This study focuses on a new and high-efficiency approach in a unified sense of accurately simulating strength-degrading effects for geomaterials,including non-symmetric hardening-to-softening effects in tension and co...This study focuses on a new and high-efficiency approach in a unified sense of accurately simulating strength-degrading effects for geomaterials,including non-symmetric hardening-to-softening effects in tension and compression as well as non-symmetric tensile and compressive stiffness-degrading effects during unloading.It is intended to bypass both modeling and numerical complexities involved in existing approaches.To this goal,new elastoplastic equations are established with new numerical techniques.With a decoupling technique of treating tension-compression asymmetry,the foregoing complex effects are automatically incorporated as inherent response features of the new elastoplastic equations,thus bypassing usual modeling complexities.A new numerical technique of renormalizing piecewise spline functions is introduced to resolve the central yet tough issue of obtaining accurate and unified expressions for the tensile and compressive strength functions,thus bypassing usual numerical complexities and uncertainties in treating numerous unknown parameters and multiple ad hoc criteria.As such,the new approach is not only of wide applicability for various geomaterials but also of high computational efficiency with no more than three adjustable parameters.Toward validating the efficacy of the new approach,numerical examples for granite,salt rock,and sandstone-concrete combined body as well as plain concrete,high-performance concrete,and ultrahigh-performance concrete are presented by comparing model predictions with multiple data sets for strength-degrading effects in tension and compression.展开更多
The transient phenomena of re-oxidation and slag entrapment occurring in the tundish during the ladle change-over process have been proven detrimental to clean steel production.Therefore,an unsteady three-phase turbul...The transient phenomena of re-oxidation and slag entrapment occurring in the tundish during the ladle change-over process have been proven detrimental to clean steel production.Therefore,an unsteady three-phase turbulence model,coupling velocity,temperature,and phase field was established to study the effect of the ladle shroud immersion depth on the slag eye formation,slag entrainment,slag dragging,air dragging,and flow characteristics during the ladle change-over process of a two-strand tundish.The results showed that reducing the immersion depth decreases the high-velocity region area under the slag layer in the quasi-steady process.During the emptying stage,as the molten bath level gradually decreases,the outlet temperature exhibits a trend of initially decreasing and subsequently increasing across all three shroud immersion depths.However,under a 210 mm shroud immersion depth,molten slag and air are dragged into the shroud,forming slag droplets and causing significant fluctuations,with a maximum scalar velocity of 0.0764 m/s at the monitoring point.In the filling stage,air and molten slag are dragged into the molten bath,forming bubbles and slag droplets at an immersion depth of 210 mm.Bubbles are observed within the molten slag layer,which can readily cause an emulsification phenomenon,making it easier to be dragged as slag droplets.Additionally,the slag eye area measured under 210 mm immersion depth at 45 s is 0.303 m^(2),while the maximum scalar velocity of 2.4259 m/s is detected at 12 s.At an immersion depth of 360 mm,the average area of the slag eye is minimized to 0.06268 m2,with corresponding variances of 0.006753,representing the optimal immersion depth.展开更多
Early fault detection for spiral bevel gears is crucial to ensure normal operation and prevent accidents.The harmonic components,excited by the time-varying mesh stiffness,always appear in measured vibration signal.Ho...Early fault detection for spiral bevel gears is crucial to ensure normal operation and prevent accidents.The harmonic components,excited by the time-varying mesh stiffness,always appear in measured vibration signal.How to extract the periodical impulses that indicate gear localized fault buried in the intensive noise and interfered by harmonics is a challenging task.In this paper,a novel Periodical Sparse-Assisted Decoupling(PSAD)method is proposed as an optimization problem to extract fault feature from noisy vibration signal.The PSAD method decouples the impulsive fault feature and harmonic components based on the sparse representation method.The sparsity within and across groups property and the periodicity of the fault feature are incorporated into the regularizer as the prior information.The nonconvex penalty is employed to highlight the sparsity of fault features.Meanwhile,the weight factor based on2norm of each group is constructed to strengthen the amplitude of fault feature.An iterative algorithm with Majorization-Minimization(MM)is derived to solve the optimization problem.Simulation study and experimental analysis confirm the performance of the proposed PSAD method in extracting and enhancing defect impulses from noisy signal.The suggested method surpasses other comparative methods in extracting and enhancing fault features.展开更多
Taking three-phase electrode adjusting system of submerged arc furnace as study object which has nonlinear, time-variant, multivariable and strong coupling features, a neural adaptive PSD(proportion, sum and different...Taking three-phase electrode adjusting system of submerged arc furnace as study object which has nonlinear, time-variant, multivariable and strong coupling features, a neural adaptive PSD(proportion, sum and differential) dispersive decoupling controller was developed by combining neural adaptive PSD algorithm with dispersive decoupling network. In this work, the production technology process and control difficulties of submerged arc furnace were simply introduced, the necessity of establishing a neural adaptive PSD dispersive decoupling controller was discussed, the design method and the implementation steps of the controller are expounded in detail, and the block diagram of the controlled system is presented. By comparison with experimental results of the conventional PID controller and the adaptive PSD controller, the decoupling ability, adaptive ability, self-learning ability and robustness of the neural adaptive PSD dispersive decoupling controller have been testified effectively. The controller is applicable to the three-phase electrode adjusting system of submerged arc furnace, and it will play an important role for achieving the power balance of three-phrase electrodes, saving energy and reducing consumption in the process of smelting.展开更多
Human skin exhibits a remarkable capability to perceive contact forces and environmental temperatures,providing complex information that is essential for its subtle control.Despite recent advancements in soft tactile ...Human skin exhibits a remarkable capability to perceive contact forces and environmental temperatures,providing complex information that is essential for its subtle control.Despite recent advancements in soft tactile sensors,accurately decoupling signals—specifically separating forces from directional orientation and temperature—remains a challenge thus resulting in failure to meet the advanced application requirements of robots.This study proposes,F3T,a multilayer soft sensor unit designed to achieve isolated measurements and mathematical decoupling of normal pressure,omnidirectional tangential forces,and temperature.We developed a circular coaxial magnetic film featuring a floating mount multilayer capacitor that facilitated the physical decoupling of normal and tangential forces in all directions.Additionally,we incorporated an ion gel-based temperature-sensing film into the tactile sensor.The proposed sensor was resilient to external pressures and deformations,and could measure temperature and significantly eliminate capacitor errors induced by environmental temperature changes.In conclusion,our novel design allowed for the decoupled measurement of multiple signals,laying the foundation for advancements in high-level robotic motion control,autonomous decision-making,and task planning.展开更多
To achieve high power rating and low current harmonics of motor drive,this paper develops a dual three-phase open-winding permanent magnet synchronous motor(DTP-OW-PMSM)drive with the DC-link voltage ratio of 2:1:1.Ba...To achieve high power rating and low current harmonics of motor drive,this paper develops a dual three-phase open-winding permanent magnet synchronous motor(DTP-OW-PMSM)drive with the DC-link voltage ratio of 2:1:1.Based on this topology,this paper proposes a DTP four-level space vector pulse width modulation(DTP-FL SVPWM)strategy.First,two identical three-phase four-level space vector diagrams are constructed and divided.Then,three adjacent vectors nearest to the reference vector in each diagram are selected for the vector synthesis to guarantee high modulation precision and low switching frequency.Furthermore,to avoid the modulation error caused by the voltage deviation,the proposed DTP-FL SVPWM strategy is further optimized through unified duty ratio compensation(UDRC).The effectiveness of the proposed strategy is verified through experiments.展开更多
The elimination of the vertical tail in tailless aircraft results in a significant decrease in heading static stability,causing substantial coupling among the three control channels.In addition,in specific operational...The elimination of the vertical tail in tailless aircraft results in a significant decrease in heading static stability,causing substantial coupling among the three control channels.In addition,in specific operational scenarios,the tailless aircraft is prone to electromagnetic interference,leading to the generation of high-frequency noise and consequently compromising their control performance.To address these issues,a decoupling control method based on a fractional-order error extended state observer(FOEESO)is proposed.A nonlinear model of a tailless aircraft with thrust vectoring capabilities is first developed.The decoupling control design for the three control channels is then implemented using FOEESO,with the asymptotic convergence conditions outlined.The proposed method is evaluated through simulations and compared to coupled control and linear extended state observer(LESO)techniques.Numerical simulations demonstrate that the FOEESO-based control methodology achieves effective decoupling,exhibiting 6.9%and 11.7%reductions in integral absolute error(IAE)relative to LESO under nominal operational conditions and critical fault scenarios,respectively.These improvements thereby highlight FOEESO’s capability to enhance closed-loop stability and tracking precision in tailless aircraft control systems.展开更多
Planar positioning systems are widely utilized in micro and nano applications.The challenges in modeling and control of XYΘflexure-based mechanisms include hysteresis of the piezoelectric actuators,couplings among th...Planar positioning systems are widely utilized in micro and nano applications.The challenges in modeling and control of XYΘflexure-based mechanisms include hysteresis of the piezoelectric actuators,couplings among the input axes,and coupled linear and angular motions of the end effector.This paper presents an inverse hysteresis-coupling hybrid model to account for such hysteresis and couplings.First,a specially designed kinematic chain is adopted to transfer the pose of the end effector into the linear motions at three prismatic joints.Second,an inverse hysteresis-coupling hybrid model is developed to linearize and decouple the system via a multilayer feedforward neural network.A fractional-order PID controller is also integrated to improve the motion accuracy of the overall system.Experimental results demonstrate that the proposed method can accurately control the motion of the end effector with improved accuracy and robustness.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
Exploring the factors driving the decoupling of China’s sulfur dioxide(SO_(2))emissions from economic growth(DEI)is crucial for achieving sustainable development.By analyzing the decoupling indicators and driving fac...Exploring the factors driving the decoupling of China’s sulfur dioxide(SO_(2))emissions from economic growth(DEI)is crucial for achieving sustainable development.By analyzing the decoupling indicators and driving factors at both the generation and treatment stages of SO_(2),more effective targeted mitigation strategies can be developed.We employ the Tapio decoupling model and propose a two-stage method to examine the decoupling issues related to SO_(2).Our findings indicate that:①DEI shows a steady and significant improvement,with SO_(2)emission intensity identified as the primary driver.②for the decoupling of economic growth and SO_(2)generation,energy scale serves as the largest stimulator,while the effect of energy intensity changes from negative to positive,and pollution intensity is first positive and then negative.③For the decoupling of SO_(2)generation and SO_(2)removal,treatment efficiency leads as the largest promoter,followed by treatment intensity.Based on these results,this study recommends that China focuses more on enhancing clean energy utilization and the effectiveness of treatment processes.展开更多
The growing demand for efficient high-power switching power supplies has spurred interest in advanced topologies.The three-phase VIENNA converter stands out for its high power factor,simplified structure,and robust pe...The growing demand for efficient high-power switching power supplies has spurred interest in advanced topologies.The three-phase VIENNA converter stands out for its high power factor,simplified structure,and robust performance.Current research focuses on its operational principles,control strategies,and behavior under various load conditions.Key considerations include component selection,thermal management,and EMI/EMC optimization.This topology finds applications across renewable energy systems,industrial equipment,telecommunications,and electric vehicle charging infrastructures.Comparative analyses with alternative topologies and cost-benefit evaluations are also addressed.Future developments are expected to emphasize the integration of wide-bandgap devices and advancements in digital control techniques to further enhance efficiency and system performance.展开更多
The progress from intelligent interactions requires electronic skin(E-skin)to shift from single-functional perception to multisensory capabilities.However,the intuitive and interference-free reading of multiple sensor...The progress from intelligent interactions requires electronic skin(E-skin)to shift from single-functional perception to multisensory capabilities.However,the intuitive and interference-free reading of multiple sensory signals without involving complex algorithms is a critical challenge.Herein,we propose a flexible multisensory E-skin by developing a highly homogeneous dispersion of BaTiO_(3)nanoparticles in polydimethylsiloxane dielectric layer.The E-skin is sensitive to externally applied pressure as well as temperature and can distinguish dual synergetic stimuli by the time decoupling effect.The pressure and temperature perception was achieved in an individual device,which greatly reduced the structural complexity compared with multifunctional integrated devices.The sensitivity of E-skin for pressure detection is as high as 0.0724 kPa^(−1)and the detection range reaches as wide as 15.625-10 MPa.The sensitivity to temperature detection is as high as−1.34℃^(−1)and the detection range reaches 20-200℃.More importantly,by equipping with a multilayer neural network,the evolution from tactile perception to advanced intelligent tactile cognition is demonstrated.展开更多
Against the backdrop of regional coordinated development and China’s“dual carbon”strategic objectives,the Beijing-Tianjin-Hebei(BTH)region faces an urgent need to transition fromits traditional economic growth mode...Against the backdrop of regional coordinated development and China’s“dual carbon”strategic objectives,the Beijing-Tianjin-Hebei(BTH)region faces an urgent need to transition fromits traditional economic growth model,which is heavily reliant on resource consumption.This study investigates the decoupling dynamics among economic growth,energy consumption,and carbon emissions in the BTH region,along with the underlying driving forces,aiming to provide valuable insights for achieving the“dual carbon”targets and fostering high-quality regional development.First,the Tapio decoupling model is employed to analyze the decoupling relationships between economic growth,energy consumption,and carbon emissions in the BTH region from 2000 to 2021.Second,the Logarithmic Mean Divisia Index decomposition method is applied to identify the key driving factors of carbon emission reduction and quantify their respective contributions.Finally,targeted policy recommendations are proposed based on the empirical findings to support regional coordinated development.The results indicate that(1)all three sub-regions within the BTH region have demonstrated consistent improvements in energy utilization efficiency and a gradual decline in carbon emission intensity,although the degree of progress varies across regions;(2)differentiated decoupling states exist between carbon emissions and both economic growth and energy consumption,with Beijing showing significant decoupling,while Tianjin and Hebei Province experience a“rebound”phenomenon following a phase of decoupling;(3)energy consumption intensity and industrial structure optimization have notably positive effects on carbon emission reduction,whereas other factors contribute to varying degrees to the exacerbation of carbon emissions;(4)the impacts of driving factors on carbon emissions exhibit significant spatio-temporal disparities.Based on these findings,the study recommends enhancing fiscal incentives,optimizing industrial structures,improving energy efficiency,and establishing a coordinated regional governance framework to facilitate the BTH region’s low-carbon transition and sustainable development.展开更多
Quantifying material use in infrastructure development and analyzing its relationship with economic growth is essential for enhancing resource efficiency and steering regional resource management toward sustainable de...Quantifying material use in infrastructure development and analyzing its relationship with economic growth is essential for enhancing resource efficiency and steering regional resource management toward sustainable development.This study systematically assessed infrastructure related material use in 30 provinces,autonomous regions,and municipalities in China during 1978-2022.The result indicated that material stock has experienced significant growth,increasing from 16.91×10^(9)t in 1978 to 103.60×10^(9)t in 2022,with an average annual growth rate of 4.20%.However,from 1978 to 2015,material input followed a strong upward trend but saturated after 2015.At the national level,material input peaked in 2015,after which it began to decline.The central region reached its peak earlier in 2013,while the eastern and western regions peaked in 2015.Using a decoupling analysis framework,this study revealed that nationally,the elasticity value between material stock and gross domestic product(GDP)remained near or above 1.0,reflecting continued reliance on stock accumulation.Regionally,the elasticity value between material stock and GDP has increased in the central and western regions during 1978-2022,whereas elasticity value between material stock and GDP in the eastern region showed a slower growth rate but still struggled to achieve absolute decoupling.Moreover,the elasticity value between material input and GDP has declined at the national level,presenting a relative decoupling,with some regions already achieving absolute decoupling.The eastern region was closer to absolute decoupling,while the central and western regions,though still intensive in material input,exhibited faster declines in elasticity.Accelerating the transition from linear to circular economy is an essential step for China to achieve absolute decoupling and long-term sustainability.Finally,this research recommends promoting the adoption of renewable energy,driving industrial upgrading,implementing compact urban design,and extending the lifespan of infrastructure to reduce material dependency and achieve sustainable infrastructure transformation at the national level.展开更多
With the increasingly stringent national environmental protection policies,the ultra-low emission transformation of industrial coal-fired grate boilers and the highly efficient utilization of biomass resources or wast...With the increasingly stringent national environmental protection policies,the ultra-low emission transformation of industrial coal-fired grate boilers and the highly efficient utilization of biomass resources or wastes are becoming increasingly urgent in China.This study first proposes a novel and simple configuration for industrial grate boilers to integrate the decoupling combustion and flue gas recirculation or co-firing technologies,so as to reduce pollutant emission but improve thermal efficiency.Burning coal briquettes in the novel grate boiler,the original NO_(x) emissions can be remarkably decreased to as low as 56 mg· m^(-3),corresponding to the reduction efficiency of 82.8% in comparison with the average value in traditional coal-fired grate boilers.Co-firing coal briquettes with straw pellets in the novel grate boiler,the strongest synergistic effect of NO_(x) reduction is observed at the blending mass fraction of 50%,in which the NOxemissions can be further mitigated by at most 16.0% on top of the already reduced amount by decoupling combustion to reach less than about 165 mg· m^(-3).The novel grate boiler allows co-firing Chinese medicine residue with high water content at the blending mass fraction of up to 30% on the premise of low NO_(x) and CO emissions.All experimental results in this study demonstrated the obvious superiorities of the novel grate boiler in reducing NO_(x) and CO emissions and mitigating both slagging tendency and slag carbon content,which can be attributed to either the cumulative effects of decoupling combustion with flue gas recirculation or the synergistic effects of cofiring coal-biomass blends.The newly-developed travelling-grate decoupling combustion technology can be expected to provide an economical and convenient measure for the ultra-low NO_(x) emission transformation of industrial coal-fired grate boilers as well as the clean and highly efficient consumption of biomass wastes with high water content or difficulty to burn in China.展开更多
A control strategy of repetitive control without inductorance decoupling was proposed to address the problem of high total harmonic distortion(THD)rate of the network-side current caused by the reduced stability of th...A control strategy of repetitive control without inductorance decoupling was proposed to address the problem of high total harmonic distortion(THD)rate of the network-side current caused by the reduced stability of the rectifier module of the DC charging pile under weak grid as well as the dead zone and nonlinearity of switching devices during charging.Firstly,the parallel repetitive control was constructed in the inner current loop,and the proportional-integral(PI)+repetitive controller based on parallel structure was designed.For system compensation,a second-order low-pass filter was selected to correct the system,and the network-side current harmonics were actively suppressed without increasing the filtering device,which effectively improves the quality of grid-connected current.Secondly,based on the synthetic vector method,the controller parameters were designed to realize the elimination of main pole by establishing two synchronous rotation coordinate system vector differential equations,so as to realize the inductanceless decoupling to cope with the influence of network-side inductance fluctuation on the stability of the control system under weak grid.By theoretical analysis and simulation,the proposed control strategy was embedded into the self-developed digital signal processor for the rectifier module of DC charging pile,simulated dynamic and steady-state operation experiments were conducted,and comparative analysis was performed to prove the feasibility of the proposed control strategy.展开更多
The dual three-phase PMSM(DTP-PMSM)drives have received wide attention at high-power high-efficiency applications due to their merits of high output current ability and copper-loss-free field excitation.Meanwhile,the ...The dual three-phase PMSM(DTP-PMSM)drives have received wide attention at high-power high-efficiency applications due to their merits of high output current ability and copper-loss-free field excitation.Meanwhile,the DTPPMSM drive provides higher fault-tolerant capability for highreliability applications,e.g.,pumps and actuators in aircraft.For high-power drives with limited switching frequencies and highspeed drives with large fundamental frequencies,the ratio of switching frequency to fundamental frequency,i.e.,the carrier ratio,is usually below 15,which would significantly degrade the control performance.The purpose of this paper is to review the recent work on the modulation and control schemes for improving the operation performance of DTP-PMSM drives with low carrier ratios.Specifically,three categories of methods,i.e.,the space vector modulation based control,the model predictive control(MPC),and the optimized pulse pattern(OPP)based control are reviewed with principles and performance.In addition,brief discussions regarding the comparison and future trends are presented for low-carrier-ratio(LCR)modulation and control schemes of DTP-PMSM drives.展开更多
One kind of movable-pair analysis method is adopted to analyze the configuration of a 3-7R （revolute-pair） parallel decoupling mechanism, and the mechanism＇s characteristics are summarized. The mechanism has three ...One kind of movable-pair analysis method is adopted to analyze the configuration of a 3-7R （revolute-pair） parallel decoupling mechanism, and the mechanism＇s characteristics are summarized. The mechanism has three orthogonal distributional branch-chains, and all movable pairs are rotational joints. The movable platform of the mechanism has x, y, z translational decoupling directions. Furthermore, in order to verify the mechanism＇s decoupling characteristics, the mechanism＇s kinematics analysis is solved, and the mechanism＇s direct/inverse kinematics model, input/output velocities and accelerations are deduced, which confirm its decoupling movement characteristics. Finally, one kind of mechanism link decomposed-integrated approach is adopted, and the mechanism＇s dynamics model is completed with the Lagrange method, which also proves its decoupling force characteristics. All of these works provide significant theory for the further study of the mechanism＇s control strategy, design, path planning etc.展开更多
Unlike previous theories with velocity and/or elastic modulus averaging, we use a three-phase porous rock physics model developed by Santos for analyzing the seismic response of two immiscible fluids in saturated poro...Unlike previous theories with velocity and/or elastic modulus averaging, we use a three-phase porous rock physics model developed by Santos for analyzing the seismic response of two immiscible fluids in saturated porous media. Considering reservoir reference pressure and coupling drag of two fluids in pores, the effects of frequency, porosity, and gas saturation on the phase velocities of the P-and S-waves are discussed in detail under field conditions. The effects of porosity and gas saturation on Vp/Vs are also provided. The data for our numerical experiments are from a sample of deep volcanic rock from Daqing. The numerical results show that the frequency dispersion effect can be ignored for deep volcanic rocks with low porosity and low permeability. It is concluded that for deep volcanic rocks the effect of gas content in pores on Vp/Vs is negligible but the effect of porosity is significant when there is a certain amount of water contained in the pores. The accurate estimate of lithology and porosity in this case is relatively more important.展开更多
基金Project supported by the National Natural Science Foundation of China(Nos.12172149,12172151,and 12202378)the MOE Key Laboratory of Fututer Intelligent Manufacturing Technologies for High-End Equipment of China(No.FIMFYUST-2025B07)+1 种基金the Guangzhou Municipal Bureau of Science and Technology of China(No.SL2023A04J01461)the Ministry of Science and Technology of China(No.G20221990122)。
文摘This study focuses on a new and high-efficiency approach in a unified sense of accurately simulating strength-degrading effects for geomaterials,including non-symmetric hardening-to-softening effects in tension and compression as well as non-symmetric tensile and compressive stiffness-degrading effects during unloading.It is intended to bypass both modeling and numerical complexities involved in existing approaches.To this goal,new elastoplastic equations are established with new numerical techniques.With a decoupling technique of treating tension-compression asymmetry,the foregoing complex effects are automatically incorporated as inherent response features of the new elastoplastic equations,thus bypassing usual modeling complexities.A new numerical technique of renormalizing piecewise spline functions is introduced to resolve the central yet tough issue of obtaining accurate and unified expressions for the tensile and compressive strength functions,thus bypassing usual numerical complexities and uncertainties in treating numerous unknown parameters and multiple ad hoc criteria.As such,the new approach is not only of wide applicability for various geomaterials but also of high computational efficiency with no more than three adjustable parameters.Toward validating the efficacy of the new approach,numerical examples for granite,salt rock,and sandstone-concrete combined body as well as plain concrete,high-performance concrete,and ultrahigh-performance concrete are presented by comparing model predictions with multiple data sets for strength-degrading effects in tension and compression.
基金supported by the National Natural Science Foundation of China(Nos.52422408 and 52171031)the Liaoning Xingliao Talents-Top-notch Young Talents Project(No.XLYC2203064)+1 种基金the Excellent Youth Fund of Liaoning Natural Science Foundation(No.2023JH3/10200001)the Fundamental Research Funds for the Central Universities(No.N2425004).
文摘The transient phenomena of re-oxidation and slag entrapment occurring in the tundish during the ladle change-over process have been proven detrimental to clean steel production.Therefore,an unsteady three-phase turbulence model,coupling velocity,temperature,and phase field was established to study the effect of the ladle shroud immersion depth on the slag eye formation,slag entrainment,slag dragging,air dragging,and flow characteristics during the ladle change-over process of a two-strand tundish.The results showed that reducing the immersion depth decreases the high-velocity region area under the slag layer in the quasi-steady process.During the emptying stage,as the molten bath level gradually decreases,the outlet temperature exhibits a trend of initially decreasing and subsequently increasing across all three shroud immersion depths.However,under a 210 mm shroud immersion depth,molten slag and air are dragged into the shroud,forming slag droplets and causing significant fluctuations,with a maximum scalar velocity of 0.0764 m/s at the monitoring point.In the filling stage,air and molten slag are dragged into the molten bath,forming bubbles and slag droplets at an immersion depth of 210 mm.Bubbles are observed within the molten slag layer,which can readily cause an emulsification phenomenon,making it easier to be dragged as slag droplets.Additionally,the slag eye area measured under 210 mm immersion depth at 45 s is 0.303 m^(2),while the maximum scalar velocity of 2.4259 m/s is detected at 12 s.At an immersion depth of 360 mm,the average area of the slag eye is minimized to 0.06268 m2,with corresponding variances of 0.006753,representing the optimal immersion depth.
基金supported by the National Science Foundationof China(Nos.52305127 and 52475130)。
文摘Early fault detection for spiral bevel gears is crucial to ensure normal operation and prevent accidents.The harmonic components,excited by the time-varying mesh stiffness,always appear in measured vibration signal.How to extract the periodical impulses that indicate gear localized fault buried in the intensive noise and interfered by harmonics is a challenging task.In this paper,a novel Periodical Sparse-Assisted Decoupling(PSAD)method is proposed as an optimization problem to extract fault feature from noisy vibration signal.The PSAD method decouples the impulsive fault feature and harmonic components based on the sparse representation method.The sparsity within and across groups property and the periodicity of the fault feature are incorporated into the regularizer as the prior information.The nonconvex penalty is employed to highlight the sparsity of fault features.Meanwhile,the weight factor based on2norm of each group is constructed to strengthen the amplitude of fault feature.An iterative algorithm with Majorization-Minimization(MM)is derived to solve the optimization problem.Simulation study and experimental analysis confirm the performance of the proposed PSAD method in extracting and enhancing defect impulses from noisy signal.The suggested method surpasses other comparative methods in extracting and enhancing fault features.
基金Project(61174132) supported by the National Natural Science Foundation of ChinaProject(09JJ6098) supported by the Natural Science Foundation of Hunan Province, China
文摘Taking three-phase electrode adjusting system of submerged arc furnace as study object which has nonlinear, time-variant, multivariable and strong coupling features, a neural adaptive PSD(proportion, sum and differential) dispersive decoupling controller was developed by combining neural adaptive PSD algorithm with dispersive decoupling network. In this work, the production technology process and control difficulties of submerged arc furnace were simply introduced, the necessity of establishing a neural adaptive PSD dispersive decoupling controller was discussed, the design method and the implementation steps of the controller are expounded in detail, and the block diagram of the controlled system is presented. By comparison with experimental results of the conventional PID controller and the adaptive PSD controller, the decoupling ability, adaptive ability, self-learning ability and robustness of the neural adaptive PSD dispersive decoupling controller have been testified effectively. The controller is applicable to the three-phase electrode adjusting system of submerged arc furnace, and it will play an important role for achieving the power balance of three-phrase electrodes, saving energy and reducing consumption in the process of smelting.
基金support by Hong Kong RGC General Research Fund(16217824,16213825,16203923,and 16217824)National Natural Science Foundation of China(N_HKUST638/23)+1 种基金Research Grants Council Joint Research Scheme(62361166630)Guangdong Basic and Applied Basic Research Foundation(2023B1515130007).
文摘Human skin exhibits a remarkable capability to perceive contact forces and environmental temperatures,providing complex information that is essential for its subtle control.Despite recent advancements in soft tactile sensors,accurately decoupling signals—specifically separating forces from directional orientation and temperature—remains a challenge thus resulting in failure to meet the advanced application requirements of robots.This study proposes,F3T,a multilayer soft sensor unit designed to achieve isolated measurements and mathematical decoupling of normal pressure,omnidirectional tangential forces,and temperature.We developed a circular coaxial magnetic film featuring a floating mount multilayer capacitor that facilitated the physical decoupling of normal and tangential forces in all directions.Additionally,we incorporated an ion gel-based temperature-sensing film into the tactile sensor.The proposed sensor was resilient to external pressures and deformations,and could measure temperature and significantly eliminate capacitor errors induced by environmental temperature changes.In conclusion,our novel design allowed for the decoupled measurement of multiple signals,laying the foundation for advancements in high-level robotic motion control,autonomous decision-making,and task planning.
基金supported in part by the National Natural Science Foundation of China under Grant 62303333in part by the Project of Hetao Shenzhen-Hong Kong Science and Technology Innovation Cooperation Zone under Grant HZQB-KCZYB-2020083.
文摘To achieve high power rating and low current harmonics of motor drive,this paper develops a dual three-phase open-winding permanent magnet synchronous motor(DTP-OW-PMSM)drive with the DC-link voltage ratio of 2:1:1.Based on this topology,this paper proposes a DTP four-level space vector pulse width modulation(DTP-FL SVPWM)strategy.First,two identical three-phase four-level space vector diagrams are constructed and divided.Then,three adjacent vectors nearest to the reference vector in each diagram are selected for the vector synthesis to guarantee high modulation precision and low switching frequency.Furthermore,to avoid the modulation error caused by the voltage deviation,the proposed DTP-FL SVPWM strategy is further optimized through unified duty ratio compensation(UDRC).The effectiveness of the proposed strategy is verified through experiments.
文摘The elimination of the vertical tail in tailless aircraft results in a significant decrease in heading static stability,causing substantial coupling among the three control channels.In addition,in specific operational scenarios,the tailless aircraft is prone to electromagnetic interference,leading to the generation of high-frequency noise and consequently compromising their control performance.To address these issues,a decoupling control method based on a fractional-order error extended state observer(FOEESO)is proposed.A nonlinear model of a tailless aircraft with thrust vectoring capabilities is first developed.The decoupling control design for the three control channels is then implemented using FOEESO,with the asymptotic convergence conditions outlined.The proposed method is evaluated through simulations and compared to coupled control and linear extended state observer(LESO)techniques.Numerical simulations demonstrate that the FOEESO-based control methodology achieves effective decoupling,exhibiting 6.9%and 11.7%reductions in integral absolute error(IAE)relative to LESO under nominal operational conditions and critical fault scenarios,respectively.These improvements thereby highlight FOEESO’s capability to enhance closed-loop stability and tracking precision in tailless aircraft control systems.
基金supported in part by the Open Fund of State Key Laboratory of Precision Electronic Manufacturing Technology and Equipment,Guangdong University of Technology(Grant No.JMDZ2021007)in part by the Guangdong International Cooperation Program of Science and Technology(Grant No.2022A0505050078).
文摘Planar positioning systems are widely utilized in micro and nano applications.The challenges in modeling and control of XYΘflexure-based mechanisms include hysteresis of the piezoelectric actuators,couplings among the input axes,and coupled linear and angular motions of the end effector.This paper presents an inverse hysteresis-coupling hybrid model to account for such hysteresis and couplings.First,a specially designed kinematic chain is adopted to transfer the pose of the end effector into the linear motions at three prismatic joints.Second,an inverse hysteresis-coupling hybrid model is developed to linearize and decouple the system via a multilayer feedforward neural network.A fractional-order PID controller is also integrated to improve the motion accuracy of the overall system.Experimental results demonstrate that the proposed method can accurately control the motion of the end effector with improved accuracy and robustness.
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the National Natural Science Foundation of China[Grant No.52270183].
文摘Exploring the factors driving the decoupling of China’s sulfur dioxide(SO_(2))emissions from economic growth(DEI)is crucial for achieving sustainable development.By analyzing the decoupling indicators and driving factors at both the generation and treatment stages of SO_(2),more effective targeted mitigation strategies can be developed.We employ the Tapio decoupling model and propose a two-stage method to examine the decoupling issues related to SO_(2).Our findings indicate that:①DEI shows a steady and significant improvement,with SO_(2)emission intensity identified as the primary driver.②for the decoupling of economic growth and SO_(2)generation,energy scale serves as the largest stimulator,while the effect of energy intensity changes from negative to positive,and pollution intensity is first positive and then negative.③For the decoupling of SO_(2)generation and SO_(2)removal,treatment efficiency leads as the largest promoter,followed by treatment intensity.Based on these results,this study recommends that China focuses more on enhancing clean energy utilization and the effectiveness of treatment processes.
文摘The growing demand for efficient high-power switching power supplies has spurred interest in advanced topologies.The three-phase VIENNA converter stands out for its high power factor,simplified structure,and robust performance.Current research focuses on its operational principles,control strategies,and behavior under various load conditions.Key considerations include component selection,thermal management,and EMI/EMC optimization.This topology finds applications across renewable energy systems,industrial equipment,telecommunications,and electric vehicle charging infrastructures.Comparative analyses with alternative topologies and cost-benefit evaluations are also addressed.Future developments are expected to emphasize the integration of wide-bandgap devices and advancements in digital control techniques to further enhance efficiency and system performance.
基金Ningbo Scientific and Technological Innovation 2025 Major Project,Grant/Award Number:2020Z022German Research Foundation(DFG)grants,Grant/Award Numbers:MA 5144/13-1,MA 5144/28-1+6 种基金the National Natural Science Foundation of China,Grant/Award Numbers:62204246,51931011,51971233,52127803,62174165the External Cooperation Program of Chinese Academy of Sciences,Grant/Award Numbers:174433KYSB20190038,174433KYSB20200013the Instrument Developing Project of the Chinese Academy of Sciences,Grant/Award Number:YJKYYQ20200030K.C.Wong Education Foundation,Grant/Award Number:GJTD-2020-11Chinese Academy of Sciences Youth Innovation Promotion Association,Grant/Award Number:2018334Zhejiang Provincial Key R&D Program,Grant/Award Numbers:2021C01183,2022C01032the National Natural Science Foundation of Zhejiang Province of China,Grant/Award Number:LQ23F040004.
文摘The progress from intelligent interactions requires electronic skin(E-skin)to shift from single-functional perception to multisensory capabilities.However,the intuitive and interference-free reading of multiple sensory signals without involving complex algorithms is a critical challenge.Herein,we propose a flexible multisensory E-skin by developing a highly homogeneous dispersion of BaTiO_(3)nanoparticles in polydimethylsiloxane dielectric layer.The E-skin is sensitive to externally applied pressure as well as temperature and can distinguish dual synergetic stimuli by the time decoupling effect.The pressure and temperature perception was achieved in an individual device,which greatly reduced the structural complexity compared with multifunctional integrated devices.The sensitivity of E-skin for pressure detection is as high as 0.0724 kPa^(−1)and the detection range reaches as wide as 15.625-10 MPa.The sensitivity to temperature detection is as high as−1.34℃^(−1)and the detection range reaches 20-200℃.More importantly,by equipping with a multilayer neural network,the evolution from tactile perception to advanced intelligent tactile cognition is demonstrated.
基金funded by the Science and Technology Project of State Grid Corporation of China(No.52018F240002)the National Natural Science Foundation of China(72403087)the National Natural Science Foundation of China(72173043).
文摘Against the backdrop of regional coordinated development and China’s“dual carbon”strategic objectives,the Beijing-Tianjin-Hebei(BTH)region faces an urgent need to transition fromits traditional economic growth model,which is heavily reliant on resource consumption.This study investigates the decoupling dynamics among economic growth,energy consumption,and carbon emissions in the BTH region,along with the underlying driving forces,aiming to provide valuable insights for achieving the“dual carbon”targets and fostering high-quality regional development.First,the Tapio decoupling model is employed to analyze the decoupling relationships between economic growth,energy consumption,and carbon emissions in the BTH region from 2000 to 2021.Second,the Logarithmic Mean Divisia Index decomposition method is applied to identify the key driving factors of carbon emission reduction and quantify their respective contributions.Finally,targeted policy recommendations are proposed based on the empirical findings to support regional coordinated development.The results indicate that(1)all three sub-regions within the BTH region have demonstrated consistent improvements in energy utilization efficiency and a gradual decline in carbon emission intensity,although the degree of progress varies across regions;(2)differentiated decoupling states exist between carbon emissions and both economic growth and energy consumption,with Beijing showing significant decoupling,while Tianjin and Hebei Province experience a“rebound”phenomenon following a phase of decoupling;(3)energy consumption intensity and industrial structure optimization have notably positive effects on carbon emission reduction,whereas other factors contribute to varying degrees to the exacerbation of carbon emissions;(4)the impacts of driving factors on carbon emissions exhibit significant spatio-temporal disparities.Based on these findings,the study recommends enhancing fiscal incentives,optimizing industrial structures,improving energy efficiency,and establishing a coordinated regional governance framework to facilitate the BTH region’s low-carbon transition and sustainable development.
基金supported by the Shanghai Committee of Science and Technology Fund(22ZR1419300)the Academic Year 2025 Ritsumeikan Asia Pacific University Academic Research Subsidy(Grants-in-Aid Reapplication Type).
文摘Quantifying material use in infrastructure development and analyzing its relationship with economic growth is essential for enhancing resource efficiency and steering regional resource management toward sustainable development.This study systematically assessed infrastructure related material use in 30 provinces,autonomous regions,and municipalities in China during 1978-2022.The result indicated that material stock has experienced significant growth,increasing from 16.91×10^(9)t in 1978 to 103.60×10^(9)t in 2022,with an average annual growth rate of 4.20%.However,from 1978 to 2015,material input followed a strong upward trend but saturated after 2015.At the national level,material input peaked in 2015,after which it began to decline.The central region reached its peak earlier in 2013,while the eastern and western regions peaked in 2015.Using a decoupling analysis framework,this study revealed that nationally,the elasticity value between material stock and gross domestic product(GDP)remained near or above 1.0,reflecting continued reliance on stock accumulation.Regionally,the elasticity value between material stock and GDP has increased in the central and western regions during 1978-2022,whereas elasticity value between material stock and GDP in the eastern region showed a slower growth rate but still struggled to achieve absolute decoupling.Moreover,the elasticity value between material input and GDP has declined at the national level,presenting a relative decoupling,with some regions already achieving absolute decoupling.The eastern region was closer to absolute decoupling,while the central and western regions,though still intensive in material input,exhibited faster declines in elasticity.Accelerating the transition from linear to circular economy is an essential step for China to achieve absolute decoupling and long-term sustainability.Finally,this research recommends promoting the adoption of renewable energy,driving industrial upgrading,implementing compact urban design,and extending the lifespan of infrastructure to reduce material dependency and achieve sustainable infrastructure transformation at the national level.
基金supported by the Strategic Priority Research Programs of Chinese Academy of Sciences (XDA29020401)the Fund of State Key Laboratory of Mesoscience and Engineering (Meso-23-A02)。
文摘With the increasingly stringent national environmental protection policies,the ultra-low emission transformation of industrial coal-fired grate boilers and the highly efficient utilization of biomass resources or wastes are becoming increasingly urgent in China.This study first proposes a novel and simple configuration for industrial grate boilers to integrate the decoupling combustion and flue gas recirculation or co-firing technologies,so as to reduce pollutant emission but improve thermal efficiency.Burning coal briquettes in the novel grate boiler,the original NO_(x) emissions can be remarkably decreased to as low as 56 mg· m^(-3),corresponding to the reduction efficiency of 82.8% in comparison with the average value in traditional coal-fired grate boilers.Co-firing coal briquettes with straw pellets in the novel grate boiler,the strongest synergistic effect of NO_(x) reduction is observed at the blending mass fraction of 50%,in which the NOxemissions can be further mitigated by at most 16.0% on top of the already reduced amount by decoupling combustion to reach less than about 165 mg· m^(-3).The novel grate boiler allows co-firing Chinese medicine residue with high water content at the blending mass fraction of up to 30% on the premise of low NO_(x) and CO emissions.All experimental results in this study demonstrated the obvious superiorities of the novel grate boiler in reducing NO_(x) and CO emissions and mitigating both slagging tendency and slag carbon content,which can be attributed to either the cumulative effects of decoupling combustion with flue gas recirculation or the synergistic effects of cofiring coal-biomass blends.The newly-developed travelling-grate decoupling combustion technology can be expected to provide an economical and convenient measure for the ultra-low NO_(x) emission transformation of industrial coal-fired grate boilers as well as the clean and highly efficient consumption of biomass wastes with high water content or difficulty to burn in China.
基金supported by National Natural Science Foundation of China(No.61903291)Shaanxi Province Key R&D Program(No.2022GY-134)。
文摘A control strategy of repetitive control without inductorance decoupling was proposed to address the problem of high total harmonic distortion(THD)rate of the network-side current caused by the reduced stability of the rectifier module of the DC charging pile under weak grid as well as the dead zone and nonlinearity of switching devices during charging.Firstly,the parallel repetitive control was constructed in the inner current loop,and the proportional-integral(PI)+repetitive controller based on parallel structure was designed.For system compensation,a second-order low-pass filter was selected to correct the system,and the network-side current harmonics were actively suppressed without increasing the filtering device,which effectively improves the quality of grid-connected current.Secondly,based on the synthetic vector method,the controller parameters were designed to realize the elimination of main pole by establishing two synchronous rotation coordinate system vector differential equations,so as to realize the inductanceless decoupling to cope with the influence of network-side inductance fluctuation on the stability of the control system under weak grid.By theoretical analysis and simulation,the proposed control strategy was embedded into the self-developed digital signal processor for the rectifier module of DC charging pile,simulated dynamic and steady-state operation experiments were conducted,and comparative analysis was performed to prove the feasibility of the proposed control strategy.
基金supported by the National Key Research and Development Program of China under the grant of 2022YFB3403100。
文摘The dual three-phase PMSM(DTP-PMSM)drives have received wide attention at high-power high-efficiency applications due to their merits of high output current ability and copper-loss-free field excitation.Meanwhile,the DTPPMSM drive provides higher fault-tolerant capability for highreliability applications,e.g.,pumps and actuators in aircraft.For high-power drives with limited switching frequencies and highspeed drives with large fundamental frequencies,the ratio of switching frequency to fundamental frequency,i.e.,the carrier ratio,is usually below 15,which would significantly degrade the control performance.The purpose of this paper is to review the recent work on the modulation and control schemes for improving the operation performance of DTP-PMSM drives with low carrier ratios.Specifically,three categories of methods,i.e.,the space vector modulation based control,the model predictive control(MPC),and the optimized pulse pattern(OPP)based control are reviewed with principles and performance.In addition,brief discussions regarding the comparison and future trends are presented for low-carrier-ratio(LCR)modulation and control schemes of DTP-PMSM drives.
基金The National High Technology Research and Development Program of China(863Program)(No.2006AA040202)
文摘One kind of movable-pair analysis method is adopted to analyze the configuration of a 3-7R （revolute-pair） parallel decoupling mechanism, and the mechanism＇s characteristics are summarized. The mechanism has three orthogonal distributional branch-chains, and all movable pairs are rotational joints. The movable platform of the mechanism has x, y, z translational decoupling directions. Furthermore, in order to verify the mechanism＇s decoupling characteristics, the mechanism＇s kinematics analysis is solved, and the mechanism＇s direct/inverse kinematics model, input/output velocities and accelerations are deduced, which confirm its decoupling movement characteristics. Finally, one kind of mechanism link decomposed-integrated approach is adopted, and the mechanism＇s dynamics model is completed with the Lagrange method, which also proves its decoupling force characteristics. All of these works provide significant theory for the further study of the mechanism＇s control strategy, design, path planning etc.
文摘Unlike previous theories with velocity and/or elastic modulus averaging, we use a three-phase porous rock physics model developed by Santos for analyzing the seismic response of two immiscible fluids in saturated porous media. Considering reservoir reference pressure and coupling drag of two fluids in pores, the effects of frequency, porosity, and gas saturation on the phase velocities of the P-and S-waves are discussed in detail under field conditions. The effects of porosity and gas saturation on Vp/Vs are also provided. The data for our numerical experiments are from a sample of deep volcanic rock from Daqing. The numerical results show that the frequency dispersion effect can be ignored for deep volcanic rocks with low porosity and low permeability. It is concluded that for deep volcanic rocks the effect of gas content in pores on Vp/Vs is negligible but the effect of porosity is significant when there is a certain amount of water contained in the pores. The accurate estimate of lithology and porosity in this case is relatively more important.
