In bio-inspired flapping-wing flight,lift generation and flexible deformation are intrinsically coupled.Thus,an experimental study is conducted to reveal the fluid-structure interaction mechanism for a flexible plate ...In bio-inspired flapping-wing flight,lift generation and flexible deformation are intrinsically coupled.Thus,an experimental study is conducted to reveal the fluid-structure interaction mechanism for a flexible plate undergoing pitching and plunging motion,and theoretical models are proposed to predict either lift or deformation based on a series of simplifying assumptions.It is indicated that flexible plates can effectively reduce the amplitude of lift and pitching moment coefficients during dynamic stall,with increased flexibility leading to higher load reduction.To investigate the effect of plate flexibility on lift,a definition of effective angle of attack is proposed,incorporating the pitching and plunging motion and chordwise deformation of the flexible plate,which can reduce the hysteresis effect of the lift coefficient during dynamic stall.As a consequence,a theoretical model is developed to predict lift based on observed motion and deformation.On the other hand,another theoretical model is developed to predict flexible-plate deformation utilizing aerodynamic forces,revealing the effect of leading-edge vortex evolution on passive deformation.The influence of kinematic parameters,including the maximum effective angle of attack,reduced frequency,and Strouhal number,on the aerodynamic forces is further studied.Compared with the rigid plate,flexible plates exhibit lower sensitivity of aerodynamic forces to changes in kinematic parameters due to their inherent compliance and resulting deformation.The proposed theoretical models can serve as a reference for aerodynamic and deformation prediction in bio-inspired flexible structures.展开更多
Recycling of waste rubber(WR)is crucial for the sustainable development of the rubber industry.The enhancement of interfacial interactions is the main strategy for waste polymer recycling.However,there is a lack of me...Recycling of waste rubber(WR)is crucial for the sustainable development of the rubber industry.The enhancement of interfacial interactions is the main strategy for waste polymer recycling.However,there is a lack of methods for enhancing the interfacial interactions for WR recycling because WR contains abundant inert C―H bonds.Herein,we designed thioctic acid inverse vulcanization copolymers to endow recycled WR with dynamic disulfide interfacial interactions,significantly improving the mechanical properties of recycled WR.These disulfide interfacial interactions among the recycled WR tend to exchange,which dramatically increases the fractocohesive length and prevents stress concentration near the crack tips.When recycled WR is subjected to external stress,the loads are redistributed across a broad region of adjacent regions instead of being concentrated on a limited length scale,which resists crack propagation.This work effectively recycled WR,providing a strategy for solvent-free reaction-derived inverse vulcanization copolymers to improve the toughness of WR recycling.展开更多
Reliable traffic flow prediction is crucial for mitigating urban congestion.This paper proposes Attentionbased spatiotemporal Interactive Dynamic Graph Convolutional Network(AIDGCN),a novel architecture integrating In...Reliable traffic flow prediction is crucial for mitigating urban congestion.This paper proposes Attentionbased spatiotemporal Interactive Dynamic Graph Convolutional Network(AIDGCN),a novel architecture integrating Interactive Dynamic Graph Convolution Network(IDGCN)with Temporal Multi-Head Trend-Aware Attention.Its core innovation lies in IDGCN,which uniquely splits sequences into symmetric intervals for interactive feature sharing via dynamic graphs,and a novel attention mechanism incorporating convolutional operations to capture essential local traffic trends—addressing a critical gap in standard attention for continuous data.For 15-and 60-min forecasting on METR-LA,AIDGCN achieves MAEs of 0.75%and 0.39%,and RMSEs of 1.32%and 0.14%,respectively.In the 60-min long-term forecasting of the PEMS-BAY dataset,the AIDGCN out-performs the MRA-BGCN method by 6.28%,4.93%,and 7.17%in terms of MAE,RMSE,and MAPE,respectively.Experimental results demonstrate the superiority of our pro-posed model over state-of-the-art methods.展开更多
Rockbursts, which mainly affect mining roadways, are dynamic disasters arising from the surrounding rock under high stress. Understanding the interaction between supports and the surrounding rock is necessary for effe...Rockbursts, which mainly affect mining roadways, are dynamic disasters arising from the surrounding rock under high stress. Understanding the interaction between supports and the surrounding rock is necessary for effective rockburst control. In this study, the squeezing behavior of the surrounding rock is analyzed in rockburst roadways, and a mechanical model of rockbursts is established considering the dynamic support stress, thus deriving formulas and providing characteristic curves for describing the interaction between the support and surrounding rock. Design principles and parameters of supports for rockburst control are proposed. The results show that only when the geostress magnitude exceeds a critical value can it drive the formation of rockburst conditions. The main factors influencing the convergence response and rockburst occurrence around roadways are geostress, rock brittleness, uniaxial compressive strength, and roadway excavation size. Roadway support devices can play a role in controlling rockburst by suppressing the squeezing evolution of the surrounding rock towards instability points of rockburst. Further, the higher the strength and the longer the impact stroke of support devices with constant resistance, the more easily multiple balance points can be formed with the surrounding rock to control rockburst occurrence. Supports with long impact stroke allow adaptation to varying geostress levels around the roadway, aiding in rockburst control. The results offer a quantitative method for designing support systems for rockburst-prone roadways. The design criterion of supports is determined by the intersection between the convergence curve of the surrounding rock and the squeezing deformation curve of the support devices.展开更多
Maintaining the integrity and longevity of structures is essential in many industries,such as aerospace,nuclear,and petroleum.To achieve the cost-effectiveness of large-scale systems in petroleum drilling,a strong emp...Maintaining the integrity and longevity of structures is essential in many industries,such as aerospace,nuclear,and petroleum.To achieve the cost-effectiveness of large-scale systems in petroleum drilling,a strong emphasis on structural durability and monitoring is required.This study focuses on the mechanical vibrations that occur in rotary drilling systems,which have a substantial impact on the structural integrity of drilling equipment.The study specifically investigates axial,torsional,and lateral vibrations,which might lead to negative consequences such as bit-bounce,chaotic whirling,and high-frequency stick-slip.These events not only hinder the efficiency of drilling but also lead to exhaustion and harm to the system’s components since they are difficult to be detected and controlled in real time.The study investigates the dynamic interactions of these vibrations,specifically in their high-frequency modes,usingfield data obtained from measurement while drilling.Thefindings have demonstrated the effect of strong coupling between the high-frequency modes of these vibrations on drilling sys-tem performance.The obtained results highlight the importance of considering the interconnected impacts of these vibrations when designing and implementing robust control systems.Therefore,integrating these compo-nents can increase the durability of drill bits and drill strings,as well as improve the ability to monitor and detect damage.Moreover,by exploiting thesefindings,the assessment of structural resilience in rotary drilling systems can be enhanced.Furthermore,the study demonstrates the capacity of structural health monitoring to improve the quality,dependability,and efficiency of rotary drilling systems in the petroleum industry.展开更多
Rock discontinuities control rock mechanical behaviors and significantly influence the stability of rock masses.However,existing discontinuity mapping algorithms are susceptible to noise,and the calculation results ca...Rock discontinuities control rock mechanical behaviors and significantly influence the stability of rock masses.However,existing discontinuity mapping algorithms are susceptible to noise,and the calculation results cannot be fed back to users timely.To address this issue,we proposed a human-machine interaction(HMI)method for discontinuity mapping.Users can help the algorithm identify the noise and make real-time result judgments and parameter adjustments.For this,a regular cube was selected to illustrate the workflows:(1)point cloud was acquired using remote sensing;(2)the HMI method was employed to select reference points and angle thresholds to detect group discontinuity;(3)individual discontinuities were extracted from the group discontinuity using a density-based cluster algorithm;and(4)the orientation of each discontinuity was measured based on a plane fitting algorithm.The method was applied to a well-studied highway road cut and a complex natural slope.The consistency of the computational results with field measurements demonstrates its good accuracy,and the average error in the dip direction and dip angle for both cases was less than 3.Finally,the computational time of the proposed method was compared with two other popular algorithms,and the reduction in computational time by tens of times proves its high computational efficiency.This method provides geologists and geological engineers with a new idea to map rapidly and accurately rock structures under large amounts of noises or unclear features.展开更多
Correction to:Neuroscience Bulletin https://doi.org/10.1007/s12264-025-01371-x In this article the affiliation"Department of Circuit Theory,Faculty of Electrical Engineering,Czech Technical University in Prague,M...Correction to:Neuroscience Bulletin https://doi.org/10.1007/s12264-025-01371-x In this article the affiliation"Department of Circuit Theory,Faculty of Electrical Engineering,Czech Technical University in Prague,Member of the Epilepsy Research Centre Prague-EpiReC Consortium,Prague,Czechia"should only be assigned to Radek Janca and Petr Jezdik.It is removed from the authors:Jiri Hammer,Michaela Kajsova,Adam Kalina,Petr Marusic,and Kamil Vlcek.展开更多
The shop floor dynamic scheduling system based on human-computer interaction is the use of computer-aided decision-making and human-computer interaction to solve the dynamic scheduling problem.A human-computer interac...The shop floor dynamic scheduling system based on human-computer interaction is the use of computer-aided decision-making and human-computer interaction to solve the dynamic scheduling problem.A human-computer interaction interface based on Gantt chart is designed,which can not only comprehensively and quantitatively represent the scheduling process and scheduling scheme,but also have friendly human-computer interaction performance.The data transmission and interaction architecture is constructed to realize the rapid response to shop floor disturbance events.A priority calculation algorithm integrating priority rules and dispatcher preference is proposed,which realizes the automatic calculation of priority for the dispatcher's reference and reduces theirburden.A man-machine interactive shop floor dynamic scheduling strategy is proposed.When solving the dynamic flexible job shop scheduling problem caused by machine tool breakdown and urgent order,the origin moments obtained by using this strategy are 0.4190 and 0.3703 respectively.As can be seen from the origin moment indicator,the dynamic shop floor scheduling system based on the human-computer interaction is efficient and reliable in solving dynamic scheduling problems,and related strategies of this system are also feasible and stable.展开更多
Understanding the rheology of bentonite suspensions is crucial for ensuring the safety of engineering practices.However,the rheological mechanisms of bentonite remain unclear due to the limitations of conventional exp...Understanding the rheology of bentonite suspensions is crucial for ensuring the safety of engineering practices.However,the rheological mechanisms of bentonite remain unclear due to the limitations of conventional experimental techniques,particularly in assessing the microscopic interactions between clay particles and their impact on rheological properties.In this paper,the rheological behaviors of Namontmorillonite were studied with a focus on interparticle interactions.Both equilibrium molecular dynamics(MD)and non-equilibrium MD simulations were conducted to understand the physical properties of Na-montmorillonite under zero shear and various shear rates,respectively.The interaction between two parallel clay particles was determined in simulations,indicating that the classical Darjaguin-Landau-Verwey-Overbeek(DLVO)theory underestimates the interactions for a small separation distance.Na-montmorillonite exhibits a typical shear thinning behavior under shearing.However,as water content increases,it begins to behave more like liquid water.The yield stress of montmorillonite,as determined by the Bingham model,was found to be linearly related to the interaction pressures between clay particles.Besides MD simulations,the microstructure of clay suspension was further quantified using the separation distance and incline angle between non-parallel clay particles.Based on MD results and the quantified clay structure,a model was developed to estimate the yield stress of montmorillonite considering various influence factors,including electrolyte concentration,temperature,and solid fraction.Finally,from a comparison with calculated and experimental data,the results confirm the good performance of the proposed model.These findings provide significant insights for understanding the rheological soil behaviors and evaluating the yield stress of bentonite suspensions.展开更多
Photocatalytic CO_(2)reduction using atomically dispersed catalysts holds significant potential for addressing global energy and environmental challenges.However,the influence of d-d orbital interactions between metal...Photocatalytic CO_(2)reduction using atomically dispersed catalysts holds significant potential for addressing global energy and environmental challenges.However,the influence of d-d orbital interactions between metal centers and coordinated atoms remains under explored.Herein,nickel phthalocyanine is anchored to the metalexposed crystal face of TiO_(2),forming Ti-Ni-N_(4)coordination.This configuration reveals that the axially coordinated Ti atoms serve as a novel electron channel with electron-donating ability,transferring electrons to the Ni center through d-d coupling.It is found that the dynamic adjustment of bond lengths and d-band centers in Ti-Ni bonding during CO_(2)photoreduction process can effectively modulate the adsorption strengths of the Ni center for different intermediates.This leads to a significant enhancement in the photocatalytic performance for CO_(2)reduction to CO without a sacrificial reagent,achieving an exceptional CO evolution rate of 378.5μmol g^(-1).Furthermore,the d-d coupling mediated by Ti-Ni-N_(4)coordination increases the vacancy formation energy of active sites,preventing the leaching of Ni active centers.This study provides a strategy for the precise design of d-d orbital regulation and resistance to demetallization in photocatalysts for efficient CO_(2)conversion.展开更多
The coupled nonlocal nonlinear Schrödinger equations with variable coefficients are researched using the nonstandard Hirota bilinear method.The two-soliton and double-hump one-soliton solutions for the equations ...The coupled nonlocal nonlinear Schrödinger equations with variable coefficients are researched using the nonstandard Hirota bilinear method.The two-soliton and double-hump one-soliton solutions for the equations are first obtained.By assigning different functions to the variable coefficients,we obtain V-shaped,Y-shaped,wave-type,exponential solitons,and so on.Next,we reveal the influence of the real and imaginary parts of the wave numbers on the double-hump structure based on the soliton solutions.Finally,by setting different wave numbers,we can change the distance and transmission direction of the solitons to analyze their dynamic behavior during collisions.This study establishes a theoretical framework for controlling the dynamics of optical fiber in nonlocal nonlinear systems.展开更多
The equilibrium dynamics and nonlinear rheology of unentangled polymer blends remain inadequately understood,especially regarding the influence of short-chain matrix length N_(S) on the structure and rheological behav...The equilibrium dynamics and nonlinear rheology of unentangled polymer blends remain inadequately understood,especially regarding the influence of short-chain matrix length N_(S) on the structure and rheological behavior of dispersed long chains.Using molecular dynamics simulations based on the Kremer-Grest model,we systematically explore the N_(S)-dependence of static conformations,equilibrium dynamics,and nonlinear shear responses in unentangled long-chain/short-chain polymer blends.Our results demonstrate a decoupling between the static and dynamic sensitivity to N_(S):while the static chain size,R_g,follows Flory theory with slight swelling at small N_(S) due to incomplete excluded volume screening,the diffusion coefficient,D,and the relaxation time,τ_(0),exhibit a strong,non-monotonic N_(S)-dependence,transitioning from monomeric friction dominance at small N_(S) to collective segmental rearrangement at large N_(S).Additionally,we observe partial decoupling between the viscous and normal stress responses:while the zero-shear viscosity,η,is strongly N_(S)-dependent,the first and second normal stress coefficients,Ψ_(1) and Ψ_(2),collapse onto universal curves when scaled by the dimensionless shear rate,γτ_(0),suggesting a common mechanism of orientation and stretching.Under shear,long chains compress in the vorticity direction λ_(z)~Wi^(-0.2),which reduces collision frequency and contributes to shear thinning,while the scaling of weaker orientation resistance m_(G)~Wi^(0.35)reflects hydrodynamic screening by the short-chain matrix.These findings highlight the limitations of single-chain models and emphasize the necessity of considering N_(S)-dependent matrix dynamics and flow-induced structural changes in understanding the rheology of unentangled polymer blends.展开更多
Strong long-wavelength laser pulses enable direct manipulation of atomic lattices for engineering novel quantum states in complex materials.Nonlinear coupling between two infrared-active phonon modes(TO_(1) and TO_(2)...Strong long-wavelength laser pulses enable direct manipulation of atomic lattices for engineering novel quantum states in complex materials.Nonlinear coupling between two infrared-active phonon modes(TO_(1) and TO_(2)),induced by intense terahertz light fields,significantly enhances the amplitude of the TO_(1) mode and facilitates ultrafast control of transient structural distortions.This light-induced distortion reduces the lattice thermal conductivity from 8.1 W·m^(-1)·K^(-1)to 3.0 W·m^(-1)·K^(-1).The reduction originates from the nonlinear coupling,which enhances anharmonic interactions in the lattice potential energy and substantially shortens the phonon lifetime(τ).This work demonstrates a strategy applicable to other perovskite materials and provides a framework for investigating light-induced electrical,optical,and thermodynamic phase transitions.展开更多
A complete characterization of the behavior in human-robot interactions(HRI) includes both: the behavioral dynamics and the control laws that characterize how the behavior is regulated with the perception data. In thi...A complete characterization of the behavior in human-robot interactions(HRI) includes both: the behavioral dynamics and the control laws that characterize how the behavior is regulated with the perception data. In this way, this work proposes a leader-follower coordinate control based on an impedance control that allows to establish a dynamic relation between social forces and motion error. For this, a scheme is presented to identify the impedance based on fictitious social forces, which are described by distance-based potential fields.As part of the validation procedure, we present an experimental comparison to select the better of two different fictitious force structures. The criteria are determined by two qualities: least impedance errors during the validation procedure and least parameter variance during the recursive estimation procedure.Finally, with the best fictitious force and its identified impedance,an impedance control is designed for a mobile robot Pioneer 3AT,which is programmed to follow a human in a structured scenario.According to results, and under the hypothesis that moving like humans will be acceptable by humans, it is believed that the proposed control improves the social acceptance of the robot for this kind of interaction.展开更多
The method of inputting the seismic wave determines the accuracy of the simulation of soil-structure dynamic interaction. The wave method is a commonly used approach for seismic wave input, which converts the incident...The method of inputting the seismic wave determines the accuracy of the simulation of soil-structure dynamic interaction. The wave method is a commonly used approach for seismic wave input, which converts the incident wave into equivalent loads on the cutoff boundaries. The wave method has high precision, but the implementation is complicated, especially for three-dimensional models. By deducing another form of equivalent input seismic loads in the fi nite element model, a new seismic wave input method is proposed. In the new method, by imposing the displacements of the free wave fi eld on the nodes of the substructure composed of elements that contain artifi cial boundaries, the equivalent input seismic loads are obtained through dynamic analysis of the substructure. Subsequently, the equivalent input seismic loads are imposed on the artifi cial boundary nodes to complete the seismic wave input and perform seismic analysis of the soil-structure dynamic interaction model. Compared with the wave method, the new method is simplifi ed by avoiding the complex processes of calculating the equivalent input seismic loads. The validity of the new method is verifi ed by the dynamic analysis numerical examples of the homogeneous and layered half space under vertical and oblique incident seismic waves.展开更多
Journal bearings are important parts to keep the high dynamic performance of rotor machinery. Some methods have already been proposed to analysis the flow field of journal bearings, and in most of these methods simpli...Journal bearings are important parts to keep the high dynamic performance of rotor machinery. Some methods have already been proposed to analysis the flow field of journal bearings, and in most of these methods simplified physical model and classic Reynolds equation are always applied. While the application of the general computational fluid dynamics （CFD）-fluid structure interaction （FSI） techniques is more beneficial for analysis of the fluid field in a journal bearing when more detailed solutions are needed. This paper deals with the quasi-coupling calculation of transient fluid dynamics of oil film in journal bearings and rotor dynamics with CFD-FSI techniques. The fluid dynamics of oil film is calculated by applying the so-called ＂dynamic mesh＂ technique. A new mesh movement approacb is presented while the dynamic mesh models provided by FLUENT are not suitable for the transient oil flow in journal bearings. The proposed mesh movement approach is based on the structured mesh. When the joumal moves, the movement distance of every grid in the flow field of bearing can be calculated, and then the update of the volume mesh can be handled automatically by user defined function （UDF）. The journal displacement at each time step is obtained by solving the moving equations of the rotor-bearing system under the known oil film force condition. A case study is carried out to calculate the locus of the journal center and pressure distribution of the journal in order to prove the feasibility of this method. The calculating results indicate that the proposed method can predict the transient flow field of a journal bearing in a rotor-bearing system where more realistic models are involved. The presented calculation method provides a basis for studying the nonlinear dynamic behavior of a general rotor-bearing system.展开更多
Electromyography(EMG)has already been broadly used in human-machine interaction(HMI)applications.Determining how to decode the information inside EMG signals robustly and accurately is a key problem for which we urgen...Electromyography(EMG)has already been broadly used in human-machine interaction(HMI)applications.Determining how to decode the information inside EMG signals robustly and accurately is a key problem for which we urgently need a solution.Recently,many EMG pattern recognition tasks have been addressed using deep learning methods.In this paper,we analyze recent papers and present a literature review describing the role that deep learning plays in EMG-based HMI.An overview of typical network structures and processing schemes will be provided.Recent progress in typical tasks such as movement classification,joint angle prediction,and force/torque estimation will be introduced.New issues,including multimodal sensing,inter-subject/inter-session,and robustness toward disturbances will be discussed.We attempt to provide a comprehensive analysis of current research by discussing the advantages,challenges,and opportunities brought by deep learning.We hope that deep learning can aid in eliminating factors that hinder the development of EMG-based HMI systems.Furthermore,possible future directions will be presented to pave the way for future research.展开更多
Due to the wide applications of arches in underground protective structures, dynamic analysis of circular arches including soil-structure interactions is important. In this paper, an exact solution of the forced vibra...Due to the wide applications of arches in underground protective structures, dynamic analysis of circular arches including soil-structure interactions is important. In this paper, an exact solution of the forced vibration of circular arches subjected to subsurface denotation forces is obtained. The dynamic soil-structure interaction is considered with the introduction of an interfacial damping between the structure element and the surrounding soil into the equa- tion of motion. By neglecting the influences of shear, rotary inertia and tangential forces and assuming the arch incompressible, the equations of motion of the buried arches were set up. Analytical solutions of the dynamic responses of the protective arches were deduced by means of modal super- position. Arches with different opening angles, acoustic impedances and rise-span ratios were analyzed to discuss their influences on an arch. The theoretical analysis suggests blast loads for elastic designs and predicts the potential failure modes for buried protective arches.展开更多
The interactions between konjac glucomannan（KGM） and soy protein isolate （SPI） were studied with the method of molecular dynamics simulation. Part representative structures segments of KGM and SPI were used as mod...The interactions between konjac glucomannan（KGM） and soy protein isolate （SPI） were studied with the method of molecular dynamics simulation. Part representative structures segments of KGM and SPI were used as mode, and the force-field was FF03. The stability and sites of KGM/SPI interactions in water were researched at 363 K with the following results： the potential energy （EPOT） of the mixed gel dropped, while that of single KGM gel increased. The surface area （SA） of KGM in the mixed system was decreased to 401.41 from 1 267.54 Az, and that of SPI to 484.94 from 1 943.28 A2. The sum potential energy of KGM and soy protein in the mixed system was decreased to -13 402.41 from -5 768.56 kcal mol^-1. The variations of two parameters showed that the stability of compound gel KGM/SPI was improved, which was consistent with the previous studies. The sites of interactions in the mixed gel were the -OH groups on C（2） in KGM mannose and glucose, and the amide linkage group on Histidine, Asparagine and Leucine in SPI. The hydrogen bond was formed directly or indirectly by the bridge of waters.展开更多
This study focuses on the application of dynamic route planning and augmented reality(AR)technology within interactive theme trail platforms.Taking the“Dongpo Travelogue”digital guide mini-program as a case study,it...This study focuses on the application of dynamic route planning and augmented reality(AR)technology within interactive theme trail platforms.Taking the“Dongpo Travelogue”digital guide mini-program as a case study,it employs empirical analysis to explore its impact on enhancing visitor engagement and cultural identification.Employing a combined quantitative and qualitative methodology,the study analyses the platform’s functional implementation in route planning,cultural narration,interactive games,and their impact on visitor experience.Findings indicate that the integration of dynamic route planning and AR technology significantly enhances visitor engagement and cultural identity,offering novel insights for the digital transformation of the cultural tourism industry.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.12472279)。
文摘In bio-inspired flapping-wing flight,lift generation and flexible deformation are intrinsically coupled.Thus,an experimental study is conducted to reveal the fluid-structure interaction mechanism for a flexible plate undergoing pitching and plunging motion,and theoretical models are proposed to predict either lift or deformation based on a series of simplifying assumptions.It is indicated that flexible plates can effectively reduce the amplitude of lift and pitching moment coefficients during dynamic stall,with increased flexibility leading to higher load reduction.To investigate the effect of plate flexibility on lift,a definition of effective angle of attack is proposed,incorporating the pitching and plunging motion and chordwise deformation of the flexible plate,which can reduce the hysteresis effect of the lift coefficient during dynamic stall.As a consequence,a theoretical model is developed to predict lift based on observed motion and deformation.On the other hand,another theoretical model is developed to predict flexible-plate deformation utilizing aerodynamic forces,revealing the effect of leading-edge vortex evolution on passive deformation.The influence of kinematic parameters,including the maximum effective angle of attack,reduced frequency,and Strouhal number,on the aerodynamic forces is further studied.Compared with the rigid plate,flexible plates exhibit lower sensitivity of aerodynamic forces to changes in kinematic parameters due to their inherent compliance and resulting deformation.The proposed theoretical models can serve as a reference for aerodynamic and deformation prediction in bio-inspired flexible structures.
基金financially supported by the National Natural Science Foundation of China(No.52363007)。
文摘Recycling of waste rubber(WR)is crucial for the sustainable development of the rubber industry.The enhancement of interfacial interactions is the main strategy for waste polymer recycling.However,there is a lack of methods for enhancing the interfacial interactions for WR recycling because WR contains abundant inert C―H bonds.Herein,we designed thioctic acid inverse vulcanization copolymers to endow recycled WR with dynamic disulfide interfacial interactions,significantly improving the mechanical properties of recycled WR.These disulfide interfacial interactions among the recycled WR tend to exchange,which dramatically increases the fractocohesive length and prevents stress concentration near the crack tips.When recycled WR is subjected to external stress,the loads are redistributed across a broad region of adjacent regions instead of being concentrated on a limited length scale,which resists crack propagation.This work effectively recycled WR,providing a strategy for solvent-free reaction-derived inverse vulcanization copolymers to improve the toughness of WR recycling.
文摘Reliable traffic flow prediction is crucial for mitigating urban congestion.This paper proposes Attentionbased spatiotemporal Interactive Dynamic Graph Convolutional Network(AIDGCN),a novel architecture integrating Interactive Dynamic Graph Convolution Network(IDGCN)with Temporal Multi-Head Trend-Aware Attention.Its core innovation lies in IDGCN,which uniquely splits sequences into symmetric intervals for interactive feature sharing via dynamic graphs,and a novel attention mechanism incorporating convolutional operations to capture essential local traffic trends—addressing a critical gap in standard attention for continuous data.For 15-and 60-min forecasting on METR-LA,AIDGCN achieves MAEs of 0.75%and 0.39%,and RMSEs of 1.32%and 0.14%,respectively.In the 60-min long-term forecasting of the PEMS-BAY dataset,the AIDGCN out-performs the MRA-BGCN method by 6.28%,4.93%,and 7.17%in terms of MAE,RMSE,and MAPE,respectively.Experimental results demonstrate the superiority of our pro-posed model over state-of-the-art methods.
基金funded by the National Natural Science Foundation of China (No. 52304133)the National Key R&D Program of China (No. 2022YFC3004605)the Department of Science and Technology of Liaoning Province (No. 2023-BS-083)。
文摘Rockbursts, which mainly affect mining roadways, are dynamic disasters arising from the surrounding rock under high stress. Understanding the interaction between supports and the surrounding rock is necessary for effective rockburst control. In this study, the squeezing behavior of the surrounding rock is analyzed in rockburst roadways, and a mechanical model of rockbursts is established considering the dynamic support stress, thus deriving formulas and providing characteristic curves for describing the interaction between the support and surrounding rock. Design principles and parameters of supports for rockburst control are proposed. The results show that only when the geostress magnitude exceeds a critical value can it drive the formation of rockburst conditions. The main factors influencing the convergence response and rockburst occurrence around roadways are geostress, rock brittleness, uniaxial compressive strength, and roadway excavation size. Roadway support devices can play a role in controlling rockburst by suppressing the squeezing evolution of the surrounding rock towards instability points of rockburst. Further, the higher the strength and the longer the impact stroke of support devices with constant resistance, the more easily multiple balance points can be formed with the surrounding rock to control rockburst occurrence. Supports with long impact stroke allow adaptation to varying geostress levels around the roadway, aiding in rockburst control. The results offer a quantitative method for designing support systems for rockburst-prone roadways. The design criterion of supports is determined by the intersection between the convergence curve of the surrounding rock and the squeezing deformation curve of the support devices.
文摘Maintaining the integrity and longevity of structures is essential in many industries,such as aerospace,nuclear,and petroleum.To achieve the cost-effectiveness of large-scale systems in petroleum drilling,a strong emphasis on structural durability and monitoring is required.This study focuses on the mechanical vibrations that occur in rotary drilling systems,which have a substantial impact on the structural integrity of drilling equipment.The study specifically investigates axial,torsional,and lateral vibrations,which might lead to negative consequences such as bit-bounce,chaotic whirling,and high-frequency stick-slip.These events not only hinder the efficiency of drilling but also lead to exhaustion and harm to the system’s components since they are difficult to be detected and controlled in real time.The study investigates the dynamic interactions of these vibrations,specifically in their high-frequency modes,usingfield data obtained from measurement while drilling.Thefindings have demonstrated the effect of strong coupling between the high-frequency modes of these vibrations on drilling sys-tem performance.The obtained results highlight the importance of considering the interconnected impacts of these vibrations when designing and implementing robust control systems.Therefore,integrating these compo-nents can increase the durability of drill bits and drill strings,as well as improve the ability to monitor and detect damage.Moreover,by exploiting thesefindings,the assessment of structural resilience in rotary drilling systems can be enhanced.Furthermore,the study demonstrates the capacity of structural health monitoring to improve the quality,dependability,and efficiency of rotary drilling systems in the petroleum industry.
基金supported by the National Key R&D Program of China(No.2023YFC3081200)the National Natural Science Foundation of China(No.42077264)the Scientific Research Project of PowerChina Huadong Engineering Corporation Limited(HDEC-2022-0301).
文摘Rock discontinuities control rock mechanical behaviors and significantly influence the stability of rock masses.However,existing discontinuity mapping algorithms are susceptible to noise,and the calculation results cannot be fed back to users timely.To address this issue,we proposed a human-machine interaction(HMI)method for discontinuity mapping.Users can help the algorithm identify the noise and make real-time result judgments and parameter adjustments.For this,a regular cube was selected to illustrate the workflows:(1)point cloud was acquired using remote sensing;(2)the HMI method was employed to select reference points and angle thresholds to detect group discontinuity;(3)individual discontinuities were extracted from the group discontinuity using a density-based cluster algorithm;and(4)the orientation of each discontinuity was measured based on a plane fitting algorithm.The method was applied to a well-studied highway road cut and a complex natural slope.The consistency of the computational results with field measurements demonstrates its good accuracy,and the average error in the dip direction and dip angle for both cases was less than 3.Finally,the computational time of the proposed method was compared with two other popular algorithms,and the reduction in computational time by tens of times proves its high computational efficiency.This method provides geologists and geological engineers with a new idea to map rapidly and accurately rock structures under large amounts of noises or unclear features.
文摘Correction to:Neuroscience Bulletin https://doi.org/10.1007/s12264-025-01371-x In this article the affiliation"Department of Circuit Theory,Faculty of Electrical Engineering,Czech Technical University in Prague,Member of the Epilepsy Research Centre Prague-EpiReC Consortium,Prague,Czechia"should only be assigned to Radek Janca and Petr Jezdik.It is removed from the authors:Jiri Hammer,Michaela Kajsova,Adam Kalina,Petr Marusic,and Kamil Vlcek.
基金supported by the Tianjin Enterprise Science and Technology Commissioner Project(Grant No.23YDTPJC00740,Grant No.24YDTPJC00610)the Tianjin Tiankai Higher Education Science and Technology Innovation Park Enterprise R&D Special Project(Grant No.23YFZXYC00027).
文摘The shop floor dynamic scheduling system based on human-computer interaction is the use of computer-aided decision-making and human-computer interaction to solve the dynamic scheduling problem.A human-computer interaction interface based on Gantt chart is designed,which can not only comprehensively and quantitatively represent the scheduling process and scheduling scheme,but also have friendly human-computer interaction performance.The data transmission and interaction architecture is constructed to realize the rapid response to shop floor disturbance events.A priority calculation algorithm integrating priority rules and dispatcher preference is proposed,which realizes the automatic calculation of priority for the dispatcher's reference and reduces theirburden.A man-machine interactive shop floor dynamic scheduling strategy is proposed.When solving the dynamic flexible job shop scheduling problem caused by machine tool breakdown and urgent order,the origin moments obtained by using this strategy are 0.4190 and 0.3703 respectively.As can be seen from the origin moment indicator,the dynamic shop floor scheduling system based on the human-computer interaction is efficient and reliable in solving dynamic scheduling problems,and related strategies of this system are also feasible and stable.
基金the financial support provided by the National Science Fund for Distinguished Young Scholars of China(Grant No.42225702)the National Natural Science Fund of China for Excellent Young Scholars Fund(Overseas)+2 种基金Applied Basic Research Programme of Liaoning Province(2023JH2/101300139)Opening fund of State Key Laboratory of Geohazard Prevention and Geoenvironment Protection(Chengdu University of Technology,SKLGP2024K020)Key Laboratory of Earth Fissures Geological Disaster,Ministry of Natural Resources.
文摘Understanding the rheology of bentonite suspensions is crucial for ensuring the safety of engineering practices.However,the rheological mechanisms of bentonite remain unclear due to the limitations of conventional experimental techniques,particularly in assessing the microscopic interactions between clay particles and their impact on rheological properties.In this paper,the rheological behaviors of Namontmorillonite were studied with a focus on interparticle interactions.Both equilibrium molecular dynamics(MD)and non-equilibrium MD simulations were conducted to understand the physical properties of Na-montmorillonite under zero shear and various shear rates,respectively.The interaction between two parallel clay particles was determined in simulations,indicating that the classical Darjaguin-Landau-Verwey-Overbeek(DLVO)theory underestimates the interactions for a small separation distance.Na-montmorillonite exhibits a typical shear thinning behavior under shearing.However,as water content increases,it begins to behave more like liquid water.The yield stress of montmorillonite,as determined by the Bingham model,was found to be linearly related to the interaction pressures between clay particles.Besides MD simulations,the microstructure of clay suspension was further quantified using the separation distance and incline angle between non-parallel clay particles.Based on MD results and the quantified clay structure,a model was developed to estimate the yield stress of montmorillonite considering various influence factors,including electrolyte concentration,temperature,and solid fraction.Finally,from a comparison with calculated and experimental data,the results confirm the good performance of the proposed model.These findings provide significant insights for understanding the rheological soil behaviors and evaluating the yield stress of bentonite suspensions.
基金financially supported by the National Natural Science Foundation of China(No.22476042)the Natural Science Foundation of Hena.(No.242300421189)
文摘Photocatalytic CO_(2)reduction using atomically dispersed catalysts holds significant potential for addressing global energy and environmental challenges.However,the influence of d-d orbital interactions between metal centers and coordinated atoms remains under explored.Herein,nickel phthalocyanine is anchored to the metalexposed crystal face of TiO_(2),forming Ti-Ni-N_(4)coordination.This configuration reveals that the axially coordinated Ti atoms serve as a novel electron channel with electron-donating ability,transferring electrons to the Ni center through d-d coupling.It is found that the dynamic adjustment of bond lengths and d-band centers in Ti-Ni bonding during CO_(2)photoreduction process can effectively modulate the adsorption strengths of the Ni center for different intermediates.This leads to a significant enhancement in the photocatalytic performance for CO_(2)reduction to CO without a sacrificial reagent,achieving an exceptional CO evolution rate of 378.5μmol g^(-1).Furthermore,the d-d coupling mediated by Ti-Ni-N_(4)coordination increases the vacancy formation energy of active sites,preventing the leaching of Ni active centers.This study provides a strategy for the precise design of d-d orbital regulation and resistance to demetallization in photocatalysts for efficient CO_(2)conversion.
基金supported by the National Key R&D Program of China(Grant No.2022YFA1604200)the National Natural Science Foundation of China(Grant No.12261131495)Institute of Systems Science,Beijing Wuzi University(Grant No.BWUISS21).
文摘The coupled nonlocal nonlinear Schrödinger equations with variable coefficients are researched using the nonstandard Hirota bilinear method.The two-soliton and double-hump one-soliton solutions for the equations are first obtained.By assigning different functions to the variable coefficients,we obtain V-shaped,Y-shaped,wave-type,exponential solitons,and so on.Next,we reveal the influence of the real and imaginary parts of the wave numbers on the double-hump structure based on the soliton solutions.Finally,by setting different wave numbers,we can change the distance and transmission direction of the solitons to analyze their dynamic behavior during collisions.This study establishes a theoretical framework for controlling the dynamics of optical fiber in nonlocal nonlinear systems.
基金financially supported by the National Natural Science Foundation of China(Nos.22341304,22303100 and 12205270)the National Key R&D Program of China(Nos.2023YFA1008800 and 2020YFA0713601)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDC0180303)。
文摘The equilibrium dynamics and nonlinear rheology of unentangled polymer blends remain inadequately understood,especially regarding the influence of short-chain matrix length N_(S) on the structure and rheological behavior of dispersed long chains.Using molecular dynamics simulations based on the Kremer-Grest model,we systematically explore the N_(S)-dependence of static conformations,equilibrium dynamics,and nonlinear shear responses in unentangled long-chain/short-chain polymer blends.Our results demonstrate a decoupling between the static and dynamic sensitivity to N_(S):while the static chain size,R_g,follows Flory theory with slight swelling at small N_(S) due to incomplete excluded volume screening,the diffusion coefficient,D,and the relaxation time,τ_(0),exhibit a strong,non-monotonic N_(S)-dependence,transitioning from monomeric friction dominance at small N_(S) to collective segmental rearrangement at large N_(S).Additionally,we observe partial decoupling between the viscous and normal stress responses:while the zero-shear viscosity,η,is strongly N_(S)-dependent,the first and second normal stress coefficients,Ψ_(1) and Ψ_(2),collapse onto universal curves when scaled by the dimensionless shear rate,γτ_(0),suggesting a common mechanism of orientation and stretching.Under shear,long chains compress in the vorticity direction λ_(z)~Wi^(-0.2),which reduces collision frequency and contributes to shear thinning,while the scaling of weaker orientation resistance m_(G)~Wi^(0.35)reflects hydrodynamic screening by the short-chain matrix.These findings highlight the limitations of single-chain models and emphasize the necessity of considering N_(S)-dependent matrix dynamics and flow-induced structural changes in understanding the rheology of unentangled polymer blends.
基金Project supported by the National Key Research and Development Program of China(Grant No.2024YFF0508503)。
文摘Strong long-wavelength laser pulses enable direct manipulation of atomic lattices for engineering novel quantum states in complex materials.Nonlinear coupling between two infrared-active phonon modes(TO_(1) and TO_(2)),induced by intense terahertz light fields,significantly enhances the amplitude of the TO_(1) mode and facilitates ultrafast control of transient structural distortions.This light-induced distortion reduces the lattice thermal conductivity from 8.1 W·m^(-1)·K^(-1)to 3.0 W·m^(-1)·K^(-1).The reduction originates from the nonlinear coupling,which enhances anharmonic interactions in the lattice potential energy and substantially shortens the phonon lifetime(τ).This work demonstrates a strategy applicable to other perovskite materials and provides a framework for investigating light-induced electrical,optical,and thermodynamic phase transitions.
文摘A complete characterization of the behavior in human-robot interactions(HRI) includes both: the behavioral dynamics and the control laws that characterize how the behavior is regulated with the perception data. In this way, this work proposes a leader-follower coordinate control based on an impedance control that allows to establish a dynamic relation between social forces and motion error. For this, a scheme is presented to identify the impedance based on fictitious social forces, which are described by distance-based potential fields.As part of the validation procedure, we present an experimental comparison to select the better of two different fictitious force structures. The criteria are determined by two qualities: least impedance errors during the validation procedure and least parameter variance during the recursive estimation procedure.Finally, with the best fictitious force and its identified impedance,an impedance control is designed for a mobile robot Pioneer 3AT,which is programmed to follow a human in a structured scenario.According to results, and under the hypothesis that moving like humans will be acceptable by humans, it is believed that the proposed control improves the social acceptance of the robot for this kind of interaction.
基金National Natural Science Foundation of China under Grant No.51478247National Key Research and Development Program of China under Grant No.2016YFC1402800
文摘The method of inputting the seismic wave determines the accuracy of the simulation of soil-structure dynamic interaction. The wave method is a commonly used approach for seismic wave input, which converts the incident wave into equivalent loads on the cutoff boundaries. The wave method has high precision, but the implementation is complicated, especially for three-dimensional models. By deducing another form of equivalent input seismic loads in the fi nite element model, a new seismic wave input method is proposed. In the new method, by imposing the displacements of the free wave fi eld on the nodes of the substructure composed of elements that contain artifi cial boundaries, the equivalent input seismic loads are obtained through dynamic analysis of the substructure. Subsequently, the equivalent input seismic loads are imposed on the artifi cial boundary nodes to complete the seismic wave input and perform seismic analysis of the soil-structure dynamic interaction model. Compared with the wave method, the new method is simplifi ed by avoiding the complex processes of calculating the equivalent input seismic loads. The validity of the new method is verifi ed by the dynamic analysis numerical examples of the homogeneous and layered half space under vertical and oblique incident seismic waves.
基金supported by National Hi-tech Research and Development Program of China (863 Program, Grant No. 2009AA04Z413)Zhejiang Provincial Natural Science Foundation of China (Grant No. Y1110109)
文摘Journal bearings are important parts to keep the high dynamic performance of rotor machinery. Some methods have already been proposed to analysis the flow field of journal bearings, and in most of these methods simplified physical model and classic Reynolds equation are always applied. While the application of the general computational fluid dynamics （CFD）-fluid structure interaction （FSI） techniques is more beneficial for analysis of the fluid field in a journal bearing when more detailed solutions are needed. This paper deals with the quasi-coupling calculation of transient fluid dynamics of oil film in journal bearings and rotor dynamics with CFD-FSI techniques. The fluid dynamics of oil film is calculated by applying the so-called ＂dynamic mesh＂ technique. A new mesh movement approacb is presented while the dynamic mesh models provided by FLUENT are not suitable for the transient oil flow in journal bearings. The proposed mesh movement approach is based on the structured mesh. When the joumal moves, the movement distance of every grid in the flow field of bearing can be calculated, and then the update of the volume mesh can be handled automatically by user defined function （UDF）. The journal displacement at each time step is obtained by solving the moving equations of the rotor-bearing system under the known oil film force condition. A case study is carried out to calculate the locus of the journal center and pressure distribution of the journal in order to prove the feasibility of this method. The calculating results indicate that the proposed method can predict the transient flow field of a journal bearing in a rotor-bearing system where more realistic models are involved. The presented calculation method provides a basis for studying the nonlinear dynamic behavior of a general rotor-bearing system.
基金supported in part by the National Natural Science Foundation of China(U181321461773369+2 种基金61903360)the Selfplanned Project of the State Key Laboratory of Robotics(2020-Z12)China Postdoctoral Science Foundation funded project(2019M661155)。
文摘Electromyography(EMG)has already been broadly used in human-machine interaction(HMI)applications.Determining how to decode the information inside EMG signals robustly and accurately is a key problem for which we urgently need a solution.Recently,many EMG pattern recognition tasks have been addressed using deep learning methods.In this paper,we analyze recent papers and present a literature review describing the role that deep learning plays in EMG-based HMI.An overview of typical network structures and processing schemes will be provided.Recent progress in typical tasks such as movement classification,joint angle prediction,and force/torque estimation will be introduced.New issues,including multimodal sensing,inter-subject/inter-session,and robustness toward disturbances will be discussed.We attempt to provide a comprehensive analysis of current research by discussing the advantages,challenges,and opportunities brought by deep learning.We hope that deep learning can aid in eliminating factors that hinder the development of EMG-based HMI systems.Furthermore,possible future directions will be presented to pave the way for future research.
基金supported by the Funds for Creative Research Groups of China(51021001)the National Natural Science Foundation of China(51078351)Program for New Century Excellent Talents in University,Fund of Key Laboratory of Bridge-structure Engineering and Open Fund of Key Laboratory of Road & Bridge and Underground Engineering of Gansu Province(KFJJ-11-03)
文摘Due to the wide applications of arches in underground protective structures, dynamic analysis of circular arches including soil-structure interactions is important. In this paper, an exact solution of the forced vibration of circular arches subjected to subsurface denotation forces is obtained. The dynamic soil-structure interaction is considered with the introduction of an interfacial damping between the structure element and the surrounding soil into the equa- tion of motion. By neglecting the influences of shear, rotary inertia and tangential forces and assuming the arch incompressible, the equations of motion of the buried arches were set up. Analytical solutions of the dynamic responses of the protective arches were deduced by means of modal super- position. Arches with different opening angles, acoustic impedances and rise-span ratios were analyzed to discuss their influences on an arch. The theoretical analysis suggests blast loads for elastic designs and predicts the potential failure modes for buried protective arches.
基金supported by the National Natural Science Foundation of China(30871749,30901004)
文摘The interactions between konjac glucomannan（KGM） and soy protein isolate （SPI） were studied with the method of molecular dynamics simulation. Part representative structures segments of KGM and SPI were used as mode, and the force-field was FF03. The stability and sites of KGM/SPI interactions in water were researched at 363 K with the following results： the potential energy （EPOT） of the mixed gel dropped, while that of single KGM gel increased. The surface area （SA） of KGM in the mixed system was decreased to 401.41 from 1 267.54 Az, and that of SPI to 484.94 from 1 943.28 A2. The sum potential energy of KGM and soy protein in the mixed system was decreased to -13 402.41 from -5 768.56 kcal mol^-1. The variations of two parameters showed that the stability of compound gel KGM/SPI was improved, which was consistent with the previous studies. The sites of interactions in the mixed gel were the -OH groups on C（2） in KGM mannose and glucose, and the amide linkage group on Histidine, Asparagine and Leucine in SPI. The hydrogen bond was formed directly or indirectly by the bridge of waters.
文摘This study focuses on the application of dynamic route planning and augmented reality(AR)technology within interactive theme trail platforms.Taking the“Dongpo Travelogue”digital guide mini-program as a case study,it employs empirical analysis to explore its impact on enhancing visitor engagement and cultural identification.Employing a combined quantitative and qualitative methodology,the study analyses the platform’s functional implementation in route planning,cultural narration,interactive games,and their impact on visitor experience.Findings indicate that the integration of dynamic route planning and AR technology significantly enhances visitor engagement and cultural identity,offering novel insights for the digital transformation of the cultural tourism industry.
