Asymmetric 1, 3 - dipolar cycloaddition can be strongly catalyzed by chiral oxazaborolidines.手性唑硼烷酮能够催化不对称1, 3偶极加成反应并取得很好的效果.Most people's faces are asymmetric.大多数人的脸不对称。There are two DesB 1 - DPI moleCUles in an as...
Air raid wardens in tin hats self - importantly stalked the streets.空袭民防队员戴着钢盔神气活现地走在街上昂首阔步....wide-brimmed hats with red pom-poms worn by the local girls.当地女孩戴的宽边、有红色绒球的帽子The salesman showed her nearly all the hats in t...
Bereavements and blessings, one following anther , make us and blessed by turns.丧亲之痛和神恩赐福此起彼伏, 让我们悲欢交替.Afflictions are sometimes blessings in disguise.塞翁失马,焉知非福.God's blessings are chasing me down and overtaking me....
a crown studded with gems镶有宝石的皇冠The apt citations and poetic gems have adorned his speeches.贴切的引语和珠玑般的诗句为他的演说词增添文采.The Dunhuang frescoes are gems of ancient Chinese art.敦煌壁画是我国古代艺术中的瑰宝....
a heartbreaking story伤心的故事This year we won't even be able to buy presents for our grandchildren. It's heartbreaking.今年我们甚至无法给自己的孙儿辈买礼物了。这真让人心碎。After this heartbreaking experience, Thorpe turned to professional ...