2021
2021
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Record 61 of
Title:In situ lunar phase curves measured by Chang'E-4 in the von Kármán Crater, South Pole-Aitken basin
Author(s):Jiang, Te(1); Hu, Xiaoyi(1); Zhang, Hao(1,2); Ma, Pei(1); Li, Chunlai(3); Ren, Xin(3); Liu, Bin(3); Liu, Dawei(3); Yang, Jianfeng(4); Xue, Bin(4); Jin, Weidong(5); Zhu, Meng-Hua(6); Huang, Changning(7); Lin, Hongyu(7)Source: Astronomy and Astrophysics Volume: 646 Issue: DOI: 10.1051/0004-6361/202039252 Published: February 1, 2021Abstract:Context. The Yutu-2 rover of the Chang'E-4 (CE-4) mission measured the lunar phase curves in the Von Kármán crater, South Pole-Aitken basin. Aims. We aim to study the photometric properties of the regolith at CE-4's landing site and compare them with those of Chang'E-3 (CE-3) in order to understand the regolith physical properties of the two landing sites. Methods. We extracted the insitu lunar phase curves measured by CE-4 with a very wide phase angle coverage (1°-144°) and performed photometric model inversions using both the Hapke model and the Lumme-Bowell model. Results. Compared with the CE-3 measurement taken in Mare Imbrium, the CE-4 phase curves show the colorimetric opposition effect and have a steeper and narrower opposition spike. The surface regolith at the CE-4 site is much darker, more porous, more forward scattering, and has a larger slope angle (Hapke model) than that of CE-3. Conclusions. The CE-4 site may have experienced more space weathering alterations than the CE-3 site, which is consistent with their different surface model ages (～3.6 Ga for CE-4 and ～3 Ga for CE-3). ? ESO 2021.Accession Number: 20210609875212 -
Record 62 of
Title:Controlled asymmetric bidirectional quantum teleportation of two- and three-qubit states
Author(s):Huo, Guangwen(1); Zhang, Tongyi(2); Zha, Xinwei(3); Zhang, Xiuxing(1); Zhang, Meizhi(3)Source: Quantum Information Processing Volume: 20 Issue: 1 DOI: 10.1007/s11128-020-02956-3 Published: January 2021Abstract:We propose a protocol of asymmetric controlled bidirectional quantum teleportation of two- and three-qubit states. That is to say, Alice wants to teleport an arbitrary two-qubit state to Bob, and Bob wants to teleport an arbitrary three-qubit state for Alice via the control of supervisor Charlie. By using the eleven-qubit entangled state as the quantum channel, Alice can teleport an arbitrary two-qubit state for Bob and Bob can teleport an arbitrary three-qubit state for Alice simultaneously. ? 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC part of Springer Nature.Accession Number: 20210209763503 -
Record 63 of
Title:An uncoupled theory of FG nanobeams with the small size effects and its exact solutions
Author(s):Pei, Y.L.(1,2); Li, L.X.(1)Source: Archive of Applied Mechanics Volume: 91 Issue: 4 DOI: 10.1007/s00419-020-01849-2 Published: April 2021Abstract:Due to unphysical coupling induced by the material inhomogeneity, FG (functionally graded) nanobeam problems were formulated in a very complex way so that they cannot be analytically solved. In this paper, an uncoupled theory is proposed for FG nanobeams considering their small size effects. First, with the aid of the neutral axis, the axial displacement is expressed in terms of generalized displacements for FG nanobeams. Based on the nonlocal strain gradient theory, the generalized stresses and strains are accordingly defined and uncoupled constitutive relations are derived. Based on the principle of virtual work, an uncoupled theory is eventually established, including governing equations and boundary conditions. Within the present framework, analytical solutions to FG nanobeams are obtained for the first time for general boundary conditions. These solutions not only re-evaluate the previous results but shed light on the small size effects of FG nanobeams. ? 2021, Springer-Verlag GmbH Germany, part of Springer Nature.Accession Number: 20210109715973 -
Record 64 of
Title:Program-controlled single soliton microcomb source
Author(s):Wang, Xinyu(1,2); Xie, Peng(1,2); Wang, Weiqiang(1,2); Wang, Yang(1,2); Lu, Zhizhou(1,2); Wang, Leiran(1,2); Chu, Sai T.(3); Little, Brent E.(1,2); Zhao, Wei(1,2); Zhang, Wenfu(1,2)Source: Photonics Research Volume: 9 Issue: 1 DOI: 10.1364/PRJ.408612 Published: January 1, 2021Abstract:Soliton microcombs (SMCs) are spontaneously formed in a coherently pumped high-quality microresonator, which provides a new tool for use as an on-chip frequency comb for applications of high-precision metrology and spectroscopy. However, generation of SMCs seriously relies on advanced experimental techniques from professional scientists. Here, we experimentally demonstrate a program-controlled single SMC source where the intracavity thermal effect is timely balanced using an auxiliary laser during single SMC generation. The microcomb power is adopted as the criteria for microcomb states discrimination and a forward and backward thermal tuning technique is employed for the deterministic single SMC generation. Further, based on a closed-loop control system, the repetition rate stability of the SMC source improved more than 20 times and the pump frequency can be continuously tuned by simply changing the operation temperature. The reliability of the SMC source is verified by consecutive 200 generation trials and maintaining over 10 h. We believe the proposed SMC source will have significant promising influences in future SMC-based application development. ? 2020 Chinese Laser PressAccession Number: 20210209754479 -
Record 65 of
Title:Rapid Image Reconstruction of Structured Illumination Microscopy Directly in the Spatial Domain
Author(s):Dan, Dan(1); Wang, Zhaojun(1); Zhou, Xing(1); Lei, Ming(1,2); Zhao, Tianyu(1); Qian, Jia(1); Yu, Xianghua(1); Yan, Shaohui(1); Min, Junwei(1); Bianco, Piero R.(3); Yao, Baoli(1)Source: IEEE Photonics Journal Volume: 13 Issue: 1 DOI: 10.1109/JPHOT.2021.3053110 Published: February 2021Abstract:Super-resolution structured illumination microscopy (SIM) routinely performs image reconstruction in the frequency domain using an approach termed frequency-domain reconstruction (FDR). Due to multiple Fourier transforms between the spatial and frequency domains, SIM suffers from low reconstruction speed, constraining its applications in real-time, dynamic imaging. To overcome this limitation, we developed a new method for SIM image reconstruction, termed spatial domain reconstruction (SDR). SDR is intrinsically simpler than FDR, does not require Fourier transforms and the theory predicts it to be a rapid image reconstruction method. Results show that SDR reconstructs a super-resolution image 7-fold faster than FDR, producing images that are equal to either FDR or the widely-used FairSIM. We provide a proof-of-principle using mobile fluorescent beads to demonstrate the utility of SDR in imaging moving objects. Consequently, replacement of the FDR approach with SDR significantly enhances SIM as the desired method for live-cell, instant super-resolution imaging. This means that SDR-SIM is a 'What You See Is What You Get' approach to super-resolution imaging. ? 2009-2012 IEEE.Accession Number: 20210409829936 -
Record 66 of
Title:Apparatus for generation of nanojoule-class water-window high-order harmonics
Author(s):Nishimura, Kotaro(1,2); Fu, Yuxi(1,3); Suda, Akira(2); Midorikawa, Katsumi(1); Takahashi, Eiji J.(1)Source: Review of Scientific Instruments Volume: 92 Issue: 6 DOI: 10.1063/5.0045342 Published: June 1, 2021Abstract:In our recent study [Fu et al., Commun. Phys. 3(1), 92 (2020)], we have developed an approach for energy-scaling of high-order harmonic generation in the water-window region under a neutral-medium condition. More specifically, we obtained a nanojoule-class water-window soft x-ray harmonic beam under a phase-matching condition. It has been achieved by combining a newly developed terawatt-class mid-infrared femtosecond laser and a loose-focusing geometry for high-order harmonic generation. The generated beam is more than 100 times intense compared to previously reported results. The experimental setup included two key parts: a terawatt mid-infrared femtosecond driving laser [Fu et al., Sci. Rep. 8(1), 7692 (2018)] and a specially designed gas cell. Despite the dramatic drop in the optimal gas pressure for phase-matching due to loose-focusing geometry, it still reached the 1?bar level for helium. Thus, we have designed a double-structured pulsed-gas cell with a differential pumping system, which enabled providing sufficiently high gas pressure. Moreover, it allowed reducing gas consumption significantly. A robust energy-scalable apparatus for high-order harmonic generation developed in this study will enable the generation of over ten-nanojoule water-window attosecond pulses in the near future. ? 2021 Author(s).Accession Number: 20212410488576 -
Record 67 of
Title:Direct femtosecond laser inscription of an IR fluorotellurite fiber Bragg grating
Author(s):Liu, Lutao(1,2); Chen, Fengyi(3); Xiao, Xusheng(1,2); Li, Xingyong(3); Wang, Ruohui(3); Liu, Chengzhen(1,2); Guo, Haitao(1,2)Source: Optics Letters Volume: 46 Issue: 19 DOI: 10.1364/OL.439290 Published: October 1, 2021Abstract:This study proposes a novel, to the best of our knowledge, development of fluorotellurite glass fiber Bragg gratings (FBGs). Shell-like morphology was achieved using a single femtosecond laser pulse illuminated through the fiber’s polymer coating. Different FBG fabrication methods and parameters were systematically studied to optimize performance. The fluorotellurite FBG exhibited a high sensitivity to writing laser power and reflectivity saturation effect in repetitive writing. A low-insertion-loss fluorotellurite FBG with a reflectivity of over 99% and bandwidth of less than 1 nm was successfully inscribed. The flexible inscription methods can write an FBG at any wavelength in the fluorotellurite glass transparent window, and are applicable to infrared fiber lasers or sensors. ? 2021 Optical Society of AmericaAccession Number: 20213910957017 -
Record 68 of
Title:Experimental Research on Laser Active Coherent Array Imaging through Horizontal Transimission in Real Atmosphere
Author(s):Zhang, Yu(1,2,3,4); Li, Zhiguo(1,2,3,4); Liu, Hui(1,2,3); Chen, Minglai(1,2,3); Luo, Xiujuan(1,2,3); Ma, Caiwen(1,2,3); Zhang, Huaili(5)Source: Guangzi Xuebao/Acta Photonica Sinica Volume: 50 Issue: 12 DOI: 10.3788/gzxb20215012.1201004 Published: December 25, 2021Abstract:In order to study laser array in the whole atmosphere turbulence coherent imaging ability, on the basis of all phase method such as closure, the atmospheric refractive index structure constant of HV57 model is used to calibrate the atmospheric coherence length, through the local wind speed and light road height to calculate the experimental parameters, such as local equivalent whole layer of the atmospheric turbulence level transmission distance. A laser coherent emission array with a diameter of 1.5 m equivalent aperture is developed, and the imaging experiment of a 1.2 km distant object is carried out. The imaging resolution reaches sub-arcsecond level. It is verified that the laser coherent array imaging system can suppress the influence of atmospheric turbulence and provide theoretical and technical support for the development of solid laser coherent array imaging system in the future. ? 2021, Science Press. All right reserved.Accession Number: 20220611611347 -
Record 69 of
Title:Development of a 36-element piezoelectric deformable mirror for synchrotron radiation and its surface control ability
Author(s):Yuan, De-Bo(1); Xu, Liang(2); Zhang, Wen-Bin(3); Zhou, Zhi-Yong(3); Dong, Xiao-Hao(4); Liu, Zheng-Kun(1); Zhang, Guo-Bin(1)Source: Chinese Optics Volume: 14 Issue: 6 DOI: 10.37188/CO.2021-0103 Published: November 2021Abstract:Ultra-high quality optical elements are demanded by beamlimes on fourth-generation synchrotron facilities and free-electron laser facilities. A bimorph mirror is effectively used to achieve ultra-high-precision surface profile control and wavefront correction, yet it's one of the bottlenecks of domestic techniques and must be overcome. In order to accomplish this, a 200 mm long bimorph mirror with 36 elements of piezoelectric actuators was developed. The structure parameters of the bimorph mirror were optimized by numerical simulation, and the bimorph mirror was fabricated by domestic technology. The test results show that the surface profile error and slope error of the bimorph mirror can be reduced to 1.38 nm (rms) and 240 nrad (rms), thus the nanoscale control of the mirror surface profile was realized. ? 2021, China Science Publishing & Media LTD. All right reserved.Accession Number: 20214711218115 -
Record 70 of
Title:On-chip generation of telecommunications-compatible ultrafast time-bin entangled qubits
Author(s):Yu, Hao(1,2); Chemnitz, Mario(1); Sciara, Stefania(1); Fischer, Bennet(1); Crockett, Benjamin(1); Roztocki, Piotr(1); Little, Brent E.(3); Chu, Sai T.(4); Moss, David J.(5); Aza?a, José(1); Wang, Zhiming(2); Morandotti, Roberto(1,2)Source: Optics InfoBase Conference Papers Volume: Issue: DOI: null Published: 2021Abstract:We demonstrate telecom compatible time-entangled two-photon pairs qubits using an on-chip unbalanced interferometer and spiral waveguide for state preparation/processing and generation, respectively. We show quantum interference and confirm Bell's inequality violation. ? OSA 2021, ? 2021 The Author(s)Accession Number: 20214711208024 -
Record 71 of
Title:A framework of modelling slip-controlled crack growth in polycrystals using crystal plasticity and XFEM
Author(s):Zhang, P.(1,2); Lu, S.(1); Baxevanakis, K.P.(2); Zhao, L.G.(2,3,4); Yu, T.Y.(5); Zhou, R.X.(6)Source: Journal of Physics: Conference Series Volume: 1885 Issue: 4 DOI: 10.1088/1742-6596/1885/4/042014 Published: April 28, 2021Abstract:Short cracks tend to develop at high and irregular rates compared to macroscopic cracks, making the prediction of fatigue life a challenging task. In this work, a numerical framework combining crystal plasticity model and the Extended Finite Element Method (XFEM) is applied to study the slip-controlled short crack growth in a polycrystal superalloy RR1000. The model is calibrated from experiments and used to evaluate short crack growth paths and rates. Two fracture criteria are used and compared: The onset of fracture is controlled by the total and individual cumulative shear strain respectively, and the crack grows either perpendicular to the direction of maximum principal strain or along crystallographic directions. ? Published under licence by IOP Publishing Ltd.Accession Number: 20212110381761 -
Record 72 of
Title:Two-stream network for infrared and visible images fusion
Author(s):Liu, Luolin(1,2); Chen, Mulin(3); Xu, Mingliang(4); Li, Xuelong(3,5)Source: Neurocomputing Volume: 460 Issue: DOI: 10.1016/j.neucom.2021.05.034 Published: October 14, 2021Abstract:Long-wave infrared(thermal) images distinguish the target and background according to different thermal radiation. They are insensitive to light conditions, and cannot present details obtained from reflected light. By contrast, the visible images have high spatial resolution and texture details, but they are easily affected by the occlusion and light conditions. Combining the advantages of the two sources may generate a new image with clear targets and high resolution, which satisfy requirements in all-weather and all-day/night conditions. Most of the existing methods cannot fully capture the underlying characteristics in the infrared and visible images, and ignore complementary information between the sources. In this paper, we propose an end-to-end model (TSFNet) for infrared and visible image fusion, which is able to handle the sources simultaneously. In addition, it adopts an adaptive weight allocation strategy to capture the informative global features. Experiments on public datasets demonstrate the proposed fusion method achieves state-of-the-art performance, in both global visual quality and quantitative comparison. ? 2021Accession Number: 20212910660394