Li2MnSiO4 has an extremely high theoretical capacity of 332 mAh?g?1. However, only around half of this capacity has been realized in practice and the capacity retention during cycling is also low. In this study, Li2Mn...Li2MnSiO4 has an extremely high theoretical capacity of 332 mAh?g?1. However, only around half of this capacity has been realized in practice and the capacity retention during cycling is also low. In this study, Li2MnSiO4/carbon composite nanofibers were prepared by a combination of electrospinning and heat treatment. The one-dimensional continuous carbon nanofiber matrix serves as long-distance conductive pathways for both electrons and ions. The composite nanofiber structure avoids the aggregation of Li2MnSiO4 particles, which in turn enhances the electrode conductivity and promotes the reaction kinetics. The resultant Li2MnSiO4/carbon composite nanofibers were used as the cathode material for Li-ion batteries, and they delivered high charge and discharge capacities of 218 and 185 mAh?g?1, respectively, at the second cycle. In addition, the capacity retention of Li2MnSiO4 at the first 20th cycles increased from 37% to 54% in composite nanofibers.展开更多
Van der Waals(VDW)heterojunctions in a 2D/2D contact provide the highest area for the separation and transfer of charge carriers.In this work,a top-down strategy with a gas erosion process was employed to fabricate a ...Van der Waals(VDW)heterojunctions in a 2D/2D contact provide the highest area for the separation and transfer of charge carriers.In this work,a top-down strategy with a gas erosion process was employed to fabricate a 2D/2D carbon nitride VDW heterojunction in carbon nitride(g-C_(3)N_(4))with carbon-rich carbon nitride.The created 2D semiconducting channel in the VDW structure exhibits enhanced electric field exposure and radiation absorption,which facilitates the separation of the charge carriers and their mobility.Consequently,compared with bulk g-C_(3)N_(4)and its nanosheets,the photocatalytic performance of the fabricated carbon nitride VDW heterojunction in the water splitting reaction to hydrogen is improved by 8.6 and 3.3 times,respectively,while maintaining satisfactory photo-stability.Mechanistically,the finite element method(FEM)was employed to evaluate and clarify the contributions of the formation of VDW heterojunction to enhanced photocatalysis,in agreement quantitatively with experimental ones.This study provides a new and effective strategy for the modification and more insights to performance improvement on polymeric semiconductors in photocatalysis and energy conversion.展开更多
Heterotopic ossification(HO)is a debilitating condition characterized by the pathologic formation of ectopic bone.HO occurs commonly following orthopedic surgeries,burns,and neurologic injuries.While surgical excision...Heterotopic ossification(HO)is a debilitating condition characterized by the pathologic formation of ectopic bone.HO occurs commonly following orthopedic surgeries,burns,and neurologic injuries.While surgical excision may provide palliation,the procedure is often burdened with significant intra-operative blood loss due to a more robust contribution of blood supply to the pathologic bone than to native bone.Based on these clinical observations,we set out to examine the role of vascular signaling in HO.Vascular endothelial growth factor A(VEGFA)has previously been shown to be a crucial pro-angiogenic and pro-osteogenic cue during normal bone development and homeostasis.Our findings,using a validated mouse model of HO,demonstrate that HO lesions are highly vascular,and that VEGFA is critical to ectopic bone formation,despite lacking a contribution of endothelial cells within the developing anlagen.展开更多
Heteroatom doping has emerged as a prevailing strategy to enhance the storage of sodium ions in carbon materials.However,the underlying mechanism governing the performance enhancement remains undisclosed.Herein,we fab...Heteroatom doping has emerged as a prevailing strategy to enhance the storage of sodium ions in carbon materials.However,the underlying mechanism governing the performance enhancement remains undisclosed.Herein,we fabricated N/S co-doped carbon beaded fibers(S-N-CBFs),which exhibited glorious rate performance and durableness in Na+storage,showcasing no obvious capacity decay even after 3500 cycles.Furthermore,when used as anodes in sodium-ion capacitors,the S-N-CBFs delivered exceptional results,boasting a high energy density of 225 Wh·kg^(-1),superior power output of 22500 W·kg^(-1),and outstanding cycling stability with a capacity attenuation of merely 0.014%per cycle after 4000 cycles at 2 A·g^(-1).Mechanistic investigations revealed that the incorporation of both pyridinic N and pyrrolic N into the carbon matrix of S-N-CBFs induced internal electric fields(IEFs),with the former IEF being stronger than the latter,in conjunction with the doped S atom.Density functional theory calculations further unveiled that the intensity of the IEF directly influenced the adsorption of Na+,thereby resulting in the exceptional performances of S-N-CBFs as sodium-ion storage materials.This work uncovers the pivotal role of IEF in regulating the electronic structure of carbon materials and enhancing their Na^(+)storage capabilities,providing valuable insights for the development of more advanced electrode materials.展开更多
Strategical elements,such as rare earth elements,play a crucial role in the industry,especially in producing high-tech materials.Major global industries have developed a strong dependence on rare earth materials.Every...Strategical elements,such as rare earth elements,play a crucial role in the industry,especially in producing high-tech materials.Major global industries have developed a strong dependence on rare earth materials.Every year,there are innovations in industries such as modern technology,green energy,or communications technology,which need more strategic metals to improve investment profitability.This article reviews advances in rare earth separation methods and techniques to guide and recommend the best extractants,depending on leaching conditions and the final target product.Each method for separating and extracting agents is individually revised in terms of the mechanism and interaction of providing rare earth elements.This paper also evaluates past and current trends of these methods and technical extractants and identifies their strengths and weaknesses.展开更多
文摘Li2MnSiO4 has an extremely high theoretical capacity of 332 mAh?g?1. However, only around half of this capacity has been realized in practice and the capacity retention during cycling is also low. In this study, Li2MnSiO4/carbon composite nanofibers were prepared by a combination of electrospinning and heat treatment. The one-dimensional continuous carbon nanofiber matrix serves as long-distance conductive pathways for both electrons and ions. The composite nanofiber structure avoids the aggregation of Li2MnSiO4 particles, which in turn enhances the electrode conductivity and promotes the reaction kinetics. The resultant Li2MnSiO4/carbon composite nanofibers were used as the cathode material for Li-ion batteries, and they delivered high charge and discharge capacities of 218 and 185 mAh?g?1, respectively, at the second cycle. In addition, the capacity retention of Li2MnSiO4 at the first 20th cycles increased from 37% to 54% in composite nanofibers.
基金the National Natural Science Foundation of China(51676096)supported by the Australian Research Council(DP170104264 and DP190103548).
文摘Van der Waals(VDW)heterojunctions in a 2D/2D contact provide the highest area for the separation and transfer of charge carriers.In this work,a top-down strategy with a gas erosion process was employed to fabricate a 2D/2D carbon nitride VDW heterojunction in carbon nitride(g-C_(3)N_(4))with carbon-rich carbon nitride.The created 2D semiconducting channel in the VDW structure exhibits enhanced electric field exposure and radiation absorption,which facilitates the separation of the charge carriers and their mobility.Consequently,compared with bulk g-C_(3)N_(4)and its nanosheets,the photocatalytic performance of the fabricated carbon nitride VDW heterojunction in the water splitting reaction to hydrogen is improved by 8.6 and 3.3 times,respectively,while maintaining satisfactory photo-stability.Mechanistically,the finite element method(FEM)was employed to evaluate and clarify the contributions of the formation of VDW heterojunction to enhanced photocatalysis,in agreement quantitatively with experimental ones.This study provides a new and effective strategy for the modification and more insights to performance improvement on polymeric semiconductors in photocatalysis and energy conversion.
基金B.L.:Supported by funding from NIH/National Institute of Arthritis and Musculoskeletal and Skin Diseases NIH1R01AR071379American College of Surgeons Clowes Award.D.M.S.:Supported by Plastic Surgery Foundation Resident Research Award+6 种基金M.S.:Supported by Plastic Surgery Foundation National Endowment AwardC.H.:Supported by Howard Hughes Medical Institute Medical Research FellowshipJ.L.:Supported by Vascular Surgery T32 5-T32-HL-076123–14A.W.J.:Supported by the NIH/NIAMS(R01 AR070773,K08 AR068316,S10OD016374)the Orthopedic Research and Education Foundation with funding provided by the Maryland Stem Cell Research Foundation,and the Musculoskeletal Transplant FoundationP.B.Y.:Supported by funding from NIH/NIAMS R01 AR057374 and NHLBI R01 HL131910Y.M.:Supported by funding from NIH/NIDCR R01 DE020843 and DE027662
文摘Heterotopic ossification(HO)is a debilitating condition characterized by the pathologic formation of ectopic bone.HO occurs commonly following orthopedic surgeries,burns,and neurologic injuries.While surgical excision may provide palliation,the procedure is often burdened with significant intra-operative blood loss due to a more robust contribution of blood supply to the pathologic bone than to native bone.Based on these clinical observations,we set out to examine the role of vascular signaling in HO.Vascular endothelial growth factor A(VEGFA)has previously been shown to be a crucial pro-angiogenic and pro-osteogenic cue during normal bone development and homeostasis.Our findings,using a validated mouse model of HO,demonstrate that HO lesions are highly vascular,and that VEGFA is critical to ectopic bone formation,despite lacking a contribution of endothelial cells within the developing anlagen.
基金the National Natural Science Foundation of China(No.22138013).
文摘Heteroatom doping has emerged as a prevailing strategy to enhance the storage of sodium ions in carbon materials.However,the underlying mechanism governing the performance enhancement remains undisclosed.Herein,we fabricated N/S co-doped carbon beaded fibers(S-N-CBFs),which exhibited glorious rate performance and durableness in Na+storage,showcasing no obvious capacity decay even after 3500 cycles.Furthermore,when used as anodes in sodium-ion capacitors,the S-N-CBFs delivered exceptional results,boasting a high energy density of 225 Wh·kg^(-1),superior power output of 22500 W·kg^(-1),and outstanding cycling stability with a capacity attenuation of merely 0.014%per cycle after 4000 cycles at 2 A·g^(-1).Mechanistic investigations revealed that the incorporation of both pyridinic N and pyrrolic N into the carbon matrix of S-N-CBFs induced internal electric fields(IEFs),with the former IEF being stronger than the latter,in conjunction with the doped S atom.Density functional theory calculations further unveiled that the intensity of the IEF directly influenced the adsorption of Na+,thereby resulting in the exceptional performances of S-N-CBFs as sodium-ion storage materials.This work uncovers the pivotal role of IEF in regulating the electronic structure of carbon materials and enhancing their Na^(+)storage capabilities,providing valuable insights for the development of more advanced electrode materials.
基金Project supported by Fundamental Research Funds for the Central Universities of China(FRF-BR-20-03B)the National Key R&D Program of China(2017YFF0106006)。
文摘Strategical elements,such as rare earth elements,play a crucial role in the industry,especially in producing high-tech materials.Major global industries have developed a strong dependence on rare earth materials.Every year,there are innovations in industries such as modern technology,green energy,or communications technology,which need more strategic metals to improve investment profitability.This article reviews advances in rare earth separation methods and techniques to guide and recommend the best extractants,depending on leaching conditions and the final target product.Each method for separating and extracting agents is individually revised in terms of the mechanism and interaction of providing rare earth elements.This paper also evaluates past and current trends of these methods and technical extractants and identifies their strengths and weaknesses.