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Hybrid of bulk NbC and layered Nb_(4)C_(3)MXene for tailoring the hydrogen storage kinetics and reversibility of Li-Mg-B-H composite:An experimental and theoretical study

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Journal of Materials Science & Technology 2024年第27期194卷 225-235页

作者： Haizhen Liu Liwen Lu Hui Luo Jiayi Deng Guangxu Li Hua Ning Yi Fan Cunke Huang Zhiqiang Lan Wenzheng Zhou Jin Guo Xinhua Wang Guangxi Novel Battery Materials Research Center of Engineering Technology Key Laboratory of Blue Energy and Systems Integration(Guangxi University)Education Department of Guangxi Zhuang Autonomous RegionSchool of Physical Science and TechnologyGuangxi UniversityNanning 530004China College of Mathematics and Physics Guangxi Minzu UniversityNanning 530006China Nanning Engineering Technology Research Center for Power Transmission System of New Energy Vehicle Transportation CollegeNanning UniversityNanning 530200China Department of Materials Science and Engineering Zhejiang UniversityHangzhou 310027China

The Li-Mg-B-H composite(2LiBH_(4)+MgH_(2))is acknowledged as a promising material for hydrogen storage due to its large hydrogen capacity(11.4 wt.%).However,the sluggish kinetics and poor reversibility make it difficult to be practically *** this work,the hydrogen storage performances of 2LiBH_(4)+MgH_(2)have been significantly improved by a hybrid of bulk NbC and layered Nb_(4)C_(3)MXene(denoted as“Nb-C”).The 2LiBH_(4)+MgH_(2)+6 wt.%Nb-C can release 8.5 wt.%H_(2)within 30 min at 400℃and the dehy-drogenated composite can absorb 9.3 wt.%H_(2)within 30 min at 350℃and 7.5 MPa H_(2).The reversible dehydrogenation capacity maintains at 8.4 wt.%after 24 cycles,with a capacity retention ratio of 95.4%.By contrast,the undoped 2LiBH_(4)+MgH_(2)suffers from serious capacity degradation,with the capacity decreased dramatically to 3.5 wt.%after 3 *** studies revealed that the doped com-posite has uniform particle and elemental distributions and possesses various multiphase interfaces of LiH/MgB_(2)/NbC/Nb_(4)C_(3),which is beneficial to hydrogen diffusion during the hydrogen uptake and release *** studies by first principle calculation presented an extended bond length of the Mg-H and B-H bonds in the 2LiBH_(4)+MgH_(2)+NbC system,which may also explain the improved hydrogen storage properties of 2LiBH_(4)+MgH_(2)by addition of *** work provides new insights into the role of transition metal carbides in regulating the Li-Mg-B-H hydrogen storage materials both experimentally and theoretically.

关键词： Hydrogen storage Lithium borohydride Magnesium hydride MXene NbC Nb_(4)C_(3)

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An adaptive frequency optimization method for credibility assessment of equipment digital twins in intelligent manufacturing 35

An adaptive frequency optimization method for credibility as...

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35th European Modeling and Simulation Symposium, EMSS 2023

作者： Lu, Han Zhang, Lin Ren, Lei Laili, Yuanjun Beihang University Beijing100191 China Engineering Research Center of Complex Product Advanced Manufacturing System Ministry of Education Beijing100191 China

ISBN: (纸本)9788885741881

To guarantee the effective equipment digital twin (DT) applications in intelligent manufacturing, the DT’s credibility must be properly assessed continuously. Pursuing a rather high assessment frequency would guarantee the accuracy of the credibility but would slow down the quantification process or consume too much computational resources. The dynamic credibility assessment of the real-time evolving DTs has comprehensive requirements for accuracy, rapidity, and cost. To achieve the dynamic balance, an adaptive assessment frequency optimization method is proposed. The optimal assessment frequency can be adjusted in real time using particle swarm optimization algorithms according to variable application requirements and working conditions. The influence of different frequency on the credibility of digital twins are analyzed based on experience from VV&A (Verification, Validation and Accreditation) methods in M&S (Modeling and Simulation). The method not only guarantees the accuracy and effectiveness of the assessment results, but also meets the assessment rapidity requirements and is relatively more economical. © 2023 The Authors.

关键词： Particle swarm optimization (PSO)

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Truthful Mechanism for Resource Allocation and Pricing in Vehicle-Assisted Mobile Edge Computing

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IEEE Transactions on Vehicular Technology 2025年第5期74卷 8171-8186页

作者： Liu, Xi Liu, Jun Li, Weidong Qujing Normal University Key Laboratory of Intelligent Sensor and System Design School of Information Engineering Qujing655001 China Qujing Normal University Engineering Research Center of Intelligent System and Advanced Materials Yunnan Province Universities Qujing655001 China Yunnan College of Business Management School of Education Kunming650000 China Yunnan University School of Mathematics and Statistics Kunming650504 China

Mobile edge computing (MEC) provides stable and powerful computing services, and vehicle computing provides rich sensing services. Therefore, we develop vehicle-assisted mobile edge computing (VAMEC), integrating MEC and vehicle computing to maximize their advantages and broaden their applications. We address the resource allocation and pricing problem in VAMEC, in which the vehicle, as a resource provider, collaborates with the MEC servers to provide services to users. To enable MEC servers and vehicles to work in cooperation, we propose a mixed auction model that consists of two-step auctions: the first one-way auction and the second double auction. We consider three types of users based on their characteristics, where users participate in different auctions depending on the types. Users and vehicles are self-interested and may submit untrue values to harm the system's profits. Therefore, we propose the overall truthfulness for the mixed auction model, that is users or vehicles that cannot obtain higher utility by declaring untrue values regardless of which auction they participate in. To the best of our knowledge, this is the first study proposing the overall truthfulness and showing how to design the mechanism that achieves it. We then propose an overall truthfulness mechanism and show it achieves individual rationality, budget balance, and consumer sovereignty. Simulation results indicate that the proposed mechanism can increase social welfare by at least 24%, compared with other mechanisms. © 1967-2012 IEEE.

关键词： Mobile edge computing

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Real-Time Traffic Management of High-Speed Trains: A Novel Approach Combining Optimization with Machine Learning

Real-Time Traffic Management of High-Speed Trains: A Novel A...

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2024 China Automation Congress, CAC 2024

作者： Li, Chong Yin, Jiateng Ma, Lin Tang, Tao State Key Laboratory of Advanced Rail Autonomous Operation Beijing Jiaotong University Beijing China National Engineering Research Center of Rail Transportation Operation and Control System Beijing Jiaotong University Beijing China

ISBN: (纸本)9798350368604

The real-time traffic control of high-speed trains (HSTs) is an important task in railway networks to reduce the delay time of trains in case of unexpected disruptions. Traditional approaches are based on mixed-integer programming (MILP) formulations to be solved by optimization methods such as branch-and-bound (B&B), which however require a very long time in real-world problems. Our study introduces a novel methodology that employs machine learning (ML) techniques to accelerate the optimization of MILPs. Specifically, our approach develops a feedforward network, which can be trained off-line, to predict the optimal MILP parameter configurations for the control of HSTs. Additionally, we develop a differential evolution (DE) algorithm, which fine-tunes these parameters in response to dynamic conditions. We conduct numerical experiments based on the real-world data of Beijing-Zhangjiakou high-speed railway (BZHR). The results demonstrate that our ML-accelerated approach significantly outperforms traditional optimization methods, improving the solution performance by 21.47%. © 2024 IEEE.

关键词： Integer programming

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Constructing a fluorinated interface layer enriched with Ge nanoparticles and Li-Ge alloy for stable lithium metal anodes

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Nano research 2024年第6期17卷 5148-5158页

作者： Fulu Chu Jinwei Zhou Jiamin Liu Fengcheng Tang Liubin Song Feixiang Wu School of Metallurgy and Environment Engineering Research Center of the Ministry of Education for Advanced Battery MaterialsHunan Provincial Key Laboratory of Nonferrous Value-added MetallurgyCentral South UniversityChangsha 410083China Hunan Provincial Key Laboratory of Materials Protection for Electric Power and Transportation School of Chemistry and Chemical EngineeringChangsha University of Science and TechnologyChangsha 410004China School of Materials Science&Engineering University of JinanJinan 250022China

Lithium metal batteries(LMBs)based on metallic Li exhibit high energy density to be competent for advanced energy storage ***,the unstable solid electrolyte interphase(SEI)layer due to continuous decomposition of electrolytes,and the attendant problem of Li dendrite growth frustrate their commercialization ***,a hybrid SEI comprising abundant LiF,lithiophilic Li-Ge alloy,and Ge nanoparticles is constructed via a simple brush coating *** fluorinated interface layer with embedded Ge-containing components isolates the Li anode from the corrosive electrolyte and facilitates homogenous Li nucleation as well as uniform ***,the modified Li anode exhibits remarkable stability without notorious Li dendrites,delivering stable cycling lives of more than 1000 h for symmetric Li||Li cells and over 600 cycles for Li||Cu cells at 1 mA·cm^(−2).Moreover,the reinforced Li anodes endow multiple full-cell architectures with dramatically improved cyclability under different test *** work provides rational guidance to design an artificial hybrid SEI layer and would stimulate more ideas to solve the dendrite issue and promote the further development of advanced LMBs.

关键词： lithium metal anode artificial solid electrolyte interphase(SEI) dendrite suppression lithium fluoride Li-Ge alloy

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Spectral period doubling and encoding of dissipative optical solitons via gain control

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PhotoniX 2024年第1期5卷 290-305页

作者： Kangwen Yang Yi Zhou Yuqing Ling Kevin K.Tsia Heping Zeng Kenneth K.Y.Wong Shanghai Key Laboratory of Modern Optical System and Engineering Research Center of Optical Instrument and SystemMinistry of EducationSchool of Optical Electrical and Computer EngineeringUniversity of Shanghai for Science and TechnologyShanghai 200093China Department of Electrical and Electronic Engineering The University of Hong KongHong KongChina Advanced Biomedical Instrumentation Centre Hong Kong Science ParkHong KongChina State Key Laboratory of Precision Spectroscopy East China Normal UniversityShanghai 200062China

Period-doubling bifurcation,as an intermediate state between order and chaos,is ubiquitous in all disciplines of nonlinear ***,previous experimental observations of period doubling in ultrafast fiber lasers are mainly restricted to self-sustained steady state,controllable manipulation and dynamic switching between period doubling and other intriguing dynamical states are still largely ***,we propose to expand the vision of dissipative soliton periodic doubling,which we illustrate experimentally by reporting original spontaneous,collisional,and controllable spectral period doubling in a polarization-maintaining ultrafast fiber ***,the spontaneous period doubling can be observed in both single-and *** mechanism of the switchable state and periodic doubling was revealed by numerical ***,state transformation of individual solitons can be resolved during the collision of triple solitons involving stationary,oscillating,and period ***,controllable deterministic switching between period doubling and other dynamical states,as well as exemplifying the application of period-doubling-based digital encoding,is achieved under programmable pump *** results open a new window for unveiling complex Hopf bifurcation in dissipative systems and bring useful insights into nonlinear science and applications.

关键词： Period doubling Mode locking Ultrafast fiber lasers

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3D free-assembly modular microfluidics inspired by movable type printing

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Microsystems & Nanoengineering 2023年第5期9卷 191-201页

作者： Shaoqi Huang Jiandong Wu Lulu Zheng Yan Long Junyi Chen Jianlang Li Bo Dai Francis Lin Songlin Zhuang Dawei Zhang Engineering Research Center of Optical Instrument and System the Ministry of EducationShanghai Key Laboratory of Modern Optical SystemUniversity of Shanghai for Science and TechnologyShanghai 200093China Institute of Biomedical and Health Engineering Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China Department of Physics and Astronomy University of ManitobaWinnipegMB R3T 2N2Canada

Reconfigurable modular microfluidics presents an opportunity for flexibly constructing prototypes of advanced microfluidic ***,the strategy of directly integrating modules cannot easily fulfill the requirements of common applications,e.g.,the incorporation of materials with biochemical compatibility and optical transparency and the execution of small batch production of disposable chips for laboratory trials and initial ***,we propose a manufacturing scheme inspired by the movable type printing technique to realize 3D free-assembly modular ***-layer 3D microfluidic structures can be produced by replicating the assembled molds.A library of modularized molds is presented for flow control,droplet generation and manipulation and cell trapping and *** addition,a variety of modularized attachments,including valves,light sources and microscopic cameras,have been developed with the capability to be mounted onto chips on *** systems,including those for concentration gradient generation,droplet-based microfluidics,cell trapping and drug screening,are *** scheme enables rapid prototyping of microfluidic systems and construction of on-chip research platforms,with the intent of achieving high efficiency of proof-of-concept tests and small batch manufacturing.

关键词： batch proof mounted

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Hydrolysis enhancing mechanisms of Mg-based alloys/hydrides from perspectives:Electrochemical corrosion,active sites,mass transfer,and kinetics

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Journal of Materials Science & Technology 2023年第32期163卷 1-16页

作者： Chaoling Wu Qin Huang Bingshou Gong Ji Zhou Guanghui Xia Fangnan He Yao Wang Yigang Yan Yungui Chen Department of Advanced Energy Materials College of Materials Science and EngineeringSichuan UniversityChengdu 610042China Institute of New Energy and Low-Carbon Technology Sichuan UniversityChengdu 610065China Engineering Research Center of Alternative Energy Materials&Devices Ministry of EducationChengdu 610064China Technology Innovation Center of Hydrogen Storage-Transportation and Fueling Equipments for State Market Regulation Chengdu 610000China

Hydrogen energy is considered to be an ideal new energy carrier in the 21st century due to its clean,environmentally friendly,renewable characteristics and high energy *** generation of hydrogen by hydrolysis of Mg-based alloys/hydrides has attracted extensive attention attributed to the high hydrogen yield,environmentally-benign by-products,high crust abundance,and well-developed industrial production of ***,in the hydrolysis process of Mg or MgH_(2)to generate hydrogen,the formed Mg(OH)_(2)passivation layer attaches to the surface of the active materials to prevent the reaction from *** improve the hydrolysis performance,a series of methods have been put *** this paper,focusing on the mechanisms of hydrogen generation by hydrolysis of Mg-based alloys/hydrides,we summarize the recent research progress from four different perspectives:electrochemical corrosion promotion by constructing galvanic cells,active sites increment by refining the particles,mass transfer enhancement by breaking Mg(OH)_(2)and corresponding kinetic improvement.

关键词： Hydrogen generation Hydrolysis Mg MgH2

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Efficient and stable hybrid perovskite-organic light-emitting diodes with external quantum efficiency exceeding 40 per cent

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Light(Science & Applications) 2024年第7期13卷 1364-1371页

作者： Lingmei Kong Yun Luo Qianqian Wu Xiangtian Xiao Yuanzhi Wang Guo Chen Jianhua Zhang Kai Wang Wallace CHChoy Yong-Biao Zhao Hongbo Li Takayuki Chiba Junji Kido Xuyong Yang Key Laboratory of Advanced Display and System Applications of Ministry of Education Shanghai UniversityShanghai 200072China. Institute of Nanoscience and Applications Department of Electrical and Electronic EngineeringSouthern University of Science and TechnologyShenzhen 518055China. Department of Electrical and Electronic Engineering The University of Hong KongHong KongChina. Department of Physics and Lakeside AR/VR Laboratory International Joint Research Center for Optoelectronic and Engineering ResearchYunnan UniversityKunming 650091China. Experimental Center of Advanced Materials School of Materials Science and EngineeringBeijing Institute of TechnologyBeijing 100081China. Graduate School of Organic Materials Science Frontier Center for Organic MaterialsYamagata University4-3-16 JonanYonezawa 992–8510Japan

Light-emitting diodes(LEDs)based on perovskite semiconductor materials with tunable emission wavelength in visible light range as well as narrow linewidth are potential competitors among current light-emitting display technologies,but still suffer from severe instability driven by electric ***,we develop a stable,efficient and highcolor purity hybrid LED with a tandem structure by combining the perovskite LED and the commercial organic LED technologies to accelerate the practical application of *** LED and organic LED with close photoluminescence peak are selected to maximize photon emission without photon reabsorption and to achieve the narrowed emission *** designing an efficient interconnecting layer with p-type interface doping that provides good opto-electric coupling and reduces Joule heating,the resulting green emitting hybrid LED shows a narrow linewidth of around 30 nm,a peak luminance of over 176,000 cd m^(−2),a maximum external quantum efficiency of over 40%,and an operational half-lifetime of over 42,000 h.

关键词： diodes narrow quantum

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Small-Target Infrastructure Detection with Spatial Tracking and Multi-Level Feature Extraction of Railway Track Scenes

Small-Target Infrastructure Detection with Spatial Tracking ...

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2024 International Conference on Intelligent Communication, Sensing and Electromagnetics, ICSE 2024

作者： Du, Heng Cang, Huaiming Bai, Yiwen Wang, Xinyi Beijing Elephant Technology Co. Ltd Beijing China School of Transportation Science and Engineering Beihang University Beijing102206 China State Key Lab of Intelligent Transportation System Beijing100191 China School of Mechanical Engineering Tianjin University of Technology Tianjin Key Laboratory for Advanced Mechanical System Design and Intelligent Control Tianjin China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin300384 China

ISBN: (纸本)9798350354935

In the field of railway transportation, with the continuous improvement of train running speed and the continuous increase of operating mileage, it becomes particularly important to ensure the safety and integrity of small-Target infrastructure along the railway train. Although many small-Target detection methods have been proposed, the research on small-Target infrastructure detection along rail trains is very rare. To solve this problem, this paper proposes a small-Target infrastructure detection network with spatial tracking and multi-level feature extraction based on Yolov8n. The experimental results show that ST-YOLO has a 3.6% mAP improvement on the OSDaR23 dataset compared to the baseline Yolov8n, and shows significant advantages over other state-of-The-Art methods. © 2024 IEEE.

关键词： Railroads

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