由法线面上渐近线条件确定的2种特殊螺旋线

Two types of helices determined under the conditions of the asymptotic curves on normal surfaces

在螺旋线的法线面上,由2条特殊曲线成为渐近线的几何条件得到2种特殊螺旋线.

Two types of helices are obtained under the conditions that two special curve become asymptotic curves on their normal surfaces,respectively.