用，把SAW陀螺效应引起的声速变化信息寄载到布喇格衍射光中，通过检测布喇格衍射角度推算出固体介质的旋转角速度。

Using the color changing information of phase change paint, this technique mainly applies an image capturing and processing system which consists of a CCD video camera and a computer to measure the characteristic parameter and the heat transfer rate of model surface in hypersonic flow.

该技术主要是运用CCD摄像机与计算机组成的图像采集与处理系统，利用涂料发生相变的颜色变化信息，测定高超声速流场中模型表面气动加热的特性参数和热流分布情况。

The concept of compressible fluid flow is usually employed for gases moving at high velocity, unlike the concept of incompressible flow, which is used for liquids and gases moving at a speeds well below sonic velocity.

的概念，可压缩流体流动通常是受雇为气体运动在高速度，不同的概念，不可压缩流动，这是用于液体和气体运动在速度远低于声速。

The increments of the contraction ratio and the convergence angle strengthen the internal compression.

用N-S方程模拟了一系列典型二元高超声速进气道内压缩通道及隔离段模型，模拟发现内压缩通道及隔离段增压比、温升比和总压恢复系数等性能参数主要受面积收缩比、内压缩通道收缩角、隔离段长高比等几何参数以及内压缩通道进口马赫数、密度、附面层厚度等流动参数的影响。

Jet counterflow is usually used for the motion state control of aerospacecraft such as a missile, a shuttle, a satellite, and a spaceship, etc.

超声速射流逆流通常用于导弹、航天飞机、卫星和飞船等飞行器运动状态的控制。

The improved experiment device of interference of sound wave can feel the interference countervail and strengthening of sound in ordinary lab, and measure the sound velocity.

本文给出了改进声波干涉实验装置的具体方案，该改进装置可在普通实验室内感受声音的干涉相消和干涉加强现象，并能测定声速和频率。

The methodusing cross correlation analysis and FFT technique is introduced to analyze digitized pulse echosignal in ultrasonic measurement.

与此同时，针对影响声弹性测量结果的超声信号分析与处理技术，提出了基于相关分析和FFT技术的声速测定理论与方法。

He found that the sonic surface was, in general , discontinuous

他发现声速面通常是不连续的。

This paper referred to simulating the supersonic double cone inlet" s flow field of ramjet pill assisted range projectiles at a variety of working circumstances, pressure contours, density contours and Mach number contours of inlet" s flow field were given When cone combination, relative location of cone core and cowl lip, the pressure of outlet, inflow Mach number and angle were changed, flow field and performance parameters of inlet can be affected. Simultaneity, productive mechanism and inducing factors of the inlet surge were also discussed. Then the best working conditions and the best model of inlet were obtained.

本文对冲压增程弹丸所用发动机的双锥超声速进气道在各种工况条件下的流场进行了数值模拟，给出了进气道流场的等压线图、等密度线图和等马赫线图，从而观察在不同的锥尖角组合、锥芯与外罩唇口的相对位置、出口反压、来流马赫数和攻角时，对进气道流场及性能参数的影响，并探讨喘振现象的产生机理及诱导因素，以便确定最佳的工作状态，得到最优的进气道模型。

The structure and properties of coating are observed and analysed by means of Scanning electron microscopy and X-ray diffraction, and compared to electroplate d layer.

采用超声速火焰喷涂技术制备了镍基涂层，利用扫描电镜、X射线衍射仪等对涂层结构和性能进行了观察和分析，并与电镀涂层进行了对比。

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。