三角

In this paper, firstly, the embeddability of near-triangular graphs on the orientable surface is studied. By using Petersen's Theorem about 1-factor, we first prove that for a near-triangulation on the orientable surface, its geometry dual graph has a 1-factor; then after a procedure of operation leaded by the 1-factor, we show that if a graph G triangulates some orientable surface S_g, then G has a near-triangular embedding in S_h for h = g,g + 1,...,β(G/2」, where β is the Betti number of G. Hence we obtain a conclusion: A near-triangulation of the orientable surface is upper-embeddable. As a generalization, a class of near-quadrangulation is studied, and similar results are obtained.

本文首先研究了近三角剖分图的可定向曲面嵌入性质，通过运用Petersen关于1-因子的定理，首先证明了对于可定向曲面上的三角剖分图，其几何对偶图具有1-因子；然后在1-因子的导向下，通过做一系列增加亏格的手术，证明了如果一个图G三角剖分可定向曲面S_g，那么G可以近三角剖分可定向曲面S_h，这里h=g，g+1，…，「β(G／2」，β是指图G的Betti数，从而得出推论：可定向曲面上的三角剖分图是上可嵌入的，作为推广，又研究了一类近四角剖分图的可定向曲面嵌入性质，并得到类似的结论。

In chapter 4, an optimization Boolean operator of triangular mesh and the algorithm of adding point-swapping edge locally are put forward. With boundary traced by adding midpoint, the triangulation of 2D arbitrary domain is realized. The fast searching method which combines the index rectangle with compass based normal vector is designed to speed the triangulation algorithm.

第四章提出了一种优化的三角网格布尔运算和逐点加入—局部换边法，用中点加点法恢复边界，实现了二维任意域Delaunay三角化算法，用索引矩形和基于法矢的指南针法相结合的快速查询法有效地提高了三角化算法的速度，给出了二维任意域三角网格剖分的实例。

Whether Zhou s triangulation would derive MWT of a planar point set, Zhou Peide had drawn a new conclusion before the comments "Zhou s Triangulation is not the minimum weight triangulation " were given.

周培德三角剖分是否能得到最小权三角剖分，周培德在《周培德三角部分不是最小权三角剖分》一文撰写之前已有新的结论，本文还指出《周培德三角剖分不是最小权三角部分》一文所举反例不成

Based on the study of triangle mesh of creation algorithm, include the arithmetic of regular data make triangle mesh and irregular data make triangle mash. The paper put forward a optimized triangle mesh algorithm. Its key point is divide data into pieces in advance, then set up the net. The experiment result shows that this algorithm improves not only the efficiency of terrain molding, but also the precision compared with the old algorithms The main purposes of this paper are research visualization algorithm of three dimensions and the arithmetic of terrain visualization.

本文研究了基于三角形网格的地形建模的基本理论和方法，包括规则数据的三角网生成以及不规则三角网 TIN 的生成算法，总结了前人在这些方面所做的工作，本文提出了一种优化的三角网格生成算法，实验结果表明，该算法不仅提高了地形建模的效率，而且所生成的三角网格模型与以往算法相比精确性也有很大的提高。

Two above methods are generalized to tensor product Bézier surfaces and triangular Bézier surfaces, we give two approaches of degree reduction for tensor product Bézier surfaces, each of which reduces a given degree n×m tensor product Bézier surface to a n〓×m〓 one, and two methods of degree reduction for triangular Bézier surfaces, which reduce a given degree n triangular Bézier surface to a degree m one. The explicit formulas of control points for reduced tensor product and triangular Bézier surfaces are obtained respectively.

张量积Bézier曲面的两种降阶方法均可把n×m阶张量积Bézier曲面一次降阶为n〓×m〓阶张量积Bézier曲面；三角Bézier曲面的两种降阶方法均可把n阶三角Bézier曲面一次降阶为m阶三角Bézier曲面，并给出降阶张量积Bézier曲面和降阶三角Bézier曲面控制顶点的显示表示式。

Long triangle already was long triangle of China not only, also be the long triangle of the world, long three-cornered development should be put in global pattern to consider.

长三角已不仅是中国的长三角，也是世界的长三角，长三角的发展要放在全球的格局中来考虑。

The concept of triangular ratio and triangle formula;(2) Reorganization and deep understanding of the concept of complex number which are promoted by the learning of triangular representation of complex number;(3) Teacher's beliefs and college entrance examination.

本文中的调查显示，复数的三角形式是学生认知的难点，我从以下四点分析了对学生学习三角形式的影响：（1）三角比、三角公式对复数三角形式认知的影响；（2）复数三角形式的学习是学生对复数认知的重组和深化；（3）老师的信念和高考对学生学习复数三角形式的影响；（4）教材体系的编排对学生学习复数三角形式的影响。

Results There were Parkinson trigone, paramedical trigone, Mullan trigone, lateral trigone, Glasscock trigone and Kawase trigone which were exposed in the lateral wall and their surrounding areas.

结果海绵窦外侧壁及其附近的旁内侧三角、Parkinson三角、Mullan三角、外侧三角、Glasscock三角和Kawase三角，这些三角均可以从硬膜外得以暴露。

Results:12 trigones were observed in CS.They were anteromedial trigone,medial trigone,carotid trigone and oculomotor trigone in the superior wall of the CS; Lateromedial trigone,Parkinson trigone,Mullan trigone,lateral trigone,Glasscock trigone and Kawase trigone in/near the lateral wall.Inferolateral trigone and inferomedial trigone in the posterior wall.

结果：CS上壁内有前内侧三角、内侧三角、颈动脉三角和动眼三角；外壁内及其附近有旁内侧三角、Parkinson三角、Mullan三角、外侧三角、Glasscock三角和Kawase三角：后壁上有下外侧三角和下内侧三角。

The P wave duration and P 2R interval were increased while pacing at right atrial appendage 1 The activation time from pacing site to His bundle and coronary sinus was the longest in pacing at right atrial appendage , while the activation time in pacing at Koch triangle , Koch triangle with high right atrium and biatria was significantly shorter especially pacing at Koch triangle and Koch triangle with high right atrium1 There were no significant differences in right atrium pressure among all pacings1 Conclusion It is suggested that Koch triangle pacing could probably replace high right atrial with coronary sinus pacing and biatrial pacing 1

从心房激动顺序分析，右心耳起搏时，激动传至希氏束区及冠状窦区的时间最长，而 Koch三角、Koch三角+高位右房及双房起搏时则较短，尤其是 Koch三角、Koch三角+高位右房起搏缩短更明显。另外，不同部位、不同方式起搏时右心房压力无差异。结论 Koch三角起搏在某种程度上可替代高位右房+冠状窦起搏及双房起搏。

I didn't watch TV last night, because it .

昨晚我没有看电视，因为电视机坏了。

Since this year, in a lot of villages of Beijing, TV of elevator liquid crystal was removed.

今年以来，在北京的很多小区里，电梯液晶电视被撤了下来。