拓扑圆

This article focuses on the line-line, line-region and region-region topological relations algorithm, which come down to the same question: whether there are intersections between line and line. The sweep-line algorithm was studied by many people, but has some deficiencies to be improved, in order to handle some special cases and increase program efficiency. My works as follows: rectangular envelope to reduce executive times , vector cross multiplication to determine intersection between line and line, coordinates and slope method to deal with some special cases. C program examples are showed together.(5) Finally, to prove capability and efficiency of the model and calculation method, some test systems are developed. For example, complex spatial topological relation query, parcels' exact area with the area of linear object reduced in land use, quality inspection to cadastral data according to topological rule, spatio-temporal change query of cadastral data.

将线线、线面、面面之间的拓扑关系实现的算法归结为线与线之间求交的基本问题；为处理一些特殊的拓扑关系情况，提高扫描线算法的效率，探讨了包络矩形粗滤、判断线线是否相交的矢量叉乘法、线节点重合或共线的斜率坐标判断法等改进方法；同时还设计了一种新的节点微小圆求交的算法，可应用于图斑与线状地物细分拓扑关系及地类面积的计算；（5）本文设计了实验系统，包括复杂对象的拓扑关系表达与计算程序、图斑地类面积的计算程序、基于空间拓扑关系规则的地籍数据库质量检查功能，以及时空拓扑关系和变化语义分析等原型，验证了拓扑关系表达模型和计算方法的可行性和实用性。

We give a sufficient condition for the self-similar set in the plane which is homeomorphic to the unit disk.

最后一章讨论自相似集的拓扑结构，给出了平面上的自相似集同胚于单位圆盘的充分条件。

We prove in this paper that topological entropy is zero, in systems of equivariant mapping, that systems of compression mapping, and systems of the homeomorphism of unit circle onto itself, while the toppological entropy is positive, that extensible mapping in the compact toppological metric space.

证明了在一般的紧致度量空间上，等距映射的系统，压缩映射的系统，单位圆上的自同胚映射的系统等的拓扑熵都为零，而可扩映射的系统有正的拓扑熵。

The number and distribution of the singular points of streamlines in the cross section of steady flow through a curved tube are discussed by using the method of topological structure analysis.

利用拓扑结构分析方法，分析了弯曲圆管内定常流在横截面上流线的奇点个数及分布规律，给出了二次流的漩涡数目由 2个变为 4个，流态结构发生分叉现象的理论判据·进而，利用Galerkin方法，得到了弯曲圆管内定常流的流函数和轴向速度的半解析表达式，给出了流态结构发生分叉现象的临界Dean数，所得结果与理论判则一

The innovations of this paper as follows:(1)The topological relation model between complex spatial objects is brought forward, which represented by some composite basic 9I matrix and results in general signification.(2)Time and space integrated topological model is suggested to reason about spatio-temporal change types;(3)Sweep-line algorithm is improved, and a new little circles of polyline nodes overlapped with region method is proposed. As result, it's efficient to calculate line-line, line-region and region-region topological relations.

本文的创新之处在于提出了一种能够描述复杂对象的数学表达模型，将复杂对象间的复合拓扑关系表示成基本拓扑关系的组合，具有一定的普适意义；研究了时空拓扑关系的内涵和表达方法，说明利用时空拓扑关系可隐性地实现时空变化语义的查询；对平面扫描线法进行了改进，提出了一种新的节点微小圆求交的算法，可有效地解决线面、线线、面面拓扑关系的计算问题。

Through topological theory and principle on flow analysis, draw out the topological characteristic of near field in round jet: the amount, connecting forms of critical point and primary bifurcation.

通过拓扑分析的方法，给出了横流中圆孔射流近区流场的拓扑性质：流场中奇点的类型、数目、连接方式及生成的主要流动分离线。

Through topological analysis, draw out the topological characteristic of near field in slot jet: the amount, connecting forms of critical point and primary bifurcation, it have the same topological characteristic with round jet in despite of they have a different flow forms.

我们发现虽然有限长窄缝射流与圆孔射流在流动情况上存在一定差异，但它们近区流场的拓扑性质却是一致的。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。