几何基础

In the third chapter, the concepts of loop circuit and variational geometric constraints network are firstly presented.

本章为下一章的变动几何约束网络理论的建立奠定了坚实的数学基础。

Based on the geometric model, 3D finite element models of segments of preoperative and postoperative vertebrae were created.

在几何模型的基础上，分别建立椎体成形术术前和术后L1~2的腰椎段三维有限元模型。

In this article, based on an analysis of the geometrical property for waviness and roughness,it is suggested that it is unnecessry to find a parameter of the complete separated component of waviness and roughness.

本文在分析表面波纹度和粗糙度几何特征的基础上，提出没有必要寻求一个截然分离表面波纹度和粗糙度参数的看法。

Just under this background, studying on the flight mechanism of flapping-wing MAV and sample fabrication from the bionics are conducted in this dissertation. The kinematics equations of insect wings can be acquired by the observation and measurement on the natural insect in researching paper. The geometry model of insect is established by UG technology. The three dimensional grid during the insect moving in the flow field is achieved which adopted grid generation method. The characteristic of lift and drag are attained by simulation the surround flow field during the locomotion of wings, and the flight mechanism of insect is discussed. Based on this study, the physical flapping-wing MAV is fabricated by the acquirable materials and parts of apparatus in existence.

正是在这一背景下，本文从仿生的角度来研究微型飞行器的飞行机理与样机制作；通过查阅文献中对自然界中昆虫翅膀运动的观察与测量，获取了昆虫翅膀的运动方程；采用UG建模技术，建立昆虫的几何模型；采用网格划分方法，获取昆虫在流场运动时的三维网格；运用CFD方法模拟翅膀运动时周围的流场，获取昆虫运动时的升阻力特性，进而来研究昆虫的飞行机理；在此基础上，通过现有可用的材料加工制作仿生微型飞行器。

The geometry structures have been optimized by semiempirical method AMI, on the base of this, the electronic properties and energy band structure of typical polymers were performed by EHMACC. The influence of photo-electricity on PPV-like electroluminescent polymers substituted by alkyloxy and cyano were discussed.

采用半经验AM1方法优化体系的几何结构，在此基础上，对典型的聚合物采用EHMACC程序计算能带结构，讨论烷氧基和氰基取代对PPV类电致发光聚合物光、电性质的影响。

Based on the energy principal method, an analytical method is provided for studing calculation of the push force and for shape design of the mandrel. This research method reveals the change law of the displacement modes influenced by the change of cone. It may be used for reference for further studing autofrettage technique.

以能量原理为基础的研究方法为研究机械自紧技术的冲头推力计算和冲头几何形状设计提供了一种分析方法，该研究方法揭示了锥角变化影响位移模式的变化规律，给深入研究自紧技术提供了参考。

Aiming at researching on the theory of the shaft-kind parts form error evaluation and its application, on the basis of the analysis for the geometric model of the roundness error and cylindricity error, the linear programming models of the enclosure evaluation were proposed. According to the features of the proposed models, the solution of the optimization algorithms of linear planning was discussed to obtain accurate evaluation results.

为了对轴类零件形状误差评定理论及应用进行研究，在分析轴类零件的圆度、圆柱度误差评定几何模型的基础上，建立了包容拟合评定的规划数学模型，并针对模型的特点，探讨了使用线形规划的单纯形优化算法进行规划模型的求解，从而获得精确的形状误差评定结果。

The generalized criterion for minimum zone in the determination of form error of surface is presented on the basis of linear minimax techniques, and the criteria of such surfaces as for cylindricity and straightness with arbitrary direction are derived from this generalized criterion.

本文讨论形状误差最小区城的判别准则和判别方法。根据线性极差极小化问题解的特征，给出形状误差最小条件的统一判别准则。推导出各种形状误差最小区域判别法(包括圆柱度误差和任意方向直线度误差)，并在几何判别的基础上得出代数判别的格式。

On basis of the deformational and geometrie texture analyses of main faults in Shibanxi area, model of fault space textures and their ore-control rule are studied.

本文在解析石板溪金矿区主要断层变形结构和几何结构的基础上，探讨了其空间结构模式和控矿规律。

Yield rule, intensify rule, fluxion rule, types of contact and diathermanous model of metal cutting were also analyzed detailedly.

本文在直角自由切削过程分析的基础上，讨论了金属切削过程中的弹塑性变形理论和温度场理论，详细分析了屈服准则、强化准则、流动准则、金属切削传热模型、接触类型等问题，并利用有限元的基本思想，建立了直角自由切削应力场和温度场的有限元模型，进行了状态非线性、材料非线性和几何非线性的热力耦合分析，重点研究了切屑分离标准的确定、表面接触类型的处理等问题。

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。