positive arc正弧positiveadj.积极的；肯定的；明确的；正面的；正数的；阳性的n.正面；正数；正片；[语]原级positive steady-state正平衡点positive self-concept积极自我概念positive symmetry model正向对称模型positive double complex正二重复形positive phase sequence顺相序positive dihedral angle正反角positive supply voltage正相电源电压positive mistranslation积极性误译Positive selected sites正向选择位点positive sealing system可靠止水系统