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Measurement of high energy cosmic rays by the new Tibet hybrid experiment 35

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Measurement of high energy cosmic rays by the new Tibet hybr...

35th International Cosmic Ray Conference, ICRC 2017

作者： Amenomori, M. Bi, X.J. Chen, D. Chen, T.L. Chen, W.Y. Cui, S.W. Danzengluobu Ding, L.K. Feng, C.F. Feng, Zhaoyang Feng, Z.Y. Gou, Q.B. Guo, Y.Q. He, H.H. He, Z.T. Hibino, K. Hotta, N. Hu, Haibing Hu, H.B. Huang, J. Jia, H.Y. Jiang, L. Kajino, F. Kasahara, K. Katayose, Y. Kato, C. Kawata, K. Kozai, M. Labaciren Le, G.M. Li, A.F. Li, H.J. Li, W.J. Liu, C. Liu, J.S. Liu, M.Y. Lu, H. Meng, X.R. Miyazaki, T. Mizutani, K. Munakata, K. Nakajima, T. Nakamura, Y. Nanjo, H. Nishizawa, M. Niwa, T. Ohnishi, M. Ohta, I. Ozawa, S. Qian, X.L. Qu, X.B. Saito, T. Saito, T.Y. Sakata, M. Sako, T.K. Shao, J. Shibata, M. Shiomi, A. Shirai, T. Sugimoto, H. Takita, M. Tan, Y.H. Tateyama, N. Torii, S. Tsuchiya, H. Udo, S. Wang, H. Wu, H.R. Xue, L. Yamamoto, Y. Yamauchi, K. Yang, Z. Yuan, A.F. Yuda, T. Zhai, L.M. Zhang, H.M. Zhang, J.L. Zhang, X.Y. Zhang, Y. Zhang, Yi Zhang, Ying Zhaxisangzhu Zhou, X.X. Department of Physics Hirosaki University Japan Key Laboratory of Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences China National Astronomical Observatories Chinese Academy of Sciences China Department of Mathematics and Physics Tibet University China Department of Physics Hebei Normal University China Department of Physics Shandong University China Institute of Modern Physics SouthWest Jiaotong University China Faculty of Engineering Kanagawa University Japan Faculty of Education Utsunomiya University Japan Department of Physics Konan University Japan Research Institute for Science and Engineering Waseda University Japan Faculty of Engineering Yokohama National University Japan Department of Physics Shinshu University Japan Institute for Cosmic Ray Research University of Tokyo Japan Japan National Center for Space Weather China Meteorological Administration China School of Information Science and Engineering Shandong Agriculture University China Saitama University Japan National Institute of Informatics Japan Sakushin Gakuin University Japan College of Science China University of Petroleum China Tokyo Metropolitan College of Industrial Technology Japan Max-Planck-Institut für Physik Germany Escuela de Ciencias Físicas y Nanotechnología Yachay Tech. Ecuador College of Industrial Technology Nihon University Japan Shonan Institute of Technology Japan Japan Atomic Energy Agency Japan

We have started a new hybrid air shower experiment at Yangbajing (4300 m a.s.l.) in Tibet in February 2014. This new hybrid experiment consists of the YAC-II comprised of 124 core detectors placed in the form of a square grid of 1.9 m spacing covering about 500 m2, the Tibet-III air shower array with the total area of about 50, 000 m2 and the underground MD array consisting of 80 cells, with the total area of about 4, 200 m2. This hybrid-array system is used to observe air showers of high energy celestial gamma-ray origin and those of nuclear-component origin. In this paper, a short review of the experiment will be followed by an overview on the current results on energy spectrum and chemical composition of CRs and test of hadronic interaction models. © Copyright owned by the author(s) under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives 4.0 International License (CC BY-NC-ND 4.0).

关键词： Gamma rays

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南大洋增暖及其气候影响

science Bulletin 2023年第9期68卷 946-960,M0004页

作者：蔡文炬高立宝罗义勇李熙晨郑小童张学斌程旭华贾凡 Ariaan Purich Agus Santoso 杜岩 David MHolland 石佳睿项宝强谢尚平 Frontiers Science Center for Deep Ocean Multispheres and Earth System and Key Laboratory of Physical Oceanography Ocean University of ChinaQingdao 266100China Laboratory for Ocean and Climate Dynamics Pilot National Laboratory for Marine Science and TechnologyQingdao 266237China Center for Southern Hemisphere Oceans Research Commonwealth Scientific and Industrial Research Organisation(CSIRO)Oceans and AtmosphereHobart 7004Australia First Institute of Oceanography and Key Laboratory of Marine Science and Numerical Modeling Ministry of Natural ResourcesQingdao 266061China Laboratory for Regional Oceanography and Numerical Modeling Pilot National Laboratory for Marine Science and TechnologyQingdao 266237China Institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100029China College of Oceanography Hohai UniversityNanjing 210098China Key Laboratory of Ocean Circulation and Waves Institute of OceanologyChinese Academy of SciencesQingdao 266071China Climate Change Research Centre University of New South WalesSydney 2052Australia Australian Research Council Centre of Excellence for Climate Extremes University of New South WalesSydney 2052Australia State Key Laboratory of Tropical Oceanography South China Sea Institute of OceanologyChinese Academy of SciencesGuangzhou 510301China Southern Marine Science and Engineering Guangdong Laboratory Guangzhou 511458China Courant Institute of Mathematical Sciences New York UniversityNew York NY 10012USA Woods Hole Oceanographic Institution Woods Hole MA 02543USA NOAA/Geophysical Fluid Dynamics Laboratory Princeton NJ 08540USA University Corporation for Atmospheric Research Boulder CO 80307USA Scripps Institution of Oceanography University of California San DiegoLa Jolla CA 92093USA

过去几十年南大洋在南极平流层臭氧消耗和大气二氧化碳浓度增加的共同作用下大幅增暖,显著影响着南极冰架和冰盖的融化、海平面上升、南北半球的降水分配以及热带海洋和大气环流等,引发了深远的气候效应.全球变暖背景下南大洋西风表现... 详细信息

过去几十年南大洋在南极平流层臭氧消耗和大气二氧化碳浓度增加的共同作用下大幅增暖,显著影响着南极冰架和冰盖的融化、海平面上升、南北半球的降水分配以及热带海洋和大气环流等,引发了深远的气候效应.全球变暖背景下南大洋西风表现为极向加强,同时进入南大洋的热辐射和淡水通量持续增加,由此上翻的海水可吸收更多的热量和碳,经由更强的平均流向北输送,更多地在45°S附近海域下沉并存储.当前对南大洋增暖背后诸多复杂的物理过程仍缺乏足够的理解,比如来自冰架、冰盖及海洋涡旋的作用、热带-极地相互作用、南大洋本身对全球变暖的响应等,尤其是有限的观测数据和较低分辨率的模式无法准确呈现快速变化的物理现象和机理.因此,南大洋的未来增暖存在很大的不确定性且可能长期持续,但近期的进展为深入认知南大洋增暖及其气候影响奠定了坚实的基础.

关键词：平流层臭氧南大洋物理现象物理过程全球变暖热带海洋南北半球低分辨率

Graph-GIC: A Smart and Parallelized Geomagnetically Induced Current Modelling Algorithm Based on Graph Theory for Space Weather Applications

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arXiv 2024年

作者： Chen, Wen Yuan, Ding Feng, Xueshang Poedts, Stefaan Zou, Zhengyang Feng, Song Zhu, Yuxuan Yin, Tong Shenzhen Key Laboratory of Numerical Prediction for Space Storm School of Aerospace Harbin Institute of Technology Guangdong Shenzhen518055 China Key Laboratory of Solar Activity and Space Weather National Space Science Center Chinese Academy of Sciences Beijing China Centre for Mathematical Plasma Astrophysics Department of Mathematics KU Leuven LeuvenB-3001 Belgium State Key Laboratory of Lunar and Planetary Sciences Macau University of Science and Technology China Faculty of Information Engineering and Automation Kunming University of Science and Technology Kunming650500 China Institute of Physics University of Maria Curie-Sklodowska ul. Marii Curie-Sklodowskiej 1 Lublin20-031 Poland

Geomagnetically Induced Current (GIC) refers to the electromagnetic response of the Earth and its conductive modern infrastructures to space weather and would pose a significant threat to high-voltage power grids designed for the alternative current operation. To assess the impact of space weather on the power grid, one needs to calculate the GIC on a national or continental scale. In this study, we developed a smart and parallelized GIC modelling algorithm, Graph GIC. This algorithm deploys a graph representing a power grid in a single-line diagram, in which substations/transformers act as nodes and transmission lines as edges. With these denotations, a power grid and its electric parameters are mathematically represented with an adjacency matrix and an admittance matrix. We used sparse matrix and parallelisation techniques to expedite the intensive computation in cases of large-scale power grids. The Graph GIC was validated with a benchmark grid, applied to the GIC calculation of the 500 kV power grid of Guangdong, China, and conducted preliminary analysis on the grid’s susceptibility to geomagnetic storms. The Graph GIC algorithm has the advantage of an intuitive and highly scalable graph representation of a power grid at any scale. It achieves high-accuracy calculation and a speedup of about 18 times after parallelisation. This algorithm could be applied to assess the impact of space weather on a power grid up to continental scales and could be incorporated into global space weather modelling frameworks. Copyright © 2024, The Authors. All rights reserved.

关键词： Matrix algebra

Rho-pion transition form factors in the kT-factorization formalism revisited

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Physical Review D 2018年第11期97卷 113002-113002页

作者： Jun Hua Shan Cheng Ya-lan Zhang Zhen-Jun Xiao Department of Physics and Institute of Theoretical Physics Nanjing Normal University Nanjing Jiangsu 210023 People’s Republic of China School of Physics and Microelectronics Science Hunan University Changsha Hunan 410082 People’s Republic of China Department of Faculty of Mathematics and Physics Huaiyin Institute of Technology Huaian Jiangsu 223001 People’s Republic of China Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems Nanjing Normal University Nanjing Jiangsu 210023 People’s Republic of China

We revisit the evaluations for the spacelike and timelike ρπ transition form factors Fρπ(Q2) and Gρπ(Q2) with the inclusion of the next-to-leading order (NLO) QCD contributions in the framework of the kT-factorization theorem. The infrared divergence is regularized by the transversal momentum carried by external valence quarks, and ultimately absorbed into the meson wave functions. In the region of Q2≤2 GeV2, where the perturbative QCD factorization approach is applicable, the NLO contribution can bring no larger than 35% enhancement to the spacelike form factor Fρπ(Q2). For the timelike form factor derived under the kinematic exchanging symmetry, this contribution is also under control when the momentum transfer squared is large enough. We also prolong our prediction into the small Q2 region by taking the lattice QCD results into account, and subsequently obtain the coupling gρπγ=Gρπ(0)=0.596.

关键词： Form factors

Z2classification for a novel antiferromagnetic topological insulating phase in three-dimensional topological Kondo insulator

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arXiv 2018年

作者： Li, Huan Zhong, Yin Liu, Yu Luo, Hong-Gang Song, Hai-Feng College of Science Guilin University of Technology Guilin541004 China Center for Interdisciplinary Studies Key Laboratory for Magnetism and Magnetic Materials of the MoE Lanzhou University Lanzhou730000 China Institute of Applied Physics and Computational Mathematics Beijing100088 China Software Center for High Performance Numerical Simulation China Academy of Engineering Physics Beijing100088 China Beijing Computational Science Research Center Beijing100084 China

Antiferromagnetic topological insulator (AFTI) is a topological matter that breaks time-reversal symmetry. Since its proposal, explorations of AFTI in strong-correlated systems are still lacking. In this paper, we show for the first time that a novel AFTI phase can be realized in three-dimensional topological Kondo insulator (TKI). In a wide parameter region, the ground states of TKI undergo a second-order transition to antiferromagnetic insulating phases which conserve a combined symmetry of time reversal and a lattice translation, allowing us to derive a Z2-classification formula for these states. By calculating the Z2index, the antiferromagnetic insulating states are classified into (AFTI) or non-topological antiferromagnetic insulator (nAFI) in different parameter regions. On the antiferromagnetic surfaces in AFTI, we find topologically protected gapless Dirac cones inside the bulk gap, leading to metallic Fermi rings exhibiting helical spin texture with weak spin-momentum locking. Depending on model parameters, the magnetic transitions take place either between AFTI and strong topological insulator, or between nAFI and weak topological insulator. By varying some model parameters, we find a topological transition between AFTI and nAFI, driving by closing of bulk gap. Our work may account for the pressure-induced magnetism in TKI compound SmB6, and helps to explore richer AFTI phases in heavyfermion systems as well as in other strong-correlated systems. Copyright © 2018, The Authors. All rights reserved.

关键词： Antiferromagnetism

Universality of the dynamic characteristic relationship of electron correlation in the two-photon double ionization process of a helium-like system

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arXiv 2020年

作者： Li, Fei Yang, Yu-Jun Chen, Jing Liu, Xiao-Jun Wei, Zhi-Yi Wang, Bing-Bing Laboratory of Optical Physics Beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Beijing100190 China Institute of Atomic and Molecular Physics Jilin University Changchun130012 China Institute of Applied Physics and Computational Mathematics P. O. Box 8009 Beijing100088 China HEDPS Center for Applied Physics and Technology Peking University Beijing100084 China State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics Wuhan Institute of Physics and Mathematics Innovation Academy for Precision Measurement Science and Technology Chinese Academy of Science Wuhan430071 China University of Chinese Academy of Sciences Beijing100049 China

Universality of the dynamic characteristic relationship between the characteristic time tc and the two-electron Coulomb interaction energy V 12 of the ground state in the two-photon double ionization process is investigated through changing the parameters of the two-electron atomic system and the corresponding laser conditions. The numerical results show that the product tcV 12 keeps constant around 4.1 in the cases of changing the nucleus charge, the electron charge, the electron mass, and changing simultaneously the nucleus charge and the electron charge. These results demonstrate that the dynamic characteristic relationship in the two-photon double ionization process is universal. This work sheds more light on the the dynamic characteristic relationship in ultrafast processes and may find its application in the measurement of attosecond pulses. Copyright © 2020, The Authors. All rights reserved.

关键词： Helium

A verification approach for Web service compositions based on epistemic model checking

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Jisuanji Xuebao/Chinese Journal of Computers 2011年第6期34卷 1041-1061页

作者： Luo, Xiang-Yu Tan, Zheng Su, Kai-Le Wu, Li-Jun College of Computer Science and Technology Huaqiao University Xiamen Fujian 361021 China School of Software Tsinghua University Beijing 100084 China No 504 Plant China National Nuclear Corporation Lanzhou 730065 China Key Laboratory of High Confidence Software Technologies of Ministry of Education Peking University Beijing 100871 China College of Mathematics Physics and Information Engineering Zhejiang Normal University Jinhua Zhejiang 321004 China School of Computer Science and Engineering University of Electronic Science and Technology Chengdu 410073 China

In recent years, the formal verification of Web service compositions is gradually becoming a hot research area. As a mainstream technique for formal verification, model checking is able to not only overcome the shortcoming of traditional software test techniques that they cannot generate the complete set of test cases, but also automatizes the verification process. In this paper, the authors propose and implement an epistemic model checking approach for the verification of Web service compositions by modeling them as multi-agent systems. After analyzing the BPEL control flow, the authors first propose a formal model for the BPEL activities and give the semantics of the implementation of the BPEL activities. By taking the so-call transition seven-tuple as the intermediate form, the authors further develop two automatic transform algorithms, one converts the BPEL process to the set of seven-tuples and the other converts this set of seven-tuples to the input language of MCTK (a model checker for multi-agent systems developed by the authors), such that can finally implement the verification by MCTK. The experimental results show that the proposed algorithms can effectively verify not only the temporal logical specifications, but also the temporal epistemic logical specifications, which are proper to multi-agent systems.

关键词： Model checking

Critical climate issues toward carbon neutrality targets

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Fundamental Research 2022年第3期2卷 396-400页

作者： Gang Huang Zhenhao Xu Xia Qu Junji Cao Shangmin Long Kai Yang Hongyu Hou Ya Wang Xiaofan Ma State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Laboratory for Regional Oceanography and NumericalModeling Qingdao National Laboratory for Marine Science and TechnologyQingdao 266237China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China Institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100029China International Polar Environment Research Laboratory College of OceanographyHohai UniversityNanjing 210098China

In 2020,China announced the"emission peak,carbon neutrality"policy,that is,China aims to have CO2 emissions peak before 2030 and achieve carbon neutrality before *** scenario of carbon neutrality will be significantly distinguished from the scenario we experienced since the industrial ***,instrumental data are unavailable in the future carbon-neutral *** system models and climate dynamics theory are needed to comprehend and project the climate *** this paper,we illustrate our perspective of the issues related to"emission peak,carbon neutrality",including climate dynamics,climate-carbon feedback,interaction between China and global climate and carbon emissions and solutions,*** highlight that climate change has profoundly affected human production and *** frequent occurrence of extreme weather disasters in recent years,together with the impact of epidemics,make the future"carbon peak&carbon-neutral"scenario more *** is whopping uncertainty but also a massive challenge to the scientific ***,carbon neutrality is closely related to domestic production and lives,and there is little time left for *** believe that we will make a breakthrough in climate dynamics in the context of carbon neutrality with our joint efforts,which will serve our country’s carbon emission policy at different stages.

关键词： Carbon neutrality Climate dynamics Climate-carbon feedback Diplomacy Possible solutions Future prospect

Subspace method based on neural networks for eigenvalue problems

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arXiv 2024年

作者： Dai, Xiaoying Fan, Yunying Sheng, Zhiqiang LSEC Institute of Computational Mathematics and Scientific/Engineering Computing Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing100190 China School of Mathematical Sciences University of Chinese Academy of Sciences Beijing100049 China National Key Laboratory of Computational Physics Institute of Applied Physics and Computational Mathematics Beijing100088 China HEDPS Center for Applied Physics and Technology College of Engineering Peking University Beijing100871 China

With the rapid development of machine learning, numerical discretization methods based on deep neural networks have been widely used in many fields, especially in solving high-dimensional problems where traditional methods face bottlenecks. However, for low-dimensional problems, existing machine learning methods are not as accurate and efficient as traditional methods. In this paper, we propose a subspace method based on neural networks for eigenvalue problems with high accuracy and low cost. Our basic idea is to use neural network based basis functions to span a subspace, then calculate the parameters of the neural network based basis functions through appropriate training, and finally calculate the Galerkin projection of the eigenvalue problem onto the subspace and obtain an approximate solution. In addition, we reduce the dimension of the subspace by applying some dimensionality reduction technique, which can improve the accuracy of the approximate solution in further. numerical experiments show that we can obtain approximate eigenvalues with accuracy of 10−11 but with less then 400 epochs, which is significantly superior to other existing neural network based *** Codes 65N25, 65L15, 68T07 Copyright © 2024, The Authors. All rights reserved.

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