[Objectives] To study the optimal extraction process for polysaccharides of Urtica fissa E. Pritz. [Methods] Leaves of wild U. fissa E. Pritz. collected in Nyingchi of Tibet were used as raw materials. Water extractio...[Objectives] To study the optimal extraction process for polysaccharides of Urtica fissa E. Pritz. [Methods] Leaves of wild U. fissa E. Pritz. collected in Nyingchi of Tibet were used as raw materials. Water extraction method was used to extract polysaccharides from U. fissa E. Pritz. Besides,comparison was made for the effects of extraction time,extraction temperature and solid-to-liquid ratio on the yield rate of polysaccharides from U. fissa E. Pritz. In addition,using the extraction time,extraction temperature and solid-to-liquid ratio as factors,L9( 33) orthogonal experiment was carried out to determine the optimal process parameters for water extraction of polysaccharides from U. fissa E. Pritz.[Results] The optimal process parameters: hot water extraction time was 4 h,the extraction temperature was 90℃,and the mass ratio of water to leaves of U. fissa E. Pritz. was 1∶ 25. Under such extraction conditions,the yield rate of polysaccharides from U. fissa E. Pritz.was up to 11. 611%. [Conclusions]This experiment is expected to provide certain reference for reasonable development and utilization of wild U. fissa E. Pritz. resources in Tibet.展开更多
The tunable propagation properties of 3D Dirac semimetal(DSM)-supported dielectric-loaded surface plasmons structures have been investigated in the THz regime,including the influences of the Fermi level of 3D DSM laye...The tunable propagation properties of 3D Dirac semimetal(DSM)-supported dielectric-loaded surface plasmons structures have been investigated in the THz regime,including the influences of the Fermi level of 3D DSM layer,the fiber shape and operation frequencies.The results indicate that the shape of dielectric fiber affects the hybrid mode significantly,on the condition that if ax(the semi-minor axis length of the dielectric semi-ellipse)is relatively small,the fiber shows good mode confinement and low loss simultaneously,and the figure of merit reaches more than 200.The propagation property can be manipulated in a wide range by changing the Fermi level of 3D DSM,e.g.if the Fermi level varies in the range of 0.05 eV–0.15 eV,the propagation length changes in the range of 9.073×10^(3)–2.715×10^(4)μm,and the corresponding modulation depth is 66.5%.These results are very helpful to understand the tunable mechanisms of the 3D DSM plasmonic devices,such as switchers,modulators,and sensors.展开更多
基金Supported by Project of Natural Science Foundation of Tibet Autonomous Region(2016ZR-15-31)
文摘[Objectives] To study the optimal extraction process for polysaccharides of Urtica fissa E. Pritz. [Methods] Leaves of wild U. fissa E. Pritz. collected in Nyingchi of Tibet were used as raw materials. Water extraction method was used to extract polysaccharides from U. fissa E. Pritz. Besides,comparison was made for the effects of extraction time,extraction temperature and solid-to-liquid ratio on the yield rate of polysaccharides from U. fissa E. Pritz. In addition,using the extraction time,extraction temperature and solid-to-liquid ratio as factors,L9( 33) orthogonal experiment was carried out to determine the optimal process parameters for water extraction of polysaccharides from U. fissa E. Pritz.[Results] The optimal process parameters: hot water extraction time was 4 h,the extraction temperature was 90℃,and the mass ratio of water to leaves of U. fissa E. Pritz. was 1∶ 25. Under such extraction conditions,the yield rate of polysaccharides from U. fissa E. Pritz.was up to 11. 611%. [Conclusions]This experiment is expected to provide certain reference for reasonable development and utilization of wild U. fissa E. Pritz. resources in Tibet.
基金the Natural Science Foundation of Shanghai under Grant Nos.21ZR1446500Shanghai Local College Capacity Building Project under Grant No.22010503300 and 21010503200+4 种基金the Research Funding of Shanghai Normal University under Grant No.SK202240National Natural Science Foundation of China under Grant Nos.61674106,12073018,U1931205the Funding of Shanghai Municipal Education Commission under Grant No 2019-01-07-00-02-E00032the Funding of Shanghai Municipality Science and Technology Commission under Grant No 19590746000,20070502400,YDZX20203100002498Student Research Project of Shanghai Normal University(undergraduate)under Grant No.22LKY022.
文摘The tunable propagation properties of 3D Dirac semimetal(DSM)-supported dielectric-loaded surface plasmons structures have been investigated in the THz regime,including the influences of the Fermi level of 3D DSM layer,the fiber shape and operation frequencies.The results indicate that the shape of dielectric fiber affects the hybrid mode significantly,on the condition that if ax(the semi-minor axis length of the dielectric semi-ellipse)is relatively small,the fiber shows good mode confinement and low loss simultaneously,and the figure of merit reaches more than 200.The propagation property can be manipulated in a wide range by changing the Fermi level of 3D DSM,e.g.if the Fermi level varies in the range of 0.05 eV–0.15 eV,the propagation length changes in the range of 9.073×10^(3)–2.715×10^(4)μm,and the corresponding modulation depth is 66.5%.These results are very helpful to understand the tunable mechanisms of the 3D DSM plasmonic devices,such as switchers,modulators,and sensors.
