Micrometre-sized electrode materials have distinct advantages for battery applications in terms of energy density,processability,safety and cost.For the silicon monoxide anode that undergoes electrochemical alloying r...Micrometre-sized electrode materials have distinct advantages for battery applications in terms of energy density,processability,safety and cost.For the silicon monoxide anode that undergoes electrochemical alloying reaction with Li,the Li(de)intercalation by micron-sized active particles usually accompanies with a large volume variation,which pulverizes the particle structure and leads to rapidly faded storage performance.In this work,we proposed to stabilize the electrochemistry vs.Li of the micron-SiO_(x) anode by forming a rigid-flexible bi-layer coati ng on the particle surface.The coati ng consists of pyrolysis carbon as the inner layer and polydopamine as the outer layer.While the inner layer guarantees high structural rigidity at particle surface and provides efficient pathway for electron conduction,the outer layer shows high flexibility for maintaining the integrity of micrometre-sized particles against drastic volume variation,and together they facilitate formation of stable solid electrolyte interface on the SiO_(x) particles.A composite an ode prepared by mixing the coated micron-SiOx with graphite delivered improved Li storage performance,and promised a high-capacity,long-life LiFePO_(4)/SiO_(x)-graphite pouch cell.Our strategy provides a general and feasible solution for building high-energy rechargeable batteries from micrometre-sized electrode materials with significant volume variation.展开更多
The development of metal implants as permanent replacements for hard tissue involves careful consideration of both interfacial bone integration for load-bearing support and interfacial energy dissipation to prevent bo...The development of metal implants as permanent replacements for hard tissue involves careful consideration of both interfacial bone integration for load-bearing support and interfacial energy dissipation to prevent bone resorption due to excess load.Currently,most implants are typically limited to excelling in only one of these functions.A promising approach to achieving a synergistic effect of interfacial bone integration and energy dissipation is the design of a nanofiber-chitosan(nanofiber-CS)composite flexible coating on titanium alloy surfaces.However,the tribological properties of this flexible coating remain uncertain.In this study,the authors evaluated the tribological properties of pure titanium substrates and the nanofiber-cs composite flexible coating in both dry and wet environments.The results demonstrated that while the nanofiber-cs composite flexible coating reduced surface wear in dry conditions,it increased surface wear in wet environments.This indicates that there is potential for improvement in the tribological characteristics of the nanofiber-cs composite flexible coating,particularly in wet conditions.This research offers theoretical and technical insights into the design of flexible coatings for implant surfaces from a tribological standpoint.展开更多
Highly transparent,durable,and flexible liquid-repellent coatings are urgently needed in the realm of transparent materials,such as car windows,optical lenses,solar panels,and flexible screen materials.However,it has ...Highly transparent,durable,and flexible liquid-repellent coatings are urgently needed in the realm of transparent materials,such as car windows,optical lenses,solar panels,and flexible screen materials.However,it has been difficult to strike a balance between the robustness and flexibility of coatings constructed by a single cross-linked network design.To overcome the conundrum,this innovative approach effectively combines two distinct cross-linked networks with unique functions,thus overcoming the challenge.Through a tightly interwoven structure comprised of added crosslinking sites,the coating achieves improved liquid repellency(WCA>100°,OSA<10°),increased durability(withstands 2,000 cycles of cotton wear),enhanced flexibility(endures 5,000 cycles of bending with a bending radius of 1 mm),and maintains high transparency(over 98%in the range of 410 nm to 760 nm).Additionally,the coating with remarkable adhesion can be applied to multiple substrates,enabling large-scale preparation and easy cycling coating,thus expanding its potential applications.The architecture of this fluoride-free dual cross-linked network not only advances liquid-repellent surfaces but also provides valuable insights for the development of eco-friendly materials in the future.展开更多
As a common fault of the aero-engine,the blade-casing rubbing(BCR)has the potential to cause catastrophic accidents.In this paper,to investigate the dynamic responses and wear characteristics of the system,the laminat...As a common fault of the aero-engine,the blade-casing rubbing(BCR)has the potential to cause catastrophic accidents.In this paper,to investigate the dynamic responses and wear characteristics of the system,the laminated shell element is used to establish the finite element model(FEM)of a flexibly coated casing system.Using the shell element,the blade is modeled,and the surface stress of the blade is calculated.The stress-solving method of the blade is validated through comparisons with the measured time-domain waveform of the stress.Then,a dynamic model of a blade-flexibly coated casing system with rubbing is proposed,accounting for the time-varying mass and stiffness of the casing caused by coating wear.The effects of the proposed flexible casing model are compared with those of a rigid casing model,and the stress changes induced by rubbing are investigated.The results show that the natural characteristics of the coated casing decrease due to the coating wear.The flexibly coated casing model is found to be more suitable for studying casing vibration.Additionally,the stress changes caused by rubbing are slight,and the change in the stress maximum is approximately 5%under the influence of the abrasive coating.展开更多
Mosquitoes possess the striking ability to walk on water because each of their legs has a huge water supporting force（WSF） that is 23 times their body weight.Aiming at a full understanding of the origins of this ext...Mosquitoes possess the striking ability to walk on water because each of their legs has a huge water supporting force（WSF） that is 23 times their body weight.Aiming at a full understanding of the origins of this extremely large force,in this study,we concentrate on two aspects of it：the intrinsic properties of the leg surface and the active control of the initial stepping angle of the whole leg.Using a measurement system that we developed ourselves,the WSFs for the original leg samples are compared with those whose surface wax and microstructures have been removed and with those of a different stiffness.The results show that leg f exibility plays a dominant role over surface wax and microstructures on the leg surface in creating the supporting force.Moreover,we discuss the dependence relationship between the maximum WSF and the initial stepping angle,which indicates that the mosquito can regulate this angle to increase or decrease the WSF during landing or takeoff.These finding are helpful for uncovering the locomotion mechanism of aquatic insects and for providing inspiration for the design of microfluids miniature boats,biomimetic robots,and microsensors.展开更多
基金supported by the Innovation Team for R&D and Industrialization of High Energy Density Si-based Power batteries (2018607219003)the Basic Science Center Project of National Natural Science Foundation of China (51788104)+2 种基金the National Key R&D Program of China (2019YFA0705600)the “Transformational Technologies for Clean Energy and Demonstration”Strategic Priority Research Program of the Chinese Academy of Sciences (XDA21070300).
文摘Micrometre-sized electrode materials have distinct advantages for battery applications in terms of energy density,processability,safety and cost.For the silicon monoxide anode that undergoes electrochemical alloying reaction with Li,the Li(de)intercalation by micron-sized active particles usually accompanies with a large volume variation,which pulverizes the particle structure and leads to rapidly faded storage performance.In this work,we proposed to stabilize the electrochemistry vs.Li of the micron-SiO_(x) anode by forming a rigid-flexible bi-layer coati ng on the particle surface.The coati ng consists of pyrolysis carbon as the inner layer and polydopamine as the outer layer.While the inner layer guarantees high structural rigidity at particle surface and provides efficient pathway for electron conduction,the outer layer shows high flexibility for maintaining the integrity of micrometre-sized particles against drastic volume variation,and together they facilitate formation of stable solid electrolyte interface on the SiO_(x) particles.A composite an ode prepared by mixing the coated micron-SiOx with graphite delivered improved Li storage performance,and promised a high-capacity,long-life LiFePO_(4)/SiO_(x)-graphite pouch cell.Our strategy provides a general and feasible solution for building high-energy rechargeable batteries from micrometre-sized electrode materials with significant volume variation.
基金The project was supported by the National Natural Science Foundation of China(52,205,198)smart medicine and engineering interdisciplinary innovation project of Ningbo University(ZHYG001).
文摘The development of metal implants as permanent replacements for hard tissue involves careful consideration of both interfacial bone integration for load-bearing support and interfacial energy dissipation to prevent bone resorption due to excess load.Currently,most implants are typically limited to excelling in only one of these functions.A promising approach to achieving a synergistic effect of interfacial bone integration and energy dissipation is the design of a nanofiber-chitosan(nanofiber-CS)composite flexible coating on titanium alloy surfaces.However,the tribological properties of this flexible coating remain uncertain.In this study,the authors evaluated the tribological properties of pure titanium substrates and the nanofiber-cs composite flexible coating in both dry and wet environments.The results demonstrated that while the nanofiber-cs composite flexible coating reduced surface wear in dry conditions,it increased surface wear in wet environments.This indicates that there is potential for improvement in the tribological characteristics of the nanofiber-cs composite flexible coating,particularly in wet conditions.This research offers theoretical and technical insights into the design of flexible coatings for implant surfaces from a tribological standpoint.
基金financially supported by the National Natu-ral Science Foundation of China(Nos.22375047,22378068,and 22075046)the Natural Science Foundation of Fujian Province(No.2022J01568)+2 种基金the National Key Research and Development Program of China(Nos.2022YFB3804905 and 2022YFB3804900)China Postdoctoral Science Foundation(No.2023M743437)start-up funding from Wenzhou Institute,University of Chinese Academy of Sciences(No.WIUCASQD2019002).
文摘Highly transparent,durable,and flexible liquid-repellent coatings are urgently needed in the realm of transparent materials,such as car windows,optical lenses,solar panels,and flexible screen materials.However,it has been difficult to strike a balance between the robustness and flexibility of coatings constructed by a single cross-linked network design.To overcome the conundrum,this innovative approach effectively combines two distinct cross-linked networks with unique functions,thus overcoming the challenge.Through a tightly interwoven structure comprised of added crosslinking sites,the coating achieves improved liquid repellency(WCA>100°,OSA<10°),increased durability(withstands 2,000 cycles of cotton wear),enhanced flexibility(endures 5,000 cycles of bending with a bending radius of 1 mm),and maintains high transparency(over 98%in the range of 410 nm to 760 nm).Additionally,the coating with remarkable adhesion can be applied to multiple substrates,enabling large-scale preparation and easy cycling coating,thus expanding its potential applications.The architecture of this fluoride-free dual cross-linked network not only advances liquid-repellent surfaces but also provides valuable insights for the development of eco-friendly materials in the future.
基金Project supported by the National Science and Technology Major Project(No.J2022-IV-0005-0022)the Aero Science Foundation of China(No.20230015050001)the Shenyang Science and Technology Plan Project of China(No.24-202-6-01)。
文摘As a common fault of the aero-engine,the blade-casing rubbing(BCR)has the potential to cause catastrophic accidents.In this paper,to investigate the dynamic responses and wear characteristics of the system,the laminated shell element is used to establish the finite element model(FEM)of a flexibly coated casing system.Using the shell element,the blade is modeled,and the surface stress of the blade is calculated.The stress-solving method of the blade is validated through comparisons with the measured time-domain waveform of the stress.Then,a dynamic model of a blade-flexibly coated casing system with rubbing is proposed,accounting for the time-varying mass and stiffness of the casing caused by coating wear.The effects of the proposed flexible casing model are compared with those of a rigid casing model,and the stress changes induced by rubbing are investigated.The results show that the natural characteristics of the coated casing decrease due to the coating wear.The flexibly coated casing model is found to be more suitable for studying casing vibration.Additionally,the stress changes caused by rubbing are slight,and the change in the stress maximum is approximately 5%under the influence of the abrasive coating.
基金supported by the National Natural Science Foundation of China (Grants 11302093,11302094 and 11272357)the Natural Science Fund for Distinguished Young Scholars of Shandong Province (JQ201302)
文摘Mosquitoes possess the striking ability to walk on water because each of their legs has a huge water supporting force（WSF） that is 23 times their body weight.Aiming at a full understanding of the origins of this extremely large force,in this study,we concentrate on two aspects of it：the intrinsic properties of the leg surface and the active control of the initial stepping angle of the whole leg.Using a measurement system that we developed ourselves,the WSFs for the original leg samples are compared with those whose surface wax and microstructures have been removed and with those of a different stiffness.The results show that leg f exibility plays a dominant role over surface wax and microstructures on the leg surface in creating the supporting force.Moreover,we discuss the dependence relationship between the maximum WSF and the initial stepping angle,which indicates that the mosquito can regulate this angle to increase or decrease the WSF during landing or takeoff.These finding are helpful for uncovering the locomotion mechanism of aquatic insects and for providing inspiration for the design of microfluids miniature boats,biomimetic robots,and microsensors.
