2024
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Record 97 of
Title:A Snapshot Multi-Spectral Demosaicing Method for Multi-Spectral Filter Array Images Based on Channel Attention Network
Author Full Names:Zhang, Xuejun(1,2); Dai, Yidan(1,2); Zhang, Geng(1); Zhang, Xuemin(3); Hu, Bingliang(1)Source Title:SensorsLanguage:EnglishDocument Type:Journal article (JA)Abstract:Multi-spectral imaging technologies have made great progress in the past few decades. The development of snapshot cameras equipped with a specific multi-spectral filter array (MSFA) allow dynamic scenes to be captured on a miniaturized platform across multiple spectral bands, opening up extensive applications in quantitative and visualized analysis. However, a snapshot camera based on MSFA captures a single band per pixel; thus, the other spectral band components of pixels are all missed. The raw images, which are captured by snapshot multi-spectral imaging systems, require a reconstruction procedure called demosaicing to estimate a fully defined multi-spectral image (MSI). With increasing spectral bands, the challenge of demosaicing becomes more difficult. Furthermore, the existing demosaicing methods will produce adverse artifacts and aliasing because of the adverse effects of spatial interpolation and the inadequacy of the number of layers in the network structure. In this paper, a novel multi-spectral demosaicing method based on a deep convolution neural network (CNN) is proposed for the reconstruction of full-resolution multi-spectral images from raw MSFA-based spectral mosaic images. The CNN is integrated with the channel attention mechanism to protect important channel features. We verify the merits of the proposed method using 5 × 5 raw mosaic images on synthetic as well as real-world data. The experimental results show that the proposed method outperforms the existing demosaicing methods in terms of spatial details and spectral fidelity. ? 2024 by the authors.Affiliations:(1) Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an; 710119, China; (2) University of Chinese Academy of Sciences, Beijing; 100049, China; (3) Institute of Aerospace Science and Technology, School of Remote Sensing and Information Engineering, Wuhan University, Wuhan; 430072, ChinaPublication Year:2024Volume:24Issue:3Article Number:943DOI Link:10.3390/s24030943數(shù)據(jù)庫ID（收錄號）:20240715548327 -
Record 98 of
Title:Material removal and surface generation mechanisms in rotary ultrasonic vibration–assisted aspheric grinding of glass ceramics
Author Full Names:Sun, Guoyan(1,2); Wang, Sheng(3); Zhao, Qingliang(3); Ji, Xiabin(1); Ding, Jiaoteng(1)Source Title:International Journal of Advanced Manufacturing TechnologyLanguage:EnglishDocument Type:Journal article (JA)Abstract:High-efficiency precision grinding can shorten the machining cycle of aspheric optical elements by a factor of 2–10. To achieve this objective, ultrasonic vibration (UV)–assisted grinding (UVG) has been increasingly applied to manufacture aspheric optics. However, the mechanisms of material removal and surface formation in UV-assisted aspheric grinding of glass ceramics have rarely been studied. Herein, rotary UV-assisted vertical grinding (RUVG) was used to explore the machining mechanism of coaxial curved surfaces. First, RUV-assisted scratch experiments were conducted on aspheric surface of glass ceramics, which exhibited multiple benefits over conventional scratching. These include a reduction in the scratch force by 37.83–44.55% for tangential component and 3.87–28.15% for normal component, an increase in plastic removal length by 43.75%, and an increase in material removal rate by almost a factor of 2. Moreover, grinding marks on the aspheric surface in RUVG were accurately simulated and optimized by adjusting grinding parameters. RUVG experiments were performed to verify the accuracy of grinding texture simulations and investigate the UV effect. The results demonstrate that UV can improve the surface quality of aspheric grinding when compared with conventional vertical grinding. In particular, the total height of the profile of form accuracy and its root mean square were significantly improved by a factor of 3.38–4.54 and 7.15–10.82, respectively, and the surface roughness reduced by 10.03–12.10%. This study provides deeper insight into material removal and surface generation mechanisms for RUVG of aspheric surfaces, and it is thus envisaged that these results will be useful in engineering applications. ? 2024, The Author(s), under exclusive licence to Springer-Verlag London Ltd., part of Springer Nature.Affiliations:(1) Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an; 710119, China; (2) College of Artificial Intelligence, National University of Defense Technology, Changsha; 410003, China; (3) Center for Precision Engineering School of Mechatronics Engineering, Harbin Institute of Technology, Harbin; 150001, ChinaPublication Year:2024Volume:130Issue:7-8Start Page:3721-3740DOI Link:10.1007/s00170-023-12904-x數(shù)據(jù)庫ID（收錄號）:20240215352394 -
Record 99 of
Title:Fatigue mechanism analysis and life prediction model of piezoelectric ceramic tube based on fiber-optic nutator
Author Full Names:Peng, Bo(1,2,3); Ruan, Ping(1,3); Han, Junfeng(1,3); Chang, Zhiyuan(1,3); Han, Jingyu(1,2,3); Wang, Jiahao(1,2,3); He, Deqiu(1,2,3)Source Title:Proceedings of SPIE - The International Society for Optical EngineeringLanguage:EnglishDocument Type:Conference article (CA)Conference Title:5th International Conference on Optoelectronic Science and Materials, ICOSM 2023Conference Date:September 22, 2023 - September 24, 2023Conference Location:Hefei, ChinaConference Sponsor:Academic Exchange Information Centre (AEIC)Abstract:As a driving unit and core component of the acquisition, pointing and tracking (APT) system's fiber actuator, the fatigue mechanism and fatigue life analysis of the piezoelectric ceramic tube (PCT) nutator in a high-frequency dynamic state have become one of the urgent research issues in the reliability field of interstellar laser communicating key devices. This article commences by elucidating the principles of deflection and nutation of the PCT nutator. Subsequently, employing finite element simulation methodologies, an exhaustive analysis is conducted to discern the stress and strain energy density distribution within a single operational cycle under specific working parameters. The findings illuminate the principal fatigue failure mechanism of the dynamic piezoelectric ceramic tube, characterized by crack propagation and eventual rupture resulting from localized stress accumulation during dynamic processes. Furthermore, the coordinates of the "most dangerous element" are ascertained, and a fatigue life model for the PCT nutator in transient nutation is proposed based on the theory of material fatigue damage accumulation. Based on model calculations, the theoretical fatigue life of the PCT nutator can reach 2.31×106 cycles under the environmental conditions with a 500Hz bandwidth and maximum nutation radius. ? 2024 SPIE.Affiliations:(1) Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an; 710119, China; (2) University of Chinese Academy of Sciences, Beijing; 100049, China; (3) Key Laboratory of Space Precision Measurement Technology, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an; 710119, ChinaPublication Year:2024Volume:13068Article Number:130680ODOI Link:10.1117/12.3016249數(shù)據(jù)庫ID（收錄號）:20240715542577 -
Record 100 of
Title:Parameter-free super-resolution structured illumination microscopy via a physics-enhanced neural network
Author Full Names:Wang, Siying(1,2); Bai, Chen(1,2); Li, Xing(1,2); Qian, Jia(1); Li, Runze(1); Peng, Tong(1); Tian, Xuan(1,2); Ma, Wang(1,2); Ma, Rui(1,2); An, Sha(3); Gao, Peng(3); Dan, Dan(1,2); Yao, Baoli(1,2)Source Title:Optics LettersLanguage:EnglishDocument Type:Journal article (JA)Abstract:With full-field imaging and high photon efficiency advantages, structured illumination microscopy (SIM) is one of the most potent super-resolution (SR) modalities in bioscience. Regarding SR reconstruction for SIM, spatial domain reconstruction (SDR) has been proven to be faster than traditional frequency domain reconstruction (FDR), facilitating real-time imaging of live cells. Nevertheless, SDR relies on high-precision parameter estimation for reconstruction, which tends to suffer from low signal-to-noise ratio (SNR) conditions and inevitably leads to artifacts that seriously affect the accuracy of SR reconstruction. In this Letter, a physics-enhanced neural network-based parameter-free SDR (PNNP-SDR) is proposed, which can achieve SR reconstruction directly in the spatial domain. As a result, the peak-SNR (PSNR) of PNNP-SDR is improved by about 4 dB compared to the cross-correlation (COR) SR reconstruction; meanwhile, the reconstruction speed of PNNP-SDR is even about five times faster than the fast approach based on principal component analysis (PCA). Given its capability of achieving parameter-free imaging, noise robustness, and high-fidelity and high-speed SR reconstruction over conventional SIM microscope hardware, the proposed PNNP-SDR is expected to be widely adopted in biomedical SR imaging scenarios. ? 2024 Optica Publishing Group. All rightsAffiliations:(1) State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an; 710119, China; (2) University of Chinese Academy of Sciences, Beijing; 100049, China; (3) School of Physics, Xidian University, Xi’an; 710071, ChinaPublication Year:2024Volume:49Issue:17Start Page:4855-4858DOI Link:10.1364/OL.533164數(shù)據(jù)庫ID（收錄號）:20243516948264 -
Record 101 of
Title:Modeling and Analysis of Electromechanical Automatic Leveling Mechanism for High-Mobility Vehicle-Mounted Theodolites
Author Full Names:Li, Xiangyu(1,2,3); Ruan, Ping(1,2); Hao, Wei(1,2); Xie, Meilin(1,2); Lv, Tao(1,2,3)Source Title:IEICE Transactions on Fundamentals of Electronics, Communications and Computer SciencesLanguage:EnglishDocument Type:Journal article (JA)Abstract:To achieve precise measurement without landing, the high-mobility vehicle-mounted theodolite needs to be leveled quickly with high precision and ensure sufficient support stability before work. After the measurement, it is also necessary to ensure that the high-mobility vehicle-mounted theodolite can be quickly withdrawn. Therefore, this paper proposes a hierarchical automatic leveling strategy and establishes a two-stage electromechanical automatic leveling mechanism model. Using coarse leveling of the first-stage automatic leveling mechanism and fine leveling of the second-stage automatic leveling mechanism, the model realizes high-precision and fast leveling of the vehicle-mounted theodolites. Then, the leveling control method based on repeated positioning is proposed for the first-stage automatic leveling mechanism. To realize the rapid withdrawal for high-mobility vehicle-mounted theodolites, the method ensures the coincidence of spatial movement paths when the structural parts are unfolded and withdrawn. Next, the leg static balance equation is constructed in the leveling state, and the support force detection method is discussed in realizing the stable support for vehicle-mounted theodolites. Furthermore, a mathematical model for "false leg" detection is established furtherly, and a "false leg" detection scheme based on the support force detection method is analyzed to significantly improve the support stability of vehicle-mounted theodolites. Finally, an experimental platform is constructed to perform the performance test for automatic leveling mechanisms. The experimental results show that the leveling accuracy of established two-stage electromechanical automatic leveling mechanism can reach 3.600, and the leveling time is no more than 2 mins. The maximum support force error of the support force detection method is less than 15%, and the average support force error is less than 10%. In contrast, the maximum support force error of the drive motor torque detection method reaches 80.12%, and its leg support stability is much less than the support force detection method. The model and analysis method proposed in this paper can also be used for vehicle-mounted radar, vehicle-mounted laser measurement devices, vehicle-mounted artillery launchers and other types of vehicle-mounted equipment with high-precision and high-mobility working requirements. ? 2024 The Institute of Electronics, Information and Communication Engineers.Affiliations:(1) Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an; 710119, China; (2) Key Laboratory of Space Precision Measurement Technology, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an; 710119, China; (3) University of Chinese Academy of Sciences, Beijing; 100049, ChinaPublication Year:2024Volume:E107.AIssue:7Start Page:1027-1039DOI Link:10.1587/transfun.2023EAP1058數(shù)據(jù)庫ID（收錄號）:20242716644921 -
Record 102 of
Title:Enhancement and suppression of nonsequential double ionization by spatially inhomogeneous fields
Author Full Names:Luo, Xuan(1); Jiao, Li Guang(2); Liu, Aihua(1,3); Liu, Xueshen(1)Source Title:Optics ExpressLanguage:EnglishDocument Type:Journal article (JA)Abstract:Using the three-dimensional classical ensemble approach, we theoretically investigate the nonsequential double ionization of argon atoms in an intense laser field enhanced by bowtienanotip. We observe an anomalous decrease in the double ionization yield as the laser intensity increases, along with a significant gap in the low momentum of photoelectrons. According to our theoretical analysis, the finite range of the induced field by the nanostructure is the fundamental cause of the decline in double ionization yield. Driven by the enhanced inhomogeneous field, energetic electrons can escape from the finite range of nanotips without returning. This reduces the possibility of re-scattering on the nucleus and imprints the finite size effect into the double ionization yield and momentum distribution of photoelectrons in the form of yield decline and a gap in the photoelectron-momentum distribution. ? 2024 Optica Publishing Group.Affiliations:(1) Institute of Atomic and Molecular Physics, Jilin University, Changchun; 130012, China; (2) College of Physics, Jilin University, Changchun; 130012, China; (3) State Key Laboratory of Transient Optics and Photonics, Chinese Academy of Sciences, Xi'an; 710119, ChinaPublication Year:2024Volume:32Issue:11Start Page:19825-19836DOI Link:10.1364/OE.523593數(shù)據(jù)庫ID（收錄號）:20242216154618 -
Record 103 of
Title:Linear-space-variant model for Fourier ptychographic microscopy
Author Full Names:Feng, Tianci(1,2); Wang, Aiye(1,2); Wang, Zhiping(1,3); Liao, Yizheng(1,2); Pan, An(1,2)Source Title:Optics LettersLanguage:EnglishDocument Type:Journal article (JA)Abstract:Fourier ptychographic microscopy (FPM) needs to realize well-accepted reconstruction by image segmentation and discarding problematic data due to artifacts caused by vignetting. However, the imaging results have long suffered from uneven color blocks and the consequent digital stitching artifacts, failing to bring satisfying experiences to researchers and users over the past decade since the invention of FPM. In fact, the fundamental reason for vignetting artifacts lies in that the acquired data does not match the adopted linear-space-invariant (LSI) forward model, i.e., the actual object function is modulated by a quadratic phase factor during data acquisition, which has been neglected in the advancement of FPM. In this Letter, we rederive a linear-space-variant (LSV) model for FPM and design the corresponding loss function for FPM, termed LSV-FPM. Utilizing LSV-FPM for optimization enables the efficient removal of wrinkle artifacts caused by vignetting in the reconstruction results, without the need of segmenting or discarding images. The effectiveness of LSV-FPM is validated through data acquired in both 4f and finite conjugate single-lens systems. ? 2024 Optica Publishing Group (formerly OSA). All rights reserved.Affiliations:(1) State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an; 710119, China; (2) University of Chinese Academy of Sciences, Beijing; 100049, China; (3) School of Physical Science and Technology, Lanzhou University, Gansu, Lanzhou; 730000, ChinaPublication Year:2024Volume:49Issue:10Start Page:2617-2620DOI Link:10.1364/OL.522745數(shù)據(jù)庫ID（收錄號）:20242116112682 -
Record 104 of
Title:Calibration method of relative spectral response function of indirect imaging spectrometer
Author Full Names:Li, Xiao-Xiao(1,2); Li, Juan(1); Bai, Cai-Xun(3); Chang, Chen-Guang(1,2); Hao, Xiong-Bo(1); Wen, Zhen-Qing(1,2); Wang, Peng-Chong(1); Feng, Yu-Tao(1)Source Title:Wuli Xuebao/Acta Physica SinicaLanguage:ChineseDocument Type:Journal article (JA)Abstract:In imaging spectrometers, area array detectors are usually used as photoelectric conversion devices, but the inconsistency of the spectral response among pixels can distort the collected target spectra. To improve the spectral radiometric accuracy of imaging spectrometers, calibrating and correcting the inconsistency of the spectral response among pixels is essential. The signal received by each pixel of area array detector of the indirect imaging spectrometer is usually the superposition of the target multi-spectral radiation signals or full-spectral radiation signals. Therefore, its relative spectral radiometric calibration requires measuring the spectral response of each pixel at different wavelengths on the array detector. Under the ideal conditions, the response values of each pixel in the area array detector are different, so the indirect imaging spectrometer cannot simply calibrate the relative spectral response (RSR) function between pixels by using the method of "monochromator + integrating sphere". In this work, taking the interferometric imaging spectrometer for example, we analyze the influence of the inconsistency of the RSR among pixels on the target spectral radiation measurement accuracy, and propose a system-level RSR function measurement method for the indirect imaging spectrometer based on the Fourier transform modulation calibration source. In addition, we establish a mathematical model for calibrating the RSR function,and provide guidelines for selecting calibration system parameters such as light source, spectral resolution, and OPD sampling interval. The simulation results show that under the ideal noise-free condition, the 1% spectral response inconsistency among pixels results in a relative error of 1.02% to the recovered spectra. After RSR correction, the relative error of the recovered spectra of different rows decreases to 0.08%. Furthermore, in this work we simulate and analyse the influence of spectral signal-to-noise ratio on the calibration accuracy of the RSR function, and point out that increasing the brightness of the calibration light source, extending exposure time, and combining multi-frame interferograms can enhance RSR function calibration accuracy in practical applications. The research result can provide a theoretical basis for realizing the relative spectral radiometric calibration of indirect imaging spectrometer, which is of great significance in promoting quantitative spectral remote sensing. ? 2024 Chinese Physical Society.Affiliations:(1) Key Laboratory of Spectral Imaging Technology, Xi’an Institute of Optics Precision Mechanic, Chinese Academy of Sciences, Xi’an; 710119, China; (2) University of Chinese Academy of Sciences, Beijing; 100049, China; (3) School of Physics and Optoelectronic Engineering, Shandong University of Technology, Zibo; 255000, ChinaPublication Year:2024Volume:73Issue:12Article Number:120703DOI Link:10.7498/aps.73.20240200數(shù)據(jù)庫ID（收錄號）:20242616443379 -
Record 105 of
Title:Hyperspectral scene classification dataset based on Zhuhai-1 images
Author Full Names:Liu, Yuan(1,2); Zheng, Xiangtao(3); Lu, Xiaoqiang(3)Source Title:National Remote Sensing BulletinLanguage:ChineseDocument Type:Journal article (JA)Abstract:Hyperspectral remote sensing is a key technology for remotely obtaining the physical parameters of ground objects and realizing fine identification. It can not only get geometrical properties of the target scenes but also obtain radiance that reflects the characteristics of ground objects. With the development of hyperspectral remote sensing data to unprecedented spatial, spectral, temporal resolution and large data volume, how to adapt to the requirements of massive data and achieve efficient and rapid processing of hyperspectral remote sensing data has become the current research focus. Researchers are introducing scene classification into hyperspectral image classification, integrating the spatial and spectral information to obtain semantic information oriented to larger observation units. However, almost all existing multispectral/hyperspectral scene classification datasets have a number of limitations, including inconsistent spectral and spatial resolutions or spatial resolutions too large to meet the needs of fine-grained classification. Based on the hyperspectral images of Xi’an taken by the "Zhuhai-1" constellation, we combine the result of unsupervised spectral clustering and Google Earth to establish a hyperspectral satellite image scene classification dataset named HSCD-ZH (Hyperspectral Scene Classification Dataset from Zhuhai-1). It consists of 737 images divided into six categories: urban, agriculture, rural, forest, water, and unused land. Each image with a size of 64 × 64 pixels consists of 32 bands covering the wavelength in the range of 400—1000 nm. In addition, we conduct spatial-based and spectral-based experiments to analyze the performance of existing datasets, and the benchmark results are reported as a valuable baseline for subsequent research. We choose false-color image for the spatial-based experiments and then use popular deep and non-deep learning scene classification techniques. In the experiments based on spectral, the spectral vectors at the pixel are directly used as local spectral features, and BoVW, IFK, and LLC are used to encode them to generate global representations for the scene. Using SVM as the classifier, the optimal overall classification achieved by the two experiments on the proposed dataset is 92.34% and 88.96%, respectively. Considering that those methods have a large amount of information loss, we cascade the features extracted by the two approaches to generate spatial-spectral features. The highest overall accuracy obtained reaches 94.64%, which is the highest improvement in overall accuracy compared to the other datasets. We construct HSCD-ZH by effectively exploiting both spectral and spatial features of hyperspectral images, selecting various scenes that either have representative spectral compositions, clear spatial textures, or both. It has the advantages of big intraclass diversity, strong scalability, and adapting to satellite hyperspectral intelligent information extraction requirements. Both dataset and experiments can provide effective data support for remote sensing scene classification research in the hyperspectral field. Meanwhile, experiments can indicate that extracting features based on spatial or spectral misses a large amount of available information, and integrating the features extracted by the two methods can compensate for this deficiency. In our future work, we aim to expand the number of categories and images of HSCD-ZH and continue to explore algorithms for integrating spatial and spectral information that can accelerate the interpretation and efficient exploitation of hyperspectral scene cubes. ? 2024 Science Press. All rights reserved.Affiliations:(1) Key Laboratory of Spectral Imaging Technology, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an; 710119, China; (2) University of Chinese Academy of Sciences, Beijing; 100049, China; (3) College of Physics and Information Engineering, Fuzhou University, Fuzhou; 350108, ChinaPublication Year:2024Volume:28Issue:1Start Page:306-319DOI Link:10.11834/jrs.20233283數(shù)據(jù)庫ID（收錄號）:20241515892427 -
Record 106 of
Title:Co-axial superposition: generation of perfect vortex beams with multi-openings and adjustable spherical symmetry
Author Full Names:Hussain, Anwar(1,2); Zhou, Meiling(1); Zhou, Yuan(1); Li, Runze(1); Peng, Tong(1); Yan, Shaohui(1); Min, Junwei(1); Dan, Dan(1); Yao, Baoli(1,3)Source Title:Journal of the Optical Society of America A: Optics and Image Science, and VisionLanguage:EnglishDocument Type:Journal article (JA)Abstract:The perfect vortex beam, with a diameter that remains independent of the topological charge, has numerous applications in far-field information propagation. In this study, a hologram is obtained through the co-spiral superposition of two primary spiral axicons which is assigned to spatial light modulator for the generation of perfect vortex beams. Key parameters such as the topological charge and intra-ring spacing of individual spiral axicons play critical roles in controlling the characteristics of the resulting perfect vortex beam through the resultant hologram. By adjusting these parameters, precise control can be exerted over the number of openings in the beam and the diameter of the central dark area of the beam. The generation of the entire family of vortex beams with both odd and even numbers of openings in both symmetrical and asymmetrical geometry of the vortex beam petals is presented in simulation and experiment. The perfect vortex beam reported here is characterized by its adjustable number of openings and controllable petal size, holding significant potential for applications in optical trapping. The existence of multiple circular vortex petals with different radii is expected to enable the optical sorting of different particles. ? 2024 Optica Publishing Group. All rights,Affiliations:(1) State Key Laboratory of Transient Optics and Photonics, Xi‘a(chǎn)n Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi’an; 710119, China; (2) COMSATS University Islamabad (CUI), Park Road, Tarlai Kalan, Islamabad; 45550, Pakistan; (3) University of Chinese Academy of Sciences, Beijing; 100049, ChinaPublication Year:2024Volume:41Issue:11Start Page:2149-2155DOI Link:10.1364/JOSAA.537676數(shù)據(jù)庫ID（收錄號）:20244717405541 -
Record 107 of
Title:Regulable Crack Patterns for the Fabrication of High-Performance Transparent EMI Shielding Windows
Author Full Names:Guan, Yongmao(1,2); Yang, Liqing(1); Chen, Chao(1); Wan, Rui(1); Guo, Chen(1,2); Wang, Pengfei(1,2)Source Title:SSRNLanguage:EnglishDocument Type:Preprint (PP)Abstract:Crack pattern based metal grid film is an ideal candidate material for transparent electromagnetic interference shielding optical windows. However, achieving crack patterns with narrow grid spacing, small wire width and high connectivity remains challenging. Herein, an aqueous acrylic colloidal dispersion was developed as a crack precursor for preparing crack patterns. The ratio of hard monomers in the precursor, the coating thickness, and the drying mediation strategy were systematically varied to control the spacing and width of the crack patterns. The resulting dense and narrow crack patterns served as sacrificial templates for the fabrication of patterning metal grid films on transparent substrates, intended for optoelectronic applications. These films demonstrated high UV-Vis-IR transmittance (~81.8%) in the wavelength range of 200-800 nm and 1.5-4 μm and strong EMI shielding effectiveness (~33.6 dB) in the microwave frequency range of 1-18 GHz, showcasing their potential as a scalable and effective transparent EMI shielding solution. ? 2024, The Authors. All rights reserved.Affiliations:(1) State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences (CAS), Shaanxi, Xi’an; 710119, China; (2) Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing; 100049, ChinaPublication Year:2024數(shù)據(jù)庫ID（收錄號）:20240345916 -
Record 108 of
Title:Surface degradation of epoxy resin exposed to corona discharge under bipolar square wave field: From phenomenon to the insights
Author Full Names:Zhang, Chuang(1); Xiang, Jiao(2); Chen, Zhen(3); Wang, Zhuofei(4); Su, Yiling(1); Wang, Shihang(1); Li, Jianying(1); Li, Shengtao(1)Source Title:Polymer Degradation and StabilityLanguage:EnglishDocument Type:Journal article (JA)Abstract:The unavoidable corona discharge induced by distorted field is detrimental to the safety of power equipment, especially the equipment with high voltage magnitude and high frequency. In this paper, the degradation morphology, residual components, lifetime of endurance, partial discharge characteristics, and evolution of surface traps of epoxy insulation under bipolar square wave field is investigated. The results show that degraded zone exhibits as three layers with round pits and channel-like ravines on the surface of epoxy resin exposed to corona discharge. It is demonstrated that more oxygen element during corona discharge while more carbon element during breakdown appeared, and nano-Al2O3 fillers migrates to the discharged zone. The maximum temperature and number of emitted phonons increase with voltage amplitude and frequency in power law and exponential form, respectively, corresponding to the fitting function of endurance lifetime. The emitted light is concentrated on the near ultraviolet (UV) and infrared ray (IR) band, indicating the energy pooling and thermal effect of corona discharge, which interprets the distinct degradation behavior of samples under sinusoidal and bipolar square wave voltage. The effect of space charge and thermal conductivity should be considered simultaneously in the degradation of epoxy insulation under bipolar square wave field due to polarity reversal and high frequency, which is proved by the disparate behavior of EP/nano-Al2O3 composites resistance to corona discharge and the breakdown moment at falling edge of bipolar square wave voltage. This work may contribute to the advancement of resistance to corona discharge degradation in equipment with high power density, high voltage amplitude and high frequency. ? 2024Affiliations:(1) State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong University, Shaanxi, Xi'an; 710049, China; (2) Power China Hubei Electric Engineering Co., Ltd., Hubei, Wuhan; 430000, China; (3) Xi 'an Institute of Optics and Precision Mechanics of CAS, Shaanxi, Xi'an; 710049, China; (4) University of Chinese Academy of Sciences, Beijing; 100049, ChinaPublication Year:2024Volume:228Article Number:110922DOI Link:10.1016/j.polymdegradstab.2024.110922數(shù)據(jù)庫ID（收錄號）:20243016735840