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Controlling the dynamic behavior of decentralized cluster through centralized approaches

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Chinese physics B 2024年第6期33卷 46-54页

作者：袁大明王培龙王鹏马星宇汪楚云王璟陈怀城王高叶方富 School of Ophthalmology and Optometry Eye HospitalSchool of Biomedical EngineeringWenzhou Medical UniversityWenzhou 325035China Postgraduate Training Base alliance Wenzhou Medical UniversityWenzhou 325035China Wenzhou Institute University of Chinese Academy of SciencesWenzhou 325011China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China

How to control the dynamic behavior of large-scale artificial active matter is a critical concern in experimental research on soft matter, particularly regarding the emergence of collective behaviors and the formation of group patterns. Centralized systems excel in precise control over individual behavior within a group, ensuring high accuracy and controllability in task execution. Nevertheless, their sensitivity to group size may limit their adaptability to diverse tasks. In contrast, decentralized systems empower individuals with autonomous decision-making, enhancing adaptability and system robustness. Yet, this flexibility comes at the cost of reduced accuracy and efficiency in task execution. In this work, we present a unique method for regulating the centralized dynamic behavior of self-organizing clusters based on environmental interactions. Within this environment-coupled robot system, each robot possesses similar dynamic characteristics, and their internal programs are entirely identical. However, their behaviors can be guided by the centralized control of the environment, facilitating the accomplishment of diverse cluster tasks. This approach aims to balance the accuracy and flexibility of centralized control with the robustness and task adaptability of decentralized control. The proactive regulation of dynamic behavioral characteristics in active matter groups, demonstrated in this work through environmental interactions, holds the potential to introduce a novel technological approach and provide experimental references for studying the dynamic behavior control of large-scale artificial active matter systems.

关键词： self-organizing system centralized control dynamics regulation

Characterization and quantification of multi-field coupling in lithium-ion batteries under mechanical constraints

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Journal of Energy Chemistry 2024年第8期95卷 364-379页

作者： Xue Cai Caiping Zhang Zeping Chen Linjing Zhang Dirk Uwe Sauer Weihan Li National Active Distribution Network Technology Research Center Beijing Jiaotong University Chair for Electrochemical Energy Conversion and Storage Systems Institute for Power Electronics and Electrical Drives(ISEA) RWTH Aachen University Center for Ageing Reliability and Lifetime Prediction of Electrochemical and Power Electronic Systems(CARL) Juelich Aachen Research alliance JARA-Energy Helmholtz Institute Münster(HI MS)

The safety and durability of lithium-ion batteries under mechanical constraints depend significantly on electrochemical, thermal, and mechanical fields in applications. Characterizing and quantifying the multi-field coupling behaviors requires interdisciplinary efforts. Here, we design experiments under mechanical constraints and introduce an in-situ analytical framework to clarify the complex interaction mechanisms and coupling degrees among multi-physics fields. The proposed analytical framework integrates the parameterization of equivalent models, in-situ mechanical analysis, and quantitative assessment of coupling behavior. The results indicate that the significant impact of pressure on impedance at low temperatures results from the diffusion-controlled step, enhancing kinetics when external pressure, like 180 to 240 k Pa at 10 °C, is applied. The diversity in control steps for the electrochemical reaction accounts for the varying impact of pressure on battery performance across different temperatures. The thermal expansion rate suggests that the swelling force varies by less than 1.60% per unit of elevated temperature during the lithiation process. By introducing a composite metric, we quantify the coupling correlation and intensity between characteristic parameters and physical fields, uncovering the highest coupling degree in electrochemical-thermal fields. These results underscore the potential of analytical approaches in revealing the mechanisms of interaction among multi-fields, with the goal of enhancing battery performance and advancing battery management.

关键词： Lithium-ion battery Muti-field coupling Mechanical constraints Interaction mechanisms Quantitative analysis

Effect of annealing on structural and optical properties of lead tungstate microcrystals

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Chinese physics B 2011年第11期20卷 397-403页

作者：庞华锋李志杰向霞章春来傅永庆祖小涛 Department of Applied physics University of Electronic Science and Technology of China International Center for Material physics Chinese Academy of Sciences Thin Film Centre Scottish Union of Physics AllianceUniversity of the West of Scotland

Shuttle-like lead tungstate （PbWOa） microcrystals are synthesized at room temperature using the precipitation method with the cetyltrimethyl ammonium bromide. Results from both the X-ray diffraction and the scanning electron microscopy show that the lattice distortions of the PbWO4 microcrystals are reduced significantly when the annealing temperature is increased to 873 K. The result from the ultraviolet-visible diffuse reflectance spectroscopy shows that the exciton absorption appears in the sample annealed at 673 K. The self-trapped exciton luminescence due to the Jahn- Teller effect is also observed in the blue band. The interstitial oxygen ions in the WO42- groups are mainly resposible for the enhancement effect of the green luminescence of the annealed samples. The above results are supported by the spectrum analysis of the as-grown and the post-annealed samples using the X-ray photoelectron spectroscopy.

关键词： PbWO4 microcrystal annealing defects photoluminescence

Two-stage acceleration of interstellar ions driven by high-energy lepton plasma flows

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Science China(physics,Mechanics & Astronomy) 2015年第10期58卷 76-80页

作者： CUI YunQian SHENG ZhengMing LU QuanMing LI YuTong ZHANG Jie Beijing National Laboratory of Condensed Matter physics Institute of Physics Chinese Academy of Sciences scottish universities physics alliance Department of Physics University of Strathclyde Key Laboratory for Laser Plasmas (Mo E) and Department of physics and Astronomy Shanghai Jiao Tong University IFSA Collaborative Innovation Center Shanghai Jiao Tong University School of Earth and Space Sciences University of Science and Technology of China

We present the particle-in-cell(PIC) simulation results of the interaction of a high-energy lepton plasma flow with background electron-proton plasma and focus on the acceleration processes of the protons. It is found that the acceleration follows a two-stage process. In the first stage, protons are significantly accelerated transversely(perpendicular to the lepton flow) by the turbulent magnetic field "islands" generated via the strong Weibel-type instabilities. The accelerated protons shows a perfect inverse-power energy spectrum. As the interaction continues, a shockwave structure forms and the protons in front of the shockwave are reflected at twice of the shock speed, resulting in a quasi-monoenergetic peak located near 200 Me V under the simulation parameters. The presented scenario of ion acceleration may be relevant to cosmic-ray generation in some astrophysical environments.

关键词：等离子体流轻子高能流驱动星际相互作用颗粒细胞不稳定性

Magnetic field annihilation and reconnection driven by femtosecond lasers in inhomogeneous plasma

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中国科学：物理学、力学、天文学英文版 2017年第11期60卷 68-75页

作者： YouYuan Wang FeiYu Li Min Chen SuMing Weng QuanMing Lu QuanLi Dong ZhengMing Sheng Jie Zhang Key Laboratory for Laser Plasmas (Ministry of Education) and School of physics and Astronomy Shanghai Jiao Tong University Collaborative Innovation Center of IFSA (CICIFSA) Shanghai Jiao Tong University scottish universities physics alliance (SUPA) Department of PhysicsUniversity of Strathclyde Key Lab of Geospace Environment Chinese Academy of Sciences Department of Geophysics and Planetary Science University of Science and Technology of China School of physics and Optoelectronic Engineering Ludong University

The process of fast magnetic reconnection driven by intense ultra-short laser pulses in underdense plasma is investigated by particle-in-cell simulations. In the wakefield of such laser pulses, quasi-static magnetic fields at a few mega-Gauss are generated due to nonvanishing cross product ▽(n/) × p. Excited in an inhomogeneous plasma of decreasing density, the quasi-static magnetic field structure is shown to drift quickly both in lateral and longitudinal directions. When two parallel-propagating laser pulses with close focal spot separation are used, such field drifts can develop into magnetic reconnection(annihilation) in their overlapping region, resulting in the conversion of magnetic energy to kinetic energy of particles. The reconnection rate is found to be much higher than the value obtained in the Hall magnetic reconnection model. Our work proposes a potential way to study magnetic reconnection-related physics with short-pulse lasers of terawatt peak power only.

关键词：非均匀等离子体准静态磁场激光驱动湮灭飞秒超短超强激光稀薄等离子体粒子模拟

Review on the temperature memory effect in shape memory alloys

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International Journal of Smart and Nano Materials 2011年第3期2卷 101-119页

作者： Zhiguo Wang Xiaotao Zu Yongquing Fu Department of Applied physics University of Electronic Science and Technology of ChinaChengdu610054China Thin Film Centre Scottish Union of Physics Alliance(SUPA)University of West of ScotlandPaisleyPA12BE UK

Shape memory alloys(SMAs)are well known for their unique shape memory effect(SME)and superelasticity(SE)behavior.The SME and SE have been extensively investigated in past decades due to their potential use in many applications,especially for smart materials.The unique effects of the SME and SE originate from martensitic transformation and its reverse transformation.Apart from the SME and SE,SMAs also exhibit a unique property of memorizing the point of interruption of martensite to parent phase transformation.If a reverse transformation of a SMA is arrested at a temperature between reverse transformation start temperature(As)and reverse transformation finish temperature(Af),a kinetic stop will appear in the next complete transformation cycle.The kinetic stop temperature is a‘memory’of the previous arrested temperature.This unique phenomenon in SMAs is called temperature memory effect(TME).The TME can be wiped out by heating the SMAs to a temperature higher than Af.The TME is a specific characteristic of the SMAs,which can be observed in TiNi-based and Cu-based alloys.TME can also occur in the R-phase transformation.However,the TME in the R-phase transformation is much weaker than that in the martensite to parent transformation.The decrease of elastic energy after incomplete cycle on heating procedure and the motion of domain walls have significant contributions to the TME.In this paper,the TME in the TiNi-based and Cu-based alloys including wires,slabs and films is characterized by electronic-resistance,elongation and DSC methods.The mechanism of the TME is discussed.

关键词： temperature memory effect shape memory alloys

Energy autonomous electronic skin

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npj Flexible Electronics 2019年第1期3卷 1-24页

作者： Carlos García Núñez Libu Manjakkal Ravinder Dahiya Bendable Electronics and Sensing Technologies(BEST)Group School of EngineeringUniversity of GlasgowG128QQ GlasgowUK scottish universities physics alliance(SUPA) Institute of Thin FilmsSensors&Imaging(TFSI)University of the West of ScotlandPaisley PA12BEUK

Energy autonomy is key to the next generation portable and wearable systems for several applications.Among these,the electronic-skin or e-skin is currently a matter of intensive investigations due to its wider applicability in areas,ranging from robotics to digital health,fashion and internet of things(IoT).The high density of multiple types of electronic components(e.***.sensors,actuators,electronics,etc.)required in e-skin,and the need to power them without adding heavy batteries,have fuelled the development of compact flexible energy systems to realize self-powered or energy-autonomous e-skin.The compact and wearable energy systems consisting of energy harvesters,energy storage devices,low-power electronics and efficient/wireless power transfer-based technologies,are expected to revolutionize the market for wearable systems and in particular for e-skin.This paper reviews the development in the field of self-powered e-skin,particularly focussing on the available energy-harvesting technologies,high capacity energy storage devices,and high efficiency power transmission systems.The paper highlights the key challenges,critical design strategies,and most promising materials for the development of an energy-autonomous e-skin for robotics,prosthetics and wearable systems.This paper will complement other reviews on e-skin,which have focussed on the type of sensors and electronics components.

关键词： electronic autonomous harvesting

高压下稳定的S_(3)O_(4):“硫过量”问题的启示

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Science Bulletin 2022年第9期67卷 971-976,M0004页

作者： Siyu Liu Pengyue Gao Andreas Hermann Guochun Yang Jian Lu Yanming Ma Ho-Kwang Mao Yanchao Wang These authors contributed equally to this work.a State Key Laboratory ofSuperhard Materials&International Center of Computational Method and Software College of PhysicsJilin UniversityChangchun 130012China Centre for Science at Extreme Conditions and scottish universities physics alliance School of Physics and AstronomyThe University of EdinburghEdinburgh EH93FDUK State Key Laboratory of Metastable Materials Science&Technology and Key Laboratory for Microstructural Material physics of Hebei Province School of ScienceYanshan UniversityQinhuangdao 066004China International Center of Future Science Jilin UniversityChangchun 130012China Center for High Pressure Science and Technology Advanced Research Beijing 100094China

人们发现火山喷发释放出的硫含量比前期估测火山喷发溶体中所容纳的硫高出了几个数量级,这就是火山喷发的“硫过量”问题.经过多年的研究,关于过量硫的来源问题人们提出了多种可能,但仍是一个谜团.本工作利用自主发展的CALYPSO晶体结构... 详细信息

人们发现火山喷发释放出的硫含量比前期估测火山喷发溶体中所容纳的硫高出了几个数量级,这就是火山喷发的“硫过量”问题.经过多年的研究,关于过量硫的来源问题人们提出了多种可能,但仍是一个谜团.本工作利用自主发展的CALYPSO晶体结构预测方法结合第一性原理计算,预言了一种新型硫氧化合物S_(3)O_(4).该化合物包含S(+Ⅱ)和S(+Ⅳ)混合价态,并且在79 GPa以上的压力条件下可以稳定存在.第一性原理计算表明,在深地幔的高压条件下,S_(3)O_(4)可以通过硫酸盐和硫化物与铁和针铁矿经氧化还原反应生成,并在地球浅层压力条件下可以分解为SO2和S单质.因此,本工作预言的S_(3)O_(4)是促进含硫矿物分解产生SO2的关键中间化合物.研究工作为解决火山喷发过程中的“硫过量”问题提供了新的思路,同时也为理解地球表面和下地幔深部之间的硫交换提供了重要的理论储备.

关键词：火山喷发地球表面第一性原理计算中间化合物针铁矿氧化还原反应矿物分解下地幔

Q-switched pulse generation from an all-f iber distributed Bragg reflector laser using graphene as saturable absorber

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Chinese Optics Letters 2013年第7期11卷 46-49页

作者： H. Ahmad F. D. Muhammad M. Z. Zulkifli S. W. Harun Photonics Research Centre Department of Physics University of Malaya Nanotechnology Research alliance Universiti Teknologi Malaysia

A Q-switched distributed Bragg reflector fiber laser using a graphene passive saturable absorber is proposed in a cavity consisting of a fiber Bragg grating and Faraday rotator mirror as end mirrors, together with a highly doped erbium-doped fiber as a gain source. The laser has a Q-switched threshold of about 28 mW and a tunable repetition rate of 10.4-18.0 kHz with varying pump power. The shortest pulse width obtained from the system is 3.7 its, with a maximum pulse energy and peak power of 22.2 nJ and 3.4 mW, respectively.

关键词： DBR Q-switched pulse generation from an all-f iber distributed Bragg reflector laser using graphene as saturable absorber EDF kHz dBm Figure