In the modern era of ubiquitous and highly interconnected information technology,cybersecurity threats stemming from software code vulnerabilities have become increasingly severe,posing significant risks to the confid...In the modern era of ubiquitous and highly interconnected information technology,cybersecurity threats stemming from software code vulnerabilities have become increasingly severe,posing significant risks to the confidentiality,integrity,and availability of modern information systems.To enhance software code quality,enterprises often integrate static code analysis tools into Continuous Integration(CI) pipelines.However,the high rates of false positives and false negatives remain a challenge.The advent of large language models(LLMs),such as ChatGPT,presents a new opportunity to address these challenges.In this paper,we propose AI-SCDF,a framework that utilizes the custombuilt Nebula-Coder AI model for detecting and fixing code security issues in real time during the developer ' s personal build process.We construct a static code checking rule knowledge base through summarizing and classifying Common Weakness Enumeration(CWE) code security problems identified by security and quality assurance teams.The rule knowledge base is combined with CodeFuse-processed code contexts to serve as input for an AI code security detection microservice,which assists in identifying code quality and security issues.If any abnormalities are detected,they are addressed by an AI code security patching microservice,which alerts the developer and requests confirmation before committing the code into the repository.Experimental results show that our approach effectively improves code quality.We also develop a VS Code plugin for code alert detection and fix based on LLMs,which facilitates test shift-left and lowers the risk of software development.展开更多
To improve the theoretical prediction accuracy of static mechanical quantities in MEMS cantilever beams for microwave power detection chips,a distributed static model is proposed based on the deflection equation.An an...To improve the theoretical prediction accuracy of static mechanical quantities in MEMS cantilever beams for microwave power detection chips,a distributed static model is proposed based on the deflection equation.An analytical frame-work is established through the precise characterization of cantilever beam bending.The framework can accurately extract key electromechanical parameters,and the correlation between these parameters and geometric changes is systematically studied.Results show that the pull-in voltage increases with the gap but decreases with the length.The predicted pull-in voltage indi-cates a relative error of only 6.5%between the distributed static model and the simulation,which is significantly lower than that of the other two models.The overload power and sensitivity are also analyzed to facilitate performance trade-offs in chip design.The measured return loss varies between-66.46 and-10.56 dB over the 8-12 GHz frequency band,exhibiting a charac-teristic V-shaped trend.Moreover,the measured sensitivity of 66.5 fF/W closely matches the theoretical value of 69.3 fF/W,show-ing a relative error of 5.6%.These findings confirm that the distributed model outperforms the other two in terms of both accu-racy and physical realism,thereby providing important reference for the design of microwave power detection chips.展开更多
Reactive compatibilization has been widely applied to enhance the compatibility of polymer blends,thereby improving their mechanical properties.However,it generally reduces the chain mobility and regularity,often lead...Reactive compatibilization has been widely applied to enhance the compatibility of polymer blends,thereby improving their mechanical properties.However,it generally reduces the chain mobility and regularity,often leading to slower polymer crystallization.Here,we demonstrate that reactive compatibilization in poly(lactic acid)/poly(butylene adipate-co-terephthalate)(PLA/PBAT)blends unexpectedly promotes PLA matrix crystallization during injection molding,in contrast to the retarded kinetics observed in differential scanning calorimetry isothermal crystallization studies.The phase morphology,rheological behavior,and crystalline structure were systematically analyzed to elucidate markedly different crystallization kinetics under static and shear fields.The potential mechanism underlying crystallization enhancement is attributed to PBAT domain refinement and viscosity increase induced by reactive compatibilization,which,under shear flow,create favorable conditions for crystallization by enhancing PBAT fibril nucleation and retarding the relaxation of oriented PLA chains.This study offers new perspectives on the effect of reactive compatibilization on the polymer crystallization behavior.展开更多
This study provides a new experimental framework to measure the static and dynamic electrical parameters for a solar panel of multiple cells.The study evaluates its static parameters,including its resultant diodes’sa...This study provides a new experimental framework to measure the static and dynamic electrical parameters for a solar panel of multiple cells.The study evaluates its static parameters,including its resultant diodes’saturation currents,diodes’ideality factors,series,and shunt resistances.Such parameters are essential to characterise the steady-state performance of a solar panel.Additionally,the dynamic parameters as the equivalent junction and diffusion capacitances are also experimentally measured.These parameters impact the performance of the panel at variable solar irradiance,temperature,and load conditions.A solar panel of 36 series-connected cells has been utilised in this research to undertake this experimental evaluation.This work addresses a gap in the recent literature regarding a full evaluation of the internal electrical parameters in a whole solar panel of multiple cells.Firstly,a dark experimental environment has been developed so that no influence from external light sources can affect the measurements being taken.The panel is then stimulated with different types of electrical stresses in various circuit configurations to measure the required static and dynamic parameters.For the solar panel under study,the series and shunt resistances per cell have been evaluated to be 18.91 mΩand 5.6 kΩ,respectively,while the junction and diffusion capacitances have shown direct and inverse relationships,respectively,with the applied voltage as expected.The outcomes of these experimental setups highlighted the importance of the developed comprehensive framework in this research to be employed to assess the quality of the solar panel and its real-time performance at variable operational conditions.展开更多
Single-pass and double-pass high-temperature deformation experiments were conducted on 40Cr10Si2Mo steel using a Gleeble-3500 thermal simulator.The static recrystallization(SRX)behavior and recrystallization mechanism...Single-pass and double-pass high-temperature deformation experiments were conducted on 40Cr10Si2Mo steel using a Gleeble-3500 thermal simulator.The static recrystallization(SRX)behavior and recrystallization mechanisms of 40Cr10Si2Mo steel were investigated under deformation temperatures of 900-1100℃,deformation strains of 10%,20%,and 30%,and inter-pass times of 1-120 s.A static recrystallization fraction model was developed.The results showed that the SRX volume fraction increased with higher deformation temperature,larger deformation amount,and longer inter-pass time,with the deformation temperature having the most significant effect on SRX.During the deformation process,different process parameters led to different internal deformation mechanisms of the material.Static recovery and continuous static recrystallization(CSRX)dominated deformation at lower temperatures through progressive lattice rotation.In comparison,at higher temperatures,the deformation mechanism was dominated by CSRX and discontinuous static recrystallization(DSRX).The nucleation mechanisms of the SRX process were grain boundary bulging nucleation and subgrain merging nucleation,with grain boundary bulging present under all conditions.Subgrain merging nucleation could provide an additional nucleation mode at lower deformation temperatures or lower deformation amounts.Based on the traditional Avarmi equation,a modified model coefficient was used to establish the SRX kinetic model for 40Cr10Si2Mo steel.The linear correlation coefficient R^(2) between the predicted and experimental static recrystallization volume fraction was 0.96702,indicating high prediction accuracy.展开更多
An optimized volt-ampere reactive(VAR)control framework is proposed for transmission-level power systems to simultaneously mitigate voltage deviations and active-power losses through coordinated control of large-scale...An optimized volt-ampere reactive(VAR)control framework is proposed for transmission-level power systems to simultaneously mitigate voltage deviations and active-power losses through coordinated control of large-scale wind/solar farms with shunt static var generators(SVGs).The model explicitly represents reactive-power regulation characteristics of doubly-fed wind turbines and PV inverters under real-time meteorological conditions,and quantifies SVG high-speed compensation capability,enabling seamless transition from localized VAR management to a globally coordinated strategy.An enhanced adaptive gain-sharing knowledge optimizer(AGSK-SD)integrates simulated annealing and diversity maintenance to autonomously tune voltage-control actions,renewable source reactive-power set-points,and SVG output.The algorithm adaptively modulates knowledge factors and ratios across search phases,performs SA-based fine-grained local exploitation,and periodically re-injects population diversity to prevent premature convergence.Comprehensive tests on IEEE 9-bus and 39-bus systems demonstrate AGSK-SD’s superiority over NSGA-II and MOPSO in hypervolume(HV),inverse generative distance(IGD),and spread metrics while maintaining acceptable computational burden.The method reduces network losses from 2.7191 to 2.15 MW(20.79%reduction)and from 15.1891 to 11.22 MW(26.16%reduction)in the 9-bus and 39-bus systems respectively.Simultaneously,the cumulative voltage-deviation index decreases from 0.0277 to 3.42×10^(−4) p.u.(98.77%reduction)in the 9-bus system,and from 0.0556 to 0.0107 p.u.(80.76%reduction)in the 39-bus system.These improvements demonstrate significant suppression of line losses and voltage fluctuations.Comparative analysis with traditional heuristic optimization algorithms confirms the superior performance of the proposed approach.展开更多
Conventional rolled Mg-Al alloy sheets typically exhibit strong basal textures that remain and may even strengthen after recrystallization annealing due to the preferential growth of basal-oriented grains,resulting in...Conventional rolled Mg-Al alloy sheets typically exhibit strong basal textures that remain and may even strengthen after recrystallization annealing due to the preferential growth of basal-oriented grains,resulting in poor formability at room temperature.Therefore,the knowledge of recrystallization and grain growth is critical for modifying textures of Mg-Al alloy sheets.The static recrystallization and texture evolution in a cold-rolled dilute Mg-1Al(wt.%)alloy during various annealed temperatures ranging from 300℃ to 450℃,have been investigated using the quasi in-situ electron backscatter diffraction(EBSD)method.The as-rolled Mg-1Al alloy shows a dominant basal texture,which weakens and broadens in the rolling direction(RD)during the subsequent annealing,accompanied by the formation of{1010}texture component.Particularly,the {1010} texture component is more pronounced after annealing at high temperatures.The quasi in-situ EBSD results show that recrystallized grains are mainly induced by shear bands,which exhibit a wide spectrum of orientations with c-axis tilt angles ranging 20°-45°from the normal direction(ND).Orientations of shear band-induced recrystallized grains are retained during the entire recrystallization process,resulting in a reduction in the texture intensity.Moreover,recrystallized grains belonging to the {1010}texture component grow preferentially compared to those with other orientations,which is attributed to low energy grain boundaries,especially grain boundaries with∼30°misorientation angles.Furthermore,the high temperature annealing facilitates the rapid growth of grain boundaries having a 30°misorientation angle,leading to the occurrence of distinct {1010} texture after annealing at 450℃ for 1 h.The results provide insights for texture modification of rare earth-free low-alloyed Mg alloys by controlling annealing parameters.展开更多
In recent decades,control performance monitoring(CPM)has experienced remarkable progress in research and industrial applications.While CPM research has been investigated using various benchmarks,the historical data be...In recent decades,control performance monitoring(CPM)has experienced remarkable progress in research and industrial applications.While CPM research has been investigated using various benchmarks,the historical data benchmark(HIS)has garnered the most attention due to its practicality and effectiveness.However,existing CPM reviews usually focus on the theoretical benchmark,and there is a lack of an in-depth review that thoroughly explores HIS-based methods.In this article,a comprehensive overview of HIS-based CPM is provided.First,we provide a novel static-dynamic perspective on data-level manifestations of control performance underlying typical controller capacities including regulation and servo:static and dynamic properties.The static property portrays time-independent variability in system output,and the dynamic property describes temporal behavior driven by closed-loop feedback.Accordingly,existing HIS-based CPM approaches and their intrinsic motivations are classified and analyzed from these two perspectives.Specifically,two mainstream solutions for CPM methods are summarized,including static analysis and dynamic analysis,which match data-driven techniques with actual controlling behavior.Furthermore,this paper also points out various opportunities and challenges faced in CPM for modern industry and provides promising directions in the context of artificial intelligence for inspiring future research.展开更多
Dispersion measure in an FRB’s signal is produced by the photons of the radio waves interacting with the free electrons in the IGM. In New Tired Light (NTL), redshifts are produced by the photons of light interacting...Dispersion measure in an FRB’s signal is produced by the photons of the radio waves interacting with the free electrons in the IGM. In New Tired Light (NTL), redshifts are produced by the photons of light interacting with these self-same electrons and so, one would expect a direct relationship between the DM of an FRB and the redshift of the host galaxy. However, workers in this field assume expansion and weight the DM by dividing it by the scale factor (1 + z) to allow for expansion. Once this weighting is removed, it was predicted back in 2016 (when the first FRB was localized) and later presented at a conference and published in the proceedings that, as more FRB’s were localized, a graph of DM versus ln(1 + z) would be a straight line of gradient (mec/2hre) or 7.32 × 1025 m−2 in SI units. The original paper had twenty-four data points but this has risen significantly to sixty-four useable FRB’s and so this corrigendum updates that paper so that all sixty-four are used. The data give a straight-line graph of gradient 7.12 × 1025 m−2, a difference of 3% from (mec/2hre) predicted nine years earlier.展开更多
This paper presents a vision-based navigation framework for micro air vehicles(MAVs)operating in confined warehouse environments.To address the trade-off between low localization accuracy in mapless methods and high c...This paper presents a vision-based navigation framework for micro air vehicles(MAVs)operating in confined warehouse environments.To address the trade-off between low localization accuracy in mapless methods and high computational demands in map-based approaches,the proposed system leverages topology-aware path guidance using monocular vision.Navigation is driven by a digital instruction format(DIF)that encodes both the path index and target junction,enabling autonomous navigation without environmental modifications.The framework comprises a cascaded perception-encoding-control pipeline.For structured paths,foreground pixel density trend analysis with sliding window smoothing for robust junction recognition,while lateral proportionalintegral-derivative(PID)control ensures accurate path tracking.For geometric trajectories,the control logic incorporates L-junction triggers,fixed-angle turns,and spatial yaw correction to accommodate sharp corners and curved segments.ROS-Gazebo simulations validate the method’s effectiveness,achieving up to 94.40%junction recognition accuracy(92.01%on average),trajectory tracking errors below 0.1 m,and terminal localization deviations under 0.2 m.These results validate the method’s accuracy,stability,and suitability for computationally constrained MAV platforms in warehouse automation.展开更多
The liquid Lane-Emden star is a free boundary problem of compressible EulerPoisson equation which describes motion of celestial bodies.This model admits a class of static solutions parametrized by its central density....The liquid Lane-Emden star is a free boundary problem of compressible EulerPoisson equation which describes motion of celestial bodies.This model admits a class of static solutions parametrized by its central density.According to Lam[9],when the central density is sufficiently small or the adiabatic constantγ∈[4/3,2],the static solutions are linearly stable.In this article,by constructing periodic solutions to the linearized equation,we prove that even though these solutions are linearly stable,they may not decay in time.Moreover we prove that if the sum of the internal energy and potential energy of this model has an minimizer,then it must be the spherically symmetric solution to the static equation,therefore demonstrating their stability from a variational point of view.展开更多
With the continuous development of artificial intelligence and machine learning techniques,there have been effective methods supporting the work of dermatologist in the field of skin cancer detection.However,object si...With the continuous development of artificial intelligence and machine learning techniques,there have been effective methods supporting the work of dermatologist in the field of skin cancer detection.However,object significant challenges have been presented in accurately segmenting melanomas in dermoscopic images due to the objects that could interfere human observations,such as bubbles and scales.To address these challenges,we propose a dual U-Net network framework for skin melanoma segmentation.In our proposed architecture,we introduce several innovative components that aim to enhance the performance and capabilities of the traditional U-Net.First,we establish a novel framework that links two simplified U-Nets,enabling more comprehensive information exchange and feature integration throughout the network.Second,after cascading the second U-Net,we introduce a skip connection between the decoder and encoder networks,and incorporate a modified receptive field block(MRFB),which is designed to capture multi-scale spatial information.Third,to further enhance the feature representation capabilities,we add a multi-path convolution block attention module(MCBAM)to the first two layers of the first U-Net encoding,and integrate a new squeeze-and-excitation(SE)mechanism with residual connections in the second U-Net.To illustrate the performance of our proposed model,we conducted comprehensive experiments on widely recognized skin datasets.On the ISIC-2017 dataset,the IoU value of our proposed model increased from 0.6406 to 0.6819 and the Dice coefficient increased from 0.7625 to 0.8023.On the ISIC-2018 dataset,the IoU value of proposed model also improved from 0.7138 to 0.7709,while the Dice coefficient increased from 0.8285 to 0.8665.Furthermore,the generalization experiments conducted on the jaw cyst dataset from Quzhou People’s Hospital further verified the outstanding segmentation performance of the proposed model.These findings collectively affirm the potential of our approach as a valuable tool in supporting clinical decision-making in the field of skin cancer detection,as well as advancing research in medical image analysis.展开更多
Due to their superior properties, the interest in nanostructures is increasing today in engineering. This study presents a new two-noded curved finite element for analyzing the in-plane static behaviors of curved nano...Due to their superior properties, the interest in nanostructures is increasing today in engineering. This study presents a new two-noded curved finite element for analyzing the in-plane static behaviors of curved nanobeams. Opposite to traditional curved finite elements developed by using approximate interpolation functions, the proposed curved finite element is developed by using exact analytical solutions. Although this approach was first introduced for analyzing the mechanical behaviors of macro-scale curved beams by adopting the local theory of elasticity, the exact analytical expressions used in this study were obtained from the solutions of governing equations that were expressed via the differential form of the nonlocal theory of elasticity. Therefore, the effects of shear strain and axial extension included in the analytical formulation are also inherited by the curved finite element developed here. The rigidity matrix and the consistent force vector are developed for a circular finite element. To demonstrate the applicability of the method, static analyses of various curved nanobeams subjected to different boundary conditions and loading scenarios are performed, and the obtained results are compared with the exact analytical ones. The presented study provides an accurate and low computational cost method for researchers to investigate the in-plane static behavior of curved nanobeams.展开更多
Rotary steering systems(RSSs)have been increasingly used to develop horizontal wells.A static push-the-bit RSS uses three hydraulic modules with varying degrees of expansion and contraction to achieve changes in the p...Rotary steering systems(RSSs)have been increasingly used to develop horizontal wells.A static push-the-bit RSS uses three hydraulic modules with varying degrees of expansion and contraction to achieve changes in the pushing force acting on the wellbore in different sizes and directions within a circular range,ultimately allowing the wellbore trajectory to be drilled in a predetermined direction.By analyzing its mathematical principles and the actual characteristics of the instrument,a vector force closed-loop control method,including steering and holding modes,was designed.The adjustment criteria for the three hydraulic modules are determined to achieve rapid adjustment of the vector force.The theoretical feasibility of the developed method was verified by comparing its results with the on-site application data of an imported rotary guidance system.展开更多
The flocculation behavior of carbon black (CB)-filled isoprene rubber (IR) nanocomposites was systematically investigated under both dynamic and static conditions to unravel the distinct mechanisms governing filler ne...The flocculation behavior of carbon black (CB)-filled isoprene rubber (IR) nanocomposites was systematically investigated under both dynamic and static conditions to unravel the distinct mechanisms governing filler network evolution.Under dynamic conditions,small oscillatory shear strains (0.1%) significantly enhanced filler particle motion,leading to pronounced agglomeration and a flocculation degree of about 4.3MPa at 145℃.In contrast,static flocculation exhibited a fundamentally different mechanism dominated by polymer chain dynamics,which is driven mainly by thermal activation.Radial distribution function (RDF) analysis of transmission electron microscopy (TEM) images revealed a slight decrease (2 nm) in the interparticle distance peak after static annealing at 100℃ for 7 h,indicating localized motion of CB particles.However,the overall filler network remained stable,with no significant agglomeration observed.The increase in bound rubber content from about 23% to 28% with rising temperature further confirmed the dominant role of polymer chain adsorption and interfacial reinforcement in static flocculation.These findings highlight the critical influence of external strain on filler network formation and provide new insights into the polymer-dominated mechanism of static flocculation.The results offer practical guidance for optimizing the storage and processing of rubber nanocomposites,particularly in applications where static flocculation during prolonged storage is a concern.展开更多
Purpose–This study solves the key problem that the static level monitoring is susceptible to temperature interference and affects the accuracy in slope instability/deformation monitoring.The purpose is to develop a r...Purpose–This study solves the key problem that the static level monitoring is susceptible to temperature interference and affects the accuracy in slope instability/deformation monitoring.The purpose is to develop a reliable temperature compensation method for the system,improve the accuracy of slope stability monitoring and provide support for improving the safety and safety monitoring of engineering spoil slope and other projects.Design/methodology/approach–Combined with theoretical analysis and experimental verification,the temperature compensation method is explored.The working principle of the hydrostatic leveling monitoring system is analyzed and the data processing formula,the temperature error calculation formula and the calculation formula for eliminating the error settlement value are derived.The temperature compensation method is established and verified by the field test of the engineering spoil slope which is disturbed by a debris flow.Findings–The experimental results show that this method can reduce the error of the static level monitoring system by about 40%.The field test shows that the fluctuation of slope settlement monitoring value is reduced after temperature compensation and the monitoring value is consistent with the actual situation,which has certain practicability.Originality/value–The originality of this study is to derive a theoretical formula for quantifying/eliminating temperature errors in static leveling and to establish a practical temperature compensation method.The accuracy of the system is improved,which provides a reference for slope stability monitoring under complex environment(especially railway geotechnical engineering)and promotes the development of precision monitoring technology.展开更多
The accuracy of the full-scale aircraft static tests is greatly influenced by the aircraft attitude.This paper proposes an aircraft attitude optimization method based on the characteristics of the test.The aim is to a...The accuracy of the full-scale aircraft static tests is greatly influenced by the aircraft attitude.This paper proposes an aircraft attitude optimization method based on the characteristics of the test.The aim is to address three typical problems of ttitude control in the full-scale aircraft static tests:(1)The coupling of rigid-body displacement and elastic deformation after large deformation,(2)the difficulty of characterizing the aircraft attitude by measurable structure,and(3)the insufficient adaptability of the center of gravity reference to complex loading conditions.The methodology involves the establishment of two observation coordinate systems,a ground coordinate system and an airframe coordinate system,and two deformation states,before and after airframe deformation.A subsequent analysis of the parameter changes of these two states under different coordinate systems is then undertaken,with the objective being to identify the key parameters affecting the attitude control accuracy of large deformation aircraft.Three optimization objective functions are established according to the test loading characteristics and the purpose of the test:(1)To minimize the full-scale aircraft loading angle error,(2)to minimize the full-scale aircraft loading additional load,and(3)to minimize the full-scale aircraft loading wing root additional bending moment.The optimization calculation results are obtained by using the particle swarm optimization algorithm,and the typical full-scale aircraft static test load condition of large passenger aircraft is taken as an example.The analysis of the results demonstrates that by customizing the measurable structure of the aircraft as the observation point for the aircraft attitude,and by obtaining the translational and rotational control parameters of the observation point during the test based on the optimization objective function,the results are reasonable,and the project can be implemented and used to control the aircraft's attitude more accurately in complex force test conditions.展开更多
To enhance the gas-damping effect and improve the bearing performance,a restricted layer is applied on the surface of aerostatic porous bearings.Based on the gas lubrication theory,a mathematical model of an aerostati...To enhance the gas-damping effect and improve the bearing performance,a restricted layer is applied on the surface of aerostatic porous bearings.Based on the gas lubrication theory,a mathematical model of an aerostatic porous bearing with a restricted layer is established,and two proportional coefficients,a permeability ratio δ and a thickness ratioγ,are proposed.Critical values of δ and γ are determined through sensitivity analyses of complex restriction-layer parameters.The static characteristics of aerostatic porous bearings with a restricted layer or an unrestricted layer are comparatively analyzed by using Fluent simulation.The results show that when δ≈0.005 and γ≈0.010,the load capacity and static stiffness of the restricted-layer aerostatic porous bearing are high;compared with the unrestricted-layer aerostatic porous bearing,the restricted-layer aerostatic porous bearing has a lower sensitivity to changes in the air supply area.The existence of the restricted layer not only enhances the throttling effect and reduces the mass flow rate,but also effectively improves the static stiffness of the bearing.展开更多
Understanding the reinforcement effect of the newly developed prestressed reinforcement components(PRCs)(a system composed of prestressed steel bars(PSBs),protective sleeves,lateral pressure plates(LPPs),and anchoring...Understanding the reinforcement effect of the newly developed prestressed reinforcement components(PRCs)(a system composed of prestressed steel bars(PSBs),protective sleeves,lateral pressure plates(LPPs),and anchoring elements)is technically significant for the rational design of prestressed subgrade.A three-dimensional finite element model was established and verified based on a novel static model test and utilized to systematically analyze the influence of prestress levels and reinforcement modes on the reinforcement effect of the subgrade.The results show that the PRCs provide additional confining pressure to the subgrade through the diffusion effect of the prestress,which can therefore effectively improve the service performance of the subgrade.Compared to the unreinforced conventional subgrades,the settlements of prestressreinforced subgrades are reduced.The settlement attenuation rate(Rs)near the LPPs is larger than that at the subgrade center,and increasing the prestress positively contributes to the stability of the subgrade structure.In the multi-row reinforcement mode,the reinforcement effect of PRCs can extend from the reinforced area to the unreinforced area.In addition,as the horizontal distance from the LPPs increases,the additional confining pressure converted by the PSBs and LPPs gradually diminishes when spreading to the core load bearing area of the subgrade,resulting in a decrease in the Rs.Under the singlerow reinforcement mode,PRCs can be strategically arranged according to the local areas where subgrade defects readily occurred or observed,to obtain the desired reinforcement effect.Moreover,excessive prestress should not be applied near the subgrade shoulder line to avoid the shear failure of the subgrade shoulder.PRCs can be flexibly used for preventing and treating various subgrade defects of newly constructed or existing railway lines,achieving targeted and classified prevention,and effectively improving the bearing performance and deformation resistance of the subgrade.The research results are instructive for further elucidating the prestress reinforcement effect of PRCs on railway subgrades.展开更多
Static disorder plays a crucial role in the electronic dynamics and spec-troscopy of complex molecular sys-tems.Traditionally,obtaining ob-servables averaged over static disor-der requires thousands of realiza-tions v...Static disorder plays a crucial role in the electronic dynamics and spec-troscopy of complex molecular sys-tems.Traditionally,obtaining ob-servables averaged over static disor-der requires thousands of realiza-tions via direct sampling of the dis-order distribution,leading to high computational costs.In this work,we extend the auxiliary degree-of-freedom based matrix product state(MPS)method to handle system-bath correlated thermal equilibrium initial states,which can capture static disorder effects using a one-shot quantum dynamical simulation.We validate the effectiveness of the extended method by computing the dipole-dipole time correlation function of the Holstein model relevant to the emission spectrum of molecular aggregates.Our results show that the one-shot method is very accu-rate with only a moderate increase in MPS bond dimension,thereby significantly reducing computational cost.Moreover,it enables the generation of a much larger number of samples than the conventional direct sampling method at negligible additional cost,thus reducing sta-tistical errors.This method provides a broadly useful tool for calculating equilibrium time cor-relation functions in system-bath coupled models with static disorder.展开更多
文摘In the modern era of ubiquitous and highly interconnected information technology,cybersecurity threats stemming from software code vulnerabilities have become increasingly severe,posing significant risks to the confidentiality,integrity,and availability of modern information systems.To enhance software code quality,enterprises often integrate static code analysis tools into Continuous Integration(CI) pipelines.However,the high rates of false positives and false negatives remain a challenge.The advent of large language models(LLMs),such as ChatGPT,presents a new opportunity to address these challenges.In this paper,we propose AI-SCDF,a framework that utilizes the custombuilt Nebula-Coder AI model for detecting and fixing code security issues in real time during the developer ' s personal build process.We construct a static code checking rule knowledge base through summarizing and classifying Common Weakness Enumeration(CWE) code security problems identified by security and quality assurance teams.The rule knowledge base is combined with CodeFuse-processed code contexts to serve as input for an AI code security detection microservice,which assists in identifying code quality and security issues.If any abnormalities are detected,they are addressed by an AI code security patching microservice,which alerts the developer and requests confirmation before committing the code into the repository.Experimental results show that our approach effectively improves code quality.We also develop a VS Code plugin for code alert detection and fix based on LLMs,which facilitates test shift-left and lowers the risk of software development.
基金supported by the National Natural Science Foundation of China(61904089)the Province Natural Science Foundation of Jiangsu(BK20190731).
文摘To improve the theoretical prediction accuracy of static mechanical quantities in MEMS cantilever beams for microwave power detection chips,a distributed static model is proposed based on the deflection equation.An analytical frame-work is established through the precise characterization of cantilever beam bending.The framework can accurately extract key electromechanical parameters,and the correlation between these parameters and geometric changes is systematically studied.Results show that the pull-in voltage increases with the gap but decreases with the length.The predicted pull-in voltage indi-cates a relative error of only 6.5%between the distributed static model and the simulation,which is significantly lower than that of the other two models.The overload power and sensitivity are also analyzed to facilitate performance trade-offs in chip design.The measured return loss varies between-66.46 and-10.56 dB over the 8-12 GHz frequency band,exhibiting a charac-teristic V-shaped trend.Moreover,the measured sensitivity of 66.5 fF/W closely matches the theoretical value of 69.3 fF/W,show-ing a relative error of 5.6%.These findings confirm that the distributed model outperforms the other two in terms of both accu-racy and physical realism,thereby providing important reference for the design of microwave power detection chips.
基金financially supported by the National Natural Science Foundation of China(No.52573053).
文摘Reactive compatibilization has been widely applied to enhance the compatibility of polymer blends,thereby improving their mechanical properties.However,it generally reduces the chain mobility and regularity,often leading to slower polymer crystallization.Here,we demonstrate that reactive compatibilization in poly(lactic acid)/poly(butylene adipate-co-terephthalate)(PLA/PBAT)blends unexpectedly promotes PLA matrix crystallization during injection molding,in contrast to the retarded kinetics observed in differential scanning calorimetry isothermal crystallization studies.The phase morphology,rheological behavior,and crystalline structure were systematically analyzed to elucidate markedly different crystallization kinetics under static and shear fields.The potential mechanism underlying crystallization enhancement is attributed to PBAT domain refinement and viscosity increase induced by reactive compatibilization,which,under shear flow,create favorable conditions for crystallization by enhancing PBAT fibril nucleation and retarding the relaxation of oriented PLA chains.This study offers new perspectives on the effect of reactive compatibilization on the polymer crystallization behavior.
文摘This study provides a new experimental framework to measure the static and dynamic electrical parameters for a solar panel of multiple cells.The study evaluates its static parameters,including its resultant diodes’saturation currents,diodes’ideality factors,series,and shunt resistances.Such parameters are essential to characterise the steady-state performance of a solar panel.Additionally,the dynamic parameters as the equivalent junction and diffusion capacitances are also experimentally measured.These parameters impact the performance of the panel at variable solar irradiance,temperature,and load conditions.A solar panel of 36 series-connected cells has been utilised in this research to undertake this experimental evaluation.This work addresses a gap in the recent literature regarding a full evaluation of the internal electrical parameters in a whole solar panel of multiple cells.Firstly,a dark experimental environment has been developed so that no influence from external light sources can affect the measurements being taken.The panel is then stimulated with different types of electrical stresses in various circuit configurations to measure the required static and dynamic parameters.For the solar panel under study,the series and shunt resistances per cell have been evaluated to be 18.91 mΩand 5.6 kΩ,respectively,while the junction and diffusion capacitances have shown direct and inverse relationships,respectively,with the applied voltage as expected.The outcomes of these experimental setups highlighted the importance of the developed comprehensive framework in this research to be employed to assess the quality of the solar panel and its real-time performance at variable operational conditions.
基金supported by the National Natural Science Foundation of China(Grant No.52174371)the National Key Research and Development Program of China(Grant No.2021YFB3501003)the Shaanxi Provincial Science and Technology Department Enterprise Joint Fund(Grant No.2021JLM-33).
文摘Single-pass and double-pass high-temperature deformation experiments were conducted on 40Cr10Si2Mo steel using a Gleeble-3500 thermal simulator.The static recrystallization(SRX)behavior and recrystallization mechanisms of 40Cr10Si2Mo steel were investigated under deformation temperatures of 900-1100℃,deformation strains of 10%,20%,and 30%,and inter-pass times of 1-120 s.A static recrystallization fraction model was developed.The results showed that the SRX volume fraction increased with higher deformation temperature,larger deformation amount,and longer inter-pass time,with the deformation temperature having the most significant effect on SRX.During the deformation process,different process parameters led to different internal deformation mechanisms of the material.Static recovery and continuous static recrystallization(CSRX)dominated deformation at lower temperatures through progressive lattice rotation.In comparison,at higher temperatures,the deformation mechanism was dominated by CSRX and discontinuous static recrystallization(DSRX).The nucleation mechanisms of the SRX process were grain boundary bulging nucleation and subgrain merging nucleation,with grain boundary bulging present under all conditions.Subgrain merging nucleation could provide an additional nucleation mode at lower deformation temperatures or lower deformation amounts.Based on the traditional Avarmi equation,a modified model coefficient was used to establish the SRX kinetic model for 40Cr10Si2Mo steel.The linear correlation coefficient R^(2) between the predicted and experimental static recrystallization volume fraction was 0.96702,indicating high prediction accuracy.
基金supported by Yunnan Power Grid Co.,Ltd.Science and Technology Project:Research and application of key technologies for graphical-based power grid accident reconstruction and simulation(YNKJXM20240333).
文摘An optimized volt-ampere reactive(VAR)control framework is proposed for transmission-level power systems to simultaneously mitigate voltage deviations and active-power losses through coordinated control of large-scale wind/solar farms with shunt static var generators(SVGs).The model explicitly represents reactive-power regulation characteristics of doubly-fed wind turbines and PV inverters under real-time meteorological conditions,and quantifies SVG high-speed compensation capability,enabling seamless transition from localized VAR management to a globally coordinated strategy.An enhanced adaptive gain-sharing knowledge optimizer(AGSK-SD)integrates simulated annealing and diversity maintenance to autonomously tune voltage-control actions,renewable source reactive-power set-points,and SVG output.The algorithm adaptively modulates knowledge factors and ratios across search phases,performs SA-based fine-grained local exploitation,and periodically re-injects population diversity to prevent premature convergence.Comprehensive tests on IEEE 9-bus and 39-bus systems demonstrate AGSK-SD’s superiority over NSGA-II and MOPSO in hypervolume(HV),inverse generative distance(IGD),and spread metrics while maintaining acceptable computational burden.The method reduces network losses from 2.7191 to 2.15 MW(20.79%reduction)and from 15.1891 to 11.22 MW(26.16%reduction)in the 9-bus and 39-bus systems respectively.Simultaneously,the cumulative voltage-deviation index decreases from 0.0277 to 3.42×10^(−4) p.u.(98.77%reduction)in the 9-bus system,and from 0.0556 to 0.0107 p.u.(80.76%reduction)in the 39-bus system.These improvements demonstrate significant suppression of line losses and voltage fluctuations.Comparative analysis with traditional heuristic optimization algorithms confirms the superior performance of the proposed approach.
基金by National Natural Science Foundation of China(Nos.52271103,52334010 and 52271031)Jilin Scientific and Technological Development Program(Nos.20220301026GX,20210201115GX and 20210301041GX).
文摘Conventional rolled Mg-Al alloy sheets typically exhibit strong basal textures that remain and may even strengthen after recrystallization annealing due to the preferential growth of basal-oriented grains,resulting in poor formability at room temperature.Therefore,the knowledge of recrystallization and grain growth is critical for modifying textures of Mg-Al alloy sheets.The static recrystallization and texture evolution in a cold-rolled dilute Mg-1Al(wt.%)alloy during various annealed temperatures ranging from 300℃ to 450℃,have been investigated using the quasi in-situ electron backscatter diffraction(EBSD)method.The as-rolled Mg-1Al alloy shows a dominant basal texture,which weakens and broadens in the rolling direction(RD)during the subsequent annealing,accompanied by the formation of{1010}texture component.Particularly,the {1010} texture component is more pronounced after annealing at high temperatures.The quasi in-situ EBSD results show that recrystallized grains are mainly induced by shear bands,which exhibit a wide spectrum of orientations with c-axis tilt angles ranging 20°-45°from the normal direction(ND).Orientations of shear band-induced recrystallized grains are retained during the entire recrystallization process,resulting in a reduction in the texture intensity.Moreover,recrystallized grains belonging to the {1010}texture component grow preferentially compared to those with other orientations,which is attributed to low energy grain boundaries,especially grain boundaries with∼30°misorientation angles.Furthermore,the high temperature annealing facilitates the rapid growth of grain boundaries having a 30°misorientation angle,leading to the occurrence of distinct {1010} texture after annealing at 450℃ for 1 h.The results provide insights for texture modification of rare earth-free low-alloyed Mg alloys by controlling annealing parameters.
基金supported in part by the National Natural Science Foundation of China(62125306)Zhejiang Key Research and Development Project(2024C01163)the State Key Laboratory of Industrial Control Technology,China(ICT2024A06)
文摘In recent decades,control performance monitoring(CPM)has experienced remarkable progress in research and industrial applications.While CPM research has been investigated using various benchmarks,the historical data benchmark(HIS)has garnered the most attention due to its practicality and effectiveness.However,existing CPM reviews usually focus on the theoretical benchmark,and there is a lack of an in-depth review that thoroughly explores HIS-based methods.In this article,a comprehensive overview of HIS-based CPM is provided.First,we provide a novel static-dynamic perspective on data-level manifestations of control performance underlying typical controller capacities including regulation and servo:static and dynamic properties.The static property portrays time-independent variability in system output,and the dynamic property describes temporal behavior driven by closed-loop feedback.Accordingly,existing HIS-based CPM approaches and their intrinsic motivations are classified and analyzed from these two perspectives.Specifically,two mainstream solutions for CPM methods are summarized,including static analysis and dynamic analysis,which match data-driven techniques with actual controlling behavior.Furthermore,this paper also points out various opportunities and challenges faced in CPM for modern industry and provides promising directions in the context of artificial intelligence for inspiring future research.
文摘Dispersion measure in an FRB’s signal is produced by the photons of the radio waves interacting with the free electrons in the IGM. In New Tired Light (NTL), redshifts are produced by the photons of light interacting with these self-same electrons and so, one would expect a direct relationship between the DM of an FRB and the redshift of the host galaxy. However, workers in this field assume expansion and weight the DM by dividing it by the scale factor (1 + z) to allow for expansion. Once this weighting is removed, it was predicted back in 2016 (when the first FRB was localized) and later presented at a conference and published in the proceedings that, as more FRB’s were localized, a graph of DM versus ln(1 + z) would be a straight line of gradient (mec/2hre) or 7.32 × 1025 m−2 in SI units. The original paper had twenty-four data points but this has risen significantly to sixty-four useable FRB’s and so this corrigendum updates that paper so that all sixty-four are used. The data give a straight-line graph of gradient 7.12 × 1025 m−2, a difference of 3% from (mec/2hre) predicted nine years earlier.
基金supported by the Fundamental Research Grant Scheme(FRGS)(No.FRGS/1/2024/TK04/USM/02/3)funded by the Malaysian Ministry of Higher Education(MOHE).
文摘This paper presents a vision-based navigation framework for micro air vehicles(MAVs)operating in confined warehouse environments.To address the trade-off between low localization accuracy in mapless methods and high computational demands in map-based approaches,the proposed system leverages topology-aware path guidance using monocular vision.Navigation is driven by a digital instruction format(DIF)that encodes both the path index and target junction,enabling autonomous navigation without environmental modifications.The framework comprises a cascaded perception-encoding-control pipeline.For structured paths,foreground pixel density trend analysis with sliding window smoothing for robust junction recognition,while lateral proportionalintegral-derivative(PID)control ensures accurate path tracking.For geometric trajectories,the control logic incorporates L-junction triggers,fixed-angle turns,and spatial yaw correction to accommodate sharp corners and curved segments.ROS-Gazebo simulations validate the method’s effectiveness,achieving up to 94.40%junction recognition accuracy(92.01%on average),trajectory tracking errors below 0.1 m,and terminal localization deviations under 0.2 m.These results validate the method’s accuracy,stability,and suitability for computationally constrained MAV platforms in warehouse automation.
基金supported by the National Key R&D Program of China(2021YFA1001700)the National Science Foundation of China(12426203,12221001)。
文摘The liquid Lane-Emden star is a free boundary problem of compressible EulerPoisson equation which describes motion of celestial bodies.This model admits a class of static solutions parametrized by its central density.According to Lam[9],when the central density is sufficiently small or the adiabatic constantγ∈[4/3,2],the static solutions are linearly stable.In this article,by constructing periodic solutions to the linearized equation,we prove that even though these solutions are linearly stable,they may not decay in time.Moreover we prove that if the sum of the internal energy and potential energy of this model has an minimizer,then it must be the spherically symmetric solution to the static equation,therefore demonstrating their stability from a variational point of view.
基金funded by Zhejiang Basic Public Welfare Research Project,grant number LZY24E060001supported by Guangzhou Development Zone Science and Technology(2021GH10,2020GH10,2023GH02)+1 种基金the University of Macao(MYRG2022-00271-FST)the Science and Technology Development Fund(FDCT)of Macao(0032/2022/A).
文摘With the continuous development of artificial intelligence and machine learning techniques,there have been effective methods supporting the work of dermatologist in the field of skin cancer detection.However,object significant challenges have been presented in accurately segmenting melanomas in dermoscopic images due to the objects that could interfere human observations,such as bubbles and scales.To address these challenges,we propose a dual U-Net network framework for skin melanoma segmentation.In our proposed architecture,we introduce several innovative components that aim to enhance the performance and capabilities of the traditional U-Net.First,we establish a novel framework that links two simplified U-Nets,enabling more comprehensive information exchange and feature integration throughout the network.Second,after cascading the second U-Net,we introduce a skip connection between the decoder and encoder networks,and incorporate a modified receptive field block(MRFB),which is designed to capture multi-scale spatial information.Third,to further enhance the feature representation capabilities,we add a multi-path convolution block attention module(MCBAM)to the first two layers of the first U-Net encoding,and integrate a new squeeze-and-excitation(SE)mechanism with residual connections in the second U-Net.To illustrate the performance of our proposed model,we conducted comprehensive experiments on widely recognized skin datasets.On the ISIC-2017 dataset,the IoU value of our proposed model increased from 0.6406 to 0.6819 and the Dice coefficient increased from 0.7625 to 0.8023.On the ISIC-2018 dataset,the IoU value of proposed model also improved from 0.7138 to 0.7709,while the Dice coefficient increased from 0.8285 to 0.8665.Furthermore,the generalization experiments conducted on the jaw cyst dataset from Quzhou People’s Hospital further verified the outstanding segmentation performance of the proposed model.These findings collectively affirm the potential of our approach as a valuable tool in supporting clinical decision-making in the field of skin cancer detection,as well as advancing research in medical image analysis.
基金supported by Scientific Research Projects Department of Istanbul Technical University.Project Number:MGA-2018-41546.Grant receiver:E.T.
文摘Due to their superior properties, the interest in nanostructures is increasing today in engineering. This study presents a new two-noded curved finite element for analyzing the in-plane static behaviors of curved nanobeams. Opposite to traditional curved finite elements developed by using approximate interpolation functions, the proposed curved finite element is developed by using exact analytical solutions. Although this approach was first introduced for analyzing the mechanical behaviors of macro-scale curved beams by adopting the local theory of elasticity, the exact analytical expressions used in this study were obtained from the solutions of governing equations that were expressed via the differential form of the nonlocal theory of elasticity. Therefore, the effects of shear strain and axial extension included in the analytical formulation are also inherited by the curved finite element developed here. The rigidity matrix and the consistent force vector are developed for a circular finite element. To demonstrate the applicability of the method, static analyses of various curved nanobeams subjected to different boundary conditions and loading scenarios are performed, and the obtained results are compared with the exact analytical ones. The presented study provides an accurate and low computational cost method for researchers to investigate the in-plane static behavior of curved nanobeams.
基金supported by the Opening Foundation of China National Logging Corporation(CNLC20229C06)the China Petroleum Technical Service Corporation's science project'Development and application of 475 rotary steering system'(2024T-001001)。
文摘Rotary steering systems(RSSs)have been increasingly used to develop horizontal wells.A static push-the-bit RSS uses three hydraulic modules with varying degrees of expansion and contraction to achieve changes in the pushing force acting on the wellbore in different sizes and directions within a circular range,ultimately allowing the wellbore trajectory to be drilled in a predetermined direction.By analyzing its mathematical principles and the actual characteristics of the instrument,a vector force closed-loop control method,including steering and holding modes,was designed.The adjustment criteria for the three hydraulic modules are determined to achieve rapid adjustment of the vector force.The theoretical feasibility of the developed method was verified by comparing its results with the on-site application data of an imported rotary guidance system.
基金supported by the National Natural Science Foundation of China(No.52293471)National Key R&D Program of China(No.2022YFB3707303).
文摘The flocculation behavior of carbon black (CB)-filled isoprene rubber (IR) nanocomposites was systematically investigated under both dynamic and static conditions to unravel the distinct mechanisms governing filler network evolution.Under dynamic conditions,small oscillatory shear strains (0.1%) significantly enhanced filler particle motion,leading to pronounced agglomeration and a flocculation degree of about 4.3MPa at 145℃.In contrast,static flocculation exhibited a fundamentally different mechanism dominated by polymer chain dynamics,which is driven mainly by thermal activation.Radial distribution function (RDF) analysis of transmission electron microscopy (TEM) images revealed a slight decrease (2 nm) in the interparticle distance peak after static annealing at 100℃ for 7 h,indicating localized motion of CB particles.However,the overall filler network remained stable,with no significant agglomeration observed.The increase in bound rubber content from about 23% to 28% with rising temperature further confirmed the dominant role of polymer chain adsorption and interfacial reinforcement in static flocculation.These findings highlight the critical influence of external strain on filler network formation and provide new insights into the polymer-dominated mechanism of static flocculation.The results offer practical guidance for optimizing the storage and processing of rubber nanocomposites,particularly in applications where static flocculation during prolonged storage is a concern.
基金funded by the Scientific Research Project of China Academy of Railway Sciences Group Co.,Ltd(No.2024YJ332 and No.2024QT005)Scientific Research Special Project of China State Railway Group Co.,Ltd(No.TICSTR-2024-Ⅳ-007).
文摘Purpose–This study solves the key problem that the static level monitoring is susceptible to temperature interference and affects the accuracy in slope instability/deformation monitoring.The purpose is to develop a reliable temperature compensation method for the system,improve the accuracy of slope stability monitoring and provide support for improving the safety and safety monitoring of engineering spoil slope and other projects.Design/methodology/approach–Combined with theoretical analysis and experimental verification,the temperature compensation method is explored.The working principle of the hydrostatic leveling monitoring system is analyzed and the data processing formula,the temperature error calculation formula and the calculation formula for eliminating the error settlement value are derived.The temperature compensation method is established and verified by the field test of the engineering spoil slope which is disturbed by a debris flow.Findings–The experimental results show that this method can reduce the error of the static level monitoring system by about 40%.The field test shows that the fluctuation of slope settlement monitoring value is reduced after temperature compensation and the monitoring value is consistent with the actual situation,which has certain practicability.Originality/value–The originality of this study is to derive a theoretical formula for quantifying/eliminating temperature errors in static leveling and to establish a practical temperature compensation method.The accuracy of the system is improved,which provides a reference for slope stability monitoring under complex environment(especially railway geotechnical engineering)and promotes the development of precision monitoring technology.
基金supported in part by the National Specialized Research Project(No.XXZ3-XX21-3).
文摘The accuracy of the full-scale aircraft static tests is greatly influenced by the aircraft attitude.This paper proposes an aircraft attitude optimization method based on the characteristics of the test.The aim is to address three typical problems of ttitude control in the full-scale aircraft static tests:(1)The coupling of rigid-body displacement and elastic deformation after large deformation,(2)the difficulty of characterizing the aircraft attitude by measurable structure,and(3)the insufficient adaptability of the center of gravity reference to complex loading conditions.The methodology involves the establishment of two observation coordinate systems,a ground coordinate system and an airframe coordinate system,and two deformation states,before and after airframe deformation.A subsequent analysis of the parameter changes of these two states under different coordinate systems is then undertaken,with the objective being to identify the key parameters affecting the attitude control accuracy of large deformation aircraft.Three optimization objective functions are established according to the test loading characteristics and the purpose of the test:(1)To minimize the full-scale aircraft loading angle error,(2)to minimize the full-scale aircraft loading additional load,and(3)to minimize the full-scale aircraft loading wing root additional bending moment.The optimization calculation results are obtained by using the particle swarm optimization algorithm,and the typical full-scale aircraft static test load condition of large passenger aircraft is taken as an example.The analysis of the results demonstrates that by customizing the measurable structure of the aircraft as the observation point for the aircraft attitude,and by obtaining the translational and rotational control parameters of the observation point during the test based on the optimization objective function,the results are reasonable,and the project can be implemented and used to control the aircraft's attitude more accurately in complex force test conditions.
文摘To enhance the gas-damping effect and improve the bearing performance,a restricted layer is applied on the surface of aerostatic porous bearings.Based on the gas lubrication theory,a mathematical model of an aerostatic porous bearing with a restricted layer is established,and two proportional coefficients,a permeability ratio δ and a thickness ratioγ,are proposed.Critical values of δ and γ are determined through sensitivity analyses of complex restriction-layer parameters.The static characteristics of aerostatic porous bearings with a restricted layer or an unrestricted layer are comparatively analyzed by using Fluent simulation.The results show that when δ≈0.005 and γ≈0.010,the load capacity and static stiffness of the restricted-layer aerostatic porous bearing are high;compared with the unrestricted-layer aerostatic porous bearing,the restricted-layer aerostatic porous bearing has a lower sensitivity to changes in the air supply area.The existence of the restricted layer not only enhances the throttling effect and reduces the mass flow rate,but also effectively improves the static stiffness of the bearing.
基金supported by the National Natural Science Foundation of China(Grant Nos.51978672 and 52308335)the Natural Science Funding of Hunan Province(Grant No.2023JJ41054)the Natural Science Research Project of Anhui Educational Committee(Grant No.2023AH051170)。
文摘Understanding the reinforcement effect of the newly developed prestressed reinforcement components(PRCs)(a system composed of prestressed steel bars(PSBs),protective sleeves,lateral pressure plates(LPPs),and anchoring elements)is technically significant for the rational design of prestressed subgrade.A three-dimensional finite element model was established and verified based on a novel static model test and utilized to systematically analyze the influence of prestress levels and reinforcement modes on the reinforcement effect of the subgrade.The results show that the PRCs provide additional confining pressure to the subgrade through the diffusion effect of the prestress,which can therefore effectively improve the service performance of the subgrade.Compared to the unreinforced conventional subgrades,the settlements of prestressreinforced subgrades are reduced.The settlement attenuation rate(Rs)near the LPPs is larger than that at the subgrade center,and increasing the prestress positively contributes to the stability of the subgrade structure.In the multi-row reinforcement mode,the reinforcement effect of PRCs can extend from the reinforced area to the unreinforced area.In addition,as the horizontal distance from the LPPs increases,the additional confining pressure converted by the PSBs and LPPs gradually diminishes when spreading to the core load bearing area of the subgrade,resulting in a decrease in the Rs.Under the singlerow reinforcement mode,PRCs can be strategically arranged according to the local areas where subgrade defects readily occurred or observed,to obtain the desired reinforcement effect.Moreover,excessive prestress should not be applied near the subgrade shoulder line to avoid the shear failure of the subgrade shoulder.PRCs can be flexibly used for preventing and treating various subgrade defects of newly constructed or existing railway lines,achieving targeted and classified prevention,and effectively improving the bearing performance and deformation resistance of the subgrade.The research results are instructive for further elucidating the prestress reinforcement effect of PRCs on railway subgrades.
基金supported by the National Natural Science Foundation of China(No.22273005 and No.22422301)the Innovation Program for Quantum Science and Technology(No.2023ZD0300200)+1 种基金the National Security Academic Foundation(No.U2330201)the Fundamental Research Funds for the Central Universities.
文摘Static disorder plays a crucial role in the electronic dynamics and spec-troscopy of complex molecular sys-tems.Traditionally,obtaining ob-servables averaged over static disor-der requires thousands of realiza-tions via direct sampling of the dis-order distribution,leading to high computational costs.In this work,we extend the auxiliary degree-of-freedom based matrix product state(MPS)method to handle system-bath correlated thermal equilibrium initial states,which can capture static disorder effects using a one-shot quantum dynamical simulation.We validate the effectiveness of the extended method by computing the dipole-dipole time correlation function of the Holstein model relevant to the emission spectrum of molecular aggregates.Our results show that the one-shot method is very accu-rate with only a moderate increase in MPS bond dimension,thereby significantly reducing computational cost.Moreover,it enables the generation of a much larger number of samples than the conventional direct sampling method at negligible additional cost,thus reducing sta-tistical errors.This method provides a broadly useful tool for calculating equilibrium time cor-relation functions in system-bath coupled models with static disorder.
