This paper considers the relationship between the twofold element for plane projective transformation and characteristic root of transformation matrix,and points out the existing conditions of the twofold point(the twofold line) and the twofold point range(the twofold line pencil).
研究了二维射影变换的二重元素与其变换矩阵的特征根之间的关系,指出了在什么条件下出现二重点(二重直线),在什么条件下出现二重点列(二重线束),探讨了二重点与二重直线之间的内在联系。
Thus the finite element method is used to study the duplex nonlinearity(geometric nonlinearity and contact nonlinearity)of the drill string at the well bottom.
针对以上难题,利用有限元法研究了钻柱在井底的二重非线性(几何非线性和接触非线性)问题。
Quality Problems and Reason Analysis of Double Duo Wire Mill;
复二重线材轧机产品的质量问题与原因分析
double generator of a ruled surface
直纹曲面的二重母线
That is what a double helix looks like.
这就是二重螺旋线的形状。
single coil double-tuned NMR probe
单线圈二重调谐核磁共振探头
Two Peaks of 3D Structure Constructed by 2D Contour Lines;
利用二维轮廓线重构双峰值三维形体
Uniform duplicate mixed hyperbolic polynomial B-spline curves
均匀二重混合双曲多项式B样条曲线
They found that each molecule of D-N-A is in the shape of a double helix.
他们发现每个DNA分子都是二重螺旋线形状，
Each step of the double helix is a base made up of two kinds of nucleic acid.
每阶二重螺旋线都是一个碱基，由两种核酸组成。
Recovering the Geometry of Single Axis Motions by Conic Fitting;
基于二次曲线的单轴旋转运动分析和三维重建
Multiple Positive Solutions of Nonlinear Singular Second-order Three-point Boundary Value Problems;
奇异非线性二阶三点边值问题的多重正解
A Subdivision Method Reproducing Conics with Non-uniform Data;
非均匀控制点重构二次曲线的细分方法
Multiplicity of Positive Solutions to Singular Superlinear Second-order Periodic Boundary Value Problems;
奇异超线性二阶周期边值问题的多重正解
Multiplicity of Positive Solutions to Singular Superlinear Equations with Neumann Boundary Value Problems;
奇异超线性二阶Neumann边值问题的多重正解
Moderate Deviations Principle and the Law of the Iterated Logarithm for LSE in Linear Models;
线性模型中最小二乘估计的中偏差及重对数律
Analysis and Strategy for Insecurity Factors in No.2 Line of Chongqing Light Rail Transit;
重庆轻轨二号线运营不安全因素分析及对策
Nonlinear Rescaling Methods for Nonconvex Second-Order Cone Programming Problems
非凸二阶锥规划问题的非线性重新尺度化方法
RF PIN Diode Switch in Reconfigurable Antenna
PIN二极管在可重构天线中的作用的研究
Linear Bi-level Multi-follower Fractional Programming Problems
一类具有多重二层决策的线性分式双层规划