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. $是什么意思_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. $在线翻译_英语_读音_用法_例句