The electronic configuration of Co cations at octahedral(Oct)sites plays a crucial role in the catalytic activity of Co_(3)O_(4)-based spinel oxides toward the oxygen evolution reaction(OER).However,there are few repo...The electronic configuration of Co cations at octahedral(Oct)sites plays a crucial role in the catalytic activity of Co_(3)O_(4)-based spinel oxides toward the oxygen evolution reaction(OER).However,there are few reports on modulating the electronic configuration of partial Co_(Oct)^(3+)(t_(2g)^(6)e_(g)^(0))to Co_(Oct)^(2+)(t_(2g)^(6)e_(g)^(1))for further promoting their OER performances.Herein,a metal-organic framework(MOF)/MXene composite material pyrolysis-reorganization strategy is developed to obtain heterogeneous Co-based mixed spinel oxides,Co_(3)O_(4)/Co_(2)TiO_(4).By regulating the pyrolysis temperature,the mesoporous structures and the electronic configuration of Co_(Oct) cations of mixed spinel oxides can be simultaneously optimized,leading to exceptional OER performances with low overpotentials of 280 mV on a glassy carbon electrode and 260 mV on Ni foam at 10 mA cm^(-2) as well as good stability in alkaline solution.The synergistic catalytic effect between Co_(Oct)^(3+)in Co_(3)O_(4) and Co_(Oct)^(2+)in Co_(2)TiO_(4) is shown to be crucial for improving the OER activity.This finding will provide a new pathway for promoting the OER activity of Co-based spinel oxides.展开更多
Polyoxometalates act as an electron sponge,processing multielectron redox reactions and acting as a fast ionic conductor.They show great potential as promising electrode materials for next-generation lithium ion batte...Polyoxometalates act as an electron sponge,processing multielectron redox reactions and acting as a fast ionic conductor.They show great potential as promising electrode materials for next-generation lithium ion batteries(LIBs).However,there are still some fundamental issues which should be solved before their application can be realized,such as determining the stable structural feature with reversible Li+ion insertion/desertion.In this work,polyoxovanadates(POVs)based materials of K_(4)Na_(2)V_(10)O_(28)·nH_(2)O(KNaV_(10))and Mg_(2)(NH_(4))2V_(10)O_(28)·nH_(2)O(MgV_(10))have been prepared and used as the electrode material for a Li+ion reservoir.The 10-core polyoxovanadate is demonstrated as a anionic building block and the 3D extended structure has been smartly tuned by counter cations.For MgV_(10),a 1D tunnel with an approximate size of 3Å×10Å was formed along the a axis by Mg^(2+)ions and[V_(10)O_(28)]^(6-)polyanions.The MgV_(10) shows a higher capacity,cycling stability,and rate performance than that of KNaV_(10) without tunnels.The capacity of MgV_(10) is about 160 mA h g^(-1) at a high discharge rate of 250 mA g^(-1),while it is only 118 mA h g^(-1) for KNaV_(10).Even after 60 discharge/charge cycles at 50 mA g^(-1),it displayed a capacity of 180 mA h g^(-1).The 1D tunnel in MgV_(10) facilitates the Li+ion transport and provides spatial Li storage sites,which promotes the electrochemical performance in LIBs.Moreover,the Mg^(2+)ions remained stable during battery cycling and promoted the 3D structure stability.This work demonstrates promising guidelines for the structural design of POVs based materials for Li storage.展开更多
Li metal is acknowledged as an ultimate anode material for high-specific-energy batteries,although its safety and practical cyclability heavily depend on the mysterious interface between Li metal and liquid electrolyt...Li metal is acknowledged as an ultimate anode material for high-specific-energy batteries,although its safety and practical cyclability heavily depend on the mysterious interface between Li metal and liquid electrolyte(LLI).However,there are substantial gaps in understanding the multiple intertwined chemical and electrochemical processes occurring on the LLI.Here,we unprecedentedly present the disentangled analyses of these processes and correlate them with Li dendrite growth by multi-scale simulation techniques combining machine-learning-driven molecular dynamics and phase-field modeling.Our simulations demonstrate a close relationship between Li dendrite growth and the interface reactions,which can be attributed to the charge transfer process.We further reveal that the behaviors of bond cleavages can be regulated by varying charge distribution at the interface.We propose that the charge transfer kinetics,revealed by the newly developed formulism of machine learning potential incorporating charge information,can act as a descriptor to explain the driving forces behind these behaviors on the LLI.This work enables new opportunities to fundamentally understand the intertwined processes occurring on the LLI and provide crucial new insights into the electrode-electrolyte interface design for next-generation high-specific-energy batteries.展开更多
To the Editor:Previous studies have reported the increased frequency of human leukocyte antigen(HLA)alleles in patients with hematological diseases,including acute myeloid leukemia(AML),acute lymphoblastic leukemia(AL...To the Editor:Previous studies have reported the increased frequency of human leukocyte antigen(HLA)alleles in patients with hematological diseases,including acute myeloid leukemia(AML),acute lymphoblastic leukemia(ALL),myelodysplastic syndrome(MDS),and aplastic anemia(AA).[1]However,there is currently a lack of large-sample research analyzing HLA blocks and haplotypes in relation to hematological diseases.HLA is inherited in the form of haplotypes,and there is a strong linkage disequilibrium between adjacent HLA loci on chromosomes.HLA-A is located within the alpha block;HLA-B and C are located within the beta block;HLADRB1,DQB1,DRB3/4/5,and DQA1 are located within the delta block;and HLA-DPA1 and DPB1 are located within the epsilon block.When the frequencies of HLA alleles increase,the alleles at other loci linked within the same block or haplotype may also exhibit increased frequencies.This study aimed to analyze whether alleles with increased frequency are located within the same block or haplotype,and to investigate whether HLA block analysis or haplotype analysis is more meaningful for association studies of hematological diseases.展开更多
Solar-induced chlorophyll fluorescence(SIF)has shown promise in estimating gross primary production(GPP);however,there is a lack of global GPP datasets directly utilizing SIF with models possessing clear expression of...Solar-induced chlorophyll fluorescence(SIF)has shown promise in estimating gross primary production(GPP);however,there is a lack of global GPP datasets directly utilizing SIF with models possessing clear expression of the biophysical and biological processes in photosynthesis.This study introduces a new global 0.05°SIF-based GPP dataset(CMLR GPP,based on Canopy-scale Mechanistic Light Reaction model)using TROPOMI observations.A modified mechanistic light response model was employed at the canopy scale to generate this dataset.The canopy qL(opened fraction of photosynthesis II reaction centers),required by the CMLR model,was parameterized using a random forest model.The CMLR GPP estimates showed a strong correlation with tower-based GPP(R^(2)=0.72)in the validation dataset,and it showed comparable performance with other global datasets such as Boreal Ecosystem Productivity Simulator(BEPS)GPP,FluxSat GPP,and GOSIF(global,OCO-2-based SIF product)GPP at a global scale.The high accuracy of CMLR GPP was consistent across various normalized difference vegetation index,vapor pressure deficit,and temperature conditions,as well as different plant functional types and most months of the year.In conclusion,CMLR GPP is a novel global GPP dataset based on mechanistic frameworks,whose availability is expected to contribute to future research in ecological and geobiological regions.展开更多
基金supported by the NSF of China(no.21971143,21805165)the 111 Project(D20015)+1 种基金the Major Research and Development Project of Hubei Three Gorges Laboratory(2022-3)ITOYMR in the Higher Education Institutions of Hubei Province(T201904).
文摘The electronic configuration of Co cations at octahedral(Oct)sites plays a crucial role in the catalytic activity of Co_(3)O_(4)-based spinel oxides toward the oxygen evolution reaction(OER).However,there are few reports on modulating the electronic configuration of partial Co_(Oct)^(3+)(t_(2g)^(6)e_(g)^(0))to Co_(Oct)^(2+)(t_(2g)^(6)e_(g)^(1))for further promoting their OER performances.Herein,a metal-organic framework(MOF)/MXene composite material pyrolysis-reorganization strategy is developed to obtain heterogeneous Co-based mixed spinel oxides,Co_(3)O_(4)/Co_(2)TiO_(4).By regulating the pyrolysis temperature,the mesoporous structures and the electronic configuration of Co_(Oct) cations of mixed spinel oxides can be simultaneously optimized,leading to exceptional OER performances with low overpotentials of 280 mV on a glassy carbon electrode and 260 mV on Ni foam at 10 mA cm^(-2) as well as good stability in alkaline solution.The synergistic catalytic effect between Co_(Oct)^(3+)in Co_(3)O_(4) and Co_(Oct)^(2+)in Co_(2)TiO_(4) is shown to be crucial for improving the OER activity.This finding will provide a new pathway for promoting the OER activity of Co-based spinel oxides.
基金financially supported by the National Natural Science Foundation of China(No.21603162 and 51671145)Tianjin Sci.&Tech.Program(17JCYBJC21500)+1 种基金major projects of new materials of Tianjin city(16ZXCLGX00120)the Fundamental Research Funds of Tianjin University of Technology.
文摘Polyoxometalates act as an electron sponge,processing multielectron redox reactions and acting as a fast ionic conductor.They show great potential as promising electrode materials for next-generation lithium ion batteries(LIBs).However,there are still some fundamental issues which should be solved before their application can be realized,such as determining the stable structural feature with reversible Li+ion insertion/desertion.In this work,polyoxovanadates(POVs)based materials of K_(4)Na_(2)V_(10)O_(28)·nH_(2)O(KNaV_(10))and Mg_(2)(NH_(4))2V_(10)O_(28)·nH_(2)O(MgV_(10))have been prepared and used as the electrode material for a Li+ion reservoir.The 10-core polyoxovanadate is demonstrated as a anionic building block and the 3D extended structure has been smartly tuned by counter cations.For MgV_(10),a 1D tunnel with an approximate size of 3Å×10Å was formed along the a axis by Mg^(2+)ions and[V_(10)O_(28)]^(6-)polyanions.The MgV_(10) shows a higher capacity,cycling stability,and rate performance than that of KNaV_(10) without tunnels.The capacity of MgV_(10) is about 160 mA h g^(-1) at a high discharge rate of 250 mA g^(-1),while it is only 118 mA h g^(-1) for KNaV_(10).Even after 60 discharge/charge cycles at 50 mA g^(-1),it displayed a capacity of 180 mA h g^(-1).The 1D tunnel in MgV_(10) facilitates the Li+ion transport and provides spatial Li storage sites,which promotes the electrochemical performance in LIBs.Moreover,the Mg^(2+)ions remained stable during battery cycling and promoted the 3D structure stability.This work demonstrates promising guidelines for the structural design of POVs based materials for Li storage.
基金supported by the National Natural Science Foundation of China(No.12426301)Shenzhen Science and Technology Research Grant(No.20231117083459001)AI for Science(AI4S)-Preferred Program,Peking University,Shenzhen,China.
文摘Li metal is acknowledged as an ultimate anode material for high-specific-energy batteries,although its safety and practical cyclability heavily depend on the mysterious interface between Li metal and liquid electrolyte(LLI).However,there are substantial gaps in understanding the multiple intertwined chemical and electrochemical processes occurring on the LLI.Here,we unprecedentedly present the disentangled analyses of these processes and correlate them with Li dendrite growth by multi-scale simulation techniques combining machine-learning-driven molecular dynamics and phase-field modeling.Our simulations demonstrate a close relationship between Li dendrite growth and the interface reactions,which can be attributed to the charge transfer process.We further reveal that the behaviors of bond cleavages can be regulated by varying charge distribution at the interface.We propose that the charge transfer kinetics,revealed by the newly developed formulism of machine learning potential incorporating charge information,can act as a descriptor to explain the driving forces behind these behaviors on the LLI.This work enables new opportunities to fundamentally understand the intertwined processes occurring on the LLI and provide crucial new insights into the electrode-electrolyte interface design for next-generation high-specific-energy batteries.
基金supported by the National Natural Science Foundation of China(No.82070180).
文摘To the Editor:Previous studies have reported the increased frequency of human leukocyte antigen(HLA)alleles in patients with hematological diseases,including acute myeloid leukemia(AML),acute lymphoblastic leukemia(ALL),myelodysplastic syndrome(MDS),and aplastic anemia(AA).[1]However,there is currently a lack of large-sample research analyzing HLA blocks and haplotypes in relation to hematological diseases.HLA is inherited in the form of haplotypes,and there is a strong linkage disequilibrium between adjacent HLA loci on chromosomes.HLA-A is located within the alpha block;HLA-B and C are located within the beta block;HLADRB1,DQB1,DRB3/4/5,and DQA1 are located within the delta block;and HLA-DPA1 and DPB1 are located within the epsilon block.When the frequencies of HLA alleles increase,the alleles at other loci linked within the same block or haplotype may also exhibit increased frequencies.This study aimed to analyze whether alleles with increased frequency are located within the same block or haplotype,and to investigate whether HLA block analysis or haplotype analysis is more meaningful for association studies of hematological diseases.
基金supported by the National Natural Science Foundation of China(grant numbers 41825002 and 42071310)supported by the Deutsche Forschungsgemeinschaft(DFG,German Research Foundation)under Germany’s Excellence Strategy-EXC 2070-390732324.
文摘Solar-induced chlorophyll fluorescence(SIF)has shown promise in estimating gross primary production(GPP);however,there is a lack of global GPP datasets directly utilizing SIF with models possessing clear expression of the biophysical and biological processes in photosynthesis.This study introduces a new global 0.05°SIF-based GPP dataset(CMLR GPP,based on Canopy-scale Mechanistic Light Reaction model)using TROPOMI observations.A modified mechanistic light response model was employed at the canopy scale to generate this dataset.The canopy qL(opened fraction of photosynthesis II reaction centers),required by the CMLR model,was parameterized using a random forest model.The CMLR GPP estimates showed a strong correlation with tower-based GPP(R^(2)=0.72)in the validation dataset,and it showed comparable performance with other global datasets such as Boreal Ecosystem Productivity Simulator(BEPS)GPP,FluxSat GPP,and GOSIF(global,OCO-2-based SIF product)GPP at a global scale.The high accuracy of CMLR GPP was consistent across various normalized difference vegetation index,vapor pressure deficit,and temperature conditions,as well as different plant functional types and most months of the year.In conclusion,CMLR GPP is a novel global GPP dataset based on mechanistic frameworks,whose availability is expected to contribute to future research in ecological and geobiological regions.
