三叶形

It was found that fibers of circular cross section produce greater cohesion in webs and slivers than do trilobal fibers.

圆面纤维在棉和棉条中，比三叶面纤维能产生较大的粘着作用。

"The Bar tracery of the parallel English Decorated style formed netlike patterns Based on the circle, arch, trefoil, and quatrefoil."

平行的英国装饰风格的条窗花格以圆圈、拱、三叶和四叶为基础,成状图案。