查询词典 uniform velocity

Regarding the speed along with the displacement even change's uniform non-uniform linear motion, its acceleration should define like this: At the unit displacement the speed change (the physics significance is: The speed along with the displacement change "the speed"), like this has:, the acceleration unit should be , Expression speed change which causes in proportion to as a result ,of the speed action of force.if the final velocity is 0, acts according to , namely .

对于速度随位移均匀变化的匀变速直-运动，它的加速度应该这样定义：在-位位移上速度的变化（物理意义是：-速度随位移变化的"快慢"），这样-有：，加速度的单位应该是，表示由于正比于速度的力作用而引起-速度的变化，其中。如果末速度为0，则根据，即。

According to this understanding, this thesis tries to modify PSO algorithm in order to improve its quality of solutions. The main approches include: using uniform design to ensure the uniform distribution of initial particles in the design space; adding mutation operation to increase the diversity of particles; decreasing the maximum velocity limitation and the velocity inertia automatically to balance the local and the global search efforts; developing a new approach to treat the design variables exceeding the bounds; using extensive local searches to escape local minimum. The overall effect of these approaches can yield better results for most test problems.

有鉴於此，本文针对粒子群演化法之流程参考相关文献并稍作改变，使得粒子群演算法在结果的收敛上更具优势，本文的主要改进的方法包括：应用均匀设计的概念使得初始的粒子可以更均匀地分布在空间上；利用突变增加粒子之间的差异性与多样性；利用适当控制的最大速度限制及惯性权重控制，达到区域搜寻与全域搜寻的效果；应用新的边界处理机制处理设计变数超过上、下限的问题；利用区域强化搜寻针对粒子附近地区，再作进一步的搜索以得到更佳之结果；将各种方法综合后配合粒子群演算法使用，可以得到不错的结果。

Firstly, based on the method of pressure-velocity coupling introduced by SIMPLE algorithm and a revised method of solving the unsteady equation of stream function and vorticity on uniform grid, a special algorithm called primitive-variable-time-dependent approach is formed in the present study. In this algorithm the Navier-Stokes equation in primitive variable form is solved by using the time-dependent approach on non-uniform staggered grid system. The second-order accuracy finite difference is used for the first and second partial derivatives of all variables of the convective terms and diffusion terms.

首先，本文在SIMPLE算法系列处理速度与压力耦合问题的思路和均匀网格下改进的关于流函数涡量方程的数值求解方法的基础上，将非定常原始变量Navier-Stokes方程的求解推广至非等距交错网格剖分，形成了具有本文特色的原始变量时间推进方法，其中对流项和扩散项中各变量的各阶导数均采用二阶精度公式，包括温度在内的离散方程组采用ADI迭代方法求解。

The model was designed with 1: 4 scale, strips width of protection tillage and tradition farming are uniform, to analyze the construction characteristics of the wind velocity flows, the wind velocity lowering rate compared with the wind velocity of farmland and aerodynamic roughness along lengthways of strips under the different experiment wind velocity, diverse width of strip, dissimilar residual stubble density and residual stubble height term.

模型比例尺取1：4，保护性耕作带带宽和裸露带带宽相等，分析不同实验风速、不同带宽、不同作物残茬密度及不同作物残茬高度情况下，风速流场特征、沿带纵向对应裸地风速降低率状况和空气动力学粗糙度。

Programs, AFITA and SHET, are developed, which can be used to compute the critical velocity for straight tube arrays and U-tube arrays of all sorts of tube arrangements in uniform and non—uniform flow and to calculate the response of tube due to flow induced vibration.

6开发了软件AFITA、SHET，能进行三角形、矩形排列的U型管和直管管阵、均匀流和非均匀流的临界流速分析，单根管自由振动和湍流诱发振动分析。

Moreover, the hot compressive deformation behavior of the RS/PM AZ91 magnesium alloy and AZ91 alloy matrix composite were also investigated, the conclusions are drawn as follows:1. The processing parameters of the atomization-twin rolls quenching technology were optimized as follows: the diameter of the nozzle 1mm, the wheel velocity 25m/s, the pressure of atomization gas 0.3MPa and Ar gas for melt injection 0.1MPa. The RS AZ91 alloy flakes exhibited fine and uniform microstructures. When the flakes were extruded at 673K, extruded velocity of 0.1mm/min and extrusion ratio of 25:1,the magnesium alloy rods with clean surface, uniform dimension and excellent mechanical properties were obtained.2. The RS AZ91 magnesium alloy powders prepared by atomization-twin rolls quenched technology exhibited fine equiaxed grains with the grain size of 1-3μm, the phase constituent included supersaturate solid solution phaseα-Mg and miner fineβ-Mg_(17)Al_(12) phase. The as-extruded materials also exhibited equiaxed grains with the size of 5-7μm and a large number of fineβ-Al_(12)Mg_(17) and fewer AlMg_2Zn phases were detected in the alloy.

本文还研究了快速凝固/粉末冶金AZ91镁合金热压缩变形流变应力行为，快速凝固/粉末冶金法原位生成Mg_2Si增强AZ91镁基复合材料，经过系统的研究，获得如下结论：1、雾化-双辊急冷法在下列工艺参数组合下：双辊线速度25m/s；喷嘴直径1mm；熔体压射压力0.1MPa；雾化气体压力0.3MPa。，可获得宏观尺寸细小、微观组织均匀细小、综合性能优良的的快速凝固AZ91镁合金细碎箔带，快速凝固箔带在挤压温度为673K、挤压速度为0.1mm/min，挤压比为25：1时，可获得的外表光洁、尺寸均匀、组织性能优异的镁合金棒材。2、雾化-双辊急冷法制备的AZ91镁合金粉末态为细小等轴晶组织，晶粒尺寸1-3μm，组织为α-Mg过饱和固溶体和微量的细小β-Mg_(17)Al_(12)相组成；粉末挤压棒材为等轴晶组织，晶粒尺寸5-7μm，组织中含有大量细小的β-Al_(12)Mg_(17)以及AlMg_2Zn析出相，室温力学性能，抗拉强度383MPa，屈服强度275MPa，断后伸长率7.5%。

The paper introduces the working principle and structure of velocity type geophones,expounds the prerequisite for producing uniform magnetic field and the influence of the uniform magnetic field on geophone′s distortion.

文章在介绍了速度型检波器的结构和工作原理后，阐述了检波器中产生均匀磁场的必要条件及均匀磁场对检波器失真度的影响。

The results indicate the velocity and temperature in different flow channels of a planar fuel assembly are relatively uniform, and the velocity and temperature in the same flow channel are also uniform.

数值计算结果表明：燃料组件不同流道的流速分布和温度分布均较均匀，单一流道的流速分布和温度分布也较均匀。

This one-way wave equation fits eikonal equation and transport equation corresponding to full acoustic wave equation in travel-time and first order amplitude. According to the perturbation theory often used in inverse solution, we split the velocity field into intraformational constant velocity background and variable velocity disturbance. Then we calculate time-shift quantity of migration and amplitude correction coefficients for wavefield depth continuation in total uniform formation and each formation.

基于反问题求解中常用的摄动理论，把速度场分裂为层内常速背景和变速扰动，求得整个均匀层波场深度延拓的偏移时移量及振幅校正系数、各层的偏移时移量及振幅校正系数，从而得到一个基于傅里叶有限差分法的双域保幅叠前深度偏移算子方程。

From dead-end to open-end, surface velocity increases gradually if the filter passage is shorter and surface velocity of both ends is large than that of middle section if the filter passage is longer. Compared with cylindrical filter, the distribution of surface velocity of conical filter is more uniform.

当过滤通道较短时，过滤元件表面速度沿过滤元件轴向逐渐增大；当过滤通道较长时，过滤元件两端的过滤速度比过滤元件中部的大；同圆柱形过滤元件相比，锥形过滤元件过滤速度的分布更为均匀。

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。