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《化学试剂》2021,43(7):986-991
为确定从蝙蝠葛根中提取生物碱的最佳工艺,以蝙蝠葛根为材料、乙醇溶液为提取剂,利用超声波辅助提取蝙蝠葛根生物碱。在超声功率175 W的条件下,通过单因素试验考察乙醇浓度、超声温度、超声时间、料液比对超声提取蝙蝠葛生物碱提取量的影响。应用Box-Benhnken中心组合方法进行4因素3水平设计,以蝙蝠葛根生物碱提取量为响应值,采用响应面法优化蝙蝠葛根生物碱的提取工艺。结果表明,超声波辅助提取蝙蝠葛根中生物碱的最佳工艺为料液比1∶40(g/mL)、乙醇浓度70%、超声温度40℃、超声时间2 h,在此工艺条件下,蝙蝠葛根生物碱的提取量为9.067 mg/g。该工艺条件切实可行,可用于控制和预测蝙蝠葛根中生物碱的提取。 相似文献
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超声波提取黄芩药渣中的黄芩苷 总被引:1,自引:0,他引:1
为了探索黄芩植物药废渣的再利用价值,首次采用超声波萃取技术对黄芩植物药废渣中的药用有效成分-黄芩苷进行再次提取,考察溶剂浓度、超声提取时间以及溶剂量等因素对黄芩苷提取率的影响。设计正交实验对超声波提取工艺参数进行优化。结果表明超声波最佳提取工艺条件为:15倍量70%浓度的乙醇,在20℃条件下超声提取50min,黄芩苷提取率达6.0%以上。通过试验得出的结论为:黄芩植物药废渣中尚含有一定量的药用有效成分-黄芩苷,具有再资源化利用的价值。 相似文献
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The transport properties of ionic liquids (ILs) are crucial properties in view of their applications in electrochem-ical devices. One of the most important advantages of ILs is that their chemical–physical properties and conse-quently their bulk performances can be well tuned by optimizing the chemical structures of their ions. This will require elucidating the structural features of the ions that fundamentally determine the characteristics of the nanostructures and the viscosities of ILs. Here we showed for the first time that the“rigidity”, the order, and the compactness of the three-dimensional ionic networks generated by the anions and the cation head groups determine the formation and the sizes of the nanostructures in the apolar domains of ILs. We also found that the properties of ionic networks are governed by the conformational flexibility and the symmetry of the anion and/or the cation head group. The thermal stability of the nanostructures of ILs was shown to be con-trolled by the sensitivity of the conformational equilibrium of the anion to the change of temperature. We showed that the viscosity of ILs is strongly related to the symmetry and the flexibility of the constitute ions rather than to the size of the nanostructures of ILs. Therefore, the characteristics of the nanostructures and the viscosities of ILs, especially the thermal stability of the nanostructures, can be fine-tuned by tailoring the symmetry and the conformational flexibility of the anion. 相似文献
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催化装置粗汽油回炼技术在有效降低催化稳定汽油烯烃含量的同时,对催化装置产品分布产生明显的影响,继而影响到装置的综合经济效益。本文对不同粗汽油回炼量条件下,催化装置稳定汽油性质和产品分布变化趋势进行分析,对经济效益进行对比,阐明应用粗汽油回炼降低汽油烯烃技术时,要选择合适的操作条件,以期得到较好的综合经济效益。 相似文献
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磷尾矿中元素赋存状态研究方法的探讨 总被引:3,自引:0,他引:3
对磷尾矿中元素赋存状态的一些研究方法进行了讨论,通过讨论对磷尾矿的综合研究、合理开发利用、重新设计选冶工艺流程等领域都具有十分重要的意义。 相似文献