检索结果-内蒙古大学图书馆

Observation of the interaction between Au− and CO2 in Au(CO2)n− anions: Physisorption as the dominant mechanism

学校读者我要写书评

暂无评论

Journal of Chemical physics 2025年第17期162卷 174310页

作者： Guo, Zonghui Du, Shihu Huang, Wei Zhao, Wenbao Han, Haiyan Zhao, Zhi Yan, Yongliang Fan, Zhihui Shi, Ruili Xie, Hua Jiang, Ling School of Mathematics and Physics Science and Engineering Hebei Computational Optical Imaging and Photoelectric Detection Technology Innovation Center Hebei International Joint Research Center for Computational Optical Imaging and Intelligent Sensing Hebei University of Engineering Handan056038 China School of Chemistry and Chemical Engineering Shandong University Jinan250100 China State Key Laboratory of Molecular Reaction Dynamics Dalian Institute of Chemical Physics Chinese Academy of Sciences Dalian116023 China

In this study, we investigated the structure and bonding of Au(CO2)n− (n = 2, 3) using photoelectron spectroscopy analysis, quantum chemical calculations, and weak interaction analysis. Quantum chemical calculations revealed that the geometries of the physisorbed structures closely aligned with experimental data, suggesting that these configurations were the most stable under the experimental conditions. Conversely, while chemisorbed structures exhibit stronger interactions and considerable CO2 activation, they show less agreement with the observed spectroscopic data. Using the interaction region indicator method, our weak interaction analysis confirmed that van der Waals forces were the dominant interaction in the physisorbed structures. Our experimental results indicate that these physically adsorbed structures are more stable under the conditions of this study. These findings shed light on the interaction mechanisms of Au(CO2)n− (n = 2, 3) at the molecular level and provide new insights into the potential for transition metals to catalytically activate CO2 © 2025 Author(s).

关键词： Van der Waals forces

Supersonic flow kinetics: Mesoscale structures, thermodynamic nonequilibrium effects and entropy production mechanisms

学校读者我要写书评

暂无评论

arXiv 2025年

作者： Gan, Yanbiao Zhuang, Zhaowen Yang, Bin Xu, Aiguo Zhang, Dejia Chen, Feng Song, Jiahui Wu, Yanhong Hebei Key Laboratory of Trans-Media Aerial Underwater Vehicle North China Institute of Aerospace Engineering Langfang065000 China School of Energy and Safety Engineering Tianjin Chengjian University Tianjin300384 China National Key Laboratory of Computational Physics Institute of Applied Physics and Computational Mathematics P. O. Box 8009-26 Beijing100088 China National Key Laboratory of Shock Wave and Detonation Physics Mianyang621999 China HEDPS Center for Applied Physics and Technology College of Engineering Peking University Beijing100871 China State Key Laboratory of Explosion Science and Technology Beijing Institute of Technology Beijing100081 China School of Physical Science and Technology Guangxi University Nanning530004 China School of Aeronautics Shan Dong Jiaotong University Jinan250357 China School of Aerospace Engineering Beijing Institute of Technology Beijing100081 China

Supersonic flow is a typical nonlinear, nonequilibrium, multiscale, and complex phenomenon. Compared to scenarios described by Navier-Stokes (NS) theory, mesoscale behavior in supersonic flow exhibits greater discreteness and a higher degree of nonequilibrium. Meanwhile, the entropy production mechanism, which involves compression efficiency and the ability to perform external work, is a significant focus in supersonic flow fields. As the degree of discrete/nonequilibrium effects increases, the study of entropy production based on NS theory may need reevaluation and appropriate revision. To address these issues, this paper develops and applies the discrete Boltzmann modeling and analysis method/model (DBM), based on kinetic and mean-field theories, to simulate, and analyze these phenomena. The study provides the following results: A Burnett-level DBM suitable for supersonic flow is constructed based on the Shakhov-BGK model. Higher-order analytical expressions for typical thermodynamic nonequilibrium effects are derived, providing a constitutive basis for improving traditional macroscopic hydrodynamics modeling. Criteria for evaluating the validity of DBM are established by comparing numerical and analytical solutions of nonequilibrium effects. The multiscale DBM is used to investigate discrete/nonequilibrium characteristics and entropy production mechanisms in shock regular reflection. The findings include: (a) Compared to the NS-level DBM, the Burnett-level DBM offers more accurate representations of viscous stress and heat flux, i.e., more precise dissipative mechanisms, ensures non-negativity of entropy production in accordance with the second law of thermodynamics, and exhibits better numerical stability. (b) Near the interfaces of incident and reflected shock waves, strong nonequilibrium driving forces lead to prominent nonequilibrium effects. By monitoring the timing and location of peak nonequilibrium quantities, the evolution characteristics of incident and

关键词： Supersonic flow

Local doping of an oxide semiconductor by voltage-driven splitting of anti-Frenkel defects

学校读者我要写书评

暂无评论

arXiv 2025年

作者： He, Jiali Ludacka, Ursula Hunnestad, Kasper A. Småbråten, Didrik R. Shapovalov, Konstantin Vullum, Per Erik Hatzoglou, Constantinos Evans, Donald M. Roede, Erik D. Yan, Zewu Bourret, Edith Selbach, Sverre M. Gao, David Akola, Jaakko Meier, Dennis Department of Materials Science and Engineering NTNU Norwegian University of Science and Technology Trondheim Norway Department of Electronic Systems NTNU Norwegian University of Science and Technology Trondheim Norway Department of Sustainable Energy Technology SINTEF Industry Oslo Norway Theoretical Materials Physics Q-MAT University of Liège Sart-Tilman B-4000 Belgium SINTEF Industry Trondheim Norway Department of Physics ETH Zürich Zürich Switzerland Materials Sciences Division Lawrence Berkeley National Laboratory Berkeley United States Department of Physics NTNU Norwegian University of Science and Technology Trondheim Norway Nanolayers Research Computing London United Kingdom Computational Physics Laboratory Tampere University Tampere Finland

Layered oxides exhibit high ionic mobility and chemical flexibility, attracting interest as cathode materials for lithium-ion batteries and the pairing of hydrogen production and carbon capture. Recently, layered oxides emerged as highly tunable semiconductors. For example, by introducing anti-Frenkel defects, the electronic hopping conductance in hexagonal manganites was increased locally by orders of magnitude. Here, we demonstrate local acceptor and donor doping in Er(Mn,Ti)O3, facilitated by the splitting of such anti-Frenkel defects under applied d.c. voltage. By combining density functional theory calculations, scanning probe microscopy, atom probe tomography, and scanning transmission electron microscopy, we show that the oxygen defects readily move through the layered crystal structure, leading to nano-sized interstitial-rich (p-type) and vacancy-rich (n-type) regions. The resulting pattern is comparable to dipolar npn-junctions and stable on the timescale of days. Our findings reveal the possibility of temporarily functionalizing oxide semiconductors at the nanoscale, giving additional opportunities for the field of oxide electronics and the development of transient electronics in general. © 2025, CC BY.

关键词： Oxide semiconductors

Enhancing electron transport for efficiency -recorded HTL-free inverted perovskite solar cells by molecular complementary passivation

学校读者我要写书评

暂无评论

Joule 2025年

作者： Cai, Qingbin Tan, Qin He, Jiacheng Tang, Siyuan Sun, Qiang He, Dong Cheng, Tianle Ma, Guoqiang Huang, Jinfeng Su, Gangsen Chen, Chuanxin Gu, Hao Wang, Bingzhe Fan, Jing Xing, Guichuan He, Zhubing No. 1088 Xueyuan Road Guangdong Shenzhen518055 China Joint Key Laboratory of the Ministry of Education Institute of Applied Physics and Materials Engineering University of Macau Avenida da Universidade Macau Taipa999078 China Center for Computational Science and Engineering Southern University of Science and Technology No. 1088 Xueyuan Road Guangdong Shenzhen518055 China

Inverted perovskite solar cells without pre-depositing a layer of hole-transport materials (HTL-free PSCs) still suffer from the non-irradiative recombination at the perovskite/electron-transport layer (ETL) interface. In this work, we report a molecular complementary passivation (MCP) strategy by employing propylphosphonic acid 3-ammonium bromide (PPAABr) to cooperate with phenethylammonium bromide (PEABr) to mutually passivate surface defects of I and formamidinium (FA) vacancies by multi-coordination. This passivation led to an obvious decrease in interfacial defect-state density and greatly improved exciton and carrier lifetime for the perovskite film. Moreover, MCP surface treatment pushes the perovskite surface Fermi level closer to that of ETL, thereby enhancing interfacial electron extraction. As a result, MCP-based HTL-free PSC achieved a record efficiency of 26.40% (25.92% certified). The encapsulated device retains 94.8% of its initial efficiency after 1,000 h of light soaking. The generality of the MCP strategy also generated a competitive efficiency of 23.66% for 1.68 eV wide-band-gap PSCs. © 2025 Elsevier Inc.

关键词： Energy gap

Multiscale thermodynamic nonequilibrium effects in Kelvin-Helmholtz instability and their relative importance

学校读者我要写书评

暂无评论

arXiv 2025年

作者： He, Zhongyi Gan, Yanbiao Yang, Bin Li, Demei Lai, Huilin Xu, Aiguo Fujian Normal University Fuzhou350117 China Hebei Key Laboratory of Trans-Media Aerial Underwater Vehicle North China Institute of Aerospace Engineering Langfang065000 China School of Energy and Safety Engineering Tianjin Chengjian University Tianjin300384 China National Key Laboratory of Computational Physics Institute of Applied Physics and Computational Mathematics P. O. Box 8009-26 Beijing100088 China National Key Laboratory of Shock Wave and Detonation Physics Mianyang621999 China HEDPS Center for Applied Physics and Technology College of Engineering Peking University Beijing100871 China State Key Laboratory of Explosion Science and Safety Protection Beijing Institute of Technology Beijing100081 China

This study investigates the complex kinetics of thermodynamic nonequilibrium effects (TNEs) and their relative importance during the development of the Kelvin-Helmholtz instability (KHI) using high-order discrete Boltzmann models (DBMs). First, the capabilities and differences among various discrete velocity sets in capturing TNEs and distribution functions are assessed. Based on this analysis, practical guidelines for constructing discrete velocity stencils are proposed to enhance phase-space discretization and improve the robustness of high-order DBM simulation. At different stages of KHI and under varying initial conditions, multiscale TNEs, such as viscous stresses of different orders, emerge with distinct dominant roles. Specifically, three scenarios are identified: (i) regimes dominated by first-order TNEs, (ii) alternation between first- and second-order TNEs, and (iii) states where second-order TNEs govern the system’s behavior. To quantitatively capture these transitions, criteria for TNE dominance at different orders in KHI evolution are established based on the relative thermodynamic nonequilibrium intensity (RTNE). In scenarios dominated by second-order TNEs, differences between first-order and second-order models are compared in terms of macroscopic quantities, nonequilibrium effects, and kinetic moments, revealing the physical limitations of low-order models in capturing TNEs. Furthermore, the effectiveness, extensibility, and limitations of a representative high-order model are examined under second-order TNE-dominated conditions. To encapsulate these findings, a nonequilibrium phase diagram that visually maps the multiscale characteristics of KHI is constructed. This diagram not only provides intuitive insights into the dynamic interplay of different nonequilibrium effects but also serves as a kinetic roadmap for selecting suitable models under diverse nonequilibrium conditions. Copyright © 2025, The Authors. All rights reserved.

关键词： Phase space methods

Thermodynamic nonequilibrium effects in three-dimensional high-speed compressible flows: Multiscale modeling and simulation via the discrete Boltzmann method

学校读者我要写书评

暂无评论

arXiv 2025年

作者： Guo, Qinghong Gan, Yanbiao Yang, Bin Wu, Yanhong Lai, Huilin Xu, Aiguo Fujian Normal University Fuzhou350117 China Hebei Key Laboratory of Trans-Media Aerial Underwater Vehicle North China Institute of Aerospace Engineering Langfang065000 China School of Energy and Safety Engineering Tianjin Chengjian University Tianjin300384 China National Key Laboratory of Computational Physics Institute of Applied Physics and Computational Mathematics P. O. Box 8009-26 Beijing100088 China National Key Laboratory of Shock Wave and Detonation Physics Mianyang621999 China HEDPS Center for Applied Physics and Technology College of Engineering Peking University Beijing100871 China State Key Laboratory of Explosion Science and Safety Protection Beijing Institute of Technology Beijing100081 China

Three-dimensional (3D) high-speed compressible flow is a typical nonlinear, nonequilibrium, and multiscale complex flow. Traditional fluid mechanics models, based on the quasi-continuum assumption and near-equilibrium approximation, are insufficient to capture significant discrete effects and thermodynamic nonequilibrium effects (TNEs) as the Knudsen number increases. To overcome these limitations, a discrete Boltzmann modeling and simulation method, rooted in kinetic and mean-field theories, has been developed. By applying Chapman-Enskog multiscale analysis, the essential kinetic moment relations Φ = (M0,M1,M20,M2,M31,M3,M42,M4,M53) for characterizing second-order TNEs are determined. These relations Φ are invariants in coarse-grained physical modeling, providing a unique mesoscopic perspective for analyzing TNE behaviors. A discrete Boltzmann model, accurate to the second-order in the Knudsen number, is developed to enable multiscale simulations of 3D supersonic flows. As key TNE measures, nonlinear constitutive relations (NCRs), are theoretically derived for the 3D case, offering a constitutive foundation for improving macroscopic fluid modeling. The NCRs in three dimensions exhibit greater complexity than their two-dimensional counterparts. This complexity arises from increased degrees of freedom, which introduce additional kinds of nonequilibrium driving forces, stronger coupling between these forces, and a significant increase in nonequilibrium components. At the macroscopic level, the model is validated through several classical test cases, ranging from 1D to 3D scenarios, from subsonic to supersonic regimes. At the mesoscopic level, the model accurately captures typical TNEs, such as viscous stress and heat flux, around mesoscale structures, across various scales and orders. This work provides kinetic insights that advance multiscale simulation techniques for 3D high-speed compressible flows. Copyright © 2025, The Authors. All rights reserved.

关键词： Compressible flow

Discrete Lehmann representation of three-point functions

学校读者我要写书评

暂无评论

Physical Review B 2025年第3期111卷 035135-035135页

作者： Dominik Kiese Hugo U. R. Strand Kun Chen Nils Wentzell Olivier Parcollet Jason Kaye Center for Computational Quantum Physics Flatiron Institute 162 5th Avenue New York New York 10010 USA School of Science and Technology Örebro University SE-701 82 Örebro Sweden CAS Key Laboratory of Theoretical Physics Institute of Theoretical Physics Chinese Academy of Sciences Beijing 100190 China Université Paris-Saclay CNRS CEA Institut de Physique Théorique 91191 Gif-sur-Yvette France Center for Computational Mathematics Flatiron Institute 162 5th Avenue New York New York 10010 USA

We present a generalization of the discrete Lehmann representation (DLR) to three-point correlation and vertex functions in imaginary time and Matsubara frequency. The representation takes the form of a linear combination of judiciously chosen exponentials in imaginary time, and products of simple poles in Matsubara frequency, which are universal for a given temperature and energy cutoff. We present a systematic algorithm to generate compact sampling grids, from which the coefficients of such an expansion can be obtained by solving a linear system. We show that the explicit form of the representation can be used to evaluate diagrammatic expressions involving infinite Matsubara sums, such as polarization functions or self-energies, with controllable, high-order accuracy. This collection of techniques establishes a framework through which methods involving three-point objects can be implemented robustly, with a substantially reduced computational cost and memory footprint.

关键词： Natural frequencies

Quantum Delocalization Enables Water Dissociation on Ru(0001)

学校读者我要写书评

暂无评论

Physical Review Letters 2025年第17期134卷 178001-178001页

作者： Yu Cao Jiantao Wang Mingfeng Liu Yan Liu Hui Ma Cesare Franchini Yan Sun Georg Kresse Xing-Qiu Chen Peitao Liu Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences 110016 Shenyang China School of Materials Science and Engineering University of Science and Technology of China 110016 Shenyang China University of Vienna Faculty of Physics and Center for Computational Materials Science Kolingasse 14-16 A-1090 Vienna Austria Dipartimento di Fisica e Astronomia Università di Bologna 40127 Bologna Italy

We revisit the long-standing question of whether water molecules dissociate on the Ru(0001) surface through nanosecond-scale path-integral molecular dynamics simulations on a sizable supercell. This is made possible through the development of an efficient and reliable machine-learning potential with near first-principles accuracy, overcoming the limitations of previous ab initio studies. We show that the quantum delocalization associated with nuclear quantum effects enables rapid and frequent proton transfers between water molecules, thereby facilitating the water dissociation on Ru(0001). This work provides the direct theoretical evidence of water dissociation on Ru(0001), resolving the enduring issue in surface sciences and offering crucial atomistic insights into water-metal interfaces.

关键词： Molecules

Effects of reflection distance on Richtmyer–Meshkov instability in the reshock process: A discrete Boltzmann study

学校读者我要写书评

暂无评论

arXiv 2025年

作者： Lai, Huilin Lin, Chuandong Li, Demei Yang, Tao Gan, Yanbiao Lian, Lingyan Xu, Aiguo Fujian Normal University Fuzhou350117 China Sino-French Institute of Nuclear Engineering and Technology Sun Yat-sen University Zhuhai519082 China Key Laboratory for Thermal Science and Power Engineering of Ministry of Education Department of Energy and Power Engineering Tsinghua University Beijing100084 China Hebei Key Laboratory of Trans-Media Aerial Underwater Vehicle School of Liberal Arts and Sciences North China Institute of Aerospace Engineering Langfang065000 China National Key Laboratory of Computational Physics Institute of Applied Physics and Computational Mathematics P. O. Box 8009-26 Beijing100088 China National Key Laboratory of Shock Wave and Detonation Physics Mianyang621999 China HEDPS Center for Applied Physics and Technology College of Engineering Peking University Beijing100871 China State Key Laboratory of Explosion Science and Safety Protection Beijing Institute of Technology Beijing100081 China

The Richtmyer–Meshkov (RM) instability occurs when a perturbed interface between two fluids undergoes impulsive acceleration due to a shock wave. In this paper, a numerical investigation of the RM instability during the reshock process is conducted using the two-component discrete Boltzmann method. The influence of reflection distance on the RM instability, including both hydrodynamic and thermodynamic non-equilibrium effects, is explored in detail. The interaction time between the reflected shock wave and the material interface varies with different reflection distances. Larger reflection distances lead to a longer evolution time of the material interface before reshock, resulting in more complex effects on the interface deformation, the mixing extent of the fluid system, and non-equilibrium behaviors after reshock. Additionally, while the reflection distance has a minimal impact on mixing entropy before the secondary impact, a significant difference emerges after the secondary impact. This suggests that the secondary impact enhances the evolution of the RM instability. Furthermore, non-equilibrium behaviors or quantities exhibit complex dynamics due to the influence of the transmitted shock wave, transverse waves, rarefaction waves, material interfaces, and dissipation/diffusion processes. Copyright © 2025, The Authors. All rights reserved.

关键词： Shock waves