Designing single-atom catalysts for oxygen reduction reaction(ORR)are fashionable but challenging to boost the zinc-air battery performance.Significantly enhanced ORR activity by manganese(Mn)singleatom catalysts can ...Designing single-atom catalysts for oxygen reduction reaction(ORR)are fashionable but challenging to boost the zinc-air battery performance.Significantly enhanced ORR activity by manganese(Mn)singleatom catalysts can be achieved by accurately regulating the coordination number of isolated Mn atoms.Theoretical calculations indicate that the single Mn-N5sites possess lower free energy barrier and higher oxygen adsorption performance than single Mn-N4sites to accelerate the ORR kinetics.Target to it,here we synthesize an atomically dispersed Mn-N5catalyst by precisely axial coordination of pyridinic-N doped into two-dimensional(2D)porous nanocarbon sheets(~3.56 nm thickness),which reveals outstanding catalytic activity and ultrahigh stability for the ORR in zinc-air battery owing to the inhomogeneous charge distribution of Mn-N5sites compared to the conventional single-site Mn-N4catalyst and Pt/C.This work gives a new strategy for in situ regulating the electronic structure of metal single-atoms and further promoting the overall ORR performance in energy systems.展开更多
Muscle groups perform their functions in the human body via bilateral muscle actuation,which brings bionic inspiration to artificial robot design.Building soft robotic systems with artificial muscles and multiple cont...Muscle groups perform their functions in the human body via bilateral muscle actuation,which brings bionic inspiration to artificial robot design.Building soft robotic systems with artificial muscles and multiple control dimensions could be an effective means to develop highly controllable soft robots.Here,we report a bilateral actuator with a bilateral deformation function similar to that of a muscle group that can be used for soft robots.To construct this bilateral actuator,a low-cost VHB 4910 dielectric elastomer was selected as the artificial muscle,and polymer films manufactured with specific shapes served as the actuator frame.By end-to-end connecting these bilateral actuators,a gear-shaped 3D soft robot with diverse motion capabilities could be developed,benefiting from adjustable actuation combinations.Lying on the ground with all feet on the ground,a crawling soft robot with dexterous movement along multiple directions was realized.Moreover,the directional steering was instantaneous and efficient.With two feet standing on the ground,it also acted as a rolling soft robot that can achieve bidirectional rolling motion and climbing motion on a 2°slope.Finally,inspired by the orbicularis oris muscle in the mouth,a mouthlike soft robot that could bite and grab objects 5.3 times of its body weight was demonstrated.The bidirectional function of a single actuator and the various combination modes among multiple actuators together allow the soft robots to exhibit diverse functionalities and flexibility,which provides a very valuable reference for the design of highly controllable soft robots.展开更多
The as-extruded Mg-10Al_(2)Y master alloy was chosen as a novel grain refiner for as-cast Mg-3Y alloy.Contrast samples of cast Mg-3Y alloy added with pure Al and Mg-Zr master alloy grain refiners were prepared under t...The as-extruded Mg-10Al_(2)Y master alloy was chosen as a novel grain refiner for as-cast Mg-3Y alloy.Contrast samples of cast Mg-3Y alloy added with pure Al and Mg-Zr master alloy grain refiners were prepared under the same conditions.In this study,the influence of addition amounts of Al_(2)Y and holding time on grain refinement efficiency as well as tensile properties was investigated.And the grain refining ability of the Al_(2)Y particles was systematically evaluated in terms of the addition amounts,number density of the Al_(2)Y particles and holding time.The finest grains are achieved at 2 wt% Al_(2)Y addition amount,which corresponds to number density of the polygonal Al_(2)Y particles of 420-460 mm^(-2).The Mg-10Al_(2)Y master alloy has significant refinement performance and no refining recession occurs at the holding time within 60 min,or the settling time up to 180 min.Grain refinement and the second phase strengthening of uniformly distributed Al_(2)Y particles contribute to the simultaneous enhancement on both strength and elongation of Mg-3Y alloy.展开更多
Long-emission carbon dots(CDs) is triggering immense enthusiasm on account of their intrinsic merits of high chemical stability and excellent optical properties.In this study,a facile and rapid approach was developed ...Long-emission carbon dots(CDs) is triggering immense enthusiasm on account of their intrinsic merits of high chemical stability and excellent optical properties.In this study,a facile and rapid approach was developed for the preparation of barium-doped carbon dots(Ba-CDs) with yellow fluo rescence emission and high quantum yields.Surface chemistry and the chemical architecture of the Ba-CDs was revealed under various spectroscopic methods.This work provides more insights into the effects of charge transfer caused by Ba heteroatoms,which is considered as the most challenging step in the investigation on luminescence mechanism.Remarkably,the prepared Ba-CDs were successfully applied as fluorescent probes in the detection of trace water in organic solvents(ethanol,isopropanol,acetone,tetrahydrofuran).Comparing with traditional fluorescent probes for water detection in organic solvents,Ba-CDs detection provides a more sensitive,much faster and more economical approach.展开更多
Origami has become an optimal methodological choice for creating complex three-dimensional(3D)structures and soft robots.The simple and low-cost origami-inspired folding assembly provides a new method for developing 3...Origami has become an optimal methodological choice for creating complex three-dimensional(3D)structures and soft robots.The simple and low-cost origami-inspired folding assembly provides a new method for developing 3D soft robots,which is ideal for future intelligent robotic systems.Here,we present a series of materials,structural designs,and fabrication methods for developing independent,electrically controlled origami 3D soft robots for walking and soft manipulators.The 3D soft robots are based on soft actuators,which are multilayer structures with a dielectric elastomer(DE)film as the deformation layer and a laser-cut PET film as the supporting flexible frame.The triangular and rectangular design of the soft actuators allows them to be easily assembled into crawling soft robots and pyramidal-and square-shaped 3D structures.The crawling robot exhibits very stable crawling behaviors and can carry loads while walking.Inspired by origami folding,the pyramidal and square-shaped 3D soft robots exhibit programmable out-of-plane deformations and easy switching between two-dimensional(2D)and 3D structures.The electrically controllable origami deformation allows the 3D soft robots to be used as soft manipulators for grasping and precisely locking 3D objects.This work proves that origami-inspired fold-based assembly of DE actuators is a good reference for the development of soft actuators and future intelligent multifunctional soft robots.展开更多
基金supported by the National Natural Science Foundation of China(22275026 and 21805024)the Natural Science Foundation of Chongqing,China(cstc2021jcyj-msxm X0783,cstc2019jscx-msxm X0393 and cstc2018jcyj AX0461)+1 种基金the Scientific and Technological Research Program of Chongqing Municipal Education Commission(KJZD-K202101303,KJQN201901335 and KJQN202001322)the Scientific Research Program of Chongqing Urban Administration(CGKZ2020-26)。
文摘Designing single-atom catalysts for oxygen reduction reaction(ORR)are fashionable but challenging to boost the zinc-air battery performance.Significantly enhanced ORR activity by manganese(Mn)singleatom catalysts can be achieved by accurately regulating the coordination number of isolated Mn atoms.Theoretical calculations indicate that the single Mn-N5sites possess lower free energy barrier and higher oxygen adsorption performance than single Mn-N4sites to accelerate the ORR kinetics.Target to it,here we synthesize an atomically dispersed Mn-N5catalyst by precisely axial coordination of pyridinic-N doped into two-dimensional(2D)porous nanocarbon sheets(~3.56 nm thickness),which reveals outstanding catalytic activity and ultrahigh stability for the ORR in zinc-air battery owing to the inhomogeneous charge distribution of Mn-N5sites compared to the conventional single-site Mn-N4catalyst and Pt/C.This work gives a new strategy for in situ regulating the electronic structure of metal single-atoms and further promoting the overall ORR performance in energy systems.
基金supported by the National Science Foundation of China(U21A20492,Grant Nos.62171069,62275041,and 62122002)the National Key R&D Program of China(Grant No.2018YFB0407102)+5 种基金the Sichuan Science and Technology Program(Grant Nos.2022YFH0081,2022YFG0012,and 2022YFG0013)the Open Project of Sichuan Provincial Key Laboratory of display science and technology(ZYGX2022K018)the Program of Chongqing Science&Technology Commission(cstc2019jcyj-msxmX0877,cstc2019jscxfxydX0048,and cstc2019jcyjjqX0021)Cooperation projects between universities at Chongqing and institutes affiliated to the Chinese Academy of Sciences(HZ2021019)the Scientific and Technological Research Program of Chongqing Municipal Education Commission(KJZD-K201901302,KJQN201901348,and KJCX2020048)the City University of Hong Kong(Grant Nos.9667221 and 9680322).
文摘Muscle groups perform their functions in the human body via bilateral muscle actuation,which brings bionic inspiration to artificial robot design.Building soft robotic systems with artificial muscles and multiple control dimensions could be an effective means to develop highly controllable soft robots.Here,we report a bilateral actuator with a bilateral deformation function similar to that of a muscle group that can be used for soft robots.To construct this bilateral actuator,a low-cost VHB 4910 dielectric elastomer was selected as the artificial muscle,and polymer films manufactured with specific shapes served as the actuator frame.By end-to-end connecting these bilateral actuators,a gear-shaped 3D soft robot with diverse motion capabilities could be developed,benefiting from adjustable actuation combinations.Lying on the ground with all feet on the ground,a crawling soft robot with dexterous movement along multiple directions was realized.Moreover,the directional steering was instantaneous and efficient.With two feet standing on the ground,it also acted as a rolling soft robot that can achieve bidirectional rolling motion and climbing motion on a 2°slope.Finally,inspired by the orbicularis oris muscle in the mouth,a mouthlike soft robot that could bite and grab objects 5.3 times of its body weight was demonstrated.The bidirectional function of a single actuator and the various combination modes among multiple actuators together allow the soft robots to exhibit diverse functionalities and flexibility,which provides a very valuable reference for the design of highly controllable soft robots.
基金Project supported by the Chongqing Science and Technology Commission(cstc2017zdcy-zdzxX0006,cstc2018jcyjAX0472,cstc2018jcyjAX0339)Science and Technology Research Program of Chongqing Municipal Education Commission(KJQN201801306,KJ1711290)Chongqing University of Arts and Sciences(501100002867)(P2017XC08)。
文摘The as-extruded Mg-10Al_(2)Y master alloy was chosen as a novel grain refiner for as-cast Mg-3Y alloy.Contrast samples of cast Mg-3Y alloy added with pure Al and Mg-Zr master alloy grain refiners were prepared under the same conditions.In this study,the influence of addition amounts of Al_(2)Y and holding time on grain refinement efficiency as well as tensile properties was investigated.And the grain refining ability of the Al_(2)Y particles was systematically evaluated in terms of the addition amounts,number density of the Al_(2)Y particles and holding time.The finest grains are achieved at 2 wt% Al_(2)Y addition amount,which corresponds to number density of the polygonal Al_(2)Y particles of 420-460 mm^(-2).The Mg-10Al_(2)Y master alloy has significant refinement performance and no refining recession occurs at the holding time within 60 min,or the settling time up to 180 min.Grain refinement and the second phase strengthening of uniformly distributed Al_(2)Y particles contribute to the simultaneous enhancement on both strength and elongation of Mg-3Y alloy.
基金financially supported by the National Natural Science Foundation of China (NSFC,No.21805024)Science Foundation of China University of Petroleum (Nos. 2462019QNXZ02,2462018BJC004)+1 种基金the Scientifc and Technological Research Program of Chongqing Municipal Education Commission (No.KJ QN202001335)the Research Program ofYongchuan Science and Technology Commission (Ycstc,No.2018nb1402)。
文摘Long-emission carbon dots(CDs) is triggering immense enthusiasm on account of their intrinsic merits of high chemical stability and excellent optical properties.In this study,a facile and rapid approach was developed for the preparation of barium-doped carbon dots(Ba-CDs) with yellow fluo rescence emission and high quantum yields.Surface chemistry and the chemical architecture of the Ba-CDs was revealed under various spectroscopic methods.This work provides more insights into the effects of charge transfer caused by Ba heteroatoms,which is considered as the most challenging step in the investigation on luminescence mechanism.Remarkably,the prepared Ba-CDs were successfully applied as fluorescent probes in the detection of trace water in organic solvents(ethanol,isopropanol,acetone,tetrahydrofuran).Comparing with traditional fluorescent probes for water detection in organic solvents,Ba-CDs detection provides a more sensitive,much faster and more economical approach.
基金sponsored by the Regional Joint Fund of the National Science Foundation of China(Grant No.U21A20492)the National Key R&D Program of China(Grant No.2018YFB0407102)+6 种基金the City University of Hong Kong(Grant Nos 9667221,9680322)the Research Grants Council of the Hong Kong Special Administrative Region(Grant No.21210820,11213721)the Shenzhen Science and Technology Innovation Commission(Grant No.JCYJ20200109110201713)the Natural Science Foundation of Chongqing Municipality(Grant No.cstc2019jcyjjqX0021)the Science and Technology Innovation Leading Talents Program of Chongqing Municipality(No:T04040012)Science and Technology of Sichuan Province(Grant No.2020YFH0181)the National Natural Science Foundation of China(NSFQ(Grant Nos.U21A20492,62122002).
文摘Origami has become an optimal methodological choice for creating complex three-dimensional(3D)structures and soft robots.The simple and low-cost origami-inspired folding assembly provides a new method for developing 3D soft robots,which is ideal for future intelligent robotic systems.Here,we present a series of materials,structural designs,and fabrication methods for developing independent,electrically controlled origami 3D soft robots for walking and soft manipulators.The 3D soft robots are based on soft actuators,which are multilayer structures with a dielectric elastomer(DE)film as the deformation layer and a laser-cut PET film as the supporting flexible frame.The triangular and rectangular design of the soft actuators allows them to be easily assembled into crawling soft robots and pyramidal-and square-shaped 3D structures.The crawling robot exhibits very stable crawling behaviors and can carry loads while walking.Inspired by origami folding,the pyramidal and square-shaped 3D soft robots exhibit programmable out-of-plane deformations and easy switching between two-dimensional(2D)and 3D structures.The electrically controllable origami deformation allows the 3D soft robots to be used as soft manipulators for grasping and precisely locking 3D objects.This work proves that origami-inspired fold-based assembly of DE actuators is a good reference for the development of soft actuators and future intelligent multifunctional soft robots.
