[轴的]对称度
degree of symmetry [of the axis
常对称轴
common axis of symmetry
ordinary axis of symmetry
次对称轴
secondary axis of symmetry
单轴对称工字形截面
nonsymmetrical I-sections
单轴对称截面
single symmetric section
singly symmetric sections
等轴对称半面像晶类
cubic enantiomorphic hemihedral class
二维轴对称
2-dimensional axis symmetry