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Tsinghua Science and Technology 2023年第4期28卷 673-685页

作者： Qiuju zhang Hongtao zhang Keming Zhou le zhang College of Computer Science Sichuan UniversityChengdu 610065China August International Ltd. HoddesdonEN110EEUK Key Laboratory of Systems Health Science of Zhejiang Province Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou 310024China

With the development of computers,artificial intelligence,and cognitive science,engagement in deep communication between humans and computers has become increasingly ***,affective computing is a current hot research ***,this study constructs a Physiological signal-based,Mean-threshold,and Decision-level fusion algorithm(PMD)to identify human emotional ***,we select key features from electroencephalogram and peripheral physiological signals,and use the mean-value method to obtain the classification threshold of each participant and distinguish individual ***,we employ Gaussian Naive Bayes(GNB),Linear Regression(LR),Support Vector Machine(SVM),and other classification methods to perform emotion ***,we improve the classification accuracy by developing an ensemble *** experimental results reveal that physiological signals are more suitable for emotion recognition than classical facial and speech *** proposed mean-threshold method can solve the problem of individual differences to a certain extent,and the ensemble learning model we developed significantly outperforms other classification models,such as GNB and LR.

关键词： electroencephalogram(EEG) peripheral physiological signals machine learning emotion recognition multimodal fusion

Synthesis of hierarchically porous carbon materials by zinc salts-assisted carbonization of biomass and organic solid wastes

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Particuology 2024年第1期84卷 45-52页

作者： le-le zhang lei Tong Yanwei Ding Wanqun zhang Hai-Wei Liang Hefei National Research Center for Physical Sciences at the Microscale Department of ChemistryUniversity of Science and Technology of ChinaHefei230026China

Hierarchically porous carbons(HPCs)with multimodal pores have attracted considerable attention due to their unique physical and chemical properties and various application potentials in heterogeneous catalysis,environmental treatment,and energy storage and ***,we report a general and simple zinc salts-assisted method for the synthesis of HPCs with varied porosity and chemical func-tionalities by the direct carbonization of diverse biomass and *** the carbonization,zinc salts are thermally decomposed into nanoparticles that serve as in-situ templates to introduce nanopores in *** prepared HPCs exhibit high specific surface areas(up to 2432 m2 g-1),large pore volumes(up to 4.30 cm^(3)g^(-1)),and broad pore size ***,the zinc salts can be recovered and recycled,supporting the sustainable production of HPCs on large *** prepared HPCs-supported catalysts with atomically dispersed metal sites exhibit promising electrocatalytic performance for the oxygen reduction reaction.

关键词： Hierarchical porous carbon Zinc salts Biomass Wastes Electrocatalysis

（Bmim）Br3 as a New Reagent for Regioselective Monobromination of Phenols and Several Activated Aromatics under Solvent-free Conditions

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Chinese Journal of Chemistry 2005年第11期23卷 1537-1540页

作者： le, zhang-Gao Department of Applied Chemistry East China Institute of Technology Fuzhou Fujian 344000 China Department of Chemistry Zhejiang University Xixi Campus Hangzhou Zhejiang 310028 China Ningbo Institute of Technology of Zhejiang University Ningbo Zhejiang 315100 China

Reaction of phenols and activated aromatics with 1-butyl-3-methylimidazolium tribromide [（Bmim）Br3] under solvent-free conditions gave selectively the corresponding monobromination products in excellent yields.

关键词： activated aromatics regioselective (Bmim)Br3

Optimization on the Crosswind Stability of Trains Using Neural Network Surrogate Model

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Chinese Journal of Mechanical Engineering 2021年第4期34卷 208-224页

作者： le zhang Tian Li Jiye zhang Ronghuan Piao State Key Laboratory of Traction Power Southwest Jiaotong UniversityChengdu 610031China

Under the influence of crosswinds,the running safety of trains will decrease sharply,so it is necessary to optimize the suspension parameters of *** paper studies the dynamic performance of high-speed trains under cross-wind conditions,and optimizes the running safety of train.A computational fluid dynamics simulation was used to determine the aerodynamic loads and moments experienced by a train.A series of dynamic models of a train,with different dynamic parameters were constructed,and analyzed,with safety metrics for these being ***,a surrogate model was built and an optimization algorithm was used upon this surrogate model,to find the minimum possible values for:derailment coefficient,vertical wheel-rail contact force,wheel load reduction ratio,wheel lateral force and overturning *** were 9 design variables,all associated with the dynamic parameters of the *** the train was running with the speed of 350 km/h,under a crosswind speed of 15 m/s,the benchmark dynamic model performed *** derailment coefficient was *** vertical wheel-rail contact force was 133.30 *** wheel load reduction rate was *** wheel lateral force was 85.67 kN,and the overturning coefficient was *** optimization,under the same running conditions,the metrics of the train were 0.268,100.44 kN,0.474,34.36 kN,and 0.421,*** paper show that by combining train aerodynamics,vehicle system dynamics and many-objective optimization theory,a train’s stability can be more comprehensively analyzed,with more safety metrics being considered.

关键词： Safety Surrogate model Optimization High-speed train Crosswind

Map Reconstruction of Radio Observations with Conditional Invertible Neural Networks

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Research in Astronomy and Astrophysics 2023年第7期23卷 126-138页

作者： Haolin zhang Shifan Zuo le zhang School of Physics and Astronomy Sun Yat-sen UniversityZhuhai 519082China CSST Science Center for the Guangdong-Hong Kong-Macao Greater Bay Area Zhuhai 519082China Department of Astronomy Tsinghua UniversityBeijing 100084China Peng Cheng Laboratory Shenzhen 518000China

In radio astronomy,the challenge of reconstructing a sky map from time ordered data is known as an inverse *** map-making techniques and gridding algorithms are commonly employed to address this problem,each offering its own benefits such as producing minimum-variance ***,these approaches also carry limitations such as computational inefficiency and numerical instability in map-making and the inability to remove beam effects in grid-based *** overcome these challenges,this study proposes a novel solution through the use of the conditional invertible neural network(cINN)for efficient sky map *** the aid of forward modeling,where the simulated time-ordered data(TODs)are generated from a given sky model with a specific observation,the trained neural network can produce accurate reconstructed sky *** the Five-hundred-meter Aperture Spherical radio Telescope as an example,cINN demonstrates remarkable performance in map reconstruction from simulated TODs,achieving a mean squared error of2.29±2.14×10^(-4)K^(2),a structural similarity index of 0.968±0.002,and a peak signal-to-noise ratio of26.13±5.22 at the 1σ***,by sampling in the latent space of cINN,the reconstruction errors for each pixel can be accurately quantified.

关键词： methods:data analysis methods:numerical methods:statistical

Extraction of full energy peak of ^(137)Cs from in situ NaI(Tl)gamma-ray spectrum

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Nuclear Science and Techniques 2016年第4期27卷 53-59页

作者： le-le zhang Nan-Ping Wang Bao-Chuan Li School of Geophysics and Information Technology China University of Geosciences

A levenberg–Marquardt Gaussian fitting algorithm has been used for analyzing the overlap of three peaks(the 583-ke V peak of^(208)Tl, the 609-ke V peak of214 Bi, and the 662-ke V peak of^(137)Cs) using an in situ Na I(Tl) scintillation spectrometer. The algorithm, in addition,was compared with a genetic algorithm used for multiple deconvolution. The three fitted peak areas(583, 609, and662 ke V) were calculated from the measured gamma-ray spectra obtained from a simulation experiment in which a^(137) Cs source was buried at different soil depths(from 18 to38 cm). The application of the levenberg–Marquardt algorithm yielded similar results compared to the genetic algorithm. A lack-of-fit test showed that the fitting is good when the instrumental noise levels were estimated from replicated analyses. The relative fitting error of the total net area and the residual standard deviation were within 5 %and 0.04, respectively, and the goodness of the fitting was better than 0.98. While the methods used in this paper give high performance, the results may lead to incorrect estimation when the signal-to-noise ratio is smaller than-30 d B. This study is useful for the determination of radioactive specific activity of^(137) Cs by in situ spectrometry.

关键词： 137Cs γ射线谱 Marquardt算法全能峰 Gaussian 拟合算法提取相对拟合误差

Two types of dynamic cool coronal structures observed with STEREO and Hinode

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Research in Astronomy and Astrophysics 2009年第12期9卷 1368-1376页

作者： Jun zhang le-Ping Li Key Laboratory of Solar Activity National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China

Solar coronal loops show significant plasma motions during their formation and eruption stages. Dynamic cool coronal structures, on the other hand, are often observed to propagate along coronal loops. We report on the discovery of two types of dynamic cool coronal structures, and characterize their fundamental properties. Using the EUV 304 A images from the Extreme UltraViolet Imager （EUVI） telescope on the Solar TErrestrial RElation Observatory （STEREO） and the Ca Ⅱ filtergrams from the Solar Optical Telescope （SOT） instrument on Hinode, we study the evolution of an EUV arch and the kinematics of cool coronal structures. The EUV 304A observations show that a missile-like plasmoid moves along an arch-shaped trajectory, with an average velocity of 31 km s^- 1. About three hours later, a plasma arch forms along the trajectory, subsequently the top part of the arch fades away and disappears; meanwhile the plasma belonging to the two legs of the arch flows downward to the arch＇s feet. During the arch formation and disappearance, SOT Ca Ⅱ images explore dynamic cool coronal structures beneath the arch. By tracking these structures, we classify them into two types. Type I is thread- like in shape and flows downward with a greater average velocity of 72 km s-l; finally it combines with a loop fibril at a chromospheric altitude. Type Ⅱ is shape-transformable and sometimes rolling as it flows downward with a smaller velocity of 37 km s-1, then disappears insularly in the chromosphere. It is suggested that the two types of structures are possibly controlled by different magnetic configurations.

关键词： Sun: chromosphere -- Sun: UV radiation -- Sun: activity

Real-time and visible monitoring of stress distribution using organic mechanoresponsive luminogen

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Science China(Technological Sciences) 2021年第12期64卷 2586-2594页

作者： zhang le zhang Zhe LIN Hong CHEN Gang CHEN Xu School of Chemical Engineering and Technology Tianjin UniversityTianjin 300350China Tianjin Key Laboratory of Chemical Process Safety and Equipment Technology Tianjin 300350China

A real-time and visible stress monitoring method based on a pure organic mechanoresponsive luminogen(MRL)was proposed in this work.1,1,2,2-tetrakis(4-nitrophenyl)ethene(TPE-4 N)could produce ultrasensitive and visible mechanoresponsive *** specimens were coated with a uniform TPE-4 N film,wherein mechanical deformation was transformed into visible *** tests were conducted to determine the calibration relationship between the stress value and fluorescence *** accuracy of stress measured using the organic MRL method was investigated on single-edge notched tension *** show that the stress distribution obtained using the proposed method agrees well with that calculated using ANSYS *** organic MRL method may open up new opportunities for large-scale,full-field,on-site monitoring of stress distribution in complicated structural components.

关键词： stress measurement real-time monitoring organic mechanoluminescence

Effect of nano-oxide layers on the magnetoresistance of ultrathin permalloy films

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Rare Metals 2009年第6期28卷 624-628页

作者： WANG le zhang Jinzhong WANG Lijin Department of Materials Physics and Chemistry University of Science and Technology Beijing Beijing 100083 China

Ta/NiFe/Ta ultrathin films with and without nano-oxide layers （NOLs） were prepared by magnetron sputtering followed by a vacuum annealing process. The influence of NOLs on the magnetoresistance （MR） ratio of ultrathin permalloy films was studied. The results show that the influence of grain size and textures on the MR ratio becomes weak when the thickness of the NiFe layer is below 15 nm. A higher MR ratio was observed for the thinner （〈 15 nm） NiFe film with NOLs. The MR ratio of a 10 nm NiFe film can be remarkably enhanced by NOLs. The enhanced MR ratio for these ultrathin films can be attributed to the enhanced specular reflection of conduction electrons.

关键词： material surface and interface anisotropic magnetoresistance magnetron sputtering nano oxide layer NiFe

Fault Detection for Motor Drive Control System of Industrial Robots Using CNN-LSTM-based Observers

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CES Transactions on Electrical Machines and Systems 2023年第2期7卷 144-152页

作者： Tao Wang le zhang Xuefei Wang the School of Intelligent Equipment Engineering Wuxi Taihu UniversityJiangsu International Cooperation Laboratory of 6G Network and Big Data Intelligent ApplicationWuxi214064China the School of Intelligent Equipment Engineering Wuxi Taihu UniversityWuxi214064China

The complex working conditions and nonlinear characteristics of the motor drive control system of industrial robots make it difficult to detect *** this paper,a deep learning-based observer,which combines the convolutional neural network(CNN)and the long short-term memory network(LSTM),is employed to approximate the nonlinear driving control *** layers are introduced to extract dynamic features of the data,whereas LSTM layers perform time-sequential prediction of the target *** terms of application,normal samples are fed into the observer to build an offline prediction model for the target *** trained CNN-LSTM-based observer is then deployed along with the target system to estimate the system *** fault detection can be realized by analyzing the ***,an application of the proposed fault detection method to a brushless DC motor drive system is given to verify the effectiveness of the proposed *** results indicate the impressive fault detection capability of the presented method for driving control systems of industrial robots.

关键词： Fault detection Motor drive control system Deep learning CNN-LSTM Industrial robot