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 poll response肯定查询响应positive magnetic bays正湾扰positive cooperativity正协同(性), 正协同反应positive axis P-axis压力轴positive daigeotropism下横向生地positive feedback path正反馈路径positive pressure wave正压力波,正向压力波positive-ray current阳射线电流positive bilinear form正双线性形式positive mark polarity正的传号极性