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SSRN 2024年

作者： Xie, Wenlong Zhang, Zhengjie Gao, Xinlei Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin University of Technology Tianjin300384 China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of Technology China School of Transportation Science and engineering Beihang University Beijing100191 China Department of Mechanical Engineering Imperial College London LondonSW7 2AZ United Kingdom

As a core component of transportation electrification, lithium-ion batteries need to address two critical challenges: achieving high energy density and enabling fast charging. However, changes in electrode thickness could result in a trade-off between these two characteristics. Herein, the impact of electrode thickness on the electrochemical performance, thermal behavior, as well as energy and power density of LiNi0.8Co0.1Mn0.1O2(NCM)/graphite batteries are investigated through mathematical modeling. Underutilization of active materials of the thick electrode is identified as the primary limitation on rate capability, which can be attributed to the slow solid-state diffusion and poor electrolyte transport within the electrode, especially the enlarged concentration gradients in the solid phase and the lithium depletion in the electrolyte phase during high-rate charging. Evolutions of local current density and heat generation rate along the electrode thickness are compared, identifying the underlying mechanism of inducing uneven reaction kinetics inside the battery. The trade-off between the energy and power density as a function of electrode thickness is investigated based on the limitations of charge transfer and mass transport. Furthermore, the rate-limiting factors under various application requirements are elucidated. This study will provide guidance for the electrode design of high-energy-density batteries with fast-charging capabilities. © 2024, The Authors. All rights reserved.

关键词： Lithium-ion batteries

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Dual liquid/vapor-fed flame synthesis for the effective preparation of SiO2@YAlO3:Nd3+nanophosphors 38th

Dual liquid/vapor-fed flame synthesis for the effective prep...

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38th International Symposium on Combustion, 2021

作者： Wu, Zeyun Zhang, Yiyang Zhao, Xiaofan Wang, Hongyan Li, Shuiqing Key Laboratory for Thermal Science and Power Engineering of Ministry of Education Department of Energy and Power Engineering Tsinghua University Beijing 100084 China Key Laboratory of Advanced Reactor Engineering and Safety of Ministry of Education Collaborative Innovation Center of Advanced Nuclear Energy Technology Institute of Nuclear and New Energy Technology Tsinghua University Beijing 100084 China College of Advanced Interdisciplinary Studies National University of Defense Technology Changsha 410073 China

Yttrium aluminum oxide YAlO3 is an attractive laser host material for lanthanide ions like Nd3+. In this paper, a dual liquid/vapor-fed flame synthesis (DLVF) system is developed for investigating the role of SiO2 coating on flame-made YAlO3:Nd3+ nanophosphors. The hexamethyldisiloxane (HDMSO) vapor is flexibly fed into the YAlO3:Nd3+ flame spray flow at different positions and molar ratios. We find that the introduction of SiO2 coating dramatically improves the crystallinity of YAlO3:Nd3+cores because of the heat-insulation effect and nearly doubles the fluorescence intensity. Through a timescale analysis, we demonstrate that the best timing for coating injection is when the small particles have already been formed but not heavily aggregated. An early injection could result in segregated SiO2 particles and some impurities like Al2SiO5, while a delayed injection leads to the coating of SiO2 on the entire aggregates instead of on individual particles. Experiments of different coating ratios show that the coating ratio 1:1 of Si:(Y+Nd) produces the best crystallinity and strongest fluorescence intensity. Further increase of the coating ratio does not show any improvements of the crystallinity, and may even causes the decrease of the relative fraction of Nd3+ ions. Compared with YAG:Nd3+ bulk materials (with a typical optimum doping concentration 1.1mol%) and uncoated YAlO3:Nd3+ nanophosphors (with an optimum doping concentration 2 mol%), the SiO2 coating promotes the optimum Nd3+ doping concentration up to 3 mol%. © 2020 Elsevier Ltd.

关键词： Fluorescence

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Unraveling the adsorption and diffusion behavior of H and O atoms at Zr(0001) surface doped with a Nb/Sn atom: A first-principles study

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Heliyon 2025年第4期11卷 e42376页

作者： Pan, Rongjian Tang, Aitao Qin, Jiantao Wang, Qingqing Wu, Lu The First Sub-Institute Nuclear Power Institute of China Sichuan Chengdu 610005 China Collaborative Innovation Center of Chemistry for Energy Material Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials Key Laboratory of Computational Physical Science Department of Chemistry Fudan University Shanghai 200433 China College of Materials Science and Engineering Chongqing University Chongqing 400044 China National Key Laboratory of Nuclear Reactor Technology Nuclear Power Institute of China Chengdu 610041 China

With the formation of a surface oxide or hydride layer of the zirconium alloy, the ductility of the nuclear rod decreases obviously. Thus, it is significant to develop a deeply understanding of this process, which may assist in future corrosion and hydrogen embrittlement resistance design for the zirconium alloy. A special focus of this work is an atomistic insight for unraveling the influence of doped alloying elements Nb/Sn on the early stages of oxide and hydride formation of zirconium alloys. The results show that for the effect of Nb/Sn on the adsorption of H at Zr(0001) surface, the adsorption energy of H on the surface of Zr alloys is tend to decrease with the addition of Nb, but for the addition of Sn, it is not significant. For the effect of Nb/Sn on the adsorption of O at Zr(0001) surface, the adsorption energy of O on the surface of Zr alloys is reduced with the addition of Nb and Sn, and the effect of Nb was more remarkable than that of Sn. In case of the diffusion barrier of H from Zr(0001) surface to the interior of Zr bulk, it is reduced with the addition of Nb in Zr(0001), while the addition of Sn does not change much. For the diffusion barrier of O, both are decreased with the addition of Nb or Sn in Zr(0001). © 2025

关键词： Adsorption Diffusion First-principles calculations Surface Zirconium

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Prediction of boiling crisis in a full-size rod bundle with spacer grids 14

Prediction of boiling crisis in a full-size rod bundle with ...

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14th International Nuclear Fuel Cycle Conference, GLOBAL 2019 and Light Water reactor Fuel Performance Conference, TOP FUEL 2019

作者： Li, Quan Li, Yuanming Avramova, M. Huang, Yongzhong Liu, Zhenhai Ma, Chao Qi, Feipeng Zhao, Bo Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu610213 China Department of Nuclear Engineering North Carolina State University NC27695 United States

In this paper, two-phase CFD approach is used to simulate the boiling crisis in PSBT rod bundle with spacer grids. The 5×5 rod bundle contains 17 spacer grids, which are finely modeled through UG code. Eulerian two-fluid model coupled with the extended wall boiling model is used to simulate the subcooled boiling flow. The used sub-models for nucleation site density and bubble departure diameter both take the effects of high pressure into consideration. The calculated surface averaged void fraction in the central four sub-channels shows good agreement with the experimental data at high void fraction conditions, while higher than the measured data at low void fraction conditions. Based on the two-phase simulations, the void fraction distribution in the plane section on which thermocouples are placed is used as the criteria for CHF prediction. The numerical simulation of boiling two-phase flow and prediction method of CHF provide new approach for the optimization of spacer grid and fuel assembly. Copyright © GLOBAL 2019 - International Nuclear Fuel Cycle Conference and TOP FUEL 2019 - Light Water reactor Fuel Performance *** rights reserved.

关键词： Forecasting

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Impact Time and Angle Control Guidance Based on Cubic Bézier Curves: Theory and Experiment

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SSRN 2024年

作者： Li, Heng Lv, Xiaokang Yu, Jianglong Zhang, Kun Wang, Yanyan Dong, Xiwang Institute of Artificial Intelligence Beihang University Beijing100191 China School of Automation Science and Electrical Engineering Science and Technology on Aircraft Control Laboratory Beihang University Beijing100191 China Institute of Unmanned System Beihang University Beijing100191 China School of Astronautics Beihang University Beihang University Beijing100191 China National Key Laboratory of Complex System Control and Intelligent Agent Cooperation Beijing100074 China

A trajectory-shaping guidance strategy with constraints on impact time, impact angle, and maximum lateral acceleration is proposed based on a cubic Bézier curve fitting method. Firstly, an optimal guidance model is formulated, in which the Bézier curves are employed to fit the guidance trajectory, ensuring compliance with the required constraints. The manipulation transforms the optimal guidance problem into an optimal Bézier guidance trajectory design problem and a trajectory tracking problem. Then, by parameterizing the Bézier curves and analyzing the trajectory constraints in detail, the optimal Bézier guidance trajectory design is transformed into optimizing the control parameters of the Bézier curves. Moreover, a multi-layer zeroth-order Adam trajectory optimization algorithm based on general and fine tuning is introduced to determine the control parameters without relying on gradient information. Subsequently, a hyperbolic tangent vector field path tracking guidance algorithm is proposed to follow the designed trajectory and fulfill the guidance missions. Finally, numerical simulations and equivalent physical experiments verify the effectiveness of the proposed guidance strategy. © 2024, The Authors. All rights reserved.

关键词： Trajectories

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Effects of land use and dissolved organic matter on pCO2 are dependent on stream orders and hydrological seasonality in a low-order karst river

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science of the Total Environment 2024年 957卷 177502页

作者： Ma, Yongmei Ni, Maofei Gu, Shijie Zhang, Liuqing Sun, Huaiwei Tang, Wei Li, Siyue Key Laboratory of Reservoir Aquatic Environment Chongqing Institute of Green and Intelligent Technology Chinese Academy of Sciences Chongqing400714 China College of Eco-Environmental Engineering Guizhou Minzu University Guiyang550025 China Institute of Environment and Ecology Shenzhen International Graduate School Tsinghua University Shenzhen China School of Civil and Hydraulic Engineering Huazhong University of Science and technology Wuhan430074 China Administration office for Wu Shan Dachang lake national wetland park Chongqing404700 China School of Environmental Ecology and Biological Engineering Institute of Changjiang Water Environment and Ecological Security Hubei Key Laboratory of Novel Reactor and Green Chemical Technology Wuhan Institute of Technology Wuhan430205 China

Human activities and stream accumulation influence carbon loadings, altering the distributions and characteristics of dissolved inorganic and organic carbon in rivers. It is widely recognized that such alterations affect dissolved organic matter (DOM) components, water environment and river carbon dioxide (CO2) degassing, however, the control factors by which land use/land cover (LULC) and DOM components regulate the partial pressure of CO2 (pCO2) are unclear. Here, in the Daning karst river system, an extensive investigation was presented to investigate the role of LULC and DOM components in influencing the spatial and temporal variability of pCO2, as well as to investigate the regulating effect of stream order and hydrological rhythm on this influence. DOM quality and pCO2 levels exhibited significant spatial and temporal variations. In the 3rd – 4th order streams, pCO2 was correlated with protein and lignin compounds in the wet period and with DOM molecular weight in the dry period. Relatively high protein-like components (54.83 % ∼ 71.84 %, on average) and biological index (0.86–0.90, on average) indicated notable autochthonous processes. Significant relationships between pCO2 and water quality parameters were observed in the 3rd – 4th order streams in the wet period, demonstrating the role of runoff and upstream accumulation. Farmland increased pCO2 levels in the 3rd – 4th order streams, whereas forests could potentially mitigate river CO2 saturation. River pCO2 was well predicted by LULC under extended circular buffers (1000 and 2000 m in diameter). This study demonstrated that DOM and LULC directly or indirectly affect pCO2 and that the influences are largely regulated by hydrological seasonality and stream orders, which is better for understanding aquatic CO2 drivers. © 2024 Elsevier B.V.

关键词： Carbon sequestration

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BAN: A Universal Paradigm for Cross-Scene Classification Under Noisy Annotations From RGB and Hyperspectral Remote Sensing Images

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IEEE Transactions on Geoscience and Remote Sensing 2025年 63卷

作者： Chen, Wentang Wen, Yibin Zheng, Juepeng Huang, Jianxi Fu, Haohuan Sun Yat-sen University School of Artificial Intelligence Zhuhai519082 China Zhejiang University State Key Laboratory of Fluid Power and Mechatronic Systems Engineering Research Center for Design Engineering and Digital Twin of Zhejiang Province School of Mechanical Engineering Robotics Institute Hangzhou310027 China Southwest Jiaotong University Faculty of Geosciences and Engineering Chengdu610032 China China Agricultural University College of Land Science and Technology Beijing100107 China Ministry of Agriculture and Rural Affairs Key Laboratory of Remote Sensing for Agri-Hazards Beijing100125 China Tsinghua University Tsinghua Shenzhen International Graduate School Shenzhen518071 China Tsinghua University Ministry of Education Key Laboratory for Earth System Modeling Department of Earth System Science Beijing100190 China National Supercomputer Center in Shenzhen Shenzhen518071 China

While domain adaptation (DA) methods have made significant strides in remote sensing community, most current works assume that the source domain labels are accurate. However, limited emphasis has been placed on the scenario where source data are mislabeled with noisy annotations, which is more common in real applications and referred to as noisy DA (NDA). This article formulates remote sensing cross-scene classification on NDA scenarios and proposes a novel network called bilateral adaptation network (BAN), which consists of two parts: 1) forward learning (FL), which utilizes a model learning from the noisy source domain and transfers knowledge to target domain;and 2) backward learning (BL), which utilizes a dual model to acquire knowledge from the target domain and transfer it to source domain. We conduct two parts alternately and adopt a symmetrical Kullback-Leibler (KL) loss to align predictions of the model and its dual model in the same domain. This interactive strategy is able to explore bilateral relationships between domains, implicitly reducing label noise in the source domain. In addition, BAN could serve as a universal paradigm to not only improve the existing NDA methods but also enhance recent DA approaches. Comprehensive evaluations on three publicly available RGB-band remote sensing datasets and two hyperspectral datasets validate the superior effectiveness of our proposed BAN. BAN improves the average accuracy by 6.70%-15.70% on RGB datasets and overall accuracy (OA) by 1.36%-3.14% on hyperspectral datasets with flip-20% noise compared to other state-of-the-art DA and NDA approaches. Promising results indicate the potential of our approach in tackling more general and practical problems with noisy source domain. © 2025 IEEE.

关键词： Contrastive Learning

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Electric Field-Controlled Damping Switches of Coupled Dirac Plasmons

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Physical Review Letters 2022年第23期129卷 237402-237402页

作者： Huayang Zhang Xiaodong Fan Dongli Wang Dongbo Zhang Xiaoguang Li Changgan Zeng CAS Key Laboratory of Strongly-Coupled Quantum Matter Physics and Department of Physics University of Science and Technology of China Hefei Anhui 230026 China International Center for Quantum Design of Functional Materials (ICQD) Hefei National Research Center for Physical Sciences at the Microscale University of Science and Technology of China Hefei Anhui 230026 China Hefei National Laboratory University of Science and Technology of China Hefei Anhui 230088 China Institute for Advanced Study Shenzhen University Shenzhen Guangdong 518060 China

For quasiparticle systems, the control of the quasiparticle lifetime is an important goal, determining whether the related fascinating physics can be revealed in fundamental research and utilized in practical applications. Here, we use double-layer graphene with a boron nitride spacer as a model system to demonstrate that the lifetime of coupled Dirac plasmons can be remotely tuned by electric field-controlled damping pathways. Essentially, one of the graphene layers serves as an external damping amplifier whose efficiency can be controlled by the corresponding doping level. Through this damping switch, the damping rate of the plasmon can be actively tuned up to 1.7 fold. This Letter provides a prototype design to actively control the lifetime of graphene plasmons and also broadens our horizon for the damping control of other quasiparticle systems.

关键词： Atomic force microscopy Random phase approximation Scanning near-field optical microscopy Transport techniques

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Effect Analysis of Microwave Power Transmitting Background Noise on Pilot Signal Reception

Effect Analysis of Microwave Power Transmitting Background N...

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International Conference on Microwave and Millimeter Wave technology Proceedings

作者： Shi-Wei Dong Ying Wang Yazhou Dong Feng Gao Weiwei Wang Yafeng Li Qiangli Xi Qiaoshan Zhang Zhengjun Li National Key Lab. of Science and Technology on Space Microwave CAST(Xi'an) Xi'an China Shaanxi Key Laboratory of Space Solar Power Station System School of Mechano-Electronic Engineering Xi'an China Deep Space Exploration Lab. Hefei China R&D and Marketing Department China Academy of Space Technology Beijing China Department of Antenna Engineering CAST(Xi'an) Xi'an China China Academy of Space Technology (Xi'an) Xi'an China

ISBN: (数字)9798350389968

ISBN: (纸本)9798350389975

The reception and process of the pilot signal determines the beam steering accuracy in retro-directive microwave power transmission (MPT) systems. The high power transmitting array presented high background noise level to the pilot signal receiver and thus reduced the signal-noise-ratio (SNR). Analysis method was put forward on the effect investigation. And a study case was discussed in this short paper, and the background noise effect was evaluated with respect to phase detection margin. This work addresses a fundamental problem and is expected to contribute to retro-directive MPT system design.

关键词： Microwave integrated circuits Direction-of-arrival estimation Power transmission Receivers Microwave theory and techniques Background noise Microwave FET integrated circuits

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An Enhanced MRC Framework with Triggers as Explanations for Named Entity Recognition

An Enhanced MRC Framework with Triggers as Explanations for ...

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IEEE Advanced Information Management,Communicates,Electronic and Automation Control Conference (IMCEC)

作者： Lin Li Xiao Huang Jie Ma Yijie Li School of Artificial Intelligence and Automation Huazhong University of Science and Technology (HUST) Wuhan China National Key Laboratory of Science and Technology on Multispectral Information Processing HUST Wuhan China China Ship Development and Design Center Wuhan China

ISBN: (纸本)9781665479691

An important challenge in named entity recognition (NER) is how to distinguish the correct meanings of polysemy entities in specific contexts. With the emergence of a large number of emerging entities and various new surface forms of entities, this challenge becomes more and more prominent. Another important challenge is that collecting annotations of named entities is usually expensive and laborious, especially in technical domains such as biomedical publications, financial reports, academic literature, etc. The key to solving above two challenges is that the model should be able to recognize entities utilizing information beyond entities. Entity trigger refers to a group of words that can act as explanation to recognize the positions and categories of entities. In view of the above two challenges, we propose an enhanced machine reading comprehension (MRC) framework with Triggers as Explanations for NER (i.e. MRC-TE). Specifically, our framework combines the information contained in entities and triggers into the same model through a multi-task learning method. Experimental results on two dataset CONLL2003 and BC5CDR demonstrates the effectiveness of our framework.

关键词： Learning systems Automation Annotations Biological system modeling Multitasking Information management Task analysis

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