Aspirin is synthesized through O - acylating reaction from acid and anhydride acid with anhydrous carbonate as catalyst.以水杨酸和乙酸酐为原料,采用无水碳酸钠作为催化剂经O - 酰化反应合成了阿司匹林.One advisable way is to synthesize NFM acylating morpholine...
我走出门，竖起衣领抵御冷雾。I stepped outside and pulled up my collar against the cold mist.人体的免疫系统是抵御疾病的主要屏障。The immune system is our main defence against disease.该防御工事能抵御当时所使用的各种进攻手段。The fortress was proof against the techniques of ...