Na-ion batteries(NIBs)have attracted considerable attention in recent years owing to the high abundance and low cost of Na.It is well known that S doping can improve the electrochemical performance of carbon materials...Na-ion batteries(NIBs)have attracted considerable attention in recent years owing to the high abundance and low cost of Na.It is well known that S doping can improve the electrochemical performance of carbon materials for NIBs.However,the current methods for S doping in carbons normally involve toxic precursors or rigorous conditions.In this work,we report a creative and facile strategy for preparing S-doped porous carbons(SCs)via the pyrolysis of conjugated microporous polymers(CMPs).Briefly,thiophene-based CMPs served as the precursors and doping sources simultaneously.Simple direct carbonization of CMPs produced S-doped carbon materials with highly porous structures.When used as an anode for NIBs,the SCs exhibited a high reversible capacity of 440 mAh g?1 at 50 mA g?1 after 100 cycles,superior rate capability,and excellent cycling stability(297 mAh g?1 after 1000 cycles at 500 mA g?1),outperforming most S-doped carbon materials reported thus far.The excellent performance of the SCs is attributed to the expanded lattice distance after S doping.Furthermore,we employed ex situ X-ray photoelectron spectroscopy to investigate the electrochemical reaction mechanism of the SCs during sodiation-desodiation,which can highlight the role of doped S for Na-ion storage.展开更多
The dry powder inhalation of antibiotics for the treatment of lung infections has attracted drastically increasing attention as it offers rapid local therapy at lower doses and minimal side effects.In this study,aztre...The dry powder inhalation of antibiotics for the treatment of lung infections has attracted drastically increasing attention as it offers rapid local therapy at lower doses and minimal side effects.In this study,aztreonam(AZT)was used as the model antibiotic and spraydried to prepare powders for inhalation.Amino acids of glycine(GLY),histidine(HIS)and leucine(LEU)were used as excipients to modify the spray-dried particles.It was demonstrated that the GLY-AZT spray-dried powders formed huge agglomerates with the size of 144.51μm,which made it very difficult to be delivered to the lungs(FPF:0.29%w/w only).In comparison with the AZT spray-dried powders,HIS-modified spray-dried powders showed increased compressibility,indicating larger distance and less cohesion between particles;while the LEU-modified spray-dried particles showed a hollow structure with significantly decreased densities.The fine particle fraction for HIS-and LEU-modified powders was 51.4%w/w and 61.7%w/w,respectively,and both were significantly increased(one-way ANOVA,Duncan’s test,P<0.05)compared to that of AZT spray-dried powders(45.4%w/w),showing a great potential to be applied in clinic.展开更多
Exploring the unusual orbital hybridization types of atoms and their new connection modes contributes to the development of chemical bond theory and can inspire compounds with unique molecular configurations.Dicoordin...Exploring the unusual orbital hybridization types of atoms and their new connection modes contributes to the development of chemical bond theory and can inspire compounds with unique molecular configurations.Dicoordinated sulfur(S)atoms(or anions)with sp3 hybridization in a bent-bridging mode are commonly observed in many inorganic and organic compounds.However,sp-hybridized S species have,thus far,been extremely rare,and the linearly bridging mode has only been“forcibly”achieved with the aid of metal–S multiple bonds and/or significant steric hindrance from the surrounding organic ligands.展开更多
基金Financial support from National Natural Science Foundation of China(Nos.51702056 and 51772135)the Ministry of Education of China(6141A02022516)China Postdoctoral Science Foundation(2017M622902 and 2019T120790).
文摘Na-ion batteries(NIBs)have attracted considerable attention in recent years owing to the high abundance and low cost of Na.It is well known that S doping can improve the electrochemical performance of carbon materials for NIBs.However,the current methods for S doping in carbons normally involve toxic precursors or rigorous conditions.In this work,we report a creative and facile strategy for preparing S-doped porous carbons(SCs)via the pyrolysis of conjugated microporous polymers(CMPs).Briefly,thiophene-based CMPs served as the precursors and doping sources simultaneously.Simple direct carbonization of CMPs produced S-doped carbon materials with highly porous structures.When used as an anode for NIBs,the SCs exhibited a high reversible capacity of 440 mAh g?1 at 50 mA g?1 after 100 cycles,superior rate capability,and excellent cycling stability(297 mAh g?1 after 1000 cycles at 500 mA g?1),outperforming most S-doped carbon materials reported thus far.The excellent performance of the SCs is attributed to the expanded lattice distance after S doping.Furthermore,we employed ex situ X-ray photoelectron spectroscopy to investigate the electrochemical reaction mechanism of the SCs during sodiation-desodiation,which can highlight the role of doped S for Na-ion storage.
基金support from Natural Science Foundation of Jiangsu Province(BK2011295)Youth Fund of Soochow University(SDY2011A21)。
文摘The dry powder inhalation of antibiotics for the treatment of lung infections has attracted drastically increasing attention as it offers rapid local therapy at lower doses and minimal side effects.In this study,aztreonam(AZT)was used as the model antibiotic and spraydried to prepare powders for inhalation.Amino acids of glycine(GLY),histidine(HIS)and leucine(LEU)were used as excipients to modify the spray-dried particles.It was demonstrated that the GLY-AZT spray-dried powders formed huge agglomerates with the size of 144.51μm,which made it very difficult to be delivered to the lungs(FPF:0.29%w/w only).In comparison with the AZT spray-dried powders,HIS-modified spray-dried powders showed increased compressibility,indicating larger distance and less cohesion between particles;while the LEU-modified spray-dried particles showed a hollow structure with significantly decreased densities.The fine particle fraction for HIS-and LEU-modified powders was 51.4%w/w and 61.7%w/w,respectively,and both were significantly increased(one-way ANOVA,Duncan’s test,P<0.05)compared to that of AZT spray-dried powders(45.4%w/w),showing a great potential to be applied in clinic.
基金support from the National Natural Science Foundation of China(nos.21671142,21875150,and 21720102006)the 111 Project(no.D20015)+2 种基金the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)Shanxi Natural Science Foundation(no.201901D111018)the OIT program of Shanxi Higher Education Institutions.
文摘Exploring the unusual orbital hybridization types of atoms and their new connection modes contributes to the development of chemical bond theory and can inspire compounds with unique molecular configurations.Dicoordinated sulfur(S)atoms(or anions)with sp3 hybridization in a bent-bridging mode are commonly observed in many inorganic and organic compounds.However,sp-hybridized S species have,thus far,been extremely rare,and the linearly bridging mode has only been“forcibly”achieved with the aid of metal–S multiple bonds and/or significant steric hindrance from the surrounding organic ligands.
