三重对称轴
threefold axis of symmetry
常对称轴
common axis of symmetry
ordinary axis of symmetry
车辆轴重、轴距统计归纳方法
statistical and summarized method for axle load and wheelbase of vehicle
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