doubleraten.双率计doubleadj.双重的；成双的；两倍的v.翻一番；使 ... 加倍n.两倍；双份double walls structure双层墙double galvanized wire加厚锌层镀锌钢丝double-address sonar双址声呐double walled bell jar双层烧结钟罩double-emulsion film双层乳胶胶片Doubles-star Picture双星图double vanishing point双灭点double screen technique双屏技术double delta connection双三角接线double layer capacitors双电层电容器