Recently, MAX phases show great potential in lithium-ion uptake due to their excellent electrical conductivity and unique lamellar-structure accommodating lithium ions. However, the reports about MAX electrodes for li...Recently, MAX phases show great potential in lithium-ion uptake due to their excellent electrical conductivity and unique lamellar-structure accommodating lithium ions. However, the reports about MAX electrodes for lithium-ion battery up to now are relatively low. Herein we report the preparation of surface oxygen-deficient Ti2SC with abundant oxygen vacancies by a facile surface engineering method. When using as a lithium storage anode, this oxygen-deficient Ti2SC delivers a high capacity of 350 m Ah/g at a current density of 400 m A/g as well as excellent rate performance, doubling the capacity compared to that of Ti2SC without oxygen vacancies. Confirmed by electrochemical impedance spectroscopy(EIS)and kinetic mechanism analyses, after reducing surface oxides and generation of oxygen vacancies, the as-received Ti2SC exhibits higher electrical conductivity and faster lithium ion diffusion. Thus this work offers a facial and effective strategy of optimizing the surface structure of MAX phases, further to achieve an enhanced lithium-ion uptake for lithium-ion batteries or capacitors.展开更多
Although multifarious tumor-targeting modifications of nanoparticulate systems have been attempted in joint efforts by our predecessors,it remains challenging for nanomedicine to traverse physiological barriers involv...Although multifarious tumor-targeting modifications of nanoparticulate systems have been attempted in joint efforts by our predecessors,it remains challenging for nanomedicine to traverse physiological barriers involving blood vessels,tissues,and cell barriers to thereafter demonstrate excellent antitumor effects.To further overcome these inherent obstacles,we designed and prepared mycoplasma membrane(MM)-fused liposomes(LPs)with the goal of employing circulating neutrophils with the advantage of inflammatory cytokine-guided autonomous tumor localization to transport nanoparticles.We also utilized in vivo neutrophil activation induced by the liposomal form of the immune activator resiquimod(LPsR848).Fused LPs preparations retained mycoplasma pathogen characteristics and achieved rapid recognition and endocytosis by activated neutrophils stimulated by LPs-R848.The enhanced neutrophil infiltration in homing of the inflammatory tumor microenvironment allowed more nanoparticles to be delivered into solid tumors.Facilitated by the formation of neutrophil extracellular traps(NETs),podophyllotoxin(POD)-loaded MM-fused LPs(MM-LPs-POD)were concomitantly released from neutrophils and subsequently engulfed by tumor cells during inflammation.MM-LPs-POD displayed superior suppression efficacy of tumor growth and lung metastasis in a 4T1 breast tumor model.Overall,such a strategy of pathogen-mimicking nanoparticles hijacking neutrophils in situ combined with enhanced neutrophil infiltration indeed elevates the potential of chemotherapeutics for tumor targeting therapy.展开更多
Ti3C2Tx,a most studied member of MXene family,shows promise as a candidate electrode for pseudocapacitor due to its electronic conductivity and hydrophilic surface.However,the unsatisfactory yield of Ti3C2Tx few-layer...Ti3C2Tx,a most studied member of MXene family,shows promise as a candidate electrode for pseudocapacitor due to its electronic conductivity and hydrophilic surface.However,the unsatisfactory yield of Ti3C2Tx few-layer flakes significantly restricted it in real applications.Here,we proposed a simple solution to boost the yield of Ti3C2Tx few-layer flakes by decreasing precursor size.When using the small500 mesh Ti3AlC2 powders as raw material,high yield of 65%was successfully achieved.Moreover,the asreceived small flakes also exhibit an enhanced pseudocapacior performance owing to their excellent electrical conductivity,expanded inte rlayer space and more O content on the surface.This work not only sheds light on the cost effective mass production of Ti3C2Tx few-layer flakes,but also provides an efficient solution for the design of MXene electrodes with high pseudocapacior performance.展开更多
As a promising material for the new generation of high-speed railway contact wires,the comprehensive optimization of the electrical conductivity,strength,hardness and wear resistance of the Cu-Cr-Zr alloy has received...As a promising material for the new generation of high-speed railway contact wires,the comprehensive optimization of the electrical conductivity,strength,hardness and wear resistance of the Cu-Cr-Zr alloy has received extensive attention.In this paper,a high-performance Cu-1Cr-0.1Zr alloy with an ultimate tensile strength of 599.1 MPa,a uniform elongation of 8.6%,a microhardness of 195.7 HV_(0.2) and an electrical conductivity of 80.07%IACS was achieved by the continuous extrusion forming(CEF)and subsequent peak-aging treatment.The grain refinement strengthening,dislocation strengthening and precipitation strengthening are identified to be responsible for the excellent electrical and mechanical properties of Cu-Cr-Zr alloy.The wear behavior of Cu-Cr-Zr alloy was investigated by examining the evolution of worn surface morphology and subsurface microstructure.The microhardness(H)and reduced elastic modulus(E_(r))of the subsurface below the worn surface measured by nanoindentation were calculated to gage the tribological performance of Cu-Cr-Zr alloy.Results show that the continuously extruded and subsequently peak-aged specimen has the best wear resistance,which indicates that the tribological properties of CuCr-Zr alloy strongly depend on its strength and hardness.It can be concluded that the CEF and subsequent aging treatment process provides a new and high-efficiency procedure for the continuous preparation of Cu-Cr-Zr alloys.展开更多
基金supported by the National Natural Science Foundation of China (Nos. 21671167 and 51602277)Qinglan Project of Jiangsu Province。
文摘Recently, MAX phases show great potential in lithium-ion uptake due to their excellent electrical conductivity and unique lamellar-structure accommodating lithium ions. However, the reports about MAX electrodes for lithium-ion battery up to now are relatively low. Herein we report the preparation of surface oxygen-deficient Ti2SC with abundant oxygen vacancies by a facile surface engineering method. When using as a lithium storage anode, this oxygen-deficient Ti2SC delivers a high capacity of 350 m Ah/g at a current density of 400 m A/g as well as excellent rate performance, doubling the capacity compared to that of Ti2SC without oxygen vacancies. Confirmed by electrochemical impedance spectroscopy(EIS)and kinetic mechanism analyses, after reducing surface oxides and generation of oxygen vacancies, the as-received Ti2SC exhibits higher electrical conductivity and faster lithium ion diffusion. Thus this work offers a facial and effective strategy of optimizing the surface structure of MAX phases, further to achieve an enhanced lithium-ion uptake for lithium-ion batteries or capacitors.
基金supported by the National Natural Science Foundation of China(81872986)the"Double First-Class"University project(CPU2018GF03,China)+2 种基金the 111 Project from the Ministry of Education of Chinathe State Administration of Foreign Export Affairs of China(B18056)the Drug Innovation Major Project(2018ZX09711-001-007,2018ZX09735002-003,China)。
文摘Although multifarious tumor-targeting modifications of nanoparticulate systems have been attempted in joint efforts by our predecessors,it remains challenging for nanomedicine to traverse physiological barriers involving blood vessels,tissues,and cell barriers to thereafter demonstrate excellent antitumor effects.To further overcome these inherent obstacles,we designed and prepared mycoplasma membrane(MM)-fused liposomes(LPs)with the goal of employing circulating neutrophils with the advantage of inflammatory cytokine-guided autonomous tumor localization to transport nanoparticles.We also utilized in vivo neutrophil activation induced by the liposomal form of the immune activator resiquimod(LPsR848).Fused LPs preparations retained mycoplasma pathogen characteristics and achieved rapid recognition and endocytosis by activated neutrophils stimulated by LPs-R848.The enhanced neutrophil infiltration in homing of the inflammatory tumor microenvironment allowed more nanoparticles to be delivered into solid tumors.Facilitated by the formation of neutrophil extracellular traps(NETs),podophyllotoxin(POD)-loaded MM-fused LPs(MM-LPs-POD)were concomitantly released from neutrophils and subsequently engulfed by tumor cells during inflammation.MM-LPs-POD displayed superior suppression efficacy of tumor growth and lung metastasis in a 4T1 breast tumor model.Overall,such a strategy of pathogen-mimicking nanoparticles hijacking neutrophils in situ combined with enhanced neutrophil infiltration indeed elevates the potential of chemotherapeutics for tumor targeting therapy.
基金the National Natural Science Foundation of China(No.21671167)the Joint Open Fund of Jiangsu Collaborative Innovation Center for Ecological Building Material and Environmental Protection Equipments and Key Laboratory for Advanced Technology in Environmental Protection of Jiangsu Province(No.JH201847)the National Natural Science Foundation of China(No.51602277)。
文摘Ti3C2Tx,a most studied member of MXene family,shows promise as a candidate electrode for pseudocapacitor due to its electronic conductivity and hydrophilic surface.However,the unsatisfactory yield of Ti3C2Tx few-layer flakes significantly restricted it in real applications.Here,we proposed a simple solution to boost the yield of Ti3C2Tx few-layer flakes by decreasing precursor size.When using the small500 mesh Ti3AlC2 powders as raw material,high yield of 65%was successfully achieved.Moreover,the asreceived small flakes also exhibit an enhanced pseudocapacior performance owing to their excellent electrical conductivity,expanded inte rlayer space and more O content on the surface.This work not only sheds light on the cost effective mass production of Ti3C2Tx few-layer flakes,but also provides an efficient solution for the design of MXene electrodes with high pseudocapacior performance.
基金financially supported by the National Key Research and Development Program of China(No.2016YFB0301401)the National Natural Science Foundation of China(Nos.U1860202,U1732276,50134010,51904184 and 52004156)the Science and Technology Commission of Shanghai Municipality(Nos.13JC14025000 and 15520711000)。
文摘As a promising material for the new generation of high-speed railway contact wires,the comprehensive optimization of the electrical conductivity,strength,hardness and wear resistance of the Cu-Cr-Zr alloy has received extensive attention.In this paper,a high-performance Cu-1Cr-0.1Zr alloy with an ultimate tensile strength of 599.1 MPa,a uniform elongation of 8.6%,a microhardness of 195.7 HV_(0.2) and an electrical conductivity of 80.07%IACS was achieved by the continuous extrusion forming(CEF)and subsequent peak-aging treatment.The grain refinement strengthening,dislocation strengthening and precipitation strengthening are identified to be responsible for the excellent electrical and mechanical properties of Cu-Cr-Zr alloy.The wear behavior of Cu-Cr-Zr alloy was investigated by examining the evolution of worn surface morphology and subsurface microstructure.The microhardness(H)and reduced elastic modulus(E_(r))of the subsurface below the worn surface measured by nanoindentation were calculated to gage the tribological performance of Cu-Cr-Zr alloy.Results show that the continuously extruded and subsequently peak-aged specimen has the best wear resistance,which indicates that the tribological properties of CuCr-Zr alloy strongly depend on its strength and hardness.It can be concluded that the CEF and subsequent aging treatment process provides a new and high-efficiency procedure for the continuous preparation of Cu-Cr-Zr alloys.
