体元

The values of joint geometric characters and number of random joints in each group are decided through the derivable formulas.

其次，利用裂隙介质的渗透张量理论计算不同尺寸的岩体渗透张量，进而确定节理岩体的表征体元。

Numerical experiments show that, with increasing the number of unit cell, n, the results got from RVE method under the Dirichlet and Neumann boundary conditions converge towards those the obtained by the homogenization method from the upper and lower sides respectively.

数值结果表明，Dirichlet型和Neumann型边界条件下的代表体元法所得结果随着参与模拟的单胞个数的增加，分别从上下界逼近均匀化方法的结果。

First, we extract the boundaries between two different materials by weighting with gray-level gradient,and only voxels on these boundaries participate in the generation of each image, so it drastically reduces the rendering time. Second. We think the voxels on boundaries as the mixture of different materials,so in every voxel there is a surface. We use the oriented cube-interpolation technique to get the intersection point of viewing orientation and the surface in the voxel, then compute the surface normal of the intersection point. We use the normal to shade the voxel in order to improve the image quality.

首先，采用灰度梯度加权提取出三维数据场中不同物质间的边界，根据显示的需要只对这些边界上的体元赋予相应的阻光度并进行光亮度合成计算，因而可大大减少计算量，提高显示的速度；将边界上的体元作为不同物质的混合体，采用与方向有关的三线性插值来计算视线方向与体素内等值面的交点，根据交点的法向量进行光照效应计算以提高显示图像的质量；最后用投影成像法显示最终的图像。

By analyzing the problem of hydrological 3D spatial dispersion in 3D finite differential numeric simulation of porous groundwater flow, as well as discontinuous spatial distribution and asymmetric thickness of porous aquiferous strata and partitive groundwater stratum, the paper presents the GIS-based technique of 3D spatial dispersion of porous aquiferous stratum system. Besides, the paper puts forward the 3D spatial dispersion method of irregular hexahedral unit based on GIS to guarantee to the greatest degree the uniqueness of the stratum types among the dispersed units and improve the precision of 3D spatial dispersion.

分析了目前孔隙地下水流三维有限差分数值模拟中对含水层系统三维空间离散存在的问题，针对自然界孔隙含水层与隔水层空间分布的不连续性与厚度的不均匀性，研究了基於GIS的孔隙含水层系统三维空间离散实现的技术路线，提出了基於GIS与不规则六面体元的孔隙含水层系统的三维空间离散方法，最大限度地保证了离散体元中含水层类型的单一性，提高了孔隙地下水流模拟模型三维空间离散的精度。

By analyzing the problem of hydrological 3D spatial dispersion in 3D finite differential numeric simulation of porous groundwater flow, as well as discontinuous spatial distribution and asymmetric thickness of porous aquiferous strata and partitive groundwater stratum, the paper presents the GIS-based technique of 3D spatial dispersion of porous aquiferous stratum system .

分析了目前孔隙地下水流三维有限差分数值模拟中对含水层系统三维空间离散存在的问题，针对自然界孔隙含水层与隔水层空间分布的不连续性与厚度的不均匀性，研究了基于GIS的孔隙含水层系统三维空间离散实现的技术路线，提出了基于GIS与不规则六面体元的孔隙含水层系统的三维空间离散方法，最大限度地保证了离散体元中含水层类型的单一性，提高了孔隙地下水流模拟模型三维空间离散的精度。

This paper studies the reconstruction of the 3D solidi model based on ICT slicing and presents a new edge matching method and a reconstruction method of solid-model based on surface identification, Volume cell construction and volume mergence.

研究了基于工业CT 切片图形的实体模型三维重构技术，讨论了边界配准技术，提出了基于表面识别、通过逐层体元构造和体元粘合来构造实体几何模型的重建思想，并给出了一个成功的重构实

Here Erosion Voxel has explicit geographical meaning because it reflects corresponding mean surface soil erosion volume of each pixel in a unit time interval; at the same time it is combined with metabal1 technology.

侵蚀体元在这里具有明确的地理意义，因为它反映单位时间段每个像元所对应的地表平均土壤侵蚀体积，同时融入元球绘制技术。

We can compute three dimensionalvelocity distribution on a planar domain of flow field based on conventional ParticleImage Velocimetryand 3D reconstruction theory of stereophotogrammetry.

在流场空间两个不完全交叠的体积元(映射为两个摄影机象平面上以同名点为中心的两个相同大小的判读小区域)中的示踪粒子的统计性质都能同样表征这两个体积元公共中心的流体运动的假设下，PIV技术与体视三维重建理论的结合，可以将原PIV技术中二维统计平均的概念扩展为三维统计平均，并且在确定体积元公共中心位置之后，直接实现空间流体体元的三维位移重建。

The Far Voxels [10] system, for instance, exploits the programmability and batched rendering performance of current GPUs, and is based on the idea of moving the grain of the multi-resolution surface model up from points or triangles to small volumetric clusters, which represent spatially localized dataset regions using groups of graphics primitives.

Far系统，充分利用了当前GPU的可编程能力与批处理能力，基于的思想是将表面模型的多分辨率的粒度从点或三角形转移到小的体簇，这些体元是使用空间区域的一组图元进行表达的。

An optimum design for the complex body formed together with the volute casing, base ring and cement foundation of a hydraulic turbine is made by the gradient method and a program is developed on the basis of finite element analysis with the plane and shell element, body element, boundary element and pseudo element.

本文对由水轮机蜗壳、座环和水泥基础所构成的复杂组合体，在采用板壳元、块体元、边界元和伪单元等四类单元进行有限元分析的基础上，选用最速下降法研究了优化设计过程，并编制成程序系统。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。