2024

• Record 1 of
  
  Title:Research on subsurface damage mechanism and suppression method of ultrasonic vibration–assisted grinding of sapphire components under extreme service environment
  
  Author(s):Sun, GuoYan(2); Zhang, Wanli(1,4,5); Wang, JianYong(3); Ding, JiaoTeng(2); Wang, Bo(1,4,5); Shi, Feng(1,4,5)
  Source:International Journal of Advanced Manufacturing Technology
  Volume:   Issue:   DOI: 10.1007/s00170-024-14491-x  Published: 2024  
  Abstract:Single-crystal sapphire (α-Al2O3) has a wide range of applications in a variety of extreme environments due to its excellent mechanical and chemical properties as well as its stability under extreme service conditions. In addition, sapphire is a hard and brittle material, which makes it difficult to avoid the introduction of subsurface damage during processing, and the existence of a subsurface damage layer seriously affects the performance of the optical system. Therefore, this study focuses on the mechanism of subsurface damage in sapphire grinding, the suppression of damage depth, and the accurate and fast prediction of damage depth. A subsurface damage model for ultrasonic vibration–assisted grinding of sapphire was established by combining ultrasonic vibration single abrasive grain kinematics and dynamics analysis. The mechanism of ultrasonic vibration–assisted grinding was investigated by combining force and acoustic emission (AE) signals. And the effects of ultrasonic vibration–assisted grinding on the surface quality, subsurface damage form, and depth were analyzed. A comprehensive prediction model of SSD based on surface roughness (Sz) was established by combining indentation fracture mechanics and Gaussian process regression. Finally, by analyzing the influence law of each process parameter on the subsurface damage depth (SSD), the grinding process parameters were optimized, and the subsurface damage suppression strategy was proposed. This study provides theoretical guidance for the high-efficiency and low-damage grinding of sapphire. © The Author(s), under exclusive licence to Springer-Verlag London Ltd., part of Springer Nature 2024.
  Accession Number: 20244317254246
• Record 2 of
  
  Title:Interactive Enhanced Network Based on Multihead Self-Attention and Graph Convolution for Classification of Hyperspectral and LiDAR Data
  
  Author(s):Gao, Hongmin(2); Feng, Hao(1); Zhang, Yiyan(1); Fei, Shuyu(1); Sheng, Runhua(2); Xu, Shufang(2,3); Zhang, Bing(4)
  Source:IEEE Transactions on Geoscience and Remote Sensing
  Volume:   Issue:   DOI: 10.1109/TGRS.2024.3467674  Published: 2024  
  Abstract:The fusion of multimodal data plays a crucial role in classification tasks. However, existing research typically mines and analyzes the individual features of each data source separately before considering how to fuse them. In contrast, our approach first constructs interactive enhanced fusion features for initial fusion while considering the extraction of individual features, and finally integrates them effectively to utilize the information from each data source more comprehensively. To this end, we propose a novel interactive enhanced network based on multihead self-attention (MSA) and graph convolution. Specifically, we extract individual features from hyperspectral image (HSI) and light detection and ranging (LiDAR) data, and then construct interactive enhanced fusion features based on the row and column features of the central pixel. Individual features focus on the local characteristics of a single data source, while interactive enhanced fusion features strengthen the feature expression of the central pixel through matrix operations, integrating the complementary information of multimodal data. Subsequently, we use graph convolutional networks to construct graph structures for four types of features (interactive enhanced HSI features, interactive enhanced LiDAR features, HSI individual features, and LiDAR individual features), modeling the pixels as nodes and capturing spatial relationships. On this basis, we apply an MSA mechanism to mine spectral dependencies, further extracting global spectral features. Finally, we design a multimodal gated fusion module that effectively integrates these features through its weighting mechanism. The weight allocation is adjusted dynamically according to the characteristics of the feature, achieving optimal fusion of multimodal data. Extensive experiments on three popular HSI and LiDAR datasets verify the superior performance of our method. Our code will be available at https://github.com/haofeng0003/MSA-GCN. © 2024 IEEE.
  Accession Number: 20244017121067
• Record 3 of
  
  Title:Location-Guided Dense Nested Attention Network for Infrared Small Target Detection
  
  Author(s):Guo, Huinan(1,2); Zhang, Nengshuang(3); Zhang, Jing(3); Zhang, Wuxia(4); Sun, Congying(3)
  Source:IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
  Volume:   Issue:   DOI: 10.1109/JSTARS.2024.3472041  Published: 2024  
  Abstract:Infrared Small Target (IST) detection involves identifying objects that occupy fewer than 81pixels in a 256×256 image. Because the target is small and lacks texture, structure, and shape information on its surface, this task is highly challenging. CNN-based methods can extract rich features of the target. However, overly deep network structures may increase the risk of losing small targets. Additionally, pixel-level positional deviations can also reduce the detection accuracy of IST. To address these challenges, we propose the Location-Guided Dense Nested Attention Network (LG-DNANet) for IST detection. The proposed network consists of a Pixel Attention Guided Feature Extraction Module (PAG-FEM), a Channel Attention Guided Feature Fusion Module (CAG-FFM), and a detection module. Firstly, the pixel attention-guided feature extraction module utilizes the DNIM dense nested blocks from the DNANet as the backbone, integrating both channel and pixel attention mechanisms. This method focuses on the semantic and positional information of the targets, yielding semantic features that emphasize the positions of small targets. Secondly, the channel attention guided feature fusion module employs upsampling and convolution operations to align the feature sizes, while utilizing the channel attention mechanism to obtain effective channel information. Then, these features are fused through stacking, addition, and averaging operations to obtain more discriminative features. Finally, the detection module uses eight-connected neighborhood clustering method to obtain the centroid coordinates of the targets for subsequent detection evaluation.Three datasets are utilized to verify our method, and experimental results show that our method performs better than other advanced methods. © 2008-2012 IEEE.
  Accession Number: 20244117175096
• Record 4 of
  
  Title:Hybrid optical-electronic compensation of fiber nonlinearity for long-haul coherent optical transmission
  
  Author(s):Tong, Xiaogang(1); Huang, Wei(2); Cao, Weiwei(3); Zhang, Junsheng(1); Zhang, Xiaojuan(1)
  Source:Journal of Optical Communications
  Volume:   Issue:   DOI: 10.1515/joc-2024-0110  Published: 2024  
  Abstract:From the concepts of the dispersion-folded digital backward propagation (DBP) and optical phase conjugation (OPC), a hybrid optical-electronic nonlinearity-compensation scheme is proposed to enhance the system performance of the dispersion-managed transmission. The computational complexity of the proposed scheme, compared with that of the conventional DBP method, is reduced significantly while the performance penalty is negligible. The compensation efficiency of the proposed scheme has been validated in a 5 (and 9)-channel PM-16QAM system at 256 » Gbit/s. © 2024 Walter de Gruyter GmbH, Berlin/Boston 2024.
  Accession Number: 20242616319208
• Record 5 of
  
  Title:CdSe Quantum Dots Supported on Sb2S3 Nanorods as S-Scheme Heterojunction Photoanode in Photoelectrochemical Cells
  
  Author(s):Ma, Zhen(1); Yang, Yuanhao(1); Wei, Xueling(1); Li, Qiujie(1); Zhang, Dekai(1); Wang, Yishan(2); Liu, Enzhou(3); Miao, Hui(1)
  Source:ACS Applied Nano Materials
  Volume:   Issue:   DOI: 10.1021/acsanm.4c05053  Published: 2024  
  Abstract:The narrow bandgap semiconductor Sb2S3 has been extensively utilized in solar cells for its impressive light absorption coefficient and carrier mobility. However, a large number of deep energy defects provide carrier recombination sites that limit its photoelectrochemical (PEC) performance. In this study, Sb2S3 nanorods (NRs) and CdSe quantum dots (QDs) were successfully prepared, and Sb2S3/CdSe-annealed quasi-one-dimensional heterojunction photoanodes with the S-scheme were constructed. The Sb2S3/CdSe-annealed composite photoelectrode achieves a 12 times increase in photocurrent density compared to the 0.4 mA cm-2 of the Sb2S3 photoelectrode. Overall, the synergistic effect of the [hk1]-oriented Sb2S3 NRs and the S-scheme heterojunction promotes carrier transport, achieving a spatial separation of photogenerated carriers and efficiently weakening the recombination of the electron-hole pair. This study provides a simple method for the low-cost development of Sb2S3 NRs with [hk1] orientation and an idea to enhance its development in the PEC water splitting direction. © 2024 American Chemical Society.
  Accession Number: 20244217217625
• Record 6 of
  
  Title:Large Field of View and Isotropic Light Sheet Microscopy with Aberration-Free Tunable Foci
  
  Author(s):Wang, Yue(1,2); Gong, Jingrui(1,2); Xu, Ning(1,2); Yan, Shaohui(3); Dong, Dashan(1,2); Shi, Kebin(1,2,4,5)
  Source:Laser and Photonics Reviews
  Volume:   Issue:   DOI: 10.1002/lpor.202400214  Published: 2024  
  Abstract:Light-sheet microscopy stands out as a powerful tool in biological imaging due to its exceptional performance in fluorescence imaging. However, achieving both high sectioning performance and a vast field of view (FOV) poses a fundamental challenge in conventional light-sheet microscopy. The light-sheet thickness is typically constrained to 1 µm for a wide FOV, potentially compromising resolution. To address this limitation, an axial scanning light-sheet microscopy (ASLM) technique integrated with aberration-free tunable foci to enable high-NA excitation while maintaining a generous FOV, is introduced. The proposed scheme successfully achieves isotropic resolution of 280 nm in a 3D imaging system, encompassing a FOV of 80 × 80 µm and an impressive imaging speed of 80 ms per frame. These remarkable characteristics underscore the immense potential of ASLM for high- spatiotemporal resolution imaging. © 2024 Wiley-VCH GmbH.
  Accession Number: 20244117178470
• Record 7 of
  
  Title:Topology optimization design of surface radar absorbing coatings
  
  Author(s):Chen, Fei(1); Zhu, Jihong(2); Li, Fu(1); Lu, Di(1); Yu, Jirui(1); Guo, Song(1); Yang, Jianfeng(1); Lv, Baogang(1); Xue, Bin(1)
  Source:Engineering Optimization
  Volume:   Issue:   DOI: 10.1080/0305215X.2024.2349108  Published: 2024  
  Abstract:In this study, a topology optimization method is proposed to design the layout of the radar absorbing coatings (RACs) outside the surface. The radar cross section (RCS) of a structure with RACs is evaluated by the physical optics method. A material interpolation model oriented to the relative permittivity and relative permeability of RACs is established, while the sensitivity of the RCS with respect to the design variables is derived analytically. With the objective of minimizing the RCS at the specified incident angles and the constraint of the material usage, the strategy is implemented based on a gradient-based algorithm and the so-called three-field density method. Additionally, the phenomenon of the RCS increasing in certain regions when RACs are applied is explained in detail. Finally, the effectiveness of the proposed method is demonstrated by two numerical examples. © 2024 Informa UK Limited, trading as Taylor & Francis Group.
  Accession Number: 20243216815510
• Record 8 of
  
  Title:Near-field characterization and failure analysis of broad-area laser diode with optical feedback
  
  Author(s):Miao, Xinlian(1,2,3); Xu, Zibang(1,2,3); Tang, Song(4); Liu, Yuxian(5); Yang, Guowen(4); Yuan, Xiao(1,2,3)
  Source:Proceedings of SPIE - The International Society for Optical Engineering
  Volume: 13179  Issue:   DOI: 10.1117/12.3031600  Published: 2024  
  Abstract:Optical feedback may cause accelerated degradation as well as catastrophic optical damage in high-power Laser diodes, directly limiting their output optical power and lifetime. Near-field distribution change caused by optical feedback has high relevance with the reliability and is worthy to be studied. In this study, the influence of optical feedback on the near-field distribution of the laser diode is investigated, as well as the influence on the device failure. A feedback light testing system is successfully established, which integrates power monitoring, spectral measurement, and near-field assessment. Through an investigation into the influence of feedback light, it was observed that it induces instability in the near-field distribution, leading to temporal variations. Under conditions of strong feedback, a stable near-field peak emerged. At even higher current levels, a clear correspondence was identified between the near-field peak and the point of failure. These findings offer valuable insights for the understanding of the influence of optical feedback on the near-field distribution of the laser diode and its reliability. © 2024 SPIE.
  Accession Number: 20243216830273
• Record 9 of
  
  Title:An Intersection Measurement Method With Two Optoelectronic Pods for Drop Point Measurement in Far Seas
  
  Author(s):Xuezheng, Lian(1,2,3); Meilin, Xie(1,2,3); Wei, Huang(1,2,3); Kai, Liu(1,2,3); Heng, Shi(1,2,3)
  Source:Proceedings of SPIE - The International Society for Optical Engineering
  Volume: 13157  Issue:   DOI: 10.1117/12.3013196  Published: 2024  
  Abstract:Drop point measurement precision is one of the core indexes to evaluate the combat effectiveness of weapons. With the development of experimental equipment, the experimental training venue has been expanded to the far sea. Due to the little known data in the far sea area and the measuring area, the measurement methods are limited. In response to the characteristics of the high seas, this paper proposes a method of mounts an optoelectronic pod on a drone and utilizes two drones for collaborative intersection measurement, achieving high-precision landing point measurement and high reliable data acquisition rate. This paper provides a detailed comparison between the traditional H-E-A single station angle measurement and distance measurement methods, the collinear equation based non ranging information positioning method, and the dual aircraft intersection positioning measurement principle combined with RLS filtering algorithm. At the same time, this paper analyzed various factors that affect the accuracy of positioning measurement. Through actual measurement verification of simulated targets, this method achieved a drop point measurement accuracy of 2m within a range of 3Km and a measurement accuracy of over 95%, which is significantly improved compared to traditional methods. The method provides data support for evaluating weapon effectiveness and obtaining field situation, and can also serve as auxiliary means for personnel search and rescue, debris search, etc., greatly improving the fusion ability of multidimensional data and enhancing the independent innovation and support ability of far sea measurement equipment. © 2024 SPIE.
  Accession Number: 20242016100384
• Record 10 of
  
  Title:Measurement of deep hole verticality by monocular vision
  
  Author(s):Zhu, Hui(1); Li, Hua(1); Liu, Wei(1); Li, Zhaohui(1); Tan, Wenlong(2)
  Source:Proceedings of SPIE - The International Society for Optical Engineering
  Volume: 13182  Issue:   DOI: 10.1117/12.3030360  Published: 2024  
  Abstract:To propose a measurement method for the verticality of deep hole based on monocular vision. The coordinate conversion matrix of pentaprism circumferential scanning is derived, and the circumferential scanning trajectory and characteristics of the targets are simulated and analyzed. Based on the visual axis, the normal direction of the measurement datum is constructed to accurately compensate the error between the camera visual axis and the tube datum. For the simulated tube with a radius of 956.21mm, a thickness of 999.55mm and a verticality of 0 mm, the verticality accuracy measured by the system can reach 0.03mm. The actual test shows that the method of measuring the verticality of deep hole with monocular vision is effective and feasible. The system is easy to operate and highly automated, which can greatly improve the measurement efficiency and ensure the measurement accuracy. It is of great significance to the production and measurement of deep holes in nuclear tube sheet. © 2024 SPIE.
  Accession Number: 20242516298474
• Record 11 of
  
  Title:Real-time Target Detection and Velocity Measurement for Spacecraft Docking Based on Improved Arc-support LSs Ellipse Detection
  
  Author(s):Wu, Xiongzhi(1,2,4); Wu, Jiaxin(1,2,4); Zhang, Haifeng(1,4); Duan, Yingni(3); Meng, Han(1,4)
  Source:Proceedings of SPIE - The International Society for Optical Engineering
  Volume: 13179  Issue:   DOI: 10.1117/12.3031610  Published: 2024  
  Abstract:With the development of China's space station, rendezvous and docking between spacecraft and the station have become more frequent. Smooth and safe docking speed is important for the effectiveness of docking missions. In this context, vision-based docking speed measurement comes into view. Visual measurement is a commonly used method. It is a non-contact measurement method, which is realized by optical measurement principles and equipment to measure the structure under test. We propose an improved ellipse detection method for arc-support LSs.The method first forms an arc support group, verifies this prior knowledge on the basis of the arc support group according to the feature that the ellipse cross target is always in the center of the image, and sets a prior box to narrow the detection range of the ellipse. and then generates an initial ellipse set using two complementary methods, and after selecting the significant ellipse candidates and refining them as the detection points, achieves an efficient and high-quality ellipse detection. The docking speed calculation formula was established based on the physical imaging model. It is validated on our own docking simulation video and the real public Shenzhou XVI and Shenzhou XVII spacecraft docking videos, with a recall of 0.9353 and an FPS of 8.513 on the simulation video, which is more efficient and high-quality than other traditional ellipse detection methods, and the speed measurement errors are 5.8% and 3.6% on the two real public videos, which improves the spacecraft docking speed measurement robustness. © 2024 SPIE.
  Accession Number: 20243216830238
• Record 12 of
  
  Title:Effect of the magnetic field on spatio-temporal resolution of a streak tube with single-lens focusing system
  
  Author(s):Wang, Ziyang(1); Tian, Liping(1); Shen, Lingbin(1); Chen, Liu(1); Lu, Weijie(1); Gao, Chunyu(1); Yang, Huizhen(1); Xue, Yanhua(2); Chen, Ping(2); Tian, Jinshou(2)
  Source:Proceedings of SPIE - The International Society for Optical Engineering
  Volume: 13231  Issue:   DOI: 10.1117/12.3040027  Published: 2024  
  Abstract:The streak tube with a large effective photocathode area, high spatial resolution, and high temporal resolution are essential for improving the detection accuracy of the streak tube imaging lidar (STIL). In this paper, a three-dimensional streak tube with single-lens focusing system is developed in CST STUDIO SUITE to systematically investigate the dependences of the dynamic spatio-temporal resolution on the geomagnetic fields. The electro-magnetic distribution in streak tube is calculated by adopting discretized Maxwell’s equations and Finite integral method (FIM). Monte Carlo (M-C) sampling is used to determine the initial distribution of electrons in the visible photocathode. The photoelectrons trajectories are tracked by using the particle-in-cell (PIC) method. All simulations are conducted under both shield (no magnetic field applied with the 3D model) and unshielded (49524.5 nT magnetic field applied with the 3D model) conditions. The results show that the shielding structure can significantly reduce the spatial dispersion of streak tube, and greatly improve the spatial resolution. In addition, there is little difference in temporal resolution, with or without a shielded structure. © 2024 SPIE.
  Accession Number: 20243617008247