查询词典 orientable surface
- 与 orientable surface 相关的网络例句 [注：此内容来源于网络，仅供参考]
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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。
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Theorem Let M be a orientable or non-orientable closed surface, and f a C°-flow whose every singular point is isolated. Then f has POTP if and only if the following three conditions hold
定理 设M是任一个可定向或不可定向的闭曲面，f是M上任一个奇点均孤点的C〓-流，则f具有伪轨跟踪性质的充分必要条件是
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Using combinatorial thoughts and topological methods,a closed curve system that contains the most number of non-contractible,pair-wise disjoint and pair-wise non-homotopic closed curves on the orientable surface is investigated.
利用组合数学的思想、拓扑的方法研究在可定向曲面上，一类含有个数最多的不可收缩的、两两不相交、互不同伦的圈系统及其性质，得出了关于这些圈的一些拓扑定性性质，并给出这些圈在曲面上的位置分布。
- 推荐网络例句
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It is also known as one of the most poisonous naturally occurring substances.
它也被称为一个最自然发生的有毒物质。
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The greatest stress is found at the location on the cross section where V is the largest.
最大应力出现在横截面上V为最大的地方。
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It is the most important three water problem which our country faces in the 21st century that flood and waterlog, drought and shortage of water, the deterioration of water environment.
洪涝灾害、干旱缺水、水环境恶化是二十一世纪我国面临的三大水问题。