The author proves that the isoperimetric inequality on the graphic curves over circle or hyperplanes over S^(n-1) is satisfied in the cigar steady soliton and in the Bryant steady soliton.Since both of them are Rieman...The author proves that the isoperimetric inequality on the graphic curves over circle or hyperplanes over S^(n-1) is satisfied in the cigar steady soliton and in the Bryant steady soliton.Since both of them are Riemannian manifolds with warped product metric,the author utilize the result of Guan-Li-Wang to get his conclusion.For the sake of the soliton structure,the author believes that the geometric restrictions for manifolds in which the isoperimetric inequality holds are naturally satisfied for steady Ricci solitons.展开更多
The trace amount of CO in H2-rich gas poisons Pt electrode when it is adopted as feedstock for proton-exchange-membrane fuel cells.Preferential oxidation of CO(PROX)is a promising approach to selectively oxidize the t...The trace amount of CO in H2-rich gas poisons Pt electrode when it is adopted as feedstock for proton-exchange-membrane fuel cells.Preferential oxidation of CO(PROX)is a promising approach to selectively oxidize the trace amount of CO while keeping H2 unoxidized.Catalyst plays important roles in PROX.To date,enormous catalysts have been developed for PROX.Summarizing the catalysts developed for PROX and unveiling the reaction mechanism could definitely advance this research field.Herein,in this review,according to the nature of the active sites on the catalysts,we classify the catalysts into group VIII metal-based catalyst,group IB metal-based catalysts,group VIII-group IB bimetallic catalysts,transitional metal oxide catalysts as well as others,describe the progress of the catalysts in PROX in the latest five years,and extract the underlying reaction mechanism,with the aim to provide guidance for the rational design of efficient catalysts in the future.展开更多
Fluorescent polymer dots(Pdots)have the advantages of excellent optical properties,great biocompatibility and high photostability.Herein,we feed ultra-low doses Pdots to silkworms for the first time and aim to prepare...Fluorescent polymer dots(Pdots)have the advantages of excellent optical properties,great biocompatibility and high photostability.Herein,we feed ultra-low doses Pdots to silkworms for the first time and aim to prepare dual-performance modified silks.After Pdots feeding,the fluorescence signal of cocoons and degummed silks increases significantly,which is more stable and more uniform than that of post-treatment silks.Moreover,Pdots hinder the conformation transformation of silk fibroin and improve the mechanical property of twisted silk strand.The highest elongation at break point is 20.75±0.03% and breaking strength is 271.7±3.8 MPa.With excellent fluorescence and mechanical properties,the optimized silks are successfully applied as a scaffold for cell culture and imaging.Furthermore,we investigate the metabolism of Pdots in the silkworms for understanding the behaviours of Pdots in the process of silks synthesis and secretion.展开更多
基金This work was supported by the National Natural Science Foundation of China(Nos.11721101,11526212).
文摘The author proves that the isoperimetric inequality on the graphic curves over circle or hyperplanes over S^(n-1) is satisfied in the cigar steady soliton and in the Bryant steady soliton.Since both of them are Riemannian manifolds with warped product metric,the author utilize the result of Guan-Li-Wang to get his conclusion.For the sake of the soliton structure,the author believes that the geometric restrictions for manifolds in which the isoperimetric inequality holds are naturally satisfied for steady Ricci solitons.
基金support from the National Natural Science Foundation of China(No.21902116)the Scientific Research Foundation of Liaoning province of China(No.JQL202015403).
文摘The trace amount of CO in H2-rich gas poisons Pt electrode when it is adopted as feedstock for proton-exchange-membrane fuel cells.Preferential oxidation of CO(PROX)is a promising approach to selectively oxidize the trace amount of CO while keeping H2 unoxidized.Catalyst plays important roles in PROX.To date,enormous catalysts have been developed for PROX.Summarizing the catalysts developed for PROX and unveiling the reaction mechanism could definitely advance this research field.Herein,in this review,according to the nature of the active sites on the catalysts,we classify the catalysts into group VIII metal-based catalyst,group IB metal-based catalysts,group VIII-group IB bimetallic catalysts,transitional metal oxide catalysts as well as others,describe the progress of the catalysts in PROX in the latest five years,and extract the underlying reaction mechanism,with the aim to provide guidance for the rational design of efficient catalysts in the future.
基金This study was supported by Grants from the National Natural Science Foundation of China(81974273,81671738,81301261 and 21374059)the National Key R&D Program of China(2016YFC1303100)the Shanghai Pujiang Project(13PJ1405000).
文摘Fluorescent polymer dots(Pdots)have the advantages of excellent optical properties,great biocompatibility and high photostability.Herein,we feed ultra-low doses Pdots to silkworms for the first time and aim to prepare dual-performance modified silks.After Pdots feeding,the fluorescence signal of cocoons and degummed silks increases significantly,which is more stable and more uniform than that of post-treatment silks.Moreover,Pdots hinder the conformation transformation of silk fibroin and improve the mechanical property of twisted silk strand.The highest elongation at break point is 20.75±0.03% and breaking strength is 271.7±3.8 MPa.With excellent fluorescence and mechanical properties,the optimized silks are successfully applied as a scaffold for cell culture and imaging.Furthermore,we investigate the metabolism of Pdots in the silkworms for understanding the behaviours of Pdots in the process of silks synthesis and secretion.
