Sodium-based O3-type layered oxide materials are attractive for Sodium-ion batteries(SIBs)due to their simple synthesis,affordability,and high capacity.However,challenges remain,including limited reversible capacity a...Sodium-based O3-type layered oxide materials are attractive for Sodium-ion batteries(SIBs)due to their simple synthesis,affordability,and high capacity.However,challenges remain,including limited reversible capacity and poor cycling stability caused by detrimental phase tran-sitions during cycling and the tendency to form sodium carbonate upon air exposure.In this study,based on O3-type NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2)(NNFM),a high-entropy strategy was introduced to successfully synthesize O3-type NaNi_(0.25)Fe_(0.21)Mn_(0.18)Co_(0.21)Ti_(0.1)Mg_(0.05)O_(2)(HE-NNFM).The introduction of Co,Ti,and Mg ions increases the system's disorder,highlighting the synergistic interactions among inert atoms.The delayed phase transformation effect in high-entropy materials alleviates the destruction of the O3 structure by the insertion and extraction of sodium ions.Simultaneously,the narrower sodium layer in HE-NNFM acts as a physical barrier,effectively preventing adverse reactions with H2O and CO_(2) in the air,resulting in excellent reversibility and air stability of the HE-NNFM material.Consequently,the HE-NNFM material exhibits a reversible capacity of 110 mAh·g^(-1)with a capacity retention of 97.3%after 200 cycles at 1 C.This work provides insights into the design of high-entropy sodium layered oxides for high-power density storage systems.展开更多
以位山试验站典型农田为对象,利用位山站2005-10-10～2006-06-10日的实验观测数据,探讨了冬小麦整个生长期农田的热、碳通量特征,并运用SiB2(simple biosphere model Version2)模型对热、碳通量进行了模拟分析,结果表明,农田的热、碳通...以位山试验站典型农田为对象,利用位山站2005-10-10～2006-06-10日的实验观测数据,探讨了冬小麦整个生长期农田的热、碳通量特征,并运用SiB2(simple biosphere model Version2)模型对热、碳通量进行了模拟分析,结果表明,农田的热、碳通量在冬小麦生长过程中表现出明显的日变化,这些通量的最大值基本出现在正午前后;热、碳通量的日际变化也较明显,其中净辐射与潜热通量在冬小麦不同生长期表现为:越冬期<拔节抽穗期<灌浆成熟期;感热通量表现为:拔节抽穗期<灌浆成熟期<越冬期;而CO2通量为:越冬期<灌浆成熟期<拔节抽穗期.对以上通量及地表温度的模拟表明,SiB2模型能较好地模拟冬小麦生长期中农田热、碳通量及地表温度,净辐射、潜热通量、感热通量、CO2通量与地表温度的模拟值与观测值的一致性较好,线性相关系数R2分别达0.985、0.637、0.481、0.725、0.499与0.877,其中感热通量与CO2通量模拟偏差较大.另外,按冬小麦生长期分阶段对农田以上分量模拟结果表明,SiB2模型在冬小麦拔节抽穗期模拟效果最好,并发现模型对叶面积指数敏感.展开更多
The modeling ability of a stand-alone version of the Simple Biosphere Model 2（SiB2） was tested mainly through diagnosing the simulated latent heat（LE）,sensible heat（H）,CO2 flux,and air temperature at the Tongyu ...The modeling ability of a stand-alone version of the Simple Biosphere Model 2（SiB2） was tested mainly through diagnosing the simulated latent heat（LE）,sensible heat（H）,CO2 flux,and air temperature at the Tongyu field observation station（44°25＇N,122°52＇E,184 m elevation） of Coordinated Enhanced Observing Period（CEOP）,where the land cover is cropland and grassland.In the whole year of 2003,the canopy height and the leaf area index was variable.During non-growth period,the surface would become bare,while during the growth period,the canopy height could reach 2.0 m high over cropland and 0.8 m high over grassland,respectively,and max leaf area index could reach 4.2 and 2.4,respectively.The model was initialized with measurement and driven by half-hourly atmospheric observations.The simulation values for 2003 were compared against measurements.Results show that the model is of a good ability of simulating the hourly latent heat（LE）,sensible heat（H）,CO2 flux and temperature during the growth period.Moreover,the daily LE,H and CO2 flux simulated by SiB2 could reflect their yearly change reasonably.However,the model may overestimate the H generally.展开更多
基金support from Natural Science Foundation of China(Grant Nos.52371187)the Beijing-Tianjin-Hebei Basic Research Cooperation Special Project(B2024209048)+1 种基金the Central Government Guides Local Science and Technology Development Funds of Hebei Province(226Z4403G)the Ph.D.Research Startup Foundation of North China University of Science and Technology(No.BS2019001).
文摘Sodium-based O3-type layered oxide materials are attractive for Sodium-ion batteries(SIBs)due to their simple synthesis,affordability,and high capacity.However,challenges remain,including limited reversible capacity and poor cycling stability caused by detrimental phase tran-sitions during cycling and the tendency to form sodium carbonate upon air exposure.In this study,based on O3-type NaNi_(1/3)Fe_(1/3)Mn_(1/3)O_(2)(NNFM),a high-entropy strategy was introduced to successfully synthesize O3-type NaNi_(0.25)Fe_(0.21)Mn_(0.18)Co_(0.21)Ti_(0.1)Mg_(0.05)O_(2)(HE-NNFM).The introduction of Co,Ti,and Mg ions increases the system's disorder,highlighting the synergistic interactions among inert atoms.The delayed phase transformation effect in high-entropy materials alleviates the destruction of the O3 structure by the insertion and extraction of sodium ions.Simultaneously,the narrower sodium layer in HE-NNFM acts as a physical barrier,effectively preventing adverse reactions with H2O and CO_(2) in the air,resulting in excellent reversibility and air stability of the HE-NNFM material.Consequently,the HE-NNFM material exhibits a reversible capacity of 110 mAh·g^(-1)with a capacity retention of 97.3%after 200 cycles at 1 C.This work provides insights into the design of high-entropy sodium layered oxides for high-power density storage systems.
文摘以位山试验站典型农田为对象,利用位山站2005-10-10～2006-06-10日的实验观测数据,探讨了冬小麦整个生长期农田的热、碳通量特征,并运用SiB2(simple biosphere model Version2)模型对热、碳通量进行了模拟分析,结果表明,农田的热、碳通量在冬小麦生长过程中表现出明显的日变化,这些通量的最大值基本出现在正午前后;热、碳通量的日际变化也较明显,其中净辐射与潜热通量在冬小麦不同生长期表现为:越冬期<拔节抽穗期<灌浆成熟期;感热通量表现为:拔节抽穗期<灌浆成熟期<越冬期;而CO2通量为:越冬期<灌浆成熟期<拔节抽穗期.对以上通量及地表温度的模拟表明,SiB2模型能较好地模拟冬小麦生长期中农田热、碳通量及地表温度,净辐射、潜热通量、感热通量、CO2通量与地表温度的模拟值与观测值的一致性较好,线性相关系数R2分别达0.985、0.637、0.481、0.725、0.499与0.877,其中感热通量与CO2通量模拟偏差较大.另外,按冬小麦生长期分阶段对农田以上分量模拟结果表明,SiB2模型在冬小麦拔节抽穗期模拟效果最好,并发现模型对叶面积指数敏感.
基金supported by the National Basic Research Program of China (2006CB400506)
文摘The modeling ability of a stand-alone version of the Simple Biosphere Model 2（SiB2） was tested mainly through diagnosing the simulated latent heat（LE）,sensible heat（H）,CO2 flux,and air temperature at the Tongyu field observation station（44°25＇N,122°52＇E,184 m elevation） of Coordinated Enhanced Observing Period（CEOP）,where the land cover is cropland and grassland.In the whole year of 2003,the canopy height and the leaf area index was variable.During non-growth period,the surface would become bare,while during the growth period,the canopy height could reach 2.0 m high over cropland and 0.8 m high over grassland,respectively,and max leaf area index could reach 4.2 and 2.4,respectively.The model was initialized with measurement and driven by half-hourly atmospheric observations.The simulation values for 2003 were compared against measurements.Results show that the model is of a good ability of simulating the hourly latent heat（LE）,sensible heat（H）,CO2 flux and temperature during the growth period.Moreover,the daily LE,H and CO2 flux simulated by SiB2 could reflect their yearly change reasonably.However,the model may overestimate the H generally.
