查询词典 surface

A deformable model is used to reconstruct the shape of the LV: first, the dynamic equation governing the surface deformation is deduced; secondly the image planes are mapped to the reconstruction coordinate system. From the slices data, the external force exerted on the surface is defined and the elastic force of the surface is constructed by mean curvature of the deformation surface. Finally, a level set method is applied to solve the dynamic equation for LV shape.

为了重建左心室的形状，使用基於形变模型的方法：首先建立变形曲面的动力学方程；再将成像坐标系中的图像平面映射到重建坐标系，根据图像数据构造外力，使用平均曲率构造变形曲面的弹性力，然后用水平集数值解法求解动力学方程以重建左心室的表面。

We expect it will benefit the industry field to break through the optical measuring limits at present by offering some new ideas. Optical measuring research based on moire interferometry has developed for several decades. The main idea of this research is to utilize the moire effect caused by two superimposed gratings of identical or similar spatial frequency. One is the reference grating and it is a virtual grating created by a computer program in this research; The other grating is the image of grating projected on the measured surface by the DLP projector, and this grating will distort because of the different sloped profile of the surface. To superimpose the program-created grating and the captured distorted grating will derive the so-called moire effect. This research combined the basic theory of optical interferometry and moire effect to project the different phases of the projected grating fringes by the phase-shifting method and compute the principal value of arguments between -π,π. In the end, the phase unwrapping program based on discrete Fourier transform of solving PDEs is used to unwrap the phase of the measured surface, and finally the surface profile is derived by the optical measuring system.

以叠纹干涉术为基础的光学检测研究之发展早已行之有年，而在本研究中所采用的投影叠纹法(Projection moiré)之主要精神在於藉由两道空间频率相近或相同的光栅相互叠加而成的效应，其中一道为参考光栅，而本研究中的参考光栅是以程式产生可调整不同空间频率的虚拟光栅；另一道则为投影至待测物表面的光栅影像，而在起伏高度不一的待测表面上的光栅影像会受到待测物表面起伏状况不同而在观测方向产生光栅投影条纹影像的歪曲变形，将电脑产生的参考光栅与由影像撷取装置所获取投影於待测物表面的光栅影像作叠合，便会产生所谓的叠纹效应；利用基本的光学干涉理论与叠纹效应结合，本研究中以相移法来改变投影於待测表面的光栅相位，再以相移法的理论反运算出在带有待测面各点高度资讯之介於-π，π相位主幅角，再以离散傅立叶转换解偏微分方程的相位重建程式还原待测面的相位值，以得知待测面之表面轮廓。

The topographical parameters have been analyzed by taking into account the thermal effect during the friction process. As the results, three kinds of typical topographical features have been observed for the worn surfaces of C G iron with various P content. Namely, C G iron with 0.05% P, 1.30% P, and 0.70% P show worn surfaces characterized by groove ridge, peak pits and their combined topography. The C G iron specimen with peak pits type worn surface topography showes the lowest wear rate and highest friction coefficient, while that with groove ridge type worn surface topography shows the highest wear rate and lowest friction coefficient. The groove ridge type worn surface has a relatively large value of surface height deviation and void volume ratio and negative large value of skewness, which is contrary to the peak pits topography.

结果表明：度销磨损表面主要呈现犁沟型、孤岛型及二者的混合型3种形貌特征，其中具有孤岛型磨损表面形貌特征的试样的摩擦系数较高，磨损率较低；而具有犁沟型磨损表面形貌特征的试样的摩擦系数最低，磨损率最高，分析表面形貌参数发现：犁沟型表面形貌具有最大的表面高度偏差和表面空隙率及高负值的表面高度分布参数；而孤岛型表面形貌的表面高度偏差和表面空隙率最小，表面高度分布参数为高正值。

Substitute surface conception was introduced in the tolerance modeling. Intrinsic deviation between the substitute surface and the theoretical surface was described by vector function on the basis of the vector parametric representation of the theoretical surface.

引入替代表面的概念，基于理论表面矢量参数化表示，用矢函数来描述替代表面和理论表面之间的本质特征偏差。

Therefore, comparing with the traditional CAD system adopting the method of manual entirely for creating the addendum surface and the binder surface, the parametric design of the addendum surface and the binder surface has become the trend for its high efficiency and convenience of modification.

因而，相对于传统的CAD系统采用全手动方式来生成工艺补充部分的方法，工艺补充部分的参数化设计以其时间上的高效率和修改的方便性成为发展的趋势。

On the basis of pollen analysis of surface sample in North China, polynomial function analysis method was applied to establish pollen climate response surface of Pinus, Betula, Quercus, Artemisia, Chenopodiaceae, Compositae, Picea, Ephedra, Gramineae in North China, therefore an easy and applicable method for reconstructing palaeoclimate and palaeoenvironment with data of fossil pollen was founded; Multi-analysis method was applied to analyse the principal elements of surface sample pollen in central Inner Mongolia Steppe, the assemblages of surface sample pollen in steppe area and its relationship with vegetation type were discussed with helps from spore-pollen analysis of a peat section in Chasuqi, Inner Mongolia and 〓C chronometer, fossil pollen data were obtained with high resolution on the peat section in Chasuqi. Vegetation succession and environmental changes since Holocene at resolution of 70 years were primarily reconstructed in south Mount Daqingshan and Plain Tumete. The changes in the area were copmared with those in the neighbouring areas during the same period. It was found that Holocene environmental change had undergone the following stages: cold-arid, temperate-wet, warm-wet, temperate-arid and cold-arid, and the climatical optimum period occurred in 5000-4100 aB.

本文在对中国北方表土花粉研究的基础上，采用多项式函数回归方法建造了中国北方松属、桦属、栎属、蒿属、藜科、菊科、云杉属、麻黄属、禾本科等的花粉——气候趋势面，从而为利用化石花粉资料直接恢复古气候、古环境提供了一种方便易行的方法；采用多元分析方法对内蒙古中部草原区表土花粉进行了主成分分析，探讨了草原区表土花粉组合的规律及与植被类型的关系；本文还应用孢粉分析方法，结合〓C测年技术，通过内蒙古中部察素齐泥炭剖面高分辨率的化石花粉数据，初步恢复了大青山山地南部及土默特平原地区分辨率为70年的全新世以来植被演替和环境变迁的状况，并与邻近地区的全新世古气候、古环境进行了对比研究，研究发现，本区域全新世古环境的变迁序列基本上可以与周围地区及华北地区进行对比，其环境变迁经历了凉干～温湿～暖湿～温干～凉干的变化，且气候最适宜期出现在5000～4100aB.P。

To decompose prismoid subject into sweepable sub-volumes, the source vertices project into target surface and decompose target surface to many subdomains. The virtual surfaces are found by linking opposite vertices from source surface and target surface, finally cut volume to sub-volumes. It is also designed spheriform decomposition based on geometry character.

虚拟分解主要是通过将棱柱体的源曲面边界顶点映射到目标曲面，将目标曲面划分成和源曲面一一对应的区域，连接对应的顶点建立虚拟剖分曲面，利用虚拟曲面将复杂的几何体剖分成子几何体。

Firstly, using quadric surface to fit with given surface and calculate the error metric to identify free surface and general quadric surface.

首先用一般二次曲面方程拟合测量数据并计算曲面的拟合误差，比较拟合误差与阈值的大小来识别自由曲面和一般二次曲面。

Generally the surface of objects such as mechanical parts is mainly composed of quadric surface, free-form surface and blending surface, which are defined as features in this paper.

实物产品尤其是机械零件的表面通常是由一些可以称为特征的几何曲面组成，这些几何特征曲面主要包括二次曲面、自由曲面和过渡曲面等。

The gel dynamics experiments showed that the gel formation law was similar with the other polymer systems, which wasrelated with dense surface under the soft coagulating condition and the thickening gel; the square of gel thickness was linear with coagulation time. The qualitative analysis of the surface puckers of fibers spun from wet spinning and dry-jet wet spinning was made. The positions where the die swell appeared were not the same and the die swell appeared at the air gap where the fiber would markedly been elongated and vary little in the coagulant, thus the surface of fiber spun from dry-jet wet spinning was more smooth. The radial component concentration gradient was responsible for the radial structure of PAN fiber spun from dry-jet wet spinning. The thicker surface with microvoid structure of

对湿纺和干湿纺进行比较表层沟槽的产生进行定性分析，原因在于孔口胀大区域出现在不同位置，在干湿纺中，溶液的孔口胀大出现在空气层，并在该区完成大部分形变，进入凝固浴后形变很小，纤维表面较为光滑；干湿纺PAN纤维径向结构存在差异，这与丝条内组分由于双扩散进行导致径向上存在浓度差异直接相关；凝固强度较大的体系，可以获得厚度较大且孔结构尺寸较小的皮层；含较少缠结的PAN原液在纤维成形后截面很圆整，但原液缠结浓度增大时成形后圆整度下降；PAN纤维成形是一个远离平衡的过程，凝固作用缓和的体系可以使成形过程靠近平衡，可获得更大尺寸的孔洞结构；原液中少量的非溶剂添加剂显著改变纤维径向结构，可获得孔洞尺寸更小和更为均一的径向结构，这与径向浓度差异的减小、分相时间的集中相关；PAN原液的成形纤维表面依赖于凝固强度；由AFM对相近凝固条件下成形的PAN膜进下

Chrysanthemum of 10 thousand birthday is lax to edaphic requirement, with the arenaceous qualitative loam with fecund, good drainage had better.

万寿菊对土壤要求不严，以肥沃。排水良好的砂质壤土为好。

He unstepped the mast and furled the sail and tied it.

他拔下桅杆，把帆卷起，系住。