检索结果-内蒙古大学图书馆

arXiv 2023年

作者： Zieba, Sebastian Kreidberg, Laura Ducrot, Elsa Gillon, Michaël Morley, Caroline Schaefer, Laura Tamburo, Patrick Koll, Daniel D.B. Lyu, Xintong Acuña, Lorena Agol, Eric Iyer, Aishwarya R. Hu, Renyu Lincowski, Andrew P. Meadows, Victoria S. Selsis, Franck Bolmont, Emeline Mandell, Avi M. Suissa, Gabrielle Max-Planck-Institut für Astronomie Königstuhl 17 HeidelbergD-69117 Germany Leiden Observatory Leiden University Niels Bohrweg 2 Leiden2333CA Netherlands Université Paris-Saclay Université Paris-Cité CEA CNRS AIM France Paris Region Fellow Marie Sklodowska-Curie Action France Astrobiology Research Unit University of Liège Allée du 6 août 19 Liège4000 Belgium Department of Astronomy University of Texas 2515 Speedway AustinTX78712 United States Department of Earth and Planetary Sciences Stanford University StanfordCA United States Department of Astronomy The Institute for Astrophysical Research Boston University 725 Commonwealth Ave. BostonMA02215 United States Department of Atmospheric and Oceanic Sciences Peking University Beijing China Aix-Marseille Université CNRS CNES Institut Origines LAM Marseille France Department of Astronomy Astrobiology Program University of Washington Box 351580 SeattleWA98195 United States NASA Nexus for Exoplanet System Science Virtual Planetary Laboratory Team University of Washington Box 351580 SeattleWA98195 United States School of Earth and Space Exploration Arizona State University 525 E. University Dr. TempeAZ85281 United States NASA FINESST Fellow United States Jet Propulsion Laboratory California Institute of Technology PasadenaCA United States Division of Geological and Planetary Sciences California Institute of Technology PasadenaCA United States Laboratoire d’astrophysique de Bordeaux Univ. Bordeaux CNRS B18N allée Geoffroy Saint-Hilaire Pessac33615 France Observatoire Astronomique Université de Genève chemin Pegasi 51 VersoixCH-1290 Switzerland Centre Vie dans l’Univers Université de Genève Geneva Switzerland NASA Goddard Space Flight Center 8800 Greenbelt Rd GreenbeltMD United States Sellers Exoplanet Environments Collaboration NASA Goddard United States

Seven rocky planets orbit the nearby dwarf star TRAPPIST-1, providing a unique opportunity to search for atmospheres on small planets outside the Solar system [1]. Thanks to the recent launch of the James Webb space Telescope (JWST), possible atmospheric constituents such as carbon dioxide (CO2) are now detectable [2, 3]. Recent JWST observations of the innermost planet TRAPPIST-1 b showed that it is most probably a bare rock without any CO2 in its atmosphere [4]. Here we report the detection of thermal emission from the dayside of TRAPPIST-1 c with the Mid-Infrared Instrument (MIRI) on JWST at 15 µm. We measure a planet-to-star flux ratio of fp/f∗ = 421 ± 94 parts per million (ppm) which corresponds to an inferred dayside brightness temperature of 380 ± 31 K. This high dayside temperature disfavours a thick, CO2-rich atmosphere on the planet. The data rule out cloud-free O2/CO2 mixtures with surface pressures ranging from 10 bar (with 10 ppm CO2) to 0.1 bar (pure CO2). A Venus-analogue atmosphere with sulfuric acid clouds is also disfavoured at 2.6σ confidence. Thinner atmospheres or bare-rock surfaces are consistent with our measured planet-to-star flux ratio. The absence of a thick, CO2-rich atmosphere on TRAPPIST-1 c suggests a relatively volatile-poor formation history, with less than 9.5+7.5−2.3 Earth oceans of water. If all planets in the system formed in the same way, this would indicate a limited reservoir of volatiles for the potentially habitable planets in the system. © 2023, CC BY.

关键词： Carbon dioxide

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ET White Paper: To Find the First Earth 2.0

arXiv

引用

arXiv 2022年

作者： Ge, Jian Zhang, Hui Zang, Weicheng Deng, Hongping Mao, Shude Xie, Ji-Wei Liu, Hui-Gen Zhou, Ji-Lin Willis, Kevin Huang, Chelsea Howell, Steve B. Feng, Fabo Zhu, Jiapeng Yao, Xinyu Liu, Beibei Aizawa, Masataka Zhu, Wei Li, Ya-Ping Ma, Bo Ye, Quanzhi Yu, Jie Xiang, Maosheng Yu, Cong Liu, Shangfei Yang, Ming Wang, Mu-Tian Shi, Xian Fang, Tong Zong, Weikai Liu, Jinzhong Zhang, Yu Zhang, Liyun El-Badry, Kareem Shen, Rongfeng Tam, Pak-Hin Thomas Hu, Zhecheng Yang, Yanlv Zou, Yuan-Chuan Wu, Jia-Li Lei, Wei-Hua Wei, Jun-Jie Wu, Xue-Feng Sun, Tian-Rui Wang, Fa-Yin Zhang, Bin-Bin Xu, Dong Yang, Yuan-Pei Li, Wen-Xiong Xiang, Dan-Feng Wang, Xiaofeng Wang, Tinggui Zhang, Bing Jia, Peng Yuan, Haibo Zhang, Jinghua Wang, Sharon Xuesong Gan, Tianjun Wang, Wei Zhao, Yinan Liu, Yujuan Chen, Yonghe Wei, Chuanxin Kang, Yanwu Yang, Baoyu Qi, Chao Liu, Xiaohua Zhang, Quan Zhu, Yuji Zhou, Dan Zhang, Congcong Yu, Yong Zhang, Yongshuai Li, Yan Tang, Zhenghong Wang, Chaoyan Wang, Fengtao Li, Wei Cheng, Pengfei Shen, Chao Li, Baopeng Pan, Yue Yang, Sen Gao, Wei Song, Zongxi Wang, Jian Zhang, Hongfei Chen, Cheng Wang, Hui Zhang, Jun Wang, Zhiyue Zeng, Feng Zheng, Zhenhao Zhu, Jie Guo, Yingfan Zhang, Yihao Li, Yudong Wen, Lin Feng, Jie Chen, Wen Chen, Kun Han, Xingbo Yang, Yingquan Wang, Haoyu Duan, Xuliang Huang, Jiangjiang Liang, Hong Bi, Shaolan Gai, Ning Ge, Zhishuai Guo, Zhao Huang, Yang Li, Gang Li, Haining Li, Tanda Lu, Yuxi Lucy Rix, Hans-Walter Shi, Jianrong Song, Fen Tang, Yanke Ting, Yuan-Sen Wu, Tao Wu, Yaqian Yang, Taozhi Yin, Qing-Zhu Gould, Andrew Lee, Chung-Uk Dong, Subo Yee, Jennifer C. Shvartzvald, Yossi Yang, Hongjing Kuang, Renkun Zhang, Jiyuan Liao, Shilong Qi, Zhaoxiang Yang, Jun Zhang, Ruisheng Jiang, Chen Ou, Jian-Wen Li, Yaguang Beck, Paul Bedding, Timothy R. Campante, Tiago L. Chaplin, William J. Christensen-Dalsgaard, Jørgen García, Rafael A. Gaulme, Patrick Gizon, Laurent Hekker, Saskia Huber, Daniel Khanna, Shourya Mathur, Savita Miglio, Andrea Mosser, Benoît Ong, J.M. Joel Shanghai Astronomical Observatory Chinese Academy of Sciences Shanghai China Tsinghua University Beijing China Nanjing University Nanjing China Sun Yat-Sen University Zhuhai China Tsung-Dao Lee Institute Shanghai Jiao Tong University Shanghai China Max Planck Institute for Solar System Research Göttingen Germany Max-Planck-Institute für Astronomie Heidelberg Germany Zhejiang University Hangzhou China University of Science and Technology of China Hefei China Taiyuan University of Technology Taiyuan China University of Maryland College ParkMD United States Boston University BostonMA United States Xinjiang Astronomical Observatory Chinese Academy of Sciences Xinjiang China Huazhong University of Science and Technology Wuhan China Purple Mountain Observatories Chinese Academy of Sciences Nanjing China Guizhou University Guiyang China National Astronomical Observatories Chinese Academy of Sciences Beijing China Yunnan University Kunming China Tel Aviv University Tel Aviv Israel Science Talent Training Center Gainesville United States Shanghai Institute of Technical Physics Chinese Academy of Sciences Shanghai China Xi'An Institute of Optics and Precision Mechanics Chinese Academy of Sciences Xi'An China Innovation Academy for Microsatellites Chinese Academy of Sciences Shanghai China Department of Astronomy The University of Geneva Versoix Switzerland University of Southern Queensland QLD Australia Research School of Astronomy & Astrophysics Australian National University ACT Australia Research School of Computer Science Australian National University ACT Australia Beijing Normal University Beijing China University of Cambridge Cambridge United Kingdom Dezhou University Dezhou China Jimei University Xiamen China Ohio State University ColumbusOH United States Korea Astronomy and Space Science Institute Daejon Korea Republic of Kavli Institute for Astronomy and Astrophysics Peking University Beijing China Center for Astrophysics Harvard

The ET mission is a wide-field and ultra-high-precision photometric survey mission being developed in China. This mission is designed to measure, for the first time, the occurrence rate and the orbital distributions of Earth-sized planets. ET consists of seven 30 cm telescopes to be launched to the Earth-Sun's L2 point. Six of these are transit telescopes with a FOV of 500 square degrees. Staring in the direction that encompasses the original Kepler field for four continuous years, this monitoring will yield tens of thousands of transiting planets, including the elusive Earth twins orbiting solar-type stars. The seventh is a 30 cm microlensing telescope that will monitor an area of 4 square degrees toward the galactic bulge. Combined with simultaneous ground-based KMTNet observations, it will measure masses of hundreds of long-period and free-floating planets. Together, the transit and the microlensing telescopes will revolutionize our understanding of terrestrial planets across a large swath of orbital distances and free space. In addition, the survey data will also facilitate studies in the fields of asteroseismology, Galactic archaeology, time-domain sciences, and black holes in binaries. © 2022, CC BY-NC-ND.

关键词： Planets

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Deep Sleep Detection Using Only Respiration

引用

Journal of beijing Institute of technology 2018年第3期27卷 459-467页

作者： Yanjun Li Xiaoying Tang Zhi Xu Key Laboratory of Convergence Medical Engineering System and Healthcare Technology the Ministry of Industry and Information TechnologySchool of Life ScienceBeijing Institute of Technology State Key Laboratory of Space Medicine Fundamentals and Application China Astronaut Research and Training Center

Although polysomnogram(PSG)is the gold standard method for the evaluation of sleep quality,it becomes very difficult to clean the residual conductive gel in the hair after collecting brain electricity in the space weightlessness *** paper explores the feasibility of detecting deep sleep by using respiratory signal *** signals of oronasal airflow and abdomen movements were analyzed on ten healthy subjects from an open-access sleep dataset,namely *** sleep segments were detected by linear support-vector machine(LSVM)with three indices,including the amplitude variability in the time domain,the energy ratio of main respiratory band in the frequency domain,and the information entropy in the time-frequency *** Cohen's Kappa coefficients were 0.43,0.41 and0.45 by general LSVM with feature vectors derived from oronasal airflow,abdomen movements and both respiration above,***,the corresponding Cohen's Kappa coefficients were0.48,0.41 and 0.49 by individual LSVM,***-based method can achieve a moderate accuracy for the detection of deep sleep,with individual LSVM a little better than the general *** this approach,detecting deep sleep automatically is attainable by respiratory signals from unconstrained and contact-free *** can be applied to the sleep monitoring for astronauts on orbit.

关键词： sleep quality sleep scoring sleep stage classification deep sleep detection time-frequency analysis

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

引用

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.

关键词：

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Input optics systems of the KAGRA detector during O3GK

arXiv

引用

arXiv 2022年

作者： Akutsu, T. Ando, M. Arai, K. Arai, Y. Araki, S. Araya, A. Aritomi, N. Asada, H. Aso, Y. Bae, S. Bae, Y. Baiotti, L. Bajpai, R. Barton, M.A. Cannon, K. Cao, Z. Capocasa, E. Chan, M. Chen, C. Chen, K. Chen, Y. Chiang, C.-I. Chu, H. Chu, Y.-K. Eguchi, S. Enomoto, Y. Flaminio, R. Fujii, Y. Fujikawa, Y. Fukunaga, M. Fukushima, M. Furuhata, T. Gao, D. Ge, G.-G. Ha, S. Hagiwara, A. Haino, S. Han, W.-B. Hasegawa, K. Hattori, K. Hayakawa, H. Hayama, K. Himemoto, Y. Hiranuma, Y. Hirata, N. Hirose, E. Hong, Z. Hsieh, B.-H. Huang, G.-Z. Huang, H.-Y. Huang, P. Huang, Y.-C. Huang, Y.-J. Hui, D.C.Y. Ide, S. Ikenoue, B. Imam, S. Inayoshi, K. Inoue, Y. Ioka, K. Ito, K. Itoh, Y. Izumi, K. Jeon, C. Jin, H.-B. Jung, K. Jung, P. Kaihotsu, K. Kajita, T. Kakizaki, M. Kamiizumi, M. Kanbara, S. Kanda, N. Kang, G. Kataoka, Y. Kawaguchi, K. Kawai, N. Kawasaki, T. Kim, C. Kim, J. Kim, J.C. Kim, W.S. Kim, Y.-M. Kimura, N. Kita, N. Kitazawa, H. Kojima, Y. Kokeyama, K. Komori, K. Kong, A.K.H. Kotake, K. Kozakai, C. Kozu, R. Kumar, R. Kume, J. Kuo, C. Kuo, H.-S. Kuromiya, Y. Kuroyanagi, S. Kusayanagi, K. Kwak, K. Lee, H.K. Lee, H.W. Lee, R. Leonardi, M. Li, K.L. Lin, L.C.-C. Lin, C.-Y. Lin, F.-K. Lin, F.-L. Lin, H.L. Liu, G.C. Luo, L.-W. Majorana, E. Marchio, M. Michimura, Y. Mio, N. Miyakawa, O. Miyamoto, A. Miyazaki, Y. Miyo, K. Miyoki, S. Mori, Y. Morisaki, S. Moriwaki, Y. Nagano, K. Nagano, S. Nakamura, K. Nakano, H. Nakano, M. Nakashima, R. Nakayama, Y. Narikawa, T. Naticchioni, L. Negishi, R. Nguyen Quynh, L. Ni, W.-T. Nishizawa, A. Nozaki, S. Obuchi, Y. Ogaki, W. Oh, J.J. Oh, K. Oh, S.H. Ohashi, M. Ohishi, N. Ohkawa, M. Ohta, H. Okutani, Y. Okutomi, K. Oohara, K. Ooi, C. Oshino, S. Otabe, S. Pan, K.-C. Pang, H. Parisi, A. Park, J. Pena Arellano, F.E. Pinto, I. Sago, N. Saito, S. Saito, Y. Sakai, K. Sakai, Y. Sakuno, Y. Sato, S. Sato, T. Gravitational Wave Science Project National Astronomical Observatory of Japan 2-21-1 Osawa Mitaka City Tokyo181-8588 Japan Advanced Technology Center National Astronomical Observatory of Japan 2-21-1 Osawa Mitaka City Tokyo181-8588 Japan Department of Physics The University of Tokyo 7-3-1 Hongo Bunkyo-ku Tokyo113-0033 Japan Research Center for the Early Universe The University of Tokyo 7-3-1 Hongo Bunkyo-ku Tokyo113-0033 Japan Institute for Cosmic Ray Research KAGRA Observatory The University of Tokyo 5-1-5 Kashiwa-no-Ha Kashiwa City Chiba277-8582 Japan 1-1 Oho Tsukuba City Ibaraki305-0801 Japan Earthquake Research Institute The University of Tokyo 1-1-1 Yayoi Bunkyo-ku Tokyo113-0032 Japan Department of Mathematics and Physics Graduate School of Science and Technology Hirosaki University 3 Bunkyo-cho Aomori Hirosaki036-8561 Japan Kamioka Branch National Astronomical Observatory of Japan 238 Higashi-Mozumi Kamioka-cho Gifu Hida City506-1205 Japan 2-21-1 Osawa Mitaka City Tokyo181-8588 Japan Korea Institute of Science and Technology Information 245 Daehak-ro Yuseong-gu Daejeon34141 Korea Republic of National Institute for Mathematical Sciences 70 Yuseong-daero 1689 Beon-gil Yuseong-gu Daejeon34047 Korea Republic of International College Osaka University 1-1 Machikaneyama-cho Toyonaka City Osaka560-0043 Japan 1-1 Oho Tsukuba City Ibaraki305-0801 Japan Department of Astronomy Beijing Normal University Xinjiekouwai Street 19 Haidian District Beijing100875 China Department of Applied Physics Fukuoka University 8-19-1 Nanakuma Jonan Fukuoka Fukuoka City814-0180 Japan Department of Physics Tamkang University No. 151 Yingzhuan Rd. Danshui Dist. New Taipei City25137 Taiwan Department of Physics Institute of Astronomy National Tsing Hua University No. 101 Section 2 Kuang-Fu Road Hsinchu30013 Taiwan Department of Physics Center for High Energy and High Field Physics National Central University No.300 Zhongda

KAGRA, the underground and cryogenic gravitational-wave detector, was operated for its solo observation from February 25th to March 10th, 2020, and its first joint observation with the GEO 600 detector from April 7th - 21st, 2020 (O3GK). This study presents an overview of the input optics systems of the KAGRA detector, which consist of various optical systems, such as a laser source, its intensity and frequency stabilization systems, modulators, a Faraday isolator, mode-matching telescopes, and a high-power beam dump. These optics were successfully delivered to the KAGRA interferometer and operated stably during the observations. The laser frequency noise was observed to limit the detector sensitivity above a few kHz, whereas the laser intensity did not significantly limit the detector sensitivity. © 2022, CC BY.

关键词： Gravity waves

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The tianQin project: Current progress on science and technology

arXiv

引用

arXiv 2020年

作者： Mei, Jianwei Bai, Yan-Zheng Bao, Jiahui Barausse, Enrico Cai, Lin Canuto, Enrico Cao, Bin Chen, Wei-Ming Chen, Yu Ding, Yan-Wei Duan, Hui-Zong Fan, Huimin Feng, Wen-Fan Fu, Honglin Gao, Qing Gao, TianQuan Gong, Yungui Gou, Xingyu Gu, Chao-Zheng Gu, De-Feng He, Zi-Qi Hendry, Martin Hong, Wei Hu, Xin-Chun Hu, Yi-Ming Hu, Yuexin Huang, Shun-Jia Huang, Xiang-Qing Jiang, Qinghua Jiang, Yuan-Ze Jiang, Yun Jiang, Zhen Jin, Hong-Ming Korol, Valeriya Li, Hong-Yin Li, Ming Li, Ming Li, Pengcheng Li, Rongwang Li, Yuqiang Li, Zhu Li, Zhulian Li, Zhu-Xi Liang, Yu-Rong Liang, Zheng-Cheng Liao, Fang-Jie Liu, Shuai Liu, Yan-Chong Liu, Li Liu, Pei-Bo Liu, Xuhui Liu, Yuan Lu, Xiong-Fei Lu, Yang Lu, Ze-Huang Luo, Yan Luo, Zhi-Cai Milyukov, Vadim Ming, Min Pi, Xiaoyu Qin, Chenggang Qu, Shao-Bo Sesana, Alberto Shao, Chenggang Shi, Changfu Su, Wei Tan, Ding-Yin Tan, Yujie Tan, Zhuangbin Tu, Liang-Cheng Wang, Bin Wang, Cheng-Rui Wang, Fengbin Wang, Guan-Fang Wang, Haitian Wang, Jian Wang, Lijiao Wang, Panpan Wang, Xudong Wang, Yan Wang, Yi-Fan Wei, Ran Wu, Shu-Chao Xiao, Chun-Yu Xu, Xiao-Shi Xue, Chao Yang, Fang-Chao Yang, Liang Yang, Ming-Lin Yang, Shan-Qing Ye, Bobing Yeh, Hsien-Chi Yu, Shenghua Zhai, Dongsheng Zhang, Caishi Zhang, Haitao Zhang, Jian-Dong Zhang, Jie Zhang, Lihua Zhang, Xin Zhang, Xuefeng Zhou, Hao Zhou, Ming-Yue Zhou, Ze-Bing Zhu, Dong-Dong Zi, Tie-Guang Luo, Jun Zhuhai519082 China Centre for Gravitational Experiments School of Physics MOE Key Laboratory of Fundamental Physical Quantities Measurement Hubei Key Laboratory of Gravitation and Quantum Physics PGMF Huazhong University of Science and Technology Wuhan430074 China DFH Satellite Co. Ltd. Beijing100094 China Yunnan Observatories Chinese Academy of Sciences Kunming650011 China Beijing Institute of Control Engineering Beijing100094 China Beijing Institute of Spacecraft System Engineering Beijing100094 China SISSA Via Bonomea 265 Trieste34136 Italy INFN Sezione di Trieste IFPU - Institute for Fundamental Physics of the Universe Via Beirut 2 Trieste34014 Italy Former Faculty Politecnico di Torino Corso Duca degli Abruzzi 24 Torino10129 Italy School of Physical Science and Technology Southwest University Chongqing400715 China SUPA School of Physics and Astronomy University of Glasgow GlasgowG12 8QQ United Kingdom National Astronomical Observatories Chinese Academy of Sciences Beijing100012 China School of Astronomy and Space Science University of Chinese Academy of Sciences Beijing100049 China School of Physics and Astronomy University of Birmingham BirminghamB15 2TT United Kingdom Center for High Energy Physics Department of Physics State Key Laboratory of Nuclear Physics and Technology Peking University No.5 Yiheyuan Rd Beijing100871 China Lomonosov Moscow State University Sternberg Astronomical Institute Moscow119992 Russia Dipartimento di Fisica "G. Occhialini" Universitá degli Studi Milano Bicocca Piazza della Scienza 3 MilanoI-20126 Italy School of Aeronautics and Astronautics Shanghai Jiao Tong University Shanghai200240 China Purple Mountain Observatory Chinese Academy of Sciences Nanjing210023 China School of Astronomy and Space Science University of Science and Technology of China HefeiAnhui230026 China HannoverD-30167 Germany Leibniz Universität Hannover HannoverD-30167 Germany Department of Physics College of Sci

TianQin is a planned space-based gravitational wave (GW) observatory consisting of three earth orbiting satellites with an orbital radius of about 105 km. The satellites will form a equilateral triangle constellation the plane of which is nearly perpendicular to the ecliptic plane. TianQin aims to detect GWs between 10−4 Hz and 1 Hz that can be generated by a wide variety of important astrophysical and cosmological sources, including the inspiral of Galactic ultra-compact binaries, the inspiral of stellar-mass black hole binaries, extreme mass ratio inspirals, the merger of massive black hole binaries, and possibly the energetic processes in the very early universe or exotic sources such as cosmic strings. In order to start science operations around 2035, a roadmap called the 0123 plan is being used to bring the key technologies of TianQin to maturity, supported by the construction of a series of research facilities on the ground. Two major projects of the 0123 plan are being carried out. In this process, the team has created a new generation 17 cm single-body hollow corner-cube retro-reflector which has been launched with the QueQiao satellite on 21 May 2018;a new laser ranging station equipped with a 1.2 m telescope has been constructed and the station has successfully ranged to all the five retro-reflectors on the Moon;and the TianQin-1 experimental satellite has been launched on 20 December 2019 and the first round result shows that the satellite has exceeded all of its mission requirements. Copyright © 2020, The Authors. All rights reserved.

关键词： Orbits

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Ozone and secondary organic aerosol formation potential from anthropogenic volatile organic compounds emissions in China

引用

Journal of Environmental sciences 2017年第3期29卷 224-237页

作者： WenJing Wu Bin Zhao Shuxiao Wang Jiming Hao State Key Joint Laboratory of Environment Simulation and Pollution Control School of EnvironmentTsinghua UniversityBeijing 100084China State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex Beijing 100084China Collaborative Innovation Center for Regional Environmental Quality Tsinghua UniversityBeijin9 100084China Joint Institute for Earth System Science and Engineering Department of Atmospheric and Oceanic SciencesUniversity of CaliforniaLos AngelesCA 90095USA.

Volatile organic compounds （VOCs） are major precursors for ozone and secondary organic aerosol （SOA）, both of which greatly harm human health and significantly affect the Earth＇s climate. We simultaneously estimated ozone and SOA formation from anthropogenic VOCs emissions in China by employing photochemical ozone creation potential （POCP） values and SOA yields. We gave special attention to large molecular species and adopted the SOA yield curves from latest smog chamber experiments. The estimation shows that alkylbenzenes are greatest contributors to both ozone and SOA formation （36.0% and 51.6%, respectively）, while toluene and xylenes are largest contributing individual VOCs. Industry solvent use, industry process and domestic combustion are three sectors with the largest contributions to both ozone （24.7%, 23.0% and 17.8%, respectively） and SOA （22.9%, 34.6% and 19.6%, respectively） formation. In terms of the formation potential per unit VOCs emission, ozone is sensitive to open biomass burning, transportation, and domestic solvent use, and SOA is sensitive to industry process, domestic solvent use, and domestic combustion. Biomass stoves, paint application in industrial protection and buildings, adhesives application are key individual sources to ozone and SOA formation, whether measured by total contribution or contribution per unit VOCs emission. The results imply that current VOCs control policies should be extended to cover most important industrial sources, and the control measures for biomass stoves should be tightened. Finally, discrepant VOCs control policies should be implemented in different regions based on their ozone/aerosol concentration levels and dominant emission sources for ozone and SOA formation potential.

关键词： Volatile organic compounds （VOCs）OzoneSecondary organic aerosol （SOA）Formation potentialControl strategy

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Three low-mass companions around aged stars discovered by TESS

arXiv

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arXiv 2022年

作者： Lin, Zitao Gan, Tianjun Wang, Sharon X. Shporer, Avi Rabus, Markus Zhou, George Psaridi, Angelica Bouchy, François Bieryla, Allyson Latham, David W. Mao, Shude Stassun, Keivan G. Hellier, Coel Howell, Steve B. Ziegler, Carl Caldwell, Douglas A. Clark, Catherine A. Collins, Karen A. Curtis, Jason L. Faherty, Jacqueline K. Gnilka, Crystal L. Grunblatt, Samuel K. Jenkins, Jon M. Johnson, Marshall C. Law, Nicholas Lendl, Monika Littlefield, Colin Lund, Michael B. Lund, Mikkel N. Mann, Andrew W. McDermott, Scott Mishra, Lokesh Mounzer, Dany Paegert, Martin Pritchard, Tyler Ricker, George R. Seager, Sara Srdoc, Gregor Sun, Qinghui Tang, Jiaxin Udry, Stéphane Vanderspek, Roland Watanabe, David Winn, Joshua N. Yu, Jie Department of Astronomy Tsinghua University Beijing100084 China Department of Physics Kavli Institute for Astrophysics and Space Research Massachusetts Institute of Technology CambridgeMA02139 United States Departamento de Matemática y Física Aplicadas Facultad de Ingeniería Universidad Católica de la Santísima Concepción Alonso de Rivera Concepción2850 Chile Centre for Astrophysics University of Southern Queensland West Street ToowoombaQLD4350 Australia Observatoire de Genève Université de Genève Chemin Pegasi 51 Versoix1290 Switzerland Center for Astrophysics Harvard & Smithsonian 60 Garden Street CambridgeMA02138 United States National Astronomical Observatories Chinese Academy of Sciences 20A Datun Road Chaoyang District Beijing100012 China Department of Physics and Astronomy Vanderbilt University NashvilleTN37235 United States Astrophysics Group Keele University StaffordshireST5 5BG United Kingdom NASA Ames Research Center Moffett FieldCA94035 United States Department of Physics Engineering and Astronomy Stephen F. Austin State University 1936 North St NacogdochesTX75962 United States SETI Institute Mountain ViewCA94043 United States Jet Propulsion Laboratory California Institute of Technology PasadenaCA91109 United States NASA Exoplanet Science Institute IPAC California Institute of Technology PasadenaCA91125 United States Department of Astronomy Columbia University 550 West 120th Street New YorkNY United States Department of Astrophysics American Museum of Natural History Central Park West at 79th St. New YorkNY10024 United States Department of Physics and Astronomy Johns Hopkins University 3400 N Charles St BaltimoreMD21218 United States Department of Astronomy The Ohio State University 4055 McPherson Laboratory 140 West 18th Avenue ColumbusOH43210 United States Department of Physics and Astronomy The University of North Carolina at Chapel Hill Chapel HillNC27599-3255 United States Bay Area Environmenta

We report the discovery of three transiting low-mass companions to aged stars: a brown dwarf (TOI-2336b) and two objects near the hydrogen burning mass limit (TOI-1608b and TOI-2521b). These three systems were first identified using data from the Transiting Exoplanet Survey Satellite (TESS). TOI-2336b has a radius of 1.05 ± 0.04 RJ, a mass of 69.9 ± 2.3 MJ and an orbital period of 7.71 days. TOI-1608b has a radius of 1.21 ± 0.06 RJ, a mass of 90.7 ± 3.7 MJ and an orbital period of 2.47 days. TOI-2521b has a radius of 1.01 ± 0.04 RJ, a mass of 77.5 ± 3.3 MJ and an orbital period of 5.56 days. We found all these low-mass companions are inflated. We fitted a relation between radius, mass and incident flux using the sample of known transiting brown dwarfs and low-mass M dwarfs. We found a positive correlation between the flux and the radius for brown dwarfs and for low-mass stars that is weaker than the correlation observed for giant planets. We also found that TOI-1608 and TOI-2521 are very likely to be spin-orbit synchronized, leading to the unusually rapid rotation of the primary stars considering their evolutionary stages. Our estimates indicate that both systems have much shorter spin-orbit synchronization timescales compared to their ages. These systems provide valuable insights into the evolution of stellar systems with brown dwarf and low-mass stellar companions influenced by tidal effects. © 2022, CC BY.

关键词： Orbits

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An intrinsic approach to formation control of regular polyhedra for reduced attitudes

arXiv

引用

arXiv 2018年

作者： Zhang, Silun He, Fenghua Hong, Yiguang Hu, Xiaoming Optimization and Systems Theory Department of Mathematics KTH Royal Institute of Technology Stockholm100 44 Sweden Control and Simulation Center Harbin Institute of Technology Harbin150001 China Key Laboratory of Systems and Control Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing100190 China

This paper addresses formation control of reduced attitudes in which a continuous control protocol is proposed for achieving and stabilizing all regular polyhedra (also known as Platonic solids) under a unified framework. The protocol contains only relative reduced attitude measurements and does not depend on any particular parametrization as is usually used in the literature. A key feature of the control proposed is that it is intrinsic in the sense that it does not need to incorporate any information of the desired formation. Instead, the achieved formation pattern is totally attributed to the geometric properties of the space and the designed inter-agent connection topology. Using a novel coordinates transformation, asymptotic stability of the desired formations is proven by studying stability of a constrained nonlinear system. In addition, a methodology to investigate stability of such constrained systems is also presented. Copyright © 2018, The Authors. All rights reserved.

关键词： Attitude control

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The Research of Low Earth Orbit Prediction of Satellite Based on Deep Neural Network

The Research of Low Earth Orbit Prediction of Satellite Base...

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2017 2nd International Conference on Computer, Mechatronics and Electronic Engineering(CMEE 2017)

作者： Hai-tao YANG Jun-peng ZHU Jian ZHANG Science and Technology on Complex Electronic System Simulation Laboratory Space Engineering University Department of Graduate Management Space Engineering University

Satellite orbit prediction is a basic requirement in satellite applications. The current orbit prediction mainly depends on the dynamic model. Because of the limitations of the detection equipment and the satellite orbit data cannot be updated in time, which cause the dynamical model long-term orbit divergence to be serious. Using deep neural network as a method of orbit prediction which can predict the future data by training the satellite orbit data and grasp the implicit relationship between the data. The neural network model is optimized and the prediction data is compared with the actual data. The error of 20 days forecast is reduced to 2 km, which improves the accuracy of neural network forecasting satellite orbit.

关键词： Satellite orbit prediction Deep neural network

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