R ” 是取化基,如乙氧基 、 甲氧基及它们的环氧和烷氧同系物或卤基.R " is a replaceable function , e . g . acetoxy, methoxy, their acyloxy and alkoxy homologs or halo.蒸馏得质量分数高于98%的邻乙氧基苯甲酸,收率为92%.Distillation gave o ethoxybenzoic acid with 98 % of the p...
Chronic nonspecific ulcerative colitis is a disease with exacerbations and remissions.慢性非特异性溃疡性结肠炎这种病可以恶化亦可缓解.Ulcerative colitis and granulomatous colitis affect many children and young adults.溃疡性结肠炎和肉芽肿性结肠炎常侵害儿童和刚成年的年青人...