单面涂层双层纸板
one-side coated duplex board
迭层式双折射膜系
complex multilayer birefringent film
滚筒式双层筛砂机
cylinder double layer sand siftering machine
立式双层鼓轮
vertical double draft bull block
生铀层双层结构
Uranium-bearing double—layer structure
双层式结构
two-layer stratigraphic structure
双层双跨混凝土框架
double-story and double-span RC frame
双层双曲抛物面网格壳
hyperbolic parabolic double-deck reticulated shall
双层双扇形
double-layer twin fans shaping