Polyurethane elastomers based on glycols ( PEA, PPG PTMG ) , diisocyanate ( TDI ) and chain extender ( E - 300 ) were prepared.以多元醇 ( PEA, PPG,PTMG ),PDI, E300为原料,制备了 PU 弹性体.Polyether - type isocyanate prepolymers are pr...
Hexamethylene diisocyanate ( HMDI ) may be used in prepolymer, in place of TDI.六亚甲基二异氰酸酯 ( HMDI ) 可用在预聚物中代替甲苯二异氰酸酯〔TDI〕.Polyurethane elastomers based on glycols ( PEA, PPG PTMG ) , diisocyanate ( TDI ) and chain extender...
她向下走到一半时，听到了响声。She was halfway down when she heard the noise.戴维小心翼翼地往前挪，从边缘向下张望。David moved cautiously forward and looked over the edge.她弯腰向下,左右手交叉触及脚趾.She reached down, touching her toes with opposite hands....
装在窗框上的厚厚的胶合板挡住了白天的光线。Thick chipboard across the window frames blocked out the daylight.我并不介意白天的噪音。I don't mind the noise during the day.预订了今天白天的戏票.I have ticket reserved for today's matinee....
东海岸的土地贫脊.The land is barren on the east coast.苏格兰西海岸的这一段完全暴露在大西洋海风前。This part of the west coast of Scotland is very exposed to Atlantic winds.想象一下你正躺在海滩上，倾听海浪有节奏地轻轻拍打海岸的声音。Imagine you're lying on a beach, listening ...