目的:研究有机溶剂及二氧化碳超临界萃取提取石香薷挥发油的提取条件,对比不同方法提取的挥发油成分上的差异。方法:有机溶剂和二氧化碳超临界萃取提取石香薷挥发油,成分分析采用GC-MS。结果:有机溶剂法提取石香薷挥发油的最佳提取条件...目的:研究有机溶剂及二氧化碳超临界萃取提取石香薷挥发油的提取条件,对比不同方法提取的挥发油成分上的差异。方法:有机溶剂和二氧化碳超临界萃取提取石香薷挥发油,成分分析采用GC-MS。结果:有机溶剂法提取石香薷挥发油的最佳提取条件为:提取总时间210 m in,溶剂与原料的投放总比例8∶1(m l∶g),提取温度65℃,提取率可达1.83%。超临界CO2法萃取石香薷挥发油,萃取率为3.4%。GC-MS分析鉴定结果表明:超临界CO2法萃取的石香薷挥发油主要成分为百里香酚,香荆芥酚,对聚伞花素,葎草烯等,其中百里香酚含量最高,占挥发油总量的56.25%,其次是香荆芥酚为19.21%;有机溶剂提取的挥发油中百里香酚和香荆芥酚的含量分别为58.33%和22.54%。结论:有机溶剂提取与超临界提取各具优点,有机溶剂法提取百里香酚和香荆芥酚含量高于超临界提取法,超临界法提取成分则多于有机溶剂提取法,本实验采用的超临界提取条件下有10种化合物首次在石香薷挥发油中发现。展开更多
对不同粒度的超细煤粉进行了粒度粉细和煤质分析测定,研究了超细煤粉的煤质分析特性随粒度的变化规律。对超细煤粉的工业分析表明,水分含量基本不随煤粉粒度的变化而变化;随着煤粉颗粒粒度的减小,灰分含量增大,挥发分含量减小。对超细...对不同粒度的超细煤粉进行了粒度粉细和煤质分析测定,研究了超细煤粉的煤质分析特性随粒度的变化规律。对超细煤粉的工业分析表明,水分含量基本不随煤粉粒度的变化而变化;随着煤粉颗粒粒度的减小,灰分含量增大,挥发分含量减小。对超细煤粉的元素分析表明,由于煤粉偏析,随着煤粉颗粒粒度的减小,C,H 和 N 含量降低,O 和 S 含量增大。展开更多
In this paper the Expendable Pattern Casting with dry sand Vacuum(EPC-V) process is used to manufacture iron matrix composites with tungsten carbide particle.Microstructures of the composites layers were analyzed.The ...In this paper the Expendable Pattern Casting with dry sand Vacuum(EPC-V) process is used to manufacture iron matrix composites with tungsten carbide particle.Microstructures of the composites layers were analyzed.The abrasive wear resistance of the composites layers were tested and compared with that of high chromium cast iron.The results show that the iron matrix composites with tungsten carbide particle have high hardness.The abrasive wear resistance of composites with tungsten carbide particle is higher than that of high chromium cast iron.The properties of the matrix materials have been improved remarkably.展开更多
文摘目的:研究有机溶剂及二氧化碳超临界萃取提取石香薷挥发油的提取条件,对比不同方法提取的挥发油成分上的差异。方法:有机溶剂和二氧化碳超临界萃取提取石香薷挥发油,成分分析采用GC-MS。结果:有机溶剂法提取石香薷挥发油的最佳提取条件为:提取总时间210 m in,溶剂与原料的投放总比例8∶1(m l∶g),提取温度65℃,提取率可达1.83%。超临界CO2法萃取石香薷挥发油,萃取率为3.4%。GC-MS分析鉴定结果表明:超临界CO2法萃取的石香薷挥发油主要成分为百里香酚,香荆芥酚,对聚伞花素,葎草烯等,其中百里香酚含量最高,占挥发油总量的56.25%,其次是香荆芥酚为19.21%;有机溶剂提取的挥发油中百里香酚和香荆芥酚的含量分别为58.33%和22.54%。结论:有机溶剂提取与超临界提取各具优点,有机溶剂法提取百里香酚和香荆芥酚含量高于超临界提取法,超临界法提取成分则多于有机溶剂提取法,本实验采用的超临界提取条件下有10种化合物首次在石香薷挥发油中发现。
文摘对不同粒度的超细煤粉进行了粒度粉细和煤质分析测定,研究了超细煤粉的煤质分析特性随粒度的变化规律。对超细煤粉的工业分析表明,水分含量基本不随煤粉粒度的变化而变化;随着煤粉颗粒粒度的减小,灰分含量增大,挥发分含量减小。对超细煤粉的元素分析表明,由于煤粉偏析,随着煤粉颗粒粒度的减小,C,H 和 N 含量降低,O 和 S 含量增大。
文摘In this paper the Expendable Pattern Casting with dry sand Vacuum(EPC-V) process is used to manufacture iron matrix composites with tungsten carbide particle.Microstructures of the composites layers were analyzed.The abrasive wear resistance of the composites layers were tested and compared with that of high chromium cast iron.The results show that the iron matrix composites with tungsten carbide particle have high hardness.The abrasive wear resistance of composites with tungsten carbide particle is higher than that of high chromium cast iron.The properties of the matrix materials have been improved remarkably.
