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arXiv 2024年

作者： Franken, Arnout D. Luesink, Erwin Ephrati, Sagy R. Geurts, Bernard J. Mathematics of Multiscale Modelling and Simulation Department of Applied Mathematics Faculty EEMCS University of Twente PO Box 217 Enschede7500 AE Netherlands Korteweg-de-Vries Institute University of Amsterdam PO Box 94248 Science Park 107 Amsterdam1090 GE Netherlands Department of Mathematical Sciences Chalmers University of Technology Gothenburg412 96 Sweden Multiscale Physics Center for Computational Energy Research Department of Applied Physics Eindhoven University of Technology Eindhoven Netherlands

Accurate long-term predictions of large-scale flow features on planets are crucial for understanding global atmospheric and oceanic systems, necessitating the development of numerical methods that can preserve essential physical structures over extended simulation periods without excessive computational costs. Recent advancements in the study of global single-layer barotropic models have led to novel numerical methods based on Lie-Poisson discretization that preserve energy, enstrophy and higher-order moments of potential vorticity. This work extends this approach to more complex stratified quasi-geostrophic (QG) systems on the sphere. In this work, we present a formulation of the multi-layer QG equations on the full globe. This allows for extending the Lie-Poisson discretization to multi-layer QG models, ensuring consistency with the underlying structure and enabling long-term simulations without additional regularization. The numerical method is benchmarked through simulations of forced geostrophic turbulence and the long-term behaviour of unforced multi-layered systems. These results demonstrate the structure-preserving properties and robustness of the proposed numerical method, paving the way for a better understanding of the role of high-order conserved quantities in large-scale geophysical flow dynamics. Copyright © 2024, The Authors. All rights reserved.

关键词： Atmospheric movements

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Investigating high-energy Hermite-Gauss and vortex laser generation in Alexandrite

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High Power Laser science and Engineering 2025年

作者： Cai, Enlin Zhang, Shuaiyi Li, Tao Wang, Jie Chen, Min Institute of Applied Physics Chinese Academy of Sciences Shanghai Shanghai China Advanced Research Institute Chinese Academy of Sciences Shanghai Shanghai China University of Chinese Academy of Sciences Beijing China Shandong Advanced Optoelectronic Materials and Technologies Engineering Laboratory School of Mathematics and Physics Qingdao University of Science & Technology Qingdao China School of Information Science and Engineering Shandong Provincial Key Laboratory of Laser Technology and Application Shandong University Qingdao China

This paper presents an investigation of the secondary saturation characteristics of a HfTe2 saturable absorber. Pulse energies of 5.85 mJ and 7.4 mJ were demonstrated with a highorder Hermite-Gaussian (HG) laser and a vortex laser, respectively, using Alexandrite as the gain medium. To the best of our knowledge, these are the highest pulse energies directly generated with HG and vortex lasers. To broaden the applications of high-energy pulsed HG and vortex lasers, wavelength tuning over a range of 40 nm was achieved using an etalon. © 2025 Cambridge University Press. All rights reserved.

关键词： Saturable absorbers

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NON-UNIQUENESS & INADMISSIBILITY OF THE VANISHING VISCOSITY LIMIT OF THE PASSIVE SCALAR TRANSPORT EQUATION

arXiv

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arXiv 2023年

作者： Huysmans, Lucas Titi, Edriss S. Department of Pure Mathematics & Mathematical Statistics University of Cambridge CambridgeCB3 0WB United Kingdom Department of Mathematics Texas A&M University College StationTX77840 United States Department of Applied Mathematics and Theoretical Physics University of Cambridge CambridgeCB3 0WA United Kingdom Department of Computer Science and Applied Mathematics Weizmann Institute of Science Rehovot76100 Israel

We study selection by vanishing viscosity for the transport of a passive scalar f(x, t) ∈ R advected by a bounded, divergence-free vector field u(x, t) ∈ R2. This is described by the initial value problem to the PDE ∂f /∂t + ∇ · (uf) = 0, or with positive viscosity/diffusivity ν > 0, to the PDE ∂f /∂t +∇·(uf)−ν∆f = 0. We demonstrate the failure of the vanishing viscosity limit to select (a) unique solutions or (b) physically admissible solutions in the sense of non-increasing energy/*** Codes 76F25 (Primary) 35A02, 35D30, 35Q35, 60J60, 76R10, 76R50 (Secondary) © 2023, CC BY.

关键词： Initial value problems

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Blockwise perturbative corrections in multiconfiguration calculations based on configuration-state-function generators: A revised analysis of the W xxxviii spectrum

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Physical Review A 2025年第4期111卷 042805-042805页

作者： Yanting Li Chaofan Shi Ran Si Kai Wang Per Jönsson Gediminas Gaigalas Michel Godefroid Chongyang Chen Shanghai EBIT Laboratory Key Laboratory of Nuclear Physics and Ion-beam Application Institute of Modern Physics Department of Nuclear Science and Technology Fudan University Shanghai 200433 China Department of Physics and Anhui Key Laboratory of Optoelectric Materials Science and Technology Key Laboratory of Functional Molecular Solids Ministry of Education Anhui Normal University Wuhu 241000 China Hebei Key Laboratory of Optic-Electronic Information and Materials The College of Physics Science and Technology Hebei University Baoding 071002 China Department of Materials Science and Applied Mathematics Malmö University SE-20506 Malmö Sweden Institute of Theoretical Physics and Astronomy Vilnius University 010222 Vilnius Lithuania Spectroscopy Quantum Chemistry and Atmospheric Remote Sensing Université Libre de Bruxelles Bruxelles Belgium

A methodology based on configuration-state-function generators (CSFGs) has recently been implemented in the General-Purpose Relativistic Atomic Structure Package (grasp) to reduce the computational load of configuration-interaction (CI) calculations Y. T. Li et al., Comput. Phys. Commun. 283, 108562 (2023). Large CI calculations can be performed if part of the interaction is treated perturbatively. Here, we present enhancements to the perturbative estimates by implementing blockwise methods, where the blocks are given by configuration-state-functions spanned by CSFGs. We compute excitation energies for 4s24p64d, 4s24p64f, and 4s24p54d2 states in Rb-like W37+ and corresponding transition wavelengths and rates to evaluate the methods. The final relative difference between calculated and experimental wavelengths is 0.01%. Thus, the calculations provide highly accurate values for W37+ properties useful for a variety of applications, including fusion applications.

关键词： Excitation energy

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Shedding Light on the Ageing of Extra Virgin Olive Oil: Probing the Impact of Temperature with Fluorescence Spectroscopy and Machine Learning Techniques

arXiv

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arXiv 2023年

作者： Venturini, Francesca Fluri, Silvan Mejari, Manas Baumgartner, Michael Piga, Dario Michelucci, Umberto Institute of Applied Mathematics and Physics Zurich University of Applied Sciences Technikumstrasse 9 Winterthur8401 Switzerland TOELT LLC Advanced AI Lab Birchlenstrasse 25 Dübendorf8600 Switzerland IDSIA - Dalle Molle Institute for Artificial Intelligence USI-SUPSI Via la Santa 1 Lugano6962 Switzerland Lucerne University of Applied Sciences and Arts Computer Science Department Lucerne Switzerland

This work systematically investigates the oxidation of extra virgin olive oil (EVOO) under accelerated storage conditions with UV absorption and total fluorescence spectroscopy. With the large amount of data collected, it proposes a method to monitor the oil’s quality based on machine learning applied to highly-aggregated data. EVOO is a high-quality vegetable oil that has earned worldwide reputation for its numerous health benefits and excellent taste. Despite its outstanding quality, EVOO degrades over time owing to oxidation, which can affect both its health qualities and flavour. Therefore, it is highly relevant to quantify the effects of oxidation on EVOO and develop methods to assess it that can be easily implemented under field conditions, rather than in specialized laboratories. The following study demonstrates that fluorescence spectroscopy has the capability to monitor the effect of oxidation and assess the quality of EVOO, even when the data are highly aggregated. It shows that complex laboratory equipment is not necessary to exploit fluorescence spectroscopy using the proposed method and that cost-effective solutions, which can be used in-field by non-scientists, could provide an easily-accessible assessment of the quality of EVOO. © 2023, CC BY-NC-ND.

关键词： Ultraviolet spectroscopy

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Massive fields in AdS from Constructive Holography

arXiv

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arXiv 2024年

作者： de Mello Koch, Robert Roy, Pratik Van Zyl, Hendrik J.R. School of Science Huzhou University Huzhou313000 China School of Physics and Mandelstam Institute for Theoretical Physics University of the Witwatersrand Wits2050 South Africa The Laboratory for Quantum Gravity & Strings Department of Mathematics & Applied Mathematics University of Cape Town Cape Town South Africa The National Institute for Theoretical and Computational Sciences Private Bag X1 Matieland South Africa

Collective field theory offers a constructive framework for exploring the AdS/CFT duality. In this article, we focus on constructing rotations within the light-front quantized collective field theory for the full set of spatial coordinates in the dual bulk AdS spacetime. Two intricate aspects require attention: how rotations involving the emergent holographic coordinate are implemented, and how rotations that involve the spatial coordinates participating in the construction of the light-cone coordinates X± are realized. Our construction is in agreement with Metsaev's construction directly in the gravity theory. Additionally, we derive the eigenfunctions of the AdS mass operator, which dictate the GKPW rule for the emergent higher-dimensional theory. Copyright © 2024, The Authors. All rights reserved.

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Measurement of differential cross sections of neutron-induced deuteron production reactions on carbon from 25 to 52 MeV

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Chinese physics C 2021年第6期45卷 109-120页

作者： Zengqi Cui Haoyu Jiang Kang Sun Guohui Zhang Ruirui Fan Wei Jiang Huaiyong Bai Yiwei Hu Jie Liu Han Yi Changjun Ning Zhijia Sun Jingyu Tang Qi An Jie Bao Yu Bao Ping Cao Haolei Chen Qiping Chen Yonghao Chen Yukai Chen Zhen Chen Changqing Feng Keqing Gao Minhao Gu Changcai Han Zijie Han Guozhu He Yongcheng He Yang Hong Hanxiong Huang Weiling Huang Xiru Huang Xiaolu Ji Xuyang Ji Zhijie Jiang Hantao Jing Ling Kang Mingtao Kang Bo Li Chao Li Jiawen Li Lun Li Qiang Li Xiao Li Yang Li Rong Liu Shubin Liu Xingyan Liu Guangyuan Luan Qili Mu Binbin Qi Jie Ren Zhizhou Ren Xichao Ruan Zhaohui Song Yingpeng Song Hong Sun Xiaoyang Sun Zhixin Tan Hongqing Tang Xinyi Tang Binbin Tian Lijiao Wang Pengcheng Wang Qi Wang Taofeng Wang Zhaohui Wang Jie Wen Zhongwei Wen Qingbiao Wu Xiaoguang Wu Xuan Wu Likun Xie Yiwei Yang Li Yu Tao Yu Yongji Yu Linhao Zhang Qiwei Zhang Xianpeng Zhang Yuliang Zhang Zhiyong Zhang Yubin Zhao Luping Zhou Zuying Zhou Danyang Zhu Kejun Zhu Peng Zhu State Key Laboratory of Nuclear Physics and Technology School of PhysicsPeking UniversityBeijing 100871China Institute of High Energy Physics Chinese Academy of Sciences(CAS)Beijing 100049China Spallation Neutron Source Science Center Dongguan 523803China University of Chinese Academy of Sciences Beijing 100049China State Key Laboratory of Particle Detection and Electronics Department of Modern Physics University of Science and Technology of ChinaHefei 230026China Key Laboratory of Nuclear Data China Institute of Atomic EnergyBeijing 102413China Institute of Nuclear Physics and Chemistry China Academy of Engineering PhysicsMianyang 621900China Northwest Institute of Nuclear Technology Xi'an 710024China Department of Engineering and Applied Physics University of Science and Technology of ChinaHefei 230026China School of Physics Beihang UniversityBeijing 100083China

The angle-differential cross sections of neutron-induced deuteron production from carbon were measured at six neutron energies from 25 to 52 MeV relative to those of n-p elastic scattering at the China Spallation Neutron Source(CSNS)Back-n white neutron *** employing theΔE-E telescopes of the Light-charged Particle Detector Array(LPDA)system at 15.1°to 55.0°in the laboratory system,ratios of the angle-differential cross sections of the ^(12)C(n,xd)reactions to those of the n-p scattering were measured,and then,the angle-differential cross sections of the ^(12)C(n,xd)reactions were obtained using the angle-differential cross sections of the n-p elastic scattering from the JENDL-4.0/HE-2015 library as the *** obtained results are compared with data from previous measurements,all of which are based on mono-energic neutrons,the evaluated data from the JENDL-4.0/HE-2015 library and the ENDF-B/VIII.0 library,and those from theoretical calculations based on INCA code and Talys-1.9 *** the first white-neutron-source-based systematic measurement of the angle-differential cross sections of neutron-induced deuteron production reactions on carbon in several tens of MeV,the present work can provide a reference to the data library considering the lack of experimental data.

关键词： ^(12)C(n,xd)reactions relative angle-differential cross sections CSNS Back-n white neutron source LPDA

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Strong Polarization of a J=1/2 to 1/2 Transition Arising from Unexpectedly Large Quantum Interference

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Physical Review Letters 2023年第11期130卷 113001-113001页

作者： Nobuyuki Nakamura Naoki Numadate Simpei Oishi Xiao-Min Tong Xiang Gao Daiji Kato Hirokazu Odaka Tadayuki Takahashi Yutaka Tsuzuki Yuusuke Uchida Hirofumi Watanabe Shin Watanabe Hiroki Yoneda Institute for Laser Science The University of Electro-Communications Tokyo 182-8585 Japan Center for Computational Sciences University of Tsukuba Ibaraki 305-8573 Japan Institute for Applied Physics and Computational Mathematics Beijing 100088 China National Institute for Fusion Science Toki Gifu 509-5292 Japan Interdisciplinary Graduate School of Engineering Sciences Kyushu University Fukuoka 816-8580 Japan Department of Physics The University of Tokyo Tokyo 113-0033 Japan Kavli Institute for the Physics and Mathematics of the Universe (WPI) Institutes for Advanced Study (UTIAS) The University of Tokyo Chiba 277-8583 Japan Department of Physics School of Science and Technology Tokyo University of Science Chiba 278-8510 Japan Center of Applied Superconductivity and Sustainable Energy Research Chubu University Aichi 487-8501 Japan Institute of Space and Astronautical Science Japan Aerospace Exploration Agency Kanagawa 252-5210 Japan RIKEN Nishina Center Saitama 351-0198 Japan

We experimentally show that the 1s22s22p1/2−1s2s22p1/22 transition in Pb77+ emitted in dielectronic recombination of Pb78+ is strongly polarized, although it is an intrinsically unpolarized J=1/2 to 1/2 transition. This unanticipated polarization is shown to be due to quantum interference with radiative recombination. The interference effect has been studied on an asymmetric resonance profile but has never been studied on polarization. In this Letter, we show that the effect on polarization can arise from a different cross term than that responsible for asymmetry, resulting in unexpectedly large polarization even for a nearly symmetric resonance suggesting a small interference.

关键词： Relativistic & quantum electrodynamic effects in atoms, molecules,& ions Relativistic heavy-ion collisions Ions Polarization

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Molecule opacities of X^2Σ^+, A^2Π, and B^2Σ^+ states of CS^+

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Chinese physics B 2019年第5期28卷 64-70页

作者： Xiao-He Lin Gui-Ying Liang Jian-Guo Wang Yi-Geng Peng Bin Shao Rui Li Yong Wu School of Physics Beijing Institute of Technology Institute of Applied Physics and Computational Mathematics Department of Physics College of Science Qiqihar University HEDPS Center for Applied Physics and Technology Peking University

Carbon sulfide cation(CS^+) plays a dominant role in some astrophysical atmosphere environments. In this work, the rovibrational transition lines are computed for the lowest three electronic states, in which the internally contracted multireference configuration interaction approach(MRCI) with Davison size-extensivity correction(+Q) is employed to calculate the potential curves and dipole moments, and then the vibrational energies and spectroscopic constants are extracted. The Frank–Condon factors are calculated for the bands of X^2^+Σ^+–A^2Π and X^2Σ^+–B^2Σ^+systems, and the band of X^2Σ^+–A^2Π is in good agreement with the available experimental results. Transition dipole moments and the radiative lifetimes of the low-lying three states are evaluated. The opacities of the CS^+ molecule are computed at different temperatures under the pressure of 100 atms. It is found that as temperature increases, the band systems associated with different transitions for the three states become dim because of the increased population on the vibrational states and excited electronic states at high temperature.

关键词： CS^+ dipole moment transition dipole moment opacity

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Micromagnetic Simulations of Nanoparticles with Varying Amount of Agglomeration

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Macromolecular Symposia 2022年第1期402卷

作者： Blachowicz, Tomasz Grzybowski, Jacek Ehrmann, Andrea Institute of Physics – Centre for Science and Education Silesian University of Technology Gliwice44-100 Poland Faculty of Engineering and Mathematics Bielefeld University of Applied Sciences Bielefeld33619 Germany

Magnetic nanoparticles can be used for medical and other purposes, but can also be integrated in polymeric or other nonmagnetic matrices of diverse shapes, for example, thin-films or fibers. In the latter case, it may be important how the magnetic nanoparticles are distributed in the matrix, a topic which is often not taken into account when such composites are investigated experimentally or theoretically. Especially for small magnetic nanoparticles of dimensions allowing coherent reversal, the magnetic properties of such polymer/magnet composites can change drastically in the case of agglomerations. Here, a method is suggested to quantify the influence of nanoparticle distributions inside nonmagnetic matrices. By changing the average distance between nanoparticles of varying diameters between highly distributed particles and perfectly packed clusters, different magnetization dynamics can be modeled by micromagnetic simulations. Here, this process is shown for various magnetic materials and diameter distributions of magnetic nano-spheres and present corresponding micromagnetic simulation results, which underline the importance of taking into account possible magnetic agglomerations in nonmagnetic space. © 2022 The Authors. Macromolecular Symposia published by Wiley-VCH GmbH.

关键词： Spheres

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