查询词典 symmetry

In topographic map, especially for city area, most of features are central symmetry and axial symmetry. By means of extracting features with symmetric figure first and then vectoring them according to their geometric characteristic, accuracy and efficiency can be increased and data sizes can be reduced.

在地形图中，轴对称和中心对称的要素占据着相当大的比例，特别是城市地形图中，房屋建筑等具有对称形状的要素占据了地形图中要素的绝大部分，在扫描图中首先对这些要素进行提取，进而根据特定要素的几何特征矢量化，可显著地提高矢量化精度和效率，减少数据的储存量。

The results show that, when the computational error and its accumulation are eliminated effectively, the laminar flow in OFR with perfect-symmetric boundaries behaves in a pattern of central symmetry and circumferential uniformity while the turbulent flow field presents a centrally symmetric and circumferentially non-uniform structure with 8 transverse vortices arrayed circumferentially in a way of central symmetry, similar to Taylor vortices in Couette flow.

模拟结果表明在有效消除计算随机误差以及误差积累的情况下，几何边界理想对称OFR内的三维层流流场呈现出良好的中心对称性和周向均匀性，而湍流流场中心对称的同时呈现出周向非均匀结构－在圆周上生成8个中心对称排列的横向漩涡，其形态与Couette流中的泰勒涡类似。

In DMMCS, there is an alternative distribution of inertial instability column and inertial stability column, at the west and south, there lie negative CVV columns, while negative CVV column is beneficial to deep moist convection.(4) The strong slantwise convection induced by inertial instability, baroclinic instability and conditional symmetry instability will enhance the upper level southerly component. Because of the appearance of the compensated downdraft at the low level of the south side of DMMCS, the low level southerly is intensified, the enhancement of upper- and low-level cores are in favor of the development of DMMCS. And that will do favor for the reinforcement and maintenance of inertial instability, baroclinic instability and conditional symmetry instability, it is a positive feedback process.

深湿对流系统中高层西侧为负MPV2 柱，东侧为正MPV2 柱；(3)深湿对流系统中惯性不稳定柱与惯性稳定柱相间分布，西侧为负CVV 柱，东侧为正CVV 柱，负CVV 柱对深湿对流起激发作用；（4）惯性不稳定、湿倾斜不稳定和条件不稳定产生强的倾斜式对流，而强的倾斜式上升运动加强了深对流系统北侧高层的南风分量，因深对流系统南侧低层出现补偿性下沉气流，因而低层南风加强，高低空急流中心的加强会进一步加强对流的发展，使得惯性不稳定、湿倾斜不稳定和条件不稳定增强和维持，这是一个正反馈过程。

Using finite difference time domain method, the electromagnetic field distribution of THz wave is simulated in a THz 2D PC splitter and by plane wave expansion method the dispersion relation and defect modes are achieved in a THz rotated PC waveguide.5. A woodpile three-dimensional (3D) PC with face-centered-tetragonal symmetry is one of the most popular 3D PCs because of its favorable band gap characteristics. Based on the woodpile fct lattice structure, we propose a novel woodpile THz lattice structure with comparatively decreased symmetry, better band gap properties and easy fabrication by varying some structure parameters.

计算结果为利用非线性光学差频方法产生THz辐射源的实验研究提供了深入和全面的理论基础；四、利用平面波展开法，通过改变二维THz光子晶体的结构参数，对二维THz光子晶体完全带隙进行了优化，分析出两种适合工作在THz波段的二维光子晶体结构；采用时域有限差分法和平面波展开法，计算出THz波在二维光子晶体"T"型分束波导，45度旋转波导中传输的电磁场分布以及缺陷模；五、Woodpile面心立方四角结构是三维光子晶体中被研究最广泛的结构之一。

The definite integral property in symmetry interval is extended to definite integral on non-symmetry interval and multiple integral.

在定积分和重积分中对对称区间上奇偶函数的定积分性质进行了推广。

In the forth stage, we use three features, that is, the triangle formed by eyes and mouth, the degree of the direction symmetry and the degree of the region symmetry to classify the facial orientations as three classes: frontal, oriented and non-frontal face.

过滤其它的线段后，找出线段中心分布密集的区域。再依据眼睛、嘴巴的相对位置、颜色特徵来找验证所找到的线段是否为眼睛和嘴巴所形成的。最后从找出的线段来推算出眼睛和嘴巴的位置。

With the method of the Lie group transformation,the symmetry of the equation governing one dimensional finite strain consolidation is discussed and,from the point of the symmetry,the feasibility to obtain the analytical solution of these nonlinear partial differential equations is discussed.

介绍了基于连续介质理论和混合物理论的大应变固结理论的发展，论述了两种一维大应变固结理论之间的差异及其一致性。

According to the complete geometric symmetry of the irons and windings, and the mirror symmetry during positive-negative operating-mode period, the expressions of current harmonics are derived, and the electromagnetic equitation are simplified. Based on this, the analytical calculation of flux density and the electromagnetic calculation of the reactor are performed.

根据两个铁心及绕组的结构完全对称以及它们工作状态在正负半周里呈镜像对称的特点，推导出电流谐波关系式，简化了本可控电抗器的电磁方程，并根据简化后的数学形式研究了其磁感应强度的解析计算，最终计算出了各项性能指标。

Flat surface is one rules the whole exact square, pillar net with medium stalk line or so and symmetry distribute, the symmetry decoration of the top and bottom floor studding son, whole is a shuttle pillar.

平面为一规整的正方形，柱网以中轴线左右对称分布，上下楼层间柱子对称布置，全为梭柱。

Its main features are: algae body as a single cell or even into a variety of groups; cell walls composed of silica and pectin, but also by the structure of the shell and the shell under the combined set of the Cheng, vertical section view was "soap-box"-shaped; in the upper and lower shell surface of the shell are patterns arranged in patterns on both sides of the main mode of symmetry and radial symmetry is divided into two categories, for the classification of the most important basis; be able to campaign Type in the shell has a shell side seam, can not be changed no shell seam types; pigment body sheet or ribbon, 1 or 2, or for multiple small discoid, yellow green or brown, containing chlorophyll a, c, also contains fucoxanthin and silicon A flavin and other photosynthetic pigments; storage material mainly for oil droplets; reproduction mainly for cell division and cell division in diatoms obvious features are: each cell division, resulting from two sub-cells,, only one and the mother cell and so big, the other one is smaller.

其主要特征是：藻体为单细胞或连成各式群体；细胞壁由硅质和果胶质组成，而且在结构上都是由上壳和下壳套合而成，纵断面观呈"肥皂盒"形；在上下壳的壳面上有花纹，花纹排列的方式主要分为两侧对称和辐射对称两大类，为分类上的最重要依据；能运动的种类在壳面都有壳缝，不能动的种类均无壳缝；色素体片状或带状，1个或2个，或为多个小盘状，黄绿色或黄褐色，含叶绿素a、c，还含有墨角藻黄素和硅甲黄素等光合色素；贮藏物质主要为油滴；繁殖方式主要为细胞分裂，硅藻的细胞分裂的明显特点是：每次细胞分裂所产生的2个子细胞中，仅有1个和母细胞等大，另1个则稍小。

The absorption and distribution of chromium were studied in ryeusing nutrient culture technique and pot experiment.

采用不同浓度K2CrO4(0，0.4，0.8和1.2 mmol/L)的Hoagland营养液处理黑麦幼苗，测定铬在黑麦体内的亚细胞分布、铬化学形态及不同部位的积累。

By analyzing theory foundation of mathematical morphology in the digital image processing, researching morphology arithmetic of the binary Image, discussing two basic forms for the least structure element: dilation and erosion.

通过分析数学形态学在图像中的理论基础，研究二值图像的形态分析算法，探讨最小结构元素的两种基本形态：膨胀和腐蚀；分析了数学形态学复杂算法的基本原理，把数学形态学的部分并行处理理念引入到家实际应用中。