有理曲线

We shall first apply the technique ofμ-bases and local cohomology to study the minimal generators for the moving surface ideals of rational cubic space curves and rational quartic space curves,and then study the implicit equations of rational space curves under different definitions of implicit equations.

在第五章中，我们将同调代数理论与μ基理论相结合，详细分析三次及四次空间有理曲线的动曲面理想生成元，为一般空间有理曲线的动曲面理想生成元的(来源：A21B12ceC论文网www.abclunwen.com)研究开辟可能的道路。

The close relationship between the Hybrid polynomial approximation and the classical Hermite polynomial approximation to rational curves and surfaces are studied, Hermite approximation is in fact a special case of Hybrid approximation. The sufficient and necessary condition for the convergence of Hybrid approximation to rational Bézier surface is deduced and proved.

围绕着有理曲线曲面的Hybrid逼近，作者研究了有理曲线曲面的Hybrid多项式逼近与传统的Hermite多项式逼近之间的密切关系，并指出Hermite逼近事实上是Hybrid逼近的一种特例，此后演绎并证明了有理Bézier曲面的Hybrid多项式逼近收敛的充分必要条件。

The constructions of rational curves depend on the pencil of lines which may be blended in two or more straight lines.

有理曲线由直线束确定，直线束由两个或多个直线经调配得出。

In the third chapter, interval polynomial approximation of rational curves is introduced.

第三章主要介绍了有理曲线的区间多项式逼近。

However, due to the complex of computation and the need of the design, sometime we need to use polynomial approximation for a rational curves and surfaces.

然而由于计算的复杂性和设计的需要，有时我们还需要用多项式函数来逼近有理曲线和曲面。

In this paper, we survey the development of polynomial approximation of rational curves and state the knowledge of interval curves in the first chapter.

本论文中，第一章首先介绍了有理曲线曲面的多项式逼近研究工作的发展情况和区间曲线曲面一些相关知识。

Especially, an explicit representation of quintic PB curves is established and the sufficient and necessary algebraic characterization of quintic PB curves is presented.

对于n次PB曲线，得到了以(2n-1)次有理曲线精确表示的等距线和多项式形式的弧长表达式。

Rational planar curve; rational space curve; rational ruled surface; moving curve/surface;μ-bases; singularity; self-intersection curve; moving curve/moving surface ideal; ideal-theoretic/set-theoretic generators

基础科学，数学，几何、拓扑平面有理曲线；空间有理曲线；有理直纹面；动曲线/曲面；μ基；奇点；自交线；动曲线/动曲面理想；集论/理想论生成元

We shall explore the theory and computational methods of the singularities of rational planar curves and rational space curves fromμ-bases.

本文中我们将首先讨论基于μ基的平面有理曲线与空间有理曲线奇点的理论及计算。特别地。对平面有理曲线。

ABSTRACT This paper summarizes our researches on two key techniques in curve and surface modeling-the geometric approximation techniques and the geometric interpolation techniques. The former includes three types of geometric approximation techniques: Hybrid polynomial approximation to rational curves and surfaces, offset curves and surfaces approximation, interval Bézier curves and surfaces approximation. The latter includes a series of algorithms for shape blending modeling: the MSI algorithm for shape blending between space polylines or trees, the MSI algorithm for shape blending between triangular meshes, and skeleton-based shape blending algorithms using triangular decomposition and star-shape decomposition.

本文是作者对曲线曲面造型中两类核心技术几何逼近技术和几何插值技术的研究成果的总结，其中前者包括有理曲线曲面的Hybrid多项式逼近、等距曲线曲面逼近和区间曲线曲面逼近等三类几何逼近方法；后者包括用于形状混合造型的几何插值方法的一系列算法：空间多边形形状混合的MSI插值算法、三角网格形状混合的MSI插值算法、树的形状混合的MSI插值算法以及基于骨架树形状混合的三角剖分算法和星形剖分算法。

The absorption and distribution of chromium were studied in ryeusing nutrient culture technique and pot experiment.

采用不同浓度K2CrO4(0，0.4，0.8和1.2 mmol/L)的Hoagland营养液处理黑麦幼苗，测定铬在黑麦体内的亚细胞分布、铬化学形态及不同部位的积累。

By analyzing theory foundation of mathematical morphology in the digital image processing, researching morphology arithmetic of the binary Image, discussing two basic forms for the least structure element: dilation and erosion.

通过分析数学形态学在图像中的理论基础，研究二值图像的形态分析算法，探讨最小结构元素的两种基本形态：膨胀和腐蚀；分析了数学形态学复杂算法的基本原理，把数学形态学的部分并行处理理念引入到家实际应用中。