Fe-N compounds with excellent electrocatalytic oxygen reduction activity are considered to be one of the most promising non-precious metal materials for fuel cells.Fe-N compounds with excellent electrocatalytic oxygen...Fe-N compounds with excellent electrocatalytic oxygen reduction activity are considered to be one of the most promising non-precious metal materials for fuel cells.Fe-N compounds with excellent electrocatalytic oxygen reduction activity are considered to be one of the most promising non-precious metal materials for fuel cells,which focuses on the Fe-N4 single-atom catalysts and the iron nitride materials(such as Fe2N and Fe3N).A hybridized catalyst having a hierarchical porous structure with regular macropores could enable the desired mass transfer efficiency in the catalytic process.In this study,we have constructed a new type of hybrid catalyst having iron and iron-nitrogen alloy nanoparticles(Fe-N austenite,termed as Fe-NA)embedded in the three-dimensional ordered macroporous N-doped carbon(3DOM Fe/Fe-NA@NC)by direct pyrolysis of single-source dicyandiamide-based iron metal-organic frameworks.The as-synthesized composites preserve the hierarchical porous carbon framework with ordered macropores and high specific surface area,incorporating the uniformly dispersed iron/iron-nitrogen austenite nanoparticles.Thereby,the striking architectural configuration embedded with highly active catalytic species delivers a superior oxygen reduction activity with a half-wave potential of 0.88 V and a subsequent superior Zn-air battery performance with high open-circuit voltage and continuous stability as compared to those using a commercial 20%Pt/C catalyst.展开更多
This vertically self‐pillared(VSP)structure extends the application range of traditional porous materials with facile mass/ion transport and enhanced reaction kinetics.Here,we prepare a single crystal metal‐organic ...This vertically self‐pillared(VSP)structure extends the application range of traditional porous materials with facile mass/ion transport and enhanced reaction kinetics.Here,we prepare a single crystal metal‐organic framework(MOF),employing the ZIF‐67 structure as a proof of concept,which is constructed by vertically self‐pillared nanosheets(VSP‐MOF).We further converted VSP‐MOF into VSP‐cobalt sulfide(VSP‐CoS2)through a sulfidation process.Catalysis plays an important role in almost all battery technologies;for metallic batteries,lithium anodes exhibit a high theoretical specific capacity,low density,and low redox potential.However,during the half‐cell reaction(Li++e=Li),uncontrolled dendritic Li penetrates the separator and solid electrolyte interphase layer.When employed as a composite scaffold for lithium metal deposition,there are many advantage to using this framework:1)the VSP‐CoS2 substrate provides a high specific surface area to dissipate the ion flux and mass transfer and acts as a pre‐catalyst,2)the catalytic Co center favors the charge transfer process and preferentially binds the Li+with the enhanced electrical fields,and 3)the VSP structure guides the metallic propagation along the nanosheet 2D orientation without the protrusive dendrites.All these features enable the VSP structure in metallic batteries with encouraging performances.展开更多
Objective： Interphalangeal joint con- tracture is a challenging complication of hand trauma, which reduces the functional capacity of the entire hand. In this study we evaluated the results of soft tissue distraction...Objective： Interphalangeal joint con- tracture is a challenging complication of hand trauma, which reduces the functional capacity of the entire hand. In this study we evaluated the results of soft tissue distraction with no collateral ligament transection or volar plate removal in comparison with traditional operation of contracture re- lease and partial ligament transection and volar plate removal. Methods： In this prospective study, a total of 40 pa- tients in two equal groups （A and B） were studied. Patients suffering from chronic flexion contracture of abrasive trau- matic nature were included. Group A were treated by soft tissue distraction using pentagonal frame technique and in Group B the contracture release was followed by finger splinting. Results： Analyzed data revealed a significant differ- ence between the two groups for range of motion in the proximal interphalangeal joints （P〈0.05）, while it was not meaningful in the distal interphalangeal joints （P〉0.05）. There was not a significant difference in the degrees of flexion contracture between groups （P〉0.05）. Regression analysis showed that using pentagonal frame technique significantly increased the mean improvement in range of motion of proxi- mal interphalangeal joints （P〈0.001）, while the higher the preoperative flexion contracture was observed in proximal interphalangeal joints, the lower improvement was achieved in range of motion of proximal interphalangeal joints after intervention （P〈0.001）. Conclusion： Soft tissue distraction using pentagonal frame technique with gradual and continuous collateral liga- ment and surrounding joint tissues distraction combined with skin Z-plasty significantly improves the range of mo- tion in patients with chronic traumatic flexion deformity of proximal and/or distal interphalangeal joints.展开更多
文摘Fe-N compounds with excellent electrocatalytic oxygen reduction activity are considered to be one of the most promising non-precious metal materials for fuel cells.Fe-N compounds with excellent electrocatalytic oxygen reduction activity are considered to be one of the most promising non-precious metal materials for fuel cells,which focuses on the Fe-N4 single-atom catalysts and the iron nitride materials(such as Fe2N and Fe3N).A hybridized catalyst having a hierarchical porous structure with regular macropores could enable the desired mass transfer efficiency in the catalytic process.In this study,we have constructed a new type of hybrid catalyst having iron and iron-nitrogen alloy nanoparticles(Fe-N austenite,termed as Fe-NA)embedded in the three-dimensional ordered macroporous N-doped carbon(3DOM Fe/Fe-NA@NC)by direct pyrolysis of single-source dicyandiamide-based iron metal-organic frameworks.The as-synthesized composites preserve the hierarchical porous carbon framework with ordered macropores and high specific surface area,incorporating the uniformly dispersed iron/iron-nitrogen austenite nanoparticles.Thereby,the striking architectural configuration embedded with highly active catalytic species delivers a superior oxygen reduction activity with a half-wave potential of 0.88 V and a subsequent superior Zn-air battery performance with high open-circuit voltage and continuous stability as compared to those using a commercial 20%Pt/C catalyst.
文摘This vertically self‐pillared(VSP)structure extends the application range of traditional porous materials with facile mass/ion transport and enhanced reaction kinetics.Here,we prepare a single crystal metal‐organic framework(MOF),employing the ZIF‐67 structure as a proof of concept,which is constructed by vertically self‐pillared nanosheets(VSP‐MOF).We further converted VSP‐MOF into VSP‐cobalt sulfide(VSP‐CoS2)through a sulfidation process.Catalysis plays an important role in almost all battery technologies;for metallic batteries,lithium anodes exhibit a high theoretical specific capacity,low density,and low redox potential.However,during the half‐cell reaction(Li++e=Li),uncontrolled dendritic Li penetrates the separator and solid electrolyte interphase layer.When employed as a composite scaffold for lithium metal deposition,there are many advantage to using this framework:1)the VSP‐CoS2 substrate provides a high specific surface area to dissipate the ion flux and mass transfer and acts as a pre‐catalyst,2)the catalytic Co center favors the charge transfer process and preferentially binds the Li+with the enhanced electrical fields,and 3)the VSP structure guides the metallic propagation along the nanosheet 2D orientation without the protrusive dendrites.All these features enable the VSP structure in metallic batteries with encouraging performances.
文摘Objective： Interphalangeal joint con- tracture is a challenging complication of hand trauma, which reduces the functional capacity of the entire hand. In this study we evaluated the results of soft tissue distraction with no collateral ligament transection or volar plate removal in comparison with traditional operation of contracture re- lease and partial ligament transection and volar plate removal. Methods： In this prospective study, a total of 40 pa- tients in two equal groups （A and B） were studied. Patients suffering from chronic flexion contracture of abrasive trau- matic nature were included. Group A were treated by soft tissue distraction using pentagonal frame technique and in Group B the contracture release was followed by finger splinting. Results： Analyzed data revealed a significant differ- ence between the two groups for range of motion in the proximal interphalangeal joints （P〈0.05）, while it was not meaningful in the distal interphalangeal joints （P〉0.05）. There was not a significant difference in the degrees of flexion contracture between groups （P〉0.05）. Regression analysis showed that using pentagonal frame technique significantly increased the mean improvement in range of motion of proxi- mal interphalangeal joints （P〈0.001）, while the higher the preoperative flexion contracture was observed in proximal interphalangeal joints, the lower improvement was achieved in range of motion of proximal interphalangeal joints after intervention （P〈0.001）. Conclusion： Soft tissue distraction using pentagonal frame technique with gradual and continuous collateral liga- ment and surrounding joint tissues distraction combined with skin Z-plasty significantly improves the range of mo- tion in patients with chronic traumatic flexion deformity of proximal and/or distal interphalangeal joints.
