中文摘要：

研究从单连通区域Ω包含R^2∪{∞}到酉群U（N）的实形式G（包括正交群和辛群）的调和映射，给出了增加G-uniton数的两种充要条件．证明任何G-n-uniton可以从一个0-uniton通过纯代数运算和求解δ^-问题的积分变换构造而得，并给出了可增加G-uniton数的G-旗因子的两种纯代数构造方法．

英文摘要：

The harmonic maps from a simply connected domain Ω lohtain in R^2∪{∞} into some real forms of unitary group U（N）, which contain symplectie groups and orthogonal groups, are studied. Two kinds of criterions of adding G-uniton numbers are proposed. It is proved that any G-n-uniton can be obtained from a 0-uniton by purely algebraic operations and integral transformations to solve the δ^- - problem. Two kinds of purely algebraic ways to construct G-flag factors by adding uniton numbers are also proposed.