查询词典 concave curve

The characters of the singular point of the visible contour line of a concave rotative surface and its corresponding projection are analyzed on condition that the projection of the contour line is smooth near the singular point , the shape of the visible contour line of a concave rotative surface near the singular point is further studied.

对凹回转面可见轮廓线的投影在奇点附近仍光滑的情况下，分析了可见轮廓线本身与奇点对应点处的曲线特征以及可见轮廓线在其对称平面的投影图上与奇点对应的点的特征。对凹回转面可见轮廓线在奇点附近形状作了进一步的分析与研

A grating function and a groove function are introduced to determine the structure of a concave grating. Basic ideas for the design of a flat-field concave grating with three stigmatic points are proposed. As a proof of the usefulness of these design approaches, image conditions of the grating with three stigmatic points are developed which concise with other published results and they are more general than those obtained from holographic gratings.

采用与分析三维光栅相类似的级数展开法给出了二维集成凹面光栅的球差、彗差的计算方法，计算中用光栅函数和槽面函数来描述具有任意形状和任意变化周期的光栅，提出了一种具有三个无像差点的平面场型凹面光栅的设计方法，利用该方法推导了三点无像差光栅的成像条件，与文献中用其它方法获得的结果相一致，该结果与全息光栅的成像条件相比，更具一般性。

Holographic concave gratings with three stigmatic points can be implemented through considerable design. Results obtained from holographic gratings can also be applied to ruled gratings. Sphere and coma aberrations for a planar concave grating are achieved through power expansions.

通过适当的设计，可以使得全息光栅具有三个无像差点，这些分析虽然是针对全息光栅而得到的，但通过记录参数的合理选择可以将其应用到刻划光栅中去，得到等价的刻划光栅的参数。

The thickness of the ice cover on the wall surface heat transfer is greater than the thickness of it on the air heat transfer form. The thickness of the ice cover on the wall surface heat transfer along the way changes slowly, but it on the air heat transfer along the way changes significantly. Reducing the entrance velocity, lowering the wall surface or air temperature, the formation of the thickness of the ice cover will increase; in the 3D circumstances, The thickness of the ice cover was relatively uniform in the import of the U-turn model, the ice cover was gradual accumulation in the convex bank when the stream traversed the import of the U-turn model, the thickness of the ice cover in the convex bank was significantly bigger than the thickness in the concave bank. The temperature field under the ice cover tends to be complex because of the existence of the secondary flows. The temperature in the convex bank is greater than it in the concave bank. Compared with the data from experiments, the laws in the numerical simulation are similar with them in the experiments

模拟结果显示：二维情况下，运用壁面传热形成的冰盖厚度大于运用空气传热形成的冰盖厚度，壁面传热形成的冰盖厚度沿程变化缓慢，而空气传热形成的冰盖厚度沿程变化明显，减小入口流速，降低壁面或空气温度等，形成冰盖的厚度都会增大；三维情况下，弯道入口处凸、凹岸形成的冰盖厚度基本相同，进入弯道后，凸岸形成的冰盖厚度逐渐增大，而凹岸的冰盖厚度逐渐减小，受横向环流的影响，冰盖下水流的温度场趋向复杂，并且凸岸的温度小于凹岸的温度；与实验室实验所得数据相比较，数值模拟研究得到的规律基本符合实验规律。

The computation analysis indicates that increasing the aperture of the concave focusing transducer, decreasing it's geometric focal length or raising it's central working frequency can improve the transverse and axial resolutions of the system simultaneously, but changing the dividing proportion of the transducer affects the two kinds of resolution differently. On compromisingly considering several factors including the exciting mode, the focusing ability and the radiation force effect, the concave focusing transducer should be divided into two equal-area parts.

计算研究表明：增大凹球面换能器的口径、减小几何焦距和提高中心频率均可以提高系统的侧向分辨率和轴向分辨率；但改变凹球面换能器的分割比例对两种分辨率影响不尽相同综合考虑超声换能器激励、聚焦性能以及产生的辐射力效果等因素，则换能器应按等辐射面积原则分割为宜。

The emanative ligth shooted by the small bulb which is put at the focus of concave mirror is turn into parallel light by reflecting of concave mirror.

放在凹面镜焦点处的小灯泡发出的发散光经过凹面镜反射变成平行光，这说明在光的反射现象中光路是可逆的。

Glass and its products: watches and glasses presenting arc, curved and concave shape, glass without optics-processing presenting arc, blending and concave shape and some unlisted and without optics-processing but presenting arc blending and concaved shape.

玻璃及其制品：呈弧面、弯、凹等形的钟表、眼镜，其他未经光学加工呈弧面、弯、凹，未列名未经光学加工呈弧面、弯、凹等形玻璃。

CONVEX-CONCAVE SHAPE:Unique designed of convex-concave shape,which can strengthen and expand the heated measure.

在省油器表面形成许多凹凸面：使表面受热面积加大，促进吸收光能及热能，增加红外线放射能量。

Quasi-convex relaxation algorithm, which aims to solve ordinary constraint global optimization problems, is produced by a combination of branch-and-bound method with quasi-convex lower bound and quasi-concave upper bound functions developed from quasi convex-concave extension. This algorithm extends the interval algorithm with box constraint to general constraint global optimization problem.

利用拟凸-凹扩张中构造出的函数的拟凸下界函数和拟凹上界函数，与分枝定界方法相结合，建立了求一般约束全局优化问题的拟凸松弛算法，这一算法是将盒子约束的区间算法推广到一般约束优化问题中。

Considering the triangulation algorithm based only on the determination of convex-concave vertices is restricted to simple polygons, this paper presents a triangulation algorithm for the general plane polygon GTP(General Triangulation of Polygons) based on determination of convex-concave vertices and connecting the outer border of a polygon with its inner borders.

摘 要：针对基于凹凸顶点判定的三角剖分算法适用范围有限的缺点，提出了将凹凸顶点判定与连接多边形内外边界相结合的适用任意平面多边形的三角剖分算法GTP(General Triangulation of Polygons)。

Combining the testing accuracy of different kernel functions, an optimal kernel function is obtained to solve this problem.

综合各种核函数的测试准确率，得到解决该问题的最佳核函数。

One day, we went to daniel's friends house, he lives in the east bay.

有天我们去 Daniel 的朋友家，他住在东海岸。