Transportation structures such as composite pavements and railway foundations typically consist of multi-layered media designed to withstand high bearing capacity.A theoretical understanding of load transfer mechanism...Transportation structures such as composite pavements and railway foundations typically consist of multi-layered media designed to withstand high bearing capacity.A theoretical understanding of load transfer mechanisms in these multi-layer composites is essential,as it offers intuitive insights into parametric influences and facilitates enhanced structural performance.This paper employs an improved transfer matrix method to address the limitations of existing theoretical approaches for analyzing multi-layer composite structures.By establishing a twodimensional composite pavement model,it investigates load transfer characteristics and validates the accuracy through finite element simulation.The proposed method offers a straightforward analytical approach for examining internal interactions between structural layers.Case studies indicate that the concrete surface layer is the main load-bearing layer for most vertical normal and shear stresses.The soil base layer reduces the overall mechanical response of the substructure,while horizontal actions increase the risk of interfacial slip and cracking.Structural optimization analysis demonstrates that increasing the thickness of the concrete surface layer,enhancing the thickness and stiffness of the soil base layer,or incorporating gradient layers can significantly mitigate these risks of interfacial slip and cracking.The findings of this study can guide the optimization design,parameter analysis,and damage prevention of multi-layer composite structures.展开更多
A two-dimensional electromagnetic particle-in-cell simulation model is proposed to study the density evolution and collective stopping of electron beams in background plasmas.We show here the formation of the multi-la...A two-dimensional electromagnetic particle-in-cell simulation model is proposed to study the density evolution and collective stopping of electron beams in background plasmas.We show here the formation of the multi-layer structure of the relativistic electron beam in the plasma due to the different betatron frequency from the beam front to the beam tail.Meanwhile,the nonuniformity of the longitudinal wakefield is the essential reason for the multi-layer structure formation in beam phase space.The influences of beam parameters(beam radius and transverse density profile)on the formation of the multi-layer structure and collective stopping in background plasmas are also considered.展开更多
With the continuous improvement of China's science and technology, the design method of steel structure is also more and more, how to better apply the module building design method to the related buildings, is the...With the continuous improvement of China's science and technology, the design method of steel structure is also more and more, how to better apply the module building design method to the related buildings, is the current issue to focus on consideration. Therefore, this paper will focus on the design method of multi-layer steel structure module and steel frame composite building structure, and analyze and study its structure, so as to improve the utilization rate of steel structure and promote the development of the construction industry.展开更多
This paper introduces the construction of the multi-layered biaxial weft knitted fabric （MBWK fabric） and studies the locking angle of this kind of fabric. Moreover, a locking angle model of the MBWK fabric is estab...This paper introduces the construction of the multi-layered biaxial weft knitted fabric （MBWK fabric） and studies the locking angle of this kind of fabric. Moreover, a locking angle model of the MBWK fabric is established for the first time according to its unique construction. Two kinds of locking angles are considered under different restraint conditions: the locking angle θ1 controlled by the inserting yarns and the locking angle θ2 controlled by the stitch yarns. It is concluded that the ultimate value of the locking angle θ is the larger one of the two angles.展开更多
This study proposes a general imperfect thermal contact model to predict the thermal contact resistance at the interface among multi-layered composite structures.Based on the Green-Lindsay(GL)thermoelastic theory,semi...This study proposes a general imperfect thermal contact model to predict the thermal contact resistance at the interface among multi-layered composite structures.Based on the Green-Lindsay(GL)thermoelastic theory,semi analytical solutions of temperature increment and displacement of multi-layered composite structures are obtained by using the Laplace transform method,upon which the effects of thermal resistance coefficient,partition coefficient,thermal conductivity ratio and heat capacity ratio on the responses are studied.The results show that the generalized imperfect thermal contact model can realistically describe the imperfect thermal contact problem.Accordingly,it may degenerate into other thermal contact models by adjusting the thermal resistance coefficient and partition coefficient.展开更多
In this study,a high impact resistant multi-layered composite consisting of continuous carbon fibre/nylon(CCF)and short carbon fibre/nylon(SCF)layers is developed via 3D printing technology.The effect of CCF/SCF layer...In this study,a high impact resistant multi-layered composite consisting of continuous carbon fibre/nylon(CCF)and short carbon fibre/nylon(SCF)layers is developed via 3D printing technology.The effect of CCF/SCF layers configuration on the impact resistance is investigated by low-velocity impact test,and the impact failure mechanism of the 3D printed composites is explored by microscopic observations and finite element(FE)simulation analysis.The results show that the 3D printed multi-layered composite with SCF layers distributed in the middle(HFA)exhibits higher impact resistant performance than the specimens with alternating SCF/CCF layers(HFB)and CCF layers distributed in the middle(HFC).The effect of CCF/SCF layers proportion on the impact performance is also studied by FE simulation,and the results show that the specimen with a CCF/SCF proportion of 7.0 exhibits the highest impact strength.展开更多
Various nanostructured architectures have been demonstrated to be effective to address the issues of high capacity Si anodes. However, the scale-up of these nano-Si materials is still a critical obstacle for commercia...Various nanostructured architectures have been demonstrated to be effective to address the issues of high capacity Si anodes. However, the scale-up of these nano-Si materials is still a critical obstacle for commercialization. Herein, we use industrial ferrosilicon as low-cost Si source and introduce a facile and scalable method to fabricate a micrometer-sized ferrosilicon/C composite anode, in which ferrosilicon microparticles are wrapped with multi-layered carbon nanosheets. The multi-layered carbon nanosheets could effectively buffer the volume variation of Si as well as create an abundant and reliable conductivity framework, ensuring fast transport of electrons. As a result, the micrometer-sized ferrosilicon/C anode achieves a stable cycling with 805.9 m Ah g-1 over 200 cycles at 500 mA g-1 and a good rate capability of455.6 mAh g-1 at 10 A g-1. Therefore, our approach based on ferrosilicon provides a new opportunity in fabricating cost-effective, pollution-free, and large-scale Si electrode materials for high energy lithium-ion batteries.展开更多
Glass fibre-reinforced(GFR)structure is extensively used in radome,spoiler and some other equipment.In engineering practice,due to the influence of wear,aging,impact,chemical corrosion of surface structure and other f...Glass fibre-reinforced(GFR)structure is extensively used in radome,spoiler and some other equipment.In engineering practice,due to the influence of wear,aging,impact,chemical corrosion of surface structure and other factors,the internal structure of this kind of structure gradually evolves into a defect state and expands to form defects such as bubbles,scratches,shorts,cracks,cavitation erosion,stains and other defects.These defects have posed a serious threat to the quality and performance of GFR structure.From the propagation process of GFR structure defects,its duration is random and may be very short.Therefore,designing a scientific micro defect intelligent detection system for GFR structure to enhance the maintainability of GFR structure will not only help to reduce emergencies,but also have positive theoretical significance and application value to ensure safe production and operation.Firstly,the defect detection mechanism of GFR structure is discussed,and the defect detection principle and defect area identification method are analyzed.Secondly,the processing process of defect edge signal is discussed,a classifier based on MLP is established,and the algorithm of the classifier is designed.Finally,the effectiveness of this method is proved by real-time monitoring and defect diagnosis of a typical GFR structure.The experimental results show that this method improves the efficiency of defect detection and has high defect feature recognition accuracy,which provides a new idea for the on-line detection of GFR structure defects.展开更多
Solar energy has always been a kind of energy with large reserves and wide application.It is well utilized through solar absorbers.In our study,the finite difference time domain method(FDTD)is used to simulate the abs...Solar energy has always been a kind of energy with large reserves and wide application.It is well utilized through solar absorbers.In our study,the finite difference time domain method(FDTD)is used to simulate the absorber composed of refractory metal materials,and its absorption performance and thermal emission performance are obtained.The ultra-wide band of 200 nm-3000 nm reaches 95.93%absorption efficiency,of which the bandwidth absorption efficiency of2533 nm(200 nm-2733 nm)is greater than 90%.The absorption efficiency in the whole spectrum range(200 nm-2733 nm)is 97.17%on average.The multilayer nanodisk structure of the absorber allows it to undergo strong surface plasmon resonance and near-field coupling when irradiated by incident light.The thermal emission performance of the absorber enables it to also be applied to the thermal emitter.The thermal emission efficiency of 95.37%can be achieved at a high temperature of up to 1500 K.Moreover,the changes of polarization and incident angle do not cause significant changes in absorption.Under the gradual change of polarization angle(0°-90°),the absorption spectrum maintains a high degree of consistency.As the incident angle increases from 0°to 60°,there is still 85%absorption efficiency.The high absorption efficiency and excellent thermal radiation intensity of ultra-wideband enable it to be deeply used in energy absorption and conversion applications.展开更多
Stress distribution in the gradient multi-layered surface under a sliding contact was investigated using finite element method(FEM). The main structure parameters of layered surface discussed are total layer thickness...Stress distribution in the gradient multi-layered surface under a sliding contact was investigated using finite element method(FEM). The main structure parameters of layered surface discussed are total layer thickness,layer number and elastic modulus ratio of layer to the substrate. A model of multi-layered surface contact with rough slider was studied. The effect of the surface structure parameters on the elastic-plastic deformation was analyzed.展开更多
A simple model for approximate bandgap structure calculation of all-solid photonic bandgap fibre based on an array of rings is proposed. In this model calculated are only the potential modes of a unit cell, which is a...A simple model for approximate bandgap structure calculation of all-solid photonic bandgap fibre based on an array of rings is proposed. In this model calculated are only the potential modes of a unit cell, which is a high-index ring in the low-index background for this fibre, rather than the whole cladding periodic structure based on Bloch＇s theorem to find the bandgap. Its accuracy is proved by comparing its results with the results obtained by using the accurate full-vector plane-wave method. High speed in computation is its great advantage over the other exact methods, because it only needs to find the roots of one-dimensional analytical expressions. And the results of this model, mode plots, offer an ideal environment to explore the basic properties of photonie bandgap clearly.展开更多
The paper presents the prerequisites of involving of topological elements and graph theory as an instrument of mathematical formalization of woven structures and technology of textile fabrics. Present research is base...The paper presents the prerequisites of involving of topological elements and graph theory as an instrument of mathematical formalization of woven structures and technology of textile fabrics. Present research is based on analysis and comparison of the main concepts and conditions of textile technology and graph theory.展开更多
The Sichuan Basin represents the earliest area where natural gas is explored,developed and comprehensively utilized in China.After over 50 years of oil and gas exploration,oil and gas reservoirs have been discovered i...The Sichuan Basin represents the earliest area where natural gas is explored,developed and comprehensively utilized in China.After over 50 years of oil and gas exploration,oil and gas reservoirs have been discovered in 24 gas-dominant layers in this basin.For the purpose of predicting natural gas exploration direction and target of each layer in the Sichuan Basin,the sedimentary characteristics of marine and continental strata in this basin were summarized and the forms of multi-cycled tectonic movement and their controlling effect on sedimentation,diagenesis and hydrocarbon accumulation were analyzed.Based on the analysis,the following characteristics were identified.First,the Sichuan Basin has experienced the transformation from marine sedimentation to continental sedimentation since the Sinian with the former being dominant.Second,multiple sourceereservoir assemblages are formed based on multi-rhythmed deposition,and multi-layered reservoir hydrocarbon accumulation characteristics are vertically presented.And third,multi-cycled tectonic movement appears in many forms and has a significant controlling effect on sedimentation,diagenesis and hydrocarbon accumulation.Then,oil and gas reservoir characteristics and enrichment laws were investigated.It is indicated that the Sichuan Basin is characterized by coexistence of conventional and unconventional oil and gas reservoirs,multi-layered reservoir hydrocarbon supply,multiple reservoir types,multiple trap types,multi-staged hydrocarbon accumulation and multiple hydrocarbon accumulation models.Besides,its natural gas enrichment is affected by hydrocarbon source intensity,large paleo-uplift,favorable sedimentary facies belt,sedimentaryestructural discontinuity plane and structural fracture development.Finally,the natural gas exploration and research targets of each layer in the Sichuan Basin were predicted according to the basic petroleum geologic conditions,enrichment laws and exploration status.展开更多
Ocean waves present a promising renewable energy resource due to their high energy density,global availability,and significant energy storage capacity.To enhance the efficiency of wave energy harvesting,a novel multi-...Ocean waves present a promising renewable energy resource due to their high energy density,global availability,and significant energy storage capacity.To enhance the efficiency of wave energy harvesting,a novel multi-layered nested continuously rotating triboelectric nanogenerator(MCR-TENG)has been developed.This advanced design incorporates four TENG units arranged to optimize the internal space within a cylindrical tube,coupled with a gear system that synchronizes with both the ascent and descent phases of ocean waves.This configuration effectively converts the up-anddown motion of waves into continuous rotational motion,thus enhancing energy capture capacity.The MCR-TENG demonstrates a peak output power of 70.23 mW and an average output power of 17.52 mW,with a volumetric average power density of 4.49 W·m−3.The device successfully powers various appliances,including commercial navigation lights,water quality detection pens,temperature and humidity sensors,and water immersion alarms,thereby showcasing its substantial load capacity and efficient energy conversion.This study marks a significant advancement in the development of TENG technology for practical wave energy applications,offering improved energy harvesting efficiency and demonstrating its potential for real-world deployment.展开更多
Against the backdrop of China's High-Speed Rail(HSR)network achieving global leadership in scale(48,000 km,70%worldwide)yet facing structural fragility,disaster-chain coupling,and regional imbalance,this study con...Against the backdrop of China's High-Speed Rail(HSR)network achieving global leadership in scale(48,000 km,70%worldwide)yet facing structural fragility,disaster-chain coupling,and regional imbalance,this study constructs a"structural resilience-propagation dynamics-intelligent governance"trinity framework.By integrating multi-layer coupled network theory,this paper develop:(1)A spatiotemporal-weighted betweenness centrality algorithm dynamically identifying critical nodes using Beidou data;(2)A multi-layer SEIR model quantifying epidemic-economic dual diffusion with linear threshold mechanisms;(3)A reinforcement learning framework optimizing anti-siphoning policies.Key findings reveal:Wuhan hub fault recovery time reduced by 50%through backup topology,Beijing West Station achieved 89%epidemic blocking via dual-channel quarantine,and the Chengdu-Chongqing regional Gini coefficient decreased 29%via frequency regulation.The paradigm shift from static planning to real-time adaptive governance offers a"China solution"for global railway resilience,evidenced by magnetic levitation standards(e.g.,18%energy savings in Saudi NEOM line)and multi-disaster defense systems(35%faster ASEAN flood recovery).展开更多
Detachment structures occur widely in the crust, and it is the commonest and most important deformation type developed in the region between orogenic belts and basins. The ＇comb-like＇ and ＇toughlike＇ fold belts in...Detachment structures occur widely in the crust, and it is the commonest and most important deformation type developed in the region between orogenic belts and basins. The ＇comb-like＇ and ＇toughlike＇ fold belts in eastern Sichuan are caused by multi-layer detachment. The duplex structure is the most important deformation style in the region, exhibiting different characteristics from typical detachment structures. Different deformation styles, scales, and shortenings resulting from independent deformations of various detachment systems would lead to the phenomenon whereby most of the topographical heights in the region do not correspond to the structural heights in depth. Based on systematic structural analysis and combined with practical oil/gas prospecting, four types of structural traps are described from eastern Sichuan Province, which are： detachment and thrust trap; detachment folding trap; fault-flat blocking trap; and detachment layer trap. Meticulous studies on the deformation and distribution of detachment layers in the eastern Sichuan Province will contribute to oil/gas prospecting and selection of potential regions of marine-origin oil/gas prospecting in South China.展开更多
Weft knitted fancy fabrics are widely used in knitted garment design. Due to the complexity of the structures, their modeling and simulation needs to be solved in three-dimensional (3D) CAD developments. In this paper...Weft knitted fancy fabrics are widely used in knitted garment design. Due to the complexity of the structures, their modeling and simulation needs to be solved in three-dimensional (3D) CAD developments. In this paper, 3D loop geometrical models of weft knitted fancy structures, including tuck stitch, jacquard stitch, transfer stitch and fleecy stitch, were developed based on an improved model of plain loop, and their central axes as some 3D space curves were achieved by using Non-Uniform Rational B-Splines (NURBS). The 3D visual simulation programme was written in C++ programming language using OpenGL, which was a function library of 3D graphics. Some examples of weft knitted fancy fabrics were generated and practical application of 3D simulation was discussed.展开更多
Heat conduction in multi-layer and composite materials is one of the fundamental heat transfer problems in many industrial applications.Due to different materials types,interface conditions,and various geometries of t...Heat conduction in multi-layer and composite materials is one of the fundamental heat transfer problems in many industrial applications.Due to different materials types,interface conditions,and various geometries of these laminates,the heat conduction mechanism is more complicated than that of one-layer isotropic media.Analytical solutions are the best ways to study and understand such problems in depth.In this study,different existing analytical solutions for heat conduction in multi-layer and composite materials are reviewed and classified in rectangular,cylindrical,spherical,and conical coordinates.Applied boundary conditions,internal heat source,and thermal contact resistance as the most critical parameters in the solution complexity investigated in the literature,are discussed and summarized in different tables.Various types of multi-layer structures such as isotropic,anisotropic,orthotropic,and reinforced laminates are included in this study.It is found that although more than half a century has passed since the beginning of the research on heat transfer in multi-layer composites,new researches that can help with a better understanding in this area are still being offered.The challenges and shortcomings in this area are also discussed to guide future researches.展开更多
A better understanding of the mechanical behavior of the multilayered structure under extermal loading is the most important item for the structural design and the risk asssment.The objective of this study are to prop...A better understanding of the mechanical behavior of the multilayered structure under extermal loading is the most important item for the structural design and the risk asssment.The objective of this study are to propose and develop an analytical solution for the mechanical behaviors of multi-layered structure generated by axisy mmetric loading,and to investigate the impact of anisotropic layers and interlayer conditions on the multi-layered structure.To reach these objectives,first,according to the goveming equations,the analytical solution for a single layer was formulated by adopting the spatial Hankel transform.Then the global matrix technique is applied to achieve the analytical solution of multi-layered structure in Hankel domain.The sliding and bonded interlayer conditions were considered in this process.Finally,the numerical inversion of integral transform was used to solve the components of displacement and stress in real domain.Gauss-Lcgendre quadrature is a key scheme in the numerical inversion process.Moreover,following by the verification of the proposed analytical solution,one typical three-layered flexible pavement was applied as the computing carrier of numerical analysis for the multi-layered structure.The results have shown that the anisotropic layers and the interlayer conditions significantly affect the mechanical behaviors of the proposed structure.展开更多
基金supported by Fundamental Research Funds for the Central Universities(No.lzujbky-2024-05)Innovation Foundation of Provincial Education Department of Gansu(2024B-005)+2 种基金Scientific Department of Gansu(24CXGA083,24CXGA024,JK2024-28,JK2024-32 and 23CXJA0007)Industrial Support Plan Project of Provincial Education Department of Gansu(2025CYZC-003 and CYZC-2024-10)the Hunan Natural Science Foundation Science and Education Joint Fund Project(2022JJ60109).
文摘Transportation structures such as composite pavements and railway foundations typically consist of multi-layered media designed to withstand high bearing capacity.A theoretical understanding of load transfer mechanisms in these multi-layer composites is essential,as it offers intuitive insights into parametric influences and facilitates enhanced structural performance.This paper employs an improved transfer matrix method to address the limitations of existing theoretical approaches for analyzing multi-layer composite structures.By establishing a twodimensional composite pavement model,it investigates load transfer characteristics and validates the accuracy through finite element simulation.The proposed method offers a straightforward analytical approach for examining internal interactions between structural layers.Case studies indicate that the concrete surface layer is the main load-bearing layer for most vertical normal and shear stresses.The soil base layer reduces the overall mechanical response of the substructure,while horizontal actions increase the risk of interfacial slip and cracking.Structural optimization analysis demonstrates that increasing the thickness of the concrete surface layer,enhancing the thickness and stiffness of the soil base layer,or incorporating gradient layers can significantly mitigate these risks of interfacial slip and cracking.The findings of this study can guide the optimization design,parameter analysis,and damage prevention of multi-layer composite structures.
基金supported by National Natural Science Foundation of China(Nos.12075046 and 11775042)。
文摘A two-dimensional electromagnetic particle-in-cell simulation model is proposed to study the density evolution and collective stopping of electron beams in background plasmas.We show here the formation of the multi-layer structure of the relativistic electron beam in the plasma due to the different betatron frequency from the beam front to the beam tail.Meanwhile,the nonuniformity of the longitudinal wakefield is the essential reason for the multi-layer structure formation in beam phase space.The influences of beam parameters(beam radius and transverse density profile)on the formation of the multi-layer structure and collective stopping in background plasmas are also considered.
文摘With the continuous improvement of China's science and technology, the design method of steel structure is also more and more, how to better apply the module building design method to the related buildings, is the current issue to focus on consideration. Therefore, this paper will focus on the design method of multi-layer steel structure module and steel frame composite building structure, and analyze and study its structure, so as to improve the utilization rate of steel structure and promote the development of the construction industry.
文摘This paper introduces the construction of the multi-layered biaxial weft knitted fabric （MBWK fabric） and studies the locking angle of this kind of fabric. Moreover, a locking angle model of the MBWK fabric is established for the first time according to its unique construction. Two kinds of locking angles are considered under different restraint conditions: the locking angle θ1 controlled by the inserting yarns and the locking angle θ2 controlled by the stitch yarns. It is concluded that the ultimate value of the locking angle θ is the larger one of the two angles.
基金Projects(42477162,52108347,52178371,52168046,52178321,52308383)supported by the National Natural Science Foundation of ChinaProjects(2023C03143,2022C01099,2024C01219,2022C03151)supported by the Zhejiang Key Research and Development Plan,China+6 种基金Project(LQ22E080010)supported by the Exploring Youth Project of Zhejiang Natural Science Foundation,ChinaProject(LR21E080005)supported by the Outstanding Youth Project of Natural Science Foundation of Zhejiang Province,ChinaProject(2022M712964)supported by the Postdoctoral Science Foundation of ChinaProject(2023AFB008)supported by the Natural Science Foundation of Hubei Province for Youth,ChinaProject(202203)supported by Engineering Research Centre of Rock-Soil Drilling&Excavation and Protection,Ministry of Education,ChinaProject(202305-2)supported by the Science and Technology Project of Zhejiang Provincial Communication Department,ChinaProject(2021K256)supported by the Construction Research Founds of Department of Housing and Urban-Rural Development of Zhejiang Province,China。
文摘This study proposes a general imperfect thermal contact model to predict the thermal contact resistance at the interface among multi-layered composite structures.Based on the Green-Lindsay(GL)thermoelastic theory,semi analytical solutions of temperature increment and displacement of multi-layered composite structures are obtained by using the Laplace transform method,upon which the effects of thermal resistance coefficient,partition coefficient,thermal conductivity ratio and heat capacity ratio on the responses are studied.The results show that the generalized imperfect thermal contact model can realistically describe the imperfect thermal contact problem.Accordingly,it may degenerate into other thermal contact models by adjusting the thermal resistance coefficient and partition coefficient.
基金This work was supported by the National Science Fund for Distinguished Young Scholars(Grant No.11625210)the National Science Foundation of China(Grant No.51873153)+1 种基金the Shanghai Pujiang Program(Grant No.19PJ1410000)the Shanghai International Science and Technology Cooperation Fund Project(Grant No.19520713000).
文摘In this study,a high impact resistant multi-layered composite consisting of continuous carbon fibre/nylon(CCF)and short carbon fibre/nylon(SCF)layers is developed via 3D printing technology.The effect of CCF/SCF layers configuration on the impact resistance is investigated by low-velocity impact test,and the impact failure mechanism of the 3D printed composites is explored by microscopic observations and finite element(FE)simulation analysis.The results show that the 3D printed multi-layered composite with SCF layers distributed in the middle(HFA)exhibits higher impact resistant performance than the specimens with alternating SCF/CCF layers(HFB)and CCF layers distributed in the middle(HFC).The effect of CCF/SCF layers proportion on the impact performance is also studied by FE simulation,and the results show that the specimen with a CCF/SCF proportion of 7.0 exhibits the highest impact strength.
基金the National Natural Science Foundation of China(No:21703285)。
文摘Various nanostructured architectures have been demonstrated to be effective to address the issues of high capacity Si anodes. However, the scale-up of these nano-Si materials is still a critical obstacle for commercialization. Herein, we use industrial ferrosilicon as low-cost Si source and introduce a facile and scalable method to fabricate a micrometer-sized ferrosilicon/C composite anode, in which ferrosilicon microparticles are wrapped with multi-layered carbon nanosheets. The multi-layered carbon nanosheets could effectively buffer the volume variation of Si as well as create an abundant and reliable conductivity framework, ensuring fast transport of electrons. As a result, the micrometer-sized ferrosilicon/C anode achieves a stable cycling with 805.9 m Ah g-1 over 200 cycles at 500 mA g-1 and a good rate capability of455.6 mAh g-1 at 10 A g-1. Therefore, our approach based on ferrosilicon provides a new opportunity in fabricating cost-effective, pollution-free, and large-scale Si electrode materials for high energy lithium-ion batteries.
基金Guangdong Provincial University Key Special Project Fund(No.2020zdzx2032)National Entrepreneurship Practice Fund(No.202013684009s)。
文摘Glass fibre-reinforced(GFR)structure is extensively used in radome,spoiler and some other equipment.In engineering practice,due to the influence of wear,aging,impact,chemical corrosion of surface structure and other factors,the internal structure of this kind of structure gradually evolves into a defect state and expands to form defects such as bubbles,scratches,shorts,cracks,cavitation erosion,stains and other defects.These defects have posed a serious threat to the quality and performance of GFR structure.From the propagation process of GFR structure defects,its duration is random and may be very short.Therefore,designing a scientific micro defect intelligent detection system for GFR structure to enhance the maintainability of GFR structure will not only help to reduce emergencies,but also have positive theoretical significance and application value to ensure safe production and operation.Firstly,the defect detection mechanism of GFR structure is discussed,and the defect detection principle and defect area identification method are analyzed.Secondly,the processing process of defect edge signal is discussed,a classifier based on MLP is established,and the algorithm of the classifier is designed.Finally,the effectiveness of this method is proved by real-time monitoring and defect diagnosis of a typical GFR structure.The experimental results show that this method improves the efficiency of defect detection and has high defect feature recognition accuracy,which provides a new idea for the on-line detection of GFR structure defects.
基金support from the National Natural Science Foundation of China (Grant No.51606158,11604311,12074151)the Guangxi Science and Technology Base and Talent Special Project (Grant No.AD21075009)+6 种基金the Sichuan Science and Technology Program (Grant No.2021JDRC0022)the Natural Science Foundation of Fujian Province (Grant No.2021J05202)the Research Project of Fashu Foundation (Grant No.MFK23006)the Open Fund of the Key Laboratory for Metallurgical Equipment and Control Technology of Ministry of Education in Wuhan University of Science and Technology,China (Grant No.MECOF2022B01MECOF2023B04)the Project supported by Guangxi Key Laboratory of Precision Navigation Technology and Application,Guilin University of Electronic Technology (Grant No.DH202321)the Scientific Research Project of Huzhou College (Grant No.2022HXKM07)。
文摘Solar energy has always been a kind of energy with large reserves and wide application.It is well utilized through solar absorbers.In our study,the finite difference time domain method(FDTD)is used to simulate the absorber composed of refractory metal materials,and its absorption performance and thermal emission performance are obtained.The ultra-wide band of 200 nm-3000 nm reaches 95.93%absorption efficiency,of which the bandwidth absorption efficiency of2533 nm(200 nm-2733 nm)is greater than 90%.The absorption efficiency in the whole spectrum range(200 nm-2733 nm)is 97.17%on average.The multilayer nanodisk structure of the absorber allows it to undergo strong surface plasmon resonance and near-field coupling when irradiated by incident light.The thermal emission performance of the absorber enables it to also be applied to the thermal emitter.The thermal emission efficiency of 95.37%can be achieved at a high temperature of up to 1500 K.Moreover,the changes of polarization and incident angle do not cause significant changes in absorption.Under the gradual change of polarization angle(0°-90°),the absorption spectrum maintains a high degree of consistency.As the incident angle increases from 0°to 60°,there is still 85%absorption efficiency.The high absorption efficiency and excellent thermal radiation intensity of ultra-wideband enable it to be deeply used in energy absorption and conversion applications.
基金Project(50071014) supported by the National Natural Science Foundation of China
文摘Stress distribution in the gradient multi-layered surface under a sliding contact was investigated using finite element method(FEM). The main structure parameters of layered surface discussed are total layer thickness,layer number and elastic modulus ratio of layer to the substrate. A model of multi-layered surface contact with rough slider was studied. The effect of the surface structure parameters on the elastic-plastic deformation was analyzed.
基金Project supported by the National High Technology Research and Development Program of China (Grant No 2004AA31G200)Beijing Jiaotong University Foundation, China (Grant No 2005SM002)
文摘A simple model for approximate bandgap structure calculation of all-solid photonic bandgap fibre based on an array of rings is proposed. In this model calculated are only the potential modes of a unit cell, which is a high-index ring in the low-index background for this fibre, rather than the whole cladding periodic structure based on Bloch＇s theorem to find the bandgap. Its accuracy is proved by comparing its results with the results obtained by using the accurate full-vector plane-wave method. High speed in computation is its great advantage over the other exact methods, because it only needs to find the roots of one-dimensional analytical expressions. And the results of this model, mode plots, offer an ideal environment to explore the basic properties of photonie bandgap clearly.
文摘The paper presents the prerequisites of involving of topological elements and graph theory as an instrument of mathematical formalization of woven structures and technology of textile fabrics. Present research is based on analysis and comparison of the main concepts and conditions of textile technology and graph theory.
文摘The Sichuan Basin represents the earliest area where natural gas is explored,developed and comprehensively utilized in China.After over 50 years of oil and gas exploration,oil and gas reservoirs have been discovered in 24 gas-dominant layers in this basin.For the purpose of predicting natural gas exploration direction and target of each layer in the Sichuan Basin,the sedimentary characteristics of marine and continental strata in this basin were summarized and the forms of multi-cycled tectonic movement and their controlling effect on sedimentation,diagenesis and hydrocarbon accumulation were analyzed.Based on the analysis,the following characteristics were identified.First,the Sichuan Basin has experienced the transformation from marine sedimentation to continental sedimentation since the Sinian with the former being dominant.Second,multiple sourceereservoir assemblages are formed based on multi-rhythmed deposition,and multi-layered reservoir hydrocarbon accumulation characteristics are vertically presented.And third,multi-cycled tectonic movement appears in many forms and has a significant controlling effect on sedimentation,diagenesis and hydrocarbon accumulation.Then,oil and gas reservoir characteristics and enrichment laws were investigated.It is indicated that the Sichuan Basin is characterized by coexistence of conventional and unconventional oil and gas reservoirs,multi-layered reservoir hydrocarbon supply,multiple reservoir types,multiple trap types,multi-staged hydrocarbon accumulation and multiple hydrocarbon accumulation models.Besides,its natural gas enrichment is affected by hydrocarbon source intensity,large paleo-uplift,favorable sedimentary facies belt,sedimentaryestructural discontinuity plane and structural fracture development.Finally,the natural gas exploration and research targets of each layer in the Sichuan Basin were predicted according to the basic petroleum geologic conditions,enrichment laws and exploration status.
基金supported by the National Key Research&Development Program of China(Nos.2021YFA1201604 and 2021YFA1201601)the National Natural Science Foundation of China(No.52472190)+1 种基金Beijing Natural Science Foundation(No.L245021)Beijing Nova Program(Nos.20220484036 and 20240484565).
文摘Ocean waves present a promising renewable energy resource due to their high energy density,global availability,and significant energy storage capacity.To enhance the efficiency of wave energy harvesting,a novel multi-layered nested continuously rotating triboelectric nanogenerator(MCR-TENG)has been developed.This advanced design incorporates four TENG units arranged to optimize the internal space within a cylindrical tube,coupled with a gear system that synchronizes with both the ascent and descent phases of ocean waves.This configuration effectively converts the up-anddown motion of waves into continuous rotational motion,thus enhancing energy capture capacity.The MCR-TENG demonstrates a peak output power of 70.23 mW and an average output power of 17.52 mW,with a volumetric average power density of 4.49 W·m−3.The device successfully powers various appliances,including commercial navigation lights,water quality detection pens,temperature and humidity sensors,and water immersion alarms,thereby showcasing its substantial load capacity and efficient energy conversion.This study marks a significant advancement in the development of TENG technology for practical wave energy applications,offering improved energy harvesting efficiency and demonstrating its potential for real-world deployment.
文摘Against the backdrop of China's High-Speed Rail(HSR)network achieving global leadership in scale(48,000 km,70%worldwide)yet facing structural fragility,disaster-chain coupling,and regional imbalance,this study constructs a"structural resilience-propagation dynamics-intelligent governance"trinity framework.By integrating multi-layer coupled network theory,this paper develop:(1)A spatiotemporal-weighted betweenness centrality algorithm dynamically identifying critical nodes using Beidou data;(2)A multi-layer SEIR model quantifying epidemic-economic dual diffusion with linear threshold mechanisms;(3)A reinforcement learning framework optimizing anti-siphoning policies.Key findings reveal:Wuhan hub fault recovery time reduced by 50%through backup topology,Beijing West Station achieved 89%epidemic blocking via dual-channel quarantine,and the Chengdu-Chongqing regional Gini coefficient decreased 29%via frequency regulation.The paradigm shift from static planning to real-time adaptive governance offers a"China solution"for global railway resilience,evidenced by magnetic levitation standards(e.g.,18%energy savings in Saudi NEOM line)and multi-disaster defense systems(35%faster ASEAN flood recovery).
基金funded by the Science and Technology Research and Development Program of the China Petroleum & Chemical Corporation(No.P06088)the Nonprofit Special Research Program(No.200811015)the Land Resource Survey Project of the Ministry of Land and Natural Resources,China(No.1212010782003)
文摘Detachment structures occur widely in the crust, and it is the commonest and most important deformation type developed in the region between orogenic belts and basins. The ＇comb-like＇ and ＇toughlike＇ fold belts in eastern Sichuan are caused by multi-layer detachment. The duplex structure is the most important deformation style in the region, exhibiting different characteristics from typical detachment structures. Different deformation styles, scales, and shortenings resulting from independent deformations of various detachment systems would lead to the phenomenon whereby most of the topographical heights in the region do not correspond to the structural heights in depth. Based on systematic structural analysis and combined with practical oil/gas prospecting, four types of structural traps are described from eastern Sichuan Province, which are： detachment and thrust trap; detachment folding trap; fault-flat blocking trap; and detachment layer trap. Meticulous studies on the deformation and distribution of detachment layers in the eastern Sichuan Province will contribute to oil/gas prospecting and selection of potential regions of marine-origin oil/gas prospecting in South China.
基金Natural Science Foundation of Tianjin,China( No. 11JCYBJC26400) Tianjin High School Scientific and Technology Fund Planning Project,China( No. 20100310)
文摘Weft knitted fancy fabrics are widely used in knitted garment design. Due to the complexity of the structures, their modeling and simulation needs to be solved in three-dimensional (3D) CAD developments. In this paper, 3D loop geometrical models of weft knitted fancy structures, including tuck stitch, jacquard stitch, transfer stitch and fleecy stitch, were developed based on an improved model of plain loop, and their central axes as some 3D space curves were achieved by using Non-Uniform Rational B-Splines (NURBS). The 3D visual simulation programme was written in C++ programming language using OpenGL, which was a function library of 3D graphics. Some examples of weft knitted fancy fabrics were generated and practical application of 3D simulation was discussed.
基金financial support of the National Natural Science Foundation of China(No.52025061 and No.51961130386)the financial support from the Royal Society-Newton Advanced Fellowship grant(NAF\R1\191163).
文摘Heat conduction in multi-layer and composite materials is one of the fundamental heat transfer problems in many industrial applications.Due to different materials types,interface conditions,and various geometries of these laminates,the heat conduction mechanism is more complicated than that of one-layer isotropic media.Analytical solutions are the best ways to study and understand such problems in depth.In this study,different existing analytical solutions for heat conduction in multi-layer and composite materials are reviewed and classified in rectangular,cylindrical,spherical,and conical coordinates.Applied boundary conditions,internal heat source,and thermal contact resistance as the most critical parameters in the solution complexity investigated in the literature,are discussed and summarized in different tables.Various types of multi-layer structures such as isotropic,anisotropic,orthotropic,and reinforced laminates are included in this study.It is found that although more than half a century has passed since the beginning of the research on heat transfer in multi-layer composites,new researches that can help with a better understanding in this area are still being offered.The challenges and shortcomings in this area are also discussed to guide future researches.
基金This study was funded by the National Natural Science Foundation of China(Grant Nos:51278188,50808077,and 51778224)Project of Young Core Instructor Growth from Hunan Province of Chinathe financial support from the China Scholarship Council(CSC)under No.201606130003
文摘A better understanding of the mechanical behavior of the multilayered structure under extermal loading is the most important item for the structural design and the risk asssment.The objective of this study are to propose and develop an analytical solution for the mechanical behaviors of multi-layered structure generated by axisy mmetric loading,and to investigate the impact of anisotropic layers and interlayer conditions on the multi-layered structure.To reach these objectives,first,according to the goveming equations,the analytical solution for a single layer was formulated by adopting the spatial Hankel transform.Then the global matrix technique is applied to achieve the analytical solution of multi-layered structure in Hankel domain.The sliding and bonded interlayer conditions were considered in this process.Finally,the numerical inversion of integral transform was used to solve the components of displacement and stress in real domain.Gauss-Lcgendre quadrature is a key scheme in the numerical inversion process.Moreover,following by the verification of the proposed analytical solution,one typical three-layered flexible pavement was applied as the computing carrier of numerical analysis for the multi-layered structure.The results have shown that the anisotropic layers and the interlayer conditions significantly affect the mechanical behaviors of the proposed structure.
