在 [Lei, Zhen; Zhang, Qi. Criticality of the axially symmetric Navier-Stokes equations. Pacific J. Math. 289 (2017), no. 1, 169--187] 中, 作者证明了如果 $$ex sup_{tgeq 0} |ru^ t(t,r,z)|leq C_*|ln r|^{-2},quad rleq del_0insex{0,f{1}{2}},quad C_*<infty, eex$$ 则解光滑.