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Initial corrosion behavior and mechanism of 7B04 aluminum alloy under acid immersion and salt spray environments

Chinese Journal of Aeronautics 2022年第1期35卷 277-289页

作者： Yangguang ZHANG yueliang chen Yong ZHANG Guixue BIAN chenguang WANG Andong WANG Naval Aviation University Qingdao Campus Qingdao 266041China

The initial corrosion behavior and mechanism of 7B04 aluminum alloy under acid immersion and salt spray environments(pH=3.5)are studied by Scanning Electron Microscope(SEM),optical microscope,Fourier Transform Infrared Spectroscopy(FT-IR),X-Ray Diffraction(XRD),potentiodynamic polarization,Electrochemical Impedance Spectroscopy(EIS),and Scanning Kelvin Probe(SKP).The results show that pitting corrosion occurs at the initial corrosion stage,and the potential difference between the second phase particles is the main cause of pitting.Pitting pits on different locations gradually expand and coalesce with the proceeding of corrosion.The main components of corrosion products are Al_(2)O_(3),Al(OH)_(3),and AlCl_(3),and the generation rate of the corrosion product layer under the salt spray environment is larger than that under acid immersion environment.Under both environments,the Volta potential distribution first disperses and then concentrates,while the charge transfer resistance first decreases and then increases with the corrosion time.The Volta potential gradually shifts in a positive direction,indicating that corrosion products have an inhibitory effect on corrosion.After the same corrosion time,the corrosion product layer resistance and the expectation of the Volta potential of the salt spray sample are higher than those of the immersion sample.Comparatively,the corrosion current density for the salt spray sample is significantly lower than the immersion sample,which indicates that the thicker the corrosion product layer,the stronger the inhibition of corrosion reaction.

关键词： 7B04 aluminum alloy Acid salt spray Corrosion mechanism Corrosion products Electrochemistry Scanning Kelvin probe

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Assimilation of Sea Surface Temperature in a Global Hybrid Coordinate Ocean Model

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Advances in Atmospheric Sciences 2018年第10期35卷 1291-1304页

作者： yueliang chen Changxiang YAN Jiang ZHU International Center for Climate and Environment Sciences Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China University of Chinese Academy of Sciences Beijing 100049China State Key Laboratory of Acoustics Institute of AcousticsChinese Academy of SciencesBeijing 100190China

The Hybrid Coordinate Ocean Model(HYCOM) uses different vertical coordinate choices in different regions. In HYCOM, the prognostic variables include not only the seawater temperature, salinity and current fields, but also the layer thickness. All prognostic variables are usually adjusted in the assimilation when multivariate data assimilation methods are used to assimilate sea surface temperature(SST). This paper investigates the effects of SST assimilation in a global HYCOM model using the Ensemble Optimal Interpolation multivariate assimilation method. Three assimilation experiments are conducted from 2006–08. In the first experiment, all model variables are adjusted during the assimilation process. In the other two experiments, the temperature alone is adjusted in the entire water column and in the mixed layer. For comparison, a control experiment without assimilation is also conducted. The three assimilation experiments yield notable SST improvements over the results of the control experiment. Additionally, the experiments in which all variables are adjusted and the temperature alone in all model layers is adjusted, produce significant negative effects on the subsurface temperature. Also, they yield negative effects on the subsurface salinity because it is associated with temperature and layer thickness. The experiment adjusting the temperature alone in the mixed layer yields positive effects and outperforms the other experiments. The heat content in the upper 300 m and 300–700 m layers further suggests that it yields the best performance among the experiments.

关键词： ensemble optimal interpolation multivariate data assimilation sea surface temperature ocean heat content

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Availability modeling for periodically inspection system with different lifetime and repair-time distribution

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Chinese Journal of Aeronautics 2019年第7期32卷 1667-1672页

作者： Junliang LI yueliang chen Yong ZHANG Hailiang HUANG Qingdao Campus Naval Aviation UniversityQingdao266041China The92635th Unit of Navy Qingdao266041China

Availability is a main feature of design and operation of all engineering system. Recently,availability evaluation of periodical inspection systems with different structures is at the center of attention due to the wide application in engineering. In this paper, an analytical and probabilistic availability model for periodical inspection system is proposed by a new recursively algorithm,which can achieve limiting average availability and instantaneous availability of periodical inspection system under arbitrary lifetime and repair-time distributions. Then three application examples are presented, the systems lifetime and repair-time are respectively fellow exponential/exponential,Weibull/normal and Weibull/lognormal distribution. Finally, a Weibull/lognormal system is studied to analyze the dynamic relationship between inspection period and availability. The results indicate that the proposed approach can provide the technology support for improving system availability and determining reasonable inspection period.

关键词： Availability Inspection period Lifetime distribution Reliability Repair-time distribution

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优秀男子短距离速度滑冰运动员起跑技术的运动学特征及训练启示

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中国体育科技 2024年第3期60卷 14-22页

作者：房英杰王子朴严力陈月亮母毅刚孙辉哈尔滨体育学院黑龙江哈尔滨150008 首都体育学院北京100191 厦门医学院福建厦门361023 沈阳体育学院辽宁沈阳110102 北京开放大学北京100081

目的:起跑是决定短距离速度滑冰运动成绩的关键技术,基于AI三维动作捕捉系统探究该项目起跑技术的运动学特征。方法:以国内8名高水平男子短距离速度滑冰运动员为测试对象,测试起跑预备姿势、起动和疾跑前6步的时间、空间、角度和速度参... 详细信息

目的:起跑是决定短距离速度滑冰运动成绩的关键技术,基于AI三维动作捕捉系统探究该项目起跑技术的运动学特征。方法:以国内8名高水平男子短距离速度滑冰运动员为测试对象,测试起跑预备姿势、起动和疾跑前6步的时间、空间、角度和速度参数。结果:1)时间参数中起动时是决定起跑实效性的核心指标(r=0.951),反应时和单步时间次之;2)空间位置参数中起动结束后的步幅、疾跑第2步和第4步的步幅与步宽以及疾跑第5步和第6步的身体重心高度与起跑实效性表现出高负相关(r>|0.5|),HCOM/H表现出起动过程略有降低,疾跑第1步迅速升高而后趋于平稳;3)空间角速参数中后稳定角、起动和疾跑初期蹬冰角、躯干角与起跑实效性表现出高正相关(r>0.5),膝角的蹬伸幅度在93°~148°变化;4)起动和疾跑前4步的速度与起跑实效性表现出高负相关(r>|0.5|),速度达到6.79 m/s时出现从滑跑向滑行技术转化过渡点。结论:起跑表现出“单侧发力、多向运动、非稳定支撑”的动作模式特征,疾跑第5~6步是从滑跑向滑行技术的过渡期。启示:陆冰结合训练中加强快速反应能力与动作速度训练,静力性力量、快速力量与爆发力训练,平衡与稳定控制能力训练,最佳动作协同模式训练以及下肢肌肉韧带刚性训练,有助于提升起跑运动表现。

关键词：速度滑冰起跑运动学特征

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乙烯焦油综合利用现状及未来发展趋势

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当代化工研究 2024年第2期 8-10页

作者：吴晓辉林京尹勇勇陈月亮严文荣王佳兵中建安装集团有限公司江苏210046

乙烯焦油是一种烃类裂解副产物资源,具有很高的循环利用潜力。传统上,乙烯焦油往往被视为废弃物,被焚烧或填埋处理,导致资源的浪费和环境的污染。而通过综合利用乙烯焦油,可将其中的有机成分提取出来,用于生产各种化工产品、能源和材料... 详细信息

乙烯焦油是一种烃类裂解副产物资源,具有很高的循环利用潜力。传统上,乙烯焦油往往被视为废弃物,被焚烧或填埋处理,导致资源的浪费和环境的污染。而通过综合利用乙烯焦油,可将其中的有机成分提取出来,用于生产各种化工产品、能源和材料,这样的循环利用模式有助于实现资源的有效利用和环境的可持续发展。尤其是乙烯焦油作为原料,成本低且易得,因此在未来具有很好的应用前景。

关键词：乙烯焦油循环利用现状发展前景

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MiR-30a-5p alleviates LPS-induced HPMEC injury through regulation of autophagy via Beclin-1

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BIOCELL 2024年第3期48卷 431-441页

作者： RAN PAN JIAYAN MAO yueliang ZHENG WEI chen JUNPING GUO LIJUN WANG Rainbowfish Rehabilitation and Nursing School Hangzhou Vocational&Technical CollegeHangzhou310018China Cancer Institute of Integrated Traditional Chinese and Western Medicine Key Laboratory of Cancer Prevention and Therapy Combining Traditional Chinese and Western MedicineZhejiang Academy of Traditional Chinese MedicineHangzhou310012China Geriatric Medicine Center Department of EndocrinologyZhejiang Provincial People’s Hospital(Affiliated People’s Hospital)Hangzhou Medical CollegeHangzhou310015China

Background:Sepsis,a type of systemic disease,can impact nearly all organs,tissues and cells.Among them,endothelial cells are amongst theﬁrst to be affected and respond to the insult.In this study,we investigated the protective effects of microRNA-30a-5p(miR-30a-5p)on human pulmonary microvascular endothelial cells(HPMECs)treated with lipolysaccharide(LPS).Methods:An in vitro model of sepsis was established in HPMECs with the use of LPS.Transfecting with different tools(mimetic and inhibitor)to modify miR-30a-5p expression.Cell viability,proliferation and apoptosis were detected by the CCK-8 assay,the EdU kit andﬂuorescence staining,respectively.The autophagy-related protein and mRNA expression,the number of autophagosomes were separately examined through Western blot analysis,qPT-PCR and confocal microscopy.TargetScan and the luciferase reporter assays were used to probe target genes interacting with miR-30a-5p.Results:LPS caused a reduction in the viability and proliferation of HPMECs,as well as an elevation in the number of apoptotic cells.Subsequently,we observed that miR-30a-5p might play a role in preventing LPS-induced inhibition of cell damage and decreasing HPMEC apoptosis,suggesting the potential function of miR-30a-5p in this injury process.Finally,we conﬁrmed that miR-30a-5p exerts its protective effect by regulating cell autophagy,possibly by targeting Beclin-1.Conclusion:Our study provided evidence that autophagy is a crucial aspect in the protective role of miR-30a-5p against LPS-induced HPMEC injury,identifying a promising target for sepsis-related endothelial cell injury.

关键词： Sepsis Endothelial cells MicroRNA Systemic inflammatory response syndrome

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Numerical Analysis on the Static Performance of Gas Journal Bearing by Using Finite Element Method

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Nanomanufacturing and Metrology 2024年第1期7卷 28-47页

作者： Pengfeng Wang Yuntang Li Xiang Gao yueliang Ye Ruirui Li Xiaolu Li Yuan chen Jie Jin Cong Zhang College of Modern Science and Technology China Jiliang UniversityJinhua 322002China College of Mechanical and Electrical Engineering China Jiliang UniversityHangzhou 310018China

In this paper,finite element method is used to calculate the static performance of gas journal bearing,in which rotation speed term is introduced into the stiffness matrix of linear triangular element to realize the performance calculation of the bearing with rotation speed.The results indicate that the average gas film thicknesses corresponding to the maximum load capac-ity and stiffness,and the minimum attitude angle increase with the growth of orifice diameter.Load capacity and stiffness significantly improved with the increase of rotation speed,eccentricity ratio and supply pressure when the bearing has thin average gas film thickness.Attitude angle increases with the growth of rotation speed,while the growth rate slows down or even decreases at high speed.The most effective way of reducing attitude angle is to increase supply pressure.It can be found that rotation speed affects attitude angle through changing gas pressure difference between two orifices,while other parameters have the same effect by changing gas pressure at orifice outlet.

关键词： Finite element method(FEM) Gas journal bearing Stiffness matrix Attitude angle

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Availability modelling for periodically inspected systems under mixed maintenance policies

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Journal of Systems Engineering and Electronics 2021年第3期32卷 722-730页

作者： LI Junliang chen yueliang ZHANG Yong ZHANG Zhuzhu FAN Weijie Qingdao Campus Naval Aeronautics UniversityQingdao 266041China

The availability of a periodic inspection system under mixed maintenance policies is studied in this paper.To accommodate the characteristic of multiple failure modes for complex systems,the system failures can be divided into two failure modes:hard failure and soft failure.When hard failure occurs,the corresponding corrective maintenance will be performed,taking a random time under the perfect maintenance policy;in contrast,if the soft failure is found,the corresponding preventive maintenance will be performed,taking a random time under the imperfect maintenance policy.The dynamic age setback model is adopted for imperfect maintenance,which can accurately reflect the fault characteristics of the degraded system.Then an analytical model for system steady state availability and instantaneous availability are derived.Moreover,the optimal method to maximize the system steady-state availability through adjusting the inspection interval is researched.According to the above research,the optimization of system unit time cost,preventive maintenance intervals and availability is researched.Finally,the developed approach is demonstrated by a numerical example.

关键词： availability reliability maintenance repairable system maintenance policy

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含裂纹螺接件应力强度因子三维有限元分析

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机械工程学报 2011年第20期47卷 121-126页

作者：郁大照陈跃良海军航空工程学院飞行器工程系烟台264001 海军航空工程学院青岛分院青岛266041

对飞机结构螺接件来说,最主要的强度问题之一,是在疲劳载荷下会产生裂纹并扩展。而目前对含裂纹螺接件的应力强度因子(Stress intensity factor,SIF)分析多以简化的二维有限元模型为主。为此,在考虑螺栓与孔壁间的非线性接触、摩擦和螺... 详细信息

对飞机结构螺接件来说,最主要的强度问题之一,是在疲劳载荷下会产生裂纹并扩展。而目前对含裂纹螺接件的应力强度因子(Stress intensity factor,SIF)分析多以简化的二维有限元模型为主。为此,在考虑螺栓与孔壁间的非线性接触、摩擦和螺栓预紧力等因素影响的基础上,利用非线性有限元软件MSC.Marc构建含裂纹螺接件的三维有限元分析模型,通过分析得到不同损伤模式下的SIF与裂纹长度沿板厚度方向的变化曲线。结果表明,虽然螺接件孔边裂纹是复合型裂纹,但Ⅰ型SIF起主导作用,Ⅱ型和Ⅲ型SIF可忽略不计;在裂纹长度一定时,接触面处的SIF最大,外表面处最小,孔边双侧裂纹对称时的SIF大于孔边单侧裂纹情形;裂纹长度相同时,含沉孔螺接件接触面上的SIF大于直孔情形时相应的SIF,而外表面的SIF趋势则恰恰相反。

关键词：螺接件应力强度因子多裂纹有限元法

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枕垫应力对飞机搭接件完整性的影响研究

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机械工程学报 2012年第12期48卷 37-42页

作者：郁大照陈跃良海军航空工程学院飞行器工程系烟台264001 海军航空工程学院青岛分院青岛266041

根据腐蚀产物化学特性和板壳理论,建立搭接件接触面腐蚀厚度与枕垫应力定量关系的数学模型。在此基础上,利用非线性有限元软件MSC.Marc分析枕垫应力对搭接结构完整性的影响。分析时考虑螺栓与孔壁间的非线性接触、摩擦、干涉配合、材料... 详细信息

根据腐蚀产物化学特性和板壳理论,建立搭接件接触面腐蚀厚度与枕垫应力定量关系的数学模型。在此基础上,利用非线性有限元软件MSC.Marc分析枕垫应力对搭接结构完整性的影响。分析时考虑螺栓与孔壁间的非线性接触、摩擦、干涉配合、材料损失、枕垫应力及几何非线性等因素影响。模拟结果表明,搭接件的最大应力点位置随腐蚀水平的增加而变化,腐蚀初期和腐蚀量大于4%时,搭接件应力对枕垫应力比较敏感。随着腐蚀程度的加重,内表面裂尖应力强度因子随之增大,而外表面裂尖应力强度因子随之减小。另外,分析腐蚀对搭接件的影响时,只考虑蒙皮厚度的变化,而不考虑枕垫应力得出的结果是保守和危险的。计算结果和结论可作为该类结构损伤容限设计的参考依据。

关键词：搭接件枕垫应力有限元法结构完整性

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