As weapons of long shot, bow and arrow had bright moments in history.
本文主要针对《考工记》中《弓人》、《矢人》两章,对上古弓箭制作工序的相关问题进行探讨。
Research on water flooding effect improved by vectorial well arrangement for reservoirs with permeability heterogeneity in plane;
矢量井网改善平面非均质油藏水驱开发效果研究
Random Directive Vector Dimension Chain and Its Application in Machine Tool Design and Manufacture;
随机方向矢量尺寸链及其在机床设计制造中的应用
The maps for different nonlinear parameters under the condition of fixed wave vector are calculated,and the corresponding evolution of the square of wave displacement along the nonlinear superlattice is also numerically calculated.
通过二维实映射研究非线性Kronig Penney超晶格中的波输运特性 ,数值计算得到波矢一定情况下不同非线性系数的映射图、以及非线性系数一定情况下不同波矢的映射图 。
The g_l dimensional representation of the wave vector group is induced by the basis of the irreducible representation of the translation group.
由平移群的不可约基诱导波矢群G(kω)的一个gl维表示,通过构造G(kω)表象群G′k,利用本征函数法将gl维表示约化,得到G′k的IR基,利用G′k可将求波矢群G(kω)的IR问题转化为求表象群G′k的IR问题。
The maps for different nonlinear parameters under the condition of fixed wave vector are calculated, and the corresponding evolution of the square of wave displacement along the nonlinear superlattice is also numerical calculated.
非线性K P超晶格中的非线性 ,对超晶格中波函数的Bloch波矢有明显的调节作用 。
Regulating Effects of Lanthanum on Physiological Response of Pseudosasa japonica Leaf to Mercury Stress;
镧对汞胁迫下矢竹叶片生理反应的调节
Based on above mentioned,it is quite convenient to compute point vector and normal vector.
复杂形状零件的几何建模是数控编程的首要环节,选择合适的曲面造型方法有利于刀位计算和数控加工编程;本文采用三次B样条曲线为基础的双三次B样条曲面造型方法,并给出了其矩阵表达式,在此基础上能十分方便地进行点矢和法矢计算;针对该造型方法,还给出了三轴数控加工中的刀位数据计算方法。
In the algorithm, normal vector and curvature are first calculated according to the point and its neighbor points, and then normal vector of every point is oriented to the outside of the surface.
提出一种以物体表面上不附加任何几何和拓扑信息的散乱点集为处理对象,自动进行点云数据配准的算法·该算法针对待配准的2组点云数据,根据测点及其邻域点估算每个点的曲面法矢,并对法矢方向进行调整,使其指向曲面的同一侧;然后计算各个测点的曲率·根据每个测点的曲率来识别出2组点云数据中可以匹配的点对集合,计算将每一个点对的法矢方向映射为一致的三维空间变换,采用几何哈希方法找出使得最多数量的点对法矢一致的变换,运用该变换将散乱点云作初次配准·以初次配准后的结果作为新的初始位置,将匹配点对集合中的所有点对采用最近点迭代法进行二次配准,从而实现了2组散乱数据的精确配准·应用实例表明,该算法效果良好
Combined with the engineering example, the computing formula and method are analyzed from many aspects, such as the values of axis, arc length, chord length and vector height and other key elements.
框架 -剪力墙曲面结构建筑物的施工 ,梁、板、墙等各种曲面的控制尤为关键 ,结合工程实例就其轴线、弧长、弦长、矢高等要素在施工过程中 ,对其计算公式的确定与方法进行了分析。