用一个重正化函数F z F bz /a 作为支气管结构第z 个层次 的半径则参数b 表征了对半径变化有贡献的标度区间的测度而a 表 示某个特征标度的权重-with an emphasis of function F is F bz z / bronchial structure as a first level of z radius parameter b is characterized by changes in the radius can contribute to the s