dualbeamadj.双射线的n.双电子束dualadj.双重的；成双的n.双数dual-pick-up synchro control双光头同步控制dual system vocational education双元制职业教育dual level fertilizer applicator双层施肥机Dual Waveband Imaging Radiometer双波带图像辐射计dual-rate moon position camera双速率月球位置摄影机dual metric locally convex space对偶度量局部凸空间dual-pattern light measurement双区测光dual polarization spectrum reuse双极化频谱复用dual-certification integration双证融通dual-layer granular bed filter双层滤料颗粒床