目的:探究金边龙舌兰总皂苷提取率的影响因素,优选总皂苷的提取工艺条件,研究总皂苷的体外抗氧化活性。方法:通过改变乙醇浓度、料液比、超声时间、超声温度等参数,结合正交试验,来优化金边龙舌兰总皂苷的提取过程;利用对DPPH自由基和羟基自由基的清除率进行金边龙舌兰总皂苷的体外抗氧化研究。结果:提取工艺最佳条件为乙醇浓度60%,料液比1:25,超声时间60 min,超声温度80℃,提取率为10.213%。结论:正交试验优选了金边龙舌兰中总皂苷的最优提取过程,体外抗氧化研究验证了金边龙舌兰总皂苷具有一定的抗氧化性能。本研究为金边龙舌兰的进一步开发利用提供了依据。Objective: To explore the factors affecting the extraction rate of total saponins from Agave americana var. Marginata, optimize the extraction conditions of total saponins from Agave americana var. Marginata, and study the antioxidant activity of total saponins from Agave americana var. Marginata in vitro. Methods: By changing parameters such as ethanol concentration, solid-liquid ratio, ultrasound time, ultrasound temperature, and combining orthogonal experiments, the extraction process of total saponins from Agave americana var. Marginata was optimized;In vitro antioxidant study of total saponins from Agave americana var. Marginata using their scavenging rates against DPPH and hydroxyl radicals. Results: The optimum extraction conditions were as follows: the concentration of ethanol was 60%, the ratio of solid to liquid was 1:25, the ultrasonic time was 60 min, and the ultrasonic temperature was 80˚C. The extraction rate was 10.213%. Conclusion: The optimum extraction process of total saponins from Agave americana var. Marginata was optimized by orthogonal test, and the in vitro antioxidant study verified that the total saponins from Agave americana var. Marginata had good in vitro antioxidant activity. This study provides a basis for the further development and utili
文章以硝酸锂和醋酸锰为原料,以水和丙烯酸为分散介质,采用溶胶—凝胶法在空气气氛下进行分段烧结,控制烧结温度和时间,成功制备了尖晶石结构Li Mn2O4粉体材料。通过XRD、SEM、恒电流充放电测试等手段研究了其形态、结构及电化学性能。结果表明:制备出来的粉体为尖晶石型锰酸锂,结晶度高,无杂质相。其中700℃烧结的样品晶粒大小约在58.9 nm,颗粒大小约为200 nm左右。在1 C的电流密度下,首次放电比容量为112 m Ah/g,经过30次循环放电比容量为104.3 m Ah/g,容量保持率在93.2%,充放电库仑效率接近100%。样品表现出良好的电化学性能。
