以氟化钾为催化剂, 催化十二烯基琥珀酸酐(DDSA)缩合成螺双内酯化合物.With potassium fluoride as catalyst, spironolactone compound was synthesized from DDSA.研究了双环戊二烯基铁作为燃料添加剂的应用.The application of ferrocene as fuel additive is studied.为此, 我们开展了对含环戊二烯基二硫...
She was silent, her eyes downcast.她一言不发,两眼低垂。Barbara looked increasingly downcast as defeat loomed.当败象已呈时,芭芭拉看上去越来越沮丧。Eyes downcast, she continued eating.她低垂双眼,不停地吃。...