扇形

The area bounded by a chord and the arc of a curve subtended by the chord.

弓形，扇形由弦正对的弦和弧线的弧所成的区域。

For the pentagonal, the fifth block fan-shaped, and the remaining three triangular rib angle plate on each side 4, edge angle plate 11 on each side; carapace brown, with three black longitudinal edges; shell and black, its edge angle plate with yellow; both sides of the carapace and the plastron to ligaments connected plastron in the chest, abdomen corner cubicle of the ligaments connected to the Trans-Yi Yi; means, and between the toes with webbed; tail short and pointed.

金钱龟的外型特征是头部光滑无鳞，鼓膜明显而圆；颈角板狭长，椎角板第一块为五角形，第五块呈扇形，余下3块呈三角形，肋角板每侧4块，缘角板每侧11块；背甲棕色，具3条黑色纵棱；腹甲黑色，其边缘角板带黄色；背甲与腹甲两侧以韧带相连，腹甲在胸、腹角板间亦以横贯的韧带相连；指和趾间具蹼；尾短而尖。

The fan-shaped batter brace on both sides of the bridge seem to be the chord-strings of a huge harp playing the bold and mejestic march for the ceaseless flowing water of the Huangpu River.

大桥两边的扇形斜拉索，颇似巨大的琴弦，在为那奔腾不息的黄浦江，伴奏着豪迈雄壮的进行曲。

A fan of black-chinned sparrow feathers captures the light.

一只扇形黑chinned麻雀羽毛捕捉轻。

Its translucent gills, in the sunshine, will show yellow-green, Gill, after a pair of pectoral fins, and other fish are not the same as the surface is a fan-shaped fins, and swimming up and is like a dance butterfly.

它的鳃半透明的，在阳光的照耀下，会显出黄绿色，鳃后是一对胸鳍，与其它的鱼不一样的是鳍面是扇形的，游动起来仿佛是一只翩翩起舞的蝴蝶。

The characters of directional blasting for demolishing the 120m chimney in Heshan Power Plant are that the toppling range is narrow （ a sector of +8 angle ）, the chimney's inner structure is not symmetrical in the toppling direction, the body's construction quality is relatively poor, and the engineering is very difficult with high risk.

广西合山电厂120m 烟囱定向爆破拆除的特点为倾倒方向范围狭窄（仅+8 扇形区），烟囱内部结构不对称于倾倒方向线，烟囱筒体施工质量较差，工程难度大、风险高。

On the basement of conventional direct fan-beam reconstruction, this paper gives a newly improved algorithm-"fast filtering-backprojection". This method utilizes the symmetrical circle geometry to sample projection data, and reconstructs image on the Polarcoordinate firstly, then translates this reconstructed image onto the cartesian coordinate system with two interpolating operations so that the computer can show the result image on the VGA screen. This algorithm rebates the calculating backprojection greatly, and shortens a few times of reconstructing time than same kinds of means. With the size of image enlarging, the reconstructing time abates with 2 exponent times. In addition, according to the idea of parallel-beam, we rearrange the fan-beams and reconstruct image using parallel-beam method fastly. The rearranging constraint condition is given here.

本文首先在传统的扇束直接重建方法的基础上，提出了一个改进的快速滤波反投影重建算法，它利用旋转采集投影数据的圆周对称的几何关系，先在极坐标系统内进行图象的重建，然后通过两次内插运算再将图象转换到计算机显示方式下的笛卡尔坐标系中去，该方法将以往的直接重建方法中的反投影时所需的运算大大降低，并将重建时间比同类方法缩短了几倍，而且随着重建图象的尺寸的增大，重建时间以2的指数次方倍相对缩短，并获得了较好质量的重建图象；另外，又根据平行束投影重建图象的思想，对扇形射束进行了重排，然后利用平行束重建图象的方法进行扇束的重建，并推导了&扇束重排重建图象&方法的约束条件。

The front composed of a shaped oval plaque with a circular cluster centre to scrolling ribbons and fan terminals suspended from a series of arched links intersected by five panels of similar design set throughout with circular-cut diamonds enhanced with baguette-cut accents.

正面是由许多圆形组成的一块椭圆形金属片，两侧为卷曲的缎带与扇形末端，悬挂自一系列拱形链环，间隔5个类似设计的部分，每一部分镶嵌圆形切割钻石，配以长方形切割钻石作为强调。

Its rich natural color, with the environment and the different venues can be any combination into a circular, square, fan-shaped, scale-shaped variety of different sizes and patterns.

其色泽丰富自然，随环境和场地不同，可任意组合成圆形、方形、扇形、鳞形等多种大小不同的图案。

The historical process of Xi'an University space expansion shows the characteristics of suburbanization, concentration, ring location, fan-shaped distribution, the multi-campus colleges and so on.

2西安市高等院校空间扩张过程中表现出郊区化、集聚性、环形选址扇形分布和高校多校区等特点。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。