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Hydroxyquinol triacetate was prepared from p-benzoquinone by 1,4-addition reaction with acetic anhydride and then 6,7-dihydroxy coumarin was synthesized from it by hydrolyze and cyclization in concentrated sulfuric acid.Then 6,7-dimethoxy coumarin was syn |
中文意思: 对苯醌与乙酸酐经1,4-加成生成1,2,4-苯三酚三乙酸酯,然后与苹果酸反应经水解、环合反应得6,7-二羟基香豆素,再经甲基化得到6,7-二甲氧基香豆素,总收率为74.4%,整个过程反应条件温和,操作方便,适合工业生产的要求,对产品结构进行了IR和1HNMR表征。 |
以下为相关句子列表(点击查看,可以看对应的解释):
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Hydrostatic transmission, double drive, two amplitudes, 3 speed range, infinitely variable speed, good over-lap-ping.
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全液压、双驱动、双振幅、三档无级变速,十字铰接式车架。 |
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Hydrostatic transmission,double drive,two amplitudes,two gears and infinitely variable speed.
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全液压、双驱动、双振幅、两档无极变速。 |
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Hydrotherapy is especially effective to cancer under or on the skin. It is also very effective to all kinds of bruises, sprains, muscles pain, ligament, joint problems and injures, etc.
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这方法特别对较近皮肤的癌症帮助较大,如皮肤癌、骨癌、喉癌等,亦对撞伤、扭伤、肌肉、韧带、关节等痛症和损伤十分之好。而全身冷热水浴对全身都有好处,有助增强抵抗力。 |
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Hydrous magnesium oxysulfate whisker is a new type of fibroid material used as flame retardants and reiforcers.
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摘要硷式硫酸镁晶须是新型的阻燃、增强纤维材料,有著广阔的应用前景。 |
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Hydroxynitrile lyases are the versatile group of enzymes, which play a significant defensive role in plant system against microbial attack.
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摘要醇腈酶是用途较广的一类酶,在植物体内抵御微生物侵袭方面起着重要作用。 |
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Hydroxyquinol triacetate was prepared from p-benzoquinone by 1,4-addition reaction with acetic anhydride and then 6,7-dihydroxy coumarin was synthesized from it by hydrolyze and cyclization in concentrated sulfuric acid.Then 6,7-dimethoxy coumarin was syn
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对苯醌与乙酸酐经1,4-加成生成1,2,4-苯三酚三乙酸酯,然后与苹果酸反应经水解、环合反应得6,7-二羟基香豆素,再经甲基化得到6,7-二甲氧基香豆素,总收率为74.4%,整个过程反应条件温和,操作方便,适合工业生产的要求,对产品结构进行了IR和1HNMR表征。 |
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Hygienic standard for arsenic and its inorganic compounds in the air of workplace.
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车间空气中砷及其无机化合物卫生标准. |
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Hygienic standard for environmental meteorology in underground workplace of coal mine.
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煤矿井下采掘作业地点气象条件卫生标准. |
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Hygroscopic Able to absorb water from the surroundings, including moisture from the atmosphere.
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吸湿的:指可以从周围环境中吸收水分,包括大气中的湿气。 |
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Hymall's superstores are mainly in the east, north and north-east of China and serve about 2m customers a week.
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乐购的超市主要位于中国华东、华北和东北地区,每周接待大约200万名顾客。 |
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Hyman, S. Mental Illness: Genetically Complex Disorders of Neural Circuitry and Neural Communication.Neuron 28 (2000): 321-323.
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《神经细胞》28(2000):321-323,〈精神疾病:由基因所引起的神经回路和神经通讯障碍. |
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