arciform

In this paper, we show a formula for the arciform area enclosed with a parabola and a straight line by means of two kinds of clever separation and the knowledges of elements mathematics such as the sum formula of infinite decreasing geometric sequence.

文章运用两种巧妙的分割和利用无穷递缩等比数列求和公式等初等数学知识，求出了抛物线与相交直线围成的弓形面积计算公式。

The southern Ningxia ′ s arciform structure zone, extending 150~ 300km, consists of four great arcuate thrust nappe structural belts with a convex toward the northeast.

宁夏南部弧形构造带主要由四大弧形推覆构造带组成，总体走向NW，凸向NE呈弧形展布，延伸150km～300km。

The arch axis of arciform aqueducts formed by the continuum topology optimization method was compared with the circular arch axis and the parabolic arch axis of the same span.

结果表明，由结构拓扑优化方法生成的拱轴线，自重作用下的弯矩值以及相同均布荷载作用下的应力值都比相同矢跨值的圆弧拱轴线和二次抛物线拱轴线小。