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Correlation between hydration properties and electrochemical performances on Ln cation size effect in layered perovskite for protonic ceramic fuel cells

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Journal of Energy Chemistry 2024年第1期88卷 1-9,I0001页

作者： Inhyeok Cho Jiwon yun Boseok Seong Junseok Kim sun Hee Choi Ho-Il Ji Sihyuk Choi Department of Mechanical Engineering Kumoh National Institute of TechnologyGumi 39177GyeongbukRepublic of Korea Department of Aeronautics Mechanical and Electronic Convergence EngineeringKumoh National Institute of TechnologyGumi 39177GyeongbukRepublic of Korea Center for Energy Materials Research Korea Institute of Science and Technology(KIST)Seoul 02792Republic of Korea Center for Hydrogen and Fuel Cell Research Clean Technology Research DivisionKorea Institute of Science and Technology(KIST)Seoul 02792Republic of Korea Department of Energy and Environmental Engineering University of Science and TechnologySeoul 02792Republic of Korea Nanomaterials Science and Engineering Korea University of Science and Technology(UST)KIST CampusSeoul 02792Republic of Korea

PrBa_(0.5)Sr_(0.5)Co_(1.5)Fe_(0.5)O_(5+δ)(PrBSCF) has attracted much research interest as a potential triple ionic and electronic conductor(TIEC) electrode for protonic ceramic fuel cells(PCFCs). The chemical formula for Pr BSCF is AA'B_(2)O_(5+δ), with Pr(A-site) and Ba/Sr(A'-site) alternately stacked along the c-axis. Due to these structural features, the bulk oxygen ion diffusivity is significantly enhanced through the disorder-free channels in the PrO layer;thus, the A site cations(lanthanide ions) play a pivotal role in determining the overall electrochemical properties of layered perovskites. Consequently, previous research has predominantly focused on the electrical properties and oxygen bulk/surface kinetics of Ln cation effects,whereas the hydration properties for PCFC systems remain unidentified. Here, we thoroughly examined the proton uptake behavior and thermodynamic parameters for the hydration reaction to conclusively determine the changes in the electrochemical performances depending on LnBa_(0.5)Sr_(0.5)Co_(1.5)Fe_(0.5)O_(5+δ)(LnBSCF,Ln=Pr, Nd, and Gd) cathodes. At 500 ℃, the quantitative proton concentration of PrBSCF was 2.04 mol% and progressively decreased as the Ln cation size decreased. Similarly, the Gibbs free energy indicated that less energy was required for the formation of protonic defects in the order of Pr BSCF < Nd BSCF < Gd BSCF. To elucidate the close relationship between hydration properties and electrochemical performances in LnBSCF cathodes, PCFC single cell measurements and analysis of the distribution of relaxation time were further investigated.

关键词： Protonic ceramic fuel cell Cathode Triple ionic and electronic conductor Hydration property Proton uptake Gibbs free energy

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Characterizing leaf-deposited particles: Single-particle mass spectral analysis and comparison with naturally fallen particles

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Environmental Science and Ecotechnology 2024年第5期21卷 318-328页

作者： Dele Chen Hua-yun Xiao Ningxiao sun Jingli Yan Shan Yin School of Agriculture and Biology Shanghai Jiao Tong University800 Dongchuan Rd.Shanghai 200240China Shanghai Yangtze River Delta Eco-Environmental Change and Management Observation and Research Station Ministry of Science and TechnologyMinistry of Education800 Dongchuan Rd.Shanghai 200240China Shanghai Urban Forest Ecosystem Research Station National Forestry and Grassland Administration800 Dongchuan Rd.Shanghai 200240China

The size and composition of particulate matter(PM)are pivotal in determining its adverse health *** is important to understand PM's retention by plants to facilitate its atmospheric ***,the distinctions between the size and composition of naturally fallen PM(NFPM)and leaf-deposited PM(LDPM)are not *** we utilize a single-particle aerosol mass spectrometer,coupled with a PM resuspension chamber,to analyze these *** find that LDPM particles are 6.8 e97.3%larger than *** a neural network algorithm based on adaptive resonance theory,we have identified distinct compositional profiles:NFPM predominantly consists of organic carbon(OC;31.2%)and potassium-rich components(19.1%),whereas LDPM are largely composed of crustal species(53.9e60.6%).Interestingly,coniferous species retain higher OC content(11.5e13.7%)compared to broadleaved species(0.5e1.2%),while the levoglucosan content exhibit an opposite *** study highlights the active role of tree leaves in modifying PM composition beyond mere passive capture,advocating for a strategic approach to species selection in urban greening initiatives to enhance PM *** insights provide guidance for urban planners and environmentalists in implementing nature-based solutions to improve urban air quality.

关键词： Particulate matter Dry deposition Phytoremediation Size distribution Chemical composition Source apportionment

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Hypoxia-induced nuclear localization of ubiquinol-cytochrome-c reductase complex assembly factor 3(UQCC3)in hepatocellular carcinoma

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Signal Transduction and Targeted Therapy 2024年第8期9卷 3173-3175页

作者： yun Yang Yinhao Wei Yiying sun Yong Zhou Hanshuo Yang Department of Biotherapy Cancer Center and State Key Laboratory of BiotherapyWest China HospitalSichuan UniversityChengdu 610041China Department of Gastrointestinal Surgery West China HospitalSichuan UniversityChengdu 610041China

Dear Editor,The mitochondrion plays crucial roles in cellular energy generation and signaling *** studies have shown that nuclear-encoded mitochondrial proteins translocate into the nucleus to regulate cell function a... 详细信息

关键词： hepatocellular retrograde communicate

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Vision Transformers with Hierarchical Attention

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Machine Intelligence Research 2024年第4期21卷 670-683页

作者： yun Liu Yu-Huan Wu Guolei sun Le Zhang Ajad Chhatkuli Luc Van Gool Institute for Infocomm Research(I2R) A*STARSingapore 138632Singapore Institute of High Performance Computing(IHPC) A*STARSingapore 138632Singapore Computer Vision Lab ETH ZürichZürich 8092Switzerland School of Information and Communication Engineering University of Electronic Science and Technology of China(UESTC)Chengdu 611731China

This paper tackles the high computational/space complexity associated with multi-head self-attention(MHSA)in vanilla vision *** this end,we propose hierarchical MHSA(H-MHSA),a novel approach that computes self-attention in a hierarchical ***,we first divide the input image into patches as commonly done,and each patch is viewed as a ***,the proposed H-MHSA learns token relationships within local patches,serving as local relationship ***,the small patches are merged into larger ones,and H-MHSA models the global dependencies for the small number of the merged *** last,the local and global attentive features are aggregated to obtain features with powerful representation *** we only calculate attention for a limited number of tokens at each step,the computational load is reduced ***,H-MHSA can efficiently model global relationships among tokens without sacrificing fine-grained *** the H-MHSA module incorporated,we build a family of hierarchical-attention-based transformer networks,namely *** demonstrate the superiority of HAT-Net in scene understanding,we conduct extensive experiments on fundamental vision tasks,including image classification,semantic segmentation,object detection and instance ***,HAT-Net provides a new perspective for vision *** and pretrained models are available at https://***/yun-liu/HAT-Net.

关键词： Vision transformer hierarchical attention global attention local attention scene understanding.

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Rethinking Global Context in Crowd Counting

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Machine Intelligence Research 2024年第4期21卷 640-651页

作者： Guolei sun yun Liu Thomas Probst Danda Pani Paudel Nikola Popovic Luc Van Gool Computer Vision Lab ETH ZürichZürich 8092Switzerland Institute for Infocomm Research A*STARSingapore 138632Singapore Magic Leap Zürich 8050Switzerland

This paper investigates the role of global context for crowd ***,a pure transformer is used to extract features with global information from overlapping image *** by classification,we add a context token to the input sequence,to facilitate information exchange with tokens corresponding to image patches throughout transformer *** to the fact that transformers do not explicitly model the tried-and-true channel-wise interactions,we propose a token-attention module(TAM)to recalibrate encoded features through channel-wise attention informed by the context *** that,it is adopted to predict the total person count of the image through regression-token module(RTM).Extensive experiments on various datasets,including ShanghaiTech,UCFQNRF,JHU-CROWD++and NWPU,demonstrate that the proposed context extraction techniques can significantly improve the performanceover the baselines.

关键词： Crowd counting vision transformer global context attention density map.

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Understanding the cooperative effects in the catalysis of homodimeric fluoroacetate dehalogenase

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Science China Chemistry 2024年第7期67卷 2382-2391页

作者： Ke-Wei Chen Jia-Nan Chen Jun Zhang Chao Wang Tian-Yu sun yun-Dong Wu Key Laboratory of Computational Chemistry and Drug Design State Key Laboratory of Chemical OncogenomicSchool of Chemical Biology and BiotechnologyPeking University Shenzhen Graduate SchoolShenzhen 518055China Institute of Chemical Biology Shenzhen Bay LaboratoryShenzhen 518132China College of Chemistry and Molecular Engineering Peking UniversityBeijing 100871China Changping Laboratory Beijing 102200China

Fluoroacetate dehalogenases(FAcD),a homodimeric enzyme,catalyzes the conversion of fluoroacetic acid to glycolic acid(GoA).It has been proved that the enzyme has a half-of-the-site ***,its catalytic(C)subunit converts the first substrate to a covalent intermediate;then,the non-catalytic(NC)subunit binds a second substrate and promotes the conversion of the intermediate in the C subunit into the final *** the release of the product,the C subunit becomes the NC subunit,and the previous NC subunit becomes the C *** elucidate the detailed mechanism behind this cooperative catalysis,we have conducted microsecond-scale MD simulations along the reaction *** simulations indicate that the substrate in the NC subunit induces W185 and Y141 adopting an open conformation in the C *** opening of W185(C)facilitates the entry of catalytic water,enhancing the catalytic activity for product formation,while the opening of Y141(C)creates an unfavorable environment for product binding,promoting its *** interaction network analysis reveals that the substrate in the NC subunit can induce conformational changes through a conserved water chain at the interface.

关键词： enzyme catalysis molecular dynamics cooperative effect pre-reaction state

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The Boundedness of the Pullback Attractor for a 2D Micropolar Fluid Flows

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Acta Mathematicae Applicatae Sinica 2024年

作者： Wen-long sun Chun-lin LAI yun-yun LIANG School of information and mathematics Yangtze University

The purpose of this work is to investigate the boundedness of the pullback attractors for the micropolar fluid flows in two-dimensional unbounded domains. Exactly, the H1-boundedness and H2-boundedness of the pullback attractors are established when the external force F (t, x) has different regularity with respect to time variable, respectively.

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A machine learning framework for remaining useful lifetime prediction of li-ion batteries using diverse neural networks

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Energy and AI 2024年第1期15卷 102-135页

作者： Junghwan lee Huanli sun Yongshan Liu Xue Li First Automobile Works Group Corporation Research and Development Center No.1 Xinhongqi StreetChangchun130013JilinChina

Accurate prediction of the remaining useful life(RUL)of lithium-ion batteries(LIBs)is pivotal for enhancing their operational efficiency and safety in diverse *** operational advantages,precise RUL predictions can also expedite advancements in cell design and fast-charging methodologies,thereby reducing cycle testing *** artificial neural networks(ANNs)showing promise in this domain,determining the best-fit architecture across varied datasets and optimization approaches remains *** study introduces a machine learning framework for systematically evaluating multiple ANN *** only 30%of a training dataset derived from 124 LIBs subjected to various charging regimes,an extensive evaluation is conducted across 7 ANN *** architecture is optimized in terms of hyperparameters using this framework,a process that spans 145 days on an NVIDIA GeForce RTX 4090 *** optimizing each model to its best configuration,a fair and standardized basis for comparing their RUL predictions is *** research also examines the impact of different cycling windows on predictive *** a stratified partitioning technique underscores the significance of consistent dataset representation across ***,using only the features derived from individual charge–discharge cycles,our top-performing model,based on data from just 40 cycles,achieves a mean absolute percentage error of 10.7%.

关键词： Remaining useful life Artificial neural networks Li-ion batteries Deep neural networks Machine learning Hyperparameter optimization

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A novel silver-doped nickel oxide hole-selective contact for crystalline silicon heterojunction solar cells

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Frontiers of Chemical Science and Engineering 2024年第2期18卷 93-101页

作者： Junfeng Zhao Xudong Yang Zhongqing Zhang Shengpeng Xie Fangfang Liu Anjun Han Zhengxin Liu yun sun Wei Liu Key Laboratory of Photoelectronic Thin Film Devices and Technology of Tianjin Engineering Research Center of Thin Film Photoelectronic TechnologyInstitute of Photoelectronic Thin Film Devices and Technology of Nankai University(Ministry of Education)Tianjin 300350China Shanghai Institute of Microsystem and Information Technology Chinese Academy of SciencesShanghai 201800China

Based on its band alignment,p-type nickel oxide(NiO_(x))is an excellent candidate material for hole transport layers in crystalline silicon heterojunction solar cells,as it has a smallΔEV and largeΔEC with crystalline ***,to overcome the poor hole selectivity of stoichiometric NiO_(x) due to its low carrier concentration and conductivity,silver-doped nickel oxide(NiO_(x):Ag)hole transport layers with high carrier concentrations were prepared by co-sputtering high-purity silver sheets and pure NiO_(x) *** improved electrical conductivity of NiO_(x) was attributed to the holes generated by the Ag^(+)substituents for Ni^(2+),and moreover,the introduction of Ag^(+)also increased the amount of Ni^(3+)present,both of which increased the carrier concentration in NiO_(x).Ag^(+)doping also reduced the c-Si/NiO_(x) contact resistivity and improved the hole-selective contact with NiO_(x).Furthermore,the problems of particle clusters and interfacial defects on the surfaces of NiO_(x):Ag films were solved by UV-ozone oxidation and high-temperature annealing,which facilitated separation and transport of carriers at the c-Si/NiO_(x) *** constructed c-Si/NiO_(x):Ag solar cell exhibited an increase in open-circuit voltage from 490 to 596 mV and achieved a conversion efficiency of 14.4%.

关键词： band alignment nickel oxide hole transport layer silver-doped nickel oxide UV-ozone

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Ethyl acetate fraction of Sargassum pallidum extract attenuates particulate matter-induced oxidative stress and inflammation in keratinocytes and zebrafish

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Asian Pacific Journal of Tropical Biomedicine 2024年第4期14卷 137-146页

作者： Wook Chul Kim Ji-Won Park Bohyun yun WonWoo lee Kyung-Min Choi Seung-Hong lee Department of Medical Science Soonchunhyang UniversityAsan 31538Republic of Korea Honam National Institute of Biological Resources 99Gohadoan-gilMokpo-siJeollanam-do 58762Republic of Korea Department of Pharmaceutical Engineering Soonchunhyang UniversityAsan 31538Republic of Korea

Objective:To evaluate the effect of the ethyl acetate fraction derived from Sargassum pallidum extract against particulate matter(PM)-induced oxidative stress and inflammation in HaCaT cells and ***:HaCaT cells and zebrafish were used to evaluate the protective effects of the ethyl acetate fraction of Sargassum pallidum extract against PM-induced oxidative stress and *** production of nitric oxide(NO),intracellular ROS,prostaglandin E_(2)(PGE_(2)),and pro-inflammatory cytokines,and the expression levels of COX-2,iNOS,and NF-κB were evaluated in PM-induced HaCaT ***,the levels of ROS,NO,and lipid peroxidation were assessed in the PM-exposed zebrafish ***:The ethyl acetate fraction of Sargassum pallidum extract significantly decreased the production of NO,intracellular ROS,and PGE_(2) in PM-induced HaCaT *** addition,the fraction markedly suppressed the levels of pro-inflammatory cytokines and inhibited the expression levels of COX-2,iNOS,and NF-κ***,it displayed remarkable protective effects against PM-induced inflammatory response and oxidative stress,represented by the reduction of NO,ROS,and lipid peroxidation in ***:The ethyl acetate fraction of Sargassum pallidum extract exhibits a protective effect against PM-induced oxidative stress and inflammation both in vitro and in vivo and has the potential as a candidate for the development of pharmaceutical and cosmeceutical products.

关键词： Particulate matter Inflammation Oxidative stress Sargassum pallidum Ethyl acetate fraction Zebrafish

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