检索结果-内蒙古大学图书馆

Z-Laminating Assembly of Graphene Nanoflakes for Super-Strong Membranes and Functional Coatings

学校读者我要写书评

暂无评论

ACS Applied Nano Materials 2024年第13期7卷 14957-14963页

作者： Santos, Ian Daniell Tjarks, Patrick Muthu, Jeyavelan Lin, You-Chen Yen, Zhi-Long Chand, Pradyumna Kumar Raman, Radha Nguyen, Dinh Tuan Rouhani, Mehdi Jeng, Yeau-Ren Hsieh, Ya-Ping Hofmann, Mario Department of Physics National Taiwan University Taipei 106 Taiwan Nano Science and Technology Program Taiwan International Graduate Program Academia Sinica and National Taiwan University Taipei 106 Taiwan J. Heyrovsky Institute of Physical Chemistry of the Czech Academy of Sciences Prague 18200 Czech Republic Institute of Atomic and Molecular Sciences Academia Sinica Taipei 106 Taiwan Department of Chemistry National Taiwan University Taipei 106 Taiwan Department of Physics National Central University Taoyuan 320 Taiwan Molecular Science and Technology Program Taiwan International Graduate Program Academia Sinica and National Central University Taipei 106 Taiwan Department of Biomedical Engineering National Cheng Kung University 1 University Road Tainan 70101 Taiwan Department of Materials Science and Engineering National Cheng Kung University Tainan 70101 Taiwan Academy of Innovative Semiconductor and Sustainable Manufacturing National Cheng-Kung University (NCKU) Tainan 70101 Taiwan

We demonstrate the strengthening of graphene, an atomically thin carbon allotrope, by out-of-plane folding. Through lateral confinement of graphene at the water-air interface, nanoscale buckling was induced in suspended flakes, leading to an unexpected folding transition beyond a critical surface pressure. The emergence of folding was confirmed by in situ Brewster angle reflectivity and ex situ microscopy, showing a unique “z-laminated” nanostructure. Molecular dynamics simulations indicate that z-lamination yields an enhanced adhesion between neighboring flakes compared to lateral sliding, which was confirmed by a surface pressure hysteresis during the folding process. Mechanical testing reveals superior Young’s modulus and yield strength when compared to conventional graphene assemblies and even compared to composites. We demonstrate the potential of the z-lamination approach for applications in graphene-based structural materials, tribological layers, and functional electrochemical coatings. Finally, the complete recyclability of z-laminated graphene opens up new routes toward sustainable nanostructured materials. © 2024 The Authors. Published by American Chemical Society

关键词： 2D materials composites laminated graphene membranes recyclable

Enhanced Sampling with Machine Learning: A Review

学校读者我要写书评

暂无评论

arXiv 2023年

作者： Mehdi, Shams Smith, Zachary Herron, Lukas Zou, Ziyue Tiwary, Pratyush Institute for Physical Science and Technology University of Maryland College Park20742 United States Biophysics Program University of Maryland College Park20742 United States Department of Chemistry and Biochemistry University of Maryland College Park20742 United States

Molecular dynamics (MD) enables the study of physical systems with excellent spatiotemporal resolution but suffers from severe time-scale limitations. To address this, enhanced sampling methods have been developed to improve exploration of configurational space. However, implementing these is challenging and requires domain expertise. In recent years, integration of machine learning (ML) techniques in different domains has shown promise, prompting their adoption in enhanced sampling as well. Although ML is often employed in various fields primarily due to its data-driven nature, its integration with enhanced sampling is more natural with many common underlying synergies. This review explores the merging of ML and enhanced MD by presenting different shared viewpoints. It offers a comprehensive overview of this rapidly evolving field, which can be difficult to stay updated on. We highlight successful strategies like dimensionality reduction, reinforcement learning, and flow-based methods. Finally, we discuss open problems at the exciting ML-enhanced MD interface. © 2023, CC BY.

关键词： Molecular dynamics

Clarification of underneath capacity loss for O3-type Ni, co free layered cathodes at high voltage for sodium ion batteries

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2023年第2期77卷 479-486,I0012页

作者： Dong Zhou De Ning Jun Wang Jiahua Liu Gaoyuan Zhang Yinguo Xiao Jiaxin Zheng Yongli Li Jie Li Xinzhi Liu Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices School of PhysicsSun Yat-sen UniversityGuangzhou 510275GuangdongChina School of Innovation and Entrepreneurship Southern University of Science and TechnologyShenzhen 518055GuangdongChina Centre for Photonics Information and Energy Materials Shenzhen Institutes of Advanced TechnologyChinese Academy of SciencesShenzhen 518055GuangdongChina School of Advanced Materials Peking University Shenzhen Graduate SchoolShenzhen 518055GuangdongChina Institute for Clean Energy Technology North China Electric Power UniversityBeijing 102206China Department of Energy Politecnico di MilanoVia Lambruschini 4Milano 20156Italy Centre for Physical Mechanics and Biophysics School of PhysicsSun Yat-sen UniversityGuangzhou 510275GuangdongChina

Earth abundant O3-type NaFe_(0.5)Mn_(0.5)O_(2)layered oxide is regarded as one of the most promising cathodes for sodium ion batteries due to its low cost and high energy ***,its poor structural stability and cycle life strongly impede the practical ***,the dynamic phase evolution as well as charge compensation mechanism of O3-type NaFe_(0.5)Mn_(0.5)O_(2)cathode during sodiation/desodiation are revealed by a systemic study with operando X-ray diffraction and X-ray absorption spectroscopy,high resolution neutron powder diffraction and neutron pair distribution *** layered structure experiences a phase transition of O3→P3→OP2→ramsdellite during the desodiation,and a new O3’phase is observed at the end of the discharge state(1.5 V).The density functional theory(DFT)calculations and nPDF results suggest that depletion of Na^(+)ions induces the movement of Fe into Na layer resulting the formation of an inert ramsdellite phase thus causing the loss of capacity and structural ***,the operando XAS clarified the voltage regions for active Mn^(3+)/Mn^(4+)and Fe^(3+)/Fe^(4+)redox *** work points out the universal underneath problem for Fe-based layered oxide cathodes when cycled at high voltage and highlights the importance to suppress Fe migration regarding the design of high energy O3-type cathodes for sodium ion batteries.

关键词： Sodium ion batteries Layered oxide cathode Iron migration Operando X-ray absorption spectroscopy Neutron measurements

Data Analytics and Visualization in Bimanual Rehabilitation Monitoring Systems: A User-Centered Design Approach to Healthcare Professionals Decision Support

学校读者我要写书评

暂无评论

Data Analytics and Visualization in Bimanual Rehabilitation ...

International Conference on Electrical Engineering and Informatics (ICELTICs)

作者： Parkpoom Wisedsri Chutiporn Anutariya Aekavute Sujarae Roongtiwa Vachalathiti Sunee Bovonsunthonchai Computer Science Program School of Engineering and Technology Asian Institute of Technology Pathum Thani Thailand Punsarn Asia Co. Ltd Thailand Faculty of Physical Therapy Mahidol University Nakhon Pathom (MU) Thailand

ISBN: (数字)9798350366822

ISBN: (纸本)9798350366839

This study presents the design of a user-centered data visualization dashboard for stroke rehabilitation, which integrates the principles of visualization data analytics techniques in the field of healthcare. Addressing the complexities of visualizing for robotic bimanual rehabilitation, the design introduces novel methods to enhance data visualization, broadening monitoring capabilities, and improving the clarity of torque data. These enhancements lead to a clearer understanding of patient robot interactions. A prototype has been developed to visualize transparent torque data from a bimanual master slave robotic system, enabling healthcare professionals to monitor patient progress effectively. The dashboard features intuitive visual representations of master, slave, and assistive torques, simulating elbow joint movements through line and sunburst charts. Feedback from rehabilitation therapists during the design process ensures that the visualization approach is aligned with clinical needs. The findings suggest that the system can assist physiotherapists in devising personalized treatment strategies by providing actionable insights from the recorded data. However, additional research is needed to integrate real clinical data into the system for further enhancement and validation. This innovation has the potential to significantly improve stroke rehabilitation effectiveness and patient outcomes through a bimanual rehabilitation visualization and decision support system.

关键词： Data analysis Torque User centered design Data visualization Prototypes Medical services Stroke (medical condition) Main-secondary Monitoring Robots

From latent dynamics to meaningful representations

学校读者我要写书评

暂无评论

arXiv 2022年

作者： Wang, Dedi Wang, Yihang Evans, Luke Tiwary, Pratyush Biophysics Program Institute for Physical Science and Technology University of Maryland College Park20742 United States Department of Mathematics University of Maryland College ParkMD20742 United States Department of Chemistry and Biochemistry Institute for Physical Science and Technology University of Maryland College Park20742 United States

While representation learning has been central to the rise of machine learning and artificial intelligence, a key problem remains in making the learnt representations meaningful. For this the typical approach is to regularize the learned representation through prior probability distributions. However such priors are usually unavailable or are ad hoc. To deal with this, recent efforts have shifted towards leveraging the insights from physical principles to guide the learning process. In this spirit, we propose a purely dynamics-constrained representation learning framework. Instead of relying on predefined probabilities, we restrict the latent representation to follow overdamped Langevin dynamics with a learnable transition density - a prior driven by statistical mechanics. We show this is a more natural constraint for representation learning in stochastic dynamical systems, with the crucial ability to uniquely identify the ground truth representation. We validate our framework for different systems including a real-world fluorescent DNA movie dataset. We show that our algorithm can uniquely identify orthogonal, isometric and meaningful latent representations. © 2022, CC BY.

关键词： Probability distributions

Cyclodextrin-modified layered double hydroxide thin-film nanocomposite desalination membrane for boron removal

学校读者我要写书评

暂无评论

Cyclodextrin-modified layered double hydroxide thin-film nan...

2023 AIChE Annual Meeting

作者： Ee, Liang Ying Zhao, Qipeng Gao, Jie Lim, Chit Kai Xue, Kai Chin, Sze Yuet Li, Sam Fong Yau Chung, Tai-Shung Chen, Shing Bor Department of Chemical and Biomolecular Engineering College of Design and Engineering National University of Singapore 4 Engineering Drive 4 Singapore117585 Singapore Department of Chemistry College of Humanities and Sciences National University of Singapore 3 Science Drive 3 Singapore117543 Singapore Chemical Engineering Program Physical Science and Engineering Division King Abdullah University of Science and Technology Thuwal23955-6900 Saudi Arabia Centre of High Field NMR Spectroscopy and Imaging School of Physical and Mathematical Sciences College of Science Nanyang Technological University 21 Nanyang Link Singapore637371 Singapore NUS Environmental Research Institute National University of Singapore T-Lab Building 5A Engineering Drive 1 Singapore117411 Singapore Graduate Institute of Applied Science and Technology National Taiwan University of Science and Technology Taipei106335 Taiwan

Directly and instantly seeing through random diffusers by self-imaging in scattering speckles

学校读者我要写书评

暂无评论

PhotoniX 2023年第1期4卷 674-687页

作者： Jietao Liu Wenhong Yang Guofeng Song Qiaoqiang Gan Laboratory of Photonic Integrated Circuits Xiong’an Institute of InnovationChinese Academy of SciencesXiong’an New AreaBeijing 071700Hebei ProvinceChina 2 Sustainability&Photonics Energy Research LaboratoryMaterial Science Engineering programDivision of Physical Science&EngineeringKing Abdullah University of Science and TechnologyThuwalSaudi Arabia

Imaging through scattering medium is challenging but important for different *** advances rely on computational image reconstruction from scattering *** these conventional investigations,speckles were always treated as scrambled grainy *** seeing through scattering diffusers has never been ***,we report a new strategy to see through random diffusers directly using self-imaging of *** analyzing the physics,a direct observation strategy through scattering media is reported with improved image *** this method,we experimentally demonstrated reconstruction-free real-time imaging of static and moving objects with their actual orientation information under single-wavelength and white light *** also proposed a modified speckle autocorrelation imaging(SAI)method inspired by the self-imaging ***,our strategy requires no pre-calibration or acquisition of point-spread-function,no active control of wavefronts or complicated equipment,nor iterations or carefully adjusted parameters,paving the way towards rapid and high-quality imaging through scattering diffusers.

关键词： speckle random instant

Is the Local Ion Density Sufficient to Drive NaCl Nucleation from the Melt and Aqueous Solution?

学校读者我要写书评

暂无评论

arXiv 2023年

作者： Wang, Ruiyu Mehdi, Shams Zou, Ziyue Tiwary, Pratyush Institute for Physical Science and Technology University of Maryland College ParkMD20742 United States Biophysics Program University of Maryland College ParkMD20742 United States Department of Chemistry and Biochemistry University of Maryland College ParkMD20742 United States

Even though nucleation is ubiquitous in different science and engineering problems, investigating nucleation is extremely difficult due to the complicated ranges of time and length scales involved. In this work, we simulate NaCl nucleation in both molten and aqueous environments using enhanced sampling all-atom molecular dynamics with deep learning-based estimation of reaction coordinates. By incorporating various structural order parameters and learning the reaction coordinate as a function thereof, we achieve significantly improved sampling relative to traditional ad hoc descriptions of what drives nucleation, particularly in the aqueous medium. Our results reveal a one-step nucleation mechanism in both environments, with reaction coordinate analysis highlighting the importance of local ion density in distinguishing solid and liquid states. However, while fluctuations in the local ion density are necessary to drive nucleation, they are not sufficient. Our analysis shows that near the transition states, descriptors such as enthalpy and local structure become crucial. Our protocol proposed here enables robust nucleation analysis and phase sampling, and could offer insights into nucleation mechanisms for generic small molecules in different environments. © 2023, CC BY-NC-ND.

关键词： Nucleation

Quantifying the relevance of long-range forces for crystal nucleation in water

学校读者我要写书评

暂无评论

arXiv 2023年

作者： Zhao, Renjie Zou, Ziyue Weeks, John D. Tiwary, Pratyush Chemical Physics Program Institute for Physical Science and Technology University of Maryland College Park20742 United States Department of Chemistry and Biochemistry University of Maryland College Park20742 United States Institute for Physical Science and Technology Department of Chemistry and Biochemistry University of Maryland College Park20742 United States

Understanding nucleation from aqueous solutions is of fundamental importance in a multitude of fields, ranging from materials science to biophysics. The complex solvent-mediated interactions in aqueous solutions hamper the development of a simple physical picture elucidating the roles of different interactions in nucleation processes. In this work we make use of three complementary techniques to disentangle the role played by short and long-range interactions in solvent mediated nucleation. Specifically, the first approach we utilize is the local molecular field (LMF) theory to renormalize long-range Coulomb electrostatics. Secondly, we use well-tempered metadynamics to speed up rare events governed by short-range interactions. Thirdly, deep learning-based State Predictive Information Bottleneck approach is employed in analyzing the reaction coordinate of the nucleation processes obtained from LMF treatment coupled with well-tempered metadynamics. We find that the two-step nucleation mechanism can largely be captured by the short-range interactions, while the long-range interactions further contribute to the stability of the primary crystal state at ambient conditions. Furthermore, by analyzing the reaction coordinate obtained from combined LMF-metadynamics treatment, we discern the fluctuations on different time scales, highlighting the need for long-range interactions when accounting for metastability. Copyright © 2023, The Authors. All rights reserved.

关键词： Nucleation