二轴的

Secondly, in our methods, the essential geometry of the image single axis geometry may be specified by six parameters and this may be estimated from one conic and one fundamental matrix (a total of 12 parameters) or may be minimally estimated from two conics (a total of 10 parameters).

本文证明了单轴旋转运动的不变量可以通过一个基本矩阵和一条二次曲线来确定，在这种情况下，由于基本矩阵的自由度为7，二次曲线的自由度为5，所需确定的参量个数仅为12，大大减少了不变量的计算量；本文同时证明单轴旋转运动的不变量可以通过最少两条二次曲线来确定，在这种情况下所需确定的参量个数仅为10，该方法是目前同类算法中参数最少的；本文提出了用多条二次曲线求解单轴旋转运动的不变量的最大似然估计算法，其所需确定的参量个数为6+2n，其中n为二次曲线的个数，该公式更深刻地反映了二次曲线与不变量的参数关系。

Seven types of dimetric drawing and three types of trimetric drawing are introducedby the author with an aim to help hasten the shift of the principles derived from varioustypes of dimetric and trimetric projections from the theoretical approach to the field ofpractical use,and to alleviate the embarrassing situation that only the simple methodscan be resorted to in drawing the pictorial projections by isometric drawing and cabinetdrawing.

为了使各种形式的正二测和正三测从理论研究转向实际应用，克服长期来人们在绘制轴测图时，多数只能采用正等测和斜二测等单调情况，以及提高绘图速度，本文推荐采用七种正二测和三种正三测，并设计一套绘制这十种正轴测的专用工具--轴测多角比例尺。本文提出一套近似作这十种正轴测坐标面上椭圆的方法和数据，使其既简便又准确。

In general, the design work with traditional measures is done by hand, which cannot meet the needs of the technology and manufacture. So the author has developed a CAD hydraulic design software fit for lower specific speed axial flow runner, which is easily operated by users.The main research work of this paper is as follows:1 Analyzing the main reason of axial flow power station cannot work well under littler volume of flow in some season and putting forward an improving scheme, pointing out the characters of design under abnormal factors.2 Combined with the development of the industry in our country, the abnormal hydraulic design method of propeller turbine is discussed based on present literature, data and experiment results.3 Guided by the design method of software engineering, a suit of hydraulic design software of Lower Specific Speed Axial Flow Runner is programmed by the object-oriented programming language Visual Basic and a straightforward, concise and standard Windows human-computer dialogue interface is designed for the system, which makes the operation of the system very convenient.4 ActiveX Automation technology is adopted as the interface with AutoCAD and the hydraulic drawings are edited, modified by AutoCAD until hydraulic model drawings according with the demand of engineering practice are output.5 To resolve practice problem, the author has designed a lower specific speed axial flow runner for Duowa Power Station through an example.

论文的主要内容有：1 深入分析很多轴流定桨式水电站枯水季节小流量下不能发电的主要原因，提出减容改造方案，并指出超常规条件下的改造设计特点。2 结合国情及行业发展需要，参考现有资料、文献和前人的研究成果，进行低比转速轴流式转轮叶片水力设计方法的研究，对轴流式转轮叶片的奇点分布法水力设计进行了全面的探索，结合现代计算机技术，找到了一种针对特殊条件的轴流式转轮叶片水力设计方法。3 仔细比较多种AutoCAD二次开发工具后，结合本课题的特点，选用Visual Basic语言，综合应用软件工程的设计思想，进行低比转速轴流式转轮叶片水力设计软件的编制，为系统设计了直观、简洁和标准的Windows人机对话界面，便于用户操作；编程时在考虑到设计条件特殊性的同时，尽量做到程序的通用性，使之可用于解决同一类问题；另外，大部分程序还可移植到普通轴流式转轮叶片水力设计中，具有良好的适应性。4 利用ActiveX Automation技术与AutoCAD接口，对AutoCAD进行二次开发，在AutoCAD下实现水力图的自动生成和编辑，直至输出符合实际工程要求的木模图。5 通过算例，为多哇水电站设计了一个低比转速轴流定桨式转轮，解决其在枯水期小流量下不能发电的问题。

First, an optimization algorithm based on the constant linear velocity mathematical model of the camshaft was proposed according to the least square method to finish the curve optimization and simulation, and the fluctuations of the speed and acceleration curves were reduced.

根据凸轮轴恒线速加工的数学模型，提出一种基于最小二乘法的速度优化算法，对加工过程运动曲线进行优化仿真，得到了波动较小的速度曲线并减小了联动轴加速度的跳动。

According to the different orientations of domain walls with respect to the (100) observation plane of a foil, 90°domain boundaries may be divided into two kinds. one is thin lens or ring shaped a-a 90°domain boundary, and the domain wall lies on the {110} plane; Usually, most of these domain boundaries are uncharged; according to the extinction rules for the (011) domain walls, the displacement vector 〓 along 〓 can be dertermined, which is parallel to the line of intersection between the domain wall and the plane consisting of spontaneous polarization vectors on both sides of domain boundary; from selected area electon diffraction of crystals including domain boundary, we not only examine slight difference in the crystal parts on both sides of the domain boundary, but also obtain crystallographic relationship between them, that is, there exists a 180°rotation symmetry operator along a normal of domain wall. The other is Z or ring shaped a-c 90°domain boundary along {010} direction, and the displacement vector 〓 runs along 〓 direction.

根据界面相对于样品中(100)观测面取向的不同，90°畴可分为两类：一类为薄透镜片状或环状的a-a90°畴，其界面平行于{110}，多数不带电，由消光规律可确定其位移矢量平行于畴界面与自发极化所在平面的交迹，即，〓方向，而从包含畴界的选区电子衍射图可知，这种不带电的90°畴界两侧存在微小的取向差，其界面两侧的结晶学关系为以界面法线为二次轴的旋转关系；另一类为Z状或环状的a-c90°畴，其界面平行于[010]或[001]，相应的位移矢量为〓方向。

Under the condition of small angle misalignment, the effecton output beam's near-field distribution of CO2 lasers with two-dimensional axisymmetric-fold combination cavity was ascertained after analyzing and simulating beams combination output based on the axis determination of misaligned plano-concave and concave-plano-concave cavity resonator.

为了研究小角度失调对二维轴对称－折叠组合腔CO2激光器输出光束的近场分布的影响，在利用矩阵理论确定平凹谐振腔和凹－平－凹谐振腔失调后的光轴的基础上，采用光束并和思想，对输出光束进行了理论分析和模拟。

By rotating the X-axis of the measurement coordinates, the straightness data of each generatrix are transformed into a unified 3D coordinate system whose Z-axis superposes the least square mean axis calculated with the data of the multiple generatrices. The computer simulations and experiments prove that the construction by rotating the abscissas can effectively eliminate the distortion of the constructed profile.

通过测量坐标系中X轴的旋转，将各条母线直线度偏差数据统一到同一个空间坐标系中，采用两端面圆的最小二乘轴心的连线作为零件轴线，消除了直接构造所带来的表面变形，并能进一步计算出被测内孔的直径、圆度和轴线直线度误差，使测量系统集成化和多功能化。

The results of this study indicate that changing the angle of the intake port has a profound effect on the flow field during the intake stroke of the engine cycle. For the case with the intake-exhaust valves canted at zero degree (the so-called vertical valves), the tumble ratio, swirl ratio, turbulent intensity, and turbulent kinetic energy in the direction perpendicular to the bisecting plane of the cylinder are at their highest levels than those obtained for the other cases. This effect is most pronounced after the compression stroke of the cycle. As a result of this study, it is observed that the behavior of the overall flow field from the intake to the completion of compression stroke has a major impact on the effectiveness of the mixing of fuel-air prior to the ignition of the engine cycle.

结果显示，改变进排气阀的倾斜角度对进气期间的流场变化有很明显的影响，其中以垂直阀(进排气阀倾斜0度)所得的 Y轴向(Y方向系垂直於将汽缸对分为二平面的方向)滚流强度、涡漩比、紊流强度、紊流动能等流场强度为最强；若以流体经活塞压缩后的流场特性进行探讨，所得结果显示压缩冲程对汽缸内流场的效应是不容忽视的；因此由进气到压缩过程结束的整体流场现象，才是影响引擎点火前的油气混合程度与燃烧品质的关键。

The mirror is applied in laser beam expand system, it can not only control the sending and incepting directions of the high energy laser beam accurately, and adjust the oblique high energy laser beam, but also can improve the beam quality by minishing the mirror thermal distortion.

本文介绍了一种应用于高能激光系统中的新型二维快速控制水冷反射镜，既可实现精确控制激光发射和接收光轴的方向，对光束整体倾斜方向进行校正，又可实现减小镜面热畸变提高光束质量的功能。

The models of cutting edge, the flute of ball end milling cutters with spiral flute of different section, and the section profile and relative feed speed of grinding wheel are provided.

分析了三种不同定义的螺旋刃口曲线的异同和与优劣，给出了二轴联动数控加工时不同截形的螺旋沟槽球头铣刀的刃口、沟槽及砂轮截形、相对进给速度等设计模型，并通过实得沟槽及计算机模拟结果进行了验证，认为借助该模型可获得较理想的球头回转铣刀。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。