Magnesium hydride(MgH_(2))is an important material for hydrogen(H_(2))storage and transportation owing to its high capacity and reversibility.However,its intrinsic properties have considerably limited its industrial a...Magnesium hydride(MgH_(2))is an important material for hydrogen(H_(2))storage and transportation owing to its high capacity and reversibility.However,its intrinsic properties have considerably limited its industrial application.In this study,the NiFe-800 catalyst as metal-organic framework(MOF)derivative was first utilized to promote the intrinsic properties of MgH_(2).Compared to pure MgH_(2),which releases1.24 wt%H_(2)in 60 min at 275℃,the MgH_(2)-10 NiFe-800 composite releases 5.85 wt%H_(2)in the same time.Even at a lower temperature of 250℃,the MgH_(2)-10 NiFe-800 composite releases 3.57 wt%H_(2),surpassing the performance of pure MgH_(2)at 275℃.Correspondingly,while pure MgH_(2)absorbs 2.08 wt%H_(2)in60 min at 125℃,the MgH_(2)-10 NiFe-800 composite absorbs 5.35 wt%H_(2)in just 1 min,Remarkably,the MgH_(2)-10 NiFe-800 composite absorbs 2.27 wt%H_(2)in 60 min at 50℃and 4.64 wt%H_(2)at 75℃.This indicates that MgH_(2)-10 NiFe-800 exhibits optimum performance with excellent kinetics at low temperatures.Furthermore,the capacity of the MgH_(2)-10 NiFe-800 composite remains largely stable after 10cycles.Moreover,the Mg_(2)Ni/Mg_(2)NiH_(4)acts as a"hydrogen pump",providing effective diffusion channels that enhance the kinetic process of the composite during cycling.Additionally,Fe0facilitates electron transfer and creates hydrogen diffusion channels and catalytic sites.Finally,carbon(C)effectively prevents particle agglomeration and maintains the cyclic stability of the composites.Consequently,the synergistic effects of Mg_(2)Ni/Mg_(2)NiH_(4),Fe^(0),and C considerably improve the kinetic properties and cycling stability of MgH_(2).This work offers an effective and valuable approach to improving the hydrogen storage efficiency in the commercial application of MgH_(2).展开更多
Phase change materials have attracted significant attention owing to their promising applications in many aspects.However,it is seriously restricted by some drawbacks such as obvious leakage,relatively low thermal con...Phase change materials have attracted significant attention owing to their promising applications in many aspects.However,it is seriously restricted by some drawbacks such as obvious leakage,relatively low thermal conductivity,and easily flame properties.Herein,a novel flame retardant form-stable composite phase change material(CPCM)with polyethylene glycol/epoxy resin/expanded graphite/magnesium hydroxide/zinc hydroxide(PEG/ER/EG/MH/ZH)has been successfully prepared and utilized in the battery module.The addition of MH and ZH(MH:ZH=1:2)as flame retardant additions can not only greatly improve the flame retardant effect but also maintain the physical and mechanical properties of the polymer.Further,the EG(5%)can provide the graphitization degree of residual char which is beneficial to building a more protective barrier.This designation of CPCM can exhibit leakage-proof,high thermal conductivity(increasing 400%-500%)and prominent flammable retardant performance.Especially at 3C discharge rate,the maximum temperature is controlled below 54.2℃and the temperature difference is maintained within 2.2℃in the battery module,which presents a superior thermal management effect.This work suggests an efficient and feasible approach toward exploiting a multifunctional phase change material for thermal management systems for electric vehicles and energy storage fields.展开更多
Plant phenology is the study of the timing of recurrent biological events and the causes of their timing with regard to biotic and abiotic forces.Plant phenology affects the structure and function of terrestrial ecosy...Plant phenology is the study of the timing of recurrent biological events and the causes of their timing with regard to biotic and abiotic forces.Plant phenology affects the structure and function of terrestrial ecosystems and determines vegetation feedback to the climate system by altering the carbon,water and energy fluxes between the vegetation and near-surface atmosphere.Therefore,an accurate simulation of plant phenology is essential to improve our understanding of the response of ecosystems to climate change and the carbon,water and energy balance of terrestrial ecosystems.Phenological studies have developed rapidly under global change conditions,while the research of phenology modeling is largely lagged.Inaccurate phenology modeling has become the primary limiting factor for the accurate simulation of terrestrial carbon and water cycles.Understanding the mechanism of phenological response to climate change and building process-based plant phenology models are thus important frontier issues.In this review,we first summarized the drivers of plant phenology and overviewed the development of plant phenology models.Finally,we addressed the challenges in the development of plant phenology models and highlighted that coupling machine learning and Bayesian calibration into process-based models could be a potential approach to improve the accuracy of phenology simulation and prediction under future global change conditions.展开更多
基金financially supported by the Natural Science Foundation of Guangdong province(2024A1515010228)the Research and demonstration application of intelligent sensing technology for lithium ion battery energy storage(SPICXJ-HTBBC-2022-01).
文摘Magnesium hydride(MgH_(2))is an important material for hydrogen(H_(2))storage and transportation owing to its high capacity and reversibility.However,its intrinsic properties have considerably limited its industrial application.In this study,the NiFe-800 catalyst as metal-organic framework(MOF)derivative was first utilized to promote the intrinsic properties of MgH_(2).Compared to pure MgH_(2),which releases1.24 wt%H_(2)in 60 min at 275℃,the MgH_(2)-10 NiFe-800 composite releases 5.85 wt%H_(2)in the same time.Even at a lower temperature of 250℃,the MgH_(2)-10 NiFe-800 composite releases 3.57 wt%H_(2),surpassing the performance of pure MgH_(2)at 275℃.Correspondingly,while pure MgH_(2)absorbs 2.08 wt%H_(2)in60 min at 125℃,the MgH_(2)-10 NiFe-800 composite absorbs 5.35 wt%H_(2)in just 1 min,Remarkably,the MgH_(2)-10 NiFe-800 composite absorbs 2.27 wt%H_(2)in 60 min at 50℃and 4.64 wt%H_(2)at 75℃.This indicates that MgH_(2)-10 NiFe-800 exhibits optimum performance with excellent kinetics at low temperatures.Furthermore,the capacity of the MgH_(2)-10 NiFe-800 composite remains largely stable after 10cycles.Moreover,the Mg_(2)Ni/Mg_(2)NiH_(4)acts as a"hydrogen pump",providing effective diffusion channels that enhance the kinetic process of the composite during cycling.Additionally,Fe0facilitates electron transfer and creates hydrogen diffusion channels and catalytic sites.Finally,carbon(C)effectively prevents particle agglomeration and maintains the cyclic stability of the composites.Consequently,the synergistic effects of Mg_(2)Ni/Mg_(2)NiH_(4),Fe^(0),and C considerably improve the kinetic properties and cycling stability of MgH_(2).This work offers an effective and valuable approach to improving the hydrogen storage efficiency in the commercial application of MgH_(2).
基金supported by the Natural Science Foundation of Guangdong province(2022A1515010161)the Guangdong Basic and Applied Basic Research Foundation(2021B1515130008)the National Natural Science Foundation of China(51977062).
文摘Phase change materials have attracted significant attention owing to their promising applications in many aspects.However,it is seriously restricted by some drawbacks such as obvious leakage,relatively low thermal conductivity,and easily flame properties.Herein,a novel flame retardant form-stable composite phase change material(CPCM)with polyethylene glycol/epoxy resin/expanded graphite/magnesium hydroxide/zinc hydroxide(PEG/ER/EG/MH/ZH)has been successfully prepared and utilized in the battery module.The addition of MH and ZH(MH:ZH=1:2)as flame retardant additions can not only greatly improve the flame retardant effect but also maintain the physical and mechanical properties of the polymer.Further,the EG(5%)can provide the graphitization degree of residual char which is beneficial to building a more protective barrier.This designation of CPCM can exhibit leakage-proof,high thermal conductivity(increasing 400%-500%)and prominent flammable retardant performance.Especially at 3C discharge rate,the maximum temperature is controlled below 54.2℃and the temperature difference is maintained within 2.2℃in the battery module,which presents a superior thermal management effect.This work suggests an efficient and feasible approach toward exploiting a multifunctional phase change material for thermal management systems for electric vehicles and energy storage fields.
基金supported by the National Natural Science Foundation of China(Grant No.31770516)the National Key Research and Development Program of China(Grant No.2017YFA06036001)+1 种基金the 111 Project(Grant No.B18006)the Fundamental Research Funds for the Central Universities(Grant No.2018EYT05)。
文摘Plant phenology is the study of the timing of recurrent biological events and the causes of their timing with regard to biotic and abiotic forces.Plant phenology affects the structure and function of terrestrial ecosystems and determines vegetation feedback to the climate system by altering the carbon,water and energy fluxes between the vegetation and near-surface atmosphere.Therefore,an accurate simulation of plant phenology is essential to improve our understanding of the response of ecosystems to climate change and the carbon,water and energy balance of terrestrial ecosystems.Phenological studies have developed rapidly under global change conditions,while the research of phenology modeling is largely lagged.Inaccurate phenology modeling has become the primary limiting factor for the accurate simulation of terrestrial carbon and water cycles.Understanding the mechanism of phenological response to climate change and building process-based plant phenology models are thus important frontier issues.In this review,we first summarized the drivers of plant phenology and overviewed the development of plant phenology models.Finally,we addressed the challenges in the development of plant phenology models and highlighted that coupling machine learning and Bayesian calibration into process-based models could be a potential approach to improve the accuracy of phenology simulation and prediction under future global change conditions.
