Cyclobutane exists predominantly in a " butterfly " conformation.环丁烷主要成 “ 蝶式 ” 构象存在.On the other hand , cyclobutane pyrimidine dimmer ( CPD ) just has an effect of cell cycle arrest.而CPD光 产物 ( cyclobutanepyrimidinedimmer...
There were also several accidents mainly caused by engine failures on take-off.还有几次事故主要是起飞时引擎出现故障造成的。Many motor accidents are the result of unthinkingly mixing speed and alcohol.许多机动车事故都是不计后果地酒后开快车造成的。With a little foret...