As the loss of active material Mg may affect electrode’s discharge capacity and the cycling stability, a more refined mechanism study on cycling capacity degradation should be made. The present investigation is based...As the loss of active material Mg may affect electrode’s discharge capacity and the cycling stability, a more refined mechanism study on cycling capacity degradation should be made. The present investigation is based on the supposition that the capacity degradation of the binary Mg50Ni50 alloy and ternary Mg45Cu5Ni50 alloy electrodes is solely due to the corrosion of Mg, the active hydrogen storage element. That means amount of capacity degradation is determined by the corrosion current time, which is also the time of operation. The corrosion current J corr dependence on cycling time was deduced. A mathematic relation between the cycling capacity retention C N / C 1 (%) and the duration of operation was also deduced. The data calculated from the equations deduced agree well with those of the experiment result. The loss of the active hydrogen absorbing element Mg is proved to be the main cause for cycling capacity deterioration in the present investigation.展开更多
Ternary nanocomposites of CuxZnySnzS(x+y+z)are considered as an emerging potential candidate as electrode materials for energy storage devices due to the considerable interlayer spaces and tunnels in its crystal struc...Ternary nanocomposites of CuxZnySnzS(x+y+z)are considered as an emerging potential candidate as electrode materials for energy storage devices due to the considerable interlayer spaces and tunnels in its crystal structures with excellent conducting ability.Recently,this nanocomposite used as anode material for Li-ion battery has been reported,but there is lim让ed research on让s application in supercapacitors which is considered a complementary energy storage device to battery.In this work,flower-like Cu5Sn2S7/ZnS and pristine Cu5Sn2S7 nanocomposite were prepared via a facile hydrothermal method.The electrochemical tests showed that the Cu5Sn2S7/ZnS nanocomposite exhibited better performance than pristine Cu5Zn2S7,suggesting that the existence of ZnS could significantly enhance the electrochemical performance of Cu5Sn2S7,with the good capacitance of 200 F/g at the current density of 1 A/g.Furthermore 170 F/g was obtained at the large current density of 10 A/g.Supercapacitors demonstrated energy density of 11.08 Wh/kg with power density 461 W/kg or 9.67 Wh/kg at power density of 4615 W/kg.展开更多
Ti-Zr-Cu alloy has garnered signifcant attention in the feld of dental implants due to its excellent biocompatibility,antibacterial properties,and potentially controllable mechanical properties.However,two critical ch...Ti-Zr-Cu alloy has garnered signifcant attention in the feld of dental implants due to its excellent biocompatibility,antibacterial properties,and potentially controllable mechanical properties.However,two critical challenges remain in the selective laser melting(SLM)fabrication of Ti-Zr-Cu alloy:First,the high thermal conductivity of the Cu element tends to destabilize the solidifcation behavior of the molten pool,leading to uncontrollable pore defect evolution;Second,the infuence of process parameters on the synergistic efects of zirconium solution strengthening and copper precipitation strengthening is not well understood,hindering precise control over the material's mechanical properties.To address these issues,this study systematically elucidates the quantitative impact of energy input on the defect formation mechanisms and strengthening efects in the SLM processing of Ti15Zr5Cu alloy.By optimizing laser power(120–200 W)and scanning speed(450–1200 mm/s)through a full-factor experimental design,we comprehensively analyze the efects of energy input on defect morphology,microstructure evolution,and mechanical performance.The results demonstrate that as energy density decreases,defect types transition from spherical pores to irregular pores,signifcantly infuencing mechanical properties.Based on the defect evolution trends,three distinct energy density regions are identifed:the high-energy region,the lowenergy region,and the transition region.Under the optimal processing conditions of a laser power of 180 W and a scanning speed of 1200 mm/s,the Ti15Zr5Cu alloy exhibits a relative density of 99.998%,a tensile strength of 1490±11 MPa,and an elongation at break of 6.0%±0.5%.These properties ensure that the material satisfes the stringent requirements for high strength in narrow-diameter implants used in the maxilloanterior region.This study provides theoretical and experimental support for the process-property optimization of Ti-Zr-Cu alloys in additive manufacturing and promotes their application in the fabrication of high-performance,antibacterial dental implants.展开更多
This study employed a wet impregnation method to synthesize five types of Cu/HZSM-5 adsorbents with Si/Al ratios of 25,50,85,200,and 300,used for the removal of H_(2)S in lowtemperature,low-oxygen environments.The imp...This study employed a wet impregnation method to synthesize five types of Cu/HZSM-5 adsorbents with Si/Al ratios of 25,50,85,200,and 300,used for the removal of H_(2)S in lowtemperature,low-oxygen environments.The impact of different Si/Al ratios on the adsorption oxidative performance of Cu_(30)/HZSM-5–85 adsorbents was investigated.According to the performance test results,Cu_(30)/HZSM-5–85 exhibited the highest breakthrough capacity,reaching 231.75 mg H_(2)S/g_(sorbent).Cu/HZSM-5 sorbent maintains a strong ability to remove H_(2)S even under humid conditions and shows excellent water resistance.XRD,BET,and XPS results revealed that CuO is the primary active species,with Cu_(30)/HZSM-5–85 having the largest surface area and highest CuO content,providing more active sites for H_(2)S adsorption.H_(2)-TPR and O_(2)-TPD results confirmed that Cu_(30)/HZSM-5–85 sorbent exhibits outstanding redox properties and oxygen storage capacity,contributing to excellent oxygen transferability in the molecular sieve adsorption-oxidation process.With notable characteristics such as a large surface area,high desulfurization efficiency,and water resistance,Cu_(30)/HZSM-5–85 sorbents hold significant importance for industrial applications.展开更多
文摘As the loss of active material Mg may affect electrode’s discharge capacity and the cycling stability, a more refined mechanism study on cycling capacity degradation should be made. The present investigation is based on the supposition that the capacity degradation of the binary Mg50Ni50 alloy and ternary Mg45Cu5Ni50 alloy electrodes is solely due to the corrosion of Mg, the active hydrogen storage element. That means amount of capacity degradation is determined by the corrosion current time, which is also the time of operation. The corrosion current J corr dependence on cycling time was deduced. A mathematic relation between the cycling capacity retention C N / C 1 (%) and the duration of operation was also deduced. The data calculated from the equations deduced agree well with those of the experiment result. The loss of the active hydrogen absorbing element Mg is proved to be the main cause for cycling capacity deterioration in the present investigation.
基金the support via Postgraduate Research Award of Queensland University of Technology(QUTPRA)
文摘Ternary nanocomposites of CuxZnySnzS(x+y+z)are considered as an emerging potential candidate as electrode materials for energy storage devices due to the considerable interlayer spaces and tunnels in its crystal structures with excellent conducting ability.Recently,this nanocomposite used as anode material for Li-ion battery has been reported,but there is lim让ed research on让s application in supercapacitors which is considered a complementary energy storage device to battery.In this work,flower-like Cu5Sn2S7/ZnS and pristine Cu5Sn2S7 nanocomposite were prepared via a facile hydrothermal method.The electrochemical tests showed that the Cu5Sn2S7/ZnS nanocomposite exhibited better performance than pristine Cu5Zn2S7,suggesting that the existence of ZnS could significantly enhance the electrochemical performance of Cu5Sn2S7,with the good capacitance of 200 F/g at the current density of 1 A/g.Furthermore 170 F/g was obtained at the large current density of 10 A/g.Supercapacitors demonstrated energy density of 11.08 Wh/kg with power density 461 W/kg or 9.67 Wh/kg at power density of 4615 W/kg.
基金supported by the National Natural Science Foundation of China(Nos.52401178 and U24A20713)the IMR Innovation Fund(No.2024-PY06)the CAS-WEGO Research and Development Plan Project.
文摘Ti-Zr-Cu alloy has garnered signifcant attention in the feld of dental implants due to its excellent biocompatibility,antibacterial properties,and potentially controllable mechanical properties.However,two critical challenges remain in the selective laser melting(SLM)fabrication of Ti-Zr-Cu alloy:First,the high thermal conductivity of the Cu element tends to destabilize the solidifcation behavior of the molten pool,leading to uncontrollable pore defect evolution;Second,the infuence of process parameters on the synergistic efects of zirconium solution strengthening and copper precipitation strengthening is not well understood,hindering precise control over the material's mechanical properties.To address these issues,this study systematically elucidates the quantitative impact of energy input on the defect formation mechanisms and strengthening efects in the SLM processing of Ti15Zr5Cu alloy.By optimizing laser power(120–200 W)and scanning speed(450–1200 mm/s)through a full-factor experimental design,we comprehensively analyze the efects of energy input on defect morphology,microstructure evolution,and mechanical performance.The results demonstrate that as energy density decreases,defect types transition from spherical pores to irregular pores,signifcantly infuencing mechanical properties.Based on the defect evolution trends,three distinct energy density regions are identifed:the high-energy region,the lowenergy region,and the transition region.Under the optimal processing conditions of a laser power of 180 W and a scanning speed of 1200 mm/s,the Ti15Zr5Cu alloy exhibits a relative density of 99.998%,a tensile strength of 1490±11 MPa,and an elongation at break of 6.0%±0.5%.These properties ensure that the material satisfes the stringent requirements for high strength in narrow-diameter implants used in the maxilloanterior region.This study provides theoretical and experimental support for the process-property optimization of Ti-Zr-Cu alloys in additive manufacturing and promotes their application in the fabrication of high-performance,antibacterial dental implants.
基金supported by the National Natural Science Foundation of China(Nos.52270106 and 22266021)Yunnan Major Scientific and Technological Projects(No.202202AG050005)Yunnan Fundamental Research Projects(No.202201AT070116).
文摘This study employed a wet impregnation method to synthesize five types of Cu/HZSM-5 adsorbents with Si/Al ratios of 25,50,85,200,and 300,used for the removal of H_(2)S in lowtemperature,low-oxygen environments.The impact of different Si/Al ratios on the adsorption oxidative performance of Cu_(30)/HZSM-5–85 adsorbents was investigated.According to the performance test results,Cu_(30)/HZSM-5–85 exhibited the highest breakthrough capacity,reaching 231.75 mg H_(2)S/g_(sorbent).Cu/HZSM-5 sorbent maintains a strong ability to remove H_(2)S even under humid conditions and shows excellent water resistance.XRD,BET,and XPS results revealed that CuO is the primary active species,with Cu_(30)/HZSM-5–85 having the largest surface area and highest CuO content,providing more active sites for H_(2)S adsorption.H_(2)-TPR and O_(2)-TPD results confirmed that Cu_(30)/HZSM-5–85 sorbent exhibits outstanding redox properties and oxygen storage capacity,contributing to excellent oxygen transferability in the molecular sieve adsorption-oxidation process.With notable characteristics such as a large surface area,high desulfurization efficiency,and water resistance,Cu_(30)/HZSM-5–85 sorbents hold significant importance for industrial applications.
