A structured method to generate conformal finite element(FE)mesh for realistic 3D woven textile reinforced composite is proposed.It is based on a voxel structure mesh reconstruction framework and aims to provide accur...A structured method to generate conformal finite element(FE)mesh for realistic 3D woven textile reinforced composite is proposed.It is based on a voxel structure mesh reconstruction framework and aims to provide accurate composite model at yarn level with material properties ready for use in commercial FE software.The textile representative volume element(RVE)is generated at filament level implementing the digital element method.Yarn structure is determined by filament bundle with variant cross-section shapes along its path.Yarn surface is then extracted using the Delaunay triangulation algorithm and a surface mesh is initiated.Then,the mesh domain is defined and constructed by voxel structure.Periodic boundary conditions,inter-yarn,and yarnmatrix interfaces are eliminated by re-mesh and mesh optimization.An element splitting rule is established to split the voxel unit into sub-elements to create smooth interface.A 3D orthogonal weave fabric reinforced composite is generated and simulated under compressive load.The composite structure and damage morphology are in good agreement with those of the experiment.展开更多
Urban mountain parks(UMPs)are vital green spaces for public leisure and recreation,but their recreational value is often underdeveloped,with few studies examining the influencing mechanisms of UMP recreational attract...Urban mountain parks(UMPs)are vital green spaces for public leisure and recreation,but their recreational value is often underdeveloped,with few studies examining the influencing mechanisms of UMP recreational attractiveness.To address this issue,this study conducted an empirical investigation in Fuzhou,China.Guided by China’s Standard of Rating for Quality of Tourist Attractions,a structural equation model(SEM)of UMP recreational attractiveness was established and tested based on an expert group and a questionnaire survey of 609 tourists.The findings reveal that seven factors-tourism transport,excursion services,tourism safety,integrated management,natural resource conservation,landscape resource value,and market impact-contribute positively to enhancing UMP recreational attractiveness.Among them,natural resource conservation has the highest influence,followed by landscape resource value,indicating that they both play the greatest role in affecting UMP recreational attractiveness.These seven factors are interrelated,with natural resource conservation strongly positively influencing market impact and landscape resource value.This study explored the influencing mechanism of these seven factors on UMP recreational attractiveness,which can provide practical recommendations for enhancing UMP recreational value worldwide.展开更多
In the rotor system of aero-engines,the main purpose of a bolted flange connection structure is to transfer torque and speed,and the rotor system may exhibit bolt loosening and connection structure failure under compl...In the rotor system of aero-engines,the main purpose of a bolted flange connection structure is to transfer torque and speed,and the rotor system may exhibit bolt loosening and connection structure failure under complex working conditions,high speed rotation,and external excitation unbalanced force.In addition,the bolted connection structure in the rotor system is mainly subjected to torsional vibration excitation,and using experimental methods to analyze the dynamic response law of different structural parameters of a bolted connection structure under torsional vibration excitation is complicated.Therefore,on the basis of the concentrated mass method and the elastic interaction characteristics within the bolted system,this study establishes dynamic models of one-bolted and multi-bolted connection structural systems under torsional excitation.On the basis of this dynamic model,the dynamic response characteristics of different thread parameters,external excitation,bolt stiffness,and compression stiffness of the connected parts in a one-bolted connection system and the influence laws of different elastic modulus,bolt numbers,and the thickness of the connected parts on the loosening of the multi-bolted connection system are analyzed.Results show that small thread pitch,external excitation amplitude and frequency,compressive stiffness,bolt stiffness,and elastic modulus and large tooth angle,number of bolts,and thickness of connected parts can appropriately improve the anti-loosening performance of the bolted connection system.This study also uses a comparative verification method combining finite element simulation and experiment to verify the correctness of the established dynamic model effectively.展开更多
Antimicrobial resistance(AMR)represents a substantial threat to global public health,complicating the treatment of common infections and leading to prolonged illness and escalated healthcare expenses.To effectively co...Antimicrobial resistance(AMR)represents a substantial threat to global public health,complicating the treatment of common infections and leading to prolonged illness and escalated healthcare expenses.To effectively combat AMR,timely and accurate detection is crucial for AMR surveillance and individual-based therapy.Phenotypic antibiotic resistance testing(AST)has long been considered the gold standard in clinical applications,serving as the foundation for clinical AMR diagnosis and optimized therapy.It has significantly contributed to ensuring patients′health and the development of novel antimicrobials.Despite advancements in automated culture-based AST technologies,inherent limitations impede the widespread use of phenotypic AST in AMR surveillance.Genotypic AST technologies offer a promising alternative option,exhibiting advantages of rapidity,high sensitivity,and specificity.With the continuous advancement and expanding applications of genotypic AST technologies,such as microfluidics,mass spectrometry,and high-resolution melting curve analysis,new vigor has been injected into the development and clinical implementation of genotypic AST technologies.In this narrative review,we discuss the principles,applications,and advancements of emerging genotypic AST methods in clinical settings.The comprehensive review aims to highlight the significant scientific potential of emerging genotypic AST technologies in clinical AMR diagnosis,providing insights to enhance existing methods and explore novel approaches.展开更多
基金co-supported by the Chongqing Natural Science Foundation General Project,China(No.CSTB2022NSCQ-MSX1115)。
文摘A structured method to generate conformal finite element(FE)mesh for realistic 3D woven textile reinforced composite is proposed.It is based on a voxel structure mesh reconstruction framework and aims to provide accurate composite model at yarn level with material properties ready for use in commercial FE software.The textile representative volume element(RVE)is generated at filament level implementing the digital element method.Yarn structure is determined by filament bundle with variant cross-section shapes along its path.Yarn surface is then extracted using the Delaunay triangulation algorithm and a surface mesh is initiated.Then,the mesh domain is defined and constructed by voxel structure.Periodic boundary conditions,inter-yarn,and yarnmatrix interfaces are eliminated by re-mesh and mesh optimization.An element splitting rule is established to split the voxel unit into sub-elements to create smooth interface.A 3D orthogonal weave fabric reinforced composite is generated and simulated under compressive load.The composite structure and damage morphology are in good agreement with those of the experiment.
文摘Urban mountain parks(UMPs)are vital green spaces for public leisure and recreation,but their recreational value is often underdeveloped,with few studies examining the influencing mechanisms of UMP recreational attractiveness.To address this issue,this study conducted an empirical investigation in Fuzhou,China.Guided by China’s Standard of Rating for Quality of Tourist Attractions,a structural equation model(SEM)of UMP recreational attractiveness was established and tested based on an expert group and a questionnaire survey of 609 tourists.The findings reveal that seven factors-tourism transport,excursion services,tourism safety,integrated management,natural resource conservation,landscape resource value,and market impact-contribute positively to enhancing UMP recreational attractiveness.Among them,natural resource conservation has the highest influence,followed by landscape resource value,indicating that they both play the greatest role in affecting UMP recreational attractiveness.These seven factors are interrelated,with natural resource conservation strongly positively influencing market impact and landscape resource value.This study explored the influencing mechanism of these seven factors on UMP recreational attractiveness,which can provide practical recommendations for enhancing UMP recreational value worldwide.
基金the financial support of the National Natural Science Foundation of China(NSFC)(Grant No.52375113)the Natural Science Foundation of Liaoning Province of China(Grant No.2022-MS-298)+1 种基金Shenyang Youth Science and Technology Innovation Talent Fund,China(Grant No.RC230309)the Scientific Research Fund of Liaoning Education Department,China(Grant No.LJKMZ20220531).
文摘In the rotor system of aero-engines,the main purpose of a bolted flange connection structure is to transfer torque and speed,and the rotor system may exhibit bolt loosening and connection structure failure under complex working conditions,high speed rotation,and external excitation unbalanced force.In addition,the bolted connection structure in the rotor system is mainly subjected to torsional vibration excitation,and using experimental methods to analyze the dynamic response law of different structural parameters of a bolted connection structure under torsional vibration excitation is complicated.Therefore,on the basis of the concentrated mass method and the elastic interaction characteristics within the bolted system,this study establishes dynamic models of one-bolted and multi-bolted connection structural systems under torsional excitation.On the basis of this dynamic model,the dynamic response characteristics of different thread parameters,external excitation,bolt stiffness,and compression stiffness of the connected parts in a one-bolted connection system and the influence laws of different elastic modulus,bolt numbers,and the thickness of the connected parts on the loosening of the multi-bolted connection system are analyzed.Results show that small thread pitch,external excitation amplitude and frequency,compressive stiffness,bolt stiffness,and elastic modulus and large tooth angle,number of bolts,and thickness of connected parts can appropriately improve the anti-loosening performance of the bolted connection system.This study also uses a comparative verification method combining finite element simulation and experiment to verify the correctness of the established dynamic model effectively.
基金supported by the Non-profit Central Research Institute Fund of Chinese Academy of Medical Sciences(2023-PT310-04)。
文摘Antimicrobial resistance(AMR)represents a substantial threat to global public health,complicating the treatment of common infections and leading to prolonged illness and escalated healthcare expenses.To effectively combat AMR,timely and accurate detection is crucial for AMR surveillance and individual-based therapy.Phenotypic antibiotic resistance testing(AST)has long been considered the gold standard in clinical applications,serving as the foundation for clinical AMR diagnosis and optimized therapy.It has significantly contributed to ensuring patients′health and the development of novel antimicrobials.Despite advancements in automated culture-based AST technologies,inherent limitations impede the widespread use of phenotypic AST in AMR surveillance.Genotypic AST technologies offer a promising alternative option,exhibiting advantages of rapidity,high sensitivity,and specificity.With the continuous advancement and expanding applications of genotypic AST technologies,such as microfluidics,mass spectrometry,and high-resolution melting curve analysis,new vigor has been injected into the development and clinical implementation of genotypic AST technologies.In this narrative review,we discuss the principles,applications,and advancements of emerging genotypic AST methods in clinical settings.The comprehensive review aims to highlight the significant scientific potential of emerging genotypic AST technologies in clinical AMR diagnosis,providing insights to enhance existing methods and explore novel approaches.
