Polyacrylonitrile-metal sulfide nanocomposites with metal sulfide（Ag2S, CuS, PbS） nanoparticles homo- geneously dispersed on the polyacrylonitrile（PAN） nanofibre were synthesized by means of electrospinning techno...Polyacrylonitrile-metal sulfide nanocomposites with metal sulfide（Ag2S, CuS, PbS） nanoparticles homo- geneously dispersed on the polyacrylonitrile（PAN） nanofibre were synthesized by means of electrospinning techno- logy combined with gas-solid reaction. A series of experiments was performed to characterize the morphology varia- tion and distribution of the nanocrystalline. The result shows that the concentration of metal salt aqueous solution affects the size and morphology of metal sulfide nanoparticles during the chelating process. Further more, these metal ions nanoparticles were attached to the surface of the nanofibre homogeneously through chelating effect which will be propitious to prevent nanoparticles from aggregation. These results suggest that the method reported here is ex- tremely effective for synthesizing PAN-metal sulfide nanocomposites which have good visible light photocatalytic activity. Further more, this method could be extended to prepare other PAN-metal halides nanocomposites, too.展开更多
The invasion of Spartina alterniflora (SA) has led to significant hydrogen sulfide (H_(2)S) production in coastal wetlands. The phytotoxic S2− plays a critical role in elemental biogeochemistry and may contribute to t...The invasion of Spartina alterniflora (SA) has led to significant hydrogen sulfide (H_(2)S) production in coastal wetlands. The phytotoxic S2− plays a critical role in elemental biogeochemistry and may contribute to the successful invasion of SA in areas contaminated with heavy metals. To explore how H_(2)S influences nutrient uptake and energy utilization in SA and the native Phragmites australis (PA) under cadmium (Cd) stress, and to uncover the mechanisms by which H_(2)S facilitates SA invasion, a hydroponic experiment was conducted. This experiment included three Cd concentrations (0, 1 and 2 mg Cd L^(−1)) and three H_(2)S treatments (inhibiting H_(2)S synthesis, simulating an external H_(2)S source and untreated control). Results revealed that H_(2)S plays a crucial role in balancing the uptake of Mg, Mn, Ca and Zn in SA, mitigating Cd-induced damage to the photosynthetic system and enhancing nutrient and energy accumulation under Cd stress. In contrast, H_(2)S was toxic to PA, increasing lipid peroxidation, inhibiting growth, and disrupting mineral uptake, particularly of Ca. This exacerbated the detrimental effects of Cd on the photosynthetic system and nutrient accumulation in PA. These results highlight that irrespective of Cd treatment, H_(2)S enhanced energy accumulation, mineral uptake, and growth in SA compared to PA, which could support the ecological niche competition within the coastal wetlands during the invasion of SA into PA habitats. Consequently, inhibiting endogenous H_(2)S synthesis in SA may offer a potential strategy for controlling its invasion.展开更多
Transition metal sulfides and oxides with suitable dielectric features have been considered as significant candidates for advanced electromagnetic wave(EMW)absorption systems.However,there is still an urgent need to r...Transition metal sulfides and oxides with suitable dielectric features have been considered as significant candidates for advanced electromagnetic wave(EMW)absorption systems.However,there is still an urgent need to realize controllable regulation of their interfacial polarization behavior.Herein,we prepared dual-phase CoFe_(2)S_(4)/CoFe_(2)O_(4)composites with an average size of~1.43μm through a hydrothermal method.The unique nanoflower morphology promoted the multiple reflection and scattering of the incident EMW,contributing to the improvement of the loss ability.By varying the temperature during the solvothermal reaction,a facile adjustment of the CoFe_(2)O_(4)to CoFe_(2)S_(4)ratio can be realized.The difference in electronegativity and band gap facilitated the directional electron transfer from CoFe_(2)O_(4)side to CoFe_(2)S_(4)side at the dual-phase heterogenous interfaces,leading to spatial charge redistribution and optimized in-plane interfacial polarization.Moreover,the different distribution of CoFe_(2)O_(4)and CoFe_(2)S_(4)phases on different nanosheets exaggerated the deviation of interlayer positive/negative charges from the original equilibrium centers,thereby contributing to the enhancement of interlayer polarization.As a result,CoFe_(2)S_(4)/CoFe_(2)O_(4)with higher dual-phase density exhibited strongest absorption intensity of-77.2 dB with an effective absorption bandwidth of 7.2 GHz at 1.8 mm.This work demonstrates the effective EMW attenuation optimization in transition metal sulfides and oxides and paves the way for modulating multiple interfacial polarization responses in inhomogeneous absorber systems.展开更多
Mineral flotation plays a pivotal role in mineral processing.The oxidation of sulfide ores can alter the surface properties of minerals,thereby optimizing their separation efficiency.This paper provides a comprehensiv...Mineral flotation plays a pivotal role in mineral processing.The oxidation of sulfide ores can alter the surface properties of minerals,thereby optimizing their separation efficiency.This paper provides a comprehensive review of the various oxidation methods applied in sulfide mineral flotation,including chemical oxidation,electrochemical oxidation,biological oxidation,thermal pretreatment,and plasma treatment.Additionally,it discusses the impact of mineral oxidation on flotation performance,focusing on modifications to surface properties such as the formation of oxidation products,changes in zeta potential,and alterations in hydrophobicity,as well as the degradation of flotation reagents and changes in reagent adsorption.However,challenges remain in the oxidation-flotation separation of sulfide minerals,including insufficient control precision of the oxidation process,environmental and cost concerns associated with certain oxidation methods,and a lack of in-depth research into the oxidation-flotation mechanism.Future advancements in oxidative flotation will focus on intelligent monitoring,precise control,composite oxidation systems,and in situ analysis to understand surface microvariations and oxidation-product relationships.Cost control will rely on the use of low-cost oxidants,durable electrodes,and energy-efficient equipment.Tailored processing solutions for complex ores integrating bioflotation,physical separation,and other technologies will enhance recovery rates and concentrate quality,promoting broader applications.展开更多
文摘Polyacrylonitrile-metal sulfide nanocomposites with metal sulfide（Ag2S, CuS, PbS） nanoparticles homo- geneously dispersed on the polyacrylonitrile（PAN） nanofibre were synthesized by means of electrospinning techno- logy combined with gas-solid reaction. A series of experiments was performed to characterize the morphology varia- tion and distribution of the nanocrystalline. The result shows that the concentration of metal salt aqueous solution affects the size and morphology of metal sulfide nanoparticles during the chelating process. Further more, these metal ions nanoparticles were attached to the surface of the nanofibre homogeneously through chelating effect which will be propitious to prevent nanoparticles from aggregation. These results suggest that the method reported here is ex- tremely effective for synthesizing PAN-metal sulfide nanocomposites which have good visible light photocatalytic activity. Further more, this method could be extended to prepare other PAN-metal halides nanocomposites, too.
基金supported by the Yellow Sea wetland project (HHSDKT202417)the Open Research Fund of State Key Laboratory of Estuarine and Coastal Research (SKLECKF202306)+2 种基金the Carbon Peak and Carbon Neutrality Technology Innovation Special Foundation of Jiangsu Province (BK20220030)Postgraduate Research&Practice Innovation Program of Jiangsu Province (SJCX22_1863)the Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment,China。
文摘The invasion of Spartina alterniflora (SA) has led to significant hydrogen sulfide (H_(2)S) production in coastal wetlands. The phytotoxic S2− plays a critical role in elemental biogeochemistry and may contribute to the successful invasion of SA in areas contaminated with heavy metals. To explore how H_(2)S influences nutrient uptake and energy utilization in SA and the native Phragmites australis (PA) under cadmium (Cd) stress, and to uncover the mechanisms by which H_(2)S facilitates SA invasion, a hydroponic experiment was conducted. This experiment included three Cd concentrations (0, 1 and 2 mg Cd L^(−1)) and three H_(2)S treatments (inhibiting H_(2)S synthesis, simulating an external H_(2)S source and untreated control). Results revealed that H_(2)S plays a crucial role in balancing the uptake of Mg, Mn, Ca and Zn in SA, mitigating Cd-induced damage to the photosynthetic system and enhancing nutrient and energy accumulation under Cd stress. In contrast, H_(2)S was toxic to PA, increasing lipid peroxidation, inhibiting growth, and disrupting mineral uptake, particularly of Ca. This exacerbated the detrimental effects of Cd on the photosynthetic system and nutrient accumulation in PA. These results highlight that irrespective of Cd treatment, H_(2)S enhanced energy accumulation, mineral uptake, and growth in SA compared to PA, which could support the ecological niche competition within the coastal wetlands during the invasion of SA into PA habitats. Consequently, inhibiting endogenous H_(2)S synthesis in SA may offer a potential strategy for controlling its invasion.
基金financially supported by Ningbo Yongjiang Talent Program(No.2024A-421-G)Ningbo Key Research and Development Program(No.2024Z210)+1 种基金Ningbo Key Laboratory of Molecular Target Screening and Application(No.2023-BZDS)Ningbo Top Medical and Health Research Program(No.2023030514)
文摘Transition metal sulfides and oxides with suitable dielectric features have been considered as significant candidates for advanced electromagnetic wave(EMW)absorption systems.However,there is still an urgent need to realize controllable regulation of their interfacial polarization behavior.Herein,we prepared dual-phase CoFe_(2)S_(4)/CoFe_(2)O_(4)composites with an average size of~1.43μm through a hydrothermal method.The unique nanoflower morphology promoted the multiple reflection and scattering of the incident EMW,contributing to the improvement of the loss ability.By varying the temperature during the solvothermal reaction,a facile adjustment of the CoFe_(2)O_(4)to CoFe_(2)S_(4)ratio can be realized.The difference in electronegativity and band gap facilitated the directional electron transfer from CoFe_(2)O_(4)side to CoFe_(2)S_(4)side at the dual-phase heterogenous interfaces,leading to spatial charge redistribution and optimized in-plane interfacial polarization.Moreover,the different distribution of CoFe_(2)O_(4)and CoFe_(2)S_(4)phases on different nanosheets exaggerated the deviation of interlayer positive/negative charges from the original equilibrium centers,thereby contributing to the enhancement of interlayer polarization.As a result,CoFe_(2)S_(4)/CoFe_(2)O_(4)with higher dual-phase density exhibited strongest absorption intensity of-77.2 dB with an effective absorption bandwidth of 7.2 GHz at 1.8 mm.This work demonstrates the effective EMW attenuation optimization in transition metal sulfides and oxides and paves the way for modulating multiple interfacial polarization responses in inhomogeneous absorber systems.
基金the Project of Zhongyuan Critical Metals Laboratory(No.GJJSGFYQ202334)Natural Science Foundation of Henan Province(No.242300420002)+1 种基金National Key Research and Development Program(NO.2020YFC1908804)National Natural Science Foundation of China(No.51804275)
文摘Mineral flotation plays a pivotal role in mineral processing.The oxidation of sulfide ores can alter the surface properties of minerals,thereby optimizing their separation efficiency.This paper provides a comprehensive review of the various oxidation methods applied in sulfide mineral flotation,including chemical oxidation,electrochemical oxidation,biological oxidation,thermal pretreatment,and plasma treatment.Additionally,it discusses the impact of mineral oxidation on flotation performance,focusing on modifications to surface properties such as the formation of oxidation products,changes in zeta potential,and alterations in hydrophobicity,as well as the degradation of flotation reagents and changes in reagent adsorption.However,challenges remain in the oxidation-flotation separation of sulfide minerals,including insufficient control precision of the oxidation process,environmental and cost concerns associated with certain oxidation methods,and a lack of in-depth research into the oxidation-flotation mechanism.Future advancements in oxidative flotation will focus on intelligent monitoring,precise control,composite oxidation systems,and in situ analysis to understand surface microvariations and oxidation-product relationships.Cost control will rely on the use of low-cost oxidants,durable electrodes,and energy-efficient equipment.Tailored processing solutions for complex ores integrating bioflotation,physical separation,and other technologies will enhance recovery rates and concentrate quality,promoting broader applications.
