查询词典 descriptive geometry

Applying theories of Vector geometry and differential calculus, this paper aims to infer the internal force and geometry equations for curved beam, whose axis curve is parabola and being distributing-load.

目的 对形心轴线为二次抛物线形曲线梁的内力、几何方程进行理论分析与公式推导。

In this dissertation, InGaAs/InGaAsP/InP MQW microdisk laser and its characterization were presented. Some conclusions are as following: the characteristics of lasing threshold was discussed by using rate equation. The dependent relations between threshold and cavity volume, spontaneous emission coupling efficiency β were investigated. The whispering gallery mode and spontaneous emission in a microdisk geometry were then studied. Almost all spontaneous emission was coupled into the lowest order TE mode when the normalized thickness of photonics well was between 0.15 and 0.5. The design principle and device process of InGaAs/InGaAsP/InP MQW microdisk laser were presented. The microdisk lasers with the diameter of 8μm, 4. 5μm and 2μm were succesfully fabricated by using etching techniques. The pulse lasing thresholds for the microdisk with the diameter of 8μm and 4. 5μm were 170μW and 15μW, a record results compared with the published in the literature. The cw lasing threshold for a 2-μm-diameter microdisk was only a few μW. We haven't found similar report up to now. To solve the problem of directional output in a microdisk laser, the power coupling efficiency in a double disk geometry was investigated with the theory of waveguide mode couple. A new structure of electrically pumped microdisk laser with output waveguide was designed, making a foundation for the practical use of microdisk laser.

本文主要研究InGaAs/InGaAsP/InP多量子阱半导体碟型激光器的研制和特性表征，并取得如下结果：利用速率方程理论讨论了激光器激射阈值的特性，分析了阈值与腔体积和自发发射耦合系数β之间的关系；讨论了微碟光子阱结构中的自发发射特性和微碟中WGM模式特性；光子阱结构在其归一化厚度在0.15-0.5之间时，几乎全部自发发射进入到最低阶TE模式中；研究了InGaAs/InGaAsP/InP多量子阱微碟激光器的结构设计原理和器件的制备工艺；利用刻蚀方法成功制备出直径分别为8μm、4.5μm、2μm的碟型微腔激光器；直径8μm和4.5μm的微碟脉冲光泵浦激射阈值分别为170μW、15μW，是目前所见文献报导中比较低的；直径2μm的微碟连续光泵浦激射阈值仅几μW，目前尚未见到达到类似结果的研究报导；为解决微碟激光器激射光定向引出的问题，通过波导耦合模理论分析了双层碟之间功率耦合效率；据此设计了新型带耦合输出波导的电泵浦微腔激光器，为进一步研制可实用的电泵浦微腔激光器打下基础。

Besides having a some insight into theinternal structure of operator algebras,it gives a greatimpetus to the development of modern mathematics towords thenon-commutative direction,especially to the developement ofnon-commutative geometry,non-commutative algebraical topologyas well as non-commutative algebraical geometry.

除了反映算子代数自身的内在性质之外，它还对于现代数学朝着非交换的方向发展起着积极的推动作用，特别对于&非交换微分几何&，&非交换的代数拓朴&，甚至&非交换的代数几何&等非交换的数学学科的发展具有重要的影响。

For the first tin atom, it appears to be seven-coordinated with a distorted pentagonal bipyramid geometry, and the other is five-coordinated with a distorted trigonal bipyramidal geometry.

其中一类锡原子呈七配位畸变五角双锥构型，另一类呈七配位畸变三角双锥构型。

The endocyclic Sn atoms exist in a distorted triginal bipyramidal geometry with the coordination number of 5. The exocyclic Sn atoms form 6 significant bonds and exist in a distorted octahedron geometry.

化合物12的X衍射单晶测定表明，化合物是以Sn2O2四元环为中心的中心对称二聚体结构、内环锡为5配位的畸变三角双锥结构、外环锡为6配位的畸变八面体结构。

They are active ingredients of an animate geometry that embraces the linear and non-linear.Both Cartesian and post Einsteinian geometry are encompassed by it.

他们是动态几何学的重要组成，这种几何学同时包含线型和非线性概念，超越了传统笛卡尔和后爱因斯坦几何的界限。

The calculation takes into account the effects of grating period, noncollinear amplification geometry, crystal's length and pump intensity. The results show the grating period of PPLN and the noncollinear geometry has effects on the spectral bandwidth.

计算结果表明，参量带宽和增益带宽具有相似的特性，而且PPLN晶体的周期和非共线入射结构会对光参量放大的光谱带宽产生一定的影响，在同一波长处，通过调节晶体周期或非共线结构可以获得更大的带宽。

Some pointwise geometry properties directly depict the geometry speciality of space.

有些点态几何性质直接描述空间的几何特点。

Dependence of flashover voltage on several physical factors, that is applied voltage waveform, predischarge conditioning, geometry shape and length, geometry area, dielectric material, surface treatment, magnetic field effects and multilayer high gradient insulator technology, are expatiated.

文中系统总结了目前高压真空绝缘闪络特性的实验研究成果，具体阐述了几种典型实验模型及研究方法，以及几种重要物理因素，即绝缘材料介电常数、绝缘体几何形状及长度、施加电场波形、绝缘体表面处理、绝缘体几何面积、绝缘体预放电处理、磁场作用、多层高梯度绝缘技术等等，对真空绝缘闪络特性的影响。

For every major character and static mesh asset, we build two versions of the geometry: a renderable mesh with unique UV coordinates, and a detail mesh containing only geometry.

对于游戏中的主要人物角色和静态对象，我们通常都会制作两个版本的模型：一个使用了独特贴图坐标的实时低模和一个充满了细节的高模。

The quality of both red and white wine depends very much on the wine maker talent and on the quality of the grapes.

他的红酒和白酒的品质，根据酿造者的能力和葡萄的质量，各有差异。

No, I don't want to get drunk before my next match.

" "不，我不想让我的下一场比赛前喝醉了。