挠曲线

The impression cylinder of J2108 offset press is regarded as research object in paper,and the deflection of cylinder is researched as simply supported beam with variable cross section .

以J2108型胶印机压印滚筒为研究对象，将滚筒挠曲变形作为变截面简支梁问题来研究，考虑重力载荷影响，通过积分法得到滚筒在印刷压力和重力载荷作用下的挠曲变形方程和曲线，应用MATLAB7.0平台上编写了印刷滚筒挠曲变形计算程序，为滚筒结构的合理设计提供了依据。

Properties of Curves, Surface in Three Dimensions, The First Fundamental Form

课程内容：平面与空间中曲线，曲率和挠率，全曲率，同周边不等式，曲面的基本式，平

For the application of Mathematica in the differential geometry,this paper introduces how to processe the curve curvature and the torsion questions,the graphic expression of the curvature and the torsions,and draw curves by the curvature and the torsions. Curvature ; torsion ; solution curve ; osculating plane ; natural parameter ; natural equation

利用Mathematica，只要输入有关系统命令就可以得到期望的结果。1曲率和挠率及其图形意义假设R3上的曲线一般参数表示为r=r它的曲率和挠率计算公式是：κ=‖r′×r"‖‖r′‖3τ=‖r′×r‖我们知道，空间曲线r=r在一点(s=s0)邻近的近似方程为ξ=sη=120κs2ζ=160κ0τs3通过近似方程可以确定曲线在其基本三棱形的三个平面(即密切平面，法平面，从切平面)上的投

In this paper a framework is built for differential quantity calculation on spatial curves of point cloud and a new matching method for given point curves is proposed.

建立了点云几何分析的相关理论框架，即定义和计算点云潜在曲线的几何微分量，包括Frenet标架、曲率、挠率等；在此基础上提出一种新的点云空间曲线匹配方法。

Finally, a method is developed for detecting feature points of the fragment con-tour based on total curvature.

将曲率和挠率相结合得出轮廓曲线上各点的全曲率，然后由全曲率值来检测碎片轮廓的特征点。

In order to reduce the cost of matching, we used multiple scale technique. 4. We presented a novel method of searching for similar fragments of 3D curves. with this method, a hash vector is associated with each fixed-length fragments of 3D sherd. Each vector consists of low frequence component of Fourier-Like spectrum for the distance between profile curve and the centroid.

依据样条曲线的基本理论，研究了基于B样条的轮廓曲线的匹配方法，给出了由轮廓曲线不变量曲率和挠率构造的相似不变量的选取以及基于相似矩阵的匹配算法，并对该算法的时间复杂度作了估计，同时，将多尺度技术引入到物体轮廓的匹配问题中。

The curve continual steel box Liang shearing force stagnates the effect finite element analysis box section Liang has the big flexural rigidity and torsional stiffness, the stress performance good, spanning ability big, on the bridge the field of vision open and so on the merits, is in the bridge design the commonly used structural style, when receives under the dead load or the symmetrical live load function winding, because the lifting surface detrusion causes its bending stress to present the non-uniform distribution condition along the Liang width direction, this phenomenon is called "the shearing force to stagnate the effect".

曲线连续钢箱梁剪力滞效应的有限元分析箱形截面梁具有较大的抗弯刚度和抗扭刚度、受力性能好、跨越能力大、桥上视野开阔等优点，是桥梁设计中常用的结构形式，在受恒载或对称活荷载作用下挠曲时，由于翼板的剪切变形致使其弯曲应力沿梁宽度方向呈现不均匀分布状态，此现象称为&剪力滞效应&。

The estimation of forming part"s sideline The estimation of forming part"s sideline is significant in weld and assembly process, the paper puts forth two kinds of method to realize quantitative analysis for the deformed sideline, one is using line contour error to estimate deformed sideline combined with GA and taking the value of line contour error as target to check whether it is in the range of precision; The other is comparing curvature and torsion of design model with curvature and torsion of deformed model to check the sidelines precision.

冲压件边线变形的评价。冲压件的边线变形的评价在焊装工艺中有着重要意义，本文提出两种方法来实现冲压件边线的变形评价：一是借鉴线轮廓度评定的方法，结合遗传算法计算出边线的线轮廓度，并以线轮廓度值作为边线是否满足要求的评价指标：二是通过比较变形前后曲线的曲率和挠率来评价边线的变形情况。

According to the objective of third-order derivative related to torsions, the formula to calculate the cubic optimized Hermite interpolation curves is given. And then we propose a new method to construct curves.

如果以与挠率有关的三阶导数为目标，给出优化三次Hermite曲线的计算公式，从而提出一种新的曲线构造方法。

For the application of Mathematica in the differential geometry,this paper introduces how to processe the curve curvature and the torsion questions,the graphic expression of the curvature and the torsions,and draw curves by the curvature and the torsions. Curvature ; torsion ; solution curve ; osculating plane ; natural parameter ; natural equation

利用Mathematica，只要输入有关系统命令就可以得到期望的结果。1曲率和挠率及其图形意义假设R3上的曲线一般参数表示为r=r它的曲率和挠率计算公式是：κ=‖r′×r&‖‖r′‖3τ=‖r′×r‖我们知道，空间曲线r=r在一点(s=s0)邻近的近似方程为ξ=sη=120κs2ζ=160κ0τs3通过近似方程可以确定曲线在其基本三棱形的三个平面(即密切平面，法平面，从切平面)上的投

Chrysanthemum of 10 thousand birthday is lax to edaphic requirement, with the arenaceous qualitative loam with fecund, good drainage had better.

万寿菊对土壤要求不严，以肥沃。排水良好的砂质壤土为好。

He unstepped the mast and furled the sail and tied it.

他拔下桅杆，把帆卷起，系住。