查询词典 quadrilateral

All quadrilateral mesh automatic generation for regular quadric surfaces based on Auto CAD AME;2. Represent Quadric Surfaces Using NURBS and Calculate the Control Vertecs and Weights;3. Through study,the property is found out that planes cutting edgewise quadric curve and quadric intersections from the quadric surfaces become the harmonic division.

文中采用了射影几何的方法，证明了画法几何中关于两个二次曲面相交的著名的复切定理和蒙日定理，通过研究得出了周切线平面和交线平面成调和分割的性质，同时还得出了处于复切的二次曲面必存在相公切的二次曲面的性

The results are listed as follows:(1) In peneplain with plenty water-resource, hexagonal spatial structure of urban system can be formed. Due to differential competed function of central places, the hexagonal system is distorted. The result is that the area covered is decr eased and the girth is unchanged——but every border is usually unequal;(2) A pattern of pentagonal system evolves from hexagonal system controlled by a river;(3) A pattern of quadrilateral develops from hexagonal system under two parallel rivers;(4) The equal distance distribution of central places in narrow geographic space has its special reasons. The results are very important for understanding urban's formation and development and urban plan in Huang-Huai-Hai plain.

本文通过自然地理因素中水文、地形这两个重要要素对城镇体系空间结构形成的影响，分析了华北平原区在不同要素影响下的城镇体系空间结构样式：①在水源充足的准"均质"河北冲积平原上，基本满足六边形形成条件，但由于周边中心地发展竞争力不同，故使得正六边形发生畸变——覆盖面积减小而周长却保持不变；②构建了在一条河流影响下的六边形网络结构朝五边形网络演变的模型；③构建了在平行状河流作用下六边形网络向四边形网络演替的模式；④指出了在水源充足的狭长地理空间，城镇体系空间结构发育成等间距的现象与原因。

In this dissertation, the meshing techniques, especially for unstructured quadrilateral and hexahedral elements, are discussed, and the relative techniques, like the node smoothing and the reduction of matrix profile of a mesh, are also discussed.

本文全面回顾了四边形和六面体有限元网格特别是非结构网格生成技术，对相关的技术如网格节点位置平滑和带宽优化等技术进行了总结，并详细的描述了有关的算法。

In chapter six, A finite element model to evaluate the mechanics properties of thin wall structure is put forwards. The 4-node quadrilateral Hughes-Liu shell element with five through-the-thickness integration points is employed. The material is assumed to satisfy the elastic-plastic yield condition with isotropic hardening. The single surface contact algorithm is taken to deal with the contact searching. The priori stabilization procedures for the numerical control of the hourglass instability and the penalty method for the evaluation of contact force are used. The classical Coulomb law of friction is employed to evaluate the friction force.

第六章采用法向方向5点积分的4节点Hughes-Liu壳单元，前置参数法砂漏控制技术，等向强化弹塑性材料模型，分步增量应力回映方法，一体化接触搜寻算法，罚参数接触力计算方法及经典摩擦定律，建立了一种计算受冲薄壁结构大变形力学特性计算的有限元模型，通过对汽车A传动轴及汽车纵向方形吸能梁的大变形力学特性分析，验证了该有限元模型的正确性。

In the subjects given, learners operate an integrated simulator landing stage of flight data to meet the aircraft and instructors to give students hands-on consolidated results. And then for the visual route trilateral, quadrilateral, and five edge-to-landing phases, with 37 operators' experiments through interviews with senior instructors, the instructors selected seven simulator modules to assess and define the effectiveness of the actual operation of the parameters. Through the way of neural network learning , the establishment of the definition of parameters of simulator training with the students finished the cause and effect comprehensive results relationship, so this research create a set of objective assessment of the effectiveness of flight training simulation platform.

在给定同样操作课目之下，以学员操作落地阶段之模拟机综合飞行数据，配合学员实际操作飞机教官给予之综合成绩，再针对目视航线三边、四边及五边到著陆阶段，以37位操作者为实验，各选取七个模拟机数据，透过资深教官访谈，定义教官评量学员实际操作成效之参数，透过类神经网路的学习，建立模拟机定义参数与学员完训综合成绩的因果关系，如此即可建立一套可以客观评估飞航训练成效的研究模拟平台。

A quadrilateral or triangular sail set from the after part of the mainmast on a fore - and - aft rigged vessel.

这艘三桅帆船的前桅和主桅上都有相同的斜桅桁下帆和顶帆。

A quadrilateral or triangular sail set from the after part of the mainmast on a fore-and-aft rigged vessel.

帆桁吊在桅杆上一头渐细的长柱，用来支撑和展开横帆、梯形帆或三角帆的顶端

To establish the constitutive equation of material, the metric tensor for stress , strain and their transformation equations between different configurations are derived, and basic theory of finite deformation as well as elasto-plastic deformation criterion are studied. By analyzing the applicability of different element models, four-node quadrilateral degenerated Mindlin isoparametric element is adopted because of its good versatility, and the element stiffness matrix is derived. The static implicit elasto-plastic finite element equation for complex skin stretch-forming is put forward based on Updated Langrange formulation.

本文首先系统地阐述了有限变形的相关基本理论，针对板料成形建立了应力应变度量张量及其相应的转换关系；介绍了材料的屈服准则、塑性变形强化规律、塑性流动规律以及加、卸载准则，并在此基础上建立了有限变形各向异性弹塑性本构方程；对板料成形的单元模型进行了分析，针对飞机蒙皮零件特点，采用通用性强的四节点四边形退化Mindlin等参壳单元进行成形模拟，并导出其单元刚度矩阵的具体形式；基于以上研究，以逐级更新Langrange描述的持续虚功率原理为基础，建立了率形式的复杂蒙皮拉形过程静态隐式弹塑性有限元方程。

A two - mast ed sailing ship,square - rigged on both mast s,carrying two or more headsails and a quadrilateral gaff sail or spanker aft of the mizzen mast .

双桅横帆船有两根桅杆的帆船，每个桅杆上都有横帆，载有两个或更多的前帆和一个四边形的斜桁帆或在后桅的尾部装有后樯纵帆

A two-masted sailing ship, square-rigged on both masts, carrying two or more headsails and a quadrilateral gaff sail or spanker aft of the mizzenmast.

有两根桅杆的帆船，每个桅杆上都有横帆，载有两个或更多的前帆和一个四边形的斜桁帆或在后桅的尾部装有后樯纵帆

The labia have now been sutured together almost completely.The drains and the Foley catheter come out at the top.

此刻阴唇已经几乎完全的缝在一起了，排除多余淤血体液的管子和Foley导管从顶端冒出来。

To get the business done, I suggest we split the difference in price.

为了做成这笔生意，我建议我们在价格上大家各让一半。