positive ray正电射线,阳射线,正电荷离子射线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 displacement bladder挤压囊positive displacement stuffer定容填充机positive correlative property正相关性positive and negative priming正负启动positive-sequence component正序分量positively oriented trihedral正指向的三面形的positive staircase phenomenon正阶梯现象positive nitrogen equilibrium正氮平衡positive pressure urethrogram正压尿道造影(照)片positive and negative meaning褒贬