Droplet impact dynamics on solid surfaces,which are ubiquitously present in aerospace engineering,energy systems,agricultural production,etc.,involve complex fluid–structure interactions.Herein,we employ a single-cam...Droplet impact dynamics on solid surfaces,which are ubiquitously present in aerospace engineering,energy systems,agricultural production,etc.,involve complex fluid–structure interactions.Herein,we employ a single-camera high-speed threedimensional digital image correlation system to quantify the full-field deformations of flexible thin films during droplet impact dynamics.Experimental results revealed that the substrate flexibility not only reduces the maximum spreading diameter by 10%but also modulates rebound dynamics via energy competition between kinetic energy and surface adhesion energy,suggesting that coupled deformation of the solid–fluid interface plays an important role in the dynamic progress.We propose the structure-coupled response number(Sn),a governing dimensionless parameter unifying droplet spreading on both rigid and flexible films,validated by a universal 1/2 scaling law.A theoretical criterion for droplet rebound on hydrophobic flexible thin films is derived and experimentally demonstrated,which achieves the precise control of droplet rebound/non-rebound mode.This work bridges the theories of droplet impact dynamics on rigid and flexible substrates,offering a robust strategy to govern the droplet impact behaviors.展开更多
Electrocatalytic water splitting stands at the forefront for advancing renewable energy technologies.A critical challenge in this realm is the detrimental effect of gas bubble adhesion on electrode surfaces,which impa...Electrocatalytic water splitting stands at the forefront for advancing renewable energy technologies.A critical challenge in this realm is the detrimental effect of gas bubble adhesion on electrode surfaces,which impairs electrochemical efficiency.Addressing this,our study introduces a superaerophobic nickelbased catalyst,innovatively fabricated through electrodeposition on pencil-drawn,non-conductive A4 paper.The catalyst’s distinctive feature arises from phosphorus(P)doping,which instigates lattice contraction in the nickel metal,culminating in a cracked surface topology.This morphological alteration is demonstrated to engender superaerophobic properties,a conclusion substantiated by comprehensive first-principles calculations and meticulous surface tension measurements.The electrocatalyst showcases enhanced performance in water splitting,primarily attributed to the minimal gas bubble adhesion on its superaerophobic surface.This performance notably surpasses that of commercial Pt plates,especially at elevated current densities.Additionally,P-doping plays a pivotal role in bolstering the electrode’s corrosion resistance against the electrolyte,thereby augmenting its structural stability and longevity.Our findings pave the way for a novel and efficacious approach for developing high-performance electrocatalysts,offering significant promise for sustainable and efficient hydrogen production in renewable energy applications.展开更多
The fabrication of electronic devices utilizing single-molecule magnets(SMMs)requires deposition on conducting surfaces,which usually consist of thiophilic elements such as gold,silver and copper.Thus,SMMs possessing ...The fabrication of electronic devices utilizing single-molecule magnets(SMMs)requires deposition on conducting surfaces,which usually consist of thiophilic elements such as gold,silver and copper.Thus,SMMs possessing sulphur-containing ligands that are capable of attaching on such surfaces through chemical bonding are fascinating.Here,we designed and successfully isolated a series of pentagonalbipyramidal dysprosium(Ⅲ)compounds with a sulfur-containing macrocycle PYNS ligand,[Dy(L_(A))_(2)(PYNS)][BPh_(4)](PYNS=2,6-bis(4-(pyridin-2-yl)thiazol-2-yl)pyridine);L_(A)^(−)=^(t)BuO^(−)for 1Dy;(S)-PhEtO^(−)for 2Dy;CF_(3)PhMeO^(−)for 3Dy;Ph_(3)SiO^(−)for 4Dy;(^(t)BuO)_(3)SiO^(−)for 5Dy).They exhibit zero-field SMM behaviour with effective energy barriers U_(eff) between 679 and 807 K,and the magnetic blocking temperatures T_(B)^(IRREV) for 3Dy and 5Dy were determined to be 2.5 K while,that of 4Dy is 3 K.The sulfur atoms at the peripheral position of PYNS are expected to act as linkers to adsorb the molecules onto gold surfaces.展开更多
Vibration is a common strategy for aquatic organisms to achieve their life activities,especially at the air-water interface.For the locomotion of small creatures,the organs with plate features are often used on water ...Vibration is a common strategy for aquatic organisms to achieve their life activities,especially at the air-water interface.For the locomotion of small creatures,the organs with plate features are often used on water surfaces,which inspires relevant studies about using thin plates for robot propulsions.However,the influence of the general deformations of thin plates on the generated flow fields has not been considered.Here,a comprehensive investigation is conducted about the flow fields that arose by vibrations of thin plates and the potential as locomotion strategies are explored.It is discovered that as thin plates are subjected to vibration excitations on the water surface,the produced flow fields are mainly determined by the vibration shapes,and the influence rules of plate deformations on the flow fields are identified.The main factors producing asymmetric flow fields are analyzed to realize the morphology control of the flow fields.Then,to determine effective locomotion strategies on the water surface,the flow fields stimulated by integrated vibration exciters are explored,and 2 water surface robots are developed consequentially.which exhibit superior motion performance.This work reveals the basic rules of the vibration-induced-flow mechanism by thin plates and establishes new locomotion strategies for aquatic robots.展开更多
基金supported by the National Key R&D Program of China(grant nos.2022YFF0503500 and 2022YFA1203200)the Guangdong Basic and Applied Basic Research Foundation(grant no.2023A1515011784)+2 种基金the National Natural Science Foundation of China(grant no.12032019)the Strategic Priority Research Program of Chinese Academy of Sciences(grant nos.XDB0620101 and XDB0620103)the Youth Innovation Promotion Association,Chinese Academy of Sciences(no.2020020).
文摘Droplet impact dynamics on solid surfaces,which are ubiquitously present in aerospace engineering,energy systems,agricultural production,etc.,involve complex fluid–structure interactions.Herein,we employ a single-camera high-speed threedimensional digital image correlation system to quantify the full-field deformations of flexible thin films during droplet impact dynamics.Experimental results revealed that the substrate flexibility not only reduces the maximum spreading diameter by 10%but also modulates rebound dynamics via energy competition between kinetic energy and surface adhesion energy,suggesting that coupled deformation of the solid–fluid interface plays an important role in the dynamic progress.We propose the structure-coupled response number(Sn),a governing dimensionless parameter unifying droplet spreading on both rigid and flexible films,validated by a universal 1/2 scaling law.A theoretical criterion for droplet rebound on hydrophobic flexible thin films is derived and experimentally demonstrated,which achieves the precise control of droplet rebound/non-rebound mode.This work bridges the theories of droplet impact dynamics on rigid and flexible substrates,offering a robust strategy to govern the droplet impact behaviors.
基金funding support from the National Natural Science Foundation of China(52375204)the World First Class University and First Class Academic Discipline Construction Funding 2023(0206023GH0202 and 0206023SH0201)+3 种基金Shaanxi Provincial Science and Technology Innovation Team under grant code 2024RS-CXTD-63the funding support from the Hong Kong Polytechnic University(project number:1-BE47,ZE0C,ZE2F and ZE2X)the funding support from the National Natural Science Foundation of China(51401084)the Natural Science Foundation of Jiangxi,China(20232ACB203002).
文摘Electrocatalytic water splitting stands at the forefront for advancing renewable energy technologies.A critical challenge in this realm is the detrimental effect of gas bubble adhesion on electrode surfaces,which impairs electrochemical efficiency.Addressing this,our study introduces a superaerophobic nickelbased catalyst,innovatively fabricated through electrodeposition on pencil-drawn,non-conductive A4 paper.The catalyst’s distinctive feature arises from phosphorus(P)doping,which instigates lattice contraction in the nickel metal,culminating in a cracked surface topology.This morphological alteration is demonstrated to engender superaerophobic properties,a conclusion substantiated by comprehensive first-principles calculations and meticulous surface tension measurements.The electrocatalyst showcases enhanced performance in water splitting,primarily attributed to the minimal gas bubble adhesion on its superaerophobic surface.This performance notably surpasses that of commercial Pt plates,especially at elevated current densities.Additionally,P-doping plays a pivotal role in bolstering the electrode’s corrosion resistance against the electrolyte,thereby augmenting its structural stability and longevity.Our findings pave the way for a novel and efficacious approach for developing high-performance electrocatalysts,offering significant promise for sustainable and efficient hydrogen production in renewable energy applications.
基金supported by the National Natural Science Foundation of China(No.22375157)the Fundamental Research Funds for Central Universities(No.xtr052023002)+1 种基金the Special Support Plan of Shaanxi Province for Young Topnotch Talent,the Medical-Engineering Cross Project of the First Affiliated Hospital of XJTU(No.QYJC02)Programme of Introducing Talents of Discipline to Universities(B23025).
文摘The fabrication of electronic devices utilizing single-molecule magnets(SMMs)requires deposition on conducting surfaces,which usually consist of thiophilic elements such as gold,silver and copper.Thus,SMMs possessing sulphur-containing ligands that are capable of attaching on such surfaces through chemical bonding are fascinating.Here,we designed and successfully isolated a series of pentagonalbipyramidal dysprosium(Ⅲ)compounds with a sulfur-containing macrocycle PYNS ligand,[Dy(L_(A))_(2)(PYNS)][BPh_(4)](PYNS=2,6-bis(4-(pyridin-2-yl)thiazol-2-yl)pyridine);L_(A)^(−)=^(t)BuO^(−)for 1Dy;(S)-PhEtO^(−)for 2Dy;CF_(3)PhMeO^(−)for 3Dy;Ph_(3)SiO^(−)for 4Dy;(^(t)BuO)_(3)SiO^(−)for 5Dy).They exhibit zero-field SMM behaviour with effective energy barriers U_(eff) between 679 and 807 K,and the magnetic blocking temperatures T_(B)^(IRREV) for 3Dy and 5Dy were determined to be 2.5 K while,that of 4Dy is 3 K.The sulfur atoms at the peripheral position of PYNS are expected to act as linkers to adsorb the molecules onto gold surfaces.
基金supported by the National Natural Science Foundation of China(no.52225501)the State Key Laboratory of Robotics and System(HIT)(no.SKLRS-2022-ZM-01).
文摘Vibration is a common strategy for aquatic organisms to achieve their life activities,especially at the air-water interface.For the locomotion of small creatures,the organs with plate features are often used on water surfaces,which inspires relevant studies about using thin plates for robot propulsions.However,the influence of the general deformations of thin plates on the generated flow fields has not been considered.Here,a comprehensive investigation is conducted about the flow fields that arose by vibrations of thin plates and the potential as locomotion strategies are explored.It is discovered that as thin plates are subjected to vibration excitations on the water surface,the produced flow fields are mainly determined by the vibration shapes,and the influence rules of plate deformations on the flow fields are identified.The main factors producing asymmetric flow fields are analyzed to realize the morphology control of the flow fields.Then,to determine effective locomotion strategies on the water surface,the flow fields stimulated by integrated vibration exciters are explored,and 2 water surface robots are developed consequentially.which exhibit superior motion performance.This work reveals the basic rules of the vibration-induced-flow mechanism by thin plates and establishes new locomotion strategies for aquatic robots.
