边界条件

The distributions of velocity, velocity gradient, shear stress, clongation stress, first normal stress difference and pressure of the flow of a power-law fluid in the profile die were analyzed. It indicates that for a power-law fluid only after a few iterations a good convergence can be reached, even though in the case of high extrusion velocity.

详细分析了聚合物口模挤出三维计算机模拟研究中的若干关键技术问题，如对异型材结构特点的分析、边界条件的确定、初始速度场的自动生成、罚数的求取、粘弹性流动模拟中的高We数问题、三维挤出胀大的自由界面更新等。

The rock composition, material disperse, structure characteristic, boundary condi tion, movement mode and forming mechanism of plane rotation slope are completely differ nt from the slope deformation and destroy people usually thought, which moves frorn top to bottom, callapsing or ratating vertical around horizontal axis under the outside load tak ing gravitational force as primaty factor.

平面旋转坡体的岩性组成、物质分布、结构特征、边界条件、运动方式及形成机理等与过去人们习惯上认识的那种在以重力为主的外荷作用下，自上而下同步位移、崩落或绕水平轴的立面旋转坡体的破坏类型完全不同。

The 3-D single phase simulation using CFX for the rod bundle channnel was going on by choosing the reasonable mathematical and physical models and boundary conditions. After a lot of numerical calculations, the sensitivity of gemotery was validated. The flow and heat transfer characteristics for several typical velocities were numerically analyzed and visually showed. The results show that the CFX simulation can be used for designing and optimizing fuel assembly in reactor engineering.

通过选定合理的数学、物理模型和边界条件，采用通用CFD程序ANSYS CFX 10.0对带有AGA-2G定位格架的5×5棒束通道流场进行了三维单相数值模拟，经过大量计算，验证了厚度、刚突等几何敏感性，得到了带定位格架棒束通道内的速度、压力和温度分布，分析了定位格架对流场、温度场的影响，直观地获得了搅混叶片的搅混效果，并将结果同实验值进行了初步比较。

The formulae were determined to calculate the convection boundary condition of the gas shielded arc welding with forced convection.

确定了适用于有强制对流效果的气体保护焊的对流边界条件计算公式。

Based on Darcy's law, the depth distribution of the stability zone and the deposits zone of gas hydrate is quantified, and the effective factors of their boundary conditions are identified carefully with the theoretical model.

本文以达西定律为基础，通过理论模型对水合物稳定区、沉积区的深度分布进行了量化并对各自的边界条件的影响因素做了详细的分析。

A rib heat transfer model is then used to calculate the equivalent heat transfer coefficient of the blade passa...

在汽轮机转子的温度场与热应力场有限元分析中，该计算方法为确定叶轮轮缘的传热边界条件提供了依据。

The influences of combustion boundary conditions on ethanol homogeneous charge compression ignition combustion were investigated.

在一台由CA6110柴油机改造而成的单缸发动机上进行了燃烧边界条件对乙醇燃料均质压燃燃烧过程影响的试验研究。

Combined with the boundary conditions of soil surface under unit impulse excitation,the Green's functions for ground displacements in wavenumber-frequency domain are deduced.The Green's functions obtained are implemented by MATLAB,and their preliminary characteristics are presented via an example.

结合单位脉冲荷载作用下地基土表面的边界条件，推导出波数-频率域内地基土表面位移Green函数的解析解，用Matlab程序语言对理论进行实现并通过算例对地基土表面位移Green函数的特征进行了分析和总结。

They are the carry-over of the streams, the sediment releasing and the carry-over of the water from Qiantang River. Estimated the total phosphorus data of them as the boundary condition in calculating, Then according to the actual water diversion and water distribution of the West Lake of the four seasons in 2004, the source of total phosphorus and the data of the 11 concentration field measuring point, inversion analysis was carried out, then the comprehensive sedimentation constant k was obtained.

以总磷为模拟指标建立了水质模型，在入湖总磷负荷来源分析及测算的基础上，确定了西湖总磷的主要来源为入湖溪流携带、西湖底泥释磷、钱塘江引水携带，并测算了具体的数值作为浓度场计算的边界条件。

In the process of impact of abrasive jet on rock, resulting dynamic stress plays an important role in rock destruction. The stress wave resulted makes local rock tensile and shearing, then makes rock destructed. In the conditions of some hypotheses, the mechanical model that rock is applied by stress wave, i.e. jet wave basic equations, are set up by wave theory, and the formula of the maximum normal stress resulted by stress wave is deduced according to known boundary conditions.

描述了岩石材料在磨料射流的冲击下破坏的主要原因，分析了应力波就是岩石局部受到拉伸和剪切并最终使岩石发生破坏的根本因素，在这一假设的前提下采用波动理论建立了岩石受应力波作用的力学模型即射流波动的基本方程，在已知的边界条件下推导出了由波动引起的最大正应力的计算公式。

Cynanchum Lingtai apricot production in the average weight 65 grams, the brightly-colored fruit, juicy rich, sweet-sour taste, sweet from the nucleolus, when the late Qing Dynasty famous Shaanxi, Gansu provinces, the Qing imperial court Tongzhi tribute for years.

灵台生产的牛心杏平均单果重65克，果实色泽鲜艳，汁多味浓，甜酸适口，离核仁甜，清末时就驰名陕、甘两省，清同治年间曾为朝廷贡品。

Chenopodium album,Solanum nigrum, and Amaranthus retroflexus were very susceptible to the herbicides. Polygonum persicaria and Abutilon theophrasti were relatively less susceptible to the herbicides, and Lycopersicon esculentum was not susceptible to it. The relationship between reduction rates of weed biomass and PPM values of weed leaves 2,4, and 6 days after treatment was established.

供试的6种杂草对该混剂的敏感性存在显著差异：红心藜Chenopodium album、龙葵Solanum nigrum和反枝苋Amaranthus retroflexus对该混剂最敏感，ED90值分别为47.65、71.67和29.17g/hm2；春蓼Polygonum persicaria和苘麻Abutilon theophrasti敏感，ED90值分别为96.91、114.20g/hm2；而番茄不敏感。