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Investigation of tribological characteristics of nickel alloybased solid-lubricating composites at elevated temperatures under vacuum

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Friction 2021年第5期9卷 990-1001页

作者： Jinming ZHEN Jun CHENG Hui TAN qichun sun Shengyu ZHU Jun YANG Weimin LIU College of Materials Science and Engineering Liaocheng UniversityLiaocheng 252059China State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China

The development of a high‐performance solid‐lubricating composite with excellent self‐lubricity over a broad temperature range in vacuum is significant to solve the frictional problems of spatial *** this study,the vacuum tribological behaviors of nickel‐matrix/Ag/(Ca,Ba)F2/graphite(0–2 wt%)composites were studied from 25 to 800°*** results show that the synergistic effects of solid lubricants can significantly improve the tribological properties of the composites in vacuum,with the graphite content contributing *** 2 wt%graphite,a low friction coefficient(0.14–0.25)and the lowest wear rate((0.12–4.78)×10^(-5) mm^(3)∙N^(-1)∙m^(-1))were observed in vacuum over the entire testing temperature ***,the wear mechanisms were clarified via analysis of the chemical composition and morphologies of the sliding surfaces.

关键词： metal matrix composite graphite solid lubrication vacuum high temperature

A(CrFeNi)_(83)(AlTi)_(17) high-entropy alloy matrix solid-lubricating composite with exceptional tribological properties over a wide temperature range

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Journal of Materials Science & Technology 2023年第22期153卷 75-91页

作者： Yushan Geng Jun Cheng Hui Tan qichun sun Juanjuan Chen Shengyu Zhu Anh Kiet Tieu Jun Yang Weimin Liu State Key Laboratory of Solid Lubrication Chinese Academy of SciencesLanzhou Institute of Chemical PhysicsLanzhou 730000China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Shandong Laboratory of Yantai Advanced Materials and Green Manufacturing Yantai 264000China School of Mechanical MaterialsMechatronic and Biomedical EngineeringUniversity of WollongongWollongongNSW 2500Australia

High-entropy alloy matrix solid-lubricating composites(HSLCs)are promising anti-wear and friction-reduced materials to meet the demands of complicated engineering *** we present a strat-egy to develop HSLCs by using the coupled high-entropy phases of(BCC+FCC+L2_(1))with near-equal volume fraction as the matrix material,instead of using the usual single phase-dominated high-entropy phases,which can preserve the intrinsic strength and deformability of the matrix while activating adap-tive wear protection during *** enables a low coefficient of frictions of 0.23-0.31 and wear rates within the order of 10^(-6)-10^(-5) mm^(3) N m^(-1) for the(CrFeNi)_(83)(AlTi)_(17)-Ag-BaF_(2)/CaF_(2) HSLC between room-temperature and 800℃,considerably outperforming the reported HSLCs and conventional alloy matrix solid-lubricating *** low and moderate temperatures,the synergistic Ag-BaF_(2)/CaF_(2) lubricat-ing films eliminate the surface stress concentration upon wear,thus suppressing three-body abrasion and surface roughening during the groove multiplication *** elevated temperatures,the high-entropy composite tribo-layers provide the friction interface with strong and deformable stress shielding,which avoids the oxidative and adhesive wear triggered by the delamination of the *** sim-ilar coupled high-entropy matrix phases may open an avenue for further optimization of the tribological properties of the HSLCs.

关键词： Solid-lubricating composites High-entropy alloys Wear mechanism High temperature Tribochemical reaction

Study on the Driveability During Engine Start Process for A P2 Hybrid Vehicle

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汽车技术 2017年第9期 26-33页

作者： Wang Junhua sun qichun Cao Jian Tongji University Shanghai 201804 China FAW Corporation Limited R&D Center Changchun 130011

Perfect performance of economy and emissions make hybrid powertrain used more widely, but frequent engine start may affect vehicle's driveability. In order to obtain how to improve hybrid vehicle's driveability, Audi A6 Hybrid which is equipped with a P2 powertrain with two engine start modes: conventional start with a 12 V starter and hybrid start with a high-voltage motor, is evaluated under several driving situations with frequently-used criteria. Test results show Audi A6 Hybrid can gain perfect driveability in all engine start situations. Avoiding to start engine frequently in some special situations, suitable choice of engine start modes, compensating driver's request torque by down-shifting gear or increasing the traction motor torque, and maneuver sequences of K0 clutch are all helpful to obtain perfect driveability for Audi A6 Hybrid.

关键词：汽车混合动力系统发展现状技术创新

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DE算法优化CNN的滚动轴承故障诊断研究

噪声与振动控制 2022年第4期42卷 165-171,176页

作者：孙祺淳李媛媛上海工程技术大学电子电气工程学院上海201620

针对卷积神经网络(Convolutional Neural Network,CNN)在滚动轴承故障诊断应用中所存在超参数难以确定、网络输出不稳定等问题,提出一种基于差分进化算法(Differential Evolution,DE)优化卷积神经网络的故障诊断模型(CNN-DE)。首先,该... 详细信息

针对卷积神经网络(Convolutional Neural Network,CNN)在滚动轴承故障诊断应用中所存在超参数难以确定、网络输出不稳定等问题,提出一种基于差分进化算法(Differential Evolution,DE)优化卷积神经网络的故障诊断模型(CNN-DE)。首先,该故障诊断模型利用DE算法来自适应调节CNN中的超参数,同时将CNN的诊断精度和稳定性一起作为DE算法优化的目标,使得CNN在保证精度的同时降低网络的波动;其次,使用自适应噪声完备集合经验模态分解(Complete Ensemble Empirical Mode Decomposition with Adaptive Noise,CEEMDAN)结合多参数的诊断方法,从原始信号中提取出更加有效的故障特征;最后,根据提取出的特征采用CNN-DE、CNN和BP等算法进行故障诊断,结果表明所提出的算法模型拥有更高的精度和更稳定的性能,也具有优异的抗噪能力,显示了CNN-DE在故障诊断应用中的可靠性。

关键词：故障诊断卷积神经网络差分进化算法自适应噪声完备集合经验模态分解滚动轴承

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英语语法中的“时”与“体”之辩

科教导刊 2015年第7Z期 104-105页

作者：孙启春郑州澍青医学高等专科学校河南郑州450064

在英语语法里,时(tense)和体(aspect)是用来表达时间的范畴。时和体把事件和时间联系起来。当说话人把把事件和参照时间联系起来的时候,这就是"时"。然而一个事件往往有起始,发展和结束等阶段。这个事件是起始,是持续进行,还是完成,这是... 详细信息

在英语语法里,时(tense)和体(aspect)是用来表达时间的范畴。时和体把事件和时间联系起来。当说话人把把事件和参照时间联系起来的时候,这就是"时"。然而一个事件往往有起始,发展和结束等阶段。这个事件是起始,是持续进行,还是完成,这是"体"。体反映了事件发展的状态。时体范畴密切相关,时是体的基础,没有时就没有体。二者的差异是人类的认知力在感知物质世界时视角的转变的结果。时,体反映了人类思维的丰富性和深刻性。

关键词：时体认知视角

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探究英语词汇学习

辽宁省交通高等专科学校学报 2018年第4期20卷 73-75页

作者：孙启春郑州澍青医学高等专科学校河南郑州450064

词汇量是衡量语言学习者的重要标尺。有效扩大词汇量需要学习者具有端着的学习态度,遵循记忆的规律,把词汇学习和句法篇章阅读相结合,并掌握一套有效的学习方法。语言学习总是发生在特点的社会环境之中。它是社会环境、学习者心智特点... 详细信息

词汇量是衡量语言学习者的重要标尺。有效扩大词汇量需要学习者具有端着的学习态度,遵循记忆的规律,把词汇学习和句法篇章阅读相结合,并掌握一套有效的学习方法。语言学习总是发生在特点的社会环境之中。它是社会环境、学习者心智特点、物资条件(内容、目标、环节等),学习过程(策略、技巧和思维运作)、成果评价五个部分。一个语言学习者如果能充分发挥各个要素的优势,他的学习就会获得最大限度的收获。

关键词：词汇量记忆力探究

热氧化改性TC4合金在液体润滑条件下的摩擦学行为研究

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摩擦学学报 2017年第4期37卷 487-494页

作者：孙奇春胡天昌樊恒中徐仰涛张永胜胡丽天中国科学院兰州学物理研究所固体润滑国家重点实验室甘肃兰州730000 中国科学院大学北京100049 兰州理工大学甘肃省有色金属新材料省部共建国家重点实验室甘肃兰州730050

应用热氧化表面处理技术,在TC4表面制备了金红石型的TiO_2氧化膜.考察了热氧化改性TC4合金分别在去离子水和PAO10润滑条件下的摩擦学特性,并通过磨损表面分析讨论了其在不同条件下的减摩抗磨机理.结果表明:经过热氧化改性的TC4合金,无论... 详细信息

应用热氧化表面处理技术,在TC4表面制备了金红石型的TiO_2氧化膜.考察了热氧化改性TC4合金分别在去离子水和PAO10润滑条件下的摩擦学特性,并通过磨损表面分析讨论了其在不同条件下的减摩抗磨机理.结果表明:经过热氧化改性的TC4合金,无论在PAO10润滑条件还是去离子水润滑条件下,都表现出优异的摩擦学性能.相较于未处理的TC4表面,改性TC4合金在PAO10和去离子水润滑条件下磨损率分别下降了99%(50 N,5 cm/s)和98%(10 N,9 cm/s).

关键词：钛合金热氧化液体润滑摩擦学行为

某插电式混合动力汽车动力系统的模式切换过程分析

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汽车安全与节能学报 2018年第1期9卷 79-84页

作者：孙起春王军华郭洪江赵永强同济大学上海201804 中国第一汽车集团有限公司技术中心长春130011

为掌握串并联构型混合动力汽车(HEV)动力系统模式切换的控制方法,对某款插电式混合动力汽车动力系统的各模式间动态切换的协调控制过程进行了理论分析,并在常温环境仓和转鼓试验室对车辆开展典型工况的测试试验,从测试结果验证各模式间... 详细信息

为掌握串并联构型混合动力汽车(HEV)动力系统模式切换的控制方法,对某款插电式混合动力汽车动力系统的各模式间动态切换的协调控制过程进行了理论分析,并在常温环境仓和转鼓试验室对车辆开展典型工况的测试试验,从测试结果验证各模式间切换过程的控制策略理论分析的正确性。研究结果表明:该车辆动力系统的各模式之间切换过程均归结为发动机起停机过程控制和扭矩转移过程控制,通过2个电机的协同配合,有效地完成扭矩的转移分配,实现了各模式间的动态切换,且测试结果与理论分析的控制过程基本一致。

关键词：混合动力汽车(HEV) 串并联构型模式切换协调控制对标分析

Coupling of sulfur and boron in carbonaceous material to strengthen persulfate activation for antibiotic degradation:Active sites,mechanism,and toxicity assessment

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Chinese Chemical Letters 2023年第5期34卷 292-301页

作者： Feng Ye Wei sun Kangfeng Pang Wenchao Yang Mengjie Pu qichun Zhang Research Center for Eco-environmental Engineering Dongguan University of TechnologyDongguan 523830China Guangling College and School of Horticulture and Plant Protection Yangzhou UniversityYangzhou 225009China College of Life and Environmental Science Wenzhou UniversityWenzhou 325035China Center of Super-Diamond and Advanced Films(COSDAF) City University of HongkongHong KongChina

Carbon-mediated persulfate advanced oxidation processes(PS-AOPs)are appealing in contaminant *** the first time,S,B-co-doped carbon-based persulfate activators were synthesized through direct carbonization of sodium lignosulfonate and boric *** degrading sulfamethoxazole(SMX),CSB-750 obtained 98.7%removal and 81.4%mineralization within 30 *** comparison with solo S or B doping,S and B co-doped carbon showed the coupling effect for enhanced *** rate constant(kobs)of 0.1679 min^(-1)was 22.38-and 279.83-fold higher than those of CS-750(0.0075 min^(-1))and CB-750(0.0006 min^(-1)),*** degradation was efficient at strong acidic and weak basic conditions(pH 3-9).Substantial inhibition effect was presented at strong basic condition(pH 10.95)and in presence of CO_(3)^(2-).The CO_(3)^(2-)-caused inhibition was the combined result of the cooperation of pH and quenching O_(2)^(·-).Thiophene sulfur,BC_(3),BC_(2)O,and structural defects were identified as the active sites for PS *** and nonradical pathways were both involved in the CSB-750/PS/SMX system,where^(1)O_(2)dominated the degradation,SO_(4)^(·-),·OH and direct electron transfer played the subordinate role,and O_(2)^(·-)served as a precursor for the formation of partial^(1)O_(2).The toxicity of degradation system,the effect of real water matrix,and the reusability of carbocatalysts were comprehensively *** possible degradation pathways were *** work focuses on the catalytic performance improvement through the coupling effect of S,B co-doping,and develops an advanced heteroatom doping system to fabricate carbonaceous persulfate activators.

关键词： S B-co-doped carbons Advanced oxidation process Nonradical pathway Coupling effect