检索结果-内蒙古大学图书馆

Revealing the Dominance of the Dissolution-Deposition Mechanism in Aqueous Zn−MnO2Batteries

Angewandte Chemie 2023年第6期136卷

作者： Yadong Li Yuhao Li Qingshan Liu Yongshuai Liu Tiansheng Wang Mingjin Cui Prof. Yu Ding Prof. Hongsen Li Prof. Guihua Yu College of Physics Qingdao University Qingdao 266071 China Center of Energy Storage Materials & Technology College of Engineering and Applied Sciences Jiangsu Key Laboratory of Artificial Functional Materials National Laboratory of Solid State Microstructures and Collaborative Innovation Center of Advanced Microstructures Nanjing University Nanjing 210093 P. R. China Materials Science and Engineering Program and Walker Department of Mechanical Engineering The University of Texas at Austin Austin TX 78712 USA

Zn−MnO 2 batteries have attracted extensive attention for grid-scale energy storage applications, however, the energy storage chemistry of MnO 2 in mild acidic aqueous electrolytes remains elusive and controversial. Using α-MnO 2 as a case study, we developed a methodology by coupling conventional coin batteries with customized beaker batteries to pinpoint the operating mechanism of Zn−MnO 2 batteries. This approach visually simulates the operating state of batteries in different scenarios and allows for a comprehensive study of the operating mechanism of aqueous Zn−MnO 2 batteries under mild acidic conditions. It is validated that the electrochemical performance can be modulated by controlling the addition of Mn 2+ to the electrolyte. The method is utilized to systematically eliminate the possibility of Zn 2+ and/or H + intercalation/de-intercalation reactions, thereby confirming the dominance of the MnO 2 /Mn 2+ dissolution-deposition mechanism. By combining a series of phase and spectroscopic characterizations, the compositional, morphological and structural evolution of electrodes and electrolytes during battery cycling is probed, elucidating the intrinsic battery chemistry of MnO 2 in mild acid electrolytes. Such a methodology developed can be extended to other energy storage systems, providing a universal approach to accurately identify the reaction mechanism of aqueous aluminum-ion batteries as well.

关键词： Aqueous Batteries Dissolution-Deposition Mechanism Energy Storage Mechanism Zinc-Ion Batteries

来源：评论

学校读者我要写书评

暂无评论

A Nodal Immersed Finite Element-Finite Difference Method

SSRN

引用

SSRN 2022年

作者： Wells, David Vadala-Roth, Ben Lee, Jae Ho Griffith, Boyce E. Department of Mathematics University of North Carolina Chapel HillNC United States U.S. Army Corps of Engineers Engineer Research and Development Center Coastal and Hydraulic Laboratory VicksburgMS United States Department of Mechanical Engineering Institute for Computational Medicine Johns Hopkins University BaltimoreMD United States Departments of Mathematics Applied Physical Sciences and Biomedical Engineering University of North Carolina Chapel HillNC United States Carolina Center for Interdisciplinary Applied Mathematics University of North Carolina Chapel HillNC United States Computational Medicine Program University of North Carolina Chapel HillNC United States McAllister Heart Institute University of North Carolina Chapel HillNC United States

The immersed finite element-finite difference (IFED) method is a computational approach to modeling interactions between a fluid and an immersed structure. The IFED method uses a finite element (FE) method to approximate the stresses and forces on a structural mesh and a finite difference (FD) method to approximate the momentum of the entire fluid-structure system on a Cartesian grid. The fundamental approach used by this method follows the immersed boundary framework for modeling fluid-structure interaction (FSI), in which a force spreading operator prolongs structural forces to a Cartesian grid, and a velocity interpolation operator restricts a velocity field defined on that grid back onto the structural mesh. With an FE structural mechanics framework, force spreading first requires that the force itself be projected onto the finite element space. Similarly, velocity interpolation requires projecting velocity data onto the FE basis functions. Consequently, evaluating either coupling operator requires solving a matrix equation at every time step. Mass lumping, in which the projection matrices are replaced by diagonal approximations, has the potential to accelerate this method considerably. This paper provides both numerical and computational analyses of the effects of this replacement for evaluating the force projection and for the IFED coupling operators. Constructing the coupling operators also requires determining the locations on the structure mesh where the forces and velocities are sampled. Here we show that sampling the forces and velocities at the nodes of the structural mesh is equivalent to using lumped mass matrices in the IFED coupling operators. A key theoretical result of our analysis is that if both of these approaches are used together, the IFED method permits the use of lumped mass matrices derived from nodal quadrature rules for any standard interpolatory element. This is different from standard FE methods, which require specialized treatments to

关键词： Fluid structure interaction

来源：评论

学校读者我要写书评

暂无评论

The Relationship between Strategic Agility and Resource Base View of the Firm Performance in Manufacturing Industry: The Research Framework

引用

Journal of Physics: Conference Series 2021年第1期1764卷

作者： R Nurjaman A Rahayu L A Wibowo Widjajani Mujiarto Program Studi Teknik Industri Universitas Langlangbuana Program Studi Manajemen Universitas Pendidikan Indonesia Department of Mechanical Engineering Universitas Muhammadiyah Tasikmalaya Indonesia

Competition in various companies encourages practitioners, entrepreneurs and academics to examine the dynamic of business strategy. The spirited study of this business strategy was driven by its forceful environment. Dynamic moving environments require each company to be adaptive as quickly as possible. This adaptation encourages the company to have a certain advantage in facing competition. The winners of the market make the company can demonstrate a fast, flexible response, effective coordination and understanding of internal and external competencies. Similarly, in the manufacturing industry, the dynamic lifestyle of consumers encourages the company to adapt to creating its own excellence. The purpose of this article propose a research framework of the relationship between strategic agility and resource base view to the firm performance of manufacturing industry.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Bayesian Learning-Based Adaptive Control for Safety Critical Systems

Bayesian Learning-Based Adaptive Control for Safety Critical...

引用

IEEE International Conference on robotics and Automation (ICRA)

作者： David D. Fan Jennifer Nguyen Rohan Thakker Nikhilesh Alatur Ali-akbar Agha-mohammadi Evangelos A. Theodorou Institute for Robotics and Intelligent Machines Georgia Institute of Technology Atlanta GA USA Department of Mechanical and Aerospace Engineering West Virginia University Morgantown WV USA NASA Jet Propulsion Laboratory California Institute of Technology Pasadena CA USA

ISBN: (数字)9781728173955

ISBN: (纸本)9781728173962

Deep learning has enjoyed much recent success, and applying state-of-the-art model learning methods to controls is an exciting prospect. However, there is a strong reluctance to use these methods on safety-critical systems, which have constraints on safety, stability, and real-time performance. We propose a framework which satisfies these constraints while allowing the use of deep neural networks for learning model uncertainties. Central to our method is the use of Bayesian model learning, which provides an avenue for maintaining appropriate degrees of caution in the face of the unknown. In the proposed approach, we develop an adaptive control framework leveraging the theory of stochastic CLFs (Control Lyapunov Functions) and stochastic CBFs (Control Barrier Functions) along with tractable Bayesian model learning via Gaussian Processes or Bayesian neural networks. Under reasonable assumptions, we guarantee stability and safety while adapting to unknown dynamics with probability 1. We demonstrate this architecture for high-speed terrestrial mobility targeting potential applications in safety-critical high-speed Mars rover missions.

关键词： Safety Adaptation models Bayes methods Stochastic processes Uncertainty Computational modeling Switches

来源：评论

学校读者我要写书评

暂无评论

Magic-angle bilayer phononic graphene

引用

Physical Review B 2020年第18期102卷 180304(R)-180304(R)页

作者： Yuanchen Deng Mourad Oudich Nikhil JRK Gerard Jun Ji Minghui Lu Yun Jing Graduate Program in Acoustics Penn State University University Park Pennsylvania 16802 USA Université de Lorraine CNRS Institut Jean Lamour F-54000 Nancy France Department of Mechanical and Aerospace Engineering North Carolina State University Raleigh North Carolina 27695 USA National Laboratory of Solid State Microstructures and Department of Materials Science and Engineering Nanjing University Nanjing Jiangsu 210093 China

Thanks to the recent discovery of the magic-angle bilayer graphene, twistronics is quickly becoming a burgeoning field in condensed matter physics. This Rapid Communication expands the realm of twistronics to acoustics by introducing twisted bilayer phononic graphene, which remarkably also harbors the magic angle, evidenced by the associated ultraflat bands. Beyond mimicking quantum-mechanical behaviors of twisted bilayer graphene, we show that their acoustic counterpart offers a considerably more straightforward and robust way to alter the interlayer hopping strength, enabling us to unlock magic angles (>3∘) inaccessible in classical twisted bilayer graphene. This study not only establishes the acoustical analog of twisted (magic-angle) bilayer graphene, providing a test bed more easily accessible to probe the interaction and misalignment between stacked two-dimensional materials, but also points out the direction to a new phononic crystal design paradigm that could benefit applications such as enhanced acoustic emission and sensing.

关键词： Acoustic wave phenomena mechanical & acoustical properties Phonons Acoustic metamaterials Metamaterials

来源：评论

学校读者我要写书评

暂无评论

Editorial

引用

Applied Mechanics Reviews 2018年第1期70卷 050201页

作者： Dankowicz, Harry Kumar, Vijay Krovi, Venkat ASME Applied Mechanics Reviews Department of Mechanical Science and Engineering University of Illinois at Urbana-Champaign UrbanaIL61801 United States Transactions of the ASME Journal of Mechanisms and Robotics Department of Mechanical Engineering and Applied Mechanics University of Pennsylvania PhiladelphiaPA19104 United States Transactions of the ASME Journal of Mechanisms and Robotics Department of Automotive Engineering Clemson University GreenvilleSC29607 United States

Applied Mechanics Reviews (AMR) is an international review journal that serves as a premier venue for state-of-the-art and retrospective survey articles and reviews of research areas and curricular developments across all subdisciplines of applied mechanics and engineering science, including fluid and solid mechanics, heat transfer, dynamics and vibration, and applications. AMR also provides a forum for dissemination of original tutorial articles. These organize novel insight and reflection on the use of one or several methods of modeling, design, analysis, or synthesis in an accessible format that can be used for guided instruction or self-study. The Midwest Mechanics Seminar (MMS) Series brings distinguished scholars from across the broad subdisciplines of mechanics to ten institutions within the Midwest of the United States during two, one-week tours. Speakers give a research seminar at each host institution (Tour A: University of Michigan, Michigan State University, University of Notre Dame,...

关键词： Reflection engineering mechanics Fluids Design Modeling Fluid mechanics engineering teachers

来源：评论

学校读者我要写书评

暂无评论

A modified step characteristic method for solving the SN transport equation

A modified step characteristic method for solving the SN tra...

引用

2019 Transactions of the American Nuclear Society, ANS 2019

作者： Wang, Dean Wu, Zeyun Nuclear Engineering Program Ohio State University 201 W 19th Avenue ColumbusOH43210 United States Department of Mechanical and Nuclear Engineering Virginia Commonwealth University 401 West Main Street RichmondVA23284 United States

来源：评论

学校读者我要写书评

暂无评论

Homography-Based Deep Visual Servoing Methods for Planar Grasps

Homography-Based Deep Visual Servoing Methods for Planar Gra...

引用

2019 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS)

作者： Austin S. Wang Wuming Zhang Daniel Troniak Jacky Liang Oliver Kroemer Department of Mechanical Engineering Carnegie Mellon University Pittsburgh PA USA Robotics Institute Carnegie Mellon University Pittsburgh PA USA National Robotics Engineering Center Pittsburgh PA USA

We propose a visual servoing framework for learning to improve grasps of objects. RGB and depth images from grasp attempts are collected using an automated data collection process. The data is then used to train a Grasp Quality Network (GQN) that predicts the outcome of grasps from visual information. A grasp optimization pipeline uses homography models with the trained network to optimize the grasp success rate. We evaluate and compare several algorithms for adjusting the current gripper pose based on the current observation from a gripper-mounted camera to perform visual servoing. Evaluations in both simulated and hardware environments show considerable improvement in grasp robustness with models trained using less than 30K grasp trials. Success rates for grasping novel objects unseen during training increased from 18.5% to 81.0% in simulation, and from 17.8% to 78.0% in the real world.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Development of a Learning-Based Intention Detection Framework for Power-Assisted Manual Wheelchair Users

Development of a Learning-Based Intention Detection Framewor...

引用

IEEE International Workshop on Robot and Human Communication (ROMAN)

作者： Mahsa Khalili Yang Zhang Alexandra Gil Leo Zhao Calvin Kuo H. F. Machiel Van der Loos Jaimie F. Borisoff School of Biomedical Engineering the University of British Columbia Vancouver BC Canada Department of Mechanical Engineering the University of British Columbia Vancouver BC Canada Mathematics Department the University of British Columbia Vancouver BC Canada Engineering Physics Program the University of British Columbia Vancouver BC Canada International Collaboration on Repair Discoveries (ICORD) British Columbia Institute of Technology (BCIT)

ISBN: (数字)9781728160757

ISBN: (纸本)9781728160764

Pushrim-activated power-assisted wheels (PAPAWs) are assistive technologies that provide on-demand assistance to wheelchair users. PAPAWs operate based on a collaborative control scheme. Therefore, they rely on accurate interpretation of the user's intent to provide effective propulsion assistance. This paper presents a learning-based approach to predict wheelchair users' intention when performing a variety of wheelchair activities. We obtained kinematic and kinetic data from manual wheelchair users when performing standard wheelchair activities such as turns and ascents. Our measurements revealed variability in physical capabilities and propulsion habits of different users, therefore, highlighting the need for the development of personalized intention inference models. We used Gaussian Mixture models to label different phases of user-pushrim interactions based on individual user's wheeling behaviour. Supervised classifiers were trained with each user's data and these models were used to predict the user's intentions during different propulsion activities. We found random forest classifiers had high accuracy (>92%) in predicting different states of individual-specific wheelchair propulsion and user intent for 2 participants. This proposed framework is computationally efficient and can be used for real-time prediction of wheelchair users' intention. The outcome of this clustering-classification pipeline provides relevant information for designing user-specific and adaptive PAPAW controllers.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Towards efficient human-robot collaboration with robust plan recognition and trajectory prediction

arXiv

引用

arXiv 2019年

作者： Cheng, Yujiao Sun, Liting Liu, Changliu Tomizuka, Masayoshi School of Engineering Mechanical Engineering Department University of California Berkeley United States Robotics Institute Carnegie Mellon University Pittsburgh United States

Human-robot collaboration (HRC) is becoming increasingly important as the paradigm of manufacturing is shifting from mass production to mass customization. The introduction of HRC can significantly improve the flexibility and intelligence of automation. To efficiently finish tasks in HRC systems, the robots need to not only predict the future movements of human, but also more high-level plans, i.e., the sequence of actions to finish the tasks. However, due to the stochastic and time-varying nature of human collaborators, it is quite challenging for the robot to efficiently and accurately identify such task plans and respond in a safe manner. To address this challenge, we propose an integrated human-robot collaboration framework. Both plan recognition and trajectory prediction modules are included for the generation of safe and efficient robotic motions. Such a framework enables the robots to perceive, predict and adapt their actions to the human's work plan and intelligently avoid collisions with the human. Moreover, by explicitly leveraging the hierarchical relationship between plans and trajectories, more robust plan recognition performance can be achieved. Physical experiments were conducted on an industrial robot to verify the proposed framework. The results show that the proposed framework could accurately recognize the human workers' plans and thus significantly improve the time efficiency of the HRC team even in the presence of motion classification noises. Copyright © 2019, The Authors. All rights reserved.

关键词： Industrial robots

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：