未知元 meaning in English

unknown

A mixed semi - implicit scheme based on incremental unknowns
基于增量未知元的混合半隐格式
On stability and error estimaes for a class of weighted semi - implicit schemes of the incremental unknowns methods
一类加权半隐格式增量未知元方法的稳定性和误差估计
A priori estimates of incremental unknowns methods on a class of special nonuniform meshes for three dimensional problems
一类特殊非一致网格上三维问题增量未知元方法的先验估计