速度分布

The research of both theories and practices of gridding in the dissertation shows that: Linear interpolation based on triangulation is simple computationally and fast, but its gridding results isn't smooth and its precision is low; Multiquardric method is also simple computationally with high precision and good effect, but its gridding is slow because it is based on global calculation; Minimum curvature method is fast with high precision and good effect, but its gridding quickly degrades over areas with sparse data control when grid spacing smaller than the actual grid spacing is used; Ordinary Kriging method is high-precision, but its gridding is slow because of large calculation; Inverse interpolation is a computationally fast, efficient and robust method with high accuracy and perfect effect, and its gridding results of different gridding orientations are basically identical. Inverse interpolation is suitable for thegridding of geophysical irregular data, especially for large-scale geophysical irregular data.

本文的方法研究和数据试验分析表明：基于三角网的线性插值法计算简单，速度快，但其网格化结果不光滑，精度不够；多元二次函数法计算简单，网格化精度高，效果良好，但它是基于全局计算的，计算速度较慢；最小曲率法计算速度快，网格化精度高，效果良好，但其在稀疏控制点的网格化容易出现振荡现象；普通克里格法网格化精度高，效果良好，但其计算量较大，一般计算速度慢；反插值法网格化计算稳定，速度快，精度高，效果好，而且在网格化方向不同的情况下其网格化精度效果都达到基本一致，适合于地球物理不规则分布数据的网格化，特别是大规模地球物理不规则分布数据的网格化。

Numerical simulation results reveal that the tangential, axial velocity and radial velocity in the annular space are asymmetric distribution, and basically symmetric distribution in the separation space.

在旋风分离器的三维速度中，切向速度在环行空间具有明显的非轴对称分布，向下进入分离空间后很快发展为轴对称分布；轴向速度和径向速度在环行空间存在一定的非轴对称性，而到分离空间后基本上是轴对称分布了。

The simulation results of the model are consistent with the results of wind tunnel experiments. It shows macroscopically the rationality of the distribution function of lift-off velocity of saltating sand grain.

数值计算结果显示，风沙流垂向质量百分浓度与风洞实验结果符合得较好，这在宏观上说明沙粒起跳初速度分布函数的合理性。

The number of lift-off sand grains percent time percent sand bed area Based on the lift-off velocity distribution function of saltating sand grain, this thesis gains the number of lift-off sand grains percent time percent sand bed area which ranges from 6796 to 8846900 number/(s·m2) by combination motion model of single saltating sand grain and some motion parameters of saltating sand grains and the flux of wind sand current from wind tunnel experiment.

单位时间单位面积沙床起跳沙粒数利用本文获得的沙粒起跳初速度分布函数，结合沙粒跃移运动学模型以及风洞实验中获得的沙粒跃移运动参数以及输沙量，反演出一定风场条件下单位时间单位面积沙床起跳沙粒数，变化范围6796-8846900个/(s·m2)，并满足。

By changing the nozzle structure and the injection control parameters, the distribution nephograms of pressure and velocity under different conditions are obtained.

通过改变喷嘴结构及喷吹控制参数，采用数值模拟方法获得各种条件下的压力、速度分布云图。

When gas superficial velocity was about equal to liquid superficial velocity,the probability density function of liquid holdup had a twin-peaked,when liquid superficial velocity was constant,one of the peaks would fade out and disa...

在段塞流动中，当气相折算速度和液相折算速度相差不大时，持液率概率密度函数呈双峰分布；当液相折算速度不变时，随着气相折算速度的增大，持液率概率密度函数第2峰值逐渐减小，直至消失而变为单峰分布；利用这一特征可初步确定段塞流动中气、液相流量相对大小。

Tail gate of flume ; flow pattern ; distribution of velocity ; diameter of orifice

水槽尾门；流态；速度分布；孔径

In the process of building and using the mass concrete structures, because of the effect of out-side condition and themselves, some faults will form in the structure, these faults will effect the bearing capability and endurance Using nondestructive testing method to test the concrete"s quality and diagnose its healthy, which has the significant sense in assessing the safety stability and research of the administering diseasesThis dissertation mostly researched the testing methods in the mass concrete structure, discussed the principles, methods, features, sphere of application of the ultrasonic testing in the mass concrete structure with faults, used dynamic FEM to simulate the testing process, discussed when the concrete structure with cracks is under the effect of the pulse, how the elastic waves propagate and what are their changing feature, Researched the principles of the first-arriving waves" phase when the cracks" depths are not same, obtained the relation between the inversion point and the cracks" depth, which has the direction sense in the application of projects,The second part of this dissertation is CT , which used the ultrasonic wave running through the tested-substance to get arriving-time of the ultrasonic wave, then inverse the image This dissertation drawed one CT program which can well present the different little cells ultrasonic wave velocity profiles of the substance, thereby to diagnose the quality of the part of the tested-substance, CT has the better using foreground..

在混凝土结构的施工及使用过程中，由于受其自身及外界各种因素的影响，常常会产生一些缺陷，对结构物的承载能力和耐久性造成严重影响，采用无损检测技术进行质量检测和健康诊断，这对混凝土结构开展安全、稳定性评估以及病害隐患治理研究具有重要意义。本论文主要针对大体积混凝土结构缺陷的检测方法展开研究工作，重点讨论了超声波法检测混凝土结构裂缝的基本原理和方法及其特点、适用范围，运用动力有限元数值模拟其检测过程，探讨了有裂缝缺陷的混凝土结构在脉冲荷载作用下弹性波的传播及其变化特征，研究了不同裂缝深度下首波相位变化规律，得出了反转临界点与裂缝深度之间的关系，这对实际工程应用具有指导意义。声波CT是一种新的无损检测技术，它是利用声波穿透被检测体获取声波接收时间，来进行计算机反演成像的技术。本文利用直射线法编制了层析成像程序，能较好地呈现被检测物体各微小单元的声波速度分布图像，从而对检测体的质量状况作出诊断评估，具有较好的应用发展前景。

The experimental result reveals the dynamic details of the molecular beam moving in the background gas, especially the effects on the background molecules.

实验结果揭示了分子束在背景气体中运动的动力学详细状况，尤其是其对背景分子速度分布的影响。

In order to calculate the helicopter hover ceiling in OGE precisely, some aerodynamic parametem, such as tip loss effect, induced velocity distribution, the effect of rotor downwash on the fuselage and power transfer of engine into rotor, must be treated carefully.

准确计算直升机的悬停升限依赖于诸如桨尖损失系数，非均匀旋翼诱导速度分布，旋翼下洗引起的直升机增重效应及发动机与旋翼之间的功率传递系数等气动参数的准确度。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。