IRBMn.中程弹道导弹IRabbr.信息检索(=information retrieval)irrigation before seeding播种前灌水,播前灌溉irrepressible laughter.抑制不住的大笑irreducible wave equation不可约波动方程irrgation sewage disposal污水灌溉处置irreducible system matrix不可约系统矩阵irrotational vector field无涡向量场,无旋矢量场,无旋向量场IR brightness temperature红外亮温irradiance heating system辐射供暖温度IR-IR optical resonance红外-红外双共振irrigation stage and rate灌水时期和灌水量