中文摘要：

主要研究了一些对应于万有Teichmuller空间Pre-Schwarz导数模型中点的函数的拟共形扩张，得到了函数的拟共形扩张的复伸张与之Pre-Schwarz导数范数的一些关系，最后，通过具体构造一类函数的拟共形扩张表达式，得到了角域的Pre-Schwarz导数单叶性内径下界估计的另一种证明方法．

英文摘要：

This paper investigates some quasiconformal extensions of the functions corresponding to the points in the universal Teichmuller space by Pre-Schwarzian derivative, and finds some connections between the complex dilatations of the quasiconformal extension functions and the norms of the Pre-Schwarzian derivatives. In the last section of the paper, the authors find another proof for the lower bound of the inner radius of univalency for angular domains by constructing an explicit quasiconformal extension of a class of holomorphic functions.