157Tm原子核三轴超形变的研究

根据TRS理论计算了^157Tm核的位能面，并预言了其三轴超形变的存在,计算的结果与文献上的结果符合得较好。     

Designing Bézier surfaces minimizing the L~2-norm of the Gaussian curvature

INTRODUCTION Struik (1988) stated that the Gaussian curvatureof a developable surface is zero, and vice versa. If apiecewise smooth closed curve is given as a boundarycurve, there is not always a regular developable sur-face interpolating the boundary in theory, as DoCarmo (1976) proposed. There is still not a simpleand effective method for constructing a developablesurface in Computer Graphics (CG) and ComputerAided Geometric Design (CAGD). But, a Béziersurface which has a minimu…     

On the Ruled surfaces in Minkowski 3-space R1^3

INTRODUCTIONLet ú3={(x1,x2,x3)|x1,x2,x3∈ú} be a 3D vector space, x=(x1,x2,x3) and y=(y1,y2,y3) be two vectors in ú3. The pseudo scalar product of x and y is defined by     

A level set based segmentation approach for point-sampled surfaces

Segmenting a complex 3D surface model into some visually meaningful sub-parts is one of the fundamental problems in digital geometry processing. In this paper, a novel segmentation approach of point-sampled surfaces is proposed, which is based on the level set evolution scheme. To segment the model so as to align the patch boundaries with high curvature zones, the driven speed function for the zero level set inside narrow band is defined by the extended curvature field, which approaches zero speed as the propagating front approaches high curvature zone. The effectiveness of the proposed approach is demonstrated by our ex- perimental results. Furthermore, two applications of model segmentation are illustrated, such as piecewise parameterization and local editing for point-sampled geometry.     

双三次B样条曲面的生成方法

样条曲面是CAD、CAM中常用的曲面,从三维空间坐标变换、双三次B样条曲面的消隐及显示等两个方面讨论了双三次B样条曲面的一种生成方法.     

三个不等半径圆角曲面熔接及处理

以某零件一角为例,利用MasterCAM的CAD功能,介绍了熔接及处理三个不等半径圆角曲面的两种方法,方法一采用直观传统的三圆角曲面熔接的命令进行处理;方法二采用两曲面熔接命令.重点阐述了圆角熔接的比较,用理论证明了采用两曲面熔接命令处理三个不等半径圆角曲面的方法优于直接采用三圆角曲面熔接的命令.     

矩形域上Bézier曲面片的凸性

根据Gauss曲率的符号,讨论了矩形域上B啨zier曲面片的凸性,得出用B啨zier点表示的凸性条件     

钢桥面硬沥青浇注式沥青混合料低温性能研究

通过汉堡轮辙试验 ,考察了浇注式沥青混合料的抗车辙能力 ,硬沥青浇注式沥青混合料具有良好的抗车辙能力 .通过低温弯曲试验和逐步降温的钢桥面铺装复合结构疲劳试验 ,测试与比较了使用硬沥青的浇注式混合料低温抗裂性能 .高性能聚合物改性沥青浇注式混合料具有较长的疲劳寿命和较低的断裂温度 ,可用于钢桥面浇注式沥青铺装 .     

CPn中的齐次曲面

从齐性曲面的等距群出发,讨论CPn中的齐性曲面,得到了CPn中等距群为2维的齐性曲面的分类,并且用李群与活动标价相结合的方法给出了CP2中齐性曲面的分类定理的证明。     

二面角问题的解题方法探讨

本文根据立体几何中二面角的特点 ,介绍了四种二面角问题的解题方法