The effect of commercial frequency electromagnetic field on the solidification structure and mechanical propertiesof copper hollow blanks prepared by horizontal continuous casting method was investigated. The results ...The effect of commercial frequency electromagnetic field on the solidification structure and mechanical propertiesof copper hollow blanks prepared by horizontal continuous casting method was investigated. The results show thatwhen the electromagnetic field is imposed, columnar grains are evidently refined and fine equiaxed grains areobtained in the inner side of the cross-section. Moreover, with the increase of input current, the equiaxed grain regionwidens and the grains distribute more uniformly in the circumferential direction. Meanwhile, the mechanical properties areremarkably improved by the application of electromagnetic field. When the input current is 140 A, the tensile strengthincreases 15% and the elongation increases 10%. However, the electromagnetic field has no effect on the distribution ofmicroelements.展开更多
Urban black blooms that are primarily caused by organic carbon are deleterious environmental problems.However,detailed studies on the microbial characteristics that form urban black blooms are lacking.In this study,we...Urban black blooms that are primarily caused by organic carbon are deleterious environmental problems.However,detailed studies on the microbial characteristics that form urban black blooms are lacking.In this study,we observed the composition,diversity,and function of bacterial community in the overlying water and sediments during the occurrence and remediation of urban black blooms using high-throughput 16S rRNA gene amplicon sequencing analysis.First,we found that pivotal consortia in the overlying water increased significantly during the formation of black blooms,including the genera Acidovorax,Brevundimonas,Pusillimonas,and Burkholderiales involved in the degradation of refractory organics,as well as the genera Desulfovibrio,Dechloromonas,and Rhizobium related to the production of black and odorous substances.An RDA analysis revealed that chemical oxygen demand,dissolved oxygen,and oxidation reduction potential were related to the changes in microbial community composition.Furthermore,aeration was found to accelerate the removal of ammonia nitrogen and enhance the function of microbial community by stimulating the growth of order Planktomycetes during the remediation of black blooms,but aeration substantially damaged the microbial diversity and richness.Therefore,the health of the aquatic ecosystem should be comprehensively considered when aeration is applied to restore polluted waterbodies.Notably,we observed a large number of pathogenic bacteria in urban black blooms,which emphasizes the importance of treating domestic sewage so that it is harmless.Together,these findings provide new insights and a basis to prevent and manage urban black blooms.展开更多
Electrocatalytic water splitting offers a sustainable route for hydrogen production,enabling the clean and renewable alternative energy system of hydrogen economy.The scarcity and high-cost of platinum-group-metal(PGM...Electrocatalytic water splitting offers a sustainable route for hydrogen production,enabling the clean and renewable alternative energy system of hydrogen economy.The scarcity and high-cost of platinum-group-metal(PGM)materials urge the exploration of high-performance non-PGM electrocatalysts.Herein,a unique hierarchical structure of NiA/2O3 with extraordinary electrocatalytic performance(e.g.t overpotentials as low as 22 mV at 20 mA·cm^-2 and 94 mV at 100 mA·cm^-2)toward hydrogen evolution reaction in alkaline electrolyte(1 M KOH)is reported.The investigation on the hierarchical NiA/2O3 with a bimodal size-distribution also offers insight of interfacial engineering that only proper NiA/2O3 interface can effectively improve H20 adsorption,H20 dissociation as well as H adsorption,for an efficient hydrogen production.展开更多
文摘The effect of commercial frequency electromagnetic field on the solidification structure and mechanical propertiesof copper hollow blanks prepared by horizontal continuous casting method was investigated. The results show thatwhen the electromagnetic field is imposed, columnar grains are evidently refined and fine equiaxed grains areobtained in the inner side of the cross-section. Moreover, with the increase of input current, the equiaxed grain regionwidens and the grains distribute more uniformly in the circumferential direction. Meanwhile, the mechanical properties areremarkably improved by the application of electromagnetic field. When the input current is 140 A, the tensile strengthincreases 15% and the elongation increases 10%. However, the electromagnetic field has no effect on the distribution ofmicroelements.
基金supported by the Key Research and Development Program of Sichuan Province(No.2017SZ0177)Major Science and Technology Project for Environmental Governance and Ecological Protection of Sichuan Province(No.2019YFS0504)+3 种基金Major Science and Technology Project for Environmental Governance and Ecological Protection of Sichuan Province(No.2018SZDZX0024)The Key Research and Development Program of Sichuan Province(No.2020YFS0021)Strategic Biological Resources Capacity Building Project of the Chinese Academy of Sciences(No.KFJ-BRP-017-59)Major Research and Development Program of Chengdu City–Technological Innovation Research and Development Project(No.2019-YF05-02155-SN)。
文摘Urban black blooms that are primarily caused by organic carbon are deleterious environmental problems.However,detailed studies on the microbial characteristics that form urban black blooms are lacking.In this study,we observed the composition,diversity,and function of bacterial community in the overlying water and sediments during the occurrence and remediation of urban black blooms using high-throughput 16S rRNA gene amplicon sequencing analysis.First,we found that pivotal consortia in the overlying water increased significantly during the formation of black blooms,including the genera Acidovorax,Brevundimonas,Pusillimonas,and Burkholderiales involved in the degradation of refractory organics,as well as the genera Desulfovibrio,Dechloromonas,and Rhizobium related to the production of black and odorous substances.An RDA analysis revealed that chemical oxygen demand,dissolved oxygen,and oxidation reduction potential were related to the changes in microbial community composition.Furthermore,aeration was found to accelerate the removal of ammonia nitrogen and enhance the function of microbial community by stimulating the growth of order Planktomycetes during the remediation of black blooms,but aeration substantially damaged the microbial diversity and richness.Therefore,the health of the aquatic ecosystem should be comprehensively considered when aeration is applied to restore polluted waterbodies.Notably,we observed a large number of pathogenic bacteria in urban black blooms,which emphasizes the importance of treating domestic sewage so that it is harmless.Together,these findings provide new insights and a basis to prevent and manage urban black blooms.
基金The work is supported by the National Natural Science Foundation of China(Nos.11874005,21701153,51601030 and 21773023).
文摘Electrocatalytic water splitting offers a sustainable route for hydrogen production,enabling the clean and renewable alternative energy system of hydrogen economy.The scarcity and high-cost of platinum-group-metal(PGM)materials urge the exploration of high-performance non-PGM electrocatalysts.Herein,a unique hierarchical structure of NiA/2O3 with extraordinary electrocatalytic performance(e.g.t overpotentials as low as 22 mV at 20 mA·cm^-2 and 94 mV at 100 mA·cm^-2)toward hydrogen evolution reaction in alkaline electrolyte(1 M KOH)is reported.The investigation on the hierarchical NiA/2O3 with a bimodal size-distribution also offers insight of interfacial engineering that only proper NiA/2O3 interface can effectively improve H20 adsorption,H20 dissociation as well as H adsorption,for an efficient hydrogen production.
