Piezoresistive pressure sensors have received considerable attention because of their simple structure,high sensitivity and low cost.Graphene,which is known for its outstanding mechanical and electrical properties,has...Piezoresistive pressure sensors have received considerable attention because of their simple structure,high sensitivity and low cost.Graphene,which is known for its outstanding mechanical and electrical properties,has shown great application potential as a sensor material.However,its durability and performance consistency in practical applications still require enhancement.In this study,magnetic graphene fibers(MGFs)are prepared via wet spinning,using graphene oxide(GO),doped with Fe_(3)O_(4)nanoparticles.The resulting MGFs exhibit a high tensile strength of 58.6 MPa,a strain of 5.3%and an electrical conductivity of 1.7×10^(4)S/m.These MGFs are utilised to construct a multilayer fabric for fabrication of flexible pressure sensors.The confinement within the spinning channel facilitates an ordered arrangement of GO sheets,resulting in MGFs with superior electrical and mechanical properties.The issuing MGFs pressure sensors demonstrate a wide detection range(0-120 kPa),high sensitivity(0.233 kPa^(−1),0-40 kPa)and rapid response/recovery times(121 ms/158 ms).In addition,it exhibits a remarkable durability,maintaining performance over 1300 cycles,during continuous operation,with negligible degradation.This sensor shows excellent capability in monitoring human physiological activities,indicating its substantial application potential in wearable devices.展开更多
The design procedure of a dense gap-graded friction course（DGGFC） with coarse aggregate void filling method is presented. Testing results show that a DGGFC mixture possesses a dense stone-matrix structure, good stab...The design procedure of a dense gap-graded friction course（DGGFC） with coarse aggregate void filling method is presented. Testing results show that a DGGFC mixture possesses a dense stone-matrix structure, good stability and almost the same texture depth as stone matrix asphalt （SMA）. It also has a coarse and even surface after paving and has no separation during construction. It is durable and impermeable. It balances and improves the inherent inconsistency of asphalt mixture between the large texture depth for skid resistance and the impermeability for durability. The actual application in the Nanning-Liuzhou Expressway also shows that the performance of the DGGFC is as excellent as that of SMA, while the DGGFC mixture is cheaper than SMA. The DGGFC mixture is good for wearing course of pavement. Further research on DGGFC can be helpful for improving the surface skid resistance, prolonging the life-span period and reducing the construction costs of asphalt pavement.展开更多
We discuss the dynamical behavior of strange quark matter components, in particular the effects of density dependent quark mass on the equation of state of strange quark matter. The dynamical masses of quarks are comp...We discuss the dynamical behavior of strange quark matter components, in particular the effects of density dependent quark mass on the equation of state of strange quark matter. The dynamical masses of quarks are computed within the Nambu-Jona-Lasinio model, then we perform strange quark matter calculations em- ploying the MIT bag model with these dynamical masses. For the sake of compar- ing dynamical mass interaction with QCD quark-quark interaction, we consider the one-gluon-exchange term as the effective interaction between quarks for the MIT bag model. Our dynamical approach illustrates an improvement in the obtained equation of state values. We also investigate the structure of the strange quark star using Tolman- Oppenheimer-Volkoff equations for all applied models. Our results show that dynamical mass interaction leads to lower values for gravitational mass.展开更多
The possibility to produce advanced alumina and zirconia ceramics by the electroconsolidation method is studied. The technological parameters of Al2O3 and ZrO2 （3 mass% Y2O3 ） production were developed and optimized...The possibility to produce advanced alumina and zirconia ceramics by the electroconsolidation method is studied. The technological parameters of Al2O3 and ZrO2 （3 mass% Y2O3 ） production were developed and optimized. Electroconsolidated alumina and zirconia ceramics have higher values of properties in comparison with ordinary sintered samples in air. Advanced proper- ties of electroconsolidated ceramics are defined by homo- geneous, ultradense and fine-crystalline structure that was formed due to the effect to consolidate the materials to high density for a shortest time.展开更多
We have calculated the structural properties of a strange quark star with a static model in the presence of a strong magnetic field. To this end, we use the MIT bag model with a density dependent bag constant. To para...We have calculated the structural properties of a strange quark star with a static model in the presence of a strong magnetic field. To this end, we use the MIT bag model with a density dependent bag constant. To parameterize the density dependence of the bag constant, we have used our results for the lowest order constrained variational calculation of the asymmetric nuclear matter. By calculating the equation of state of strange quark matter, we have shown that the pressure of this system increases by increasing both density and magnetic field. Finally, we have investigated the effect of density dependence of the bag constant on the structural properties of a strange quark star.展开更多
High conductivity two-dimensional(2D)materials have been proved to be potential electrode materials for flexible supercapacitors because of its outstanding chemical and physical properties.However,electrodes based on ...High conductivity two-dimensional(2D)materials have been proved to be potential electrode materials for flexible supercapacitors because of its outstanding chemical and physical properties.However,electrodes based on 2D materials always suffer from limited electrolyte-accessible surface due to the restacking of the 2D sheets,hindering the full utilization of their surface area.In this regard,an electrolyte-mediated method is used to integrate dense structure reduced graphene oxide/MXene(RGM)-electrolyte composite films.In such composite films,reduced graphene oxide(RGO)and MXene sheets are controllable assembly in compact layered structure with electrolyte filled between the layers.The electrolyte layer between RGO and MXene sheets forms continuous ion transport channels in the composite films.Therefore,the RGM-electrolyte composite films can be used directly as self-supporting electrodes for supercapacitors without additional conductive agents and binders.As a result,the composite films demonstrate enhanced volumetric specific capacity,improved volumetric energy density and higher power density compared with both pure RGO electrode and porous composite electrode prepared by traditional methods.Specifically,when the mass ratio of MXene is 30%,the electrode delivers a volumetric specific capacity of 454.9 F·cm^(−3) with a high energy density of 39.4 Wh·L^(−1).More importantly,supercapacitors based on the composite films exhibit good flexibility electrochemical performance.The investigation provides a new approach to synthesize dense structure films based on 2D materials for application in high volumetric capacitance flexible supercapacitors.展开更多
Displacement is a critical indicator for mechanical systems and civil structures.Conventional vision-based displacement recognition methods mainly focus on the sparse identification of limited measurement points,and t...Displacement is a critical indicator for mechanical systems and civil structures.Conventional vision-based displacement recognition methods mainly focus on the sparse identification of limited measurement points,and the motion representation of an entire structure is very challenging.This study proposes a novel Nodes2STRNet for structural dense displacement recognition using a handful of structural control nodes based on a deformable structural three-dimensional mesh model,which consists of control node estimation subnetwork(NodesEstimate)and pose parameter recognition subnetwork(Nodes2PoseNet).NodesEstimate calculates the dense optical flow field based on FlowNet 2.0 and generates structural control node coordinates.Nodes2PoseNet uses structural control node coordinates as input and regresses structural pose parameters by a multilayer perceptron.A self-supervised learning strategy is designed with a mean square error loss and L2 regularization to train Nodes2PoseNet.The effectiveness and accuracy of dense displacement recognition and robustness to light condition variations are validated by seismic shaking table tests of a four-story-building model.Comparative studies with image-segmentation-based Structure-PoseNet show that the proposed Nodes2STRNet can achieve higher accuracy and better robustness against light condition variations.In addition,NodesEstimate does not require retraining when faced with new scenarios,and Nodes2PoseNet has high self-supervised training efficiency with only a few control nodes instead of fully supervised pixel-level segmentation.展开更多
Controlling the orientation of two-dimensional MXene within layered films is essential to optimize or tune their mechanical properties and electromagnetic interference shielding(EMI)performance,but achieving the high ...Controlling the orientation of two-dimensional MXene within layered films is essential to optimize or tune their mechanical properties and electromagnetic interference shielding(EMI)performance,but achieving the high orientation MXene layers on an industrial scale remains a challenging goal.In this paper,a scalable layer-by-layer blade coating(LbLBC)method was employed to fabricate highly oriented MXene/polyvinyl alcohol(PVA)films.During the LbLBC process,MXene/PVA colloid suffered a strong shearing effect,which induced the ordered alignment of MXene nanosheets along the direction of the blade movement.The orientation of MXene can be effectively adjusted by changing the scraping gap of LbLBC,achieving a maximum Herman orientation factor f of 0.81.As a result,the mechanical properties and EMI performance of the as-prepared MXene/PVA films are in direct proportion to their orientation,with the optimal values of tensile strength of 145.5 MPa,fracture strain of 19.6%,toughness of 17.7 MJ·m^(−3),and EMI shielding effectiveness of 36.7 dB.Furthermore,the inherently low mid-infrared(mid-IR)emissivity of MXene,combined with the densely oriented structure affords the composite films with IR stealth,resulting in a substantial decrease from 150 to 66.1℃in the radiative temperature of a surface.Conclusively,these scalable MXene/PVA films exhibit remarkable potential for integration into the next generation of multifunctional protective camouflage materials.展开更多
Untethered and self-transformable miniature robots are capable of performing reconfigurable deformation and on-demand locomotion,which aid the traversal toward various lumens,and bring revolutionary changes for target...Untethered and self-transformable miniature robots are capable of performing reconfigurable deformation and on-demand locomotion,which aid the traversal toward various lumens,and bring revolutionary changes for targeted delivery in gastrointestinal(GI)tract.However,the viscous non-Newtonian liquid environment and plicae gastricae obstacles severely hamper high-precision actuation and payload delivery.Here,we developed a low-friction soft robot by assembly of densely arranged cone structures and grafting of hydrophobic monolayers.The magnetic orientation encoded robot can move in multiple modes,with a substantially reduced drag,terrain adaptability,and improved motion velocity across the non-Newtonian liquids.Notably,the robot stiffness can be reversibly controlled with magnetically induced hardening,enabling on-site scratching and destruction of antibiotic-ineradicable polymeric matrix in biofilms with a low-frequency magnetic field.Furthermore,the magnetocaloric effect can be utilized to eradicate the bacteria by magnetocaloric effect under high-frequency alternating field.To verify the potential applications inside the body,the clinical imaging-guided actuation platforms were developed for vision-based control and delivery of the robots.The developed low-friction robots and clinical imaging-guided actuation platforms show their high potential to perform bacterial infection therapy in various lumens inside the body.展开更多
基金supported by Zhejiang Natural Science Foundation Technology Project(LGG22E030015)National Key Research and Development Program of China support by Ministry of Science and Technology(2022YFB3704504)+5 种基金Jiaxing Science and Technology Plan Project(2023AY11004)Jiaxing Project of Science and Technology(2023AY11014)Jiaxing University General Cultivation Project(00321056AL)Qinshen Youth Backbone Training Program of Jiaxing University(CD70623038)Jiaxing City Public Welfare Project(Young Talent Special Project)(2023AY40027)Key Laboratory of Yarn Materials Forming and Composite Processing Technology,Zhejiang Province(MTC-2022-06).
文摘Piezoresistive pressure sensors have received considerable attention because of their simple structure,high sensitivity and low cost.Graphene,which is known for its outstanding mechanical and electrical properties,has shown great application potential as a sensor material.However,its durability and performance consistency in practical applications still require enhancement.In this study,magnetic graphene fibers(MGFs)are prepared via wet spinning,using graphene oxide(GO),doped with Fe_(3)O_(4)nanoparticles.The resulting MGFs exhibit a high tensile strength of 58.6 MPa,a strain of 5.3%and an electrical conductivity of 1.7×10^(4)S/m.These MGFs are utilised to construct a multilayer fabric for fabrication of flexible pressure sensors.The confinement within the spinning channel facilitates an ordered arrangement of GO sheets,resulting in MGFs with superior electrical and mechanical properties.The issuing MGFs pressure sensors demonstrate a wide detection range(0-120 kPa),high sensitivity(0.233 kPa^(−1),0-40 kPa)and rapid response/recovery times(121 ms/158 ms).In addition,it exhibits a remarkable durability,maintaining performance over 1300 cycles,during continuous operation,with negligible degradation.This sensor shows excellent capability in monitoring human physiological activities,indicating its substantial application potential in wearable devices.
文摘The design procedure of a dense gap-graded friction course（DGGFC） with coarse aggregate void filling method is presented. Testing results show that a DGGFC mixture possesses a dense stone-matrix structure, good stability and almost the same texture depth as stone matrix asphalt （SMA）. It also has a coarse and even surface after paving and has no separation during construction. It is durable and impermeable. It balances and improves the inherent inconsistency of asphalt mixture between the large texture depth for skid resistance and the impermeability for durability. The actual application in the Nanning-Liuzhou Expressway also shows that the performance of the DGGFC is as excellent as that of SMA, while the DGGFC mixture is cheaper than SMA. The DGGFC mixture is good for wearing course of pavement. Further research on DGGFC can be helpful for improving the surface skid resistance, prolonging the life-span period and reducing the construction costs of asphalt pavement.
基金supported by the Research Institute for Astronomy and Astrophysics of Maragha
文摘We discuss the dynamical behavior of strange quark matter components, in particular the effects of density dependent quark mass on the equation of state of strange quark matter. The dynamical masses of quarks are computed within the Nambu-Jona-Lasinio model, then we perform strange quark matter calculations em- ploying the MIT bag model with these dynamical masses. For the sake of compar- ing dynamical mass interaction with QCD quark-quark interaction, we consider the one-gluon-exchange term as the effective interaction between quarks for the MIT bag model. Our dynamical approach illustrates an improvement in the obtained equation of state values. We also investigate the structure of the strange quark star using Tolman- Oppenheimer-Volkoff equations for all applied models. Our results show that dynamical mass interaction leads to lower values for gravitational mass.
文摘The possibility to produce advanced alumina and zirconia ceramics by the electroconsolidation method is studied. The technological parameters of Al2O3 and ZrO2 （3 mass% Y2O3 ） production were developed and optimized. Electroconsolidated alumina and zirconia ceramics have higher values of properties in comparison with ordinary sintered samples in air. Advanced proper- ties of electroconsolidated ceramics are defined by homo- geneous, ultradense and fine-crystalline structure that was formed due to the effect to consolidate the materials to high density for a shortest time.
基金the Research Institute for Astronomy and Astrophysics of Maragha
文摘We have calculated the structural properties of a strange quark star with a static model in the presence of a strong magnetic field. To this end, we use the MIT bag model with a density dependent bag constant. To parameterize the density dependence of the bag constant, we have used our results for the lowest order constrained variational calculation of the asymmetric nuclear matter. By calculating the equation of state of strange quark matter, we have shown that the pressure of this system increases by increasing both density and magnetic field. Finally, we have investigated the effect of density dependence of the bag constant on the structural properties of a strange quark star.
基金This work was supported by the Natural Science Foundation of Shandong Province(Nos.ZR2018BB038 and ZR2019BEM041)the National Natural Science Foundation of China(Nos.21805171,51802178 and 51804189).
文摘High conductivity two-dimensional(2D)materials have been proved to be potential electrode materials for flexible supercapacitors because of its outstanding chemical and physical properties.However,electrodes based on 2D materials always suffer from limited electrolyte-accessible surface due to the restacking of the 2D sheets,hindering the full utilization of their surface area.In this regard,an electrolyte-mediated method is used to integrate dense structure reduced graphene oxide/MXene(RGM)-electrolyte composite films.In such composite films,reduced graphene oxide(RGO)and MXene sheets are controllable assembly in compact layered structure with electrolyte filled between the layers.The electrolyte layer between RGO and MXene sheets forms continuous ion transport channels in the composite films.Therefore,the RGM-electrolyte composite films can be used directly as self-supporting electrodes for supercapacitors without additional conductive agents and binders.As a result,the composite films demonstrate enhanced volumetric specific capacity,improved volumetric energy density and higher power density compared with both pure RGO electrode and porous composite electrode prepared by traditional methods.Specifically,when the mass ratio of MXene is 30%,the electrode delivers a volumetric specific capacity of 454.9 F·cm^(−3) with a high energy density of 39.4 Wh·L^(−1).More importantly,supercapacitors based on the composite films exhibit good flexibility electrochemical performance.The investigation provides a new approach to synthesize dense structure films based on 2D materials for application in high volumetric capacitance flexible supercapacitors.
文摘Displacement is a critical indicator for mechanical systems and civil structures.Conventional vision-based displacement recognition methods mainly focus on the sparse identification of limited measurement points,and the motion representation of an entire structure is very challenging.This study proposes a novel Nodes2STRNet for structural dense displacement recognition using a handful of structural control nodes based on a deformable structural three-dimensional mesh model,which consists of control node estimation subnetwork(NodesEstimate)and pose parameter recognition subnetwork(Nodes2PoseNet).NodesEstimate calculates the dense optical flow field based on FlowNet 2.0 and generates structural control node coordinates.Nodes2PoseNet uses structural control node coordinates as input and regresses structural pose parameters by a multilayer perceptron.A self-supervised learning strategy is designed with a mean square error loss and L2 regularization to train Nodes2PoseNet.The effectiveness and accuracy of dense displacement recognition and robustness to light condition variations are validated by seismic shaking table tests of a four-story-building model.Comparative studies with image-segmentation-based Structure-PoseNet show that the proposed Nodes2STRNet can achieve higher accuracy and better robustness against light condition variations.In addition,NodesEstimate does not require retraining when faced with new scenarios,and Nodes2PoseNet has high self-supervised training efficiency with only a few control nodes instead of fully supervised pixel-level segmentation.
基金the National Natural Science Foundation of China(Nos.52273085,52303113,and 12072325)the Natural Science Foundation of China of Henan Province(No.222300420541)the Key Scientific Research Projects of Colleges and Universities in Henan Province,China(No.24A430045).
文摘Controlling the orientation of two-dimensional MXene within layered films is essential to optimize or tune their mechanical properties and electromagnetic interference shielding(EMI)performance,but achieving the high orientation MXene layers on an industrial scale remains a challenging goal.In this paper,a scalable layer-by-layer blade coating(LbLBC)method was employed to fabricate highly oriented MXene/polyvinyl alcohol(PVA)films.During the LbLBC process,MXene/PVA colloid suffered a strong shearing effect,which induced the ordered alignment of MXene nanosheets along the direction of the blade movement.The orientation of MXene can be effectively adjusted by changing the scraping gap of LbLBC,achieving a maximum Herman orientation factor f of 0.81.As a result,the mechanical properties and EMI performance of the as-prepared MXene/PVA films are in direct proportion to their orientation,with the optimal values of tensile strength of 145.5 MPa,fracture strain of 19.6%,toughness of 17.7 MJ·m^(−3),and EMI shielding effectiveness of 36.7 dB.Furthermore,the inherently low mid-infrared(mid-IR)emissivity of MXene,combined with the densely oriented structure affords the composite films with IR stealth,resulting in a substantial decrease from 150 to 66.1℃in the radiative temperature of a surface.Conclusively,these scalable MXene/PVA films exhibit remarkable potential for integration into the next generation of multifunctional protective camouflage materials.
基金supported by the National Natural Science Foundation of China(22102104 and U22A2064)the General Research Fund(project no.14203123)+7 种基金National Key Research and Development Project(grant no.2023YFB4705300)the Shenzhen Science and Technology Program(JCYJ20220531103409021 and JCYJ20220818101611025)the Guangdong Basic and Applied Basic Research Foundation(2021A1515010672 and 2022B1515120010)the Research Impact Fund(project no.R4015-21)Research Fellow Scheme(project no.RFS2122-4S03)the EU-Hong Kong Research and Innovation Cooperation Co-funding Mechanism(project no.E-CUHK401/20)from the Research Grants Council(RGC)of Hong Kongthe support from the SIATCUHK Joint Laboratory of Robotics and Intelligent Systems and the Multi-Scale Medical Robotics Center(MRC),InnoHK,at the Hong Kong Science ParkGuangdong University Students Science and Technology Innovation Cultivation Special Fund Project with project no.pdjh2022b0446.
文摘Untethered and self-transformable miniature robots are capable of performing reconfigurable deformation and on-demand locomotion,which aid the traversal toward various lumens,and bring revolutionary changes for targeted delivery in gastrointestinal(GI)tract.However,the viscous non-Newtonian liquid environment and plicae gastricae obstacles severely hamper high-precision actuation and payload delivery.Here,we developed a low-friction soft robot by assembly of densely arranged cone structures and grafting of hydrophobic monolayers.The magnetic orientation encoded robot can move in multiple modes,with a substantially reduced drag,terrain adaptability,and improved motion velocity across the non-Newtonian liquids.Notably,the robot stiffness can be reversibly controlled with magnetically induced hardening,enabling on-site scratching and destruction of antibiotic-ineradicable polymeric matrix in biofilms with a low-frequency magnetic field.Furthermore,the magnetocaloric effect can be utilized to eradicate the bacteria by magnetocaloric effect under high-frequency alternating field.To verify the potential applications inside the body,the clinical imaging-guided actuation platforms were developed for vision-based control and delivery of the robots.The developed low-friction robots and clinical imaging-guided actuation platforms show their high potential to perform bacterial infection therapy in various lumens inside the body.
