Dual law二元法dualadj.双重的；成双的n.双数Dual-wavelength operation双波长运转dual qualitative similarity双定性相似度dual single planetary gears单排双星dual-frequency IP methods双频激电Dual response surface model双响应面模型dual-headed configuration双头配置dual pressure steam turbine双压式汽轮机dual-polarized ring laser双偏振环形激光器dual-time stepping method双时间推进算法dual-axis universal joint双轴万向接头