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回火温度对55CrVNb弹簧钢组织与性能的影响

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材料热处理学报 2024年第7期45卷 154-162页

作者：谭玄关富禧宋新莉尤学文邱元元武汉科技大学省部共建耐火材料与冶金国家重点实验室湖北武汉430081

采用扫描电镜、透射电镜、X射线衍射仪和万能拉伸试验机等研究了不同温度回火对55CrVNb弹簧钢组织演变与力学性能影响。结果表明:55CrVNb弹簧钢淬火后的组织主要是板条与针状马氏体;在250~550℃回火50 min时,随着回火温度的升高,马氏体... 详细信息

采用扫描电镜、透射电镜、X射线衍射仪和万能拉伸试验机等研究了不同温度回火对55CrVNb弹簧钢组织演变与力学性能影响。结果表明:55CrVNb弹簧钢淬火后的组织主要是板条与针状马氏体;在250~550℃回火50 min时,随着回火温度的升高,马氏体板条模糊并逐渐消失,碳化物沿马氏体边界析出,数量增多尺寸也在增大,位错密度逐渐降低,固溶强化,位错强化、析出强化作用减弱,导致55CrVNb弹簧钢的强度降低,抗拉强度从2119.7 MPa下降至1228.0 MPa,屈服强度从1918.8 MPa下降至1188.9 MPa;随着回火温度升高,55CrVNb弹簧钢的伸长率呈现先升高后降低趋势,断裂类型由脆性断裂向韧性断裂转变;实验钢最佳的热处理工艺参数为:860℃奥氏体化30 min,450℃回火50 min。

关键词：弹簧钢回火温度组织力学性能

Double-layered skeleton of li alloy anchored on 3D metal foam enabling ultralong lifespan of li anode under high rate

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Chinese Chemical Letters 2024年第3期35卷 479-485页

作者： Chaohui Wei Zeyu Yao Jin Ruan Zhicui song Aijun Zhou Yingze song Donghuang Wang Jicheng Jiang xin Wang Jingze li Yangtze Delta Region Institute(Huzhou) University of Electronic Science and Technology of ChinaHuzhou 313000China School of Materials and Energy University of Electronic Science and Technology of ChinaChengdu 611731China State Key Laboratory of Environmental-Friendly Energy Materials Tianfu Institute of Research and InnovationSchool of Materials and ChemistrySouthwest University of Science and TechnologyMianyang 621010China

The high specific capacity and low negative electrochemical potential of lithium metal anodes(LMAs),may allow the energy density threshold of li metal batteries(LMBs)to be pushed ***,the existing detrimental issues,such as dendritic growth and volume expansion,have hindered the practical implementation of *** three-dimensional frameworks(e.g.,copper and nickel foam),have been regarded as one of the fundamental strategies to reduce the local current density,aiming to extend the Sand'***,the local environment far from the skeleton is almost the same as the typical plane li,due to macroporous space of metal ***,we built a double-layered 3D current collector of li alloy anchored on the metal foam,with micropores interconnected macropores,via a viable thermal infiltration and cooling *** to the excellent electronic and ionic conductivity coupled with favorable lithiophilicity,the li alloy can effectively reduce the nucleation barrier and enhance the li^(+)transportation rate,while the metal foam can role as the primary promotor to enlarge the surface area and buffer the dimensional ***,the li composite anode with hierarchical structure of primary and secondary scaffolds realized the even deposition behavior and minimum volume expansion,outputting preeminent prolonged cycling performances under high rate.

关键词： Double-layered skeleton li alloy 3D Metal foam Ultralong lifespan lithium metal batteries High rate

Enrichment of Chemical Element ^(7)li in the Rotating Red Clump Star

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Chinese Physics Letters 2024年第8期41卷 121-125页

作者： Fang-Wen Wu Han-Feng song Qing-li li Yun He xin-Yue Qu Zhuo Han College of Physics Guizhou UniversityGuiyang 550025China Geneva Observatory University of GenevaCH-1290 SauvernySwitzerland

About 2 percent of red clump stars are found to be the lithium-rich and thus the surface lithium increases obviously in some red clump *** physical mechanism of the lithium enrichment in these stars has not yet been explained satisfactorily by the evolutionary models of single *** flash induced internal gravity wave mixing(i.e.,IGW)could play a primary role in explaining the red clump star with lithium enrichment and it has a very significant impact on the internal structure and surface compositions of a *** can significantly increase the mixing efficiency of the internal gravity wave because the timescale for the enrichment event has been *** mixing can explain the observed behavior of lithium on red giant stars that are more luminosity than the RGB ***,it has a very small effect on the diffusion of elements because its diffusion coefficient is much smaller than the one of IGW induced mixing after the core helium flash.

关键词： flash stars lithium

li-ion Battery Failure Warning Methods for Energy-storage Systems

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Chinese Journal of Electrical Engineering 2024年第1期10卷 86-100页

作者： Peihao Wu Nawei Lyu Yuhang song xin Jiang Yang Jin School of Electrical and Information Engineering Zhengzhou UniversityZhengzhou 450001China

Energy-storage technologies based on lithium-ion batteries are advancing ***,the occurrence of thermal runaway in batteries under extreme operating conditions poses serious safety concerns and potentially leads to severe *** address the detection and early warning of battery thermal runaway faults,this study conducted a comprehensive review of recent advances in lithium battery fault monitoring and early warning in energy-storage systems from various physical *** focus was electrical,thermal,acoustic,and mechanical aspects,which provide effective insights for energy-storage system safety enhancement.

关键词： lithium-ion batteries energy-storage systems thermal runaway characteristic signals fault warning

Influence of Sub-Cloud Secondary Evaporation Effects on the Stable Isotopes in Precipitation of Urumqi Glacier No.1,Eastern Tianshan

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Journal of Earth Science 2024年第1期35卷 177-189页

作者： Mengyuan song Zhongqin li Feiteng Wang xin Zhang State Key Laboratory of Cryospheric Sciences Northwest Institute of Eco-Environment and ResourcesTianshan Glaciological StationChinese Academy of SciencesLanzhou 730000China College of Geography and Environmental Science Northwest Normal UniversityLanzhou 730000China College of Sciences Shihezi UniversityShihezi 832000China

In arid regions,the stable hydrogen and oxygen isotopic composition in raindrops is often modified by sub-cloud secondary evaporation when they descend from cloud base to ground through the unsaturated *** a result of kinetic fractionation,the slope and intercept of the δ^(2)H-δ^(18)O correlation equation *** variation of deuterium excess from cloud base to the ground is often used to quantitatively evaluate the influence of secondary evaporation effect on isotopes in *** on the event-based precipitation samples collected at Urumqi Glacier No.1,eastern Tianshan during four-year observation,the existence and impact of secondary evaporation effects were analyzed by the methods of isotope-evaporation *** high air temperature,small raindrop diameter and precipitation amount,and low relative humidity conditions,the remaining rate of raindrops is small and the change of deuterium excess is large relatively,and the slope and intercept of δ^(2)H-δ^(18)O correlation equation are much lower than those of Global Meteoric Water line,which mean that the influence secondary evaporation on precipitation *** on the conditions of low air temperature,high relative humidity,heavy rainfall,and large raindrop diameter,the change of deuterium excess is small relatively and the remaining rate of raindrops is large,and the slope and intercept of δ^(2)H-δ^(18)O correlation equation increase,the secondary evaporation is *** isotope-evaporation model described a good linear correlation between changes of deuterium excess and evaporation proportion with the slope of 0.90‰/%,which indicated that an increase of 1%in evaporation may result in a decrease of deuterium excess about 0.90‰.

关键词： stable isotopes meteoric water line deuterium excess sub-cloud secondary evaporation effect precipitation glaciers

Efficient capture of difluorocarbene by pyridinium 1,4-zwitterionic thiolates:A concise synthesis of difluoromethylene-containing 1,4-thiazine derivatives

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Chinese Chemical Letters 2024年第4期35卷 367-370页

作者： Zhiwei Chen Heyun Sheng Xue li Menghan Chen xin li Qiuling song Institute of Next Generation Matter Transformation College of Materials Science&Engineering and College of Chemical Engineering at Huaqiao UniversityXiamen 361021China Fujian University Key Laboratory of Molecule Synthesis and Function Discovery College of ChemistryFuzhou UniversityFuzhou 350108China State Key Laboratory of Organometallic Chemistry and Key Laboratory of Organofluorine Chemistry Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032China

A practical method for the construction of difluoromethylene-containing 1,4-thiazine moieties using readily available diethyl bromodifluoromethanephosphonate(BrCF_(2)PO(OEt)_(2))as difluorocarbene precusor has been *** transformation features the efficient capture of difluorocarbene by pyridinium 1,4-zwitterionic thiolates.A series of structurally novel and functionalized difluoromethylene-containing 1,4-thiazine derivatives were thus synthesized in good yields.

关键词： Difluoromethylene Pyridinium 1 4-zwitterionic thiolates 1 4-Thiazine derivatives

Interfacial friction effects on sealing performances of elastomer packer

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Petroleum Science 2024年第3期21卷 2037-2047页

作者： Peng-Cheng Wang Ming-Hui Chen Jim Jenkinson Yong-xin song li Sun Department of Mechanical Engineering University of HoustonHoustonTX77024USA Guren Nanomaterials Suzhou215127JiangsuChina Department of Marine Engineering Dalian Maritime UniversityDalian116026LiaoningChina

Elastomer sealing performance is of critical importance for downhole tools application including the use of fracturing(Frac)plugs during multi-stage hydraulic *** practice sealing performances of such plugs are normally evaluated through pressure tests,and in numerical simulation studies,maximum contact stress,average contact stress and contact length data are used to determine sealing quality between a packer and *** previous studies,the impact of friction forces on sealing performance is often *** work aims to fill this knowledge gap in determining the influence of friction forces on elastomer packer sealing *** first determined the most appropriate constitutive hyperelastic model for the elastomers used in frac *** we compared analytical calculation results with Finite Element Analysis simulation using a simplified tubular geometry and showed the significant influences on interfacial friction on elastomer packer stress distribution,deformation,and contact stress after *** the demonstration of validity of FEA method,we conducted systematic numerical simulation studies to show how the interfacial friction coefficients can affect the maximum contact stress,average contact stress,contact stress distribution,and maximum mises stress for an actual packer used in plug *** addition,we also demonstrated how the groove in a packer can affect packer deformation and evolvement during setting with the consideration of interfacial *** study underscores the critical role that friction forces play in Frac plug performance and provides a new dimension for optimizing packer design by controlling interfacial interactions at the packer contact surfaces.

关键词： Elastomer seal Friction Sealing performance Contact stress

Analysis of China’s PM_(2.5)and ozone coordinated control strategy based on the observation data from 2015 to 2020

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Journal of Environmental Sciences 2024年第4期138卷 385-394页

作者： liuwei Kong Mengdi song xin li Ying liu Sihua Lu limin Zeng Yuanhang Zhang State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences and EngineeringPeking UniversityBeijing 100871China

The coordinated control of PM_(2.5)and ozone has become the strategic goal of national air pollution *** the gradual decline in PM_(2.5)concentration and the aggravation of ozone pollution,a better understanding of the coordinated control of PM_(2.5)and ozone is urgently ***,we collected and sorted air pollutant data for 337 cities from 2015 to 2020 to explore the characteristics of PM_(2.5)and ozone pollution based on China’s five major air pollution *** results show that it is necessary to continue to strengthen the emission reduction in PM_(2.5)and ozone precursors,and control NO_(x) and VOCs while promoting a dramatic emission reduction in PM_(2.5).The primary method of curbing ozone pollution is to strengthen the emission control of VOCs,with a long-term strategy of achieving substantial emission reductions in NO_(x),because VOCs and NO_(x) are also precursors to PM_(2.5);hence,their reductions also contribute to the reduction in PM_(2.5).Therefore,the implementation of a multipollutant emission reduction control strategy aimed at the prevention and control of PM_(2.5)and ozone pollution is the only means to realize the coordinated control of PM_(2.5)and ozone.

关键词： PM_(2.5) Ozone Coordinated control Multipollutant reduction

Engineering g-C_(3)N_(4)based materials for advanced photocatalysis:Recent advances

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Green Energy & Environment 2024年第2期9卷 166-197页

作者： xin-lian song Lei Chen li-Jiao Gao Jin-Tao Ren Zhong-Yong Yuan National Institute for Advanced Materials School of Materials Science and EngineeringSmart Sensing Interdisciplinary Science CenterNankai UniversityTianjin300350China Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education) Nankai UniversityTianjin300071China

Photocatalysis driven by abundant yet intermittent solar energy has considerable potential in renewable energy generation and environmental *** outstanding electronic structure and physicochemical properties of graphitic carbon nitride(g-C_(3)N_(4)),together with unique metal-free characteristic,make them ideal candidates for advanced photocatalysts *** review summarizes the up-to-date advances on g-C_(3)N_(4)based photocatalysts from ingenious-design strategies and diversified photocatalytic ***,the advantages,fabrication methods and limitations of each design strategy are systemically *** order to deeply comprehend the inner connection of theory–structure–performance upon g-C_(3)N_(4)based photocatalysts,structure/composition designs,corresponding photocatalytic activities and reaction mechanisms are jointly discussed,associated with introducing their photocatalytic applications toward water splitting,carbon dioxide/nitrogen reduction and pollutants degradation,***,the current challenges and future perspectives for g-C_(3)N_(4)based materials for photocatalysis are briefly *** design strategies and limitations are also instructive for constructing g-C_(3)N_(4) based materials in other energy and environment-related applications.

关键词： Graphitic carbon nitride g-C_(3)N_(4) Design strategies Photocatalysis Photocatalysts Reaction mechanism