检索结果-内蒙古大学图书馆

The influence of bottom disturbances on wave generation in a viscous liquid in the presence of uniform current

Ocean Engineering 2024年 304卷

作者： Prasad, I.M. Behera, H. Mandal, B.N. Department of Mathematics SRM Institute of Science and Technology Kattankulathur 603203 Tamil Nadu India Center of Excellence for Ocean Engineering National Taiwan Ocean University Keelung202301 Taiwan Physics and Applied Mathematics Unit Indian Statistical Institute 203 B.T. Road Kolkata700108 India

In the present paper, the effect of bottom disturbances on wave generation in a viscous liquid in the presence of uniform current is studied. The wave potential and Stokes stream function are used to formulate this problem. Multiple integrals representing the free surface elevation are obtained by mathematical analysis using the Laplace transform in time and the Fourier transform in space. This is divided into various multiple integrals, using the steepest descent method to evaluate them asymptotically for a large time and distance. There are three types of ground disturbances taken into consideration: D0(x)=e(−x2/2), D0(x)=e−|x|, and D0(x)=δ(x). The effect of uniform current speed (U) and viscosity (ν) on the free surface elevation is illustrated for the three forms of ground disturbances. It is observed that the presence of current often amplifies the energy of the propagating wave and also increases its amplitude. Moreover, as viscosity increases, the amplitude of free surface elevation decreases with respect to time, and further, the period of oscillation of surface elevation becomes smaller for a large time. © 2024 Elsevier Ltd

关键词： Laplace transforms

来源：评论

学校读者我要写书评

暂无评论

Boosting the oxygen reduction activity on metal surfaces by fine-tuning interfacial water with midinfrared stimulation

引用

The Innovation 2025年第1期6卷 80-86,79页

作者： Qilin Zhang Yu Wu Hao Sun Zhongjie Zhu Hongwei Zhao Jinrong Yang Jie Wang Min Chen Sanzhao Song Shiyou Zheng Dengsong Zhang Hui Yang Zhi Zhu Chunlei Wang School of Mathematics Physics and Finance Anhui Polytechnic UniversityWuhu 241000China Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China School of Materials and Chemistry University of Shanghai for Science and TechnologyShanghai 200093China Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201210China School of Chemistry and Molecular Engineering East China Normal UniversityShanghai 200062China Wenzhou Institute University of Chinese Academy of SciencesWenzhouZhejiang 325001China Innovation Institute of Carbon Neutrality Shanghai UniversityShanghai 200444China College of Medical Instrumentation Shanghai University of Medicine and Health SciencesShanghai 201318China School of Optical-Electrical and Computer Engineering University of Shanghai for Science and TechnologyShanghai 200093China International Joint Laboratory of Catalytic Chemistry College of SciencesShanghai UniversityShanghai 200444China

Heterogeneous catalysis at the metal surface generally involves the transport of molecules through the interfacial water layer to access the surface,which is a rate-determining step at the *** this study,taking the oxygen reduction reaction on a metal electrode in aqueous solution as an example,using accurate molecular dynamic simulations,we propose a novel long-range regulation strategy in which midinfrared stimulation(MIRS)with a frequency of approximately 1,000 cm^(-1)is applied to nonthermally induce the structural transition of interfacial water from an ordered to disordered state,facilitating the access of oxygen molecules to metal surfaces at room temperature and increasing the oxygen reduction activity ***,the theoretical prediction is confirmed by the experimental observation of a significant discharge voltage increase in zinc-air batteries under *** MIRS approach can be seamlessly integrated into existing strategies,offering a new approach for accelerating heterogeneous reactions and gas sensing within the interfacial water system.

关键词： accurate molecular dynamic simulationswe heterogeneous catalysis metal electrode interfacial water metal surface transport molecules interfacial water layer midinfrared stimulation midinfrared stimulation mirs

来源：评论

学校读者我要写书评

暂无评论

LMA Detection Via Circumferential Spatial Information Learning with Hall Sensor Array for Steel Wire Ropes

LMA Detection Via Circumferential Spatial Information Learni...

引用

China Instrument and Control Society (ACCIS), Academic Conference of

作者： Yicheng Huang Zhiliang Liu Leilei Yang Liyuan Ren Glasgow Collage University of Electronic Science and Technology of China Chengdu China School of Mechanical and Electrical Engineering University of Electronic Science and Technology of China Chengdu China Institute of Applied Physics and Computational Mathematics Beijing China

ISBN: (数字)9798350350326

ISBN: (纸本)9798350350333

In the industrial sector, steel wire ropes (SWR) are crucial for traction. Early damage such as wear can lead to further loss of metallic cross-sectional area (LMA) of SWR. In existing studies, LMA-type defects are mainly measured using PCB coils, which sense the overall change of magnetic flux will ignore the information of the circumferential distribution of magnetic flux, resulting in insufficient detection accuracy. To address these issues, this paper utilizes spatial information from Hall sensors and an improved CNN network to extract LMArelated cross-sectional loss characteristics. This approach enhances the utilization of the circumferential information obtained by Hall sensors and achieves excellent quantitative detection results. Experimental validation shows that even under complex conditions, the average error rate for LMA detection is below 0.1%. Therefore, this paper proposes a highaccuracy and noise-resistant LMA detection method based on Hall sensors.

关键词： Coils Magnetic flux Accuracy Statistical analysis Magnetic sensors Noise Sensor phenomena and characterization Wire Steel Sensor arrays

来源：评论

学校读者我要写书评

暂无评论

The challenges of the nonlinear regime for physics-informed neural networks 24

The challenges of the nonlinear regime for physics-informed ...

引用

Proceedings of the 38th International Conference on Neural Information Processing Systems

作者： Andrea Bonfanti Giuseppe Bruno Cristina Cipriani BMW AG Digital Campus Munich Basque Center for Applied Mathematics University of the Basque Country BMW AG Digital Campus Munich Technical University of Munich Munich Center for Machine Learning Munich Data Science Institute

ISBN: (纸本)9798331314385

The Neural Tangent Kernel (NTK) viewpoint is widely employed to analyze the training dynamics of overparameterized physics-Informed Neural Networks (PINNs). However, unlike the case of linear Partial Differential Equations (PDEs), we show how the NTK perspective falls short in the nonlinear scenario. Specifically, we establish that the NTK yields a random matrix at initialization that is not constant during training, contrary to conventional belief. Another significant difference from the linear regime is that, even in the idealistic infinite-width limit, the Hessian does not vanish and hence it cannot be disregarded during training. This motivates the adoption of second-order optimization methods. We explore the convergence guarantees of such methods in both linear and nonlinear cases, addressing challenges such as spectral bias and slow convergence. Every theoretical result is supported by numerical examples with both linear and nonlinear PDEs, and we highlight the benefits of second-order methods in benchmark test cases.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Rigorous justification of the hydrostatic approximation limit of viscous compressible flows

arXiv

引用

arXiv 2023年

作者： Liu, Xin Titi, Edriss S. Department of Mathematics Texas A&M University College StationTX77843 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

This paper considers the asymptotic limit of small aspect ratio between vertical and horizontal spatial scales for viscous isothermal compressible flows. In particular, it is observed that fast vertical acoustic waves arise and induce an averaging mechanism of the density in the vertical variable, which at the limit leads to the hydrostatic approximation of compressible flows, i.e., the compressible primitive equations of atmospheric dynamics. We justify the hydrostatic approximation for general as well as "well-prepared" initial data. The initial data is called well-prepared when it is close to the hydrostatic balance in a strong topology. Moreover, the convergence rate is calculated in the well-prepared initial data case in terms of the aspect ratio, as the latter goes to *** Codes 35B25, 35B40, 76N10, 76N30 © 2023, CC BY-NC-ND.

关键词： Compressible flow

来源：评论

学校读者我要写书评

暂无评论

Specialising neural network potentials for accurate properties and application to the mechanical response of titanium

引用

npj Computational Materials 2021年第1期7卷 1908-1918页

作者： Tongqi Wen Rui Wang Lingyu Zhu Linfeng Zhang Han Wang David J.Srolovitz Zhaoxuan Wu Department of Materials Science and Engineering City University of Hong KongKowloonHong KongSARChina Hong Kong Institute for Advanced Study City University of Hong KongKowloonHong KongSARChina Beijing Institute of Big Data Research BeijingChina Laboratory of Computational Physics Institute of Applied Physics and Computational MathematicsBeijingChina Department of Mechanical Engineering The University of Hong KongHong KongSARChina International Digital Economy Academy(IDEA) ShenzhenChina

Large scale atomistic simulations provide direct access to important materials phenomena not easily accessible to experiments or quantum mechanics-based calculation *** and efficient interatomic potentials are the key enabler,but their development remains a challenge for complex materials and/or complex *** learning potentials,such as the Deep Potential(DP)approach,provide robust means to produce general purpose interatomic ***,we provide a methodology for specialising machine learning potentials for high fidelity simulations of complex phenomena,where general potentials do not *** an example,we specialise a general purpose DP method to describe the mechanical response of two allotropes of titanium(in addition to other defect,thermodynamic and structural properties).The resulting DP correctly captures the structures,energies,elastic constants andγ-lines of Ti in both the HCP and BCC structures,as well as properties such as dislocation core structures,vacancy formation energies,phase transition temperatures,and thermal *** DP thus enables direct atomistic modelling of plastic and fracture behaviour of *** approach to specialising DP interatomic potential,DPspecX,for accurate reproduction of properties of interest“X”,is general and extensible to other systems and properties.

关键词： titanium enable neural

来源：评论

学校读者我要写书评

暂无评论

Fundamental interactions in self-organised critical dynamics on higher order networks

引用

The European Physical Journal B 2024年第6期97卷 1-13页

作者： Tadić, Bosiljka Melnik, Roderick Department of Theoretical Physics Jožef Stefan Institute Ljubljana Slovenia Complexity Science Hub Vienna Austria M3AI Laboratory Department of Mathematics MS2Discovery Interdisciplinary Research Institute Wilfrid Laurier University Waterloo Canada BCAM-Basque Center for Applied Mathematics Bilbao Spain

In functionally complex systems, higher order connectivity is often revealed in the underlying geometry of networked units. Furthermore, such systems often show signatures of self-organised criticality, a specific type of non-equilibrium collective behaviour associated with an attractor of internal dynamics with long-range correlations and scale invariance, which ensures the robust functioning of complex systems, such as the brain. Here, we highlight the intertwining of features of higher order geometry and self-organised critical dynamics as a plausible mechanism for the emergence of new properties on a larger scale, representing the central paradigm of the physical notion of complexity. Considering the time-scale of the structural evolution with the known separation of the time-scale in self-organised criticality, i.e., internal dynamics and external driving, we distinguish three classes of geometries that can shape the self-organised dynamics on them differently. We provide an overview of current trends in the study of collective dynamics phenomena, such as the synchronisation of phase oscillators and discrete spin dynamics with higher order couplings embedded in the faces of simplicial complexes. For a representative example of self-organised critical behaviour induced by higher order structures, we present a more detailed analysis of the dynamics of field-driven spin reversal on the hysteresis loops in simplicial complexes composed of triangles. These numerical results suggest that two fundamental interactions representing the edge-embedded and triangle-embedded couplings must be taken into account in theoretical models to describe the influence of higher order geometry on critical dynamics.

关键词：

来源：评论

学校读者我要写书评

暂无评论

X-Ray Scattering for Soft Matter Research at NSLS-II

引用

Synchrotron Radiation News 2023年第2期36卷 24-30页

作者： Barbour, Andi Cai, Yong Q. Fluerasu, Andrei Freychet, Guillaume Fukuto, Masafumi Gang, Oleg Gann, Eliot Laasch, Ricarda Li, Ruipeng Ocko, Benjamin M. Tsai, Esther H. R. Wąsik, Patryk Wiegart, Lutz Yager, Kevin G. Yang, Lin Zhang, Honghu Zhang, Yugang National Synchrotron Light Source II Brookhaven National Laboratory BNL/NSLS-II Upton NY United States Univ. Grenoble Alpes CEA Grenoble Leti France Center for Functional Nanomaterials Brookhaven National Laboratory Upton NY United States Department of Chemical Engineering and Department of Applied Physics and Applied Mathematics Columbia University New York NY United States Materials Measurement Science Division Material Measurement Laboratory National Institute of Standards and Technology Gaithersburg MD United States

来源：评论

学校读者我要写书评

暂无评论

Near-inflection point inflation and production of dark matter during reheating 25

Near-inflection point inflation and production of dark matte...

引用

25th Workshop What Comes Beyond the Standard Models

作者： Ghoshal, Anish Lambiase, Gaetano Pal, Supratik Paul, Arnab Porey, Shiladitya Institute of Theoretical Physics Faculty of Physics University of Warsaw ul. Pasteura 5 Warsaw02-093 Poland Dipartimento di Fisica"E.R. Caianiello" Universita' di Salerno Sa FiscianoI-84084 Italy Gruppo Collegato di Salerno Sa FiscianoI-84084 Italy Physics and Applied Mathematics Unit Indian Statistical Institute Kolkata700108 India Technology Innovation Hub on Data Science Big Data Analytics and Data Curation Indian Statistical Institute Kolkata700108 India Indian School of Physical Sciences Indian Association for the Cultivation of Science Kolkata700032 India Department of Physics and Astronomy Novosibirsk State University Russia

We study slow roll single field inflationary scenario and the production of non-thermal fermionic dark matter, together with standard model Higgs, during reheating. For the inflationary scenario, we have considered two models of polynomial potential - one is symmetric about the origin and another one is not. We fix the coefficients of the potential from the current Cosmic Microwave Background (CMB) data from Planck/BICEP. Next, we explore the allowed parameter space on the coupling (yχ) with inflaton and mass (mχ) of dark matter (DM) particles (χ) produced during reheating and satisfying CMB and several other cosmological constraints. © 2022 DMFA zaloznistvo. All rights reserved.

关键词： Dark Matter

来源：评论

学校读者我要写书评

暂无评论

Enabling MPI communication within Numba/LLVM JIT-compiled Python code using numba-mpi v1.0

arXiv

引用

arXiv 2024年

作者： Derlatka, Kacper Manna, Maciej Bulenok, Oleksii Zwicker, David Arabas, Sylwester Faculty of Mathematics and Computer Science Jagiellonian University Kraków Poland Max Planck Institute for Dynamics and Self-Organization Göttingen Germany Faculty of Physics and Applied Computer Science AGH Univeristy of Krakow Poland

The numba-mpi package offers access to the Message Passing Interface (MPI) routines from Python code that uses the Numba just-in-time (JIT) compiler. As a result, high-performance and multi-threaded Python code may utilize MPI communication facilities without leaving the JIT-compiled code blocks, which is not possible with the mpi4py package, a higher-level Python interface to MPI. For debugging purposes, numba-mpi retains full functionality of the code even if the JIT compilation is disabled. The numba-mpi API constitutes a thin wrapper around the C API of MPI and is built around Numpy arrays including handling of non-contiguous views over array slices. Project development is hosted at GitHub leveraging the mpi4py/setup-mpi workflow enabling continuous integration tests on Linux (MPICH, OpenMPI & Intel MPI), macOS (MPICH & OpenMPI) and Windows (MS MPI). The paper covers an overview of the package features, architecture and performance. As of v1.0, the following MPI routines are exposed and covered by unit tests: size/rank, [i]send/[i]recv, wait[all|any], test[all|any], allreduce, bcast, barrier, scatter/[all]gather & wtime. The package is implemented in pure Python and depends on numpy, numba and mpi4py (the latter used at initialization and as a source of utility routines only). The performance advantage of using numba-mpi compared to mpi4py is depicted with a simple example, with entirety of the code included in listings discussed in the text. Application of numba-mpi for handling domain decomposition in numerical solvers for partial differential equations is presented using two external packages that depend on numba-mpi: py-pde and PyMPdata-MPI. Copyright © 2024, The Authors. All rights reserved.

关键词： Python

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：