Dried leaves of <i><span style="font-family:Verdana;">Eucalyptus</span></i> <i><span style="font-family:Verdana;">camaldulensis</span></i><span st...Dried leaves of <i><span style="font-family:Verdana;">Eucalyptus</span></i> <i><span style="font-family:Verdana;">camaldulensis</span></i><span style="font-family:Verdana;"> were finely grinded and fractionated</span><span style="font-family:;" "=""><span style="font-family:Verdana;"> by sieving into four granulometric classes (<100 μm, 100 - 200 μm, 200 - 355 μm and >355 μm). The obtained powder fractions were used for essential oil (EO) extraction by hydrodistillation and their phytochemical profile and </span><i><span style="font-family:Verdana;">in</span></i> <i><span style="font-family:Verdana;">vitro</span></i><span style="font-family:Verdana;"> antioxidant activities were evaluated. The mother powder (unsieved powder) was used for comparison. Particle size exerted a significant influence (</span><i><span style="font-family:Verdana;">p</span></i><span style="font-family:Verdana;"> < 0.05) on the phytochemical composition and </span><i><span style="font-family:Verdana;">in</span></i> <i><span style="font-family:Verdana;">vitro</span></i><span style="font-family:Verdana;"> antioxidant prop</span><span><span style="font-family:Verdana;">erties of the EOs. Comparatively, the mother powder had the highest contents of </span><i><span style="font-family:Verdana;">α</span></i><span style="font-family:Verdana;">-pinene (55.6%), camphene (3.4%) and limonene (3.7%), while 1,8-cineole (26.6% and 22.4%), </span></span><span style="font-family:Verdana;">exo-fenchol (5.6% and 3.5%), </span><i><span style="font-family:Verdana;">α</span></i><span style="font-family:Verdana;">-campholenol (4.2% and 3.4%), L-trans-pinocarveol (5.5% and 2.7%), L-borneol (12.6% and 6.8%) and </span><i><span style="font-family:Verdana;">α</span></i><span style="font-family:Verdana;">-terpineol (16.4% and 7.6%) are the main compounds of EOs from the <100 μm and 100 - 200 μm fractions, respectively. The antioxidant activities of the EOs revealed higher radical-scavenging activities DPPH (90.62% and 70.46%) and ABTS (89.59% and 73.31%) for finer fractions (<100 μm and 100 - 200 μm, respectively). The best reducing power (36.15% and 34.27%) were also found in these finer powder fractions which improved by more than 2 times the value of mother powder (reducing power of 17.01%). These results suggest that grinding followed by sieve fractionation concentrates the majority of antioxidant phytochemicals in the EOs of the finer powder fractions of </span><i><span style="font-family:Verdana;">E.</span></i> <i><span style="font-family:Verdana;">camaldulensis</span></i><span style="font-family:Verdana;"> leaves. Finer powders could be used as functional ingredients in food formulations for the management of chronic diseases.</span></span>展开更多
管道内粉体的气力输运广泛存在于化工、食品加工、电力、冶金和医药等工业生产过程中.通过对粉体颗粒的速度、体积分数和粒度等关键参数进行在线测量,可实现过程优化控制,提高生产效率和产品质量,降低能耗.本文从声散射理论模型出发,数...管道内粉体的气力输运广泛存在于化工、食品加工、电力、冶金和医药等工业生产过程中.通过对粉体颗粒的速度、体积分数和粒度等关键参数进行在线测量,可实现过程优化控制,提高生产效率和产品质量,降低能耗.本文从声散射理论模型出发,数值模拟并拟合出超声衰减系数和声速随粉体体积分数的变化关系.设计中心频率为30 k Hz的一体式超声波探针,在杭州某水泥厂输运管道进行管内不同深度测点水泥生料粉体浓度的在线测量,分别以衰减和声速方法获得管内粉体沿径向的体积分数分布.展开更多
文摘Dried leaves of <i><span style="font-family:Verdana;">Eucalyptus</span></i> <i><span style="font-family:Verdana;">camaldulensis</span></i><span style="font-family:Verdana;"> were finely grinded and fractionated</span><span style="font-family:;" "=""><span style="font-family:Verdana;"> by sieving into four granulometric classes (<100 μm, 100 - 200 μm, 200 - 355 μm and >355 μm). The obtained powder fractions were used for essential oil (EO) extraction by hydrodistillation and their phytochemical profile and </span><i><span style="font-family:Verdana;">in</span></i> <i><span style="font-family:Verdana;">vitro</span></i><span style="font-family:Verdana;"> antioxidant activities were evaluated. The mother powder (unsieved powder) was used for comparison. Particle size exerted a significant influence (</span><i><span style="font-family:Verdana;">p</span></i><span style="font-family:Verdana;"> < 0.05) on the phytochemical composition and </span><i><span style="font-family:Verdana;">in</span></i> <i><span style="font-family:Verdana;">vitro</span></i><span style="font-family:Verdana;"> antioxidant prop</span><span><span style="font-family:Verdana;">erties of the EOs. Comparatively, the mother powder had the highest contents of </span><i><span style="font-family:Verdana;">α</span></i><span style="font-family:Verdana;">-pinene (55.6%), camphene (3.4%) and limonene (3.7%), while 1,8-cineole (26.6% and 22.4%), </span></span><span style="font-family:Verdana;">exo-fenchol (5.6% and 3.5%), </span><i><span style="font-family:Verdana;">α</span></i><span style="font-family:Verdana;">-campholenol (4.2% and 3.4%), L-trans-pinocarveol (5.5% and 2.7%), L-borneol (12.6% and 6.8%) and </span><i><span style="font-family:Verdana;">α</span></i><span style="font-family:Verdana;">-terpineol (16.4% and 7.6%) are the main compounds of EOs from the <100 μm and 100 - 200 μm fractions, respectively. The antioxidant activities of the EOs revealed higher radical-scavenging activities DPPH (90.62% and 70.46%) and ABTS (89.59% and 73.31%) for finer fractions (<100 μm and 100 - 200 μm, respectively). The best reducing power (36.15% and 34.27%) were also found in these finer powder fractions which improved by more than 2 times the value of mother powder (reducing power of 17.01%). These results suggest that grinding followed by sieve fractionation concentrates the majority of antioxidant phytochemicals in the EOs of the finer powder fractions of </span><i><span style="font-family:Verdana;">E.</span></i> <i><span style="font-family:Verdana;">camaldulensis</span></i><span style="font-family:Verdana;"> leaves. Finer powders could be used as functional ingredients in food formulations for the management of chronic diseases.</span></span>
文摘管道内粉体的气力输运广泛存在于化工、食品加工、电力、冶金和医药等工业生产过程中.通过对粉体颗粒的速度、体积分数和粒度等关键参数进行在线测量,可实现过程优化控制,提高生产效率和产品质量,降低能耗.本文从声散射理论模型出发,数值模拟并拟合出超声衰减系数和声速随粉体体积分数的变化关系.设计中心频率为30 k Hz的一体式超声波探针,在杭州某水泥厂输运管道进行管内不同深度测点水泥生料粉体浓度的在线测量,分别以衰减和声速方法获得管内粉体沿径向的体积分数分布.
