平行直线

The surface generated by a straight line intersecting and moving along a closed plane curve, the directrix, while remaining parallel to a fixed straight line that is not on or parallel to the plane of the directrix.

柱面一条直线与一个封闭的平面曲线相交及沿着平面曲线移动所形成的平面，准线则与一个不在此准线平面上或者不与此准线平面平行的固定直线保持平行

The series are using for flat glass grinding, and parallel straight line pencil edger rough grinding,fine grinding and polishing finishing at one time.

该系列产品适用于对平板玻璃的磨边加工，可同时对玻璃的两条平行直线圆弧边的粗磨、精磨一次加工完成。

Say for example, when discussing on parallel axiom, which is "given a point and a line on a plane, there exists a unique line on the plan that passes through the point and is parallel to the line", if we change the axiom as "there is not any or there are infinitely many lines that will pass through the point and be parallel to the line", then we have two kinds of non-Euclidian geometry.

就像对于平行公理的讨论一样，干脆规定：过已知直线外一个固定点可以作无数条与已知直线平行的直线；或者过已知直线外一个固定点的任何直线都不能与已知直线平行；这样还产生了两个版本的非欧几何。

If the images are two parallel lines, it will be two parallel linea...

如果图像中有两条平行的直线，则将这两条平行直线*提取出来。

If the images are two parallel straight lines, they will be two parallel straight lines extracted.

如果图像中有两条平行的直线，则将这两条平行直线提取出来。

Andrews' Pitchfork is an instrument consisting of three parallel Trend Lines.

条平行直线的趋势线，由安德鲁博士最先发现。

The main contents include the ray phenomenon and its generation conditions; the deduction and physical illumination of wave action conservation equation and wave number conservation equation; ray theory for sinusoidal waves; Fermat's principle; the variation of amplitude in the case of straight and parallel depth contours and circular depth contours; the amplitude near the caustics; wave trapping; deduction of mild-slope equation and the relevant numerical solution methods.

讲授折射现象及其发生的条件；波作用守恒方程和波数守恒方程的推导及物理解释；稳恒正弦波的控制方程及射线方程；费马原理；利用射线方程研究等深线是平行直线和圆周线时波振幅的变化，特别是焦散线附近波高的变化以及由此而产生的波的俘获；缓坡方程的推导及有关的数值求解方法。

A vanishing point or a vanishing line indicates the direction information of a s et of parallel lines or a set of parallel planes.

消失点或消失直线蕴含了一组平行直线或一组平行平面的方向信息。

The special geometric restrictions like parallelism andperpendicularity implicated in vanishing elements are deeply studied. In single-view case,the theory is presented to interpret relationship between two planar lines by applying 3Dinvariants of vanishing points. In two-view case, the method on extraction vanishing pointof an arbitrary spatial line is described, and moreover, the theory is presented to interpretrelationship between two elements in 3D space, such as two lines, two planes, line andplane, and so on.

4详细论述了消失元素(消失点、消失直线、消失平面等)所体现的垂直、平行等特殊几何约束关系；对单视图，提出了一种利用消失点列的3D不变量解释平面直线关系的方法；对双视图，提出了利用自共轭三角形和对极几何约束，提取任意直线的消失点的算法，并在此基础了提出了一种利用消失元素的3D不变量解释直线间、直线与平面间、平面间等多种空间几何关系的方法。

First of all, this paper derives pressure expressions of stable state about vertical well inanisotropic media with various boundary. Based on this, Formulae of pressure distributionfor five-spot pattern and nine-spot pattern have been established, the characters of isobariccontours and streamline are analyzed, and this equips optimum of well pattern with theoreticfoundation.

首先利用坐标转换及镜像反演理论，推导了单一直井直线边界、平行直线边界的定常渗流的压力分布公式，在此基础上研究了五点法井网、九点法井网定常渗流问题，推导了压力分布方程，分析了等势线及流线的特点，为各向异性储层井网优化提供了理论基础。

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