2019
2019
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Record 325 of
Title:Multidimensional Manipulation of Photonic Spin Hall Effect with a Single-Layer Dielectric Metasurface
Author(s):Li, Siqi(1,2); Li, Xingyi(1,2); Wang, Guoxi(1,2); Liu, Sheng(3); Zhang, Lingxuan(1,2); Zeng, Chao(1,2); Wang, Leiran(1,2); Sun, Qibing(1,2); Zhao, Wei(1,2); Zhang, Wenfu(1,2)Source: Advanced Optical Materials Volume: 7 Issue: 5 DOI: 10.1002/adom.201801365 Published: March 5, 2019Abstract:The photonic spin Hall effect, originating from photonic spin–orbit interactions, has attracted considerable research interest due to its potential for applications in spin-controlled nanophotonics. However, most research efforts have focused only on 1D modulation, including transverse or longitudinal spin-dependent splitting. Here, a novel method is proposed for multidimensional spin-dependent splitting on a single-layer dielectric metasurface. Due to the interplay of the Pancharatnam–Berry phase and dynamic phase, the longitudinal focusing and transverse shifting of the different spin state photons can be simultaneously achieved. Moreover, the conjugated characteristic of the modulated phases of Pancharatnam–Berry phase metasurfaces for different spin photons can be broken, and both symmetric and asymmetric transverse spin-dependent splitting are obtained with the proposed method. This method can be used for the multidimensional and flexible manipulation of spin photons and has potential in spin-controlled nanophotonics, ranging from optical communication to beam shaping and optical sensors. ? 2018 WILEY-VCH Verlag GmbH & Co. KGaA, WeinheimAccession Number: 20190106330639 -
Record 326 of
Title:High-resolution reconstruction of shortwave infrared polarimetric images using the intensity information of visible images
Author(s):Liang, Jian(1,2,3); Ju, Haijuan(2); Ren, Liyong(2,4); Zhang, Wenfei(2); Yang, Liming(2); Bai, Zhaofeng(2); Liang, Rongguang(3)Source: Applied Optics Volume: 58 Issue: 18 DOI: 10.1364/AO.58.004866 Published: 2019Abstract:Shortwave infrared (SWIR) polarimetric imaging has been found very effective in various applications. However, the low resolution of the SWIR camera severely limits the capacity of this technique. Image reconstruction methods have been developed to improve the spatial resolution, but these methods typically do not consider the polarized information that the images may contain. In this paper, we propose a high-resolution reconstruction method for SWIR images based on the spatial information of visible images without losing polarized information in the SWIR image. Experimental results demonstrate that this method is feasible to reconstruct high-resolution polarized SWIR images. We have also demonstrated its potential application in image fusion. ? 2019 Optical Society of America.Accession Number: 20192707127793 -
Record 327 of
Title:Joint Learning of Fuzzy k-Means and Nonnegative Spectral Clustering With Side Information
Author(s):Zhang, Rui(1); Nie, Feiping(2); Guo, Muhan(2); Wei, Xian(3); Li, Xuelong(2)Source: IEEE Transactions on Image Processing Volume: 28 Issue: 5 DOI: 10.1109/TIP.2018.2882925 Published: May 2019Abstract:As one of the most widely used clustering techniques, the fuzzy k-means (FKM) assigns every data point to each cluster with a certain degree of membership. However, conventional FKM approach relies on the square data fitting term, which is sensitive to the outliers with ignoring the prior information. In this paper, we develop a novel and robust fuzzy k-means clustering algorithm, namely, joint learning of fuzzy k-means and nonnegative spectral clustering with side information. The proposed method combines fuzzy k-means and nonnegative spectral clustering into a unified model, which can further exploit the prior knowledge of data pairs such that both the quality of affinity graph and the clustering performance can be improved. In addition, for the purpose of enhancing the robustness, the adaptive loss function is adopted in the objective function, since it smoothly interpolates between 1-norm and 2-norm. Finally, experimental results on benchmark datasets verify the effectiveness and the superiority of our clustering method. ? 2018 IEEE.Accession Number: 20184906173775 -
Record 328 of
Title:Optimization design of space mirror support based on topology optimization method
Author(s):Xu, Wen Jing(1,2); Wang, Wei(1,2); Qu, Yan Jun(1,2); Liu, Bei(1,2); Li, Xu Peng(1,2); Ma, Xiao Zhe(1,2)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 11170 Issue: DOI: 10.1117/12.2532694 Published: 2019Abstract:An optimal design method for lateral support structure of space telescope based on topology optimization theory and substructure method is presented in this paper. Introduced how to simplify the finite element model by substructure method in the process of analysis. Topology optimization is performed on the reduced model. Based on the variable density method (SIMP method), a mathematical model of continuum structure topology optimization is created to achieve efficient use of materials. Design a new type of mirror support structure. Consider the shape of the mirror which under axial gravity, radial gravity and temperature load conditions. The fundamental frequency of the mirror and the displacement of the rigid body are constrained, and the manufacturability of the topological results are also considered. The static and modal analysis of the structure using finite element method shows that the basic frequency and the shape precision of the mirror can meet the design requirements (the fundamental frequency f >120Hz, the surface accuracy is better than λ/60 RMS, λ/10 PV). This shows the feasibility of the method proposed in this paper in the design. ? 2019 SPIE.Accession Number: 20193107262587 -
Record 329 of
Title:Evaluation on mirror seeing for AIMS solar telescope
Author(s):Xia, Yongbo(1,2); Xie, Yongjun(1); Wang, Peng(1); Mao, Xiang-Long(1); Song, Xuding(2); Xu, Songbo(1)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 11052 Issue: DOI: 10.1117/12.2521781 Published: 2019Abstract:The primary mirror of AIMS solar telescope is heated during the observation of the sun, leading to temperature rise of the primary mirror. The temperature difference between the primary mirror and the surrounding air may cause the seeing effect (mirror seeing), which is one of the key factors influencing the image qualities of the telescope. In this paper, the temperature fields of the primary mirror and its surrounding air are simulated by the CFD software on the conditions of different ambient wind speeds, different observational angels of the primary mirror, and the duration of observation. According to the calculation of temperature fields, the mirror seeing on different conditions are analyzed and the necessity of thermal control of the primary mirror is evaluated. The evaluation of the mirror seeing is very helpful for the design of thermal control of the primary mirror. ? 2019 SPIE.Accession Number: 20190806535044 -
Record 330 of
Title:Modeling and analysis of image rotation for the AIMS solar optical telescope
Author(s):Gong, Yinbing(1,2); Xie, Yongjun(1); Dong, Rongguang(1); Mao, Xianglong(1); Zhang, Tao(2); Xu, Songbo(1)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 11052 Issue: DOI: 10.1117/12.2520199 Published: 2019Abstract:The AIMS, a solar telescope with a primary mirror of 1m in diameter, is designed with an off-axis Gregorian optical system and an alt-az mounting structure. The image rotation of the AIMS will be produced both due to alt-az mounting and the movement of plane mirrors system during the monitoring of the sun. Therefore, a derotator is planned to correct and compensate the image rotation to make the terminal instruments of the AIMS work properly. The image rotation in astronomical telescopes consists of the object field rotation and the image field rotations. In this paper, the rotation of the object field for the AIMS is presented and calculated. The image field rotation due to the plane mirrors system with the movement of azimuth axis and altitude axis of the AIMS is theoretically determined by using the ray tracing and vector matrix method. The relationships between the image filed rotation and the variation of the azimuth and altitude of the telescope are discussed. This work may be very helpful to evaluate the deroation methods for the AIMS and will provide an important theoretical support for precision control of the derotator to eliminate the image rotation in real time. ? 2019 SPIE.Accession Number: 20190806534737 -
Record 331 of
Title:Prediction of penetration depth of earth penetrator based on neural network
Author(s):Zhuo, Chen(1); Huixiang, Sun(1); Yingwu, Wang(2); Huan, Niu(1)Source: IOP Conference Series: Earth and Environmental Science Volume: 267 Issue: 3 DOI: 10.1088/1755-1315/267/3/032004 Published: June 10, 2019Abstract:An artificial intelligence neural network model is established in this essay to seek a more general method for predicting penetration depth of earth penetrator, to comprehensively analyze the effect of various parameters on penetration depth as well as to predict the penetration depth of earth penetrator.This paper, by means of numerical simulation, and determined the ordnance penetrator warhead curvature radius, the length of the projectile, the density of the projectile,the density of the target protective layer, the elastic modulus of the target protective layer and the hit velocity of the earth penetrator.This six key parameters as the input data of neural network model, and by using numerical simulation to obtain the data needed for training the neural network model samples. According to the characteristics of six input data and one output data of the neural network model, the possible structure of the neural network model is set, and the optimal model structure is selected through training. We built neural network model to forecast the ordnance penetrator penetration depth, analyzes the six key parameter's influence on the depth of penetration, the results show that reducing the warhead curvature radius, increasing the length and density of the projectile, properly increasing the impact velocity of the projectile can improve the penetration ability of the earth penetrating projectile, and increasing the density and elastic modulus of the target protective layer can improve the anti-penetration ability of the protective layer. ? Published under licence by IOP Publishing Ltd.Accession Number: 20192607097436 -
Record 332 of
Title:A Molecular Dynamics Study on Self-Assembly of Single-Walled Carbon Nanotubes: From Molecular Morphology and Binding Energy
Author(s):Zhang, Jianwei(1,2,3); Cui, Jianlei(1,2,4,5); Cheng, Yang(1,2); Wang, Wenjun(1,3); He, Xiaoqiao(6); Mei, Xuesong(1,3)Source: Advanced Materials Interfaces Volume: 6 Issue: 19 DOI: 10.1002/admi.201900983 Published: October 1, 2019Abstract:Molecular dynamics simulations are used to reveal the adsorption behavior of modified single-walled carbon nanotubes (M-SWNTs) on the functionalized surfaces (F-surfaces) bound to a silicon dioxide substrate, in order to illustrate the mechanism of patterned self-assembly of SWNTs on the atomic scale. Noncovalent modification strategy with surfactants is adopted to investigate the structural transition of the surfactant on SWNTs in aqueous solution. Core/shell hybrid structures are formed ultimately by the surfactant scrolling onto SWNTs periphery. Two different kinds of silanes are used to control the wettability of the F-surfaces from hydrophobic to hydrophilic. An excluded-volume constraints algorithm is employed to calculate the global energy minimum to rationalize the driving force controlling the behavior evolution. The mechanisms for self-assembly are illustrated in two segments in detail that the electrostatic attraction starts the self-assembly program on the hydrophilic surface, while van der Waals interaction plays an important role in the behavior of nonassembly to the hydrophobic surface. The results are not only helpful to understand many phenomena in the self-assembly process on the atomic scale but also will provide meaningful guidance in fabrication of SWNTs patterns to keep fidelity. ? 2019 WILEY-VCH Verlag GmbH & Co. KGaA, WeinheimAccession Number: 20193607390811 -
Record 333 of
Title:Study on spectral transfer characteristics of double AOTF imaging spectrometer acoustooptic crystals
Author(s):Chang, Lingying(1); Jin, Mengzhu(1); Song, Jingjing(1); Yao, Dawei(2); Qiu, Yuehong(2)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 11337 Issue: DOI: 10.1117/12.2544943 Published: 2019Abstract:Optical instruments usually use optical transfer functions to represent the target image quality. It can represent the spatial characteristics of the imaging spectrometer and the transmission characteristics of signal output and input in the frequency. However, for the imaging spectrum instrument, it can obtain both the spectral and spatial information at the same time, so it is also necessary to use the spectral transfer function to represent the spectral characteristics of the imaging spectrometer. In this paper, first, the working principle of double AOTF imaging spectrometer was introduced. Second, the spectral transfer function of double AOTF imaging spectrometer acoustics optic crystals was established. It is obtained by integrating the spectral transmission function within the wave difference range when the wave number difference is greater than zero. Last, the spectral transfer function in the 400nm-900nm of double AOTF imaging spectrometer acoustic optic crystals with the central wave difference and same were calculated. The results show that the wavelength difference was higher than that of the small spectral transfer function.The research results of this paper provided reference for the design and research for new imaging spectrometer. ? 2019 SPIE.Accession Number: 20200408062481 -
Record 334 of
Title:External pressure buckling analysis of large pressure vessels
Author(s):Xu, Wenjing(1,2)Source: Journal of Physics: Conference Series Volume: 1303 Issue: 1 DOI: 10.1088/1742-6596/1303/1/012019 Published: September 2, 2019Abstract:In the external buckling analysis, it is significant to determine the magnitude of the critical buckling load value. This paper introduces a method based on ANSYS finite element method for external pressure buckling analysis of pressure vessels and determination the critical loads. Eigenvalue buckling analysis and nonlinear buckling analysis are introduced. After the initial selection of structural parameters and reasonable structural design, ANSYS software was used to establish a reasonable and valid 3D solid model. Check the design and hydraulic condition is necessary after establishing the 3D solid model. It is the precondition of buckling analysis. After passing the internal pressure strength test, external buckling analysis will be start. In this paper, the buckling critical load of a 1500m3 spherical tank is obtained by comparing the eigenvalue buckling analysis with the nonlinear buckling. And the value of nonlinear buckling is lower. Because nonlinear buckling analysis considers the flaws of the actual structure. Therefore, nonlinear bucking analysis is more suitable for practical engineering analysis. ? 2019 IOP Publishing Ltd.Accession Number: 20193907471119 -
Record 335 of
Title:Multi-spectral image level-by-level registration algorithm based on A-KAZE feature
Author(s):Li, Hongyu(1,2); Xue, Bin(1); Li, Yongfang(2); Tao, Jinyou(1); Zhou, Shaopan(1); Guan, Zhao(1)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 11023 Issue: DOI: 10.1117/12.2521791 Published: 2019Abstract:Aiming at the problem that he gray level of different spectral images varies greatly and the traditional feature extraction algorithm is difficult to maintain the local precision and edge detail of the image, a multi-channel multi-spectral image registration method based on A-KAZE algorithm. In the registration process, the Fast Explicit Diffusion (FED) numerical analysis framework is used to solve the nonlinear diffusion filter equation, and the nonlinear scale space is constructed. The feature points are obtained by calculating the Hessian matrix of each pixel; The invariant image feature vectors are constructed by the Modified-Local Difference Binary (M-LDB) descriptor. Then, the feature vectors are matched by KNN using Hamming distance, and the mismatched points are eliminated by M-estimator Sample Consensus (MSAC). Finally, the transformation matrix is calculated based on projection transformation model. For multi-channel multi-spectral images, the optimal registration route is calculated by level-by-level registration method, and the image registration is realized by registration strategy and transformation matrix. Multispectral phenological observation data were selected to verify the image registration effect of the algorithm, and compared with SIFT, SURF, KAZE algorithm. Experimental results show that this method can achieve sub-pixel registration accuracy on any two images, and has strong robustness and faster speed. ? 2019 SPIE.Accession Number: 20191506748630 -
Record 336 of
Title:Large-scale 3D imaging of insects with natural color
Author(s):Qian, Jia(1,2); Dang, Shipei(1,2); Wang, Zhaojun(1,2); Zhou, Xing(1,2); Dan, Dan(1); Yao, Baoli(1); Tong, Yijie(2,3); Yang, Haidong(3); Lu, Yuanyuan(2,3); Chen, Yandong(2,3); Yang, Xingke(3); Bai, Ming(3); Lei, Ming(1)Source: Optics Express Volume: 27 Issue: 4 DOI: 10.1364/OE.27.004845 Published: 2019Abstract:High-resolution 3D imaging technology has found a number of applications in many biological fields. However, the existing 3D imaging tools are often too time-consuming to use on large-scale specimens, such as centimeter-sized insects. In addition, most 3D imaging systems discard the natural color information of the specimens. To surmount these limitations, we present a structured illumination-based approach capable of delivering large field-of-view three-dimensional images. With this approach, 580nm lateral resolution fullcolor 3D images and 3D morphological data in the size range of typical insect samples can be obtained. This method provides a promising approach that can be used to support many different types of entomological investigations, including taxonomy, evolution, bionics, developmental biology, functional morphology, paleontology, forestry, etc. ? 2019 Optical Society of America.Accession Number: 20190906560130