分析曲线

The results indicate that the reconstructed quintic spline curve can ensure the cutter transit well for corner contour, and that the cutting performance is superior to that of the quadratic one.

同时也重构了一条四次样条曲线与五次样条曲线作对比分析，结果表明，五次曲线能使裁刀获得良好的且较四次曲线优越的轮廓拐角加工性能。

Through the new research methods, this thesis has made the following contributions in this field: 1. For the first time the curvature radii and relative angles of a planar continuous curve at discrete points are chosen as local parameters to represent the curve, which reflect clearly the local geometrical characteristics of the curve and are easy to be dealt with.

借助于新的研究方法，本文在这一领域作出如下贡献：（1）首次提出用曲线上离散点处曲率半径和相对转角作为局部参数表示平面连续曲线，直观地反映曲线各个局部的几何特征，且便于曲线的修改和变换，并通过机构运动分析，快速求出机构轨迹的这两个局部参数。

The effect from transverse webs and frames and the effect from collision velocity on ship bow collision properties are also studied in this paper. 7. The idea of buffer bow is put forward from aspects of the overall situation of environmental protection and reducing the damage of struck shipside caused by striking bow. The influence of curvature of bow shape on mode of distortion, collision force, collision force density and energy absorption of bulbous bow is described detailedly through a series of collision numerical simulation for bulbous bows that have different curvature.

发现横向框架对于船艏结构的变形形态，碰撞力及能量吸收都有一定的影响，在进行碰撞分析时不能忽略，在较低的速度范围内碰撞速度对碰撞力及能量吸收没有太大影响，所以可以从较高速度撞击后得到的能量吸收曲线中得到较低速的碰撞能量吸收曲线，从而可以得到低速碰撞时的撞深，然后通过这个撞深在较高速碰撞的碰撞力曲线中可以获得低速碰撞的碰撞力曲线。

According to the identification of fossil woods, it shows that they all belong to Araucarioxylon, with the stage age of Qixia, though there are some anatomical differences among them; Following two mathematical clustering analysis methods-analysis of variance and CSDM curve, metrical numerical values are quantitatively analysed, then, skew value of curve and its relationship with leaf longevity are showed.

经过鉴定研究认为，本区的木化石均属于松柏类中的南洋杉型木属，为栖霞阶化石；应用方差分析、CSDM曲线相关分析等数学聚类分析方法，对木化石标本的测量数据进行了定量分析研究，探讨了曲线偏差值与叶寿命的关系，认为本区二叠纪木化石均为常绿树种-南洋杉型木，但有可能存在落叶树种，且生长年限有较大差异。

It isverified that the method for using little deformation condition was true with accurate solution of three-piece straightening curve.

文摘：基于三段矫直曲线应变速率的假设，通过计算三段矫直曲线的精确解，验证了使用小变形条件的正确性；考虑高温铸坯蠕变性能，对铸坯的力学行为进行了分析，得出了使用三段矫直曲线方法，铸坯应变速率、应力及应变在矫直区内变化较为平缓，可有效避免铸坯内裂纹的形成；使用本文三段矫直曲线精确解，调整辊列位置，可进行连铸机的在线技术改造。

It isverified that the method for using little deformation condition was true with accurate solution of threepiece straightening curve.

文摘：三段矫直曲线应变速率的假设，通过计算三段矫直曲线的精确解，验证了使用小变形条件的正确性；考虑高温铸坯蠕变性能，对铸坯的力学行为进行了分析，得出了使用三段矫直曲线方法，铸坯应变速率、应力及应变在矫直区内变化较为平缓，可有效避免铸坯内裂纹的形成；使用本文三段矫直曲线精确解，调整辊列位置，可进行连铸机的在线技术改造。

Based on the example of turbine reverse engineering , the general procedure that can be used to translate the physical object into CAD datum by Surfacer software is determined in this paper1 By going deep into the vector of point-cloud , it's parametrization can be gained by adopting the precept of accumulating chordal parametrization1 According to the principle of const ructing curve using the least square method , the high quality-curve can be gained by modifying curve's parameter1 This paper also empha2sizes on some methods about processing point-cloud , const ructing curve and const ructing surface1 And it can provide several methods to const ruct high quality2CAD model for mould machining1

此栏目为免费论文，可自行复制获取，如需要其他完整论文，可点击论文范文查找摘要本文就涡轮反求造型的实例，采用Surfacer 软件规划出由实物转化为工程CAD 资料的一般流程。在深入分析点云数据的矢量方向基础上，采用积累弦长参数化方案实现点云的参数化；根据最小二乘法曲线拟合原理，修改曲线参数获得高品质曲线；并重点论述了点云处理、曲线生成、建构曲面的方法，为模具加工提供了建构高品质CAD 模型的有效途径。

For example, we study the properties of the"centroid curve" and the"auxiliary curve", and identify two planes in which these two curves are defined respectively; we also use the idea of homotopy method to prove a fact that the orbit of a differential system has no triple contact point with the line we considered. Another key technique, which we use several times, is deformation argument.

例如研究由Abel积分之比定义的"质心曲线"和"辅助曲线"的几何性质，并把这两条在不同平面上定义的曲线放在同一坐标系中考虑；利用拓扑中同伦的思想来证明微分系统的轨线不可能与某条直线三重相切；利用几何方法与分析计算相结合证明了某一曲线是正则的；以及连续变动参数的技巧。

According to Xuzhou city relevant economic data for 1998-2004 year, this text,on the basis of environmental kuznets curve basic theories of the introduction, substantiates Xuzhou environment of economic development bearing capacity, which analyzes the necessity of economic development of circulation and adopts the economics method to explain the analysis result.

文章在介绍环境库兹涅茨曲线基本理论的基础上，根据徐州市1998-2004年的相关经济数据，实证分析了徐州经济发展的环境承载力趋势，利用环境库兹涅茨曲线分析了循环经济发展的必要性，并采用经济学的方法对分析结果进行了解释。

Temperature field of cross section, full curve under fire and related factors of them are analyzed.

5对轻钢-混凝土组合梁的抗火性能进行了研究：分析了截面的温度场及其影响参数；计算了构件的抗火全过程曲线，并分析了截面参数对全过程曲线的影响；采用抗力折减系数的方法研究了轻钢-混凝土组合梁承载力随受火时间的变化，并分析了各参数对抗力折减系数的影响

It has been put forward that there exists single Ball point and double Ball points on the symmetrical connecting-rod curves of equilateral mechanisms.

从鲍尔点的形成原理出发，分析对称连杆曲线上鲍尔点的产生条件，提出等边机构的对称连杆曲线上有单鲍尔点和双鲍尔点。

The factory affiliated to the Group primarily manufactures multiple-purpose pincers, baking kits, knives, scissors, kitchenware, gardening tools and beauty care kits as well as other hardware tools, the annual production value of which reaches US$ 30 million dollars.

集团所属工厂主要生产多用钳、烤具、刀具、剪刀、厨具、花园工具、美容套等五金产品，年生产总值3000万美元，产品价廉物美、选料上乘、质量保证，深受国内外客户的青睐