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ACS ES&T air 2024年第4期1卷 283-293页

作者： Xuan Liu Jay R Turner Christopher R Oxford Jacob McNeill Brenna Walsh Emmie Le Roy Crystal L Weagle Emily Stone Haihui Zhu Wenyu Liu Zilin Wei Nicole P Hyslop Jason Giacomo Ann M Dillner Abdus Salam Al-Amin Hossen Zubayer Islam Ihab Abboud Clement Akoshile Omar Amador-Muñoz Nguyen Xuan Anh Araya Asfaw Rajasekhar Balasubramanian Rachel Ying-Wen Chang Craig Coburn Sagnik Dey David J Diner Jinlu Dong Tareq Farrah Paterne Gahungu Rebecca M Garland Michel Grutter de la Mora Sina Hasheminassab Juanette John Jhoon Kim Jong Sung Kim Kristy Langerman Pei-Chen Lee Puji Lestari Yang Liu Tesfaye Mamo Mathieu Martins Olga L Mayol-Bracero Mogesh Naidoo Sang Seo Park Yoav Schechner Robyn Schofield Sachchida N Tripathi Eli Windwer Ming-Tsang Wu Qiang Zhang Michael Brauer Yinon Rudich Randall V Martin Department of Energy Environmental & Chemical Engineering Washington University in St. Louis St. Louis Missouri 63130 United States. Air Quality Research Center University of California Davis Davis California 95616 United States. Department of Chemistry University of Dhaka Dhaka 1000 Bangladesh. Air Quality Research Division Environment and Climate Change Canada Toronto Ontario M3H 5T4 Canada. Department of Physics University of Ilorin Ilorin 240003 Nigeria. Instituto de Ciencias de la Atmósfera y Cambio Climático Universidad Nacional Autónoma de México Mexico City 04510 Mexico. Institute of Geophysics Vietnam Academy of Science and Technology Hanoi 11307 Vietnam. Institute of Geophysics and Space Science Addis Ababa University Addis Ababa 1176 Ethiopia. Department of Civil and Environmental Engineering National University of Singapore Singapore 117576 Singapore. Department of Physics and Atmospheric Science Dalhousie University Halifax Nova Scotia B3H 4R2 Canada. Department of Geography and Environment University of Lethbridge Lethbridge Alberta T1K 3M4 Canada. Centre for Atmospheric Sciences Indian Institute of Technology Delhi New Delhi 110016 India. Jet Propulsion Laboratory California Institute of Technology Pasadena California 91109 United States. School of Environment Tsinghua University Beijing 100084 People's Republic of China. Research Laboratories Khalifa University Abu Dhabi 127788 United Arab Emirates. Institute of Applied Statistics University of Burundi Bujumbura BP1550 Burundi. Council for Scientific and Industrial Research Pretoria 0001 South Africa. Unit for Environmental Sciences and Management North-West University Potchefstroom 2531 South Africa. Department of Geography Geo-Informatics and Meteorology University of Pretoria Pretoria 0002 South Africa. Department of Atmospheric Sciences Yonsei University Seoul 03722 Republic of Korea. Department of Community Health and Epidemiology Dalhousie University Halifax Nova Scotia B3

Global ground-level measurements of elements in ambient particulate matter (PM) can provide valuable information to understand the distribution of dust and trace elements, assess health impacts, and investigate emission sources. We use X-ray fluorescence spectroscopy to characterize the elemental composition of PM samples collected from 27 globally distributed sites in the Surface PARTiculate mAtter Network (SPARTAN) over 2019-2023. Consistent protocols are applied to collect all samples and analyze them at one central laboratory, which facilitates comparison across different sites. Multiple quality assurance measures are performed, including applying reference materials that resemble typical PM samples, acceptance testing, and routine quality control. Method detection limits and uncertainties are estimated. Concentrations of dust and trace element oxides (TEO) are determined from the elemental dataset. In addition to sites in arid regions, a moderately high mean dust concentration (6 μg/m) in PM is also found in Dhaka (Bangladesh) along with a high average TEO level (6 μg/m). High carcinogenic risk (>1 cancer case per 100000 adults) from airborne arsenic is observed in Dhaka (Bangladesh), Kanpur (India), and Hanoi (Vietnam). Industries of informal lead-acid battery and e-waste recycling as well as coal-fired brick kilns likely contribute to the elevated trace element concentrations found in Dhaka.

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Evaluating CMIP6 Model Accuracy in Predicting and Clustering Precipitation and Temperature Trends in the Omo-Gibe River Basin, Ethiopia

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Atmosphere 2025年第1期63卷

作者： Fetene Muluken Chanie Mulugeta Genanu Kebede Yared Godine Demeke Zelalem K. Bedaso Assefa Derbew Tegen Eyale Bayable 1 Department of Meteorological Data and Climatology Ethiopian Meteorology Institute Addis Ababa Ethiopia3 Meteorology and Hydrology Faculty Water Technology Institute Arba Minch University Arba Minch Ethiopia 2 Institute of Geophysics Space Science and Astronomy Atmospheric and Oceanic Sciences Unit Addis Ababa University Addis Ababa Ethiopia5 State Key Laboratory of Tibetan Plateau Earth System Resources and Environment Institute of Tibetan Plateau Research Chinese Academy of Sciences and University of Chinese Academy of Sciences Beijing People’s Republic of China 3 Meteorology and Hydrology Faculty Water Technology Institute Arba Minch University Arba Minch Ethiopia 4 Department of Geology and Environmental Geosciences University of Dayton 300 College Park Dayton OH45469-2364 USA 5 State Key Laboratory of Tibetan Plateau Earth System Resources and Environment Institute of Tibetan Plateau Research Chinese Academy of Sciences and University of Chinese Academy of Sciences Beijing People’s Republic of China6 Federal TVT Institute Faculty of Civil Technology Department of Water Works Construction Addis Ababa 190310 Ethiopia 7 Addis Ababa University College of Natural and Computational Sciences Center for Environmental Science Addis Ababa1176 Ethiopia

ABSTRACTThis study evaluated the performance of the latest generation of global climate models (CMIP6) in predicting and clustering climate variables in the Omo-Gibe River Basin (OGRB), Ethiopia—a region highly vulnerable to climate change. Historical data (1984–2014) were used to evaluate 12 CMIP6 models using statistical metrics (R², RMSE, MBE) and categorical metrics (POD, FAR, CSI), identifying the best-performing models for each cluster. The selected models underwent bias correction using distribution mapping to enhance projection accuracy under two socio-economic pathways: SSP2–4.5 (moderate emissions) and SSP5–8.5 (high emissions) for the near-term (2023–2053) and mid-term (2054–2084) periods. The study employed the K-means clustering method to classify spatial variations in precipitation and temperature, resulting in three clusters of precipitation and two clusters for temperature. Sen's slope estimator and the Modified Mann-Kendall (MMK) test were utilized to analyze trends in precipitation and temperature time series. Key findings include model performance: For precipitation, INM-CM5-0, FGOALS-g3, and IPSL-CM6A-LR demonstrated strong performance in Clusters 1 and 3, while MPI-ESM1-2-LR and NorESM2-MM excelled in Cluster 2. For temperature, INM-CM5-0, BCC-CSM2-MR, and MPI-ESM1-2-LR exhibited the highest accuracy in Clusters 1 and 2. Significant precipitation increases were noted, particularly in Cluster 3, which shows a 74.7% rise by mid-century under SSP5–8.5. Temperature projections indicate maximum increases of 11.5% (absolute change: 3.1°C) in Cluster 1 and 8.4% (absolute change: 2.2°C) in Cluster 2, while minimum temperature rises reach as high as 23.5% (absolute change: 3.5°C). Spatial clustering revealed distinct climate patterns, with regions experiencing monomodal and bimodal rainfall cycles, providing a nuanced understanding of precipitation and temperature dynamics across the basin. These results reveal pronounced shifts in climate patterns, unde

关键词： Climate Change CMIP6 model climate projections Omo-Gibe River Basin

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Anisotropic flow in fixed-target 208Pb+20Ne collisions as a probe of quark-gluon plasma

arXiv

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arXiv 2024年

作者： Giacalone, Giuliano Zhao, Wenbin Bally, Benjamin Shen, Shihang Duguet, Thomas Ebran, Jean-Paul Elhatisari, Serdar Frosini, Mikael Lähde, Timo A. Lee, Dean Lu, Bing-Nan Ma, Yuan-Zhuo Meißner, Ulf G. Nijs, Govert Noronha-Hostler, Jacquelyn Plumberg, Christopher Rodríguez, Tomás R. Roth, Robert van der Schee, Wilke Schenke, Björn Shen, Chun Somà, Vittorio Institut für Theoretische Physik Universität Heidelberg Philosophenweg 16 Heidelberg69120 Germany Nuclear Science Division Lawrence Berkeley National Laboratory BerkeleyCA94720 United States Physics Department University of California BerkeleyCA94720 United States ESNT IRFU CEA Université Paris-Saclay Gif-sur-Yvette91191 France Forschungszentrum Jülich JülichD-52425 Germany IRFU CEA Université Paris-Saclay Gif-sur-Yvette91191 France KU Leuven Instituut voor Kern- en Stralingsfysica Leuven3001 Belgium CEA DAM DIF Arpajon91297 France Université Paris-Saclay CEA Laboratoire Matière en Conditions Extrêmes Bruyères-le-Châtel91680 France Faculty of Natural Sciences and Engineering Gaziantep Islam Science and Technology University Gaziantep27010 Turkey CEA DES IRESNE DER SPRC LEPh Saint-Paul-lez-Durance13115 France Institut für Kernphysik Institute for Advanced Simulation Jülich Center for Hadron Physics Forschungszentrum Julich JülichD-52425 Germany Forschungszentrum Julich JülichD-52425 Germany Facility for Rare Isotope Beams Department of Physics and Astronomy Michigan State University MI48824 United States Graduate School of China Academy of Engineering Physics Beijing100193 China Helmholtz-Institut für Strahlen- und Kernphysik Universität Bonn BonnD-53115 Germany Bethe Center for Theoretical Physics Universität Bonn BonnD-53115 Germany Theoretical Physics Department CERN Genève 23CH-1211 Switzerland Illinois Center for Advanced Studies of the Universe Department of Physics University of Illinois at Urbana-Champaign UrbanaIL61801 United States Natural Science Division Pepperdine University MalibuCA90263 United States Departamento de Estructura de la Materia Física Térmica y Electrónica and IPARCOS Universidad Complutense de Madrid MadridE-28040 Spain Institut für Kernphysik Technische Universität Darmstadt Darmstadt64289 Germany Helmholtz Forschungsakademie Hessen für FAIR GSI Helmholtzzentrum Darmstadt6428

The system for Measuring Overlap with Gas (SMOG2) at the LHCb detector enables the study of fixed-target ion-ion collisions at relativistic energies (√sNN ∼ 100 GeV in the centre-of-mass). With input from ab initio calculations of the structure of 16O and 20Ne, we compute 3+1D hydrodynamic predictions for the anisotropic flow of Pb+Ne and Pb+O collisions, to be tested with upcoming LHCb data. This will allow the detailed study of quark-gluon plasma (QGP) formation as well as experimental tests of the predicted nuclear shapes. Elliptic flow (v2) in Pb+Ne collisions is greatly enhanced compared to the Pb+O baseline due to the shape of 20Ne, which is deformed in a bowling-pin geometry. Owing to the large 208Pb radius, this effect is seen in a broad centrality range, a unique feature of this collision configuration. Larger elliptic flow further enhances the quadrangular flow (v4) of Pb+Ne collisions via non-linear coupling, and impacts the sign of the kurtosis of the elliptic flow vector distribution (c2{4}). Exploiting the shape of 20Ne proves thus an ideal method to investigate the formation of QGP in fixed-target experiments at LHCb, and demonstrates the power of SMOG2 as a tool to image nuclear ground states. © 2024, CC BY.

关键词： Anisotropy

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Differential Phase Processing and Data Quality Control for Polarimetric Weather Radar in Southern China

Differential Phase Processing and Data Quality Control for P...

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Progress in Electromagnetic Research Symposium (PIERS)

作者： Qiulei Xia Haonan Chen Jieying He Wenjuan Zhang Zhendong Yao College of Electronic Engineering Chengdu University of Information Technology Chengdu China NOAA/Earth System Research Laboratory and Colorado State University Colorado USA Key Laboratory of Microwave Remote Sensing National Space Science Center Beijing China State Key Laboratory of Severe Weather Chinese Academy of Meteorological Sciences Beijing China

ISBN: (数字)9781728134031

ISBN: (纸本)9781728134048

Compared to traditional single-polarization radar, dual-polarization radar transmits both horizontally and vertically polarized electromagnetic waves, and can measure not only returned power (i.e., reflectivity Zh) but also polarimetric variables including differential reflectivity Zdr, correlation coefficient ρhv, and differential propagation phase ψdp. Among the advantages of polarimetric observables for hydrometeor classification and quantification, data quality control is a main driver for the operational implementation of dual-polarization technique. This paper implements an adaptive algorithm for differential phase processing and data quality control for S-band radar measurements in southern China. In particular, phase unfolding, range filtering, and polynomial regression are employed in the phase processing. Combined with the properties of ρhv, a data quality control procedure is developed to mitigate ground clutter and non-meteorological echoes. The performance is demonstrated through cross-comparison with polarimetric radar moments simulated using raindrop size distribution (DSD) data.

关键词： Data integrity Meteorological radar Springs Radar polarimetry Tropical cyclones Radar measurements

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Polarimetric Radar-based Quantitative Precipitation Estimation during Typhoon Events over Southern China

Polarimetric Radar-based Quantitative Precipitation Estimati...

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IEEE International Geoscience and Remote Sensing Symposium

作者： Qiulei Xia Haonan Chen Wenjuan Zhang Jieying He Zhendong Yao College of Electronic Engineering Chengdu University of Information Technology Chengdu China NOAA/Earth System Research Laboratory and Colorado State University Colorado State Key Laboratory of Severe Weather Chinese Academy of Meteorological Sciences Beijing China Key Laboratory of Microwave Remote Sensing National Space Science Center Beijing China

Typhoon is often accompanied by strong convective weather such as high winds and heavy rainfall. The dual-polarization radar observations show a great performance for quantitative precipitation estimation (QPE) over traditional single-polarization radar by gleaning more useful information about precipitation particle size and shape distributions. According to the simulation of raindrop size distribution data from disdrometers in Guangzhou, China, this paper established a localized QPE algorithm for three typhoons landing in southern China. This regional QPE algorithm was compared with various rainfall relations such as the default Z-R relationship (Z = 300R~(1.4)) adopted by the WSR-88D. Results show that the rainfall estimates with localized algorithms approximate to rainfall observations from surface meteorological stations. The localized QPE algorithm is more accurate and reliable than other algorithms for typhoon events over southern China.

关键词： Tropical cyclones Radar polarimetry Meteorological radar Estimation Approximation algorithms Meteorology

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COVID-19 causes record decline in global CO2 emissions

arXiv

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arXiv 2020年

作者： Liu, Zhu Ciais, Philippe Deng, Zhu Lei, Ruixue Davis, Steven J. Feng, Sha Zheng, Bo Cui, Duo Dou, Xinyu He, Pan Zhu, Biqing Lu, Chenxi Ke, Piyu Sun, Taochun Wang, Yuan Yue, Xu Wang, Yilong Lei, Yadong Zhou, Hao Cai, Zhaonan Wu, Yuhui Guo, Runtao Han, Tingxuan Xue, Jinjun Boucher, Olivier Boucher, Eulalie Chevallier, Frederic Wei, Yimin Zhong, Haiwang Kang, Chongqing Zhang, Ning Chen, Bin Xi, Fengming Marie, François Zhang, Qiang Guan, Dabo Gong, Peng Kammen, Daniel M. He, Kebin Schellnhuber, Hans Joachim Department of EarthSystem Science Tsinghua University Beijing100084 China Laboratoire des Sciences du Climate et de l'Environnement LSCE Orme de Merisiers Gif-sur-Yvette91191 France Department of Meteorology andAtmospheric Science The Pennsylvania State University University ParkPA16802 United States Department of Earth System Science University of California Irvine 3232 Croul Hall IrvineCA92697-3100 United States Division of Geological and Planetary Sciences California Institute of Technology PasadenaCA United States Jet Propulsion Laboratory California Institute of Technology PasadenaCA United States Nanjing210044 China Key Laboratory of Land Surface Pattern and Simulation Institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences Beijing China Climate Change Research Center Institute of Atmospheric Physics Chinese Academy of Sciences Beijing100029 China Key Laboratory of Middle Atmosphere and Global Environment Observation Institute of Atmospheric Physics Chinese Academy of Sciences Beijing100029 China School of Environment Tsinghua University Beijing100084 China School of Mat hemat ical School T singhua University Beijing100084 China Department of Mathematical Sciences Tsinghua University Beijing100084 China Center of Hubei Cooperative Innovation for Emissions Trading System Wuhan China Faculty of Management and Economics Kunming University of Science and Technology 13 Kunming China Economic Research Centre of Nagoya University Furo-cho Chikusa-ku Nagoya Japan Institute Pierre-Simon Laplace Sorbonne Université CNRS Paris France Center for Energy and Environmental Policy Research Beijing Institute of Technology Beijing China Department of Electrical Engineering Tsinghua University Beijing100084 China Jinan University Guangzhou China Beijing Normal University Beijing China Institute of Applied Ecology Chinese Academy of Sciences Shenyang China Energy and Resources Group Goldman School of Pub

The considerable cessation of human activities during the COVID-19 pandemic has affected global energy use and CO2 emissions. Here we show the unprecedented decrease in global fossil CO2 emissions from January to April 2020 was of 7.8% (938 Mt CO2 with a +6.8% of 2-σ uncertainty) when compared with the period last year. In addition other emerging estimates of COVID impacts based on monthly energy supply1 or estimated parameters2, this study contributes to another step that constructed the near-real-time daily CO2 emission inventories based on activity from power generation (for 29 countries), industry (for 73 countries), road transportation (for 406 cities), aviation and maritime transportation and commercial and residential sectors emissions (for206 countries). The estimates distinguished the decline of CO2 due to COVID-19 from the daily, weekly and seasonal variations as well as the holiday events. The COVID-related decreases in CO2 emissions in road transportation (340.4 Mt CO2, -15.5%), power (292.5 Mt CO2, -6.4% compared to 2019), industry (136.2 Mt CO2, -4.4%), aviation (92.8 Mt CO2, -28.9%), residential (43.4 Mt CO2, - 2.7%), and international shipping (35.9Mt CO2, -15%). Regionally, decreases in China were the largest and earliest (234.5 Mt CO2,-6.9%), followed by Europe (EU-27 & UK) (138.3 Mt CO2, -12.0%) and the U.S. (162.4 Mt CO2, -9.5%). The declines of CO2 are consistent with regional nitrogen oxides concentrations observed by satellites and ground-based networks, but the calculated signal of emissions decreases (about 1Gt CO2) will have little impacts (less than 0.13ppm by April 30, 2020) on the overserved global CO2 concertation. However, with observed fast CO2 recovery in China and partial re-opening globally, our findings suggest the longer-term effects on CO2 emissions are unknown and should be carefully monitored using multiple measures. Copyright © 2020, The Authors. All rights reserved.

关键词： Carbon dioxide

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Input optics systems of the KAGRA detector during O3GK (vol 2023, 023F01, 2023)

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PROGRESS OF THEORETICAL AND EXPERIMENTAL PHYSICS 2023年第5期2023卷

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, Ws 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. Quynh, L. Nguyen Ni, W-T Nishizawa, A. Nozaki, S. Obuchi, Y. Ogaki, W. Oh, J. J. 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. Arellano, F. E. Pena Pinto, I. Sago, N. Saito, S. Saito, Y. Sakai, K. Sakai, Y. Sakuno, Y. Sato, S. Sato, T. Sawada, T. Sekiguchi, T. Sekiguchi, Y. Shao, L. Shibagaki, S. Shimizu, R. Shimoda, T. Shimode, K. Shinkai, H. Shishido, T. Shoda, A. Somiya, K. Son, E. J. Sotani, H. Sugimoto, R. Suresh, J. Suzuki, T. Suzuki, T. Tagoshi, H. Takahashi, H Gravitational Wave Science Project National Astronomical Observatory of Japan 2-21-1 Osawa Mitaka City Tokyo 181-8588 Japan Advanced Technology Center National Astronomical Observatory of Japan 2-21-1 Osawa Mitaka City Tokyo 181-8588 Japan Department of Physics The University of Tokyo 7-3-1 Hongo Bunkyo-ku Tokyo 113-0033 Japan Research Center for the Early Universe The University of Tokyo 7-3-1 Hongo Bunkyo-ku Tokyo 113-0033 Japan Institute for Cosmic Ray Research KAGRA Observatory The University of Tokyo 5-1-5 Kashiwa-no-Ha Kashiwa City Chiba 277-8582 Japan Accelerator Laboratory High Energy Accelerator Research Organization (KEK) 1-1 Oho Tsukuba City Ibaraki 305-0801 Japan Earthquake Research Institute The University of Tokyo 1-1-1 Yayoi Bunkyo-ku Tokyo 113-0032 Japan Department of Mathematics and Physics Graduate School of Science and Technology Hirosaki University 3 Bunkyo-cho Hirosaki Aomori 036-8561 Japan Kamioka Branch National Astronomical Observatory of Japan 238 Higashi-Mozumi Kamioka-cho Hida City Gifu 506-1205 Japan The Graduate University for Advanced Studies (SOKENDAI) 2-21-1 Osawa Mitaka City Tokyo 181-8588 Japan Korea Institute of Science and Technology Information 245 Daehak-ro Yuseong-gu Daejeon 34141 Republic of Korea National Institute for Mathematical Sciences 70 Yuseong-daero 1689 Beon-gil Yuseong-gu Daejeon 34047 Republic of Korea International College Osaka University 1-1 Machikaneyama-cho Toyonaka City Osaka 560-0043 Japan School of High Energy Accelerator Science The Graduate University for Advanced Studies (SOKENDAI) 1-1 Oho Tsukuba City Ibaraki 305-0801 Japan Department of Astronomy Beijing Normal University Xinjiekouwai Street 19 Haidian District Beijing 100875 China Department of Applied Physics Fukuoka University 8-19-1 Nanakuma Jonan Fukuoka City Fukuoka 814-0180 Japan Department of Physics Tamkang University No. 151 Yingzhuan Road Danshui Dist. New Taipei City 25137 Taiwan Department of Physics

KAGRA, the underground and cryogenic gravitational-wave detector, was operated for its solo observation from February 25 to March 10, 2020, and its first joint observation with the GEO 600 detector from April 7 to April 21, 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 kilohertz, whereas the laser intensity did not significantly limit the detector sensitivity.

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A Light Source system of Multi-star Simulator with Adjustable Background and Controllable Magnitude

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空间科学学报 2017年第6期37卷 760-765页

作者： SUN Gaofei LIU Shi ZHANG Guoyu ZHANG Yu LEI Jie MA Yiyuan College of Optoelectronic Engineering Changchun University of Science and Technology Changchun 130022 Optical Measurement and Control Instrumentation Jilin Province Engineering Research Center Changchun 130022 Key Laboratory of Space System Simulation Beijing 100853

A light source of multi-star simulator capable of background adjustment and magnitude control has been *** integrating spheres are employed as the star-point light source and the background light source respectively.A beam splitter prism has been designed to serve as the beam combiner for the star-point and the background light sources,and a mathematical model has been constructed respectively to compute the light flux of the two integrating spheres.A magnitude testing system and a background testing system have been created using low-light illuminometer,luminance meter,and testing instruments to measure the star-point magnitude and the background luminance of the multi-star *** test results suggest that the star-point magnitude is adjustable from0 to+5 m_v,with a simulation precision superior to ±0.026 m_*** maximum background luminance is 3.8×10~5 cd·m^(-2),and the minimum background luminance is6.4×10^(-2)cd·m^(-2).The designed light source system can meet the requirements for simulating the stellar map with a sky background.

关键词： Adjustable background Controllable magnitude Multi-Star simulator Light source

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A roadmap for the atmospheric characterization of terrestrial exoplanets with JWST

arXiv

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arXiv 2023年

作者： de Wit, Julien Doyon, René Rackham, Benjamin V. Lim, Olivia Ducrot, Elsa Kreidberg, Laura Benneke, Björn Ribas, Ignasi Berardo, David Niraula, Prajwal Iyer, Aishwarya Shapiro, Alexander Kostogryz, Nadiia Witzke, Veronika Gillon, Michaël Agol, Eric Meadows, Victoria Burgasser, Adam J. Owen, James E. Fortney, Jonathan J. Selsis, Franck Bello-Arufe, Aaron de Beurs, Zoë Bolmont, Emeline Cowan, Nicolas Dong, Chuanfei Drake, Jeremy J. Garcia, Lionel Greene, Thomas Haworth, Thomas Hu, Renyu Kane, Stephen R. Kervella, Pierre Koll, Daniel Krissansen-Totton, Joshua Lagage, Pierre-Olivier Lichtenberg, Tim Lustig-Yaeger, Jacob Lingam, Manasvi Turbet, Martin Seager, Sara Barkaoui, Khalid Bell, Taylor J. Burdanov, Artem Cadieux, Charles Charnay, Benjamin Cloutier, Ryan Cook, Neil J. Correia, Alexandre C.M. Dang, Lisa Daylan, Tansu Delrez, Laetitia Edwards, Billy Fauchez, Thomas J. Flagg, Laura Fraschetti, Federico Haqq-Misra, Jacob Huang, Ziyu Iro, Nicolas Jayawardhana, Ray Jehin, Emmanuel Jin, Meng Kite, Edwin Kitzmann, Daniel Kral, Quentin Lafrenière, David Libert, Anne-Sophie Liu, Beibei Mohanty, Subhanjoy Morris, Brett M. Murray, Catriona A. Piaulet, Caroline Pozuelos, Francisco J. Radica, Michael Ranjan, Sukrit Rathcke, Alexander Roy, Pierre-Alexis Schwieterman, Edward W. Turner, Jake D. Triaud, Amaury Way, Michael J. Department of Earth Atmospheric and Planetary Science Massachusetts Institute of Technology 77 Massachusetts Avenue CambridgeMA02139 United States Department of Physics Université de Montréal MontrealQC Canada Trottier Institute for Research on Exoplanets Université de Montréal MontrealQC Canada Kavli Institute for Astrophysics and Space Research Massachusetts Institute of Technology CambridgeMA02139 United States Paris Region Fellow Marie Sklodowska-Curie Action France AIM CEA CNRS Université Paris-Saclay Université de Paris Gif-sur-YvetteF-91191 France Max-Planck-Institut für Astronomie Königstuhl 17 HeidelbergD-69117 Germany Campus UAB c/ Can Magrans s/n Bellaterra Barcelona08193 Spain c/ Gran Capità 2–4 Barcelona08034 Spain School of Earth and Space Exploration Arizona State University 525 E. University Dr. TempeAZ85281 United States Max Planck Institute for Solar System Research Göttingen Germany Astrobiology Research Unit Université de Liège 19C Allée du 6 Août Liège4000 Belgium Department of Astronomy and 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 Center for Astrophysics and Space Sciences UC San Diego UCSD Mail Code 0424 9500 Gilman Drive La Jolla CA92093-0424 United States Astrophysics Group Imperial College London Blackett Laboratory Prince Consort Road LondonSW7 2AZ United Kingdom Department of Astronomy and Astrophysics University of California Santa Cruz Santa CruzCA95064 United States Laboratoire d’astrophysique de Bordeaux Univ. Bordeaux CNRS B18N allée Geoffroy Saint-Hilaire Pessac33615 France Jet Propulsion Laboratory California Institute of Technology PasadenaCA United States Observatoire astronomique de l’université de Genève Chemin Pegasi 51 VersoixCH-1290 Switzerland Centre Vie dans l’Univers Faculté des scien

Ultra-cool dwarf stars are abundant, long-lived, and uniquely suited to enable the atmospheric study of transiting terrestrial companions with JWST. Amongst them, the most prominent is the M8.5V star TRAPPIST-1 and its seven planets. While JWST Cycle 1 observations have started to yield preliminary insights into the planets, they have also revealed that their atmospheric exploration requires a better understanding of their host star. Here, we propose a roadmap to characterize the TRAPPIST-1 system—and others like it—in an efficient and robust manner with JWST. We notably recommend that—although more challenging to schedule—multi-transit windows be prioritized to mitigate the effects of stellar activity and gather up to twice more transits per JWST hour spent. We conclude that, for such systems, planets cannot be studied in isolation by small programs, but rather need large-scale, jointly space- and ground-based initiatives to fully exploit the capabilities of JWST for the exploration of terrestrial planets. © 2023, CC BY.

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The Comparison of Different Visual Features for Visual Odometry

The Comparison of Different Visual Features for Visual Odome...

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IEEE Chinese Guidance, Navigation and Control Conference (CGNCC)

作者： Yuehan Jiang Qing Wang Chaoyang Dong Min Zhou Kewei Zhong School of Automation Science and Electrical Engineering Beihang University Beijing People’s Republic of China School of Aeronautic Science and Engineering Beihang University Beijing People’s Republic of China Science and Technology on Special System Simulation Laboratory Beijing Simulation Center Beijing People’s Republic of China Shanghai Aerospace Control Technology Institute Shanghai People’s Republic of China

ISBN: (数字)9781538611715

ISBN: (纸本)9781538611722

For robots to work effectively, the availability of a map with detailed information surrounding the workspace is an important requirement for indoor and outdoor tasks. This is usually achieved with using visual odometry techniques with feature-based methods. In this paper, we compare the performance of three different feature extraction methods: Scale Invariant Feature Transform (SIFT), Speed Up Robust Features (SURF) and Oriented FAST Rotated BRIEF (ORB). This paper presents experimental results on standard evaluation datasets and all experiments use measurement of the number of image correspondences as well as the ratio of good matched for the evaluation purpose. The results of experiments demonstrate that the performances of three methods in processing time, matching capability and accuracy. SIFT presents its stability in most scenarios although it is very slow. SURF is faster than SIFT and outperform SIFT on some scenarios. ORB is the most efficient feature and shows strong performance.

关键词： Feature extraction Detectors Robustness Visualization Transform coding Real-time systems Lighting

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