M -H2 O系中各溶液态物质在电势 pH平面内的优势区是Pourbaix图的一个重要内容。各物质的优势区大小由溶液态各物质的活性元素 (M)的总浓度T(M)决定 ;只有当各物质均含有相同数目的活性元素 (M)时 ,它们各自的优势区大小才与总浓度T(M)无关。T(M)一定时 ,E -pH平面内各点 (pH ,E)所对应的各物质的浓度可用改进的“二分法”求出。求出了Cu -H2 O系及不同总浓度T(S)和T(Cr)时简化的S -H2 O系和Cr-H2 O系各自的优势区域图。结果表明 ,随着T (S)的增加 ,S -H2 O系中较高级多硫化物的优势区增大 ,且移向低电势区 ;Cr -H2 O系中随T(Cr)的改变而变化最明显的是Cr3+,Cr(OH) 3,Cr(OH) -4 ,和Cr3(OH) 5+4的优势区。 The dominant region of each solution in the M -H 2 O system at the potential pH level is an important part of the Pourbaix plot. The size of the dominant region of each species is determined by the total concentration of active species (M) in the solution-state material. Only when all substances contain the same number of active elements (M), are their respective dominant size The total concentration T (M) has nothing to do. When T (M) is constant, the concentration of each substance corresponding to each point (pH, E) in the E-pH plane can be obtained by a modified “dichotomy”. The simplified regions of S-H 2 O and Cr-H 2 O were obtained for Cu-H 2 O and T (S) and T (Cr) The results show that with the increase of T (S), the dominant regions of the higher polysulfides in the S-H 2 O system increase and move toward the lower potential region. With the change of T (Cr) in the Cr-H 2 O system The most noticeable changes are the dominant regions of Cr3 +, Cr (OH) 3, Cr (OH) -4, and Cr3 (OH) 5 +4.