加醋于
- 与 加醋于 相关的网络例句 [注:此内容来源于网络,仅供参考]
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The ammonia was evaporated under decreasing pressure, and the precipitate was filtered off and the liquid was poured into hot saturated picric acid solution to get picrate with a yield of 85.0%. The optimum process starting from imidazole-4,5-dicarboxylic acid was: imidazole-4,5-dicarboxylic acid in acetic anhydride was refluxed to get imidazole-4-carboxylic acid, and the product was esterification in ethanol with a catalyzer of concentrated sulfuric acid to get ethyl imidazole-4-carboxylate, at last the compound above was reduced by LiAlH4 in ether at room temperature to get the target compound, the total yield of this route was 49.6%.
以4,5-二羧酸咪唑为原料的较佳工艺:1 脱羧反应:4,5-二羧酸咪唑40g,醋酐1200ml,回流10h,过滤并将滤液浓缩至干,所得固体加至50%的乙醇溶液回流,过滤并将滤液自然冷却过夜,过滤得固体;2 酯化反应:4(5)-羧酸咪唑50g,乙醇1000ml和浓硫酸60ml,加热回流2h,5%浓度NaOH溶液调节至pH=8,减压浓缩至干,加入少量水回流,自然冷却过夜并过滤得固体;3 还原反应:LiAlH410g,乙醚300ml和4(5)-羧酸咪唑乙酯28g,常温反应1.5h,小心滴加25ml水后过滤,滤渣溶于300ml甲醇中并过滤,收集所得乙醚和甲醇滤液浓缩至干,将所得固体溶于300ml乙醇中加热回流,后将溶液浓缩至约30ml,冷却并过滤得固体,该路线总收率为49.6%。
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Some of vinegar should be added when the bone that boil, make calcic dissolve is helpful for human body absorbing at Shang Zhong.
煮骨头时应加些醋,使钙溶于汤中有利于人体吸收。
- 推荐网络例句
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In the negative and interrogative forms, of course, this is identical to the non-emphatic forms.
。但是,在否定句或疑问句里,这种带有"do"的方法表达的效果却没有什么强调的意思。
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Go down on one's knees;kneel down
屈膝跪下。。。下跪祈祷
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Nusa lembongan : Bali's sister island, coral and sand beaches, crystal clear water, surfing.
Nusa Dua :豪华度假村,冲浪和潜水,沙滩,水晶般晶莹剔透的水,网络冲浪。