查询词典 muzzle velocity

The sensitivity analysis which is based on the calculus of variations is used in the shape optimization. The design velocity field is solved by Herrmann method. An example shows that both the quality of the FEM mesh and the efficiency of the computing of the design velocity field are improved by Herrmann method.

算例表明优化过程中采用Herrmann网格均匀化法求解设计速度场，可以提高优化过程中网格的质量，速度场的求解效率也得到极大的提高从而优化的效果和效率都有明显提高。

At the same time, combining with the actual condition of delivery pipeline of our country and some prevalent leak detection and location methods, this paper raised a method, which is based on wavelet analysis and negative- pressure-wave to detect and locate the leakage. Jobs in the paper are as follows:As affected by gas density, pressure, specific heat and pipe material, the velocity of negative-pressure-wave improved depending on the energy conservation. At one time, taking the affection of velocity of gas flow, the location formula was modified in some degree.When locating the leaks with location formula, the iterative approach algorithm was adopted as a new method to increase the location accuracy level of system.Multi-scale decomposition and reconstruction of wavelet transform is utilized to filter the noise of negative-pressure-wave, which was brought by leakage. With the capacity to detect the signal singularity fast and accurately, wavelet transform was used to catch the break point of pressure signal. The work improved the accuracy of At in location formula, accordingly improved the location accuracy.Wavelet is a suitable tool for signal analysis. The distinct character is that the mother-wavelet is of optional. That means choosing different mother-wavelet will get different analysis result. So we studied how to choose mother-wavelet and its scale for signal singularity detection. The method is to choose a wavelet by regularities of the wavelet and the signal.Finally, a plan, which bases on SCADA system for inspection and detection of natural gas leakage, is proposed in the article.

其中，主要进行了以下几方面的工作：针对泄漏产生的负压波在管道中的传播速度受媒介的密度、压力、比热及材质等因素的影响，而非声波在空气中传播的速度，本文利用能量守恒原理，对其进行了修正；考虑到管内气体流速对压力波速的影响，对原始的负压波定位公式进行了一定程度的改进，并在利用定位公式进行泄漏点定位时采用逐步迭代逼近算法，提高了系统的定位精度；利用小波变换的多分辨率分解和重构技术，对采集到的管道发生泄漏时产生的负压波信号进行了降噪处理；并利用小波变换技术对信号奇异点的快速、准确的识别能力，对经上述消噪后的负压波信号进行了奇异点捕捉，精确捕捉的结果提高了定位公式中上下游站点采集到的负压波奇异点的时间差△t的精度，从而进一步提高了定位的精度；考虑到小波变换是一种基波可变的信号分析工具，也就是说，不同的小波基波对信号分析的结果将有很大差别，这势必影响最终的处理结果，因此，我们又对比分析了本课题中小波基及尺度的选择问题，依据规则性系数相似性原理对母小波的选择进行了探索性研究；最后，还提出了基于SCADA的泄漏检测与定位系统的软件开发构想及系统的嵌入方案。

Relati/onships between the relative height and the mean velocity explain that the effect to slow the velocity down of Centipede grass is the best, that of Bermuda grass is the second, and that of Carpet grass is the worst whatever the bottom is yellow loam or red loam.

经实验结果推得理论解合理，由相对高度与流速之关系图可看出：在土壤为黄壤及土壤为红壤的状况下，减缓流速效果皆以假俭草为最佳、百慕达草次之，最差者为类地毯草。

This feature gives a reasonable explanation for the mechanism of CAS. The phase velocity of diffraction fields for uniform plane wave on a circular aperture has been investigated. It is shown that diffraction can result in subluminous phase velocity at certain points of optical field in vacuum.

如果相对论电子能够注入到这一通道内，那么它与激光场间的相移就可能变得非常小，从而能够长时间地保持在加速相中得到极高能量。

We have studied a model of a non-Newtonian viscous compressible fluid in 3D bounded domains, in which the viscous part of the stress tensor satisfies the coerciveness condition and the values of the growth condition ., are positive constants. Here is the tensor of the velocity gradient, is the strain tensor and ,which depends on the tensor of the velocity gradient, is the hefts of .

对满足强制性条件，以及增长性条件的非牛顿粘性可压缩流体在三维有界区域中的流动进行了研究，其中和为正常数，为速度梯度张量，是偏应力张量，为的分量，它依赖于速度梯度张量。

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 survey of similar Orbal oxidation ditch is focused on the velocity distribution of concentration ellipse shape and concentric circles shape represented in oxidation ditches, analyzes the rationality of its device allocation and the problems shown in velocity profile, proposes the improved treatment.

现场同类Orbal 氧化沟流场的实测研究了椭圆形和圆形两种Orbal 氧化沟的水力现象，分析其设备配置的合理性，针对流速分布中出现的问题进行分析并提出了改进的措施。

Some parameters such as Indoor radiation heat transfer, convective heat transfer, MRT, OT, radiation heat transfer coefficient, convective heat transfer coefficient, and PMV-PPD were calculated under a steady condition. From the result, we can conclude, when operation under the combination system and worst-case test, if floor temperature is about 21℃, supply air temperature is 21℃, air velocity is 1m/s, the equlvalent coefficient of heat transfer between floor temperature and OT is 13.6w/m2k, where 5.68w/m2k is equlvalent coefficient of radiant heat transfer, 9.48w/m2k is convective heat transfer coefficient. And when air velocity is higher, supply air temperature is lower, the radiant heat transfer between floor and others is lower. In the whole experiment, the floor temperature was keeping above the indoor air dew point, and condensation was not appeared.

通过分析计算，在复合式系统运行中，最不利室外环境下，当地面温度维持在21℃左右，送风温度21℃，送风风速1m/s，此时地板对作用温度的当量综合换热系数为13.6w/m2k，其中当量辐射换热系数为5.68w/m2k，对流换热系数为9.48w/m2k，并且送风速度越高、送风温度越低，地板与其他壁面的辐射换热量有一定程度的降低，但总供冷量增加；在整个实验中地板温度始终高于地板上层空气的露点温度，并未发现有结露现象；室内空气温度梯度能满足0.1m-1.1m的温差小于3℃的要求，并且适当提高送风温度可以进一步提高人体的热舒适性。

We suggest a consistency principle to derive velocity models. It states that we should search for an imaging velocity field that yields the same image position independent of source or receiver position.

建议用一个相容原理来导出速度模型，这就要求寻找一个合适的成像速度场，该速度场不受震源和接收器位置的约束而有相同的成像位置。

Based on the variable separation method, the governing equations for the film thickness problem have been solved. A reasonable consistent condition of the momentum equations has been found and solved. Based on the methods ofmathematical physics, series expansion solution of the velocity filed in the film has been derived. A boundary condition at the boundary of the spray area was given and the velocity slip phenomenon has been considered.

基于电子器件喷雾冷却技术的研究现状和研究热点，本文对喷雾在热源表面形成的冲击液膜流动及厚度模型、基于CHF(Critical Heat Flux，临界热流密度)准则的倾斜喷射喷嘴轨迹、喷嘴距热源换热最优时的高度、倾斜喷射实验以及针对动态喷射的电磁驱动器件的吸合问题等方面进行了研究：针对圆锥形轴对称喷雾冷却系统，在对喷雾区域进行划分的基础上，引入滑流边界条件，在提出圆锥状喷雾假设的基础上，建立了喷雾区域雾滴密度连续介质等效模型。

You can do some assertiveness training.

你可以进行一些自信训练。

We were well on the path to making a rear-wheel-drive global platform," says Mays."

我们正致力于建立一个后轮驱动的平台，"Mays这样说道。"