In multi-orbital systems,the correlation strength is typically attributed to Coulomb interactions and Hund's couplings.However,this study demonstrates that on-site inter-orbital hybridization can also significant ...In multi-orbital systems,the correlation strength is typically attributed to Coulomb interactions and Hund's couplings.However,this study demonstrates that on-site inter-orbital hybridization can also significant influence the correlation strength of the system.We investigate the impact of on-site inter-orbital hybridization on the correlation strength of a two-orbital Hubbard model on a square lattice using the dynamical mean-field theory combined with Lanczos exact diagonalization.Our findings reveal a distinct Janus effect:on-site inter-orbital hybridization enhances correlation strength in the non-half-filled regime while suppresses it at half-filling.This dual role of on-site inter-orbital hybridization provides a fundamental mechanism for tuning the strength of correlations in multi-orbital systems.展开更多
The dynamic characteristics of the track system can directly affect its service performance and failure process.To explore the load characteristics and dynamic response of the track system under the dynamic loads from...The dynamic characteristics of the track system can directly affect its service performance and failure process.To explore the load characteristics and dynamic response of the track system under the dynamic loads from the rack vehicle in traction conditions,a systematic test of the track subsystem was carried out on a large-slope test line.In the test,the bending stress of the rack teeth,the wheel-rail forces,and the acceleration of crucial components in the track system were measured.Subsequently,a detailed analysis was conducted on the tested signals of the rack railway track system in the time domain and the time-frequency domains.The test results indicate that the traction force significantly affects the rack tooth bending stress and the wheel-rail forces.The vibrations of the track system under the traction conditions are mainly caused by the impacts generated from the gear-rack engagement,which are then transferred to the sleepers,the rails,and the ballast beds.Furthermore,both the maximum stress on the racks and the wheel-rail forces measured on the rails remain below their allowable values.This experimental study evaluates the load characteristics and reveals the vibration characteristics of the rack railway track system under the vehicle’s ultimate load,which is very important for the load-strengthening design of the key components such as racks and the vibration and noise reduction of the track system.展开更多
In this manuscript,we consider a non-autonomous dynamical system.Using the Carathéodory structure,we define a BS dimension on an arbitrary subset and obtain a Bowen’s equation that illustrates the relation of th...In this manuscript,we consider a non-autonomous dynamical system.Using the Carathéodory structure,we define a BS dimension on an arbitrary subset and obtain a Bowen’s equation that illustrates the relation of the BS dimension to the Pesin-Pitskel topological pressure given by Nazarian[24].Moreover,we establish a variational principle and an inverse variational principle for the BS dimension of non-autonomous dynamical systems.Finally,we also get an analogue of Billingsley’s theorem for the BS dimension of non-autonomous dynamical systems.展开更多
With the increasing complexity of logistics operations,traditional static vehicle routing models are no longer sufficient.In practice,customer demands often arise dynamically,and multi-depot systems are commonly used ...With the increasing complexity of logistics operations,traditional static vehicle routing models are no longer sufficient.In practice,customer demands often arise dynamically,and multi-depot systems are commonly used to improve efficiency.This paper first introduces a vehicle routing problem with the goal of minimizing operating costs in a multi-depot environment with dynamic demand.New customers appear in the delivery process at any time and are periodically optimized according to time slices.Then,we propose a scheduling system TS-DPU based on an improved ant colony algorithm TS-ACO to solve this problem.The classical ant colony algorithm uses spatial distance to select nodes,while TS-ACO considers the impact of both temporal and spatial distance on node selection.Meanwhile,we adopt Cordeau’s Multi-Depot Vehicle Routing Problem with Time Windows(MDVRPTW)dataset to evaluate the performance of our system.According to the experimental results,TS-ACO,which considers spatial and temporal distance,is more effective than the classical ACO,which only considers spatial distance.展开更多
The water hammer problem is an important issue in the dynamics of liquid propulsion system.This paper aims to use the Lattice Boltzmann Method(LBM)with entropy limiter to study the water hammer problems in propellant ...The water hammer problem is an important issue in the dynamics of liquid propulsion system.This paper aims to use the Lattice Boltzmann Method(LBM)with entropy limiter to study the water hammer problems in propellant feedlines.The dynamic characteristics of valve-closing water hammer and filling water hammer are investigated by this method,and the sensitivity of filling water hammer is analyzed with a single factor sensitivity analysis with 8 factors and 9 levels and a multi-factor sensitivity analysis with L_(27)(3^(13))orthogonal experiment based on range method.It is found that the solving result of LBM with entropy limiter is basically in good agreement with finite volume method,and using the entropy limiter can eliminate numerical oscillations when solving valve-closing water hammer problems and solve the numerical"blow up"when solving filling water hammer problems.It can be seen that the dynamic characteristics of valve-closing water hammer are relatively simple,while there are many factors that affect the filling water hammer and the degree of these effects varies.The effects on the maximum water hammer pressure are relatively uniform,but those on the water hammer response time vary greatly through the skewness analysis.展开更多
In the context of power generation companies, vast amounts of specialized data and expert knowledge have been accumulated. However, challenges such as data silos and fragmented knowledge hinder the effective utilizati...In the context of power generation companies, vast amounts of specialized data and expert knowledge have been accumulated. However, challenges such as data silos and fragmented knowledge hinder the effective utilization of this information. This study proposes a novel framework for intelligent Question-and-Answer (Q&A) systems based on Retrieval-Augmented Generation (RAG) to address these issues. The system efficiently acquires domain-specific knowledge by leveraging external databases, including Relational Databases (RDBs) and graph databases, without additional fine-tuning for Large Language Models (LLMs). Crucially, the framework integrates a Dynamic Knowledge Base Updating Mechanism (DKBUM) and a Weighted Context-Aware Similarity (WCAS) method to enhance retrieval accuracy and mitigate inherent limitations of LLMs, such as hallucinations and lack of specialization. Additionally, the proposed DKBUM dynamically adjusts knowledge weights within the database, ensuring that the most recent and relevant information is utilized, while WCAS refines the alignment between queries and knowledge items by enhanced context understanding. Experimental validation demonstrates that the system can generate timely, accurate, and context-sensitive responses, making it a robust solution for managing complex business logic in specialized industries.展开更多
This paper addresses urban sustainability challenges amid global urbanization, emphasizing the need for innova tive approaches aligned with the Sustainable Development Goals. While traditional tools and linear models ...This paper addresses urban sustainability challenges amid global urbanization, emphasizing the need for innova tive approaches aligned with the Sustainable Development Goals. While traditional tools and linear models offer insights, they fall short in presenting a holistic view of complex urban challenges. System dynamics (SD) models that are often utilized to provide holistic, systematic understanding of a research subject, like the urban system, emerge as valuable tools, but data scarcity and theoretical inadequacy pose challenges. The research reviews relevant papers on recent SD model applications in urban sustainability since 2018, categorizing them based on nine key indicators. Among the reviewed papers, data limitations and model assumptions were identified as ma jor challenges in applying SD models to urban sustainability. This led to exploring the transformative potential of big data analytics, a rare approach in this field as identified by this study, to enhance SD models’ empirical foundation. Integrating big data could provide data-driven calibration, potentially improving predictive accuracy and reducing reliance on simplified assumptions. The paper concludes by advocating for new approaches that reduce assumptions and promote real-time applicable models, contributing to a comprehensive understanding of urban sustainability through the synergy of big data and SD models.展开更多
The real-time path optimization for heterogeneous vehicle fleets in large-scale road networks presents significant challenges due to conflicting traffic demands and imbalanced resource allocation.While existing vehicl...The real-time path optimization for heterogeneous vehicle fleets in large-scale road networks presents significant challenges due to conflicting traffic demands and imbalanced resource allocation.While existing vehicleto-infrastructure coordination frameworks partially address congestion mitigation,they often neglect priority-aware optimization and exhibit algorithmic bias toward dominant vehicle classes—critical limitations in mixed-priority scenarios involving emergency vehicles.To bridge this gap,this study proposes a preference game-theoretic coordination framework with adaptive strategy transfer protocol,explicitly balancing system-wide efficiency(measured by network throughput)with priority vehicle rights protection(quantified via time-sensitive utility functions).The approach innovatively combines(1)a multi-vehicle dynamic routing model with quantifiable preference weights,and(2)a distributed Nash equilibrium solver updated using replicator sub-dynamic models.The framework was evaluated on an urban road network containing 25 intersections with mixed priority ratios(10%–30%of vehicles with priority access demand),and the framework showed consistent benefits on four benchmarks(Social routing algorithm,Shortest path algorithm,The comprehensive path optimisation model,The emergency vehicle timing collaborative evolution path optimization method)showed consistent benefits.Results showthat across different traffic demand configurations,the proposed method reduces the average vehicle traveling time by at least 365 s,increases the road network throughput by 48.61%,and effectively balances the road loads.This approach successfully meets the diverse traffic demands of various vehicle types while optimizing road resource allocations.The proposed coordination paradigm advances theoretical foundations for fairness-aware traffic optimization while offering implementable strategies for next-generation cooperative vehicle-road systems,particularly in smart city deployments requiring mixed-priority mobility guarantees.展开更多
The coupling effects of rainfall,earthquake,and complex topographic and geological conditions complicate the dynamic responses and disasters of slope-tunnel systems.For this,the large-scale shaking table tests were ca...The coupling effects of rainfall,earthquake,and complex topographic and geological conditions complicate the dynamic responses and disasters of slope-tunnel systems.For this,the large-scale shaking table tests were carried out to explore the dynamic responses of steep bedding slope-tunnel system under the coupling effect of rainfall and earthquake.Results show that the slope surface and elevation amplification effect exhibit pronounced nonlinear change caused by the tunnel and weak interlayers.When seismic wave propagates to tunnels,the weak interlayers and rock intersecting areas present complex wave field distribution characteristics.The dynamic responses of the slope are influenced by the frequency,amplitude,and direction of seismic waves.The acceleration amplification coefficient initially rises and then falls as increasing seismic frequency,peaking at 20 Hz.Additionally,the seismic damage process of slope is categorized into elastic(2-3 m/s^(2)),elastoplastic(4-5 m/s^(2))and plastic damage stages(≥6.5 m/s^(2)).In elastic stage,ΔMPGA(ratio of acceleration amplification factor)increases with increasing seismic intensity,without obvious strain distribution change.In plastic stage,ΔMPGA begins to gradually plummet,and the strain is mainly distributed in the damaged area.The modes of seismic damage in the slope-tunnel system are mainly of tensile failure of the weak interlayer,cracking failure of tunnel lining,formation of persistent cracks on the slope crest and waist,development and outward shearing of the sliding mass,and buckling failure at the slope foot under extrusion of the upper rock body.This study can serve as a reference for predicting the failure modes of tunnel-slope system in strong seismic regions.展开更多
The integration of renewable energy sources(RESs)with inverter interfaces has fundamentally reshaped power system dynamics,challenging traditional stability analysis frameworks designed for synchronous generator-domin...The integration of renewable energy sources(RESs)with inverter interfaces has fundamentally reshaped power system dynamics,challenging traditional stability analysis frameworks designed for synchronous generator-dominated grids.Conventional classifica-tions,which decouple voltage,frequency,and rotor angle stability,fail to address the emerging strong voltage‒angle coupling effects caused by RES dynamics.This coupling introduces complex oscillation modes and undermines system robustness,neces-sitating novel stability assessment tools.Recent studies focus on eigenvalue distributions and damping redistribution but lack quantitative criteria and interpretative clarity for coupled stability.This work proposes a transient energy-based framework to resolve these gaps.By decomposing transient energy into subsystem-dissipated components and coupling-induced energy exchange,the method establishes stability criteria compatible with a broad variety of inverter-interfaced devices while offering an intuitive energy-based interpretation for engineers.The coupling strength is also quantified by defining the relative coupling strength index,which is directly related to the transient energy interpretation of the coupled stability.Angle‒voltage coupling may induce instability by injecting transient energy into the system,even if the individual phase angle and voltage dynamics themselves are stable.The main contributions include a systematic stability evaluation framework and an energy decomposition approach that bridges theoretical analysis with practical applicability,addressing the urgent need for tools for managing modern power system evolving stability challenges.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
Urban transportation systems are facing severe challenges due to the rapid growth of the urban population,especially in China.Suspended monorail system(SMS),as a sky rail transportation form,can effectively alleviate ...Urban transportation systems are facing severe challenges due to the rapid growth of the urban population,especially in China.Suspended monorail system(SMS),as a sky rail transportation form,can effectively alleviate urban traffic congestion due to its independent right-of-way and minimal ground footprint.However,the SMS possesses a special traveling system with unique vehicle structure and bridge configuration,which results in significant differences in both the mechanisms and dynamics problems associated with train–bridge interaction(TBI)when contrasted with those of traditional railway systems.Therefore,a thorough understanding of the SMS dynamics is essential for ensuring the operational safety of the system.This article presents a state-of-the-art review of the TBI modeling methodologies,critical dynamic features,field tests,and practice of the SMS in China.Firstly,the development history,technical features,and potential dynamics problems of the SMS are briefly described,followed by the mechanical characteristics and mechanisms of the train–bridge interactive systems.Then,the modeling methodology of the fundamental elements in the suspended monorail TBI is systematically reviewed,including the suspended train subsystem,bridge subsystem,train–bridge interaction relationships,system excitations,and solution method.Further,the typical dynamic features of the TBI under various operational scenarios are elaborated,including different train speeds,a variety of line sections,and a natural wind environment.Finally,the first new energy-based SMS test line in the world is systematically introduced,including the composition and functionality of the system,the details of the conducted field tests,and the measured results of the typical dynamic responses.At the end of the paper,both the guidance on further improvement of the SMS and future research topics are proposed.展开更多
The high-speed winding spindle employs a flexible support system incorporating rubber O-rings.By precisely configuring the structural parameters and the number of the O-rings,the spindle can stably surpass its critica...The high-speed winding spindle employs a flexible support system incorporating rubber O-rings.By precisely configuring the structural parameters and the number of the O-rings,the spindle can stably surpass its critical speed points and maintain operational stability across the entire working speed range.However,the support stiffness and damping of rubber O-rings exhibit significant nonlinear frequency dependence.Conventional experimental methods for deriving equivalent stiffness and damping,based on the principle of the forced non-resonance method,require fabricating custom setups for each O-ring specification and conducting vibration tests at varying frequencies,resulting in low efficiency and high costs.This study proposes a hybrid simulation-experimental method for dynamic parameter identification.Firstly,the frequency-dependent dynamic parameters of a specific O-ring support system are experimentally obtained.Subsequently,a corresponding parametric finite element model is established to simulate and solve the equivalent elastic modulus and equivalent stiffness-damping coefficient of this O-ring support system.Ultimately,after iterative simulation,the simulated and experimental results achieve a 99.7%agreement.The parametric finite element model developed herein can directly simulate and inversely estimate frequency-dependent dynamic parameters for O-rings of different specifications but identical elastic modulus.展开更多
This paper establishes a method for identifying and locating dynamic loads in time-varying systems.The proposed method linearizes time-varying parameters within small time units and uses the Wilson-θ inverse analysis...This paper establishes a method for identifying and locating dynamic loads in time-varying systems.The proposed method linearizes time-varying parameters within small time units and uses the Wilson-θ inverse analysis method to solve modal loads of each order at each time step.It then uses an exhaustive method to determine the load position.Finally,it calculates the time history of the load.Simulation examples demonstrate how the number of measuring points and step size affect load identi-fication accuracy,verifying that this algorithm achieves good identification accuracy for loads under resonance conditions.Additionally,it explores how noise affects load position and recognition accuracy,while providing a solution.Simulation examples and experimental results demonstrate that the proposed method can identify both the time history and position of loads simultaneously with high identification accuracy.展开更多
Multi-robot coordinated towing system is an under-constrained system.The dynamic response of the towing system can not be fully controlled since the rope can only provide a unidirectional constraint force to the suspe...Multi-robot coordinated towing system is an under-constrained system.The dynamic response of the towing system can not be fully controlled since the rope can only provide a unidirectional constraint force to the suspended object.Based on the kinematics of the multi-robot coordinated towing system with fixed-base,the Newton-Euler equations and Udwadia-Kalaba equations were used to establish the dynamics of the towing system.To obtain the motion trajectories with high stability and strong control,the motion trajectories of the towing system were optimized.During the towing,the transition from the relaxation state to the tension state of the rope was treated as a collision between the suspended object and the robot end.The trajectories of the towing system in terms of a single-variable and multiple-variable were solved,respectively.The simulation shows that the optimized trajectories are closer to reality and truly reflect the constraints of the ropes on the suspended object.The research results provide a basis for trajectory planning and control of the towing system.展开更多
The integration of artificial intelligence(AI)with advanced power technologies is transforming energy system management,particularly through real-time data monitoring and intelligent decision-making driven by Artifici...The integration of artificial intelligence(AI)with advanced power technologies is transforming energy system management,particularly through real-time data monitoring and intelligent decision-making driven by Artificial Intelligence Generated Content(AIGC).However,the openness of power system channels and the resource-constrained nature of power sensors have led to new challenges for the secure transmission of power data and decision instructions.Although traditional public key cryptographic primitives can offer high security,the substantial key management and computational overhead associated with these primitives make them unsuitable for power systems.To ensure the real-time and security of power data and command transmission,we propose a lightweight identity authentication scheme tailored for power AIGC systems.The scheme utilizes lightweight symmetric encryption algorithms,minimizing the resource overhead on power sensors.Additionally,it incorporates a dynamic credential update mechanism,which can realize the rotation and update of temporary credentials to ensure anonymity and security.We rigorously validate the security of the scheme using the Real-or-Random(ROR)model and AVISPA simulation,and the results show that our scheme can resist various active and passive attacks.Finally,performance comparisons and NS3 simulation results demonstrate that our proposed scheme offers enhanced security features with lower overhead,making it more suitable for power AIGC systems compared to existing solutions.展开更多
Dynamical decoupling(DD),usually implemented by sophisticated sequences of instantaneous control pulses,is a well-established quantum control technique for quantum information and quantum sensing.In practice,the pulse...Dynamical decoupling(DD),usually implemented by sophisticated sequences of instantaneous control pulses,is a well-established quantum control technique for quantum information and quantum sensing.In practice,the pulses are inevitably imperfect with many systematic errors that may influence the performances of DD.In particular,Rabi error and detuning are primary systemic errors arising from finite pulse duration,incorrect time control,and frequency instability.Here,we propose a phase-modulated DD with staggered global phases for the basic units of the pulse sequences to suppress these systemic errors.By varying the global phases appended to the pulses in the dynamical decoupling unit alternatively with 0 orπ,our protocol can significantly reduce the influences of Rabi error and detuning.Our protocol is general and can be combined with the most existing DD sequences such as universal DD,knill DD,XY,etc.As an example,we further apply our method to quantum lock-in detection for measuring time-dependent alternating signals.Our study paves the way for a simple and feasible way to realize robust dynamical decoupling sequences,which can be applicable for various quantum sensing scenarios.展开更多
Particulate photocatalytic systems using nanoscale photocatalysts have been developed as an attractive promising route for solar energy utilization to achieve resource sustainability and environmental harmony.Dynamic ...Particulate photocatalytic systems using nanoscale photocatalysts have been developed as an attractive promising route for solar energy utilization to achieve resource sustainability and environmental harmony.Dynamic obstacles are considered as the dominant inhibition for attaining satisfactory energy-conversion efficiency.The complexity in light absorption and carrier transfer behaviors has remained to be further clearly illuminated.It is challenging to trace the fast evolution of charge carriers involved in transfer migration and interfacial reactions within a micro–nano-single-particle photocatalyst,which requires spatiotemporal high resolution.In this review,comprehensive dynamic descriptions including irradiation field,carrier separation and transfer,and interfacial reaction processes have been elucidated and discussed.The corresponding mechanisms for revealing dynamic behaviors have been explained.In addition,numerical simulation and modeling methods have been illustrated for the description of the irradiation field.Experimental measurements and spatiotemporal characterizations have been clarified for the reflection of carrier behavior and probing detection of interfacial reactions.The representative applications have been introduced according to the reported advanced research works,and the relationships between mechanistic conclusions from variable spatiotemporal measurements and photocatalytic performance results in the specific photocatalytic reactions have been concluded.This review provides a collective perspective for the full understanding and thorough evaluation of the primary dynamic processes,which would be inspired for the improvement in designing solar-driven energy-conversion systems based on nanoscale particulate photocatalysts.展开更多
Background:This article examines the impact of the release of Wolbachia-infected population replacement mosquitoes as an innovative strategy for managing and controlling dengue in the Americas,using an approach based ...Background:This article examines the impact of the release of Wolbachia-infected population replacement mosquitoes as an innovative strategy for managing and controlling dengue in the Americas,using an approach based on the system dynamics methodology.The introduction of Wolbachia-carrying mosquitoes aims to reduce dengue transmission by interfering with the reproductive capacity of mosquitoes,thus limiting the spread of the virus.Objective:the objective of this study is to analyze how this intervention affects not only the incidence of dengue but also the health care system,evaluating changes in the demand for medical services and the costs associated with treatment in health care institutions.Specifically,it looks at the cost per visit to an Epidemiologist,a Family Doctor,diagnostic tests,and hospitalization.Methods:the study uses simulation scenarios to model the potential impact of the Wolbachia-based intervention in reducing dengue cases and its associated health and economic burden.The scenarios also assess the optimization of resources and improvements in the health system’s response to epidemic outbreaks.The simulation model utilizes real data from the Americas region to enhance the accuracy and relevance of the results.Conclusion:The results the potential of the release of Wolbachia-carrying mosquitoes to significantly mitigate the health and economic burden of dengue,with a maximum saving of 60.15%in the best simulation scenario.The approach not only highlights scientific innovation but also demonstrates its potential influence on public policy design.The findings support the implementation of sustainable strategies to maximize the benefits of this intervention and ensure its effective integration into public health programs,contributing to better long-term dengue management.展开更多
Using quantum discord(QD)and geometric quantum discord(GQD),quantum correlation dynamics is investigated for two coupled qubits within a multiqubit interacting system in the zero-temperature bosonic reservoir,under bo...Using quantum discord(QD)and geometric quantum discord(GQD),quantum correlation dynamics is investigated for two coupled qubits within a multiqubit interacting system in the zero-temperature bosonic reservoir,under both weak and strong qubit-reservoir coupling regimes.The multiqubit system is connected with either a common bosonic reservoir(CBR)or multiple independent bosonic reservoirs(IBRs).In the CBR case,our findings indicate that both QD and GQD can be strengthened by increasing the number of qubits in the multiqubit system.Furthermore,we study the steady state QD and GQD in the strong coupling regime,and find that the stable value in the long-time limit is determined exclusively by the number of qubits.The evolution period of QD and GQD gets longer as the dipole–dipole interaction(DDI)strength increases,which helps prolong the correlation time and thus preserves the quantum correlation under the weak coupling regime.Further analysis reveals notable differences between the CBR and IBRs scenarios.In the IBRs case,the decay of QD and GQD becomes slower compared to the CBR case,with both measures tending to zero at a reduced rate.Moreover,GQD consistently exhibits lower values than QD in both scenarios.These findings provide valuable insights into the selection of appropriate correlation measurement techniques for quantifying quantum correlations.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.12174327)the Natural Science Foundation of Shandong Province,China(Grant No.ZR2023ZD09)。
文摘In multi-orbital systems,the correlation strength is typically attributed to Coulomb interactions and Hund's couplings.However,this study demonstrates that on-site inter-orbital hybridization can also significant influence the correlation strength of the system.We investigate the impact of on-site inter-orbital hybridization on the correlation strength of a two-orbital Hubbard model on a square lattice using the dynamical mean-field theory combined with Lanczos exact diagonalization.Our findings reveal a distinct Janus effect:on-site inter-orbital hybridization enhances correlation strength in the non-half-filled regime while suppresses it at half-filling.This dual role of on-site inter-orbital hybridization provides a fundamental mechanism for tuning the strength of correlations in multi-orbital systems.
基金supported by the National Natural Science Foundation of China(No.52388102)the Sichuan Science and Technology Program(No.2024NSFTD0011)the Fundamental Research Funds for the State Key Laboratory of Rail Transit Vehicle System of Southwest Jiaotong University(No.2023TPL-T11).
文摘The dynamic characteristics of the track system can directly affect its service performance and failure process.To explore the load characteristics and dynamic response of the track system under the dynamic loads from the rack vehicle in traction conditions,a systematic test of the track subsystem was carried out on a large-slope test line.In the test,the bending stress of the rack teeth,the wheel-rail forces,and the acceleration of crucial components in the track system were measured.Subsequently,a detailed analysis was conducted on the tested signals of the rack railway track system in the time domain and the time-frequency domains.The test results indicate that the traction force significantly affects the rack tooth bending stress and the wheel-rail forces.The vibrations of the track system under the traction conditions are mainly caused by the impacts generated from the gear-rack engagement,which are then transferred to the sleepers,the rails,and the ballast beds.Furthermore,both the maximum stress on the racks and the wheel-rail forces measured on the rails remain below their allowable values.This experimental study evaluates the load characteristics and reveals the vibration characteristics of the rack railway track system under the vehicle’s ultimate load,which is very important for the load-strengthening design of the key components such as racks and the vibration and noise reduction of the track system.
基金supported by the NSFC(12461012)and the NSF of Chongqing(CSTB2024NSCQ-MSX1246).
文摘In this manuscript,we consider a non-autonomous dynamical system.Using the Carathéodory structure,we define a BS dimension on an arbitrary subset and obtain a Bowen’s equation that illustrates the relation of the BS dimension to the Pesin-Pitskel topological pressure given by Nazarian[24].Moreover,we establish a variational principle and an inverse variational principle for the BS dimension of non-autonomous dynamical systems.Finally,we also get an analogue of Billingsley’s theorem for the BS dimension of non-autonomous dynamical systems.
基金supported by the Startup Foundation for Introducing Talent of Nanjing University of Information Science and Technology.
文摘With the increasing complexity of logistics operations,traditional static vehicle routing models are no longer sufficient.In practice,customer demands often arise dynamically,and multi-depot systems are commonly used to improve efficiency.This paper first introduces a vehicle routing problem with the goal of minimizing operating costs in a multi-depot environment with dynamic demand.New customers appear in the delivery process at any time and are periodically optimized according to time slices.Then,we propose a scheduling system TS-DPU based on an improved ant colony algorithm TS-ACO to solve this problem.The classical ant colony algorithm uses spatial distance to select nodes,while TS-ACO considers the impact of both temporal and spatial distance on node selection.Meanwhile,we adopt Cordeau’s Multi-Depot Vehicle Routing Problem with Time Windows(MDVRPTW)dataset to evaluate the performance of our system.According to the experimental results,TS-ACO,which considers spatial and temporal distance,is more effective than the classical ACO,which only considers spatial distance.
基金supported by the Natural Science BasicResearch Program of Shaanxi,China(No.2021JC-14)。
文摘The water hammer problem is an important issue in the dynamics of liquid propulsion system.This paper aims to use the Lattice Boltzmann Method(LBM)with entropy limiter to study the water hammer problems in propellant feedlines.The dynamic characteristics of valve-closing water hammer and filling water hammer are investigated by this method,and the sensitivity of filling water hammer is analyzed with a single factor sensitivity analysis with 8 factors and 9 levels and a multi-factor sensitivity analysis with L_(27)(3^(13))orthogonal experiment based on range method.It is found that the solving result of LBM with entropy limiter is basically in good agreement with finite volume method,and using the entropy limiter can eliminate numerical oscillations when solving valve-closing water hammer problems and solve the numerical"blow up"when solving filling water hammer problems.It can be seen that the dynamic characteristics of valve-closing water hammer are relatively simple,while there are many factors that affect the filling water hammer and the degree of these effects varies.The effects on the maximum water hammer pressure are relatively uniform,but those on the water hammer response time vary greatly through the skewness analysis.
文摘In the context of power generation companies, vast amounts of specialized data and expert knowledge have been accumulated. However, challenges such as data silos and fragmented knowledge hinder the effective utilization of this information. This study proposes a novel framework for intelligent Question-and-Answer (Q&A) systems based on Retrieval-Augmented Generation (RAG) to address these issues. The system efficiently acquires domain-specific knowledge by leveraging external databases, including Relational Databases (RDBs) and graph databases, without additional fine-tuning for Large Language Models (LLMs). Crucially, the framework integrates a Dynamic Knowledge Base Updating Mechanism (DKBUM) and a Weighted Context-Aware Similarity (WCAS) method to enhance retrieval accuracy and mitigate inherent limitations of LLMs, such as hallucinations and lack of specialization. Additionally, the proposed DKBUM dynamically adjusts knowledge weights within the database, ensuring that the most recent and relevant information is utilized, while WCAS refines the alignment between queries and knowledge items by enhanced context understanding. Experimental validation demonstrates that the system can generate timely, accurate, and context-sensitive responses, making it a robust solution for managing complex business logic in specialized industries.
基金sponsored by the U.S.Department of Housing and Urban Development(Grant No.NJLTS0027-22)The opinions expressed in this study are the authors alone,and do not represent the U.S.Depart-ment of HUD’s opinions.
文摘This paper addresses urban sustainability challenges amid global urbanization, emphasizing the need for innova tive approaches aligned with the Sustainable Development Goals. While traditional tools and linear models offer insights, they fall short in presenting a holistic view of complex urban challenges. System dynamics (SD) models that are often utilized to provide holistic, systematic understanding of a research subject, like the urban system, emerge as valuable tools, but data scarcity and theoretical inadequacy pose challenges. The research reviews relevant papers on recent SD model applications in urban sustainability since 2018, categorizing them based on nine key indicators. Among the reviewed papers, data limitations and model assumptions were identified as ma jor challenges in applying SD models to urban sustainability. This led to exploring the transformative potential of big data analytics, a rare approach in this field as identified by this study, to enhance SD models’ empirical foundation. Integrating big data could provide data-driven calibration, potentially improving predictive accuracy and reducing reliance on simplified assumptions. The paper concludes by advocating for new approaches that reduce assumptions and promote real-time applicable models, contributing to a comprehensive understanding of urban sustainability through the synergy of big data and SD models.
基金funded by the National Key Research and Development Program Project 2022YFB4300404.
文摘The real-time path optimization for heterogeneous vehicle fleets in large-scale road networks presents significant challenges due to conflicting traffic demands and imbalanced resource allocation.While existing vehicleto-infrastructure coordination frameworks partially address congestion mitigation,they often neglect priority-aware optimization and exhibit algorithmic bias toward dominant vehicle classes—critical limitations in mixed-priority scenarios involving emergency vehicles.To bridge this gap,this study proposes a preference game-theoretic coordination framework with adaptive strategy transfer protocol,explicitly balancing system-wide efficiency(measured by network throughput)with priority vehicle rights protection(quantified via time-sensitive utility functions).The approach innovatively combines(1)a multi-vehicle dynamic routing model with quantifiable preference weights,and(2)a distributed Nash equilibrium solver updated using replicator sub-dynamic models.The framework was evaluated on an urban road network containing 25 intersections with mixed priority ratios(10%–30%of vehicles with priority access demand),and the framework showed consistent benefits on four benchmarks(Social routing algorithm,Shortest path algorithm,The comprehensive path optimisation model,The emergency vehicle timing collaborative evolution path optimization method)showed consistent benefits.Results showthat across different traffic demand configurations,the proposed method reduces the average vehicle traveling time by at least 365 s,increases the road network throughput by 48.61%,and effectively balances the road loads.This approach successfully meets the diverse traffic demands of various vehicle types while optimizing road resource allocations.The proposed coordination paradigm advances theoretical foundations for fairness-aware traffic optimization while offering implementable strategies for next-generation cooperative vehicle-road systems,particularly in smart city deployments requiring mixed-priority mobility guarantees.
基金supported by the National Natural Science Foundation of China (Grant No.52109125)the Natural Science Foundation of Jiangsu Province,China (Grant No.BK20231217)the Key Laboratory of Geomechanics and Geotechnical Engineering Safety,Chinese Academy of Sciences (Grant No.SKLGME023001).
文摘The coupling effects of rainfall,earthquake,and complex topographic and geological conditions complicate the dynamic responses and disasters of slope-tunnel systems.For this,the large-scale shaking table tests were carried out to explore the dynamic responses of steep bedding slope-tunnel system under the coupling effect of rainfall and earthquake.Results show that the slope surface and elevation amplification effect exhibit pronounced nonlinear change caused by the tunnel and weak interlayers.When seismic wave propagates to tunnels,the weak interlayers and rock intersecting areas present complex wave field distribution characteristics.The dynamic responses of the slope are influenced by the frequency,amplitude,and direction of seismic waves.The acceleration amplification coefficient initially rises and then falls as increasing seismic frequency,peaking at 20 Hz.Additionally,the seismic damage process of slope is categorized into elastic(2-3 m/s^(2)),elastoplastic(4-5 m/s^(2))and plastic damage stages(≥6.5 m/s^(2)).In elastic stage,ΔMPGA(ratio of acceleration amplification factor)increases with increasing seismic intensity,without obvious strain distribution change.In plastic stage,ΔMPGA begins to gradually plummet,and the strain is mainly distributed in the damaged area.The modes of seismic damage in the slope-tunnel system are mainly of tensile failure of the weak interlayer,cracking failure of tunnel lining,formation of persistent cracks on the slope crest and waist,development and outward shearing of the sliding mass,and buckling failure at the slope foot under extrusion of the upper rock body.This study can serve as a reference for predicting the failure modes of tunnel-slope system in strong seismic regions.
基金supported by the Science and Technology Project of China Southern Power Grid Co.,Ltd under Grant 036000KC23090004(GDKJXM20231026).
文摘The integration of renewable energy sources(RESs)with inverter interfaces has fundamentally reshaped power system dynamics,challenging traditional stability analysis frameworks designed for synchronous generator-dominated grids.Conventional classifica-tions,which decouple voltage,frequency,and rotor angle stability,fail to address the emerging strong voltage‒angle coupling effects caused by RES dynamics.This coupling introduces complex oscillation modes and undermines system robustness,neces-sitating novel stability assessment tools.Recent studies focus on eigenvalue distributions and damping redistribution but lack quantitative criteria and interpretative clarity for coupled stability.This work proposes a transient energy-based framework to resolve these gaps.By decomposing transient energy into subsystem-dissipated components and coupling-induced energy exchange,the method establishes stability criteria compatible with a broad variety of inverter-interfaced devices while offering an intuitive energy-based interpretation for engineers.The coupling strength is also quantified by defining the relative coupling strength index,which is directly related to the transient energy interpretation of the coupled stability.Angle‒voltage coupling may induce instability by injecting transient energy into the system,even if the individual phase angle and voltage dynamics themselves are stable.The main contributions include a systematic stability evaluation framework and an energy decomposition approach that bridges theoretical analysis with practical applicability,addressing the urgent need for tools for managing modern power system evolving stability challenges.
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 Natural Science Foundation of China(Grant Nos.52202483,52108476,and 52388102)。
文摘Urban transportation systems are facing severe challenges due to the rapid growth of the urban population,especially in China.Suspended monorail system(SMS),as a sky rail transportation form,can effectively alleviate urban traffic congestion due to its independent right-of-way and minimal ground footprint.However,the SMS possesses a special traveling system with unique vehicle structure and bridge configuration,which results in significant differences in both the mechanisms and dynamics problems associated with train–bridge interaction(TBI)when contrasted with those of traditional railway systems.Therefore,a thorough understanding of the SMS dynamics is essential for ensuring the operational safety of the system.This article presents a state-of-the-art review of the TBI modeling methodologies,critical dynamic features,field tests,and practice of the SMS in China.Firstly,the development history,technical features,and potential dynamics problems of the SMS are briefly described,followed by the mechanical characteristics and mechanisms of the train–bridge interactive systems.Then,the modeling methodology of the fundamental elements in the suspended monorail TBI is systematically reviewed,including the suspended train subsystem,bridge subsystem,train–bridge interaction relationships,system excitations,and solution method.Further,the typical dynamic features of the TBI under various operational scenarios are elaborated,including different train speeds,a variety of line sections,and a natural wind environment.Finally,the first new energy-based SMS test line in the world is systematically introduced,including the composition and functionality of the system,the details of the conducted field tests,and the measured results of the typical dynamic responses.At the end of the paper,both the guidance on further improvement of the SMS and future research topics are proposed.
基金National Key R&D Program of China(No.2017YFB1304000)Fundamental Research Funds for the Central Universities,China(No.2232023G-05-1)。
文摘The high-speed winding spindle employs a flexible support system incorporating rubber O-rings.By precisely configuring the structural parameters and the number of the O-rings,the spindle can stably surpass its critical speed points and maintain operational stability across the entire working speed range.However,the support stiffness and damping of rubber O-rings exhibit significant nonlinear frequency dependence.Conventional experimental methods for deriving equivalent stiffness and damping,based on the principle of the forced non-resonance method,require fabricating custom setups for each O-ring specification and conducting vibration tests at varying frequencies,resulting in low efficiency and high costs.This study proposes a hybrid simulation-experimental method for dynamic parameter identification.Firstly,the frequency-dependent dynamic parameters of a specific O-ring support system are experimentally obtained.Subsequently,a corresponding parametric finite element model is established to simulate and solve the equivalent elastic modulus and equivalent stiffness-damping coefficient of this O-ring support system.Ultimately,after iterative simulation,the simulated and experimental results achieve a 99.7%agreement.The parametric finite element model developed herein can directly simulate and inversely estimate frequency-dependent dynamic parameters for O-rings of different specifications but identical elastic modulus.
基金supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘This paper establishes a method for identifying and locating dynamic loads in time-varying systems.The proposed method linearizes time-varying parameters within small time units and uses the Wilson-θ inverse analysis method to solve modal loads of each order at each time step.It then uses an exhaustive method to determine the load position.Finally,it calculates the time history of the load.Simulation examples demonstrate how the number of measuring points and step size affect load identi-fication accuracy,verifying that this algorithm achieves good identification accuracy for loads under resonance conditions.Additionally,it explores how noise affects load position and recognition accuracy,while providing a solution.Simulation examples and experimental results demonstrate that the proposed method can identify both the time history and position of loads simultaneously with high identification accuracy.
基金the National Natural Science Foundation of China(No.51965032)the Natural Science Foundation of Gansu Province of China(No.22JR5RA319)+1 种基金the Science and Technology Foundation of Gansu Province of China(No.21YF5WA060)the Excellent Doctoral Student Foundation of Gansu Province of China(No.23JRRA842)。
文摘Multi-robot coordinated towing system is an under-constrained system.The dynamic response of the towing system can not be fully controlled since the rope can only provide a unidirectional constraint force to the suspended object.Based on the kinematics of the multi-robot coordinated towing system with fixed-base,the Newton-Euler equations and Udwadia-Kalaba equations were used to establish the dynamics of the towing system.To obtain the motion trajectories with high stability and strong control,the motion trajectories of the towing system were optimized.During the towing,the transition from the relaxation state to the tension state of the rope was treated as a collision between the suspended object and the robot end.The trajectories of the towing system in terms of a single-variable and multiple-variable were solved,respectively.The simulation shows that the optimized trajectories are closer to reality and truly reflect the constraints of the ropes on the suspended object.The research results provide a basis for trajectory planning and control of the towing system.
文摘The integration of artificial intelligence(AI)with advanced power technologies is transforming energy system management,particularly through real-time data monitoring and intelligent decision-making driven by Artificial Intelligence Generated Content(AIGC).However,the openness of power system channels and the resource-constrained nature of power sensors have led to new challenges for the secure transmission of power data and decision instructions.Although traditional public key cryptographic primitives can offer high security,the substantial key management and computational overhead associated with these primitives make them unsuitable for power systems.To ensure the real-time and security of power data and command transmission,we propose a lightweight identity authentication scheme tailored for power AIGC systems.The scheme utilizes lightweight symmetric encryption algorithms,minimizing the resource overhead on power sensors.Additionally,it incorporates a dynamic credential update mechanism,which can realize the rotation and update of temporary credentials to ensure anonymity and security.We rigorously validate the security of the scheme using the Real-or-Random(ROR)model and AVISPA simulation,and the results show that our scheme can resist various active and passive attacks.Finally,performance comparisons and NS3 simulation results demonstrate that our proposed scheme offers enhanced security features with lower overhead,making it more suitable for power AIGC systems compared to existing solutions.
基金Project supported by the National Key Research and Development Program of China(Grant No.2022YFA1404104)the National Natural Science Foundation of China(Grant Nos.92476201,12025509,12305022,and 12475029)+1 种基金the Key-Area Research and Development Program of Guangdong Province,China(Grant No.2019B030330001)Guangdong Provincial Quantum Science Strategic Initiative Fund(Grant Nos.GDZX2305006 and GDZX2405002)。
文摘Dynamical decoupling(DD),usually implemented by sophisticated sequences of instantaneous control pulses,is a well-established quantum control technique for quantum information and quantum sensing.In practice,the pulses are inevitably imperfect with many systematic errors that may influence the performances of DD.In particular,Rabi error and detuning are primary systemic errors arising from finite pulse duration,incorrect time control,and frequency instability.Here,we propose a phase-modulated DD with staggered global phases for the basic units of the pulse sequences to suppress these systemic errors.By varying the global phases appended to the pulses in the dynamical decoupling unit alternatively with 0 orπ,our protocol can significantly reduce the influences of Rabi error and detuning.Our protocol is general and can be combined with the most existing DD sequences such as universal DD,knill DD,XY,etc.As an example,we further apply our method to quantum lock-in detection for measuring time-dependent alternating signals.Our study paves the way for a simple and feasible way to realize robust dynamical decoupling sequences,which can be applicable for various quantum sensing scenarios.
基金supported by the Project of National Natural Science Foundation of China(22102095,21773153)the National Key Basic Research and Development Program(2018YFB1502001)financial support from the program of China Scholarships Council(No.202306230242).
文摘Particulate photocatalytic systems using nanoscale photocatalysts have been developed as an attractive promising route for solar energy utilization to achieve resource sustainability and environmental harmony.Dynamic obstacles are considered as the dominant inhibition for attaining satisfactory energy-conversion efficiency.The complexity in light absorption and carrier transfer behaviors has remained to be further clearly illuminated.It is challenging to trace the fast evolution of charge carriers involved in transfer migration and interfacial reactions within a micro–nano-single-particle photocatalyst,which requires spatiotemporal high resolution.In this review,comprehensive dynamic descriptions including irradiation field,carrier separation and transfer,and interfacial reaction processes have been elucidated and discussed.The corresponding mechanisms for revealing dynamic behaviors have been explained.In addition,numerical simulation and modeling methods have been illustrated for the description of the irradiation field.Experimental measurements and spatiotemporal characterizations have been clarified for the reflection of carrier behavior and probing detection of interfacial reactions.The representative applications have been introduced according to the reported advanced research works,and the relationships between mechanistic conclusions from variable spatiotemporal measurements and photocatalytic performance results in the specific photocatalytic reactions have been concluded.This review provides a collective perspective for the full understanding and thorough evaluation of the primary dynamic processes,which would be inspired for the improvement in designing solar-driven energy-conversion systems based on nanoscale particulate photocatalysts.
文摘Background:This article examines the impact of the release of Wolbachia-infected population replacement mosquitoes as an innovative strategy for managing and controlling dengue in the Americas,using an approach based on the system dynamics methodology.The introduction of Wolbachia-carrying mosquitoes aims to reduce dengue transmission by interfering with the reproductive capacity of mosquitoes,thus limiting the spread of the virus.Objective:the objective of this study is to analyze how this intervention affects not only the incidence of dengue but also the health care system,evaluating changes in the demand for medical services and the costs associated with treatment in health care institutions.Specifically,it looks at the cost per visit to an Epidemiologist,a Family Doctor,diagnostic tests,and hospitalization.Methods:the study uses simulation scenarios to model the potential impact of the Wolbachia-based intervention in reducing dengue cases and its associated health and economic burden.The scenarios also assess the optimization of resources and improvements in the health system’s response to epidemic outbreaks.The simulation model utilizes real data from the Americas region to enhance the accuracy and relevance of the results.Conclusion:The results the potential of the release of Wolbachia-carrying mosquitoes to significantly mitigate the health and economic burden of dengue,with a maximum saving of 60.15%in the best simulation scenario.The approach not only highlights scientific innovation but also demonstrates its potential influence on public policy design.The findings support the implementation of sustainable strategies to maximize the benefits of this intervention and ensure its effective integration into public health programs,contributing to better long-term dengue management.
基金supported by the National Natural Science Foundation of China(Grant Nos.11564013 and 11964010)the Natural Science Foundation of Hunan Province(Grant No.2020JJ4495)the Scientific Research Fund of Hunan Provincial Education Department,China(Grant Nos.22A0377 and 21A0333).
文摘Using quantum discord(QD)and geometric quantum discord(GQD),quantum correlation dynamics is investigated for two coupled qubits within a multiqubit interacting system in the zero-temperature bosonic reservoir,under both weak and strong qubit-reservoir coupling regimes.The multiqubit system is connected with either a common bosonic reservoir(CBR)or multiple independent bosonic reservoirs(IBRs).In the CBR case,our findings indicate that both QD and GQD can be strengthened by increasing the number of qubits in the multiqubit system.Furthermore,we study the steady state QD and GQD in the strong coupling regime,and find that the stable value in the long-time limit is determined exclusively by the number of qubits.The evolution period of QD and GQD gets longer as the dipole–dipole interaction(DDI)strength increases,which helps prolong the correlation time and thus preserves the quantum correlation under the weak coupling regime.Further analysis reveals notable differences between the CBR and IBRs scenarios.In the IBRs case,the decay of QD and GQD becomes slower compared to the CBR case,with both measures tending to zero at a reduced rate.Moreover,GQD consistently exhibits lower values than QD in both scenarios.These findings provide valuable insights into the selection of appropriate correlation measurement techniques for quantifying quantum correlations.
