partially supported by NSFC (No.12071047);partially supported by NSFC (Nos.12071047,11701039);Fundamental Research Funds for the Central Universities (No.500421126)。
设h(x)是实轴上的保向同胚,满足h(±∞)=±∞.当h(x)的拟对称函数(,)()()()()x th x t h xρ=h x+?h?x?t(x∈R,t>0)被递减函数ρ(t)所控制时,h(x)的Beurling-Ahlfors扩张的伸缩商D(z)具有下述估计:21 1D≤ρ?+ρ??2,其中()2ρ?=ρy.