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A Novel On-Site-Real-Time Method for Identifying Characteristic Parameters Using Ultrasonic Echo Groups and Neural Network

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Chinese Journal of Mechanical Engineering 2024年第1期37卷 215-228页

作者： Shuyong Duan Jialin Zhang Heng Ouyang Xu Han Guirong Liu state key laboratory of reliability and intelligence of electrical equipment Hebei University of TechnologyTianjin 300401China Department of Aerospace Engineering and Engineering Mechanics University of CincinnatiCincinnati 45221USA

On-site and real-time non-destructive measurement of elastic constants for materials of a component in a in-service structure is a challenge due to structural complexities,such as ambiguous boundary,variable thickness,nonuniform material *** work develops for the first time a method that uses ultrasound echo groups and artificial neural network(ANN)for reliable on-site real-time identification of material *** use of echo groups allows the use of lower frequencies,and hence more accommodative to structural *** train the ANNs,a numerical model is established that is capable of computing the waveform of ultrasonic echo groups for any given set of material properties of a given *** waveform of an ultrasonic echo groups at an interest location on the surface the structure with material parameters varying in a predefined range are then computed using the numerical *** results in a set of dataset for training the ANN *** the ANN is trained,the material parameters can be identified simultaneously using the actual measured echo waveform as input to the *** tests have been conducted both numerically and experimentally to evaluate the effectiveness and accuracy of the currently proposed *** results show that the maximum identification error of numerical example is less than 2%,and the maximum identification error of experimental test is less than 7%.Compared with currently prevailing methods and equipment,the proposefy the density and thickness,in addition to the elastic ***,the reliability and accuracy of inverse prediction is significantly ***,it has broad applications and enables real-time field measurements,which has not been fulfilled by any other available methods or equipment.

关键词： Parameter identification Ultrasonic echo group High-precision modeling Artificial neural network NDT

Coexistence behavior of asymmetric attractors in hyperbolic-type memristive Hopfield neural network and its application in image encryption

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Chinese Physics B 2024年第3期33卷 302-315页

作者：李晓霞何倩倩余天意才壮徐桂芝 key laboratory of Electromagnetic Field and electrical Apparatus reliability of Hebei Province Hebei University of TechnologyTianjin 300130China state key laboratory of reliability and intelligence of electrical equipment Hebei University of TechnologyTianjin 300130China School of Life Science & Health Engineering Hebei University of TechnologyTianjin 300130China

The neuron model has been widely employed in neural-morphic computing systems and chaotic *** study aims to develop a novel circuit simulation of a three-neuron Hopfield neural network(HNN)with coupled hyperbolic memristors through the modification of a single coupling connection *** bistable mode of the hyperbolic memristive HNN(mHNN),characterized by the coexistence of asymmetric chaos and periodic attractors,is effectively demonstrated through the utilization of conventional nonlinear analysis *** techniques include bifurcation diagrams,two-parameter maximum Lyapunov exponent plots,local attractor basins,and phase trajectory ***,an encryption technique for color images is devised by leveraging the mHNN model and asymmetric structural *** method demonstrates significant benefits in correlation,information entropy,and resistance to differential attacks,providing strong evidence for its effectiveness in ***,an improved modular circuit design method is employed to create the analog equivalent circuit of the memristive *** correctness of the circuit design is confirmed through Multisim simulations,which align with numerical simulations conducted in Matlab.

关键词： hyperbolic-type memristor Hopfield neural network(HNN) asymmetric attractors image encryption

Machine learning for parameters diagnosis of spark discharge by electro-acoustic signal

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Plasma Science and Technology 2024年第8期26卷 64-72页

作者：熊俊卢诗宇刘晓明周文俊查晓明裴学凯 state key laboratory of Power Grid Environmental Protection School of Electrical Engineering and AutomationWuhan UniversityWuhan 430072People’s Republic of China state key laboratory of reliability and intelligence of electrical equipment Hebei University of TechnologyTianjin 300131People’s Republic of China

Discharge plasma parameter measurement is a key focus in low-temperature plasma *** diagnostics often require costly equipment,whereas electro-acoustic signals provide a rich,non-invasive,and less complex source of discharge *** study harnesses machine learning to decode these *** establishes links between electro-acoustic signals and gas discharge parameters,such as power and distance,thus streamlining the prediction *** building a spark discharge platform to collect electro-acoustic signals and implementing a series of acoustic signal processing techniques,the Mel-Frequency Cepstral Coefficients(MFCCs)of the acoustic signals are extracted to construct the *** machine learning models(Linear Regression,k-Nearest Neighbors,and Random Forest)are introduced and applied to the predictors to achieve real-time rapid diagnostic measurement of typical spark discharge power and discharge *** models display impressive performance in prediction precision and fitting *** them,the k-Nearest Neighbors model shows the best performance on discharge power prediction with the lowest mean square error(MSE=0.00571)and the highest R-squared value(R^(2)=0.93877).The experimental results show that the relationship between the electro-acoustic signal and the gas discharge power and distance can be effectively constructed based on the machine learning algorithm,which provides a new idea and basis for the online monitoring and real-time diagnosis of plasma parameters.

关键词： discharge plasma plasma real-time diagnosis electro-acoustic signal machine learning acoustic signature

Improvement of the piezoelectricity of PVDF-HFP by CoFe_(2)O_(4)nanoparticles

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Nano Materials Science 2024年第2期6卷 201-210页

作者： Dan Lei Ning Hu Liangke Wu Alamusi Huiming Ning Yang Wang Zhaonan Jin Yaolu Liu College of Aerospace Engineering Chongqing UniversityChongqing400044China state key laboratory of reliability and intelligence electrical equipment School of Mechanical EngineeringHebei University of TechnologyTianjin300401China

High piezoelectric composite films composed of poly(vinylidene fluoride-co-hexafluoropropylene)(PVDF-HFP)and ferromagnetic cobalt ferrite(CoFe_(2)O_(4))(0.00 wt%to 0.2 wt%)are prepared by a solution casting method accompanied by uniaxial stretching and high electric field *** decisive effect of the poling electric field on the power generating capability was confirmed by the *** pure PVDF-HFP films,when the maximum electric field Emax is 120 MV/m,the calibrated open circuit voltage reaches 2.93 V,which is much higher than those poled at lower electric fields(70 MV/m:1.41 V;90 MV/m:2.11 V).Furthermore,the addition of CoFe_(2)O_(4)also influences the piezoelectricity *** the samples containing 0.15 wt%CoFe_(2)O_(4),the calibrated open circuit voltage increases to the maximum value of 3.57 ***,the relative fraction of theβ-phase and the crystallinity degree are 99%and 48%,*** effects of CoFe_(2)O_(4)nanoparticles on initial crystallization,uniaxial stretching and high electric field poling are investigated by XRD,FTIR and DSC.

关键词： PVDF-HFP CoFe_(2)O_(4)nanoparticles Piezoelectricity Nanocomposite

Adaptive 5G-and-beyond network-enabled interpretable federated learning enhanced by neuroevolution

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Science China(Information Sciences) 2024年第7期67卷 107-132页

作者： Bin CAO Jianwei ZHAO Xin LIU Yun LI state key laboratory of reliability and intelligence of electrical equipment Hebei University of Technology School of Artificial intelligence Hebei University of Technology School of Economics and Management Hebei University of Technology Industrial Artificial intelligence Centre Shenzhen Institute for Advanced StudyUniversity of Electronic Science and Technology of China

Mobile telemedicine systems based on the next-generation communication will significantly enhance deep fusion of network automation and federated learning(FL), but data privacy is a paramount issue in sectors like healthcare. This work hence considers FL augments 5G-and-beyond networks by training deep learning(DL) models without the need to exchange raw data. The substantial communication loads imposed on by extensive parameters involved in DL models are managed through adaptive scheduling mechanisms effectively. To address the opaque nature of DL models and to improve the interpretability of FL models, we introduce a convolutional fuzzy rough neural network specifically designed for medical image processing. We also develop a multiobjective memetic evolutionary algorithm to streamline and optimize the neural network architectures. Our comprehensive FL framework integrates smart scheduling, interpretable fuzzy rough logic,and neuroevolution. This framework is shown to improve communication efficiency, increase interpretability of diagnosis with protected privacy, and generate low-complexity neural architectures.

关键词： 5G-and-beyond network interpretable federated learning mobile telemedicine system fuzzy rough set theory neuroevolution

Study on surface discharge of nonlinear conductive epoxy resin/SrTiO3 composites in 80–300 K temperature zone

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High Voltage 2024年第1期9卷 117-126页

作者： Yunqi Xing Bin Wang Mingyang Wang Jiakai Chi Peng Jia Rongjin Huang state key laboratory of reliability and intelligence of electrical equipment Hebei University of TechnologyTianjinChina key laboratory of Electormagnetic Field and electrical Apparatus reliability of Hebei Province Hebei University of TechnologyTianjinChina key laboratory of Special Machine and High Voltage Apparatus(Ministry of Education) Shenyang University of TechnologyShenyangChina state Grid Tianjin High Voltage Company TianjinChina China Energy Engineering Group Tianjin Electric Power Design Institute Co. Ltd.TianjinChina CAS key laboratory of Cryogenics Technical Institute of Physics and ChemistryBeijingChina

Bisphenol F epoxy resin(EP)is often used in terminal current lead insulation of superconducting equipment because of its good insulation performance,high mechanical strength,good toughness at cryogenic temperatures,and resistance to cold shock and heat ***,due to the wide temperature range of 80–300 K and the strong electric field,the EP-N_(2)interface is prone to surface flashover,resulting in terminal insulation *** improve the reliability of the current lead insulation,non-linear conductive EP/strontium titanate(SrTiO_(3))composites were prepared by modification with nano *** changes of dielectric,surface discharge,flashover,and trap distribution characteristics of composite materials were studied,and the mechanism of SrTiO_(3)on the surface flashover of composite materials was *** results show that the conductivity of the composite increases with the rise of SrTiO_(3)filling content,and the amplitude of improvement is greater under the strong electric field,showing a more significant *** composite has a lower trap energy level and a greater number of shallow traps compared to pure EP,which accelerates surface charge detrapping and reduces charge accumulation,effectively enhancing the discharge and surface flashover voltage of the composite.

关键词： composites composite insulation

Arbitrary topological charge vortex beams from carbon dots random lasers

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Rare Metals 2024年第8期43卷 3844-3853页

作者： Xiang-Dong Wang Xiao-Bo Mi Jiu-Ru He Feng-Ying Ma Jun-Qiao Wang Li Song Yong-Qiang Zhang Si-Yu Lu Yong-Sheng Hu School of Physics and Microelectronics Zhengzhou UniversityZhengzhou 450001China state key laboratory of reliability and intelligence of electrical equipment and Tianjin key laboratory of Electronic Materials and Devices School of Electronics and Information EngineeringHebei University of TechnologyTianjin 300401China Green Catalysis Center College of ChemistryZhengzhou UniversityZhengzhou450001China

Vortex beams have attracted great attention due to their promising applications in the fields of high-capacity optical communication,optical micromanipulation,and quantum information ***,we demonstrate vortex beams with flexible control of the topological charge and modes in a carbon dots random laser for the first *** beams with different types,including the Laguerre-Gaussian(LG),Bessel-Gaussian(BG),LG-superposition,and polarized vortex beams with topological charges up to 50,have been successfully ***,vortex beams can be well realized in carbon dots random lasers with different emission wavelengths covering from 465 to 612 *** work would not only enrich the types of vortex laser,especially for solution-processable lasers,but also provide a new route to realizing multicolor and wavelength-tunable vortex lasers.

关键词： Carbon dots Random lasers Vortex beam Topological charge Spatial light modulator

Regulating electrochemical performances of lithium battery by external physical field

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Rare Metals 2024年第6期43卷 2391-2417页

作者： Shi-Kang Wang Shuai Wu Yi-Cheng Song Hassanien Gomaa Cui-Hua An Qi-Bo Deng Ning Hu School of Mechanical Engineering School of Materials Science and EngineeringHebei University of TechnologyTianjin 300401China Shanghai key laboratory of Mechanics in Energy Engineering Shanghai 200444China Department of Chemistry Faculty of ScienceAl-Azhar UniversityAssiut 71524Egypt Tianjin key laboratory of Power Transmission and Safety Technology for New Energy Vehicles Tianjin 300401China state key laboratory of reliability and intelligence electrical equipment Key Laboratory of Advanced Intelligent Protective Equipment TechnologyMinistry of EducationHebei University of TechnologyTianjin 300130China

Lithium batteries have always played a key role in the field of new energy ***,non-controllable lithium dendrites and volume dilatation of metallic lithium in batteries with lithium metal as anodes have limited their ***,a large number of studies have shown that the electrochemical performances of lithium batteries can be enhanced through the regulation of external physical ***,it significantly hinders the growth of lithium dendrites and promoting the reaction *** review summarizes recent innovations in the investigation of various physical fields of lithium *** application of magnetic field in the synthesis of lithium battery electrode materials is *** influence factors and regulation mechanism of various physical fields on the electrochemical performance of lithium batteries are reviewed *** addition,the current research status and existing challenges,along with future directions for the evolution of lithium batteries,are minutely discussed and *** strategies for the further evolution of lithium batteries have also been provided.

关键词： Lithium battery External field assist Reaction kinetics Lithium dendrite

Effect of nucleating agents on the electrical properties of cross-linked polyethylene under tensile stress

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High Voltage 2024年第2期9卷 429-439页

作者： Yunqi Xing Jiahao Liu Jingang Su Junwei Zha Guochang Li Ze Guo Xiaozhen Zhao Mengjia Feng state key laboratory of reliability and intelligence of electrical equipment Hebei University of TechnologyTianjinChina Electric Power Research Institute of state Grid Hebei Electric Power Supply Co. Ltd.ShijiazhuangChina Beijing Advanced Innovation Center for Materials Genome Engineering School of Chemistry and Biological EngineeringUniversity of Science&Technology BeijingBeijingChina Institute of Advanced electrical Materials Qingdao University of Science and TechnologyQingdaoChina

During the operation of high-voltage cables,external stress and residual stress can affect the aggregated structure of insulating materials and lead to significant deterioration in their electrical *** investigate the evolution characteristics of the electrical properties of cross-linked polyethylene(XLPE)under mechanical stress,this paper ex-plains the relationship between the aggregated structure of XLPE and its electrical properties and proposes a method for improving insulation performance under me-chanical *** results show that metallocene polyethylene used as a nucleating agent can promote crystallisation through heterogeneous nucleation and increase Young's modulus by non-uniform nucleation,increasing crystallinity and reducing interplanar spacing,resulting in more complete crystal forms and reduced damage to the aggregated structure during the tensile *** nucleating agent modification,the XLPE crystallisation becomes more uniform,and interfacial adhesion forces *** weakened interface damage process between the amorphous and crystalline regions under tensile stress effectively inhibits the process of molecular chain polarisation turning and reduces trap *** modified XLPE crystal structure shows a tendency towards densification and enhanced molecular chain interactions,which can reduce the damage to the aggregated structure under tensile stress,while the reduced free volume inside the material and the shortened average free path of carriers can weaken the damage of high-energy electrons to molecular chains,thereby inhibiting the process of electrical tree *** results show that nucleating agents have great potential for maintaining the stable operation of XLPE cables under mechanical stress.

关键词： stress electrical damage