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Long-term tribocorrosion resistance and failure tolerance of multilayer carbon-based coatings

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Friction 2022年第10期10卷 1707-1721页

作者： Hao LI Linlin LIU Peng GUO Lili sun Jing WEI Yingrui LIU shuyu LI shuyuan WANG Kwang-Ryeol LEE Peiling KE Aiying WANG Key Laboratory of Marine Materials and Related Technologies Zhejiang Key Laboratory of Marine Materials and Protective TechnologiesNingbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingbo 315201China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Computational Science Center Korea Institute of Science and TechnologySeoul 136-791Republic of Korea

Current tribocorrosion research of metallic materials and their surface protective coatings mainly focuses on their short-term properties,with test time of 0.5‒2.0 h and a sliding distance 50‒500 m,which may significantly deviate from the practical long-term service condition and thus cause a catastrophe of marine equipments.In this study,three carbon-based multilayer coatings(Ti/DLC,TiC_(x)/DLC,and Ti‒TiC_(x)/DLC)were deposited on S32750 substrates,and both short-term and long-term tribocorrosion behaviors were investigated.The experimental results indicate that the coatings substantially improve the tribocorrosion resistance of the S32750 stainless steel.During the short-term tribocorrosion test,TiC_(x)/DLC exhibited the best tribocorrosion resistance owing to its high hardness.During the long-term tribocorrosion test,however,Ti‒TiC_(x)/DLC coating indicated the best anti-tribocorrosion performance owing to its excellent fracture toughness together with high hardness.Moreover,under 5 N,Ti‒TiC_(x)/DLC can withstand a long-term test of more than 24 h.Additionally,under a higher load of 20 N,the Ti‒TiC_(x)/DLC with a corresponding sliding distance of approximately 1,728 m maintained a low friction coefficient of approximately 0.06.However,the coating was completely worn out;this is attributable to the formation of tribocorrosion products consisting of graphitized carbon and nanocrystalline Fe_(x)O_(y).

关键词： DLC multilayer structure long-term tribocorrosion failure tolerance

Thermal runaway propagation behavior of the Cell-to-Pack battery system

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Journal of Energy Chemistry 2023年第9期84卷 162-172页

作者： Huaibin Wang Qinzheng Wang Zhenyang Zhao Changyong Jin Chengshan Xu Wensheng Huang Zhuchen Yuan shuyu Wang Yang Li Yanhong Zhao Junli sun Xuning Feng China People’s Police University LangFang 065000HebeiChina State Key Laboratory of Intelligent Green Vehicle and Mobility Tsinghua UniversityBeijing 100084China Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100084China Beijing Electric Vehicle Co.Ltd Beijing 100176China College of Mechanical Engineering University of Shanghai for Science and TechnologyShanghai 200093China

Structurally compact battery packs significantly improve the driving range of electric vehicles.Technologies like Cell-to-Pack increase energy density by 15%-20%.However,the safety implications of multiple tightly-packed battery cells still require in-depth research.This paper studies thermal runaway propagation behavior in a Cell-to-Pack system and assesses propagation speed relative to other systems.The investigation includes temperature response,extent of battery damage,pack structure deformation,chemical analysis of debris,and other considerations.Results suggest three typical patterns for the thermal runaway propagation process:ordered,disordered,and synchronous.The synchronous propagation pattern displayed the most severe damage,indicating energy release is the largest under the synchronous pattern.This study identifies battery deformation patterns,chemical characteristics of debris,and other observed factors that can both be applied to identify the cause of thermal runaway during accident investigations and help promote safer designs of large battery packs used in large-scale electric energy storage systems.

关键词： Energy storage Cell-to-Pack Lithium-ion battery Thermal runaway Battery safety

A preliminary study on measurements of black carbon in the atmosphere of northwest Qilian Shan

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Journal of Environmental Sciences 2012年第1期24卷 152-159页

作者： shuyu Zhao Jing Ming Cunde Xiao Weijun sun Xiang Qin State Key Laboratory of Cryospheric Sciences Cold and Arid Regions Environmental and Engineering Research InstituteChinese Academy of SciencesGansu 730000China China National Climate Center Beijing 100081China Qilian Shan Station of Glaciology and Ecologic Environment Cold and Arid Regions Environmental and Engineering Research InstituteChinese Academy of SciencesGansu 730000China

Black carbon （BC） concentration and meteorological data are measured discontinuously from May 2009 to March 2011,at the Qilian Shan Station of Glaciology and Ecologic Environment （hereafter ＂QSSGEE＂）,located near the terminal of the Laohugou No.12 Glacier in northwestern Qilian Shan,China.We measured the daily,monthly and seasonal variations of BC concentration in the atmosphere and discussed the possible emission sources.Black carbon background concentration in this region varied in the range of 18–72 ng/m 3 with the highest in summer and the lowest in autumn.The relations between BC concentration and surface wind direction indicated that BC concentration was higher when northwest wind prevails while lower when southeast wind prevails.Air masses backward trajectories showed the potential emission sources in the northwest.Significant positive correlations between daily mean BC concentration and relative humidity indicated that BC might be one of important cloud condensation nuclei.This hypothesis needs to be confirmed further through cloud microphysical features in this region.

关键词： black carbon Qilian Shan cloud condensation nuclei

Simulation of buoyancy-induced turbulent flow from a hot horizontal jet

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Journal of Hydrodynamics 2014年第1期26卷 104-113页

作者： El-AMIN M.F. sun shuyu SALAM Amgad Computational Transport Phenomena Laboratory (CTPL) Division of Physical Sciences and EngineeringKing Abdullah University of Science and Technology

Experimental visualizations and numerical simulations of a horizontal hot water jet entering cold water into a rectangular storage tank are described. Three different temperature differences and their corresponding Reynolds numbers are considered. Both experimental visualization and numerical computations are carried out for the same flow and thermal conditions. The realizable k-e model is used for modeling the turbulent flow while the buoyancy is modeled using the Boussinesq approximation. Polynomial approximations of the water properties are used to compare with the Boussinesq approximation. Numerical solutions are obtained for unsteady flow while pressure, velocity, temperature and turbulence distributions inside the water tank as well as the Froude number are analyzed. The experimental visualizations are performed at intervals of five seconds for all different cases. The simulated results are compared with the visualized results, and both of them show the stratification phenomena and buoyancy force effects due to temperature difference and density variation. After certain times, depending on the case condition, the flow tends to reach a steady state.

关键词： turbulent flow realizablc k - e turbulence model heat transfer jet heat storage

Numerical simulation and analysis of confined turbulent buoyant jet with variable source

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Journal of Hydrodynamics 2015年第6期27卷 955-968页

作者： EL-AMIN Mohamed F. AL-GHAMDI Abdulmajeed SALAMA Amgad sun shuyu Mathematics Department Faculty of ScienceAswan University Computational Transport Phenomena Laboratory(CTPL) Division of Physical Sciences and Engineering(PSE)King Abdullah University of Science and Technology(KAUST) College of Engineering and Islamic Architecture Umm Al-Qura University

In this work, experimental and numerical investigations are undertaken for confined buoyant turbulent jet with varying inlet temperatures. Results of the experimental work and numerical simulations for the problem under consideration are presented. Four cases of different variable inlet temperatures and different flow rates are considered. The realizable k-ε turbulence model is used to model the turbulent flow. Comparisons show good agreements between simulated and measured results. The average devia- tion of the simulated temperature by realizable k-ε turbulent model and the measured temperature is within 2%. The results indicate that temperatures along the vertical axis vary, generally, in nonlinear fashion as opposed to the approximately linear varia- tion that was observed for the constant inlet temperature that was done in a previous work. Furthermore, thermal stratification exits, particularly closer to the entrance region. Further away from the entrance region the variation in temperatures becomes relatively smaller. The stratification is observed since the start of the experiment and continues during the whole course. Numerical experime- nts for constant, monotone increasing and monotone decreasing of inlet temperature are done to show its effect on the buoyancy force in terms of Richardson number.

关键词： realizable k-ε model turbulent jet stratification heat stores CFD

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机器噪声平均声压级计算方法差异性实证研究

电动工具 2024年第1期 19-22页

作者：高淑瑜孙平熙陈奎陈灵通金佩薇陈于林李银松叶宇晨温岭市方圆检测有限公司浙江温岭317525 浙江和超电机有限公司浙江温岭317523

针对家用电器、电动工具、电弧焊机、容积式压缩机、水泵、风机等机器的噪声平均声压级计算过程,介绍典型的机器噪声平均声压级计算方法。分析多种计算方法的差异,同时给出确定噪声平均声压级推荐采用的计算方法。

关键词：电动工具家用电器噪声声压级计算方法

48份水稻骨干材料香味及Badh2变异类型的鉴定

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种子 2024年第1期43卷 107-113页

作者：张倩倩殷春渊刘贺梅胡秀明孟利红王和乐张金霞田芳慧袁泽科孙建权王书玉新乡市农业科学院河南新乡453002 获嘉县亢村镇政府河南新乡453822 河南省驻马店农业学校河南驻马店463001

为促进香稻育种,明确水稻重要种质资源中香味基因的存在情况,本研究将传统香味鉴定方法(KOH浸泡法)与分子标记技术相结合,对48份水稻骨干材料的香味及香味基因Badh2变异类型进行鉴定。结果表明,在48份供试材料中,利用KOH浸泡法检测到具... 详细信息

为促进香稻育种,明确水稻重要种质资源中香味基因的存在情况,本研究将传统香味鉴定方法(KOH浸泡法)与分子标记技术相结合,对48份水稻骨干材料的香味及香味基因Badh2变异类型进行鉴定。结果表明,在48份供试材料中,利用KOH浸泡法检测到具有香味的材料有44份;利用香味基因Badh2的7种等位基因变异类型功能标记检测到含有香味的材料有43份,其中,有41份为纯合香型,2份为杂合型,等位基因Badh2-E2的变异类型有37份,等位基因Badh2-E7的变异类型有6份,未检测到等位基因Badh2-E4-5、Badh2-E12、Badh2-E13、Badh2-UTR和Badh2-Pro的变异类型。通过比较KOH浸泡法与分子标记技术,发现仅有1份材料检测结果不同,明水香稻(X23)用KOH浸泡法检测出具有香味,但本研究所用的Badh2的7种等位基因变异类型功能标记却未检测出含有香味,说明该材料可能属于Badh2其他已报道的或新的等位基因变异类型,也可能是含有新的香味基因。

关键词：水稻香味 Badh2 变异类型

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依据主成分和协整性的大坝变形奇异诊断

振动．测试与诊断 2022年第5期42卷 918-924,1034页

作者：杨光李姝昱孙锦华北水利水电大学水利学院郑州450046 河海大学水文水资源与水利工程科学国家重点实验室南京210098 黄河水利科学研究院郑州450003 华北水利水电大学测绘与地理信息学院郑州450046

针对常规方法对大坝变形原位监测数据中奇异成分的诊断效率较低问题,综合应用主成分分析(principal component analysis,简称PCA)和协整分析(co-integration analysis,简称CA),提出一种新方法。首先,基于PCA,构建平方预测误差(squared p... 详细信息

针对常规方法对大坝变形原位监测数据中奇异成分的诊断效率较低问题,综合应用主成分分析(principal component analysis,简称PCA)和协整分析(co-integration analysis,简称CA),提出一种新方法。首先,基于PCA,构建平方预测误差(squared prediction error,简称SPE)统计量,结合假设检验,提出奇异成分辨识准则;其次,依据CA,运用拓展的迪基-福勒(augmented Dickey-Fuller,简称ADF)检验和逐步回归法,建立奇异成分似然估计模型;最后,通过工程实例分析,检验方法的有效性。结果表明:PCA、拉依达、狄克松和t准则分别可辨识出相对误差为3.81%,7.61%,7.61%和5.08%的孤立型奇异;CA模型对斑点型奇异的估计精度最高,其次是统计模型,自回归模型最差,复相关系数分别为0.9945,0.8715和0.7432。与常规方法相比,PCA-CA方法性能有较大提升,可为大坝变形奇异诊断提供有效的途径。

关键词：大坝变形原位监测奇异诊断主成分协整性

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财务报告问询函对业绩预告质量治理效应研究

东北大学学报（社会科学版） 2023年第3期25卷 16-27页

作者：孙世敏关舒予东北大学工商管理学院辽宁沈阳110169 融通地产(辽宁)有限责任公司财务金融部辽宁沈阳110004

以沪深证券交易所和上市公司为博弈双方构建不完全信息静态博弈模型,通过均衡分析揭示财务报告问询函对业绩预告质量治理效应,并以2015—2019年沪深A股上市公司为研究样本进行实证检验。研究发现:财务报告问询函改善了前瞻性和后视性业... 详细信息

以沪深证券交易所和上市公司为博弈双方构建不完全信息静态博弈模型,通过均衡分析揭示财务报告问询函对业绩预告质量治理效应,并以2015—2019年沪深A股上市公司为研究样本进行实证检验。研究发现:财务报告问询函改善了前瞻性和后视性业绩预告质量,表明财务报告问询函对双重业绩预告质量具有真实治理效应;深圳证券交易所财务报告问询函对双重业绩预告质量的治理效应更显著;财务报告问询函治理效应在公司收函后第二年依然显著,但在收函后第三年不复存在,表明财务报告问询函对业绩预告质量的治理效应具有短暂性。

关键词：财务报告问询函业绩预告质量前瞻性业绩预告后视性业绩预告