The new energy power generation is becoming increasingly important in the power system.Such as photovoltaic power generation has become a research hotspot,however,due to the characteristics of light radiation changes,...The new energy power generation is becoming increasingly important in the power system.Such as photovoltaic power generation has become a research hotspot,however,due to the characteristics of light radiation changes,photovoltaic power generation is unstable and random,resulting in a low utilization rate and directly affecting the stability of the power grid.To solve this problem,this paper proposes a coordinated control strategy for a newenergy power generation system with a hybrid energy storage unit based on the lithium iron phosphate-supercapacitor hybrid energy storage unit.Firstly,the variational mode decomposition algorithm is used to separate the high and low frequencies of the power signal,which is conducive to the rapid and accurate suppression of the power fluctuation of the energy storage system.Secondly,the fuzzy control algorithm is introduced to balance the power between energy storage.In this paper,the actual data is used for simulation,and the simulation results show that the strategy realizes the effective suppression of the bus voltage fluctuation and the accurate control of the internal state of the energy storage unit,effectively avoiding problems such as overshoot and over-discharge,and can significantly improve the stability of the photovoltaic power generation systemand the stability of the Direct Current bus.It is of great significance to promote the development of collaborative control technology for photovoltaic hybrid energy storage units.展开更多
The press-fit connector is a typical plug-and-play solderless connection,and it is widely used in signal transmission in fields such as communication and automotive devices.This paper focuses on inverse designing and ...The press-fit connector is a typical plug-and-play solderless connection,and it is widely used in signal transmission in fields such as communication and automotive devices.This paper focuses on inverse designing and optimization of geometric structure,as well as insertion-withdrawal forces of press-fit connector using artificial neural network(ANN)-assisted optimization method.The ANN model is established to approximate the relationship between geometric parameters and insertion-withdrawal forces,of which hyper-parameters of neural network are optimized to improve model performance.Two numerical methods are proposed for inverse designing structural parameters(Model-I)and multi-objective optimization of insertion-withdrawal forces(Model-II)of press-fit connector.In Model-I,a method for inverse designing structure parameters is established,of which an ANN model is coupled with single-objective optimization algorithm.The objective function is established,the inverse problem is solved,and effectiveness is verified.In Model-II,a multi-objective optimization method is proposed,of which an ANN model is coupled with genetic algorithm.The Pareto solution sets of insertion-withdrawal forces are obtained,and results are analyzed.The established ANN-coupled numerical optimization methods are beneficial for improving the design efficiency,and enhancing the connection reliability of the press-fit connector.展开更多
As space equipment become larger in size and more flexible,generalized mechanisms are being widely used in space-deployable structures.Dynamic modeling of large-scale generalized space-deployable mechanisms is challen...As space equipment become larger in size and more flexible,generalized mechanisms are being widely used in space-deployable structures.Dynamic modeling of large-scale generalized space-deployable mechanisms is challenging owing to the coupling between the deformation of flexible links and rigid body motion.This study develops a dynamic modeling method for generalized mechanisms using the local frame of the SE(3)Lie group.The model represents both rigid and flexible links within a unified Lie group setting.The expressions for the velocities of rigid links and deformation of flexible links are derived using the Lie algebra framework.The nonuniqueness of the degrees of freedom of generalized kinematic pairs is considered,and the velocity fields of kinematic pairs in different situations are expressed.The equations of motion are derived using Hamilton’s principle.Because the velocities are expressed in the local frame,the mass matrix in the equation is constant,which yields a compact and unified expression for the dynamic equation.A Lie group generalized-αtime integration method is adopted to ensure numerical stability and efficiency in simulating multibody systems with large rotations and deformations.Two numerical examples are studied to demonstrate a formulation that reflects the motion responses under varying configurations and loading conditions.This study broadens the application of the local frame of the Lie group formulation in space mechanisms and provides a new concept for dynamic modeling of generalized mechanisms.展开更多
Robots are key to expanding the scope of space applications.The end-to-end training for robot vision-based detection and precision operations is challenging owing to constraints such as extreme environments and high c...Robots are key to expanding the scope of space applications.The end-to-end training for robot vision-based detection and precision operations is challenging owing to constraints such as extreme environments and high computational overhead.This study proposes a lightweight integrated framework for grasp detection and imitation learning,named GD-IL;it comprises a grasp detection algorithm based on manipulability and Gaussian mixture model(manipulability-GMM),and a grasp trajectory generation algorithm based on a two-stage robot imitation learning algorithm(TS-RIL).In the manipulability-GMM algorithm,we apply GMM clustering and ellipse regression to the object point cloud,propose two judgment criteria to generate multiple candidate grasp bounding boxes for the robot,and use manipulability as a metric for selecting the optimal grasp bounding box.The stages of the TS-RIL algorithm are grasp trajectory learning and robot pose optimization.In the first stage,the robot grasp trajectory is characterized using a second-order dynamic movement primitive model and Gaussian mixture regression(GMM).By adjusting the function form of the forcing term,the robot closely approximates the target-grasping trajectory.In the second stage,a robot pose optimization model is built based on the derived pose error formula and manipulability metric.This model allows the robot to adjust its configuration in real time while grasping,thereby effectively avoiding singularities.Finally,an algorithm verification platform is developed based on a Robot Operating System and a series of comparative experiments are conducted in real-world scenarios.The experimental results demonstrate that GD-IL significantly improves the effectiveness and robustness of grasp detection and trajectory imitation learning,outperforming existing state-of-the-art methods in execution efficiency,manipulability,and success rate.展开更多
The combination of advanced photoelectric detectors has rendered single-band camouflage materials ineffective,necessitating the development of infrared multispectral camouflage.However,the design and fabrication of ex...The combination of advanced photoelectric detectors has rendered single-band camouflage materials ineffective,necessitating the development of infrared multispectral camouflage.However,the design and fabrication of existing works remain complex as they usually require the integration of multiscale structures.Here,we introduce phase modulation into the infrared camouflage metasurfaces with metal-dielectric-metal configuration,enabling them to achieve camouflage across more bands.Based on this strategy,a simple but effective single-layer cascaded metasurface is demonstrated for the first time to achieve low reflection at multi-wavelength lasers,low infrared radiation in atmospheric windows,and broadband thermal management.As a proof-of-concept,a 4-inch sample with a minimum linewidth of 1.8μm is fabricated using photolithography.The excellent infrared multispectral camouflage performance is verified in experiments,showing low reflectance in 0.9–1.6μm,low infrared emissivity in mid-wavelength infrared(MWIR)and long-wavelength infrared(LWIR)bands,and high absorptance at the wavelength of 10.6μm.Meanwhile,broadband high emissivity in 5–8μm can provide high-performance radiative heat dissipation.When the input power is 1.57 W·cm^(-2),the surface/radiation temperature of the metasurface decreases by 5.3℃/18.7℃ compared to the reference.The proposed metasurface may trigger further innovation in the design and application of compact multispectral optical devices.展开更多
Photocatalysis is an important process in energy conversion and environmental usage because of its feasible,profitable,and environmentally safe benefits.Coordination chemistry of the CeO_(2)is gaining significant inte...Photocatalysis is an important process in energy conversion and environmental usage because of its feasible,profitable,and environmentally safe benefits.Coordination chemistry of the CeO_(2)is gaining significant interest because its nanocomposites show unique characteristics namely optically active,wide bandgap(Eg),reversible valence states(Ce^(3+/4+)),rich defect architectures,high O_(2)storage capability,ionic conductivity,and exceptional chemical resistance.Systematically summarized the importance of synthesis methods,particle morphology,and crystal structure aiming at how to heighten the efficacy of CeO_(2)-derived hybrid heterojunction(HHJ)photocatalyst.Selection of an appropriate synthesis method and morphology of the composite materials are beneficial in inhibiting the rapid electron-hole(e^(−)-h^(+))recombination,improvement in visible light adsorption,and large generation of e^(−)-h^(+)pairs to accelerate the photocatalysts activities.Various modification approaches include elemental doping(metal/non-metal doping),heterojunction construction(lower/wide Eg semiconductors(SCD),carbon,conducting polymeric materials),imperfection engineering,and multicomponent hybrid composites.These methods assist as a valuable resource for the rational design of effective CeO_(2)-based composite photocatalysts for sustainable development owing to the enhancement of oxygen species mobility,rapid charge transfer,maximum visible light captivation and slow down the charge recombination rate with increase photogeneration of e−-h+pairs.Also examines the advancements made in CeO_(2)conjugated hybrid composites in photo-oxidation of wastewater effluents(antibiotic/organic dyes/chemical/pharmaceutical),heavy metal removal,H2 production,CO_(2)reduction,and H2O splitting applications.Subsequently,the difficulties and fundamental ideas behind several heterojunction photocatalysts encountered by CeO_(2)-based composites are examined,and future directions for their development are suggested.展开更多
Silicon Carbide (SiC) wafers have been widely used in micro- and nano-devices due to their excellent optical and material properties. However, polishing SiC wafers has been challenging and inefficient, tending to caus...Silicon Carbide (SiC) wafers have been widely used in micro- and nano-devices due to their excellent optical and material properties. However, polishing SiC wafers has been challenging and inefficient, tending to cause significant surface crack and subsurface damage. This work proposed modifying SiC surface properties by ion implantation to improve machining efficiency, suppress surface crack, and reduce damage. High-energy ion implantation disrupted the SiC crystal lattice, reducing hardness and elastic modulus while increasing brittle-ductile transition depth, thus changing the removal mode from brittle fracture to plastic removal. Theoretical models of material removal rate and surface roughness were established for abrasive polishing of the SiC wafers. Polishing experiments were conducted on ion-implanted, modified SiC samples. The improvement mechanisms of ion implantation on surface damage, removal rate, morphology, and residual stress were investigated. The effect of ion implantation on the polished surface quality of SiC was investigated through orthogonal experiments. The results showed that ion implantation can significantly improve the average material removal rate of the SiC samples. Additionally, the ion-implanted samples had exhibited remarkable reductions in surface roughness, surface damage, and tensile residual stress.展开更多
Active adjustment technology is used to solve the problem of reduced electrical performance of large reflector antennas caused by environmental factors.This technology is crucial for the operation of antennas under hi...Active adjustment technology is used to solve the problem of reduced electrical performance of large reflector antennas caused by environmental factors.This technology is crucial for the operation of antennas under high-frequency working conditions.This paper proposes a full-path active adjustment strategy for dual-reflector antennas.This strategy takes into account the working mode of the adjustment mechanism under comprehensive influencing factors and achieves the optimal receiving performance at the full elevation by changing different adjustment algorithms.First,the relationship between the displacement of reflector and the wavefront phase was established based on geometric optics.Second,three adjustment algorithms of the double reflector antenna were compared and analyzed:based on the standard,the fit and the optimal parabolic surface,the calculation process of the adjustment amount was derived.An adjustment strategy model for multiple working conditions was proposed by introducing the elevation and the complexity coefficient and combining three adjustment algorithms.Finally,a finite element analysis was conducted on the dual-reflector antenna with a diameter of 110 m,and the advantages and disadvantages of different adjustment algorithms were compared.The results show that strategy model not only achieves the optimal state of the antenna at the full elevation,but also shortens the adjustment amount of the adjustment mechanism and improves the working efficiency of the antenna under various working conditions.展开更多
Acoustofluidics is a term describing the class of phenomena in which mechanical or acoustic vibrations induce a deformation or a flow in a fluid.Many deficiencies in our understanding of these phenomena remain to be a...Acoustofluidics is a term describing the class of phenomena in which mechanical or acoustic vibrations induce a deformation or a flow in a fluid.Many deficiencies in our understanding of these phenomena remain to be addressed,with respect to the fundamental theoretical framework as well as in numerous applications.In this regard,the frequency of external forcing is a key parameter.Owing to the low cost,substantial magnitude,and versatility associated with acoustofluidic phenomena at audible frequencies,studies of these phenomena in the audible range have emerged with increasing amount in recent years and have attracted considerable attention.However,compared with studies focusing on the ultrasonic frequency domain,critical features and information specific to audible acoustofluidics remain dispersed across many independent publications,and a systematic integration of the literature on this topic is necessary.Accordingly,this review summarizes the basic theory and methods for generating vibrations in the audible range,presents various applications thereof in biology,chemistry,and other fields,and provides a high-level overview of the current status of the topic to motivate developing interesting proposals for further research in this field of study.展开更多
Four-wheel independently driven electric vehicles(FWID-EV)endow a flexible and scalable control framework to improve vehicle performance.This paper integrates the torque vectoring and active suspension system(ASS)to e...Four-wheel independently driven electric vehicles(FWID-EV)endow a flexible and scalable control framework to improve vehicle performance.This paper integrates the torque vectoring and active suspension system(ASS)to enhance the vehicle’s longitudinal and vertical motion control performance.While the nonlinear characteristic of the tire model leads to a relatively heavier computational burden.To facilitate the controller design and ease the load,a half-vehicle dynamics system is built and simplified to the linear-time-varying(LTV)model.Then a model predictive controller is developed by formulating the objective function by comprehensively considering the safety,energy-saving and comfort requirements.The in-wheel motor efficiency and the power loss of tire slip are treated as optimization indices in this work to reduce energy consumption.Finally,the effectiveness of the proposed controller is verified through the rapid-control-prototype(RCP)test.The results demonstrate the enhancement of the energy-saving as well as comfort on the basis of vehicle stability.展开更多
In this paper,a multi-bus distributed Power Conditioning Unit(PCU)is proposed for the Space Solar Power Station with large scale photovoltaic(PV)array and power levels reaching MW level.In this unit,there are multiple...In this paper,a multi-bus distributed Power Conditioning Unit(PCU)is proposed for the Space Solar Power Station with large scale photovoltaic(PV)array and power levels reaching MW level.In this unit,there are multiple independent PV arrays.In each PV array,there are multiple independent PV subarrays.In this paper,a V-P droop control method with adaptive droop coefficient is proposed,which modifies the droop intercept based on the bus voltage deviation and the power per unit value of the PV array.This method ensures the accuracy of bus voltage and achieves proportional distribution of power between PV arrays based on the proposed topology structure in this paper.When the load changes or the output power of the PV array fluctuates,this method can ensure that power is distributed proportionally.The principle and control method of the proposed droop control method is analyzed in this paper.The effectiveness of the method is verified through MATLAB/Simulink simulation and experiment.Simulation and experimental results show that the proposed method can achieve power distributed proportionally when load changes and PV output power fluctuates,reduce bus voltage error caused by line impedance and differences in rated power of different PV arrays,and improve the performance of PV power generation system applied to space.展开更多
This paper studies the equilibrium state and trajectory dynamics of an axially symmetric Electric solar wind sail(E-sail)at arbitrary sail angles.The E-sail is assumed operating in a heliocentric-ecliptic orbit at app...This paper studies the equilibrium state and trajectory dynamics of an axially symmetric Electric solar wind sail(E-sail)at arbitrary sail angles.The E-sail is assumed operating in a heliocentric-ecliptic orbit at approximately one astronomic unit(au)from the Sun,and experiencing various dynamic disturbances like solar wind pressure,tether tension oscillations,and centrifugal forces.The study derives analytical expressions for the E-sail's equilibrium state and its maximal coning angle under small coning angle assumption.Subsequently,an improved propulsion model is developed for the E-sail in this equilibrium state.To assess the precision of these formulations,a high-fidelity E-sail dynamic model is constructed using the nodal position finite element method,where the tethers are modeled as two-noded tensile elements and the central spacecraft and remote units are simplified as lumped masses.Through thorough parametric analyses,this paper conclusively demonstrates that the operation of the E-sail at the equilibrium state can be achieved in accordance with the derived analytical prediction of the equilibrium state.Furthermore,the improved propulsion model is employed in trajectory analyses for a mission to reach the solar system's boundary.The study provides valuable insights and findings and foundation for the practical application and further advancement of the E-sail technology.展开更多
This paper presents analytical solutions for full-field radiation in magnetoelectric(ME)antennas,considering a fully magnetoelastic coupled constitutive relation.A nonlinear converse ME coupling model is established,i...This paper presents analytical solutions for full-field radiation in magnetoelectric(ME)antennas,considering a fully magnetoelastic coupled constitutive relation.A nonlinear converse ME coupling model is established,incorporating mechanical,electric,and magnetic variables with generalized Maxwell equations.This model emphasizes the essence of ME antennas,where radiation is achieved through strain/stress-mediated coupling between different phases.The magnetic flux density and electric displacement obtained from the model are used as sources to solve the full-field radiations of ME antennas.The proposed model is validated through existing experiments and simulations,demonstrating that the radiation performance of ME antennas is strongly influenced by nonlinear magneto-elastic coupling.The material parameters and magnetic bias significantly impact the magnetic flux density and far-field radiation due to the nonlinear magnetization process.The study reveals the mechanisms behind enhanced working bandwidth and frequency tuning by examining the frequency response of the radiation impedance with material parameters.By adjusting the initial magnetization rate,saturation magnetostriction,and saturation magnetization,the radiation efficiency/gain can be increased by 340%,108%,and 112%respectively.This model enhances our understanding of the full-field radiation of ME antennas and provides a foundation for designing tunable ME antennas.展开更多
Active reflectors are often used to compensate the surface distortion caused by environmental factors that degrade the electromagnetic performance of large high-frequency reflector antennas.This is crucial for maintai...Active reflectors are often used to compensate the surface distortion caused by environmental factors that degrade the electromagnetic performance of large high-frequency reflector antennas.This is crucial for maintaining high gain operation in antennas.A distortion compensation method for the active reflector of a large dual-reflector antenna is proposed.A relationship is established between the surface deformation and the optical path difference for the primary reflector by geometric optics.Subsequently,employing finite element analysis,a polynomial fitting approach is used to describe the impact of adjusting points on the reflector surface based on the coordinates of each node.By standardizing the positions of various panels on the reflector,the fitting ns can be applied to the reflector panels of similar shapes.Then,based on the distribution characteristics of the primary reflector panels,the adjustment equation for the actuators is derived by the influence matrix method.It can be used to determine the adjustment amount of actuators to reduce the rms of the optical path difference.And,the least squares method is employed to resolve the matrix equation.The example of a 110 m aperture dual-reflector antenna is carried out by finite element analysis and the proposed method.The results show that the optical path difference is reduced significantly at various elevation cases,which indicates that the proposed method is effective.展开更多
Real-time physiological information monitoring can predict and prevent disease, or improve treatment by early diagnosis. A comprehensive and continuous monitoring of human health requires highly integrated wearable an...Real-time physiological information monitoring can predict and prevent disease, or improve treatment by early diagnosis. A comprehensive and continuous monitoring of human health requires highly integrated wearable and comfortable sensing devices. To address this need, we propose a low-cost electronic fabric-enabled multifunctional flexible sensing integration platform that includes a flexible pressure sensor for monitoring postural pressure, a humidity sensor for monitoring the humidity of the skin surface, and a flexible temperature sensor for visualizing the ambient temperature around the human body. Thanks to the unique rough surface texture, hierarchical structure, and robust electromechanical features of the MXene-modified nonwoven fabrics, the flexible pressure sensor can achieve a monitoring sensitivity of 1529.1 kPa~(-1) and a pressure range of 150 kPa, which meets the demand for human pressure detection. In addition, the unique porous structure of the fabric and the stacked multilayer structure of MXene enable the humidity sensor to exhibit extremely high monitoring sensitivity, even through clothing, and still be able to detect the humidity on the skin surface.Temperature sensors based on screen-printed thermochromic liquid crystals enable visual monitoring in the range of 0℃–65℃. Through further integration with flexible printed circuit board circuits, we demonstrate a proof-of-concept device that enables real-time monitoring of human physiological information such as physical pressure, humidity, and ambient temperature environment, suggesting that the device provides an excellent platform for the development of commercially viable wearable healthcare monitors.展开更多
The objective is to design a variable structure proportional navigation law for the passive homingmissile so that the missile can hit the target with a minimum miss-distance and desired impact attitude anglewithin the...The objective is to design a variable structure proportional navigation law for the passive homingmissile so that the missile can hit the target with a minimum miss-distance and desired impact attitude anglewithin the required overlcad when it flies at a lower trajectory.This paper utilized the variable structure propor-tional navigation with terminal impact attitude angular constraint,and made estimation about the distance rateand distance between the missile and target,which broke the limitation of a passive homing seeker.Furthermore,the paper let the switch gain vary adaptively with time to avoid any larger initial overload.The mathematicalsimulation was completed by some studied passive homing missile's dynamic model,and the simulation resultsshowed that the navigation law of the passive homing missile can make the missile get the required miss-distance and desired impact attitude angle against tanks at lower trajectories and within the maximum overload;also this guidance law is much robust to the estimation eror of distance and distance rate.展开更多
A new meta-heuristic method is proposed to enhance current meta-heuristic methods for global optimization and test scheduling for three-dimensional （3D） stacked system-on-chip （SoC） by hybridizing grey wolf optimi...A new meta-heuristic method is proposed to enhance current meta-heuristic methods for global optimization and test scheduling for three-dimensional （3D） stacked system-on-chip （SoC） by hybridizing grey wolf optimization with differential evo- lution （HGWO）. Because basic grey wolf optimization （GWO） is easy to fall into stagnation when it carries out the operation of at- tacking prey, and differential evolution （DE） is integrated into GWO to update the previous best position of grey wolf Alpha, Beta and Delta, in order to force GWO to jump out of the stagnation with DE＇s strong searching ability. The proposed algorithm can accele- rate the convergence speed of GWO and improve its performance. Twenty-three well-known benchmark functions and an NP hard problem of test scheduling for 3D SoC are employed to verify the performance of the proposed algorithm. Experimental results show the superior performance of the proposed algorithm for exploiting the optimum and it has advantages in terms of exploration.展开更多
Many surveys on vehicle traffic safety have shown that the tire road friction coefficient(TRFC)is correlated with the probability of an accident.The probability of road accidents increases sharply on slippery road sur...Many surveys on vehicle traffic safety have shown that the tire road friction coefficient(TRFC)is correlated with the probability of an accident.The probability of road accidents increases sharply on slippery road surfaces.Therefore,accurate knowledge of TRFC contributes to the optimization of driver maneuvers for further improving the safety of intelligent vehicles.A large number of researchers have employed different tools and proposed different algorithms to obtain TRFC.This work investigates these different methods that have been widely utilized to estimate TRFC.These methods are divided into three main categories:off-board sensors-based,vehicle dynamics-based,and data-driven-based methods.This review provides a comparative analysis of these methods and describes their strengths and weaknesses.Moreover,some future research directions regarding TRFC estimation are presented.展开更多
Shearer and hydraulic support are matching equipments. To increase the operating speed of the shearer, the following speed of hydraulic support must be increased. This means increasing the volume of flow from emulsion...Shearer and hydraulic support are matching equipments. To increase the operating speed of the shearer, the following speed of hydraulic support must be increased. This means increasing the volume of flow from emulsion power station. Analyzing the operating characteristics of hydraulic supports, the number of simultaneously operating supports is obtained by means of pressure parameter and time history at a certain time, which is a theory base for development of control system to multi-pump emulsion power station.展开更多
New lead-free ferroelectric(0.94-x)BioNaTiO-0.06 BaTiOSrTiNbO(BNBT-STN,x = 0 and 0.2)are synthesized by using a solid state reaction process. In this work, an obvious evolution of dielectric relaxation behavior and sl...New lead-free ferroelectric(0.94-x)BioNaTiO-0.06 BaTiOSrTiNbO(BNBT-STN,x = 0 and 0.2)are synthesized by using a solid state reaction process. In this work, an obvious evolution of dielectric relaxation behavior and slim P-E hysteresis loops with high Pmax and low Pr is observed for BNBT-0.2 STN,indicating the dominant of ergodic relaxor phase with dynamic polar nano-regions(PNRs). A relatively large recoverable energy density(Wrec = 1.17 J/cm~3) with high energy efficiency(η= 91%) is obtained. Furthermore, it shows small variation(9%) in the temperature range of 30-150 ℃ and fatigue-free behavior,which can be attributed to the absence of ferroelectric domain in the relaxor phase. The achievement of these characteristics provides that tailoring by B-site vacancies is a potential route when designing a new energy-storage system for BNT-based relaxor ferroelectric materials.展开更多
基金supported by the State Grid Corporation of China Science and Technology Project,grant number 52270723000900K.
文摘The new energy power generation is becoming increasingly important in the power system.Such as photovoltaic power generation has become a research hotspot,however,due to the characteristics of light radiation changes,photovoltaic power generation is unstable and random,resulting in a low utilization rate and directly affecting the stability of the power grid.To solve this problem,this paper proposes a coordinated control strategy for a newenergy power generation system with a hybrid energy storage unit based on the lithium iron phosphate-supercapacitor hybrid energy storage unit.Firstly,the variational mode decomposition algorithm is used to separate the high and low frequencies of the power signal,which is conducive to the rapid and accurate suppression of the power fluctuation of the energy storage system.Secondly,the fuzzy control algorithm is introduced to balance the power between energy storage.In this paper,the actual data is used for simulation,and the simulation results show that the strategy realizes the effective suppression of the bus voltage fluctuation and the accurate control of the internal state of the energy storage unit,effectively avoiding problems such as overshoot and over-discharge,and can significantly improve the stability of the photovoltaic power generation systemand the stability of the Direct Current bus.It is of great significance to promote the development of collaborative control technology for photovoltaic hybrid energy storage units.
基金supported by the National Natural Science Foundation of China(No.52005378)the opening project fund of Materials Service Safety Assessment Facilities(No.MSAF-2021-107).
文摘The press-fit connector is a typical plug-and-play solderless connection,and it is widely used in signal transmission in fields such as communication and automotive devices.This paper focuses on inverse designing and optimization of geometric structure,as well as insertion-withdrawal forces of press-fit connector using artificial neural network(ANN)-assisted optimization method.The ANN model is established to approximate the relationship between geometric parameters and insertion-withdrawal forces,of which hyper-parameters of neural network are optimized to improve model performance.Two numerical methods are proposed for inverse designing structural parameters(Model-I)and multi-objective optimization of insertion-withdrawal forces(Model-II)of press-fit connector.In Model-I,a method for inverse designing structure parameters is established,of which an ANN model is coupled with single-objective optimization algorithm.The objective function is established,the inverse problem is solved,and effectiveness is verified.In Model-II,a multi-objective optimization method is proposed,of which an ANN model is coupled with genetic algorithm.The Pareto solution sets of insertion-withdrawal forces are obtained,and results are analyzed.The established ANN-coupled numerical optimization methods are beneficial for improving the design efficiency,and enhancing the connection reliability of the press-fit connector.
基金Supported by National Natural Science Foundation of China(Grant No.52475280)Key Laboratory Project of the Key Program of the Natural Science Basic Research Program of Shaanxi Province of China(Grant No.2025SYS-SYSZD-105)+1 种基金Natural Science Foundation of Shaanxi Province of China(Grant No.2025JC-YBQN-505)China Postdoctoral Science Foundation(Grant No.2024M752510).
文摘As space equipment become larger in size and more flexible,generalized mechanisms are being widely used in space-deployable structures.Dynamic modeling of large-scale generalized space-deployable mechanisms is challenging owing to the coupling between the deformation of flexible links and rigid body motion.This study develops a dynamic modeling method for generalized mechanisms using the local frame of the SE(3)Lie group.The model represents both rigid and flexible links within a unified Lie group setting.The expressions for the velocities of rigid links and deformation of flexible links are derived using the Lie algebra framework.The nonuniqueness of the degrees of freedom of generalized kinematic pairs is considered,and the velocity fields of kinematic pairs in different situations are expressed.The equations of motion are derived using Hamilton’s principle.Because the velocities are expressed in the local frame,the mass matrix in the equation is constant,which yields a compact and unified expression for the dynamic equation.A Lie group generalized-αtime integration method is adopted to ensure numerical stability and efficiency in simulating multibody systems with large rotations and deformations.Two numerical examples are studied to demonstrate a formulation that reflects the motion responses under varying configurations and loading conditions.This study broadens the application of the local frame of the Lie group formulation in space mechanisms and provides a new concept for dynamic modeling of generalized mechanisms.
基金Supported by National Natural Science Foundation of China(Grant No.52475280)Shaanxi Provincial Natural Science Basic Research Program(Grant No.2025SYSSYSZD-105).
文摘Robots are key to expanding the scope of space applications.The end-to-end training for robot vision-based detection and precision operations is challenging owing to constraints such as extreme environments and high computational overhead.This study proposes a lightweight integrated framework for grasp detection and imitation learning,named GD-IL;it comprises a grasp detection algorithm based on manipulability and Gaussian mixture model(manipulability-GMM),and a grasp trajectory generation algorithm based on a two-stage robot imitation learning algorithm(TS-RIL).In the manipulability-GMM algorithm,we apply GMM clustering and ellipse regression to the object point cloud,propose two judgment criteria to generate multiple candidate grasp bounding boxes for the robot,and use manipulability as a metric for selecting the optimal grasp bounding box.The stages of the TS-RIL algorithm are grasp trajectory learning and robot pose optimization.In the first stage,the robot grasp trajectory is characterized using a second-order dynamic movement primitive model and Gaussian mixture regression(GMM).By adjusting the function form of the forcing term,the robot closely approximates the target-grasping trajectory.In the second stage,a robot pose optimization model is built based on the derived pose error formula and manipulability metric.This model allows the robot to adjust its configuration in real time while grasping,thereby effectively avoiding singularities.Finally,an algorithm verification platform is developed based on a Robot Operating System and a series of comparative experiments are conducted in real-world scenarios.The experimental results demonstrate that GD-IL significantly improves the effectiveness and robustness of grasp detection and trajectory imitation learning,outperforming existing state-of-the-art methods in execution efficiency,manipulability,and success rate.
基金financial supports from the National Natural Science Foundation of China(Grant Nos.51925503&52105575)the Fundamental Research Funds for the Central Universities(Grant No.QTZX23063)+2 种基金the Aeronautical Science Foundation of China(Grant No.2022Z073081001)the Postdoctoral Fellowship Program of CPSF(Grant No.GZC20232028)the Open Research Funds of State Key Laboratory of Intelligent Manufacturing Equipment and Technology(Grant No.IMETKF2024008).
文摘The combination of advanced photoelectric detectors has rendered single-band camouflage materials ineffective,necessitating the development of infrared multispectral camouflage.However,the design and fabrication of existing works remain complex as they usually require the integration of multiscale structures.Here,we introduce phase modulation into the infrared camouflage metasurfaces with metal-dielectric-metal configuration,enabling them to achieve camouflage across more bands.Based on this strategy,a simple but effective single-layer cascaded metasurface is demonstrated for the first time to achieve low reflection at multi-wavelength lasers,low infrared radiation in atmospheric windows,and broadband thermal management.As a proof-of-concept,a 4-inch sample with a minimum linewidth of 1.8μm is fabricated using photolithography.The excellent infrared multispectral camouflage performance is verified in experiments,showing low reflectance in 0.9–1.6μm,low infrared emissivity in mid-wavelength infrared(MWIR)and long-wavelength infrared(LWIR)bands,and high absorptance at the wavelength of 10.6μm.Meanwhile,broadband high emissivity in 5–8μm can provide high-performance radiative heat dissipation.When the input power is 1.57 W·cm^(-2),the surface/radiation temperature of the metasurface decreases by 5.3℃/18.7℃ compared to the reference.The proposed metasurface may trigger further innovation in the design and application of compact multispectral optical devices.
文摘Photocatalysis is an important process in energy conversion and environmental usage because of its feasible,profitable,and environmentally safe benefits.Coordination chemistry of the CeO_(2)is gaining significant interest because its nanocomposites show unique characteristics namely optically active,wide bandgap(Eg),reversible valence states(Ce^(3+/4+)),rich defect architectures,high O_(2)storage capability,ionic conductivity,and exceptional chemical resistance.Systematically summarized the importance of synthesis methods,particle morphology,and crystal structure aiming at how to heighten the efficacy of CeO_(2)-derived hybrid heterojunction(HHJ)photocatalyst.Selection of an appropriate synthesis method and morphology of the composite materials are beneficial in inhibiting the rapid electron-hole(e^(−)-h^(+))recombination,improvement in visible light adsorption,and large generation of e^(−)-h^(+)pairs to accelerate the photocatalysts activities.Various modification approaches include elemental doping(metal/non-metal doping),heterojunction construction(lower/wide Eg semiconductors(SCD),carbon,conducting polymeric materials),imperfection engineering,and multicomponent hybrid composites.These methods assist as a valuable resource for the rational design of effective CeO_(2)-based composite photocatalysts for sustainable development owing to the enhancement of oxygen species mobility,rapid charge transfer,maximum visible light captivation and slow down the charge recombination rate with increase photogeneration of e−-h+pairs.Also examines the advancements made in CeO_(2)conjugated hybrid composites in photo-oxidation of wastewater effluents(antibiotic/organic dyes/chemical/pharmaceutical),heavy metal removal,H2 production,CO_(2)reduction,and H2O splitting applications.Subsequently,the difficulties and fundamental ideas behind several heterojunction photocatalysts encountered by CeO_(2)-based composites are examined,and future directions for their development are suggested.
基金support from the China Postdoctoral Science Foundation(No.2023M742735)the Postdoctoral Fellowship Program of CPSF,China(No.GZC20232029)+5 种基金the National Natural Science Foundation of China(No.52475530)the Shaanxi Postdoctoral Science Foundation,China(No.2023BSHEDZZ175)the Innovation Capability Support Program of Shaanxi Province,China(No.2021TD-23)the Key Industrial Chain Core Technology Research Project in Xi’an,China(No.23LLRH0029)the Natural Science Basic Research Program of Shaanxi,China(No.2024JC-YBQN-0490)the Fundamental Research Funds for the Central Universities,China(No.ZYTS24023).
文摘Silicon Carbide (SiC) wafers have been widely used in micro- and nano-devices due to their excellent optical and material properties. However, polishing SiC wafers has been challenging and inefficient, tending to cause significant surface crack and subsurface damage. This work proposed modifying SiC surface properties by ion implantation to improve machining efficiency, suppress surface crack, and reduce damage. High-energy ion implantation disrupted the SiC crystal lattice, reducing hardness and elastic modulus while increasing brittle-ductile transition depth, thus changing the removal mode from brittle fracture to plastic removal. Theoretical models of material removal rate and surface roughness were established for abrasive polishing of the SiC wafers. Polishing experiments were conducted on ion-implanted, modified SiC samples. The improvement mechanisms of ion implantation on surface damage, removal rate, morphology, and residual stress were investigated. The effect of ion implantation on the polished surface quality of SiC was investigated through orthogonal experiments. The results showed that ion implantation can significantly improve the average material removal rate of the SiC samples. Additionally, the ion-implanted samples had exhibited remarkable reductions in surface roughness, surface damage, and tensile residual stress.
基金funded by the National Natural Science Foundation of China(Nos.12363011,52275270,52275269)Natural Science Foundation of Xinjiang Uygur Autonomous Region(No.2023D01C22)+1 种基金the Tianchi Talents Program of Xinjiang,the National Key Basic Research Program of China(No.2021YFC2203501)the Xinjiang Postdoctoral Foundation.
文摘Active adjustment technology is used to solve the problem of reduced electrical performance of large reflector antennas caused by environmental factors.This technology is crucial for the operation of antennas under high-frequency working conditions.This paper proposes a full-path active adjustment strategy for dual-reflector antennas.This strategy takes into account the working mode of the adjustment mechanism under comprehensive influencing factors and achieves the optimal receiving performance at the full elevation by changing different adjustment algorithms.First,the relationship between the displacement of reflector and the wavefront phase was established based on geometric optics.Second,three adjustment algorithms of the double reflector antenna were compared and analyzed:based on the standard,the fit and the optimal parabolic surface,the calculation process of the adjustment amount was derived.An adjustment strategy model for multiple working conditions was proposed by introducing the elevation and the complexity coefficient and combining three adjustment algorithms.Finally,a finite element analysis was conducted on the dual-reflector antenna with a diameter of 110 m,and the advantages and disadvantages of different adjustment algorithms were compared.The results show that strategy model not only achieves the optimal state of the antenna at the full elevation,but also shortens the adjustment amount of the adjustment mechanism and improves the working efficiency of the antenna under various working conditions.
基金financially supported by the National Key Research and Development Program of China(2022YFC2406600 and 2020YFB2009000)the Program for Innovation Team of Shaanxi Province(2021TD-23)。
文摘Acoustofluidics is a term describing the class of phenomena in which mechanical or acoustic vibrations induce a deformation or a flow in a fluid.Many deficiencies in our understanding of these phenomena remain to be addressed,with respect to the fundamental theoretical framework as well as in numerous applications.In this regard,the frequency of external forcing is a key parameter.Owing to the low cost,substantial magnitude,and versatility associated with acoustofluidic phenomena at audible frequencies,studies of these phenomena in the audible range have emerged with increasing amount in recent years and have attracted considerable attention.However,compared with studies focusing on the ultrasonic frequency domain,critical features and information specific to audible acoustofluidics remain dispersed across many independent publications,and a systematic integration of the literature on this topic is necessary.Accordingly,this review summarizes the basic theory and methods for generating vibrations in the audible range,presents various applications thereof in biology,chemistry,and other fields,and provides a high-level overview of the current status of the topic to motivate developing interesting proposals for further research in this field of study.
基金Supported by National Natural Science Foundation of China(Grant Nos.51975118,52025121)Foundation of State Key Laboratory of Automotive Simulation and Control of China(Grant No.20210104)+1 种基金Foundation of State Key Laboratory of Automobile Safety and Energy Saving of China(Grant No.KFZ2201)Special Fund of Jiangsu Province for the Transformation of Scientific and Technological Achievements of China(Grant No.BA2021023).
文摘Four-wheel independently driven electric vehicles(FWID-EV)endow a flexible and scalable control framework to improve vehicle performance.This paper integrates the torque vectoring and active suspension system(ASS)to enhance the vehicle’s longitudinal and vertical motion control performance.While the nonlinear characteristic of the tire model leads to a relatively heavier computational burden.To facilitate the controller design and ease the load,a half-vehicle dynamics system is built and simplified to the linear-time-varying(LTV)model.Then a model predictive controller is developed by formulating the objective function by comprehensively considering the safety,energy-saving and comfort requirements.The in-wheel motor efficiency and the power loss of tire slip are treated as optimization indices in this work to reduce energy consumption.Finally,the effectiveness of the proposed controller is verified through the rapid-control-prototype(RCP)test.The results demonstrate the enhancement of the energy-saving as well as comfort on the basis of vehicle stability.
基金supported by the Civil Aerospace Technology Research Project,China(No.D010103)the National Natural Science Foundation of China(Nos.52022075 and U1937202)the National Key R&D Program of China(No.2021YFB3900300).
文摘In this paper,a multi-bus distributed Power Conditioning Unit(PCU)is proposed for the Space Solar Power Station with large scale photovoltaic(PV)array and power levels reaching MW level.In this unit,there are multiple independent PV arrays.In each PV array,there are multiple independent PV subarrays.In this paper,a V-P droop control method with adaptive droop coefficient is proposed,which modifies the droop intercept based on the bus voltage deviation and the power per unit value of the PV array.This method ensures the accuracy of bus voltage and achieves proportional distribution of power between PV arrays based on the proposed topology structure in this paper.When the load changes or the output power of the PV array fluctuates,this method can ensure that power is distributed proportionally.The principle and control method of the proposed droop control method is analyzed in this paper.The effectiveness of the method is verified through MATLAB/Simulink simulation and experiment.Simulation and experimental results show that the proposed method can achieve power distributed proportionally when load changes and PV output power fluctuates,reduce bus voltage error caused by line impedance and differences in rated power of different PV arrays,and improve the performance of PV power generation system applied to space.
基金supported by the National Natural Science Foundation of China(No.12302052)the Fundamental Research Funds for the Central Universities,China(No.XJSJ23128)the Discovery Grant of Natural Sciences and Engineering Research Council of Canada(No.RGPIN2018-05991)。
文摘This paper studies the equilibrium state and trajectory dynamics of an axially symmetric Electric solar wind sail(E-sail)at arbitrary sail angles.The E-sail is assumed operating in a heliocentric-ecliptic orbit at approximately one astronomic unit(au)from the Sun,and experiencing various dynamic disturbances like solar wind pressure,tether tension oscillations,and centrifugal forces.The study derives analytical expressions for the E-sail's equilibrium state and its maximal coning angle under small coning angle assumption.Subsequently,an improved propulsion model is developed for the E-sail in this equilibrium state.To assess the precision of these formulations,a high-fidelity E-sail dynamic model is constructed using the nodal position finite element method,where the tethers are modeled as two-noded tensile elements and the central spacecraft and remote units are simplified as lumped masses.Through thorough parametric analyses,this paper conclusively demonstrates that the operation of the E-sail at the equilibrium state can be achieved in accordance with the derived analytical prediction of the equilibrium state.Furthermore,the improved propulsion model is employed in trajectory analyses for a mission to reach the solar system's boundary.The study provides valuable insights and findings and foundation for the practical application and further advancement of the E-sail technology.
基金supported by the Natural Science Foundation of Shaanxi Province(Grant No.2024JC-YBMS-069)the Fundamental Research Funds for the Central Universities and the Innovation Fund of Xidian University(Grant Nos.ZYTS24026 and YJSJ24001).
文摘This paper presents analytical solutions for full-field radiation in magnetoelectric(ME)antennas,considering a fully magnetoelastic coupled constitutive relation.A nonlinear converse ME coupling model is established,incorporating mechanical,electric,and magnetic variables with generalized Maxwell equations.This model emphasizes the essence of ME antennas,where radiation is achieved through strain/stress-mediated coupling between different phases.The magnetic flux density and electric displacement obtained from the model are used as sources to solve the full-field radiations of ME antennas.The proposed model is validated through existing experiments and simulations,demonstrating that the radiation performance of ME antennas is strongly influenced by nonlinear magneto-elastic coupling.The material parameters and magnetic bias significantly impact the magnetic flux density and far-field radiation due to the nonlinear magnetization process.The study reveals the mechanisms behind enhanced working bandwidth and frequency tuning by examining the frequency response of the radiation impedance with material parameters.By adjusting the initial magnetization rate,saturation magnetostriction,and saturation magnetization,the radiation efficiency/gain can be increased by 340%,108%,and 112%respectively.This model enhances our understanding of the full-field radiation of ME antennas and provides a foundation for designing tunable ME antennas.
基金funded by the National Natural Science Foundation of China(NSFC,grant Nos.12363011,52275270,and 52275269)Natural Science Foundation of Xinjiang Uygur Autonomous Region(No.2023D01C22)+1 种基金the Tianchi Talents Program of Xinjiang,the National Key Basic Research Program of China(No.2021YFC2203501)the Xinjiang Postdoctoral Foundation。
文摘Active reflectors are often used to compensate the surface distortion caused by environmental factors that degrade the electromagnetic performance of large high-frequency reflector antennas.This is crucial for maintaining high gain operation in antennas.A distortion compensation method for the active reflector of a large dual-reflector antenna is proposed.A relationship is established between the surface deformation and the optical path difference for the primary reflector by geometric optics.Subsequently,employing finite element analysis,a polynomial fitting approach is used to describe the impact of adjusting points on the reflector surface based on the coordinates of each node.By standardizing the positions of various panels on the reflector,the fitting ns can be applied to the reflector panels of similar shapes.Then,based on the distribution characteristics of the primary reflector panels,the adjustment equation for the actuators is derived by the influence matrix method.It can be used to determine the adjustment amount of actuators to reduce the rms of the optical path difference.And,the least squares method is employed to resolve the matrix equation.The example of a 110 m aperture dual-reflector antenna is carried out by finite element analysis and the proposed method.The results show that the optical path difference is reduced significantly at various elevation cases,which indicates that the proposed method is effective.
基金financially National Natural Science Foundation of China (No. 62274140)Fundamental Research Funds for the Central Universities (No. 20720230030)+3 种基金Xiaomi Young Talents Program/Xiaomi Foundation, Shenzhen Science and Technology Program (No. JCYJ20230807091401003)National Key Research and Development Program of China (No. 2023YFB3208600)National Key Laboratory of Materials Behaviors and Evaluation Technology in Space Environments (No. WDZC-HGD-2022-08)Science and Technology on Vacuum Technology and Physics Laboratory Fund (No. HTKJ2023KL510008)。
文摘Real-time physiological information monitoring can predict and prevent disease, or improve treatment by early diagnosis. A comprehensive and continuous monitoring of human health requires highly integrated wearable and comfortable sensing devices. To address this need, we propose a low-cost electronic fabric-enabled multifunctional flexible sensing integration platform that includes a flexible pressure sensor for monitoring postural pressure, a humidity sensor for monitoring the humidity of the skin surface, and a flexible temperature sensor for visualizing the ambient temperature around the human body. Thanks to the unique rough surface texture, hierarchical structure, and robust electromechanical features of the MXene-modified nonwoven fabrics, the flexible pressure sensor can achieve a monitoring sensitivity of 1529.1 kPa~(-1) and a pressure range of 150 kPa, which meets the demand for human pressure detection. In addition, the unique porous structure of the fabric and the stacked multilayer structure of MXene enable the humidity sensor to exhibit extremely high monitoring sensitivity, even through clothing, and still be able to detect the humidity on the skin surface.Temperature sensors based on screen-printed thermochromic liquid crystals enable visual monitoring in the range of 0℃–65℃. Through further integration with flexible printed circuit board circuits, we demonstrate a proof-of-concept device that enables real-time monitoring of human physiological information such as physical pressure, humidity, and ambient temperature environment, suggesting that the device provides an excellent platform for the development of commercially viable wearable healthcare monitors.
文摘The objective is to design a variable structure proportional navigation law for the passive homingmissile so that the missile can hit the target with a minimum miss-distance and desired impact attitude anglewithin the required overlcad when it flies at a lower trajectory.This paper utilized the variable structure propor-tional navigation with terminal impact attitude angular constraint,and made estimation about the distance rateand distance between the missile and target,which broke the limitation of a passive homing seeker.Furthermore,the paper let the switch gain vary adaptively with time to avoid any larger initial overload.The mathematicalsimulation was completed by some studied passive homing missile's dynamic model,and the simulation resultsshowed that the navigation law of the passive homing missile can make the missile get the required miss-distance and desired impact attitude angle against tanks at lower trajectories and within the maximum overload;also this guidance law is much robust to the estimation eror of distance and distance rate.
基金supported by the National Natural Science Foundation of China(6076600161105004)+1 种基金the Guangxi Key Laboratory of Automatic Detecting Technology and Instruments(YQ14110)the Program for Innovative Research Team of Guilin University of Electronic Technology(IRTGUET)
文摘A new meta-heuristic method is proposed to enhance current meta-heuristic methods for global optimization and test scheduling for three-dimensional （3D） stacked system-on-chip （SoC） by hybridizing grey wolf optimization with differential evo- lution （HGWO）. Because basic grey wolf optimization （GWO） is easy to fall into stagnation when it carries out the operation of at- tacking prey, and differential evolution （DE） is integrated into GWO to update the previous best position of grey wolf Alpha, Beta and Delta, in order to force GWO to jump out of the stagnation with DE＇s strong searching ability. The proposed algorithm can accele- rate the convergence speed of GWO and improve its performance. Twenty-three well-known benchmark functions and an NP hard problem of test scheduling for 3D SoC are employed to verify the performance of the proposed algorithm. Experimental results show the superior performance of the proposed algorithm for exploiting the optimum and it has advantages in terms of exploration.
基金Supported by the National Natural Science Funds for Distinguished Young Scholar of China(Grant No.52025121)National Natural Science Foundation of China(Grant Nos.51975118,52002066).
文摘Many surveys on vehicle traffic safety have shown that the tire road friction coefficient(TRFC)is correlated with the probability of an accident.The probability of road accidents increases sharply on slippery road surfaces.Therefore,accurate knowledge of TRFC contributes to the optimization of driver maneuvers for further improving the safety of intelligent vehicles.A large number of researchers have employed different tools and proposed different algorithms to obtain TRFC.This work investigates these different methods that have been widely utilized to estimate TRFC.These methods are divided into three main categories:off-board sensors-based,vehicle dynamics-based,and data-driven-based methods.This review provides a comparative analysis of these methods and describes their strengths and weaknesses.Moreover,some future research directions regarding TRFC estimation are presented.
文摘Shearer and hydraulic support are matching equipments. To increase the operating speed of the shearer, the following speed of hydraulic support must be increased. This means increasing the volume of flow from emulsion power station. Analyzing the operating characteristics of hydraulic supports, the number of simultaneously operating supports is obtained by means of pressure parameter and time history at a certain time, which is a theory base for development of control system to multi-pump emulsion power station.
基金supported by the National Natural Science Foundation of China(51702249,51602252,61741406)the China Postdoctoral Science Foundation(2017M613065)the Shaanxi Province Science Foundation(2017JQ5072)
文摘New lead-free ferroelectric(0.94-x)BioNaTiO-0.06 BaTiOSrTiNbO(BNBT-STN,x = 0 and 0.2)are synthesized by using a solid state reaction process. In this work, an obvious evolution of dielectric relaxation behavior and slim P-E hysteresis loops with high Pmax and low Pr is observed for BNBT-0.2 STN,indicating the dominant of ergodic relaxor phase with dynamic polar nano-regions(PNRs). A relatively large recoverable energy density(Wrec = 1.17 J/cm~3) with high energy efficiency(η= 91%) is obtained. Furthermore, it shows small variation(9%) in the temperature range of 30-150 ℃ and fatigue-free behavior,which can be attributed to the absence of ferroelectric domain in the relaxor phase. The achievement of these characteristics provides that tailoring by B-site vacancies is a potential route when designing a new energy-storage system for BNT-based relaxor ferroelectric materials.
