In recent years,manganese-based oxides as an advanced class of cathode materials for zinc-ion batteries(ZIBs)have attracted a great deal of attentions from numerous researchers.However,their slow reaction kinetics,lim...In recent years,manganese-based oxides as an advanced class of cathode materials for zinc-ion batteries(ZIBs)have attracted a great deal of attentions from numerous researchers.However,their slow reaction kinetics,limited active sites and poor electrical conductivity inevitably give rise to the severe performance degradation.To solve these problems,herein,we introduce abundant oxygen vacancies into the flower-likeδ-MnO_(2)nanostructure and effectively modulate the vacancy defects to reach the optimal level(δ-MnO_(2)-x-2.0).The smart design intrinsically tunes the electronic structure,guarantees ion chemisorption-desorption equilibrium and increases the electroactive sites,which not only effectively accelerates charge transfer rate during reaction processes,but also endows more redox reactions,as verified by first-principle calculations.These merits can help the fabricatedδ-MnO_(2)-x-2.0 cathode to present a large specific capacity of 551.8 mAh g^(-1) at 0.5 A g^(-1),high-rate capability of 262.2 mAh g^(-1) at 10 A g^(-1) and an excellent cycle lifespan(83%of capacity retention after 1500 cycles),which is far superior to those of the other metal compound cathodes.In addition,the charge/discharge mechanism of theδ-MnO_(2)-x-2.0 cathode has also been elaborated through ex situ techniques.This work opens up a new pathway for constructing the next-generation high-performance ZIBs cathode materials.展开更多
Dolichospermum spp.and Microcystis spp.are two common cyanobacteria that form blooms in the Changjiang(Yangtze)River basin,but the environmental conditions for their succession in large lakes are still unclear.Based o...Dolichospermum spp.and Microcystis spp.are two common cyanobacteria that form blooms in the Changjiang(Yangtze)River basin,but the environmental conditions for their succession in large lakes are still unclear.Based on daily monitoring data from Meiliang Bay in Taihu Lake from March to June,2016-2018,we studied the environmental conditions necessary for the succession of these two cyanobacteria.Results show that from March to June,the dominant genera of cyanobacteria experienced succession and co-dominated with Microcystis.The succession process included three stages.In StageⅠ,the biomass of Dolichospermum and Microcystis was similar(March),but Dolichospermum was dominant for most of the period.In StageⅡ,dominance alternated between Dolichospermum and Microcystis(April to mid-May).In StageⅢ,the biomass of Microcystis dominated(mid-May to June).In addition,temperature and nutrients across the three stages varied significantly.The average temperature increased continuously from 10.9 to 18.4,and to 24.2℃.The total nitrogen content decreased from 2.87 to 2.40,and to 1.86 mg/L.The total phosphorus content increased from 0.08 to 0.09,and to 0.12 mg/L.Correlation analysis revealed that Microcystis biomass was positively correlated with temperature and total phosphorus.Dolichospermum biomass was positively correlated with total nitrogen.Classification and regression tree displays that when the temperature was below 18.1℃,Dolichospermum dominated;above 18.1℃,Microcystis took over.Further analysis revealed that when temperature reached 18℃,the biomass of Microcystis increased exponentially,and the biomass of Dolichospermum exhibited a Gaussian distribution trend.This finding indicated that temperature was the key factor in the succession of Dolichospermum and Microcystis in nutrient-rich shallow lakes.As nitrogen and phosphorus concentrations decrease,the dominant species of cyanobacteria will diversify its development.The results of this study provide a foundation for risk prediction and control strategies f展开更多
During our investigation of diatom biodiversity in Xizang,two species exhibited unique morphological features discriminative from all previously known genera.Herein we describe these two species and describe as new th...During our investigation of diatom biodiversity in Xizang,two species exhibited unique morphological features discriminative from all previously known genera.Herein we describe these two species and describe as new the genus,Spargeria gen.nov.The new genus features narrow to wide rectangular valves,narrow valve mantles,filiform raphe branches that occur on the valve face only,terminal raphe fissures straight or slightly deflected to same side,bow-tie shaped central areas,chambered striae present on the valve face only,being absent from the mantle,wider striae near the axial area and very narrow near the margin,multiseriate striae with small and round areolae that are occluded externally.Comparatively,Spargeria zhuii sp.nov.has larger and robust valves,radiate striae,with one divergent stria near the apices,while Spargeria chenia sp.nov.is smaller,with narrow valves,striae slightly radiate in the middle,becoming convergent or parallel near apices.This new genus belongs to the family Pinnulariaceae,and it was compared and contrasted with other genera of this family.Our work suggests the need for continued studies to document the biodiversity of diatoms in Xizang.展开更多
It is challenging to efficiently and economically recycle many lithium-ion batteries(LIBs)because of the low valuation of commodity metals and materials,such as LiFePO_(4).There are millions of tons of spent LIBs wher...It is challenging to efficiently and economically recycle many lithium-ion batteries(LIBs)because of the low valuation of commodity metals and materials,such as LiFePO_(4).There are millions of tons of spent LIBs where the barrier to recycling is economical,and to make recycling more feasible,it is required that the value of the processed recycled material exceeds the value of raw commodity materials.The presented research illustrates improved profitability and economics for recycling spent LIBs by utilizing the surplus energy in lithiated graphite to drive the preparation of organolithiums to add value to the recycled lithium materials.This study methodology demonstrates that the surplus energy of lithiated graphite obtained from spent LIBs can be utilized to prepare high-value organolithiums,thereby significantly improving the economic profitability of LIB recycling.Organolithiums(R-O-Li and R-Li)were prepared using alkyl alcohol(R-OH)and alkyl bromide(R-Br)as substrates,where R includes varying hindered alkyl hydrocarbons.The organolithiums extracted from per kilogram of recycled LIBs can increase the economic value between$29.5 and$226.5 kg^(−1) cell.The value of the organolithiums is at least 5.4 times the total theoretical value of spent materials,improving the profitability of recycling LIBs over traditional pyrometallurgical($0.86 kg^(−1) cell),hydrometallurgical($1.00 kg^(−1) cell),and physical direct recycling methods($5.40 kg^(−1) cell).展开更多
基金supported by the National Natural Science Foundation of China under Grant Nos. 52072196, 52002200, 52102106 and 52002199Major Basic Research Program of the Natural Science Foundation of Shandong Province under Grant No. ZR2020ZD09+2 种基金the Natural Science Foundation of Shandong Province under Grant No. ZR2020QE063the Innovation and Technology Program of Shandong Province under Grant No. 2020KJA004the Taishan Scholars Program of Shandong Province under Grant No. ts201511034
文摘In recent years,manganese-based oxides as an advanced class of cathode materials for zinc-ion batteries(ZIBs)have attracted a great deal of attentions from numerous researchers.However,their slow reaction kinetics,limited active sites and poor electrical conductivity inevitably give rise to the severe performance degradation.To solve these problems,herein,we introduce abundant oxygen vacancies into the flower-likeδ-MnO_(2)nanostructure and effectively modulate the vacancy defects to reach the optimal level(δ-MnO_(2)-x-2.0).The smart design intrinsically tunes the electronic structure,guarantees ion chemisorption-desorption equilibrium and increases the electroactive sites,which not only effectively accelerates charge transfer rate during reaction processes,but also endows more redox reactions,as verified by first-principle calculations.These merits can help the fabricatedδ-MnO_(2)-x-2.0 cathode to present a large specific capacity of 551.8 mAh g^(-1) at 0.5 A g^(-1),high-rate capability of 262.2 mAh g^(-1) at 10 A g^(-1) and an excellent cycle lifespan(83%of capacity retention after 1500 cycles),which is far superior to those of the other metal compound cathodes.In addition,the charge/discharge mechanism of theδ-MnO_(2)-x-2.0 cathode has also been elaborated through ex situ techniques.This work opens up a new pathway for constructing the next-generation high-performance ZIBs cathode materials.
基金Supported by the National Natural Science Foundation of China(No.42007159)the Network Security and Informatization Project of Chinese Academy of Sciences(No.CAS-WX2021SF-050402)+2 种基金the Water Science and Technology Project of Jiangsu Province(No.2020004)the Key Project of Nanjing Institute of Geography and LimnologyChinese Academy of Sciences(No.NIGLAS2022GS03)。
文摘Dolichospermum spp.and Microcystis spp.are two common cyanobacteria that form blooms in the Changjiang(Yangtze)River basin,but the environmental conditions for their succession in large lakes are still unclear.Based on daily monitoring data from Meiliang Bay in Taihu Lake from March to June,2016-2018,we studied the environmental conditions necessary for the succession of these two cyanobacteria.Results show that from March to June,the dominant genera of cyanobacteria experienced succession and co-dominated with Microcystis.The succession process included three stages.In StageⅠ,the biomass of Dolichospermum and Microcystis was similar(March),but Dolichospermum was dominant for most of the period.In StageⅡ,dominance alternated between Dolichospermum and Microcystis(April to mid-May).In StageⅢ,the biomass of Microcystis dominated(mid-May to June).In addition,temperature and nutrients across the three stages varied significantly.The average temperature increased continuously from 10.9 to 18.4,and to 24.2℃.The total nitrogen content decreased from 2.87 to 2.40,and to 1.86 mg/L.The total phosphorus content increased from 0.08 to 0.09,and to 0.12 mg/L.Correlation analysis revealed that Microcystis biomass was positively correlated with temperature and total phosphorus.Dolichospermum biomass was positively correlated with total nitrogen.Classification and regression tree displays that when the temperature was below 18.1℃,Dolichospermum dominated;above 18.1℃,Microcystis took over.Further analysis revealed that when temperature reached 18℃,the biomass of Microcystis increased exponentially,and the biomass of Dolichospermum exhibited a Gaussian distribution trend.This finding indicated that temperature was the key factor in the succession of Dolichospermum and Microcystis in nutrient-rich shallow lakes.As nitrogen and phosphorus concentrations decrease,the dominant species of cyanobacteria will diversify its development.The results of this study provide a foundation for risk prediction and control strategies f
基金the National Natural Science Foundation of China(Nos.31970213,31870187)the Natural Science Foundation of Heilongjiang Province for Excellent Young Scholars(No.YQ2020C032)the Second Tibetan Plateau Scientific Expedition and Research Program(No.2019QZKK0304)。
文摘During our investigation of diatom biodiversity in Xizang,two species exhibited unique morphological features discriminative from all previously known genera.Herein we describe these two species and describe as new the genus,Spargeria gen.nov.The new genus features narrow to wide rectangular valves,narrow valve mantles,filiform raphe branches that occur on the valve face only,terminal raphe fissures straight or slightly deflected to same side,bow-tie shaped central areas,chambered striae present on the valve face only,being absent from the mantle,wider striae near the axial area and very narrow near the margin,multiseriate striae with small and round areolae that are occluded externally.Comparatively,Spargeria zhuii sp.nov.has larger and robust valves,radiate striae,with one divergent stria near the apices,while Spargeria chenia sp.nov.is smaller,with narrow valves,striae slightly radiate in the middle,becoming convergent or parallel near apices.This new genus belongs to the family Pinnulariaceae,and it was compared and contrasted with other genera of this family.Our work suggests the need for continued studies to document the biodiversity of diatoms in Xizang.
基金National Natural Science Foundation of China,Grant/Award Number:51232005Key-Area Research and Development Program of Guangdong Province,Grant/Award Number:2020B090919003+1 种基金Joint Fund of the National Natural Science Foundation of China,Grant/Award Number:U1401243Shenzhen Technical Plan Project,Grant/Award Number:CYJ20170412170911187。
文摘It is challenging to efficiently and economically recycle many lithium-ion batteries(LIBs)because of the low valuation of commodity metals and materials,such as LiFePO_(4).There are millions of tons of spent LIBs where the barrier to recycling is economical,and to make recycling more feasible,it is required that the value of the processed recycled material exceeds the value of raw commodity materials.The presented research illustrates improved profitability and economics for recycling spent LIBs by utilizing the surplus energy in lithiated graphite to drive the preparation of organolithiums to add value to the recycled lithium materials.This study methodology demonstrates that the surplus energy of lithiated graphite obtained from spent LIBs can be utilized to prepare high-value organolithiums,thereby significantly improving the economic profitability of LIB recycling.Organolithiums(R-O-Li and R-Li)were prepared using alkyl alcohol(R-OH)and alkyl bromide(R-Br)as substrates,where R includes varying hindered alkyl hydrocarbons.The organolithiums extracted from per kilogram of recycled LIBs can increase the economic value between$29.5 and$226.5 kg^(−1) cell.The value of the organolithiums is at least 5.4 times the total theoretical value of spent materials,improving the profitability of recycling LIBs over traditional pyrometallurgical($0.86 kg^(−1) cell),hydrometallurgical($1.00 kg^(−1) cell),and physical direct recycling methods($5.40 kg^(−1) cell).
