圆和

Then three candidate modulation schemes exploiting spatial dimensions are proposed. At last, the three modulation schemes are compared by power efficiency and bandwidth efficiency. It shows that spatial quadrature amplitude modulation scheme is appropriate for long distance wireless optical communications for its high bandwidth efficiency and spatial circular symmetry.

参照传统时域信号设计方案，提出了三种空间调制信号具体设计方案，并从带宽效率和功率效率两性能上进行了比较，结果表明正交幅度调制具有带宽效率高、功率效率低的特点，而且采用的信号点越多其带宽效率就越高，另外其空间信号图案还具有圆对称性，因此非常适合在空间带宽有限的远距离无线光通信中使用。

Using plane wave circular aperture diffraction as an example, this researchstudied the changes ofηwith diameter of diffraction holeρ_0, propagation distance zand light spot radius r and found how to obtain the largest energy concentration degree by controlling these three factors.

本课题以平面波圆孔衍射为例，研究了光束能量集中度随衍射孔径ρ_0、传播距离z和光斑半径r的变化规律，并指出如何控制这三个因素来获得光束的最大能量集中度。

Complex method and multi-polar coordinate transformation are used here to study the scattering problem of SH -wave to the circular cavity in the half-space with elastic constraints acting on the straight boundary.

利用复变函数法和多极坐标移动技术求解讨论弹性约束边界半空间内浅埋圆孔对稳态入射平面SH（shearing horizontal，反平面剪切）波的散射问题。

With the application of the symmetry of line and circularity, the speed of the generation of a whole compass screen is highly advanced.

利用直线对称性和圆的对称性，提高了全罗盘画面的生成速度。

Area and circularity act as two elements of the eigenvector for they can remarkably characterize the surface area of the bubbles.

由于分类的依据是气泡表面积的大小，确定了圆面积和圆形度两个最能表征类圆形表面积的分量组成分类特征向量。

The optimization algorithms are commonly used to approach the minima of the roundness objective functions through iteration when a microcomputer is applied to assess roundness errors by minimum zone, minimum circumscribed circle, and maximum inscribed circle methods.

引言在用计算机求最小区域、最小外接圆和最大内切圆评定法求圆度误差时，广泛采用最优化算法，通过迭代去逼近目标函数的极小值。

The details as follow: 1.Based on rules about form error in GB, mathematical models of form error are established including straightness error on the base of minimizing zone method、least-squares method and two dots linked method ; flatness error based on minimizing zone method、lease-squares method、diagonal line and three dots method; circularity and cylindricity error based on minimizing zone method、lease-squares method、minimum circumscribed circle and maximum inscribed circle.

具体内容如下：根据国标中形状误差的相关规定建立了各种要素评定方法的数学模型包括：直线度的最小区域法、最小二乘法、两端点连线法；平面度的最小二乘法、最小区域法、对角线法、三远点法；圆度和圆柱度的最小区域法、最小二乘法、最小外接圆法、最大内切圆法。

The original Jinpeng Hardware Tools Factory, after years of efforts and continuous innovation, and now owns the right to export, the company owns the domestic advanced production lines of two, three million annual production, annual production value of 1,000 million yuan, mainly the production of high-, mid-range Claw Hammer, round Mace and tools of woodworking products, product quality, delivery timely, Product perennial subject of praise from domestic and foreign merchants.

是原金鹏五金工具厂，经过多年的努力和不断创新，现已拥有自营出口权，公司拥有国内先进的生产流水线2条，年产量300万只，年产值1000余万元，主要生产高、中档羊角锤、圆头锤及农具木工产品，产品保证质量，供货及时，产品常年受到国内外客商的好评。

Total genomic DNA was extracted from four marine fishes (Verasper variegates, Cleisthenes herzensteini, Turbot Scophthalmus maximus, red seabream Pagrosomus major) using a proteinase K and phenol-chloroform procedure. Long mtDNA fragments were amplified by long and accurate PCR using primers designed based on the mtDNA sequenses of Thunnus thynnus thynnus, flounder Paralichthys olivaceus and other related fishes.

用蛋白酶k酚氯抽提法从圆斑星鲽、高眼蝶、大菱鲆和真鲷4种海水鱼的肌肉组织中提取基因组DNA，根据金枪鱼、牙鲆及相关鱼类的线粒体DNA序列保守片断设计出扩增引物，扩增从16SrRNA到ND4之间约9400bp的mtDNA长片段。

We obtain the theorem of closed ball case in the continuous probabilistic metric space and the complete character theorem of Menger space.

以及球笼式等速万向节的偏心距与钢球中心圆半径之比进行了优化选择和比较。

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