Vanadium redox flow batteries(VRFBs)are one of the most promising energy storage systems owing to their safety,efficiency,flexibility and scalability.However,the commercial viability of VRFBs is still hindered by the ...Vanadium redox flow batteries(VRFBs)are one of the most promising energy storage systems owing to their safety,efficiency,flexibility and scalability.However,the commercial viability of VRFBs is still hindered by the low electrochemical performance of the available carbon-based electrodes.Defect engineering is a powerful strategy to enhance the redox catalytic activity of carbon-based electrodes for VRFBs.In this paper,uniform carbon defects are introduced on the surfaces of carbon felt(CF)electrode by Ar plasma etching.Together with a higher specific surface area,the Ar plasma treated CF offers additional catalytic sites,allowing faster and more reversible oxidation/reduction reactions of vanadium ions.As a result,the VRFB using plasma treated electrode shows a power density of 1018.3 mW/cm^(2),an energy efficiency(EE)of 84.5%,and the EE remains stable over 1000 cycles.展开更多
Lonicerae flos,a widely used traditional Chinese medicine(TCM),has been used for several thousand years in China.As a famous traditional Chinese herbal medicine,it was used as heat-clearing drug and alexipharmic agent...Lonicerae flos,a widely used traditional Chinese medicine(TCM),has been used for several thousand years in China.As a famous traditional Chinese herbal medicine,it was used as heat-clearing drug and alexipharmic agent and was widely cultivated in Hunan province.L.flos mainly contains biologically active compounds such as caffeic acid derivatives,essential oil,flavonoids,iridoid glycosides and terpenoids.A range of biological activities has been reported from plant extracts including anti-inflammatory,antitumor,antioxidant,antiallergy,immunomodulating and antibacterial activity.In this study,the author investigated ancient books of TCM and nowadays reports,summarized the chemical constituents,biological activity of L.flos to provide a comprehensive systematic review.展开更多
An optimization method for sound absorption of gradient(multi-layered) sintered metal fiber felts is presented. The theoretical model based on dynamic flow resistivity is selected to calculate the sound absorption coe...An optimization method for sound absorption of gradient(multi-layered) sintered metal fiber felts is presented. The theoretical model based on dynamic flow resistivity is selected to calculate the sound absorption coefficient of the sintered metal fiber felts since it only requires three key morphological parameters: fiber diameter, porosity and layer thickness. The model predictions agree well with experimental measurements. Objective functions and constraint conditions are then set up to optimize separately the distribution of porosity, fiber diameter, and simultaneous porosity and fiber diameter in the metal fiber. The optimization problem for either a sole frequency or a pre-specified frequency range is solved using a genetic algorithm method. Acoustic performance comparison between optimized and non-optimized metal fibers is presented to confirm the effectiveness of the optimization method. Gradient sintered metal fiber felts hold great potential for noise control applications particularly when stringent restriction is placed on the total volume and/or weight of sound absorbing material allowed to use.展开更多
基金Project(Xiang Zu [2016] 91) supported by the “100 Talented Teams” of Hunan Province,ChinaProject(2018RS3077) supported by the Huxiang High-level Talents Program,China+2 种基金Project(22002009) supported by the National Natural Science Foundation of ChinaProject(2021JJ40565) supported by the Natural Science Foundation of Hunan Province,ChinaProject(19C0054) supported by the Scientific Research Foundation of Hunan Provincial Education Department,China。
文摘Vanadium redox flow batteries(VRFBs)are one of the most promising energy storage systems owing to their safety,efficiency,flexibility and scalability.However,the commercial viability of VRFBs is still hindered by the low electrochemical performance of the available carbon-based electrodes.Defect engineering is a powerful strategy to enhance the redox catalytic activity of carbon-based electrodes for VRFBs.In this paper,uniform carbon defects are introduced on the surfaces of carbon felt(CF)electrode by Ar plasma etching.Together with a higher specific surface area,the Ar plasma treated CF offers additional catalytic sites,allowing faster and more reversible oxidation/reduction reactions of vanadium ions.As a result,the VRFB using plasma treated electrode shows a power density of 1018.3 mW/cm^(2),an energy efficiency(EE)of 84.5%,and the EE remains stable over 1000 cycles.
基金funding support from the Key Laboratory For Quality Evaluation of Bulk Herbs of Hunan Province and national science foundation of China (No.81374062 and No.81673579)
文摘Lonicerae flos,a widely used traditional Chinese medicine(TCM),has been used for several thousand years in China.As a famous traditional Chinese herbal medicine,it was used as heat-clearing drug and alexipharmic agent and was widely cultivated in Hunan province.L.flos mainly contains biologically active compounds such as caffeic acid derivatives,essential oil,flavonoids,iridoid glycosides and terpenoids.A range of biological activities has been reported from plant extracts including anti-inflammatory,antitumor,antioxidant,antiallergy,immunomodulating and antibacterial activity.In this study,the author investigated ancient books of TCM and nowadays reports,summarized the chemical constituents,biological activity of L.flos to provide a comprehensive systematic review.
基金supported by the National Natural Science Foundation of China(Grant No.51528501)the Fundamental Research Funds for Central Universities(Grant No.2014qngz12)Xin is supported by China Scholarship Council as a visiting scholar to Harvard University
文摘An optimization method for sound absorption of gradient(multi-layered) sintered metal fiber felts is presented. The theoretical model based on dynamic flow resistivity is selected to calculate the sound absorption coefficient of the sintered metal fiber felts since it only requires three key morphological parameters: fiber diameter, porosity and layer thickness. The model predictions agree well with experimental measurements. Objective functions and constraint conditions are then set up to optimize separately the distribution of porosity, fiber diameter, and simultaneous porosity and fiber diameter in the metal fiber. The optimization problem for either a sole frequency or a pre-specified frequency range is solved using a genetic algorithm method. Acoustic performance comparison between optimized and non-optimized metal fibers is presented to confirm the effectiveness of the optimization method. Gradient sintered metal fiber felts hold great potential for noise control applications particularly when stringent restriction is placed on the total volume and/or weight of sound absorbing material allowed to use.
