简要介绍以此类方法对合成苯甲醛的研究.Based on the reactions , this paper reports research for synthesizing benzaldehyde.再溴代得到2-溴 -4,5-二甲氧基苯甲醛,收率为91.9%,并分析溴代过程中甲酰基的邻位效应及溴代产物的稳定性.This product with Br 2 was obtained 2 - bromo - 4,5 - hydroxy...
Objective : To evaluate the wind - damage effects on quality of heartwood of Lignum Santali Albi.目的: 评价风害损伤对檀香药材质量的影响.Heartwood from dark brown to purple brown, alternating stripes.心材暗红褐至紫褐色, 具深浅交替条纹.Sapwood contains xyl...
He turned away in sullen, resentful silence.他闷闷不乐、心怀怨恨、一言不发地转过身去了。The offenders lapsed into a sullen silence.那些冒犯者都闷不作声了。Bob looked pale and sullen.鲍勃脸色苍白,闷闷不乐。...