By virtue of the extension technique of functions and the duality properties of Hardy space and BMO space,a simple proof of the boundary regularity for this class of weakly harmonic maps is shown. $

• 利用函数的延拓技巧以及 Hardy空间和 BMO空间的对偶性 ,对这类弱调和映射的边界正则性给出一个简明的证明