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Scuffing failure analysis based on a multiphysics coupling model and experimental verification

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Friction 2024年第6期12卷 1214-1234页

作者： Bugao LYU Xianghui MENG Jiabao yiN yi cui Chengen WANG School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai 200240China

General reductions in lubricant viscosities and increasing loads in machine components highlight the role of tribofilms in providing surface protection against ***,the relationship between the scuffing process and the growth and removal of tribofilm is not well *** this study,a multiphysics coupling model,which includes hydrodynamic lubrication,asperity contact,thermal effect,tribochemistry reaction,friction,and surface wear,was developed to capture the initiation of surface *** and experiments for a piston ring and cylinder liner contact were conducted following a step-load sequence under different temperature *** results show that high temperature and extreme load could induce the lubricant film collapse,which in turn triggers the breakdown of the tribofilm due to the significantly increased removal *** failures of both lubricant film and tribofilm progress instantaneously in a coupling way,which finally leads to severe scuffing.

关键词： scuffing failure tribofilm boundary lubrication multiphysics coupling effects

The impact of Internet access on household dietary quality:Evidence from rural China

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Journal of Integrative Agriculture 2024年第2期23卷 374-383页

作者： yi cui Qiran Zhao Thomas Glauben Wei Si College of Economics and Management China Agricultural UniversityBeijing 100083China Academy of Global Food Economics and Policy China Agricultural UniversityBeijing 100083China Leibniz Institute of Agricultural Development in Transition Economies(IAMO) Halle(Saale)06120Germany

Over the past few decades,the Internet has rapidly diffused across *** spread of the Internet has had a profound economic and social impact on Chinese rural *** research shows that Internet access significantly impacts agricultural production and improves smallholder farmers’*** these,the Internet can affect other dimensions of social ***,research about the impact of Internet access on dietary quality in rural China remains *** study utilizes multi-period panel data from Fixed Observation Point in rural China from 2009 to 2015 to estimate the impact of Internet access on dietary quality and food consumption of rural households and conducts a causal *** models with time and household fixed effects allow robust estimation while reducing potential issues of unobserved *** estimates show that Internet access has significantly increased rural household dietary quality(measured by the Chinese Diet Balance Index).Further research finds that Internet access has increased the consumption of animal products,such as aquatic and dairy *** also examine the underlying *** access improves dietary quality and food consumption mainly through increasing household income and food *** results encourage the promotion of Internet access as a valuable tool for nutritional improvements,especially in rural areas.

关键词： dietary quality fixed effect model Internet access rural China

Aging Mechanism and Life Estimation of Photovoltaic Inverter DC-link Capacitors in Alternating Humid and Thermal Environment

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Chinese Journal of Electrical Engineering 2024年第1期10卷 48-62页

作者： Quanyi Gao Shuaibing Li yi cui Yongqiang Kang Haiying Dong School of New Energy and Power Engineering Lanzhou Jiaotong UniversityLanzhou 730070China State Key Laboratory of Large Electric Drive System and Equipment Technology Tianshui 741000China School of Engineering University of Southern QueenslandSpringfield 4300Australia

DC-link capacitors play a vital role in managing ripple voltage and current in converters and various *** study focuses on exploring the aging characteristics of DC-link capacitors in alternating humid and thermal environments aligned with the operational conditions in photovoltaic and wind power *** to relevant power equipment standards,we designed a 24-h alternating humid and thermal aging environment tailored to the requirements of DC-link *** aging test platform is established,and 20 widely used metallized polypropylene film capacitors are selected for *** such as the capacitance,equivalent series resistance(ESR),and phase angle are assessed during aging,as well as the onset time and extent of aging at various *** study focuses on the aging mechanisms,analyzing electrode corrosion,the self-healing process,and dielectric *** the aging characteristics enabled us to calculate the lifespan of the capacitor and predict it under different degrees of capacitance *** results show that under alternating humid and thermal conditions,capacitance attenuation and ESR increase exhibit exponential nonlinearity,influenced by factors such as the oxidation and self-healing of capacitive metal electrodes,dielectric main-chain fracture,and crystal *** study underscores the pivotal role of encapsulation in determining the aging decay time.

关键词： DC-link capacitors aging mechanism life prediction metallized film capacitors

In-situ analysis and genetic investigation of Li-bearing minerals in McDermitt clay-type lithium deposit,Nevada,USA

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Acta Geochimica 2024年第3期43卷 478-488页

作者： yi cui Hanjie Wen Zhengbing Zhou Kunyue Ling Lin Xu Shirong Liu Fei Xu School of Earth Sciences East China University of TechnologyNanchang 330013China State Key Laboratory of Nuclear Resources and Environment East China University of TechnologyNanchang 330013China School of Earth Sciences and Resources Chang’an UniversityXi’an 710054China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China State Key Laboratory of Ore Deposit Geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang 550081China State Key Laboratory of Environmental Geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang 550081China

Clay-type Li deposits are poised to play a pivotal role in addressing the surging global demand for *** McDermitt clay-type Li deposit,located in Nevada,is the largest Li deposit in the United States,with Li hosted by a clay-rich sequence of smectite-dominated intervals and illite-dominated intervals,***,the occurrence of Li and the genesis of Li-bearing minerals within smectite-dominated intervals have not been thoroughly investigated in previous ***,we studied the mineralogy,the in-situ Li distribution,and the bonding environments of Li within the smectite intervals using a combination of instru-mental techniques including scanning electron microscope,transmission electron microscope,time-of-flight secondary ion mass spectrometry,and nuclear magnetic *** results indicate that the smectite exhibits low crystallinity characteristics of lacustrine clay authigenesis and is com-monly found tofill the interstices among volcanic minerals or envelop them;Li is mainly hosted by Mg-smectite rather than the volcanic *** the tuffaceous sediment samples,the volcanic glass has undergone a transformation,resulting in its complete disappearance and alteration into clay *** to the octahedral sites of Mg-smectite bounded in Li,it is referred to be *** interpret that the hectorite’s precipitation occurs in a high saline-alkaline water environment,a result of McDermitt *** conclusion can be supported by the coexistence of spherulitic calcite and ***,this study confirms hectorite as the main Li-bearing mineral and increases the understanding of the genetic model of hectorite formation in intracontinental caldera basins.

关键词： McDermitt caldera Lithium occurrence Tuffaceous sediments Mineralogy Hectorite neoformation

Palladium single atoms from melting nanoparticles on WO_(3-x) for boosted hydrogen evolution reaction

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Journal of Energy Chemistry 2024年第4期91卷 637-644页

作者： Zhongmiao Gong Zhigang Chen Hao Li Guang Yang Min Yuan Zhiyun Li Xueying Wan yi cui School of Nano-Tech and Nano-Bionics University of Science and Technology of ChinaHefei 230026AnhuiChina i-lab Vacuum Interconnected Nanotech WorkstationSuzhou Institute of Nano-Tech and Nano-BionicsChinese Academy of SciencesSuzhou 215123JiangsuChina School of Materials Science and Engineering Chongqing University of TechnologyChongqing 400054China Key Laboratory of Precision and Intelligent Chemistry School of Chemistry and Materials ScienceHefei National Research Center for Physical Sciences at the MicroscaleNational Synchrotron Radiation LaboratorySchool of Nuclear Science and TechnologyUniversity of Science and Technology of ChinaHefei 230026AnhuiChina

Surface-supported isolated atoms in single-atom catalysts(SACs)grant maximum utilization of metals in heterogeneous ***,we report a feasible pyrolysis strategy to synthesize Pd single atoms by thermally melting Pd nanoparticles on an oxygen-vacancy-rich tungsten-oxide matrix at reduction *** ambient pressure X-ray photoelectron spectroscopy was used to monitor the formation of zero-valence Pd single atoms and the increased metallic feature of WO_(3-x)***,the as-obtained zero-valence Pd single-atom catalyst exhibits a markedly boosted HER activity with a low overpotential(η_(10)=70 mV)at the current density of 10 mA/cm2and a small Tafel slope(b=68 mV/dec),nearly 150 mV and a 3,0-fold enhancement than those of Pd nanoparticles(η_(10)=220 mV,b=133 mV/dec)under the same *** addition,quasi in situ XPS results suggest the hydrogen spillover effect is more likely to occur on Pd single atoms during the electrochemical *** work may pave an interesting route for the rational design of highly-efficient single-atom catalysts,and the elucidation of corresponding enhanced reaction mechanisms by the utilization of advanced characterization techniques.

关键词： Pd WO_(3-x) Single-atom catalysts NAP-XPS HER

Existence of long-range magnetic order in Heisenberg spin nanoribbons with edge modification

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Communications in Theoretical Physics 2024年第7期76卷 134-144页

作者： Da-cheng Ma Ling-yi cui Chu-xiao Sun Xiao-dan Chi Zheng-Nan XianYu An Du College of Science Northeastern UniversityShenyang 110819China Department of Basic Science Dalian Naval AcademyDalian 116018China Department of Physics College of SciencesShenyang University of Chemical TechnologyShenyang 110142China National Frontiers Science Center for Industrial Intelligence and Systems Optimization Northeastern UniversityChina Key Laboratory of Data Analytics and Optimization for Smart Industry(Northeastern University) Ministry of EducationChina

Long-range magnetic order appears on a side decorated Heisenberg spin nanoribbon at nonzero temperature,although no spontaneous magnetization exists in a one-or two-dimensional isotropic Heisenberg model at any nonzero temperature according to the Mermin-Wagner *** use of the spin Green's function method,we calculated the magnetizations of Heisenberg nanoribbons decorated by side spins with single-ion anisotropy and found that the system exhibits a nonzero transition temperature,whether the decorated edge spins of the system link together or separate from each *** the width of the nanoribbon achieves infinite limit,the transition temperatures of the system tend to the same finite constant eventually whether one edge or both edges are decorated by side spins in the *** results reveal that the magnetism of a low-dimensional spin system is different from that of a threedimensional spin *** the single-ion anisotropy of edge spins in a Heisenberg spin nanoribbon can be modulated by an electric field experimentally,various useful long-range magnetic orders of the system can be *** work can provide a detailed theoretical basis for designing and fabricating next-generation low-dimensional magnetic random-access memory.

关键词： Nanoribbon magnetic anisotropy long-range magnetic order Heisenberg model transition temperature

Understanding the combustion behavior of electric bicycle batteries and unveiling its relationship with fire extinguishing

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Journal of Energy Chemistry 2024年第4期91卷 609-618页

作者： Zhanglong Yu Xueling Shen Ran Xu Zheng Wang Zengming Wan Mingyang Chen yi cui Yanyan Fang Xiaoli Ma China Automotive Battery Research Institute Co. Ltd.Beijing 101407China China Grinm Group Co. Ltd.Beijing 100088China Ministry of Industry and Information Technology Equipment Industry Development CenterBeijing 100846China Hefei Guoxuan High-tech Power energy Co. Ltd.Hefei 230000AnhuiChina

In this study,a detailed analysis of the combustion behaviors of the lithium iron phosphate(LFP)and lithium manganese oxide(LMO)batteries used in electric bicycles was *** research included quantitative measurements of the combustion duration,flame height,combustion temperature,heat release rate,and total heat *** results indicated that LMO batteries exhibited higher combustion temperatures of 600–700°C,flame heights of 70–75 cm,a significantly higher heat release rate of40.1 k W(12 Ah),and a total heat release of 1.04 MJ(12 Ah)compared to LFP batteries with the same *** on these experimental results,a normalized total heat release(NORTHR)parameter was proposed,demonstrating good universality for batteries with different *** this parameter,quantitative calculations and optimization of the extinguishing agent dosage were conducted for fires involving these two types of batteries,and the method was validated by extinguishing fires for these two types of battery packs with water-based extinguishing fluids.

关键词： Combustion behavior Electric bicycle Lithium-ion battery Fire extinguishing Normalized total heat release

Exploring the role of iron in Fe_(5)Ni_(4)S_(8)toward oxygen evolution through modulation of electronic orbital occupancy

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Journal of Energy Chemistry 2024年第5期92卷 52-62页

作者： Zhengyan Du Zeshuo Meng Haoteng Sun yifan Li Chao Jiang Yaxin Li Xiaoying Hu yi cui Shansheng Yu Hongwei Tian Key Laboratory of Automobile Materials of MOE School of Materials Science and EngineeringJilin UniversityChangchun 130012JilinChina College of Science and Laboratory of Materials Design and Quantum Simulation Changchun UniversityChangchun 130022JilinChina i-lab Vacuum Interconnected Nanotech Workstation(Nano-X)Suzhou Institute of Nano-Tech and Nano-BionicsChinese Academy of SciencesSuzhou 215123JiangsuChina Department of Chemistry Brown UniversityRI 02912United States

Ni-Fe-based catalysts are considered to be among the most active catalysts for the oxygen evolution reaction(OER)under alkaline conditions,with Fe playing a crucial ***,Fe leaching occurs during the reaction due to thermodynamic instability,which has resulted in conflicting reports within the literature regarding its *** clarify this point,we propose a strategy consisting of modulating the electronic orbital occupancy to suppress the extensive loss of Fe atoms during the OER *** calculations,in-situ X-ray photoelectron spectroscopy,molecular dynamics simulations,and a series of characterization showed that the stable presence of Fe not only accelerates the electron transfer process but also optimizes the reaction barriers of the oxygen evolution intermediates,promoting the phase transition of Fe_(5)Ni_(4)S_(8)to highly active catalytic *** modulated Fe_(5)Ni_(4)S_(8)-based pre-catalysts exhibit improved OER activity and long-term *** study provides a novel perspective for understanding the role of Fe in the OER process.

关键词： Oxygenevolution Fe_(5)Ni_(4)S_(8) Electronic orbital occupancy modulation Reconstruction dynamics

Semiclassical approach to spin dynamics of a ferromagnetic S = 1 chain

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Chinese Physics B 2024年第6期33卷 95-100页

作者：李承晨崔祎于伟强俞榕 Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials and Micro-nano Devices Renmin University of ChinaBeijing 100872China Key Laboratory of Quantum State Construction and Manipulation(Ministry of Education) Renmin University of ChinaBeijing 100872China

Motivated by recent experimental progress on the quasi-one-dimensional quantum magnet Ni Nb2O6, we study the spin dynamics of an S = 1 ferromagnetic Heisenberg chain with single-ion anisotropy by using a semiclassical molecular dynamics approach. This system undergoes a quantum phase transition from a ferromagnetic to a paramagnetic state under a transverse magnetic field, and the magnetic response reflecting this transition is well described by our semiclassical *** show that at low temperature the transverse component of the dynamical structure factor depicts clearly the magnon dispersion, and the longitudinal component exhibits two continua associated with single-and two-magnon excitations,respectively. These spin excitation spectra show interesting temperature dependence as effects of magnon interactions. Our findings shed light on the experimental detection of spin excitations in a large class of quasi-one-dimensional magnets.

关键词： one-dimensional ferromagnetism spin dynamics magnon excitation molecular dynamics