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Integration of Electrical Properties and Polarization Loss Modulation on Atomic Fe–N‑RGO for Boosting Electromagnetic Wave Absorption

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Nano-Micro Letters 2025年第2期17卷 517-532页

作者： Kaili Zhang Yuefeng Yan Zhen Wang Guansheng Ma Dechang Jia Xiaoxiao Huang Yu Zhou State key laboratory of precision Welding&Joining of Materials and Structures Harbin Institute of TechnologyHarbin 150001People’s Republic of China School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001People’s Republic of China MIIT key laboratory of Advanced Structural‑Functional Integration Materials&Green Manufacturing technology Harbin Institute of TechnologyHarbin 150001People’s Republic of China

Developing effective strategies to regulate graphene’s conduction loss and polarization has become a key to expanding its application in the electromagnetic wave absorption(EMWA)*** on the unique energy band structure of graphene,regulating its bandgap and electrical properties by introducing heteroatoms is considered a feasible ***,metal-nitrogen doping reduced graphene oxide(M–N-RGO)was prepared by embedding a series of single metal atoms M–N_(4) sites(M=Mn,Fe,Co,Ni,Cu,Zn,Nb,Cd,and Sn)in RGO using an N-coordination atom-assisted *** composites had adjustable conductivity and polarization to optimize dielectric loss and impedance matching for efficient EMWA *** results showed that the minimum reflection loss(RL_(min))of Fe–N-RGO reaches−74.05 dB(2.0 mm)and the maximum effective absorption bandwidth(EAB_(max))is 7.05 GHz(1.89 mm)even with a low filler loading of only 1 wt%.Combined with X-ray absorption spectra(XAFS),atomic force microscopy,and density functional theory calculation analysis,the Fe–N_(4) can be used as the polarization center to increase dipole polarization,interface polarization and defect-induced polarization due to d-p orbital hybridization and structural ***,electron migration within the Fe further leads to conduction loss,thereby synergistically promoting energy *** study demonstrates the effectiveness of metal-nitrogen doping in regulating the graphene′s dielectric properties,which provides an important basis for further investigation of the loss mechanism.

关键词： Electromagnetic wave absorption Fe-N-RGO Dipole polarization Conduction loss Impedance matching

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Advances in Graphene‑Based Electrode for Triboelectric Nanogenerator

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Nano-Micro Letters 2025年第1期17卷 378-403页

作者： Bin Xie Yuanhui Guo Yun Chen Hao Zhang Jiawei Xiao Maoxiang Hou Huilong Liu Li Ma Xin Chen Chingping Wong State key laboratory of precision Electronic Manufacturing technology and Equipment Guangdong University of TechnologyGuangzhou 510006People’s Republic of China School of Electromechanical Engineering Guangdong University of TechnologyGuangzhou 510006People’s Republic of China School of Materials Science and Engineering Georgia Institute of TechnologyAtlantaGA 30332USA

With the continuous development of wearable electronics,wireless sensor networks and other micro-electronic devices,there is an increasingly urgent need for miniature,flexible and efficient nanopower generation *** nanogenerator(TENG)technology can convert small mechanical energy into electricity,which is expected to address this *** the core component of TENG,the choice of electrode materials significantly affects its *** metal electrode materials often suffer from problems such as durability,which limits the further application of ***,as a novel electrode material,shows excellent prospects for application in TENG owing to its unique structure and excellent electrical *** review systematically summarizes the recent research progress and application prospects of TENGs based on graphene *** precision processing methods of graphene electrodes are introduced,and the applications of graphene electrode-based TENGs in various scenarios as well as the enhancement of graphene electrodes for TENG performance are *** addition,the future development of graphene electrode-based TENGs is also prospectively discussed,aiming to promote the continuous advancement of graphene electrode-based TENGs.

关键词： Triboelectric nanogenerator precision processing Graphene electrode Self-powered sensor

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Global Calibration Method of Multi-sensor Vision System Using Skew Laser Lines

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Chinese Journal of Mechanical Engineering 2012年第2期25卷 405-410页

作者： LIU Qianzhe SUN Junhua LIU Zhen ZHANG Guangjun key laboratory of precision opto-mechatronics technology of Ministry of Education Beihang UniversityBeijing 100191China

Multi-sensor vision system plays an important role in the 3D measurement of large ***,due to the widely distribution of sensors,the problem of lacking common fields of view（FOV） arises frequently,which makes the global calibration of the vision system quite *** primary existing solution relies on large-scale surveying equipments,which is ponderous and inconvenient for field *** this paper,a global calibration method of multi-sensor vision system is proposed and *** proposed method utilizes pairs of skew laser lines,which are generated by a group of laser pointers,as the calibration *** pair of skew laser lines provides a unique coordinate system in space which can be reconstructed in certain vision sensor＇s coordinates by using a planar *** the geometries of sensors are computed under rigid transformation constrains by taking coordinates of each skew lines pair as the *** method is applied on both visual cameras with synthetic data and a real two-camera vision system;results show the validity and good *** prime contribution of this paper is taking skew laser lines as the global calibration objects,which makes the method simple and *** method need no expensive equipments and can be used in large-scale calibration.

关键词： multi-vision system global calibration non-overlapping cameras skew laser lines

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Radiation-induced attenuation self-compensating effect in super-fluorescent fiber source

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Chinese Physics B 2014年第9期23卷 266-270页

作者：杨远洪索鑫鑫杨巍 key laboratory on precision opto-mechatronics technology of Ministry of Education Beihang University National key laboratory on Inertial technology Beihang University

The compact super-fluorescent fiber source （SFS） output spectra variations at different pump currents and under different dose of gamma-ray radiation were measured and compared respectively. The radiation-induced attenuation （RIA） self-compensating effect in SFS based on photo-bleaching was found and the general mathematic model of SFS output spectra variations was made. The radiation-induced background attenuation （RIBA） at the pump wavelength was identified to be the main cause of the total output power and spectra variations and the variations can then be compensated by active control of the pump power to enhance the self-compensating effect. With closed-loop feedback control of pump current, double-pass backward （DPB） configuration and spectrum re-shaping technology, an SFS prototype was made and tested. The mean-wavelength stability of about 87.4 ppm and output power instability of less than 5% were achieved under up to 200 krad （Si） gamma-ray irradiation.

关键词： super-fluorescent fiber source Er-doped fiber radiation-induced attenuation mean wavelength stability

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Enhanced reconstruction of partially occluded objects with occlusion removal in synthetic aperture integral imaging

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Chinese Optics Letters 2011年第4期9卷 30-33页

作者：周志良袁艳相里斌王潜 Department of precision Machinery and precision Instrumentation University of Science and Technology of China key laboratory of precision opto-mechatronics technology Ministration of EducationBeihang University Academy of opto-Electronics Chinese Academy of Sciences

Synthetic aperture integral imaging provides the ability to reconstruct partially occluded objects from multi-view images. However, the reconstructed images suffer from degraded contrast due to the superimposition of foreground defocus blur. We propose an algorithm to remove foreground occlusions before reconstructing backgrounds. Occlusions are identified by estimating the color variance on elemental images and then deleting it in the final synthetic image. We demonstrate the superiority of our method by presenting experimental results as well as comparing our method with other approaches.

关键词： Synthetic apertures

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Dynamic characteristics of resonant gyroscopes study based on the Mathieu equation approximate solution

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Chinese Physics B 2012年第5期21卷 58-65页

作者：樊尚春李艳郭占社李晶庄海涵 School of Instrument Science&opto-electronics Engineering Beihang University key laboratory of precision opto-mechatronics Techonology of Ministry of Education key laboratory of Inertial Science and technology for National Defence

Dynamic characteristics of the resonant gyroscope are studied based on the Mathieu equation approximate solution in this *** Mathieu equation is used to analyze the parametric resonant characteristics and the approximate output of the resonant *** method of small parameter perturbation is used to analyze the approximate solution of the Mathieu *** theoretical analysis and the numerical simulations show that the approximate solution of the Mathieu equation is close to the dynamic output characteristics of the resonant *** experimental analysis shows that the theoretical curve and the experimental data processing results coincide perfectly,which means that the approximate solution of the Mathieu equation can present the dynamic output characteristic of the resonant *** theoretical approach and the experimental results of the Mathieu equation approximate solution are obtained,which provides a reference for the robust design of the resonant gyroscope.

关键词： resonant gyroscopes dynamic characteristics Mathieu equation approximate solution

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Pre-locate net for object detection in high-resolution images

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Chinese Journal of Aeronautics 2022年第10期35卷 313-325页

作者： Yunhao ZHANG Tingbing XU Zhenzhong WEI key laboratory of precision opto-mechatronics technology Ministry of Educationand the School of Instrumentation and Optoelectronic EngineeringBeihang UniversityBeijing 100083China

Small-object detection has long been a ***-megapixel cameras are used to solve this problem in ***,current detectors are inefficient for high-resolution *** this work,we propose a new module called Pre-Locate Net,which is a plug-and-play structure that can be combined with most popular *** inspire the use of classification ideas to obtain candidate regions in images,greatly reducing the amount of calculation,and thus achieving rapid detection in high-resolution ***-Locate Net mainly includes two parts,candidate region classification and behavior *** region classification is used to obtain a candidate region,and behavior classification is used to estimate the scale of an *** follow-up processing is adopted according to different scales to balance the variance of the network *** from the popular candidate region generation method,we abandon the idea of regression of a bounding box and adopt the concept of classification,so as to realize the prediction of a candidate region in the shallow *** build a high-resolution dataset of aircraft and landing gears covering complex scenes to verify the effectiveness of our *** to state-of-the-art detectors(e.g.,Guided Anchoring,Libra-RCNN,and FASF),our method achieves the best m AP of 94.5 on 1920×1080 images at 16.7 FPS.

关键词： Aircraft and landing gear detection Candidate region Convolutional neural network High resolution images Small object

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Application of camera calibrating model to space manipulator with multi-objective genetic algorithm

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Journal of Central South University 2016年第8期23卷 1937-1943页

作者：王中宇江文松王岩庆 key laboratory of precision opto-mechatronics technology of Ministry of Education (Beihang University) Beijing 100191 China Academy of opto-Electronics Chinese Academy of Sciences Beijing 100094 China

The multi-objective genetic algorithm(MOGA) is proposed to calibrate the non-linear camera model of a space manipulator to improve its locational accuracy. This algorithm can optimize the camera model by dynamic balancing its model weight and multi-parametric distributions to the required accuracy. A novel measuring instrument of space manipulator is designed to orbital simulative motion and locational accuracy test. The camera system of space manipulator, calibrated by MOGA algorithm, is used to locational accuracy test in this measuring instrument. The experimental result shows that the absolute errors are [0.07, 1.75] mm for MOGA calibrating model, [2.88, 5.95] mm for MN method, and [1.19, 4.83] mm for LM method. Besides, the composite errors both of LM method and MN method are approximately seven times higher that of MOGA calibrating model. It is suggested that the MOGA calibrating model is superior both to LM method and MN method.

关键词： space manipulator camera calibration multi-objective genetic algorithm orbital simulation and measurement

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SiamDLA: Dynamic Label Assignment for Siamese Visual Tracking

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Computers, Materials & Continua 2023年第4期75卷 1621-1640页

作者： Yannan Cai Ke Tan Zhenzhong Wei key laboratory of precision opto-mechatronics technology Ministry of EducationSchool of Instrumentation Science and Opto-Electronics EngineeringBeihang UniversityBeijing100191China

Label assignment refers to determining positive/negative labels foreach sample to supervise the training process. Existing Siamese-based trackersprimarily use fixed label assignment strategies according to human priorknowledge;thus, they can be sensitive to predefined hyperparameters and failto fit the spatial and scale variations of samples. In this study, we first developa novel dynamic label assignment (DLA) module to handle the diverse datadistributions and adaptively distinguish the foreground from the backgroundbased on the statistical characteristics of the target in visual object *** core of DLA module is a two-step selection mechanism. The first stepselects candidate samples according to the Euclidean distance between trainingsamples and ground truth, and the second step selects positive/negativesamples based on the mean and standard deviation of candidate *** proposed approach is general-purpose and can be easily integrated intoanchor-based and anchor-free trackers for optimal sample-label *** to extensive experimental findings, Siamese-based trackers withDLA modules can refine target locations and outperformbaseline trackers onOTB100, VOT2019, UAV123 and LaSOT. Particularly, DLA-SiamRPN++improves SiamRPN++ by 1% AUC and DLA-SiamCAR improves Siam-CAR by 2.5% AUC on OTB100. Furthermore, hyper-parameters analysisexperiments show that DLA module hardly increases spatio-temporal complexity,the proposed approach maintains the same speed as the originaltracker without additional overhead.

关键词： Siamese network label assignment single object tracking anchorbased anchor-free

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Weighted Marginal Fisher Analysis with Spatially Smooth for aircraft recognition

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Chinese Journal of Aeronautics 2014年第1期27卷 110-116页

作者： Wei Zhenzhong Liu Chang Li Nan precision opto-mechatrionics technology Key Laboratory of Education MinistryBeihang University

Due to limitations to extract invariant features for recognition when the aircraft presents various poses and lacks enough samples for training, a novel algorithm called Weighted Marginal Fisher Analysis with Spatially Smooth （WMFA-SS） for extracting invariant features in aircraft rec- ognition is proposed. According to the Graph Embedding （GE） framework, Heat Kernel function is firstly introduced to characterize the interclass separability when choosing the weights of penalty graph. Furthermore, Laplacian penalty is applied to constraining the coefficients to be spatially smooth in this algorithm. Laplacian penalty is able to incorporate the prior information that neigh- boring pixels are correlated. Besides, using a Laplacian penalty can also avoid the singularity of Laplacian matrix of intrinsic graph. Once compact representations of the images are obtained, it can be considered as invariant features and then be performed in classification to recognize different patterns of aircraft. Real aircraft recognition experiments show the superiority of our proposed WMFA-SS in comparison to other GE algorithms and the current aircraft recognition algorithm; the accuracy rate of our proposed method is 90.00% for dataset BH-AIR1.0 and 99.25% for dataset BH-AIR2.0.

关键词： Aircraft dataset Aircraft recognition Graph Embedding Invariant feature Laplacian operator Subspace learning

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