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Physical Review A 2021年第3期103卷 033111-033111页

作者： Yuna Yang Mingqing Liu Xiaolei Hao Jing Chen Institute of Applied Physics and Computational Mathematics Beijing 100088 China College of Science Tianjin University of Technology Tianjin 300384 China Institute of Theoretical Physics and Department of Physics State Key Laboratory of Quantum Optics and Quantum Optics DevicesCollaborative Innovation Center of Extreme Optics Shanxi University Taiyuan 030006 China Center for Advanced Material Diagnostic Technology Shenzhen Technology University Shenzhen 518118 China

Based on the strong-field approximation (SFA), we investigate the interference between different returning orbits of the rescattering electron in nonsequential double ionization. We find that the effect of interference is negligible in the recollision-impact ionization process but is prominent in the recollision excitation with subsequent ionization process and induces fast oscillation with constant period in the laser intensity dependence of the asymmetry parameter. The dominant contribution to the fast oscillation comes from the mixed interference between different pairs of returning orbits in different excitation channels. However, the oscillation disappears after laser focus averaging is performed due to its rather small period.

关键词： Atomic & molecular processes in external fields Multiphoton or tunneling ionization & excitation

Obstacles on the Pathway Towards Chemical programmability Using Agglomerations of Droplets 15th

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Obstacles on the Pathway Towards Chemical Programmability Us...

15th International Workshop on Artificial Life and Evolutionary Computation, WIVACE 2021

作者： Schneider, Johannes Josef Faggian, Alessia Matuttis, Hans-Georg Barrow, David Anthony Li, Jin Holler, Silvia Casiraghi, Federica Sanahuja, Lorena Cebolla Hanczyc, Martin Michael Eschle, Patrik Weyland, Mathias Sebastian Flumini, Dandolo Eggenberger Hotz, Peter Füchslin, Rudolf Marcel Institute of Applied Mathematics and Physics School of Engineering Zurich University of Applied Sciences Technikumstr. 9 Winterthur8401 Switzerland Laboratory for Artificial Biology Department of Cellular Computational and Integrative Biology University of Trento Via Sommarive 9 Povo38123 Italy Department of Mechanical Engineering and Intelligent Systems The University of Electrocommunications Chofu Chofugaoka 1-5-1 Tokyo182-8585 Japan Laboratory for Microfluidics and Soft Matter Microengineering Cardiff School of Engineering Cardiff University Queen’s Buildings 14-17 The Parade CardiffCF24 3AA United Kingdom Chemical and Biological Engineering University of New Mexico MSC01 1120 AlbuquerqueNM87131-0001 United States European Centre for Living Technology Ca’ Bottacin Dorsoduro 3911 Calle Crosera Venice30123 Italy

ISBN: (纸本)9783031239281

We aim at planning and creating specific agglomerations of droplets to study synergic communication using these as programmable units. In this paper, we give an overview of preliminary obstacles for the various research issues, namely of how to create droplets, how to set up droplet agglomerations using DNA technology, how to prepare them for confocal microscopy, how to make a computer see droplets on photos, how to analyze networks of droplets, how to perform simulations mimicking experiments, and how to plan specific agglomerations of droplets. © 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG.

关键词： Drops

Super-Resolution without High-Resolution Labels for Black Hole Simulations

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arXiv 2024年

作者： Helfer, Thomas Edwards, Thomas D.P. Dafflon, Jessica Wong, Kaze W.K. Olson, Matthew Lyle Institute for Advanced Computational Science Stony Brook University Stony BrookNY11794 United States William H. Miller III Department of Physics and Astronomy Johns Hopkins University BaltimoreMD21218 United States Valence Labs 6666 Rue Saint-Urbain MontrealQCH2S 3H1 Canada Department of Applied Mathematics and Statistics Johns Hopkins University BaltimoreMD21218 United States Data Science and AI Institute Johns Hopkins University BaltimoreMD21218 United States Center for Computational Astrophysics Flatiron Institute New YorkNY10010 United States Intel Labs Santa ClaraCA United States

Generating high-resolution simulations is key for advancing our understanding of one of the universe's most violent events: Black Hole mergers. However, generating Black Hole simulations is limited by prohibitive computational costs and scalability issues, reducing the simulation's fidelity and resolution achievable within reasonable time frames and resources. In this work, we introduce a novel method that circumvents these limitations by applying a super-resolution technique without directly needing high-resolution labels, leveraging the Hamiltonian and momentum constraints-fundamental equations in general relativity that govern the dynamics of spacetime. We demonstrate that our method achieves a reduction in constraint violation by one to two orders of magnitude and generalizes effectively to out-of-distribution simulations. Copyright © 2024, The Authors. All rights reserved.

关键词： Black holes

Autonomous Electron Tomography Reconstruction with Machine Learning

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arXiv 2023年

作者： Millsaps, William Schwartz, Jonathan Di, Zichao Wendy Jiang, Yi Hovden, Robert Department of Nuclear Engineering & Radiological Sciences University of Michigan Ann ArborMI United States Department of Materials Science and Engineering University of Michigan Ann ArborMI United States Mathematics and Computer Science Division Argonne National Laboratory LemontIL United States Advanced Photon Source Facility Argonne National Laboratory LemontIL United States Applied Physics Program University of Michigan Ann ArborMI United States

This manuscript is published in Microscopy and Microanalysis (DOI: 10.1093/micmic/ozad083). Modern electron tomography has progressed to higher resolution at lower doses by leveraging compressed sensing methods that minimize total variation (TV). However, these sparsity-emphasized reconstruction algorithms introduce tunable parameters that greatly influence the reconstruction quality. Here, Pareto front analysis shows that high-quality tomograms are reproducibly achieved when TV minimization is heavily weighted. However, in excess, compressed sensing tomography creates overly smoothed 3D reconstructions. Adding momentum to the gradient descent during reconstruction reduces the risk of over-smoothing and better ensures that compressed sensing is well behaved. For simulated data, the tedious process of tomography parameter selection is efficiently solved using Bayesian optimization with Gaussian processes. In combination, Bayesian optimization with momentum-based compressed sensing greatly reduces the required compute time-an 80% reduction was observed for the 3D reconstruction of SrTiO3 nanocubes. Automated parameter selection is necessary for large scale tomographic simulations that enable the 3D characterization of a wider range of inorganic and biological materials. © 2023, CC BY.

关键词： Compressed sensing

ALTERNATING DIRECTION IMPLICIT OSC SCHEME FOR THE TWO-DIMENSIONAL FRACTIONAL EVOLUTION EQUATION WITH A WEAKLY SINGULAR KERNEL

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Acta Mathematica Scientia 2018年第6期38卷 1689-1711页

作者： Haixiang ZHANG Xuehna YANG Da XU Laboratory of Computational Physics Institute of Applied Physics and Computational Mathematics School of Science Hunan University of Technology Department of Mathematics Hunan Normal University

In this paper, a new kind of alternating direction implicit （ADI） Crank-Nicolson-type orthogonal spline collocation （OSC） method is formulated for the two-dimensional frac-tional evolution equation with a weakly singular kernel arising in the theory of linear viscoelas-ticity. The novel OSC method is used for the spatial discretization, and ADI Crank-Nicolson-type method combined with the second order fractional quadrature rule are considered for thetemporal component. The stability of proposed scheme is rigourously established, and nearlyoptimal order error estimate is also derived. Numerical experiments are conducted to supportthe predicted convergence rates and also exhibit expected super-convergence phenomena.

关键词： fractional equation orthogonal spline collocation scheme alternating directionimplicit stability convergence

β-decay feeding intensity distribution of Mn64

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Physical Review C 2024年第4期109卷 044312-044312页

作者： W. W. von Seeger P. A. DeYoung A. Spyrou S. Karampagia E. F. Brown S. Ahn B. P. Crider A. C. Dombos G. W. Hitt C. Langer R. Lewis S. N. Liddick S. Lyons Z. Meisel F. Montes F. Naqvi W.-J. Ong C. F. Persch J. Pereira H. Schatz K. Schmidt Department of Physics Hope College Holland Michigan 49423 USA Department of Physics and Astronomy Michigan State University East Lansing Michigan 48824 USA Facility for Rare Isotope Beams Michigan State University East Lansing Michigan 48824 USA Joint Institute for Nuclear Astrophysics–Center for the Evolution of the Elements Michigan State University East Lansing Michigan 48824 USA Grand Valley State University Allendale Michigan 49401 USA Department of Computational Mathematics Science and Engineering Michigan State University East Lansing Michigan 48824 USA Cyclotron Institute Texas A&M University College Station Texas 77843 USA Center for Exotic Nuclear Studies Institute for Basic Science Daejon 34126 South Korea Department of Physics and Astronomy Mississippi State University Mississippi State Mississippi 39762 USA Department of Physics and Engineering Science Coastal Carolina University Conway South Carolina 29528 USA University of Applied Sciences Aachen 52066 Aachen Germany Department of Chemistry Michigan State University East Lansing Michigan 48824 USA Department of Physics and Astronomy Ohio University Athens Ohio 45701 USA Department of Nuclear Engineering Texas A&M University College Station Texas 77840 USA Nuclear and Chemical Sciences Division Lawrence Livermore National Laboratory Livermore California 94550 USA Institute of Radiation Physics Helmholtz-Zentrum Dresden-Rossendorf Bautzner Landstrasse 400 01328 Dresden Germany

Nuclei around the N=40 “island of inversion” exhibit interesting structure features that have been the focus of several experimental and theoretical studies. The present work presents the first complete study of the β-decay feeding intensity distribution and Gamow-Teller distribution for the β decay of Mn64 to Fe64 up to ≈10 MeV. The β-decay intensity function was extracted from total absorption spectroscopy measurements made at the National Superconducting Cyclotron Laboratory with the Summing NaI(Tl) (SuN) detector. The experimental results are compared to shell model calculations with and without the inclusion of the νg9/2 orbital. From this comparison it is clear that the νg9/2 orbital is essential for the accurate description of the Fe64β-decay strength above ≈3 MeV, emphasizing once again the transitional nature of this nucleus into the N=40 island of inversion.

关键词： Beta decay Collective levels Nuclear structure & decays Shell model 59 ≤ A ≤ 89 Spectrometers & spectroscopic techniques

Ill-posedness for the Cauchy problem of the Camassa-Holm equation in B1∞,1(R)

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arXiv 2021年

作者： Guo, Yingying Ye, Weikui Yin, Zhaoyang School of Mathematics and Big Data Foshan University Foshan528000 China Institute of Applied Physics and Computational Mathematics P.O. Box 8009 Beijing100088 China Department of Mathematics Sun Yat-sen University Guangzhou510275 China Faculty of Information Technology Macau University of Science and Technology China

For the famous Camassa-Holm equation, the well-posedness in Bp1+1/p1 (R) with p ∈ [1, ∞) and the ill-posedness in Bp,r1+1/p (R) with p ∈ [1, ∞], r ∈ (1, ∞] had been studied in [13, 14, 16, 23], that is to say, it only left an open problem in the critical case B1∞,1(R) proposed by Danchin in [13, 14]. In this paper, we solve this problem by proving the norm inflation and hence the ill-posedness for the Camassa-Holm equation in B∞1,1(R). Therefore, the well-posedness and ill-posedness for the Camassa-Holm equation in all critial Besov spaces Bp,11+1/p (R) with p ∈ [1, ∞] have been completed. Finally, since the norm inflation occurs by choosing an special initial data u0 ∈ B1∞,1(R) but u20x ∈/ B0∞,1(R) (an example implies B0∞,1(R) is not a Banach algebra), we then prove that this condition is necessary. That is, if u20x ∈ B0∞,1(R) holds, then the Camassa-Holm equation has a unique solution u(t, x) ∈ CT (B1∞,1(R)) ∩ CT1 (B0∞,1(R)) and the norm inflation will not *** Codes 35Q35, 35G25, 35L30 Copyright © 2021, The Authors. All rights reserved.

关键词： Banach spaces

Uniaxial plasmon polaritons via charge transfer at the graphene/CrSBr interface

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arXiv 2024年

作者： Rizzo, Daniel J. Seewald, Eric Zhao, Fangzhou Cox, Jordan Xie, Kaichen Vitalone, Rocco A. Ruta, Francesco L. Chica, Daniel G. Shao, Yinming Shabani, Sara Telford, Evan J. Strasbourg, Matthew C. Darlington, Thomas P. Xu, Suheng Qiu, Siyuan Devarakonda, Aravind Taniguchi, Takashi Watanabe, Kenji Zhu, Xiaoyang Schuck, P. James Dean, Cory R. Roy, Xavier Millis, Andrew J. Cao, Ting Rubio, Angel Pasupathy, Abhay N. Basov, D.N. Department of Physics Columbia University New YorkNY10027 United States Department of Applied Physics and Applied Mathematics Columbia University New YorkNY10027 United States Theory Department Max Planck Institute for Structure and Dynamics of Matter Center for Free-Electron Laser Science Hamburg22761 Germany Department of Chemistry Columbia University New YorkNY10027 United States Department of Materials Science and Engineering University of Washington SeattleWA98195 United States Department of Mechanical Engineering Columbia University New YorkNY10027 United States Research Center for Materials Nanoarchitectonics National Institute for Materials Science 1-1 Namiki Tsukuba305-0044 Japan Research Center for Electronic and Optical Materials National Institute for Materials Science 1-1 Namiki Tsukuba305-0044 Japan Center for Computational Quantum Physics Flatiron Institute New YorkNY10010 United States Nano-Bio Spectroscopy Group Universidad del País Vasco UPV/EHU San Sebastián20018 Spain

Graphene is a privileged 2D platform for hosting confined light-matter excitations known as surface plasmon-polaritons (SPPs), as it possesses low intrinsic losses with a high degree of optical confinement. However, the inherently isotropic optical properties of graphene limit its ability to guide and focus SPPs, making it less suitable than anisotropic elliptical and hyperbolic materials as a platform for polaritonic lensing and canalization. Here, we present the graphene/CrSBr heterostructure as an engineered 2D interface that hosts highly anisotropic SPP propagation over a wide range of frequencies in the mid-infrared and terahertz. Using a combination of scanning tunneling microscopy (STM), scattering-type scanning near-field optical microscopy (s-SNOM), and first-principles calculations, we demonstrate mutual doping in excess of 1013 cm–2 holes/electrons between the interfacial layers of graphene/CrSBr heterostructures. SPPs in graphene activated by charge transfer interact with charge-induced anisotropic intra- and interband transitions in the interfacial doped CrSBr, leading to preferential SPP propagation along the quasi-1D chains that compose each CrSBr layer. This multifaceted proximity effect both creates SPPs and endows them with anisotropic transport and propagation lengths that differ by an order-of-magnitude between the two in-plane crystallographic axes of CrSBr. © 2024, CC BY.

关键词： Charge transfer

Coupling effects and thin-shell corrections for surface instabilities of cylindrical fluid shells

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Physical Review E 2020年第2期101卷 023108-023108页

作者： Shuai Zhang Hao Liu Wei Kang Zuoli Xiao Jianjun Tao Ping Zhang Weiyan Zhang X. T. He HEDPS Center for Applied Physics and Technology and College of Engineering Peking University Beijing 100871 China Department of Applied Physics School of Physics and Electronics Hunan University Changsha 410082 China Department of Mechanics and Engineering Science College of Engineering Peking University Beijing 100871 China Institute of Applied Physics and Computational Mathematics Beijing 100088 China China Academy of Engineering Physics Mianyang 621900 China

We show that when linear azimuthal perturbations on the surfaces of a fluid shell are regrouped according to αm, they can be divided into Bell model terms, coupling terms, and the newly identified thin-shell correction terms, where α is the ratio of Rout to Rin, and m is the mode number of a given unstable mode on the surfaces. It is also revealed that αm is a convenient index variable of coupling effects, with which we show that the evolution of instability is composed of three stages, i.e., strongly coupled stage, transition stage, and uncoupled stage. Roughly, when αm<6, the fluid shell is in the strongly coupled stage, where both coupling effects and the newly identified thin-shell corrections play important roles. Strong feed through is expected to be observed. The uncoupled stage is reached at αm∼36, where Bell's model of independent surface holds. In between is the transition stage, where mode competitions on the two surfaces are expected to be observed. These results afford an intuitive picture which is easy to use in guiding the design of experiments. They may also help to quickly grasp major features of instability experiments of this kind.

关键词： Flow instability High-energy-density plasmas Implosion symmetry Inertial confinement fusion Instability of free-surface flows Rayleigh-Taylor instability Target design & fabrication

Isotope effects in molecular structures and electronic properties of liquid water via deep potential molecular dynamics based on the SCAN functional

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Physical Review B 2020年第21期102卷 214113-214113页

作者： Jianhang Xu Chunyi Zhang Linfeng Zhang Mohan Chen Biswajit Santra Xifan Wu Department of Physics Temple University Philadelphia Pennsylvania 19122 USA Program in Applied and Computational Mathematics Princeton University Princeton New Jersey 08544 USA CAPT HEDPS College of Engineering Peking University Beijing 100871 China Institute for Computational Molecular Science Temple University Philadelphia Pennsylvania 19122 USA

Feynman path-integral deep potential molecular dynamics (PI-DPMD) calculations have been employed to study both light (H2O) and heavy water (D2O) within the isothermalisobaric ensemble. In particular, the deep neural network is trained based on ab initio data obtained from the strongly constrained and appropriately normed (SCAN) exchange-correlation functional. Because of the lighter mass of hydrogen than deuteron, the properties of light water are more influenced by nuclear quantum effect than those of heavy water. Clear isotope effects are observed and analyzed in terms of hydrogen-bond structure and electronic properties of water that are closely associated with experimental observables. The molecular structures of both liquid H2O and D2O agree well with the data extracted from scattering experiments. The delicate isotope effects on radial distribution functions and angular distribution functions are well reproduced as well. Our approach demonstrates that deep neural network combined with SCAN functional based ab initio molecular dynamics provides an accurate theoretical tool for modeling water and its isotope effects.

关键词： Atomic & molecular structure Electronic structure Isotope effect Water Ab initio calculations Density functional theory Machine learning Molecular dynamics Path-integral methods