拓扑结构

Within algebraic geometry is the description of geometric objects as solution sets of polynomial equations, combining the concepts of quantity and space, and also the study of topological groups , which combine structure and space.

在代数几何里，把几何对象描述成多项式方程的解集，结合数量和空间的概念；也研究拓扑群，结合了结构和空间。

Refers to the port in an FDDI topology which connects the incoming primary ring and the outgoing secondary ring of the FDDI dual ring. This port is part of the dual attachment station or a dual attachment concentrator.

指FDDI拓扑中的端口，连接FDDI双环结构中的输入主环和输出辅环。A端口是双连接站点或者双附加配置集中器的一部分。

Application of topology optimization in the structure design of aero-engine pylon is studied.

研究了拓扑优化技术及其在航空发动机吊挂结构设计中的应用。

Then the spatial index is constructed which includes not only the external approximate expression but also interior approximate expression of spatial object and is extended from tranditional index only with external approximate expression. The index structures of MR-tree and MRD-tree based on multi-approximate expression are set up with the prototype index of R-tree, and the relevant algorithms about the index of insertion, deletion and search are provided. Then, the efficiencies of constructing index based on the multi-approximate expression and window range query are analysised and compared. In addition, the several algorithms and efficiency of soving the maximum enclosed circle and maximum enclosed rectangle are discussed and analyzed during constructing index based on multi-approximate expression.

首先，论文讨论了空间数据的特点、空间数据库的关键技术以及空间对象间的拓扑、距离以及方向关系，分析了空间对象的外部和内部近似表达，然后将传统索引中只利用空间对象的外部近似扩展为既有空间对象的外部近似又有空间对象的内部近似，即以空间对象的多重近似来构建索引，并以R-tree为索引原型构建基于多重近似的MR-tree和MRD-tree索引结构，然后给出了相关索引的插入、删除及查找算法，并通过实验比较分析了基于多重近似索引与基于外部近似索引的构建效率及窗口范围查询效率。

According to the characteristics of distribution networks,a backward topology method is adopted considering the status of the switches and the equivalent loss proportion by which the rank of calculating matrix can be reduced,and therefore it can increase the overall calculating speed.

根据配电网的结构特点，采用了计及网络开关状态的逆序拓扑方法和等效损耗分摊，以降低计算矩阵的阶数，提高整体计算速度。

A new method for structural static reanalysis of topological modifications was presented.

提出了一种新的结构拓扑修改静态重分析方法。

A new method for structural static reanalysis of topological modifications is presented.

本论文提出了一种新的结构拓扑修改静态重分析方法。

In the following, complex modal reanalysis methods for topological optimization of structures are studied.

本文接着研究了结构拓扑优化的复模态重分析方法。

Therefore, it is necessary to put forward fast and easy reanalysis methods of structure optimization so as to enhance the efficiency of structure optimization and speed up the optimization process, which is also one the main content of this dissertation.

因此，为了提高整个结构优化设计的效率，加快优化设计的进程，十分有必要研究快速而简便的拓扑优化重分析方法，这也是本文的主要研究内容。

It is suitable for the topological optimal design of the frame structure, especially for the reanalysis of the local optimal design.

该方法适用于刚架结构拓扑优化设计的重分析。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。