Here we report on simultaneous lidar observations of sporadic Ni(Nis)layers and sporadic Na(Nas)layers in the atmosphere over Yanqing,Beijing(40.42°N,116.02°E)from April 2019 to October 2022.During 343 night...Here we report on simultaneous lidar observations of sporadic Ni(Nis)layers and sporadic Na(Nas)layers in the atmosphere over Yanqing,Beijing(40.42°N,116.02°E)from April 2019 to October 2022.During 343 nights of observation,68 Nis and 56 Nas were observed.The seasonal variation of Nis and Nas was also obtained,with the highest occurrence of Nis being in July(43%)and that of Nas being in June(61%).We found that the seasonal variation of Nis is similar to that of Nas and that both occur more frequently in summer than in winter.In addition,we found 23 events in which Nis and Nas occur simultaneously.The average peak altitude of Nas is approximately 1 km higher than that of Nis,and the peak density ratio of Nas to Nis is approximately 5,which is half the density ratio of the two main layers.Additionally,the strength factor for Nas is smaller than that for Nis.Through data analysis of sporadic E layers(Es),we found that Nis and Nas has a significant correlation with Es.The neutralization rates of Ni^(+)/Na^(+)were calculated according to the dissociative recombination reaction of Ni^(+)/Na^(+)and the WACCM-Ni(Whole Atmosphere Community Climate Model of Ni).The production rates of Ni and Na were estimated to be approximately 1:4.4,which is consistent with the density ratio of Nis to Nas.The results showed that the neutralization reaction of Ni+,Na+,and electrons in Es is the main reason for the formation of the Nis layer and the Nas layer.展开更多
In this study,using 3,5‑di(3′,5′‑dicarboxylphenyl)‑1H‑1,2,4‑triazole(H4L)as ligands,a gadolinia‑based organic framework complex{[GdNa(L)(H_(2)O)3]·2H_(2)O}_(n)(Gd‑Na‑MOF)was successfully designed and synthesize...In this study,using 3,5‑di(3′,5′‑dicarboxylphenyl)‑1H‑1,2,4‑triazole(H4L)as ligands,a gadolinia‑based organic framework complex{[GdNa(L)(H_(2)O)3]·2H_(2)O}_(n)(Gd‑Na‑MOF)was successfully designed and synthesized by hydrothermal method.The structure and properties were systematically characterized and tested by techniques such as single‑crystal X‑ray diffraction,powder X‑ray diffraction,thermogravimetric analysis,infrared spectroscopy,and fluorescence spectroscopy.The results indicate that this complex has a unique 3D structure,excellent thermal stability,and outstanding luminescent performance.Based on its luminescent properties,a polymer‑embedding method was employed to fabricate the Gd‑Na‑MOF into a flexible,washable composite fluorescent film,Gd‑Na‑MOF@PMMA/BMA(PMMA=polymethyl methacrylate,BMA=butyl methacrylate).This fluorescent film exhibited highly sensitive recognition capability for tyramine,with a low detection limit of 1.66μmol·L^(-1).It was used for the detection of tyramine in bananas,with a recovery rate of 96.92%‑100.26%.CCDC:2466949.展开更多
This study presents a systematic investigation of high-efficiency flexible copper indium gallium selenide(CIGS)thin-film solar cells fabricated using an optimized three-stage co-evaporation process.The research focuse...This study presents a systematic investigation of high-efficiency flexible copper indium gallium selenide(CIGS)thin-film solar cells fabricated using an optimized three-stage co-evaporation process.The research focuses on two key innovations:(1)NaF pre-deposition for controlled alkali metal doping and(2)active regulation of In/Ga evaporation timing during the initial growth stage to precisely engineer the Ga/(Ga+In)(GGI)ratio gradient throughout the absorber layer depth.Through comprehensive characterization of structural properties,elemental distributions,and device performance,we demonstrate that the synergistic combination of Na doping and tailored Ga grading effectively addresses critical challenges in flexible CIGS devices,including back-surface Ga accumulation and non-ideal bandgap profiles.Our results reveal that this dual optimization strategy significantly enhances charge carrier mobility and collection efficiency,ultimately leading to substantial improvements in overall solar cell performance.The findings establish a robust materials engineering approach for developing high-performance flexible photovoltaic devices through precise control of compositional gradients and defect passivation.展开更多
To promote CO_(2)redox kinetics on the cathode of hybrid sodium-carbon dioxide(Na-CO_(2))batteries,hollow cubic CuS nanoboxes were encapsulated in polypyrrole and polydopamine by in situ polymerization of pyrrole and ...To promote CO_(2)redox kinetics on the cathode of hybrid sodium-carbon dioxide(Na-CO_(2))batteries,hollow cubic CuS nanoboxes were encapsulated in polypyrrole and polydopamine by in situ polymerization of pyrrole and dopamine monomers,respectively,and coupled with high-temperature heat treatment to obtain nitrogen-carbon encapsulated Cu_(x)S@NC_(PPy)and Cu_(x)S@NCPDA catalysts.The results show that the encapsulation of nitrogen-doped carbon not only increases the specific surface area and improves the electron affinity but also promotes the synergistic interaction between the CuS-based active species and the defect carbon,thus providing abundant active sites for CO_(2)conversion.The electrochemical performances of the carbon-coated modified samples were all improved,especially the hybrid Na-CO_(2)battery based on Cu_(x)S@NC_(PPy),which showed a low voltage gap of 0.74 V at 0.1 mA/cm^(2)and a high power density of 3.42 mW/cm^(2).展开更多
基金supported by the Specialized Research Fund for State Key Laboratories,Chinese Meridian Project,the Specialized Research Fund for the State Key Laboratory of Solar Activity and Space Weather,postgraduate Education Reform and Quality Improvement Project of Henan Province(Grant No.YJS2024JD32)Natural Science Foundation Project of Henan Province(Grant No.242300420253)National Natural Science Foundation of China for Young Scientists(Grant No.42504156)funding.
文摘Here we report on simultaneous lidar observations of sporadic Ni(Nis)layers and sporadic Na(Nas)layers in the atmosphere over Yanqing,Beijing(40.42°N,116.02°E)from April 2019 to October 2022.During 343 nights of observation,68 Nis and 56 Nas were observed.The seasonal variation of Nis and Nas was also obtained,with the highest occurrence of Nis being in July(43%)and that of Nas being in June(61%).We found that the seasonal variation of Nis is similar to that of Nas and that both occur more frequently in summer than in winter.In addition,we found 23 events in which Nis and Nas occur simultaneously.The average peak altitude of Nas is approximately 1 km higher than that of Nis,and the peak density ratio of Nas to Nis is approximately 5,which is half the density ratio of the two main layers.Additionally,the strength factor for Nas is smaller than that for Nis.Through data analysis of sporadic E layers(Es),we found that Nis and Nas has a significant correlation with Es.The neutralization rates of Ni^(+)/Na^(+)were calculated according to the dissociative recombination reaction of Ni^(+)/Na^(+)and the WACCM-Ni(Whole Atmosphere Community Climate Model of Ni).The production rates of Ni and Na were estimated to be approximately 1:4.4,which is consistent with the density ratio of Nis to Nas.The results showed that the neutralization reaction of Ni+,Na+,and electrons in Es is the main reason for the formation of the Nis layer and the Nas layer.
文摘In this study,using 3,5‑di(3′,5′‑dicarboxylphenyl)‑1H‑1,2,4‑triazole(H4L)as ligands,a gadolinia‑based organic framework complex{[GdNa(L)(H_(2)O)3]·2H_(2)O}_(n)(Gd‑Na‑MOF)was successfully designed and synthesized by hydrothermal method.The structure and properties were systematically characterized and tested by techniques such as single‑crystal X‑ray diffraction,powder X‑ray diffraction,thermogravimetric analysis,infrared spectroscopy,and fluorescence spectroscopy.The results indicate that this complex has a unique 3D structure,excellent thermal stability,and outstanding luminescent performance.Based on its luminescent properties,a polymer‑embedding method was employed to fabricate the Gd‑Na‑MOF into a flexible,washable composite fluorescent film,Gd‑Na‑MOF@PMMA/BMA(PMMA=polymethyl methacrylate,BMA=butyl methacrylate).This fluorescent film exhibited highly sensitive recognition capability for tyramine,with a low detection limit of 1.66μmol·L^(-1).It was used for the detection of tyramine in bananas,with a recovery rate of 96.92%‑100.26%.CCDC:2466949.
基金supported by the National Key Research and Development Program of China(Grant No.2024YFB4205300)the National Natural Science Foundation of China(Grant No.52173243)+2 种基金the Natural Science Foundation of Guangdong Province(Grant No.2021A1515011409)Shenzhen&Hong Kong Joint Research Program(Grant No.SGDX20201103095605015)SIAT-CUHK Joint Laboratory of Photovoltaic Solar Energy.
文摘This study presents a systematic investigation of high-efficiency flexible copper indium gallium selenide(CIGS)thin-film solar cells fabricated using an optimized three-stage co-evaporation process.The research focuses on two key innovations:(1)NaF pre-deposition for controlled alkali metal doping and(2)active regulation of In/Ga evaporation timing during the initial growth stage to precisely engineer the Ga/(Ga+In)(GGI)ratio gradient throughout the absorber layer depth.Through comprehensive characterization of structural properties,elemental distributions,and device performance,we demonstrate that the synergistic combination of Na doping and tailored Ga grading effectively addresses critical challenges in flexible CIGS devices,including back-surface Ga accumulation and non-ideal bandgap profiles.Our results reveal that this dual optimization strategy significantly enhances charge carrier mobility and collection efficiency,ultimately leading to substantial improvements in overall solar cell performance.The findings establish a robust materials engineering approach for developing high-performance flexible photovoltaic devices through precise control of compositional gradients and defect passivation.
基金financially supported by the National Natural Science Foundation of China(No.52172264)the National Key Research and Development Program of China(No.2022YFC3900802)。
文摘To promote CO_(2)redox kinetics on the cathode of hybrid sodium-carbon dioxide(Na-CO_(2))batteries,hollow cubic CuS nanoboxes were encapsulated in polypyrrole and polydopamine by in situ polymerization of pyrrole and dopamine monomers,respectively,and coupled with high-temperature heat treatment to obtain nitrogen-carbon encapsulated Cu_(x)S@NC_(PPy)and Cu_(x)S@NCPDA catalysts.The results show that the encapsulation of nitrogen-doped carbon not only increases the specific surface area and improves the electron affinity but also promotes the synergistic interaction between the CuS-based active species and the defect carbon,thus providing abundant active sites for CO_(2)conversion.The electrochemical performances of the carbon-coated modified samples were all improved,especially the hybrid Na-CO_(2)battery based on Cu_(x)S@NC_(PPy),which showed a low voltage gap of 0.74 V at 0.1 mA/cm^(2)and a high power density of 3.42 mW/cm^(2).
