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RSC advances 2024年第44期14卷 32471页

作者： Trang Thuy Nguyen Hoan Van Tran Linh Hoang Nguyen Hoang Minh Nguyen Thang Bach Phan Toan Nguyen-The Yoshiyuki Kawazoe Faculty of Physics University of Science Vietnam National University Hanoi Vietnam nguyenthuytrang@hus.edu.vn. Key Laboratory for Multiscale Simulation of Complex Systems University of Science Vietnam National University Hanoi Vietnam. School of Engineering Physics Hanoi University of Science and Technology Hanoi Vietnam. Center for Innovative Materials and Architectures Vietnam National University Ho Chi Minh City Vietnam. Vietnam National University Ho Chi Minh City Vietnam. New Industry Creation Hatchery Center Tohoku University Sendai 980-8579 Japan. Department of Physics and Nanotechnology SRM Institute of Science and Technology Kattankulathur 603203 Tamilnadu India. School of Physics Institute of Science Suranaree University of Technology 111 University Avenue Nakhon Ratchasima 30000 Thailand.

[This corrects the article DOI: 10.1039/D4RA03946G.].

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Is the winner really the best? A critical analysis of common research practice in biomedical image analysis competitions

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arXiv 2018年

作者： Maier-Hein, Lena Eisenmann, Matthias Reinke, Annika Onogur, Sinan Stankovic, Marko Scholz, Patrick Arbel, Tal Bogunovic, Hrvoje Bradley, Andrew P. Carass, Aaron Carolin Feldmann Frangi, Alejandro F. Ful, Peter M. van Ginneken, Bram Hanbury, Allan Honauer, Katrin Kozubek, Michal Landman, Bennett A. Marz, Keno Maier, Oskar Maier-Hein, Klaus Menze, Bjoern H. Müller, Henning Neher, Peter F. Niessen, Wiro Rajpoot, Nasir Sharp, Gregory C. Sirinukunwattana, Korsuk Speidel, Stefanie Stock, Christian Stoyanov, Danail Taha, Abdel Aziz van der Sommen, Fons Wang, Ching-Wei Weber, Marc-André Zheng, Guoyan Jannin, Pierre Kopp-Schneider, Annette Heidelberg Germany Centre for Intelligent Machines McGill University MontrealQC Canada Christian Doppler Laboratory for Ophthalmic Image Analysis Department of Ophthalmology Medical University Vienna Vienna Austria Science and Engineering Faculty Queensland University of Technology BrisbaneQLD Australia Department of Electrical and Computer Engineering Department of Computer Science Johns Hopkins University Baltimore United States CISTIB Centre for Computational Imaging and Simulation Technologies in Biomedicine University of Sheffield Sheffield United Kingdom Department of Radiology and Nuclear Medicine Medical Image Analysis Radboud University Center Nijmegen Netherlands Institute of Information Systems Engineering TU Wien Vienna Austria Heidelberg University Heidelberg Germany Centre for Biomedical Image Analysis Masaryk University Brno Czech Republic Electrical Engineering Vanderbilt University NashvilleTN United States Institute of Medical Informatics Universität zu Lübeck Lübeck Germany Heidelberg Germany Institute for Advanced Studies Department of Informatics Technical University of Munich Munich Germany Information System Institute HES-SO Sierre Switzerland Departments of Radiology Nuclear Medicine and Medical Informatics Erasmus MC Rotterdam Netherlands Department of Computer Science University of Warwick Coventry United Kingdom Department of Radiation Oncology Massachusetts General Hospital BostonMA United States Institute of Biomedical Engineering University of Oxford Oxford United Kingdom National Center for Tumor Diseases Dresden Dresden Germany Heidelberg Germany Department of Computer Science University College London London United Kingdom Data Science Studio Research Studios Austria FG Vienna Austria Department of Electrical Engineering Eindhoven University of Technology Eindhoven Netherlands AIExplore NTUST Center of Computer Vision and Medical Imaging Graduate Institute of Biomedical Engineering National Ta

International challenges have become the standard for validation of biomedical image analysis methods. Given their scientific impact, it is surprising that a critical analysis of common practices related to the organization of challenges has not yet been performed. In this paper, we present a comprehensive analysis of biomedical image analysis challenges conducted up to now. We demonstrate the importance of challenges and show that the lack of quality control has critical consequences. First, reproducibility and interpretation of the results is often hampered as only a fraction of relevant information is typically provided. Second, the rank of an algorithm is generally not robust to a number of variables such as the test data used for validation, the ranking scheme applied and the observers that make the reference annotations. To overcome these problems, we recommend best practice guidelines and define open research questions to be addressed in the future. Copyright © 2018, The Authors. All rights reserved.

关键词： Quality control

Dynamic Phase Enabled Topological Mode Steering in Composite Su-Schrieffer-Heeger Waveguide Arrays

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arXiv 2024年

作者： Tang, Min Pang, Chi Saggau, Christian N. Dong, Haiyun Lee, Ching Hua Thomale, Ronny Klembt, Sebastian Fulga, Ion Cosma Van Den Brink, Jeroen Vaynzof, Yana Schmidt, Oliver G. Wang, Jiawei Ma, Libo Leibniz Institute for Solid State and Materials Research Dresden Helmholtzstraße 20 Dresden01069 Germany Key Laboratory of Photochemistry Institute of Chemistry Chinese Academy of Sciences Beijing100190 China Department of Physics National University of Singapore Singapore117551 Singapore Institut für Theoretische Physik und Astrophysik Universität Würzburg Würzburg97074 Germany Technische Physik Physikalisches Institut Wilhelm Conrad Roentgen-Research Center for Complex Material System Universität Würzburg Würzburg D-97074 Germany Institute for Theoretical Physics Technische Universität Dresden Dresden01069 Germany Technical University of Dresden Nöthnitzer Str. 61 Dresden01187 Germany TU Chemnitz Chemnitz09126 Germany TU Chemnitz Chemnitz09107 Germany School of Science TU Dresden Dresden01062 Germany School of Electronic and Information Engineering Harbin Institute of Technology Guangdong Shenzhen518055 China

Topological boundary states localize at interfaces whenever the interface implies a change of the associated topological invariant encoded in the geometric phase. The generically present dynamic phase, however, which is energy and time dependent, has been known to be non-universal, and hence not to intertwine with any topological geometric phase. Using the example of topological zero modes in composite Su-Schrieffer-Heeger (c-SSH) waveguide arrays with a central defect, we report on the selective excitation and transition of topological boundary mode based on dynamic phase-steered interferences. Our work thus provides a new knob for the control and manipulation of topological states in composite photonic devices, indicating promising applications where topological modes and their bandwidth can be jointly controlled by the dynamic phase, geometric phase, and wavelength in on-chip topological devices. Copyright © 2024, The Authors. All rights reserved.

关键词： Topology

Publisher Correction: Ozone pollution mitigation strategy informed by long-term trends of atmospheric oxidation capacity

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Nature Geoscience 2024年 172页

作者： Wenjie Wang Xin Li Ying Liu Sihua Lu Yusheng Wu Shiyi Chen Keding Lu Min Hu Limin Zeng Min Shao Yuanhang Zhang Hang Su Yafang Cheng Ruijing Ni Ulrich Pöschl Zhaofeng Tan Franz Rohrer Andreas Wahner David D. Parrish Cheng Huang Xudong Tian K. M. Leung Liangfu Chen Meng Fan Qiang Zhang State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences and Engineering Peking University Beijing China State Key Laboratory of Atmospheric Environment and Extreme Meteorology Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China Max Planck Institute for Chemistry Mainz Germany International Joint Laboratory for Regional Pollution Control Ministry of Education Beijing China Collaborative Innovation Centre of Atmospheric Environment and Equipment Technology Nanjing University of Information Science & Technology Nanjing China Institute of Carbon Neutrality Peking University Beijing China Institute for Environmental and Climate Research Jinan University Guangzhou China State Environmental Protection Key Laboratory of Formation and Prevention of Urban Air Pollution Complex Shanghai Academy of Environmental Sciences Shanghai China Institut für Energie-und Klimaforschung: Troposphäre (IEK-8) Forschungszentrum Jülich Jülich Germany Key Laboratory of Ecological and Environmental Monitoring Forewarning and Quality Control of Zhejiang Zhejiang Ecological and Environmental Monitoring Center Hangzhou China Environmental Protection Department The Government of the Hong Kong Special Administrative Region Hong Kong China State Key Laboratory of Remote Sensing Science The Aerospace Information Research Institute Chinese Academy of Sciences Beijing China Department of Earth System Science Tsinghua University Beijing China

26th Annual Computational Neuroscience Meeting (CNS*2017) of the Organization for Computational Neuroscience Antwerp, Belgium, July 15-20, 2017

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BMC NEUROscience 2017年第SUPPL 1期18卷 59-59页

作者： [Anonymous] Indiana University Purdue University Indianapolis Indianapolis IN 46032 USA Stark Neurosciences Research Institute Indiana University School of Medicine Indianapolis IN 46032 USA Department of Mathematics East Carolina University Greenville NC 27858 USA Jülich Supercomputing Centre Forschungszentrum Jülich 52425 Jülich Germany Future Systems Swiss National Supercomputing Centre 8092 Zurich Switzerland User Engagement and Support Swiss National Supercomputing Centre 6900 Lugano Switzerland Institut de Neurosciences des Systèmes Aix Marseille Univ 13005 Marseille France Simulation Lab Neuroscience Forschungszentrum Jülich Jülich Germany Department of Experimental Psychology Ghent University 9000 Ghent Belgium Donders Center for Cognitive Neuroimaging Radboud University 6525HR Nijmegen The Netherlands Department of Electrical Computer and Energy Engineering University of Colorado Boulder CO 80309 USA Department of Neurosurgery Johns Hopkins School of Medicine Baltimore MD 21287 USA Department of Neurology Johns Hopkins School of Medicine Baltimore MD 21287 USA Department of Otolaryngology Johns Hopkins School of Medicine Baltimore MD 21287 USA INSERM U968 Paris France Sorbonne Universités UPMC University Paris 06 UMR_S 968 Institut de la Vision Paris France CNRS UMR_7210 Paris France Department of Computer Architecture and Technology University of Granada (CITIC) Granada Spain Sorbonne Universités UPMC Univ Paris 06 INSERM CNRS Institut de la Vision Paris France Department of Adaptive Machine Systems Osaka University Osaka Japan Department of Computer Science University of Cergy-Pontoise Cergy-Pontoise France Department of Physics and Astronomy College of Charleston Charleston SC 29424 USA School of Physics Faculty of Science University of Sydney Sydney NSW 2006 Australia Center of Excellence for Integrative Brain Function Australian Research Council Sydney Australia Max Planck Institute for Human Cognitive and Brain Sciences Saxony Lei

Exoplanet biosignatures: A review of remotely detectable signs of life

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arXiv 2017年

作者： Schwieterman, Edward W. Kiang, Nancy Y. Parenteau, Mary N. Harman, Chester E. DasSarma, Shiladitya Fisher, Theresa M. Arney, Giada N. Hartnett, Hilairy E. Reinhard, Christopher T. Olson, Stephanie L. Meadows, Victoria S. Cockell, Charles S. Walker, Sara I. Grenfell, John Lee Hegde, Siddharth Rugheimer, Sarah Hu, Renyu Lyons, Timothy W. Department of Earth Sciences University of California RiversideCA United States NASA Postdoctoral Program Universities Space Research Association ColumbiaMD United States NASA Astrobiology Institute Virtual Planetary Laboratory Team SeattleWA United States NASA Astrobiology Institute Alternative Earths Team RiversideCA United States Blue Marble Space Institute of Science SeattleWA United States NASA Goddard Institute for Space Studies New YorkNY United States NASA Ames Research Center Exobiology Branch Mountain ViewCA United States Department of Applied Physics and Applied Mathematics Columbia University New YorkNY United States Department of Microbiology and Immunology University of Maryland School of Medicine BaltimoreMD United States Institute of Marine and Environmental Technology University System of Maryland BaltimoreMD United States School of Earth and Space Exploration Arizona State University TempeAZ United States Planetary Systems Laboratory NASA Goddard Space Flight Center GreenbeltMD United States School of Molecular Sciences Arizona State University TempeAZ United States School of Earth and Atmospheric Sciences Georgia Institute of Technology AtlantaGA United States Astronomy Department University of Washington SeattleWA United States University of Edinburgh School of Physics and Astronomy Edinburgh United Kingdom UK Centre for Astrobiology Edinburgh United Kingdom Beyond Center for Fundamental Concepts in Science Arizona State University TempeAZ United States ASU-Santa Fe Institute Center for Biosocial Complex Systems Arizona State University TempeAZ United States Berlin Germany Carl Sagan Institute Cornell University IthacaNY United States Cornell Center for Astrophysics and Planetary Science Cornell University IthacaNY United States Department of Earth and Environmental Sciences University of St. Andrews St. Andrews United Kingdom Jet Propulsion Laboratory California Institute of Technology PasadenaCA United St

In the coming years and decades, advanced space- and ground-based observatories will allow an unprecedented opportunity to probe the atmospheres and surfaces of potentially habitable exoplanets for signatures of life. Life on Earth, through its gaseous products and reflectance and scattering properties, has left its fingerprint on the spectrum of our planet. Aided by the universality of the laws of physics and chemistry, we turn to Earth’s biosphere, both in the present and through geologic time, for analog signatures that will aid in the search for life elsewhere. Considering the insights gained from modern and ancient Earth, and the broader array of hypothetical exoplanet possibilities, we have compiled a comprehensive overview of our current understanding of potential exoplanet biosignatures, including gaseous, surface, and temporal biosignatures. We additionally survey biogenic spectral features that are well known in the specialist literature but have not yet been robustly vetted in the context of exoplanet biosignatures. We briefly review advances in assessing biosignature plausibility, including novel methods for determining chemical disequilibrium from remotely obtainable data and assessment tools for determining the minimum biomass required to maintain short-lived biogenic gases as atmospheric signatures. We focus particularly on advances made since the seminal review by Des Marais et al. The purpose of this work is not to propose new biosignature strategies, a goal left to companion articles in this series, but to review the current literature, draw meaningful connections between seemingly disparate areas, and clear the way for a path forward. Copyright © 2017, The Authors. All rights reserved.

关键词： Extrasolar planets

Corrigendum to “Utilizing 2D seismic forward modeling to constrain the seismic response and plane distribution of grain shoal reservoir in the northern slope of Central Sichuan Paleo-uplift, Sichuan Basin” [Mar. Petrol. Geol. (2023) 152/DOI: https://***/10.1016/***.2023.106228]

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Marine and Petroleum Geology 2023年 153卷

作者： Wenliang Shang Shaohua Xu Xiaogang Li Feng Liang Chen Wu Jiashu Wang Zhijun Li Yonghe Sun Yuhan Li Ming Li Zhengjian Xu Zhen Tian Chongqing Key Laboratory of Complex Oil and Gas Field Exploration and Development Chongqing University of Science and Technology Chongqing 401331 China Gas Field Development and Management Department of Petro China Southwest Oil & Gas Field Company CNPC Chengdu 610051 China State Key Laboratory of Tibetan Plateau Earth System Environment and Resources (TPESER) Institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing 100101 China Chuanzhong Division of PetroChina Southwest Oil & Gas Field Company CNPC Suining 629000 China Luliang Oilfield of PetroChina Xinjiang Oilfield Company CNPC Karamay 834000 China

Vegetation Rather than Climate Dominate the Bowen Ratio Over Terrestrial Ecosystems of China

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SSRN

SSRN 2023年

作者： Sun, Mingyu Yu, Guirui Chen, Zhi Zhu, Xianjin Zhang, Weikang Han, Lang Liu, Zhaogang Ma, Lexin Dou, Xiaojun Yao, Yuan Wang, Jilong Luo, Wenxing Lin, Yong Chen, Shiping Deng, Zhengmiao Dong, Gang Du, Hu Gao, Yanhong Gu, Fengxue Hao, Xiangxiang Hao, Yanbin He, Qihua He, Yongtao He, Jinsheng Ji, Xibin Jiang, Shicheng Jiang, Zhengde Li, Xinhu Li, Yingnian Li, Yuqiang Li, Yuzhe Liu, Ran Liu, Shaomin Luo, Weijun Mo, Xingguo Sha, Liqing Shi, Peili Song, Qinghai Sun, Dan Tan, Junlei Tang, Yakun Wang, Fei Wang, Huimin Wang, Jianlin Wei, Wenxue Wu, Jiabing Wu, Zhixiang Xin, Xiaoping Yan, Junhua Zhang, Fawei Zhang, Yangjian Zhang, Yiping Zhang, Yucui Zhao, Fenghua Zhao, Liang Zhou, Li Zhu, Jiaojun Zhu, Zhilin Institute of Surface-Earth System Science School of Earth System Science Tianjin University Tianjin300072 China Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing100101 China College of Resources and Environment University of Chinese Academy of Sciences Beijing100049 China Beijing Yanshan Earth Critical Zone National Research Station University of Chinese Academy of Sciences Beijing101408 China College of Agronomy Shenyang Agricultural University Shenyang100161 China Tianjin Bohai Rim Coastal Earth Critical Zone National Observation and Research Station Tianjin University Tianjin300072 China State Key Laboratory of Vegetation and Environmental Change Institute of Botany Chinese Academy of Sciences Beijing100093 China Key Laboratory for Agro-ecological Processes in Subtropical Region Institute of Subtropical Agriculture Chinese Academy of Sciences Changsha410125 China Shanxi University Taiyuan030006 China Northwest Institute of Eco-Environment and Resources Chinese Academy of Sciences Lanzhou730000 China Institute of Environment and Sustainable Development in Agriculture Chinese Academy of Agricultural Sciences Beijing100081 China Center for Agricultural Technology Northeast Institute of Geography and Agroecology Chinese Academy of Sciences Harbin150081 China University of Chinese Academy of Sciences Beijing100049 China Chengdu Institute of Biology Chinese Academy of Sciences Chengdu610041 China Institute of Ecology College of Urban and Environmental Sciences Key Laboratory for Earth Surface Processes the Ministry of Education Peking University Beijing100871 China State Key Laboratory of Herbage Improvement and Grassland Agro-Ecosystems College of Pastoral Agriculture Science and Technology Lanzhou University Lanzhou China School of Life Sciences Northeast Normal University Changchun130024 China Institute of Applied Ecology Chinese

Bowen ratio (β) is the ratio of sensible heat (H) to latent heat (LE), which reflected the energy balance and partitioning process between soil, vegetation, and atmosphere. Revealing the spatial patterns of β would benefit understanding the variation of energy partitioning in terrestrial ecosystems and its reciprocal relationship with environmental change. Here, we calculated β by integrating sensible and latent heat flux values from 80 flux observation sites based on eddy covariance method in ChinaFLUX to analyze the spatial pattern and dominant factors of β in China. Results showed that terrestrial ecosystems in China had an average β of 0.64±0.47, suggesting the strong regulating effect of ecosystems on the radiative warming in China. β significantly varied with ecosystem types in which desert has the highest β (2.08) while wetland showed the lowest β (0.37). β of terrestrial ecosystems in China showed a significant latitudinal pattern, increasing linearly with the increase of latitude, and showed specific patterns in forest and cropland ecosystems. However, β did not present a clear longitudinal and vertical pattern in different ecosystems except cropland. The spatial pattern of β was dominated by vegetation factors including gross primary productivity (GPP). However, the dominant role of vegetation factors varied with the climate and soil conditions, which showing that the dominant role of GPP gradually decreased from the hot and humid subtropical evergreen broad-leaved forest region to the low temperature arid temperate desert region. These findings demonstrated the spatial variation and its mechanism of terrestrial ecosystems β and provided insight into the future of vegetation mitigation of global climate change. © 2023, The Authors. All rights reserved.

关键词： Heat flux

A ring-like accretion structure in M87 connecting its black hole and jet

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arXiv 2023年

作者： Lu, Ru-Sen Asada, Keiichi Krichbaum, Thomas P. Park, Jongho Tazaki, Fumie Pu, Hung-Yi Nakamura, Masanori Lobanov, Andrei Hada, Kazuhiro Akiyama, Kazunori Kim, Jae-Young Marti-Vidal, Ivan Gómez, José L. Kawashima, Tomohisa Yuan, Feng Ros, Eduardo Alef, Walter Britzen, Silke Bremer, Michael Broderick, Avery E. Doi, Akihiro Giovannini, Gabriele Giroletti, Marcello Ho, Paul T.P. Honma, Mareki Hughes, David H. Inoue, Makoto Jiang, Wu Kino, Motoki Koyama, Shoko Lindqvist, Michael Liu, Jun Marscher, Alan P. Matsushita, Satoki Nagai, Hiroshi Rottmann, Helge Savolainen, Tuomas Schuster, Karl-Friedrich Shen, Zhi-Qiang de Vicente, Pablo Walker, R. Craig Yang, Hai Zensus, J. Anton Algaba, Juan Carlos Allardi, Alexander Bach, Uwe Berthold, Ryan Bintley, Dan Byun, Do-Young Casadio, Carolina Chang, Shu-Hao Chang, Chih-Cheng Chang, Song-Chu Chen, Chung-Chen Chen, Ming-Tang Chilson, Ryan Chuter, Tim C. Conway, John Crew, Geoffrey B. Dempsey, Jessica T. Dornbusch, Sven Faber, Aaron Friberg, Per García, Javier González Garrido, Miguel Gómez Han, Chih-Chiang Han, Kuo-Chang Hasegawa, Yutaka Herrero-Illana, Ruben Huang, Yau-De Huang, Chih-Wei L. Impellizzeri, Violette Jiang, Homin Jinchi, Hao Jung, Taehyun Kallunki, Juha Kirves, Petri Kimura, Kimihiro Koay, Jun Yi Koch, Patrick M. Kramer, Carsten Kraus, Alex Kubo, Derek Kuo, Cheng-Yu Li, Chao-Te Lin, Lupin Chun-Che Liu, Ching-Tang Liu, Kuan-Yu Lo, Wen-Ping Lu, Li-Ming MacDonald, Nicholas Martin-Cocher, Pierre Messias, Hugo Meyer-Zhao, Zheng Minter, Anthony Nair, Dhanya G. Nishioka, Hiroaki Norton, Timothy J. Nystrom, George Ogawa, Hideo Oshiro, Peter Patel, Nimesh A. Pen, Ue-Li Pidopryhora, Yurii Pradel, Nicolas Raffin, Philippe A. Rao, Ramprasad Ruiz, Ignacio Sanchez, Salvador Shaw, Paul Snow, William Sridharan, T.K. Srinivasan, Ranjani Tercero, Belén Torne, Pablo Traianou, Efthalia Wagner, Jan Walther, Craig Wei, Ta-Shun Yang, Jun Yu, Chen-Yu Shanghai Astronomical Observatory Chinese Academy of Sciences Shanghai China Key Laboratory of Radio Astronomy Chinese Academy of Sciences Nanjing China Max-Planck-Institut für Radioastronomie Bonn Germany Institute of Astronomy and Astrophysics Academia Sinica Taipei Taiwan Korea Astronomy and Space Science Institute Daejeon Korea Republic of Simulation Technology Development Department Tokyo Electron Technology Solutions Oshu Japan Mizusawa VLBI Observatory National Astronomical Observatory of Japan Oshu Japan Department of Physics National Taiwan Normal University Taipei Taiwan Center of Astronomy and Gravitation National Taiwan Normal University Taipei Taiwan Department of General Science and Education National Institute of Technology Hachinohe College Hachinohe City Japan Department of Astronomical Science The Graduate University for Advanced Studies SOKENDAI Mitaka Japan Black Hole Initiative Harvard University CambridgeMA United States Massachusetts Institute of Technology Haystack Observatory WestfordMA United States National Astronomical Observatory of Japan Mitaka Japan Department of Astronomy and Atmospheric Sciences Kyungpook National University Daegu Korea Republic of Departament d’Astronomia i Astrofísica Universitat de València Valencia Spain Observatori Astronòmic Universitat de València Valencia Spain Instituto de Astrofísica de Andalucía-CSIC Granada Spain Institute for Cosmic Ray Research The University of Tokyo Chiba Japan Key Laboratory for Research in Galaxies and Cosmology Chinese Academy of Sciences Shanghai China School of Astronomy and Space Sciences University of Chinese Academy of Sciences Beijing China Institut de Radioastronomie Millimétrique Saint Martin d’Hères France Department of Physics and Astronomy University of Waterloo WaterlooON Canada Waterloo Centre for Astrophysics University of Waterloo WaterlooON Canada Perimeter Institute for Theoretical Physics WaterlooON Canada Institute of Space and Astron

The nearby radio galaxy M87 is a prime target for studying black hole accretion and jet formation1,2. Event Horizon Telescope observations of M87 in 2017, at a wavelength of 1.3 mm, revealed a ring-like structure, which was interpreted as gravitationally lensed emission around a central black hole3. Here we report images of M87 obtained in 2018, at a wavelength of 3.5 mm, showing that the compact radio core is spatially resolved. High-resolution imaging shows a ring-like structure of 8. 4!1.1$0.5 Schwarzschild radii in diameter, approximately 50% larger than that seen at 1.3 mm. The outer edge at 3.5 mm is also larger than that at 1.3 mm. This larger and thicker ring indicates a substantial contribution from the accretion flow with absorption effects in addition to the gravitationally lensed ring-like emission. The images show that the edge–brightened jet connects to the accretion flow of the black hole. Close to the black hole, the emission profile of the jet-launching region is wider than the expected profile of a black -hole-driven jet, suggesting the possible presence of a wind associated with the accretion flow. © 2023, CC BY.

关键词： Galaxies

HRPGAN: A GAN-based Model to Generate High-resolution Remote Sensing Images

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IOP Conference Series: Earth and Environmental science 2020年第1期428卷

作者： Hai Sun Ping Wang Yifan Chang Li Qi Hailei Wang Dan Xiao Cheng Zhong Xuelian Wu Wenbo Li Bingyu Sun China Telecom Shanghai Ideal Information Industry (Group) Co. Ltd Shanghai China Department of Airborne Remote Sensing National Disaster Reduction Center of China Beijing China Institute of Technology Innovation Hefei Institute of Physical Science Chinese Academy of Sciences Hefei China The Third Research Institute of the Ministry of Public Security Shanghai China Guizhou Key Laboratory of Economics System Simulation Guizhou University of Finance and Economics Guiyang China Beijing Aerospace Flight Control Center Beijing China Institute of Intelligent Machines Chinese Academy of Sciences Hefei China

Generative adversarial networks (GAN) has been mainly used in the generation of natural images such as MNIST, CIFAR10 as well as Imagenet datasets and achieves satisfying generation results. However, GAN always fails in generating high quality high-resolution remote sensing images because remote sensing images are large in size and have various ground objects. To address this issue, a novel framework called High-Resolution PatchGAN (HRPGAN) is introduced in this paper. The structure of HRPGAN follows PatchGAN, but the batch normalization layers are removed and the ReLU activation is replaced by the SELU activation. In addition, a new loss function consisting of the adversarial loss, perceptual reconstruction loss and regularization loss is used in HRPGAN. Experiment results show that the proposed HRPGAN model generates the more diverse and lifelike images in HR remote sensing generation than Bicubic method and TGAN model.

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