Let p(n) denote the smallest prime factor of n > 1.
设ｐ（ｎ）表示整数ｎ＞１的最小素因子。
We introduce a minimal prime divisor,and show some properties of the maximal subgroup,and then apply them to discuss the classification of a group.
引进了最小素数因子p,揭示了极大子群的性质。
The calculation formula of pipeline thickness can be modified according to America practice,by importing the least thickness design factors,perfeeting the circumferential stress calculation formula,and determining the relationship between the pipelin.
可参照美国的做法,改进管道壁厚的计算公式,即引入最小壁厚设计因素,完善环向应力公式计算并研究确定管道壁厚与温差之间的关系。