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Correcting Climate Model Sea Surface Temperature Simulations with Generative Adversarial Networks:Climatology,Interannual Variability,and Extremes

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Advances in Atmospheric sciences 2024年第7期41卷 1299-1312页

作者： Ya WANG Gang HUANG Baoxiang PAN Pengfei LIN Niklas BOERS Weichen TAO Yutong CHEN BO LIU Haijie LI 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 Numerical Modeling Qingdao National Laboratory for Marine Science and TechnologyQingdao 266237China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China Earth System Modelling School of Engineering and DesignTechnical University of MunichOttobrunn 85521Germany Potsdam Institute for Climate Impact Research Potsdam 14412Germany Department of Mathematics and Global Systems Institute University of ExeterExeter EX44QEUK CMA Earth System Modeling and Prediction Centre(CEMC) Chinese Academy of Meteorological SciencesBeijing 100081China

Climate models are vital for understanding and projecting global climate change and its associated ***,these models suffer from biases that limit their accuracy in historical simulations and the trustworthiness of future *** these challenges requires addressing internal variability,hindering the direct alignment between model simulations and observations,and thwarting conventional supervised learning ***,we employ an unsupervised Cycle-consistent Generative Adversarial Network(CycleGAN),to correct daily Sea Surface Temperature(SST)simulations from the Community Earth System Model 2(CESM2).Our results reveal that the CycleGAN not only corrects climatological biases but also improves the simulation of major dynamic modes including the El Niño-Southern Oscillation(ENSO)and the Indian Ocean Dipole mode,as well as SST ***,it substantially corrects climatological SST biases,decreasing the globally averaged Root-Mean-Square Error(RMSE)by 58%.Intriguingly,the CycleGAN effectively addresses the well-known excessive westward bias in ENSO SST anomalies,a common issue in climate models that traditional methods,like quantile mapping,struggle to ***,it substantially improves the simulation of SST extremes,raising the pattern correlation coefficient(PCC)from 0.56 to 0.88 and lowering the RMSE from 0.5 to *** enhancement is attributed to better representations of interannual,intraseasonal,and synoptic scales *** study offers a novel approach to correct global SST simulations and underscores its effectiveness across different time scales and primary dynamical modes.

关键词： generative adversarial networks model bias deep learning El Niño-Southern Oscillation marine heatwaves

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Digital predistortion, all-digital transmitter, baseband equivalent model

arXiv

引用

arXiv 2017年

作者： Lin, De-Ye Song, Haifeng Hui, Xi Dong State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing Beijing100083 Institute of Applied Physics and Computational Mathematics Fenghao East Road 2 Beijing100094 CAEP Software Center for High Performance Numerical Simulation Huayuan Road 6 Beijing100088

In this work, a many-body potential of Nb for radiation damage simulation was developed based on embedded-atom-method (EAM), and most of the point defects of Nb can be predicted properly by this potential. By using the constructed potential, the direction-specific threshold displacement energies (TDE) and displacement cascades up to 20 keV of Nb were performed through molecular dynamics simulations. The calculated results of TDE are in good agreement with previous work for V, Mo and experimental measurements. Lowest TDE was found in direction, and local minas of TDE were found in three low-index directions, which has relation:E[100]dE[111]dE[110]d. The evolution of displacement cascades, number of the created point defects, the cascade efficiency the clustering of point defects, and temperature role of these parameters at different PKA energies were systematic investigated. It is found that the cascade efficiency is low and it is can be fitted by a power function as many published work did. The fraction of clustered point defects obtained in this work is low, and only some small clusters were formed at the end of thermal spike. As the temperature increases, the productions of point defects and cascade efficiency were somewhat decreases, however, the fraction of clustered point defects decreases more obvious. Copyright © 2017, The Authors. All rights reserved.

关键词： Molecular dynamics

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Accelerating relaxation through Liouvillian exceptional point

arXiv

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arXiv 2023年

作者： Zhou, Yan-Li Yu, Xiao-Die Wu, Chun-Wang Li, Xie-Qian Zhang, Jie Li, Weibin Chen, Ping-Xing Institute for Quantum Science and Technology College of Science National University of Defense Technology Changsha410073 China Hunan Key Laboratory of Mechanism and Technology of Quantum Information Changsha410073 China Hefei National Laboratory Anhui Hefei230088 China College of Science National University of Defense Technology Changsha410073 China School of Physics and Astronomy Centre for the Mathematics and Theoretical Physics of Quantum Non-Equilibrium Systems University of Nottingham NottinghamNG7 2RD United Kingdom

We investigate speeding up of relaxation of Markovian open quantum systems with the Liouvillian exceptional point (LEP), where the slowest decay mode degenerate with a faster decay mode. The degeneracy significantly increases the gap of the Liouvillian operator, which determines the timescale of such systems in converging to stationarity, and hence accelerates the relaxation process. We explore an experimentally relevant three level atomic system, whose eigenmatrices and eigenspectra are obtained completely analytically. This allows us to gain insights in the LEP and examine respective dynamics with details. We illustrate that the gap can be further widened through Floquet engineering, which further accelerates the relaxation process. Finally, we extend this approach to analyze laser cooling of trapped ions, where vibrations (phonons) couple to the electronic states. An optimal cooling condition is obtained analytically, which agrees with both existing experiments and numerical simulations. Our study provides analytical insights in understanding LEP, as well as in controlling and optimizing dissipative dynamics of atoms and trapped ions. Copyright © 2023, The Authors. All rights reserved.

关键词： Trapped ions

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Assessing the nonequilibrium of decaying turbulence with reversed initial fields

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Physical Review Fluids 2019年第8期4卷 084603-084603页

作者： F. Liu (刘锋) L. P. Lu (陆利蓬) Wouter J. T. Bos L. Fang (方乐) Laboratory of Mathematics and Physics Ecole Centrale de Pékin Beihang University Beijing 100191 China National Key Laboratory of Science and Technology on Aero-Engine Aero-Thermodynamics School of Energy and Power Engineering Beihang University Beijing 100191 China LMFA CNRS Ecole Centrale de Lyon–Université de Lyon 69130 Ecully France

Recently, it was observed that in nonequilibrium turbulent flows the normalized dissipation rate depends in a fairly universal way on the Reynolds number of the flow. To assess theoretical explanations of this observation, we consider here the nonequilibrium properties of freely decaying turbulence from initial conditions where the velocity field is reversed in every point in space. This test-case allows us to manipulate a turbulent flow differently from the usual way, where nonequilibrium is induced by modification of large-scale forcing mechanisms. It is shown that it is possible to obtain a different Reynolds-dependent scaling of the dissipation rate, which can be derived directly as a perturbation around the equilibrium state.

关键词： Self-organized systems Turbulence Navier-Stokes equation

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Joint mass-and-energy test of the equivalence principle at the 10−10 level using atoms with specified mass and internal energy

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Physical Review A 2021年第2期104卷 022822-022822页

作者： Lin Zhou Chuan He Si-Tong Yan Xi Chen Dong-Feng Gao Wei-Tao Duan Yu-Hang Ji Run-Dong Xu Biao Tang Chao Zhou Sachin Barthwal Qi Wang Zhuo Hou Zong-Yuan Xiong Yuan-Zhong Zhang Min Liu Wei-Tou Ni Jin Wang Ming-Sheng Zhan 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 Sciences-Wuhan National Laboratory for Optoelectronics Wuhan 430071 China School of Physical Sciences University of Chinese Academy of Sciences Beijing 100049 China Light and Matter Physics Raman Research Institute Sadashivanagar Bangalore 560080 India Institute of Theoretical Physics Chinese Academy of Sciences Beijing 100190 China

We use rubidium atoms with specified mass and internal energy to carry out a joint mass-energy test of the equivalence principle (EP). We improve the four-wave double-diffraction Raman transition method (4WDR) we proposed before to select atoms with a certain mass and angular momentum state, and form a dual-species atom interferometer. By using the extended 4WDR to Rb85 and Rb87 atoms with different angular momenta, we measure their differential gravitational acceleration, and we determine the value of the Eötvös parameter, η, which measures the strength of the violation of EP. The Eötvös parameters of the four paired combinations Rb85|F=2〉−Rb87|F=1〉, Rb85|F=2〉−Rb87|F=2〉, Rb85|F=3〉−Rb87|F=1〉, and Rb85|F=3〉−Rb87|F=2〉 were measured to be η1=(1.5±3.2)×10−10, η2=(−0.6±3.7)×10−10, η3=(−2.5±4.1)×10−10, and η4=(−2.7±3.6)×10−10, respectively. The violation parameter of mass is constrained to η0=(−0.8±1.4)×10−10, and that of internal energy to ηE=(0.0±0.4)×10−10 per reduced energy ratio a (a=hν0/mi85c2, and ν0=1 GHz). This work opens a door for joint tests of two attributes beyond the traditional pure mass or energy tests of EP with quantum systems.

关键词： Atom interferometry Coherent control Atoms Mach-Zehnder atom interferometry

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DID Code:A Bridge Connecting the Materials Genome Engineering Database w让h Inheritable Integrated Intelligent Manufacturing

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Engineering 2020年第6期6卷 612-620页

作者： William Yi Wang Peixuan Li Deye Lin Bin Tang Jun Wang Quanmei Guan Qian Ye Haixing Dai Jun Gao Xiaoli Fan Hongchao Kou Haifeng Song Feng Zhou Jijun Ma Zi-Kui Liu Jinshan Li Weimin Liu State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi'an 710072China CAEP Software Center for High Performance Numerical Simulation Institute of Applied Physics and Computational MathematicsBeijing 100088China CRRC Tangshan Co. Ltd.Tangshan 063035China Beijing Star Travel Space Technology Co. Ltd.Beijing 100013China Department of Materials Science and Engineering Pennsylvania State UniversityUniversity ParkPA 16802USA

A data identifier(DID)is an essential tag or label in all kinds of databases—particularly those related to integrated computational materials engineering(ICME),inheritable integrated intelligent manufacturing(I3M),and the Industrial Internet *** the guidance and quick acceleration of the developme nt of advanced materials,as envisioned by official documents worldwide,more investigations are required to construct relative numerical standards for material *** work proposes a universal DID format consisting of a set of build chains,which aligns with the classical form of identifier in both international and national standards,such as ISO/IEC 29168-1:2000,GB/T 27766-2011,GA/T 543.2-2011,GM/T 0006-2012,GJB 7365-2011,SL 325-2014,SL 607-201&WS 363.2-2011,and QX/T *** build chain is made up of capital letters and numbers,with no ***,the total length of each build chain is not restricted,which follows the formation of the Universal Coded Character Set in the international standard of ISO/IEC *** on these rules,the proposed DID is flexible and convenient for extendi ng and sharing in and between various cloud-based ***,classical two-dimensional(2D)codes,including the Hanxin Code,Lots Perception Matrix(LP)Code,Quick Response(Q.R)code,Grid Matrix(GM)code,and Data Matrix(DM)Code,can be constructed and precisely recognized and/or decoded by either smart phones or specific *** utilizing these 2D codes as the fingerprints of a set of data linked with cloud-based platforms,progress and updates in the composition-processing-structure-property-performance workflow process can be tracked spontaneously,paving a path to accelerate the discovery and manufacture of advanced materials and enhance research productivity,performance,and collaboration.

关键词： Data identifier Database Digital twin Integrated computational materials engineering

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Experimental test of the irreducible four-qubit Greenberger-Horne-Zeilinger paradox

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Physical Review A 2017年第3期95卷 030103(R)-030103(R)页

作者： Zu-En Su Wei-Dong Tang Dian Wu Xin-Dong Cai Tao Yang Li Li Nai-Le Liu Chao-Yang Lu Marek Żukowski Jian-Wei Pan Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics University of Science and Technology of China Hefei Anhui 230026 China CAS Centre for Excellence and Synergetic Innovation Centre in Quantum Information and Quantum Physics University of Science and Technology of China Hefei Anhui 230026 China Key Laboratory of Quantum Information and Quantum Optoelectronic Devices Shanxi Province and Department of Applied Physics of Xi'an Jiaotong University Xi'an 710049 China Institute for Theoretical Physics and Astrophysics Faculty of Mathematics and Informatics University of Gdansk Wita Stwosza 57 80-308 Gdansk Poland

The paradox of Greenberger-Horne-Zeilinger (GHZ) disproves directly the concept of EPR elements of reality, based on the EPR correlations, in an all-versus-nothing way. A three-qubit experimental demonstration of the GHZ paradox was achieved nearly 20 years ago, followed by demonstrations for more qubits. Still, the GHZ contradictions underlying the tests can be reduced to a three-qubit one. We show an irreducible four-qubit GHZ paradox, and report its experimental demonstration. The bound of a three-setting-per-party Bell-GHZ inequality is violated by 7σ. The fidelity of the GHZ state was around 81%, and an entanglement witness reveals a violation of the separability threshold by 19σ.

关键词： Nonlocality Quantum entanglement Quantum foundations Quantum measurements

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Adaptive multi-resolution 3D Hartree-Fock-Bogoliubov solver for nuclear structure

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Physical Review C 2014年第2期90卷 024317-024317页

作者： J. C. Pei (裴俊琛) G. I. Fann R. J. Harrison W. Nazarewicz Yue Shi (石跃) S. Thornton State Key Laboratory of Nuclear Physics and Technology School of Physics Peking University Beijing 100871 China Department of Physics and Astronomy University of Tennessee Knoxville Tennessee 37996 USA Joint Institute for Nuclear Physics and Applications Oak Ridge National Laboratory Oak Ridge Tennessee 37831 USA Computer Science and Mathematics Division Oak Ridge National Laboratory Oak Ridge Tennessee 37831 USA Institute for Advanced Computational Science Stony Brook University Stony Brook New York 11794 USA Computational Science Center Brookhaven National Laboratory Upton New York 11973 USA Physics Division Oak Ridge National Laboratory Oak Ridge Tennessee 37831 USA Institute of Theoretical Physics Faculty of Physics University of Warsaw ul. Hoża 69 PL-00681 Warsaw Poland

Background: Complex many-body systems, such as triaxial and reflection-asymmetric nuclei, weakly bound halo states, cluster configurations, nuclear fragments produced in heavy-ion fusion reactions, cold Fermi gases, and pasta phases in neutron star crust, are all characterized by large sizes and complex topologies in which many geometrical symmetries characteristic of ground-state configurations are broken. A tool of choice to study such complex forms of matter is an adaptive multi-resolution wavelet analysis. This method has generated much excitement since it provides a common framework linking many diversified methodologies across different fields, including signal processing, data compression, harmonic analysis and operator theory, fractals, and quantum field theory.

关键词： ENERGY-band theory of solids NUCLEAR structure RESEARCH NUCLEAR density numerical analysis -- Software FERMIONS

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Complex-valued K-means clustering of interpolative separable density fitting algorithm for large-scale hybrid functional enabled ab initio molecular dynamics simulations within plane waves

arXiv

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arXiv 2022年

作者： Jiao, Shizhe Li, Jielan Qin, Xinming Wan, Lingyun Hu, Wei Yang, Jinlong Hefei National Research Center for Physical Sciences at the Microscale Anhui Center for Applied Mathematics University of Science and Technology of China Anhui Hefei230026 China Key Laboratory of Precision and Intelligent Chemistry Department of Chemical Physics University of Science and Technology of China Anhui Hefei230026 China

K-means clustering, as a classic unsupervised machine learning algorithm, is the key step to select the interpolation sampling points in interpolative separable density fitting (ISDF) decomposition. Real-valued K-means clustering for accelerating the ISDF decomposition has been demonstrated for large-scale hybrid functional enabled ab initio molecular dynamics (hybrid AIMD) simulations within plane-wave basis sets where the Kohn-Sham orbitals are real-valued. However, it is unclear whether such K-means clustering works for complex-valued Kohn-Sham orbitals. Here, we apply the K-means clustering into hybrid AIMD simulations for complex-valued Kohn-Sham orbitals and use an improved weight function defined as the sum of the square modulus of complex-valued Kohn-Sham orbitals in K-means clustering. numerical results demonstrate that this improved weight function in K-means clustering algorithm yields smoother and more delocalized interpolation sampling points, resulting in smoother energy potential, smaller energy drift and longer time steps for hybrid AIMD simulations compared to the previous weight function used in the real-valued K-means algorithm. In particular, we find that this improved algorithm can obtain more accurate oxygen-oxygen radial distribution functions in liquid water molecules and more accurate power spectrum in crystal silicon dioxide compared to the previous K-means algorithm. Finally, we describe a massively parallel implementation of this ISDF decomposition to accelerate large-scale complex-valued hybrid AIMD simulations containing thousands of atoms (2,744 atoms), which can scale up to 5,504 CPU cores on modern supercomputers. © 2022, CC BY.

关键词： Molecular dynamics

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Magnetic and topological transitions in three-dimensional topological Kondo insulator

arXiv

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arXiv 2018年

作者： Li, Huan Wang, Zhi-Yong Zheng, Xiao-Jun Liu, Yu Zhong, Yin College of Science Guilin University of Technology Guilin541004 China Institute of Applied Physics and Computational Mathematics Beijing100088 China Software Center for High Performance Numerical Simulation China Academy of Engineering Physics Beijing100088 China Center for Interdisciplinary Studies & Key Laboratory for Magnetism and Magnetic Materials of the MoE Lanzhou University Lanzhou730000 China

By using an extended slave-boson method, we draw a global phase diagram summarizing both magnetic phases and paramagnetic (PM) topological insulating phases (TIs) in three-dimensional topological Kondo insulator (TKI). By including electron hopping (EH) up to third neighbor, we identify four strong topological insulating (STI) phases and two weak topological insulating (WTI) phases, then the PM phase diagrams characterizing topological transitions between these TIs are depicted as functions of EH, f-electron energy level and hybridization constant. We also find an insulator-metal transition from a STI phase which has surface Fermi rings and spin textures in qualitative agreement to TKI candidate SmB6. In weak hybridization regime, anti-ferromagnetic (AF) order naturally arises in the phase diagrams, and depending on how the magnetic boundary crosses the PM topological transition lines, AF phases are classified into AF topological insulator (AFTI) and non-topological AF insulator (nAFI), according to their Z2 indices. In two small regions of parameter space, two distinct topological transition processes between AF phases occur, leading to two types of AFTI, showing distinguishable surface dispersions around their Dirac points. Copyright © 2018, The Authors. All rights reserved.

关键词： Phase diagrams

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