查询词典 symmetry axis

Distribution of luminous intensity having an axis of symmetry or at least one plane of symmetry.

对光源而言，至少有一轴对称或面对称的光强分布。

Application of both finite element and combined strip element to axis symmetry problems;2. Basic definition of axis symmetry has been given with three specific examples.

通过三个例子讲述了折叠矩形后满足轴对称的基本定理，并分别从折叠一次、两次介绍了折叠型的解题方

This article according to the function image axial symmetry and the point symmetry basic principle,the use function taylor series expansion,determines and seeks the polynomial function image the axis of symmetry or the center of symmetry.

根据函数图象轴对称及点对称的基本原理，利用函数的泰勒级数展开式，来判定和寻找函数图象的对称轴或对称中心。

Secondly, three kinds of mathematics model of optical vortex beams were introduced here. Then the propagation dynamics of optical vortex beams through the non-axis symmetry system is studied, this chapter includes the introduction of the symmetry vortex beam and the non- symmetry vortex beam, the deduction of the Collins diffract integral formula for the non-axis symmetry system, and the transformation of the vortex beam passing through the non-axis symmetry system has been described by using the numerical simulation. Then the general calculation for the orbit momentum of vortex beams, the matrix form for the orbit momentum of vortex beams, and the photon method to describe the orbit momentum of vortex beams are also introduced here. Finally, the interference about optical vortex beams was studied.

本文对涡旋光束进行了较为全面的介绍和研究，主要内容包括：（1）光学涡旋光束的基本理论，主要是介绍了单个光学涡旋光束在柱坐标中的一些表征，涡旋光束的奇异相位和光学涡旋的相位结构；（2）光学涡旋光束的三种数学模型；（3）光学涡旋光束在非轴对称光学系统中的传播动力学，其中介绍了对称涡旋光束与非对称涡旋光束，推导了非轴对称光学系统的 Collins 衍射积分公式，并利用计算机模拟图描述了对称涡旋光束经过非轴对称光学系统后涡旋形态的改变；（4）涡旋光束轨道角动量的一般计算，涡旋光束轨道角动量的矩阵形式，光子法描述涡旋的轨道角动量；（5）涡旋光束的干涉。

Hence, an analysis method of long-spread nonhyperbolic normal-moveout velocity for P-wave in weak transverse media with vertical symmetry axis is illustrated. The quartic term of the Taylor series expansion for t2-x2 curve is used to determine the normal-moveout velocity.

文中阐述了横向各向同性介质中长排列的非双曲线的P波时差速度分析方法，即对P波的旅行时间进行泰勒展开，应用t2～x2的四次方展开项进行时差速度分析。

A wind- and motor-powered land vehicle with a fore-and-aft longitudinal axis comprising a body supported by wheels, at least one of said wheels fixed to rotate in a plane parallel to the fore-and-aft axis of said vehicle, an airfoil system comprised of two vertically extending airfoils rigidly mounted on said body in an arrangement having bilateral symmetry about a vertical plane through said fore-and-aft axis, said airfoil system providing a forward propelling force of said vehicle when the airfoil system is subjected to certain cross wind conditions, and self-contained motor propulsion means on said vehicle for providing acceleration from a stationary position and for propelling the vehicle either independently or in combination with propelling forces generated by wind action on said airfoil system, each airfoil having a plurality of airfoil sections telescopically fitted together, the lower airfoil section being rigidly mounted in fixed relationship to said body, said airfoil system including a retracting mechanism for lowering upper airfoil sections of said airfoil system when desired and for subsequently extending said airfoil system, said retracting mechanism including a plurality of linkages interconnecting said sections and an actuator means operatively connected between said body and to said linkages for lowering and extending each airfoil, and an intermediate airfoil extending between the upper sections of each of said airfoils so as to provide an inverted U-shaped airfoil.

风力和电动机驱动的陆地车辆与前列和尾部长轴组成的一个机构的支持，车轮，至少有一说，车轮固定在一个旋转平面平行的前列和前后轴的说，车辆，翼型系统组成的两个垂直扩展翼型硬性安装在说，机构在安排后，双边对称约一垂直面说，通过国内外和前后轴，表示翼型系统提供了一个向前推进的力量说，车辆时，翼型系统是受到某些横风条件下，和自我载电机推进的手段就表示，车辆提供加速从一个固定的立场和为推进车辆单独或结合，与推进力量所产生的风的行动表示翼型系统，每个机翼有一个多元化翼型第telescopically装在一起，较低的翼型节被硬性安装在固定的关系，说身体，说翼型系统包括一个撤消的机制，降低上翼型章节说，翼型系统时，理想的和其后再将说，翼型制度，说收回机制包括多元化的联系互连说，部分和一个致动器的手段手术之间的连接说，身体和说，联系降低，并延长每翼型，及一个中间翼型延长之间的路段上的每说翼型，以便提供一个倒U -形翼型。

First, the color-image was preprocessed with grayscaling, smoothing. The vertical gradient components of the image were found using the vertical mask of Sobel operator. Then the candidate areas with sufficient amount of edges were determined by calculating the gradient of edges. After finding possible vehicle candidates, the proposed method measured the prominent vertical symmetry of candidate areas and verified all possible candidates, as symmetry is an important feature of vehicle. The proposed method also figured out the vertical axis of symmetry and the width of the candidate vehicle.

算法首先对图像进行灰度化、平滑去噪等预处理，使用Sobel算子垂直方向掩模计算图像感兴趣区域内的边缘梯度，确定候选区域；而后根据车辆图像垂直边缘具有对称性的特点，分析候选区域的对称性强弱，并计算其对称轴位置和车辆宽度。

During the infiltration process of indirect subsurface drip irrigation, the ponded water depth changed from zero to a constant and accelerated the water movement in the vertical direction, which reduced the discrepancy of wetted distance in lateral direction and vertical direction, while the changed water depth had small influence on the wetting front movement in vertical direction to upward and downward. The shape of wetted soil zone was spheroid, and its symmetry axis lied near the bottom of the water conducting device.

间接地下滴灌灌水过程中，从零开始逐渐增大并趋于稳定的积水深度加速了水分在垂直方向的运移，缩小了横向湿润距离和垂向湿润距离之间的差异，但变化的积水深度对湿润锋在垂直方向向上和向下的运移速率影响不大，使湿润体形状表现为扁率不断减小的椭球体，且椭球体对称轴分布在靠近导水装置底部的位置。

Symmetry axis and the mercy of the 14 totem pole totem pole is the re-emergence of the Han Dynasty.

而以中轴线对称摆布的14个图腾柱则是汉代图腾柱的再现。

Their ability to draw the picture accurately is impaired especially when the symmetrical axis is tilted. Parallelograms are easily mistaken for line-symmetry diagrams. Point-symmetry diagrams tend to prevent correct identification of line-symmetry diagrams.

学童在画线对称图形另一半的能力有待加强，尤其当对称轴是歪斜时会影响学童画图的准确性；平行四边形易被当成线对称图形，点对称图形也会干扰线对称图形的判定。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。