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Science (New York, N.Y.) 2025年第6735期387卷 786-791页

作者： Ruta, Francesco L. Shao, Yinming Acharya, Swagata Mu, Anqi Jo, Na Hyun Ryu, Sae Hee Balatsky, Daria Su, Yifan Pashov, Dimitar Kim, Brian S Y Katsnelson, Mikhail I. Analytis, James G. Rotenberg, Eli Millis, Andrew J. van Schilfgaarde, Mark Basov, D.N. Department of Physics Columbia University New York NY USA Department of Applied Physics and Applied Mathematics Columbia University New York NY USA National Renewable Energy Laboratory Golden CO United States Advanced Light Source E.O. Lawrence Berkeley National Laboratory Berkeley CA United States Department of Physics University of Michigan Ann Arbor MI United States Department of Chemistry University of California Berkeley CA United States Department of Physics University of California Berkeley CA United States Theory and Simulation of Condensed Matter King's College London London United Kingdom Department of Mechanical Engineering Columbia University New York NY USA Institute for Molecules and Materials Radboud University Nijmegen Netherlands CIFAR Quantum Materials Toronto ON Canada Kavli Energy Nanoscience Institute Berkeley CA United States Center for Computational Quantum Physics Flatiron Institute New York NY USA Department of Physics University of Colorado Boulder CO United States

Correlated metals may exhibit unusually high resistivity that increases linearly in temperature, breaking through the Mott-Ioffe-Regel bound, above which coherent quasiparticles are destroyed. The fate of collective charge excitations, or plasmons, in these systems is a subject of debate. Several studies have suggested that plasmons are overdamped, whereas other studies have detected propagating plasmons. In this work, we present direct nano-optical images of low-loss hyperbolic plasmon polaritons (HPPs) in the correlated van der Waals metal MoOCl2. HPPs are plasmon-photon modes that waveguide through extremely anisotropic media and are remarkably long-lived in MoOCl2. Photoemission data presented here reveal a highly anisotropic Fermi surface, reconstructed and made partly incoherent, likely through electronic interactions as explained by many-body theory. HPPs remain long-lived despite this, revealing previously unseen imprints of many-body effects on plasmonic collective modes.

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Effective Force Stabilising Technique for the Immersed Boundary Method

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Communications in Computational physics 2023年第1期33卷 349-366页

作者： Arnab Ghosh Alessandro Gabbana Herman Wijshoff Federico Toschi Department of Applied Physics and Science Education Eindhoven University of TechnologyPO Box 5135600 MB EindhovenThe Netherlands Department of Mechanical Engineering Eindhoven University of TechnologyP.O.Box 5135600 MB EindhovenThe Netherlands Canon Production Printing Netherlands B.V. P.O.Box 1015900 MA VenloThe Netherlands

The immersed boundary method has emerged as an efficient approach for the simulation of finite-sized solid particles in complex fluid ***,one of the well known shortcomings of the method is the limited support for the simulation of light particles,*** with a density lower than that of the surrounding fluid,both in terms of accuracy and numerical *** a broad literature exists,with several authors reporting different approaches for improving the stability of the method,most of these attempts introduce extra complexities and are very costly from a computational point of *** this work,we introduce an effective force stabilizing technique,allowing to extend the stability range of the method by filtering spurious oscillations arising when dealing with light-particles,pushing down the particle-to-fluid density ratio as low as *** thoroughly validate the method comparing with both experimental and numerical data available in literature.

关键词： Immersed boundary method lattice Boltzmann method light particle force stabilization added mass effect

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Detection of Arm Swing Limitations in Simulated Parkinson’s Disease Gait Conditions: A Pilot Study

Detection of Arm Swing Limitations in Simulated Parkinson’s...

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18th International Joint Conference on Biomedical engineering Systems and Technologies, BIOSTEC 2025

作者： Polvorinos-Fernández, Carlos Sigcha, Luis Centeno-Cerrato, María Muñoz-Bellido, Elena Asensio, César López, Juan Manuel De Arcas, Guillermo Pavón, Ignacio Instrumentation and Applied Acoustics Research Group Mechanical Engineering Department ETS Ingenieros Industriales Universidad Politécnica de Madrid Madrid Spain Group University of Limerick Limerick Ireland Instrumentation and Applied Acoustics Research Group Department of Audiovisual Engineering and Communications ETS. de Ingeniería y Sistemas de Telecomunicación Universidad Politécnica de Madrid Madrid Spain Instrumentation and Applied Acoustics Research Group Department of Physical Electronics Electrical Engineering and Applied Physics ETS. de Ingeniería y Sistemas de Telecomunicación Universidad Politécnica de Madrid Madrid Spain

Human gait is a biomechanical process vital to health, with abnormalities often linked to neurological disorders like Parkinson's disease (PD). In PD patients, arm swing during walking becomes asymmetric and reduced in amplitude, providing a potential biomarker for early diagnosis and monitoring disease progression. This pilot study focuses on detecting variations in arm swing amplitude and asymmetry using data collected from smartwatches worn by 24 participants under different gait conditions. Participants walked while carrying progressively heavier loads (0 kg, 2 kg, and 4 kg) to simulate restricted arm swing. Machine learning models were developed to classify these conditions using accelerometer and gyroscope data. Results showed that the K-Nearest Neighbours algorithm performed best, achieving up to 94.3% accuracy. Although the models effectively distinguished between load and no-load conditions, it was difficult to differentiate between different load levels. These findings highlight the potential of wearable devices for PD gait analysis, though further refinement and testing with PD patients are needed for clinical application. © 2025 by SCITEPRESS – Science and Technology Publications, Lda.

关键词： Accelerometers

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From Controlled to Free-Living Contexts: Expanding the Monitoring of Motor Symptoms in Parkinson’s Disease with Wearable mHealth Technologies

From Controlled to Free-Living Contexts: Expanding the Monit...

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18th International Joint Conference on Biomedical engineering Systems and Technologies, BIOSTEC 2025

作者： Centeno-Cerrato, María Polvorinos-Fernández, Carlos Sigcha, Luis de Arcas, Guillermo Asensio, César Manuel López, Juan Pavón, Ignacio Instrumentation and Applied Acoustics Research Group Mechanical Engineering Department ETS Ingenieros Industriales Universidad Politécnica de Madrid Madrid Spain Group University of Limerick Limerick Ireland Instrumentation and Applied Acoustics Research Group Department of Audiovisual Engineering and Communications ETS. de Ingeniería y Sistemas de Telecomunicación Universidad Politécnica de Madrid Madrid Spain Instrumentation and Applied Acoustics Research Group Department of Physical Electronics Electrical Engineering and Applied Physics ETS. de Ingeniería y Sistemas de Telecomunicación Universidad Politécnica de Madrid Madrid Spain

This study examines the application of wearable mobile health (mHealth) technologies, specifically smartwatches equipped with inertial sensors, for the monitoring of Parkinson’s disease (PD). The aim is to investigate how the integration of the Monipar tool, designed to monitor supervised exercises, with the BioCliTe system, which continuously collects data during free-living activities, can improve the assessment of motor fluctuations and disease progression. The study proposes a set of free-living activities which can serve as characteristic indicators for assessing motor symptoms. By combining structured exercises with everyday tasks, this approach provides a more comprehensive evaluation of PD, capturing motor symptoms in both controlled and real-world environments. The research seeks to advance disease monitoring and patient care through more accurate tracking and the development of personalized treatment strategies. © 2025 by SCITEPRESS – Science and Technology Publications, Lda.

关键词： Neurodegenerative diseases

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Nullspace Adaptive Model-Based Trajectory-Tracking Control for a 6-DOF Underwater Vehicle with Unknown Plant and Actuator Parameters: Theory and Preliminary Simulation Evaluation

Nullspace Adaptive Model-Based Trajectory-Tracking Control f...

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IEEE International Conference on Robotics and Automation (ICRA)

作者： Annie M. Mao Joseph L. Moore Louis L. Whitcomb Department of Mechanical Engineering Johns Hopkins University Baltimore MD USA Johns Hopkins University Applied Physics Laboratory Laurel MD USA

ISBN: (数字)9798350384574

ISBN: (纸本)9798350384581

We report a novel model-based nullspace adaptive trajectory-tracking control (NS-ATTC) algorithm for fully-actuated 6-degree-of-freedom (DOF) underwater vehicles which estimates unknown plant and actuator model parameters simultaneously. We provide a stability and convergence analysis with proof of asymptotically stable tracking error convergence, as well as a preliminary simulation study demonstrating 6-DOF trajectory tracking. The NS-ATTC algorithm does not require acceleration instrumentation and provides a stable online parameter estimate, enabling robust model-based autonomy.

关键词： Adaptation models Actuators Parameter estimation Trajectory tracking Instruments 6-DOF Stability analysis

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Investigation of wind energy speed and power, and its impact of sustainability: Saudi Arabia a model

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Journal of Umm Al-Qura University for engineering and Architecture 2023年第2期14卷 142-149页

作者： Waheeb, S.A. Al-Samarai, Riyadh A. Alias, M.F.A. Al-Douri, Y. Applied College Umm Al-Qura University PO Box 715 Makkah 21955 Saudi Arabia Electromechanical Engineering Department Engineering College University of Samarra Samarra 34010 Iraq Physics Department College of Science University of Baghdad P.O. Box 47162 Baghdad Iraq Nanotechnology and Catalysis Research Centre University of Malaya Kuala Lumpur 50603 Malaysia Department of Applied Physics and Astronomy College of Sciences University of Sharjah P.O. Box 27272 Sharjah United Arab Emirates Department of Mechanical Engineering Faculty of Engineering Piri Reis University Eflatun Sk. No:8 Tuzla Istanbul 34940 Türkiye

The study of wind energy is presented in six sites;Sharurah, Jeddah South, Al Wajh, Riyadh, Hafar Al Batin and Al Jouf of Saudi Arabia (KSA) is updated. The wind energy and its status are interpreted. The annual mean values of long-term for wind speeds are varied between the years 2000 and 2020. Also, the wind power density annual values are varied between the years 2006 and 2020. In addition, the speed of winds over whole the geography of KSA is researched. The distribution of percent frequency at different speeds of wind of these six sites at 12 m along two decades ago is presented that could affect on sustainability. © The Author(s) 2023.

关键词： Speed Temperature Wind

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Phase field modeling for the morphological and microstructural evolution of metallic materials under environmental attack

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npj Computational Materials 2021年第1期7卷 1299-1319页

作者： Talha Qasim Ansari Haitao Huang San-Qiang Shi Department of Applied Physics and Research Institute of Smart Energy the Hong Kong Polytechnic UniversityHung HomKowloonHong Kong SAR Department of Mechanical Engineering the Hong Kong Polytechnic UniversityHung HomKowloonHong Kong SAR

The complex degradation of metallic materials in aggressive environments can result in morphological and microstructural *** phase-field(PF)method is an effective computational approach to understanding and predicting the morphology,phase change and/or transformation of *** models are based on conserved and non-conserved field variables that represent each phase as a function of space and time coupled with time-dependent equations that describe the *** report summarizes progress in the PF modeling of degradation of metallic materials in aqueous corrosion,hydrogen-assisted cracking,high-temperature metal oxidation in the gas phase and porous structure evolution with insights to future applications.

关键词： corrosion cracking metallic

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Revealing Actual Viscoelastic Relaxation Times in Capillary Breakup

arXiv

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arXiv 2025年

作者： Hu, Nan Hwang, Jonghyun Ruangkriengsin, Tachin Stone, Howard A. Department of Mechanical and Aerospace Engineering Princeton University NJ08544 United States Program in Applied and Computational Mathematics Princeton University NJ08544 United States

We use experiments and theory to elucidate the size effect in capillary breakup rheometry, where pre-stretching in the visco-capillary stage causes the apparent relaxation time to be consistently smaller than the actual value. We propose a method accounting for both the experimental size and the finite extensibility of polymers to extract the actual relaxation time. A phase diagram characterizes the expected measurement variability and delineates scaling law conditions. The results refine capillary breakup rheometry for viscoelastic fluids and advance the understanding of breakup dynamics across scales. Copyright © 2025, The Authors. All rights reserved.

关键词： Relaxation time

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Adaptive Identification of Second-Order mechanical Systems with Nullspace Parameter Structure: Stability and Parameter Convergence

Adaptive Identification of Second-Order Mechanical Systems w...

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IEEE Conference on Decision and Control

ISBN: (数字)9798350316339

ISBN: (纸本)9798350316346

The relationships between persistence of excitation (PE) conditions and asymptotically stable convergence of parameter estimates are well-known for adaptive systems where stability and convergence are derived with respect to the origin of a combined state error and parameter estimation error system. We address a class of second-order mechanical systems in which the true parameters are, rather than one single point in parameter space, members of a nullspace defined by feasible evolutions of a regressor matrix. Differences within the set of true parameters are unobservable, requiring a new characterization of PE and parameter convergence. We report an adaptive identification (AID) approach for this class of systems and show local stability and parameter estimate convergence to the true parameter set under a subspace PE condition. This approach is applicable to many second-order mechanical systems, including robot arms and undersea, land, aerial, and space vehicles, and enables a more complete parameterization of uncertainty in the dynamics, e.g. enabling simultaneous AID of plant and actuator parameters for mechanical systems.

关键词： Space vehicles Asymptotic stability Adaptive systems Uncertainty Parameter estimation Manipulators Stability analysis mechanical systems Vehicle dynamics Convergence

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Multifunctional silicene/CeO_(2)heterojunctions:Desirable electronic material and promising water-splitting photocatalyst

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Chinese Chemical Letters 2022年第8期33卷 3947-3950页

作者： Liang Xu Jian Zeng Quan Li Xin Luo Tong Chen Jingjing Liu Ling-Ling Wang Energy Materials Computing Center School of Energy and Mechanical EngineeringJiangxi University of Science and TechnologyNanchang 330013China Department of Applied Physics School of ScienceEast China Jiaotong UniversityNanchang 330013China Key Laboratory for Micro-Nano Optoelectronic Devices of Ministry of Education School of Physics and ElectronicsHunan UniversityChangsha 410082China

The first-principles calculations demonstrate that covalently bonded(cb)heterojunction and van der Waals(vd W)heterojunction can coexist in silicene/CeO_(2) heterojunctions,due to the different stacking ***,the cb heterojunction with band gap of 1.97 e V,forms a type-II heterojunction,exhibits good redox performance and has high-effective optical absorption spectra,thus it is a promising photocatalyst for overall water ***,for the vd W heterojunction,the Dirac cone of silicene is well kept on CeO_(2) semiconducting substrate,with a considerable energy gap of 0.43 e V,which can be an ideal material in building silicene-based electronic *** results may open a new gateway in both of nanoelectronic device and energy conversion for silicene/Ce O2 nanocomposites.

关键词： Silicene CeO_(2) Photocatalyst Interfacial interaction Dirac cone

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