查询词典 geometry

English Description It aim at: developing comprehension of algebra, trigonometry, analytical geometry, derivation and integral, activating capabilities of logic inference and induction, enlightening confidence and independence, strengthening calculating abilities with an emphasis on its application and graph, furnishing a sound basis for future specialty.

Chinese Description 本课程希望在二学年中，能使学生对代数、三角、解析几何、微分及积分有充分的了解、培养逻辑推理、启发思考创造、强化计算演绎并注重应用与作图，以建立同学未来学习工程数学及相关专业课程之数学基础，充分达到学以致用的目的。

Shadow effect can not be neglected for thermal analysis of spacecraft,Accroding to the angle between solar light and antenna orbit plane and its orbit location,analytical geometry method was used for accurately calculating solar radiation heat flux distribution of reflector surfaces.To analyze the temperature field under heat flux,the formulations of net radiation flux density between two gray elements and the net flux density of gray surface under external thermal flux were deduced.Based on the characteristic of space environment,the nonlinear temperature distribution in transverse direction of reflector shell self radiation were considered,the finite element formulations were given for orthogonal material layered shell by Galerkin method.A layered element including a inner heat source layer was proposed,and the finite element formulation expressed by DOF of the inner heat source layer were put forward with temperature and heat flux boundarys between adjacent layer.

单馈反射面赋形天线是未来星载天线发展的一个重要形式，分析了基于物理光学、几何光学和几何绕射理论的理想反射面辐射场；介绍了基于几何光学的反射面天线赋形方法；针对赋形过程中辐射场的快速分析要求，比较分析了基于物理光学的Fourier-Bessel和Jacobi-Bessel级数展开方法以及GB展开分析方法；利用GB展开快速分析方法在20GHz频率下对0.6m口径的天线进行赋形分析，实现中国大陆的30dB增益覆盖，通过数值计算研究了固定增益期望下的口径尺寸随频率的变化，以及频率为20GHz的不同尺寸天线赋形后的覆盖目标区域最大增益的变化情况。

MathCAD ; analytical geometry ; FRAME ; animate ; programme

MathCAD ；解析几何；帧变量；动画；编程

With respect to syntax, the roles of tagmeme in the structure of word and sentence and Chomsky's Generative-Transformational Grammar are discussed. The spatial relation theory and existing research achievements are investigated. Having noticed the shortage of the capability of topological and metrical relation in the description of spatial information structure, the author proposes Combinational Qualitative Geometry based on the two invariables under ordinary transformations, distance ratio and direction difference, the CQG-based spatial relation system between topological and metrical constraint is thus constructed, on which several spatial relations such as parallel, perpendicularity, co-linearity, sequence and direct neighborhood are derived. Based on extended theory of spatial relation, the language anamorphosis is analyzed from the aspects of phonetics, semantics and syntax. The mere geometric and formalized spatial relation is then integrated with concrete geographic ontology to accommodate richer and indicative spatial configuration of spatial information in the different geographic context. Finally a syntax framework for spatial information is put forward.

在语法结构方面，首先阐述了法位和法素在语法结构词法和句法中的地位和作用，以及Chomsky生成转换语法的核心内容；详细介绍了地理信息系统空间关系理论及现有的研究成果；在分析现有的拓扑关系和量度关系对空间信息结构描述能力不足的基础上，提出了基于长度比和角度差两个不变量的组合定性几何，以此建立了介于拓扑及量度约束之间的组合定性关系体系，并以此为基础派生出平行、垂直、共线、次序、直接邻近等空间关系描述；本文基于扩展的空间关系理论，详细讨论了空间关系在语音、语法和语义三个方面的语言变体，将纯几何和纯形式化的空间关系与具体的地理本体结合起来，可以获得更为丰富的、更能反映空间关系在不同语言上下文中具体体现的组合关系；最后给出了一个空间信息的语法结构的基本框架。

This thesis is aimed to study the two boundary ductile shear zones of the Qilianmicrocontinent, both of them are large ductile strike-slip shear zones, and to understand thecharacteristics and nature of shearing, original mechanism, and their contribution to the orogen,through the investigation of their spatial distribution, geometry, structural analysis, chemicalcomposition of mylonite and syntectonic anatexis, and geochronology.

祁连微地体的南北边界均为大型韧性走滑剪切带。本论文旨在通过调查这两条韧性剪切带的空间分布、几何学和运动学特征，形成的温压条件、时代，探讨这些大型韧性走滑剪切作用的特征、性质，形成机制，以及它们对造山作用的贡献。

ABSTRACT In this paper, an investigation on the helical ports was carried out in a steady-flow rig. The three velocity Components of air flow through the intake valve of several typical helical ports were measured by hot-wire anemometry for analysing the relationships between intake port geometry and swirl level as well as flow resistance.

本文在稳流气道试验台上对螺旋进气道进行了大量的研究，为了分析螺旋进气道的结构形状与涡流强度及流动阻力的关系，采用热线风速仪测量并分析了不同气道的气门口气体流速。

The process of the algorithm include: image enhancement, using self-adapting threshold value reduce redundance, using Hough transformation extract first feature line, according to the vertical projection of the horizontal gradient perform characters line, using the improving Hough transformation with angle constraints acquire the intersection of the two feature lines, according the characters of geometry position to judge the fault.

算法流程包括图像增强，自适应阈值变换滤除无关特征，应用Hough变换提取主特征线条，依据线型特征图像水平梯度沿垂直方向的积分投影定位主特征线，基于极角约束Hough变换推出两条主特征线交点，最后根据安全链和支架的几何形态特征判读故障。

The mechanics model of a ball screw was developed considering the factor of lead angle,and the main curvature of the helical surface was deduced using differential geometry method,and the effect of lead angle on the elastic deformation was analyzed.

考虑螺旋升角的因素，建立了滚珠丝杠副的受力模型，应用微分几何理论推导了螺旋面的主曲率，并进一步分析了螺旋升角对滚珠丝杠副弹性变形的影响。

In this thesis,based on the DFT+NEGF first-principles method,we construct a lead-molecule-lead sandwich system with single benzene-based molecule to investigate the relationship between the structure and properties of the molecular devices and the factors that influence properties of the molecular devices.Our computational investigations on these molecular devices are primarily concentrated on the effect of contact geometry between molecules and electrodes,the effect of side groups,the effect of different torsion angle between two phenyl rings and the effect of external electric field.This thesis consists of five chapters:In Chapter one,we mainly introduce the research background and development of the molecular electronics,including the experimental fabrication of molecular electronic components and theoretical simulation methods.Afterwards we discuss the questions that need to be solved in this area.Finally,the main contents of this thesis are listed.In Chapter two,we introduce the theoretical methods used in this thesis, including the main first-principles calculation methods,i.e.,the Density-Functionmethod and nonequilibrium Green\'s function.

本论文拟采用密度泛函理论和非平衡格林函数相结合的第一性原理计算方法，选取苯基小分子作为研究对象，构建了金属电极/有机小分子/金属电极三明治结构体系，系统地研究了苯基分子器件结构的改变与分子电输运性质之间的关系以及影响分子器件电输运性质的相关因素，其中重点研究了分子与电极间可能的接触结构改变、官能团、分子间的扭转角以及外电场对苯基分子电输运性质的影响，本论文主要包括以下五个章节的内容：第一章为综述部分，主要介绍了分子电子学产生的背景、分子器件的研究意义、当前研究分子器件的实验和主要理论方法，以及目前在研究分子器件中存在的一些问题，最后给出了本论文的主要研究内容和技术路线。

According to the target angular coordinates on detector, geometry of roll-pitch seeker and its location relative to the missile, the modeling of tracking gimbal angles error signals were derived to realize the close loop control of the roll-pitch seeker.

根据导引头探测器上目标的位置信息，导引头稳定平台状态及导引头与弹体间的相对运动关系，导出了导引头跟踪框架角误差信号的数学模型，以实现导引头的闭环控制。

Must have Coordination and negotiation skill, flexible ideas, and be punctilious person.

必须具备较好的协调与谈判能力，头脑灵活，工作认真仔细

Result: 18 patients are all with simple eye.The pigment mole lies in nasal and temple sides of the ball conjunctiva,in which 2 lie in lacrimal caruncle and semilunar plica.

结果：18例患者均为单眼，色素痣大多数位于内外侧睑裂部球结膜面，2例位于泪阜及半月皱襞，经激光治疗后，10例色素痣消失，有5例行再次激光后消失，2例行第三次激光后消失，1例第四次激光后消失。