几何形体重构
geometric shape reconstruction
盐体几何形态
geometric shape of salt body
可重复排列
thought and formula of permutation with repetition
可重复排列与可重复组合
permutation and combinations with repetition
无重复排列
permutation without repetition
重复排列
permutation with repetition
repeated permutation
表面几何形状
the geometry shape of surface
槽形几何参数
spiral groove ’s geometric parameters