群 PGL（2,7）与 PBIB 设计的构造

摘要

借助于射影一般线性群 PGL(2,7)在21个点上的本原作用,构造了两个部分平衡不完全区组设计。%By depending on the action of PGL(2,7)primitively on 21 points,two partially balanced incomplete block designs were constructed.