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science china({2. sciences) 2012年第1期55卷 90-97页

作者： rao lei1&yang dongxiao1,2.1department of information science and electronic engineering,Zhejiang {2.,hangzhou 31002.,china 2.esearch Center for Terahertz Technology,Zhejiang {2.,hangzhou 31002.,china 1. department of information {2. and electronic engineering Zhejiang University Hangzhou 310027 China2. Research Center for Terahertz Technology Zhejiang University Hangzhou 310027 China

Terahertz transmission spectra through both single-layered and double-layered sub-wavelength metal hole arrays were calculated using rigorous mode-matching *** dispersion relations of the single-layered and double-layered metal hole arrays were obtained by FDTD *** are three anomalous peaks in the spectrum of the double-layered metal hole array,which arise from the three surface electromagnetic modes appearing in the dispersion *** comparing the transmission spectra and the dispersion relations of the single-layered and double-layered metal hole arrays,it was found that the two surface electromagnetic modes at higher frequencies are introduced by the single-layered metal hole array,while the one at lower frequencies is introduced by the double-layered metal hole *** validity of the analysis was qualitatively verified by the experimental *** structure can be finely designed for potential applications,such as wideband filtering.

关键词： surface electromagnetic modes double-layered metal hole array terahertz

Influence of modulation ratio on structure and properties of nanoscale ZrB_2.ZrAlN multilayered coatings

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science china(Technological sciences) 2010年第3期53卷 772-775页

作者： LI DeJun 1,KANG YuanBin 1,DONG lei 1,DENG XiangYun 1,LIU Hao 2.&SUN XueLiang 2.1College of Physics and {2. information science,Tianjin Normal university,Tianjin 300387,china 2.department of Mechanical&Materials engineering,university of Western Ontario,London ON,Canada 1. College of Physics and electronic information {2. Tianjin Normal University Tianjin 300387 China2. Department of Mechanical & Materials Engineering University of Western Ontario London ON Canada

ZrB2.ZrAlN multilayered coatings with various modulation ratios(t ZrB2.t ZrAlN)and constant modulation periods were prepared by magnetron sputtering system at room ***,XRD,surface profiler and nano-indenter were employed to investigate the influences of tZ rB 2.tZrAlNon the microstructure and mechanical properties of the *** interfaces and nanoscale multilayered modulation were confirmed by *** multilayer with modulation period of 40 nm and ratio of 3:1 displayed the highest hardness(36.4 GPa)and critical fracture load(76.477 mN)with lower *** polycrystalline structure and multilayered modulate structure were directly responsible for the enhanced mechanical properties.

关键词： ZrB2.ZrAlN multilayered coating magnetron sputtering modulation ratio nanoscale

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Multi-channel radar array design method and algorithm

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science china({2. sciences) 2010年第7期53卷 1470-1480页

作者： SU Yi1*, ZHU YuTao1, YU WenXian2. XU HongBo1 & lei WenTai1 1School of electronic {2. and engineering, National university of Defense Technology, Changsha 410073, china 2.chool of Electric, information and Electrical engineering, Shanghai Jiao Tong university, Shanghai 2.02.0, china 1. School of electronic science and {2. National University of Defense Technology Changsha 410073 China2. School of Electric Information and Electrical Engineering Shanghai Jiao Tong University Shanghai 200240 China

The array design of radar antenna is no more a new problem at all. Nevertheless, the array design of multi-channel radar, especially that of MIMO (multiple-input multiple-output) radar, is a new problem. The performance of space diversion and spatial sampling of target scattering are dependent on the array design of MIMO radar, and consequently, which in turn will determine the performances of target parameter estimation, DOA, and imaging. In this paper, commencing with target scattering model, T/R signal model of MIMO radar, and spatial sampling ability for this system are analyzed. Conceptually, under the far field condition, spatial convolution principle determines the array design theory. Based on this idea, array design method and also algorithm are proposed in this paper.

关键词： MIMO-radar antenna arrays DOA estimation spatial sampling imaging algorithm

Adaptive detection for distributed targets in Gaussian noise with rao and Wald tests

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science china({2. sciences) 2012年第6期55卷 1290-1300页

作者： SHUAI XiaoFei,KONG LingJiang & yang JianYu School of electronic {2.,university of electronic science and Technology of china,Chengdu 610054,china 1. School of electronic engineering University of Electronic Science and Technology of China Chengdu 610054 China

The problem of adaptively detecting a range distributed target or targets in Gaussian interference is considered in this *** is assumed that a set of secondary data is ***,we derive the adaptive rao and Wald tests with one-step detection algorithm,and find that both of them are of the same asymptotic performance as the GLRT ***,the rao and Wald tests are derived by resorting to the two-step design *** our surprise,our derivations show that all the rao,Wald and GLR tests in the two-step design strategy are ***,the property assessments are *** is shown that these new detectors guarantee CFAR property with respect to the Gaussian ***,simulation results show that these results are accurate.

关键词： rao and Wald tests adaptive detection distributed targets maximum likelihood estimator

Convolution-Transformer for Image Feature Extraction

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Computer Modeling in engineering & sciences 2024年第10期141卷 87-106页

作者： Lirong Yin lei Wang Siyu Lu Ruiyang Wang Youshuai yang Bo yang Shan Liu Ahmed AlSanad Salman A.AlQahtani Zhengtong Yin Xiaolu Li Xiaobing Chen Wenfeng Zheng department of Geography and Anthropology Louisiana State UniversityBaton RougeLA70803USA School of Automation University of Electronic Science and Technology of ChinaChengdu610054China College of Computer and information sciences King Saud UniversityRiyadh11574Saudi Arabia College of Resources and Environmental engineering Key Laboratory of Karst Georesources and Environment(Guizhou University)Ministry of EducationGuiyang550025China School of Geographical sciences Southwest UniversityChongqing400715China School of Electrical and Computer engineering Louisiana State UniversityBaton RougeLA70803USA

This study addresses the limitations of Transformer models in image feature extraction,particularly their lack of inductive bias for visual *** to Convolutional Neural Networks(CNNs),the Transformers are more sensitive to different hyperparameters of optimizers,which leads to a lack of stability and slow *** tackle these challenges,we propose the Convolution-based Efficient Transformer Image Feature Extraction Network(CEFormer)as an enhancement of the Transformer *** model incorporates E-Attention,depthwise separable convolution,and dilated convolution to introduce crucial inductive biases,such as translation invariance,locality,and scale invariance,into the Transformer ***,we implement a lightweight convolution module to process the input images,resulting in faster convergence and improved *** results in an efficient convolution combined Transformer image feature extraction *** results on the ImageNet1k Top-1 dataset demonstrate that the proposed network achieves better accuracy while maintaining high computational *** achieves up to 85.0%accuracy across various model sizes on image classification,outperforming various baseline *** integrated into the Mask Region-ConvolutionalNeuralNetwork(R-CNN)framework as a backbone network,CEFormer outperforms other models and achieves the highest mean Average Precision(mAP)*** research presents a significant advancement in Transformer-based image feature extraction,balancing performance and computational efficiency.

关键词： Transformer E-Attention depth convolution dilated convolution CEFormer

Enhanced thermoelectric performance enabled by compositing ZrO_(2.in n-type SiGe alloy with low thermal conductivity

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Rare Metals 2024年第3期43卷 1167-1176页

作者： Meng-Fei Wang Hua-Jun Lai Ji-Sheng Liang Jun-Liang Chen Wang-yang Ding Qi Zhou Ying Peng Cheng-Yan Liu lei Miao Guangxi Key Laboratory for Relativity Astrophysics State Key Laboratory of Featured Metal Materials and Life-Cycle Safety for Composite StructuresSchool of Physical Science and TechnologyGuangxi UniversityNanning530004China Guangxi Academy of sciences Nanning530007China Key Laboratory of information Material Engineering Research Center of Electronic Information Materials and DevicesGuilin University of Electronic TechnologyMinistry of EducationGuilin541004China Guangxi Key Laboratory of Precision Navigation Technology and Application School of Information and CommunicationGuilin University of Electronic TechnologyGuilin541004China

SiGe-based thermoelectric(TE)materials have gained increasing interests due to their low maintenance costs,environmental friendliness and long ***,the intrinsically high thermal conductivity of Si-based materials also results in poor TE *** this investigation,a zirconia(ZrO_(2.)composite strategy was applied to an n-type SiGe alloy,tremendously elevating its TE *** mechanical alloying and spark plasma sintering(SPS)processes,the ZrO_(2.induced the formation of nanopores in the SiGe matrix via phosphorus ***,such increase in porosity enhanced the phonon scattering and dramatically suppressed lattice thermal conductivity,from 2.83 to 1.59 W·m^(-1)·K^(-1)at 873 ***,reduced phosphorus doping led to an increase in Seebeck coefficients and a relatively minor decrease in electrical conductivity,The power factor didn't deteriorate significantly,either,as its maximum of~3.43 mW·m^(-1-)K^(-2.was achieved at 873 K with(Si_(0.8)Ge_(0.2.)_(0.097)P_(0.03)(ZrO_(2.)_(0.003).In short,a peak figure of merit(ZT)of~1.2. at 873 K and an average ZT~0.7 from 32. to 873 K were *** study demonstrates that the electrical and thermal transportation of SiGe material can be synergistically tuned by compositing ZrO_(2.,illustrating a novel strategy to optimize the TE properties of bulk materials.

关键词： Thermoelectric SiGe alloy ZrO2.composting P element adsorption nanopores

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A GTD model and state space approach based method for extracting the UWB scattering center of moving target

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science china({2. sciences) 2011年第1期54卷 182-196页

作者： WANG Jun,WEI ShaoMing,SUN JinPing & MAO ShiYi School of electronic and information {2.,Beihang university,Beijing 100191,china 1. School of electronic and information {2. Beihang University Beijing 100191 China

Movements of the scattering center on the condition of ultra-wideband(UWB)will impact the extraction of *** paper presents an approach for extracting the moving targets’UWB scattering center parameters based on the geometrical theory of diffraction(GTD)model and the state space approach. Firstly,the UWB GTD scattering model is transformed into state-space equations in order to estimate the range and range rate through the singular value ***,the type parameter in the whole bandwidth is indicated dimension-reducedly by orthonormalized basis and estimated by traversal algorithm and minimumnorm ***,the intensity of scattering center is worked out based on the least square *** paper provides the Cramer-rao bound(CRB)for parameter *** effectiveness of the approach is verified by computer *** approach can estimate range,range rate,reflection intensity and type parameter simultaneously in order to improve the track of scattering centers and the target identification.

关键词： scattering center extraction GTD model state space approach ultra-wideband Doppler processing

Nb_(2.O_(5) nanocrystals decorated graphene composites as anode materials for high-performance dual-ion batteries

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Nano Research 2024年第3期17卷 1535-1541页

作者： lei Wang Fei Huang Guoyin Zhu Zhihui Dai Jiangsu Collaborative Innovation Center of Biomedical Functional Materials Jiangsu Key Laboratory of Biofunctional MaterialsSchool of Chemistry and Materials ScienceNanjing Normal UniversityNanjing 210023China Institute of Advanced Materials and Flexible electronics(IAMFE) School of Chemistry and Materials ScienceNanjing University of Information Science&TechnologyNanjing 210044China School of Chemistry and Molecular engineering Nanjing Tech UniversityNanjing 211816China

Niobium oxide(Nb_(2.O_(5))is a promising material in photocatalytic,solar cell,electronic like electron field emitters,and especially lithium-ion batteries(LIBs)because of its adjustable morphologies,controllable crystal type,stable structure,and environmental ***,its low electrical conductivity lowers the rate performance and limits the practical applications in ***,we present a one-step solid-state synthesis of orthogonal Nb_(2.O_(5) nanocrystals/graphene composites(Nb_(2.O_(5)/G)as high-performance anode materials in *** from the nanoscale crystalline structure Nb_(2.O_(5) and highly-conductive graphene substrate,the as-prepared Nb_(2.O_(5)/G exhibits excellent electrochemical ***,a reversible structural phase transition between orthogonal Nb_(2.O_(5) and tetragonal Li1-xNbO_(2.(02.O_(5)/G||graphite dual-ion batteries(DIBs)full cell delivers good electrochemical performance in terms of cyclic performance and rate *** believe this work can provide a clear route towards developing advanced transition metal oxide/graphene composite anode and a comprehension of its electrochemical reaction mechanism.

关键词： niobium oxide graphene anode dual-ion batteries graphite intercalation

Parameter estimation for SAR moving target in complex image domain

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science china({2. sciences) 2010年第4期53卷 854-866页

作者： ZUO Yu, XU Jia*, PENG YingNing & XIA XiangGen department of electronic {2., Tsinghua university, Beijing 100084, china 1. department of electronic {2. Tsinghua University Beijing 100084 China

Based on the proposed parametric model of SAR ground moving target in the complex image domain, this paper derives the Cramer-rao bounds (CRB) for the unknown model parameters estimation and obtains the inherent limitations for the moving target motion estimation in the SAR complex image domain. Firstly, the relationships are analyzed among the estimation performance and the target’s scattering intensity, Doppler parameters, motion parameters, as well as the power spectra of the target and the clutter. Furthermore, the parameter estimation performance is compared in the signal domain and the complex image domain (CID) to draw some useful conclusions. Besides, the reduction resolution processing is proposed to improve the parameter estimation, and its performance improvement is also presented with analytic expressions. For the homogeneous background, it is shown that the accurate parameter estimation and azimuth location may be realized for SAR ground moving target in the complex image domain. Finally, some numerical experiments are provided to demonstrate the effectiveness of the proposed methods.

关键词： synthetic aperture radar (SAR) moving target complex image domain parameter estimation Cramer-rao bound (CRB) reduce resolution processing (RRP)

A Denoiser for Correlated Noise Channel Decoding: Gated-Neural Network

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china Communications 2024年第2期21卷 122-128页

作者： Xiao Li Ling Zhao Zhen Dai Yonggang lei School of electronic and information {2. Beihang UniversityBeijing 100191China Beijing Institute of Tracking and Telecommunications Technology BITTT

This letter proposes a sliced-gated-convolutional neural network with belief propagation(SGCNN-BP) architecture for decoding long codes under correlated noise. The basic idea of SGCNNBP is using Neural Networks(NN) to transform the correlated noise into white noise, setting up the optimal condition for a standard BP decoder that takes the output from the NN. A gate-controlled neuron is used to regulate information flow and an optional operation—slicing is adopted to reduce parameters and lower training complexity. Simulation results show that SGCNN-BP has much better performance(with the largest gap being 5dB improvement) than a single BP decoder and achieves a nearly 1dB improvement compared to Fully Convolutional Networks(FCN).

关键词： belief propagation channel decoding correlated noise neural network

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