The progresses in five - membered heterocyclic metallocene analogic complexes and their application in olefin polymerization are reviewed. 综述了五元杂环类茂金属配合物的研究进展及其在烯烃聚合中的应用.
利昂娜将一些清洁剂放入洗碗机，关上门后按了开始键。Leona put some detergent into the dishwasher, shut the door and pressed the switch.利昂娜: 怎么会是? 他们逃跑了马?Leona : what happened ? Did they get away?乔: 妮有什么主意吗, 利昂娜?Joe: have you got any ideas, Leona?...
Through nitrosation , hydrogenate reducion, and acylate three steps, the yield surpass 80 % for the diethyl malonate.收率相对于丙二酸二乙酯达到了80%以上.The necessary material of 2 - ( 2 - methoethyl ) acetaldehyde diethyl acetal was sy...
"I'm afraid he's ill." — "I'm sorry to hear that."“恐怕他生病了。”——“真是遗憾。”She could hear his ragged breathing, as if he had been running.她能听到他不均匀的呼吸声，似乎他是跑着过来的。"I think I hear the telephone ringing."—"Okay, I ca...
I answered yes in a quavering voice.我用颤抖的声音说是.Even his voice became quavering and lost its old masterfulness.他说话的声音已不象当年那样斩钉截铁,铿锵有力,而是含含混混、结结巴巴、有气无力.The gentle breeze set the flames of the lamps quavering.微风吹得灯火微微跳动....
槭糖浆是用糖槭树中提取的树液制成的。Maple syrup is made from sap extracted from the sugar maple tree.我们用的盐有些是从海水中提取的.Some of the salt that we use is obtained from the sea.从这种根部提取的护肤液是治疗皮疹和丘疹的极好药物。A skin lotion distilled from the root is a...