A kinetic equation for ultrasonic-assisted extraction process was presented based on Fick’s first law of diffusion.The kinetics of ultrasonic-assisted extraction process agreed with the first-order rate equation.Expe...A kinetic equation for ultrasonic-assisted extraction process was presented based on Fick’s first law of diffusion.The kinetics of ultrasonic-assisted extraction process agreed with the first-order rate equation.Experiments for extracting chlorogenic acid from the leaves of Eucommia ulmoides were studied under different conditions to evaluate the kinetic equation.Experiment data could partly match the kinetic equation.It provided a theoretical reference for the ultrasonic-assisted extraction of Chinese traditional medicine.展开更多
Nano-sized Fe3O4 powder was prepared through an Oxygenation-Hydrothermal method. The chitosan magnetic complex was prepared by coating chitosan on the surface of Fe3O4 powders through Microlatex-Crosslinking Method. T...Nano-sized Fe3O4 powder was prepared through an Oxygenation-Hydrothermal method. The chitosan magnetic complex was prepared by coating chitosan on the surface of Fe3O4 powders through Microlatex-Crosslinking Method. The product was characterized by IR,XRD,TEM,Vibrating Sample Magnetometer (VSM),TG methods. Results show that the as-prepared powder is 25 nm in size and shows supermagnetism. The content of magnetite in microspheres is 37.8%. The mechanism for the coating reaction of chitosan to Fe3O4 nanoparticles is also suggested.展开更多
采用固定床反应装置,模拟汽车尾气的组成成分,以CO氧化和NH3选择还原NO为探针反应,研究了焙烧温度和焙烧时间等因素对复合金属氧化物催化材料Cu Mn Ce O γ Al2O3的催化活性的影响,并考察了该催化剂的抗硫化中毒性能。在本研究条件下,...采用固定床反应装置,模拟汽车尾气的组成成分,以CO氧化和NH3选择还原NO为探针反应,研究了焙烧温度和焙烧时间等因素对复合金属氧化物催化材料Cu Mn Ce O γ Al2O3的催化活性的影响,并考察了该催化剂的抗硫化中毒性能。在本研究条件下,焙烧温度在700℃左右,焙烧时间为2.5h时,催化剂对NO CO体系中CO的氧化率在76%以上,对NH3 NO体系中的NO的最佳催化还原率在80%以上。催化剂在3.0%SO2 空气气氛中强制中毒后,其在NH3 NO气氛中的最佳反应温度～450℃,同样条件下未中毒催化剂的最佳反应温度为350℃左右,并且催化剂中毒后对NO NH3的最大转化率没有下降,但是对NO CO体系的反应活性明显下降,说明该催化剂具有良好的高温活性和抗硫中毒性能。展开更多
文摘A kinetic equation for ultrasonic-assisted extraction process was presented based on Fick’s first law of diffusion.The kinetics of ultrasonic-assisted extraction process agreed with the first-order rate equation.Experiments for extracting chlorogenic acid from the leaves of Eucommia ulmoides were studied under different conditions to evaluate the kinetic equation.Experiment data could partly match the kinetic equation.It provided a theoretical reference for the ultrasonic-assisted extraction of Chinese traditional medicine.
文摘Nano-sized Fe3O4 powder was prepared through an Oxygenation-Hydrothermal method. The chitosan magnetic complex was prepared by coating chitosan on the surface of Fe3O4 powders through Microlatex-Crosslinking Method. The product was characterized by IR,XRD,TEM,Vibrating Sample Magnetometer (VSM),TG methods. Results show that the as-prepared powder is 25 nm in size and shows supermagnetism. The content of magnetite in microspheres is 37.8%. The mechanism for the coating reaction of chitosan to Fe3O4 nanoparticles is also suggested.
