铝型材挤压在线淬火系统喷嘴流速的仿真优化
作者：
刘志文;李落星;胡理中;王冠
期刊：
哈尔滨工业大学学报 ,2019年51(1):191-200 ISSN：0367-6234
通讯作者：
Li, Luoxing(llxly2000@163.com)
作者机构：
[刘志文] School of Mechanical Engineering, University of South China, Hengyang;Hunan;421001, China;[李落星; 胡理中; 王冠] State Key Laboratory of Advanced Design and Manufacture for Vehicle Body (Hunan University), Changsha;410082, China
通讯机构：
[Li, L.] S;State Key Laboratory of Advanced Design and Manufacture for Vehicle Body (Hunan University), Changsha, China
关键词：
铝型材;在线淬火;界面换热系数;喷嘴流速;数值仿真;残余变形
摘要：
为制定最优的在线淬火系统喷嘴流速方案,基于Fluent和Workbench软件平台建立了π字形大断面铝型材挤压在线淬火过程的有限元模型.为了准确确定仿真模型中的热边界条件,采用末端淬火实验和反热传导相结合的方法,获得了不同喷水流量下的界面换热系数.系统分析了3种不同喷嘴流速方案铝型材实际挤压在线淬火冷却过程中的流速场、温度场、应力场和残余变形.结果表明:随着喷水流量的增大,淬火介质与型材的界面换热系数增加且到达峰值的时刻越晚.有限元模拟的特征点温度与试验测量的温度变化趋势一致,相对误差范围为-1.1%～7.8%,验证了所建立的淬火有限元模型是准确的.初始方案一型材挤压在线淬火过程中各部位冷却不均匀,在接头处产生较大的热应力,使型材上端面发生内凹. 3种不同的喷嘴流速方案中,方案三中型材表面和中间截面位置淬火冷却过程能得到更为均匀的温度场,残余应力和变形最小.研究方法和结果可为复杂铝合金型材挤压在线淬火系统喷嘴流速的制定和优化提供理论指导.
语种：
中文
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熔盐堆用镍基合金在熔融氟盐中的腐蚀研究进展
作者：
朱红梅;李柏春;朱锦云;邱长军;唐忠锋
期刊：
材料导报 ,2019年33(11):1813-1820 ISSN：1005-023X
通讯作者：
Qiu, Changjun(qiuchangjun106@126.com)
作者机构：
[朱红梅; 李柏春; 朱锦云; 邱长军] School of Mechanical Engineering, University of South China, Hengyang;421001, China;[唐忠锋] Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai;201800, China;[朱红梅; 李柏春; 朱锦云; 邱长军] 421001, China
关键词：
镍基合金;熔融氟盐;腐蚀;影响因素;改善途径
摘要：
熔盐堆(Molten salt reactor,MSR)是第四代先进核反应堆中唯一的液态燃料反应堆,因在热转化效率、中子经济性、固有安全性、在线燃料循环、核废料处理等方面具有无可比拟的优势而备受国内外研究者的关注。熔盐的选择对MSR 的运行安全及效率至关重要。熔融氟化盐如 LiF-BeF_2(FLiBe)、LiF-NaF-KF(FLiNaK)等具有较小的热中子吸收截面、高热导率、高比热容、良好的流动性、低的蒸气压(高温时)、良好的高温稳定性等一系列优异的热物化性能,被公认为MSR 最理想的冷却剂和核燃料载体。目前,国内外均选用镍基合金作为MSR 的主要结构材料。然而,超强高温腐蚀性熔融氟盐的存在对镍基合金提出了苛刻的要求。目前,国内外学者们对熔盐堆用镍基合金在熔融氟盐中腐蚀行为的研究主要集中在两个方面:一是镍基合金在熔融氟盐中热腐蚀行为的影响因素及微观机制,二是提高镍基合金的耐高温熔盐腐蚀性能。一般认为,镍基合金在熔融氟盐中的腐蚀机制主要包括以下四种:本质腐蚀、氧化性杂质引起的腐蚀、温差驱动的腐蚀和异种材料引起的腐蚀。因此,合金自身和熔盐腐蚀环境是影响镍基合金在氟盐中热腐蚀行为的两大主要因素。在合金自身方面,主要为合金元素(Ni、Cr、Mo、Fe、Si 等)及含量、合金显微组织(晶界特征、组织缺陷等)的影响;在熔盐腐蚀环境方面,主要为熔盐组分、熔盐中的杂质及腐蚀产物、熔盐温度、坩埚材质、核裂变产物等的影响。目前,提高镍基合金耐熔盐腐蚀性能的主要途径有:在镍基合金方面,包括有微合金化(添加Ti、RE 等)、晶界工程处理、陶瓷相增强复合材料技术;在熔盐方面,包括熔盐纯化、添加单质金属(如Zr、Be、Li 等)降低熔盐的氧化还原势等。此外,采用电镀法、激光熔覆法、化学气相沉积法、等离子喷涂法等表面改性技术在镍基合金上制备金属涂层(Ni、Co、Mo、NiCoCrAlY 等)和陶瓷涂层(氮化物如AlN、碳化物如SiC)。本文重点综述了镍基合金在熔融氟盐中热腐蚀行为的主要影响因素及微观机制,以及国内外研究者在提高镍基合金耐高温熔盐腐蚀性能方面的研究进展。针对当前已开发的镍基合金与强腐蚀性的熔融氟盐相容性亟待解决的一些关键基础问题,提出了未来镍基合金在熔融氟盐工程应用中的主要技术方向和发展趋势,为耐高温氟盐腐蚀材料的研究和开发提供重要思路。
语种：
中文
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An uncertain optimization method based on interval differential evolution and adaptive subinterval decomposition analysis
作者：
Fu Chunming* ;Cao Lixiong
期刊：
Advances in Engineering Software ,2019年134:1-9 ISSN：0965-9978
通讯作者：
Fu Chunming
作者机构：
[Fu Chunming] Univ South China, Coll Mech Engn, Hengyang 421001, Peoples R China.;[Fu Chunming] Cooperat Innovat Ctr Nucl Fuel Cycle Technol & Eq, Hengyang 421001, Peoples R China.;[Cao Lixiong] Hunan Univ, State Key Lab Adv Design & Mfg Vehicle Body, Changsha 410082, Hunan, Peoples R China.
通讯机构：
[Fu Chunming] U;Univ South China, Coll Mech Engn, Hengyang 421001, Peoples R China.
关键词：
Differential evolution;Interval optimization;Interval possibility;Subinterval analysis;Uncertainty
摘要：
An interval differential evolution (IDE)with adaptive subinterval decomposition analysis is suggested to directly solve the nonlinear uncertain optimization problems with interval parameters. The adaptive subinterval decomposition analysis technique is proposed to calculate the upper and lower bounds of objective function and constraints caused by interval uncertainties. An adaptive convergence mechanism is utilized to ensure the accuracy of achieved bounds. Moreover, within the framework of IDE, the interval possibility model is employed to deal with the interval constraints of uncertain optimization problems and the interval preferential rule is used to select the promising solutions to retain into the next evolutionary population. Both numerical and engineering examples are eventually given to demonstrate the validity of the proposed method. © 2019 Elsevier Ltd
语种：
英文
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掺杂低含量SiO_2对激光熔覆CaP 生物陶瓷涂层性能的影响
作者：
刘均环;朱卫华;朱红梅;施佳鑫;管旺旺;...
期刊：
红外与激光工程 ,2019年48(6):0606007 ISSN：1007-2276
通讯作者：
Wang, Xinlin(wxl_ly000@aliyun.com)
作者机构：
南华大学机械工程学院,湖南衡阳,421001;南华大学电气工程学院,湖南衡阳421001;超快微纳技术与激光先进制造湖南省重点实验室,湖南衡阳421001;南华大学机械工程学院,湖南衡阳421001;南华大学电气工程学院,湖南衡阳,421001
通讯机构：
[Wang, X.] S;School of Mechanical Engineering, University of South China, Hengyang, China
关键词：
激光熔覆;TC4钛合金;SiO2-HA涂层;耐腐蚀性能;生物活性
摘要：
为提高医用TC4钛合金表面熔覆羟基磷灰石(HA)涂层的植入稳定性和生物活性, 采用激光熔覆方法制备出不同含硅量的CaP生物陶瓷涂层。利用扫描电子显微镜(SEM)和X射线衍射仪(XRD)表征了熔覆层组织形貌和物相组成。结果表明: 添加SiO2(1wt.%、3wt.%)后形成Ca2SiO4相, 熔覆层中部组织细化。通过电化学腐蚀和体外SBF浸泡实验研究了SiO2含量对涂层耐腐蚀性和生物活性的影响。电化学腐蚀结果表明: 随着SiO2含量的增大, 涂层表面腐蚀电流密度逐渐减小; 体外SBF浸泡结果表明: 添加SiO2可以加快涂层表面类骨磷灰石的形成, 其中, 添加SiO2为1wt.%时涂层表面类骨磷灰石呈均匀分布。因此, 低含量SiO2可以提高生物陶瓷涂层的耐腐蚀性和生物活性。
语种：
中文
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热弹耦合条件下的齿廓修形设计
作者：
罗彪;李威
期刊：
哈尔滨工程大学学报 ,2018年39(6):1059-1065 ISSN：1006-7043
通讯作者：
Li, Wei(liwei@me.ustb.edu.cn)
作者机构：
[罗彪; 李威] School of Mechanical Engineering, Beijing University of Science and Technology, Beijing, 100083, China;[罗彪] School of Mechanical Engineering, University of South China, Hengyang, 421001, China
通讯机构：
[Li, W.] S;School of Mechanical Engineering, Beijing University of Science and Technology, Beijing, China
关键词：
齿轮;热弹耦合;齿廓修形;载荷分配系数;传动误差
摘要：
为研究热变形对齿轮传动特性的影响,本文推导出了渐开线齿廓上任一点沿啮合线方向的热变形量计算公式,并在此基础上研究了热变形对齿间载荷分配系数、传动误差及齿廓修形的影响.提出了热弹耦合条件下齿廓分段修形和连续修形两种方式,并得到两种方式下修形量的表达式;分析了按两种不同方式进行修形后的载荷分配系数和传动误差.研究结果表明:分段修形可以很好地保持啮合过程载荷分配系数的连续性,消除载荷突变,减小传动误差的波动,使绝对误差趋于恒定;连续修形载荷分配系数连续,载荷突变消失,单齿啮合区稍有增大,误差波动较分段修形增大.本研究可以有效降低齿轮传动过程中的振动噪声,具有一定的应用价值.
语种：
中文
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Research on the preparation and shielding properties of W–Ni–Fe alloy material by liquid phase sintering
作者：
Tang Dewen* ;Zou Shuliang;Yan Liang
期刊：
Powder Metallurgy ,2018年61(1):28-35 ISSN：0032-5899
通讯作者：
Tang Dewen
作者机构：
[Tang Dewen; Yan Liang] Univ South China, Sch Mech Engn, Hengyang 421001, Peoples R China.;[Zou Shuliang; Tang Dewen] Univ South China, Hunan Prov Key Lab Emergency Safety Technol & Equ, Hengyang, Peoples R China.
通讯机构：
[Tang Dewen] U;Univ South China, Sch Mech Engn, Hengyang 421001, Peoples R China.
关键词：
W–Ni–Fe series alloy;liquid phase sintering;mechanical properties;microstructure;shielding effect
摘要：
Traditional and single shielding material has not satisfied the demand for radiation protection. Shielding materials with a good comprehensive performance have attracted attention. W–Ni–Fe alloys with different Ni/Fe ratios have been prepared through liquid phase sintering using W, Ni and Fe elementary powders. The microstructure, morphology and fracture appearance of such prepared W–Ni–Fe alloys with different Ni/Fe ratios were analysed with the SEM and metallographic test. The effects of the Ni/Fe ratio on the density, microhardness, tensile strength and shielding efficiency were investigated. The results show that for W–Ni–Fe alloys with different Ni/Fe ratios, the alloy surfaces are composed of ellipsoidal W particles on a Ni–Fe substrate. However, when the Ni/Fe ratio is 7:3, uniform and spherical W crystals are embedded in the Ni–Fe substrate and evidently form dense boundaries, which contribute to the good mechanical properties and shielding effect of the alloy.<br/> ©2017 Institute of Materials, Minerals and Mining Published by Taylor & Francis on behalf of the Institute.
语种：
英文
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Ultra-precision finishing of optical mold by magnetorheological polishing using a cylindrical permanent magnet
作者：
Wang, Yongqiang* ;Yin, Shaohui;Hu, Tian
期刊：
International Journal of Advanced Manufacturing Technology ,2018年97(9-12):3583-3594 ISSN：0268-3768
通讯作者：
Wang, Yongqiang
作者机构：
[Wang, Yongqiang] Univ South China, Sch Mech Engn, Hengyang 421001, Hunan, Peoples R China.;[Yin, Shaohui] Hunan Univ, Natl Engn Res Ctr High Efficiency Grinding, Changsha 410082, Hunan, Peoples R China.;[Hu, Tian] Changsha Nanometer Ultra Precis Mfg Technol Ltd C, Changsha 430100, Hunan, Peoples R China.
通讯机构：
[Wang, Yongqiang] U;Univ South China, Sch Mech Engn, Hengyang 421001, Hunan, Peoples R China.
关键词：
Magnetorhelogical polishing;Optical mold;Spatial frequency error;Removal;Roughness;Form accuracy
摘要：
A magnetorheological polishing was proposed to be used for optical glass mold finishing, aiming at suppressing middle spatial frequency errors from ultra-precision grinding while improving surface roughness. A small polishing head, with a cylindrical permanent magnet enveloped by a nonmagnetic outer shell, was also developed. Polishing experiments were performed on concave aspheric tungsten carbide molds. The results demonstrated the developed magnetorheological polishing successfully suppressed the middle spatial frequency errors on the optical mold by decreasing amplitude to 1 nm, while improving overall surface finish to 1 nm in R<inf>a</inf>.<br/> ©2018, Springer-Verlag London Ltd., part of Springer Nature.
语种：
英文
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Effect of negative bias on TiAlSiN coating deposited on nitrided Zircaloy-4
作者：
Zhou Jun* ;Feng Zhendong;Fan Xiangfang* ;Liu Yanhong;Li Huanlin
期刊：
Journal of Nuclear Materials ,2018年498:76-82 ISSN：0022-3115
通讯作者：
Zhou Jun;Fan Xiangfang
作者机构：
[Feng Zhendong; Fan Xiangfang; Zhou Jun; Fan, XF] Univ South China, Sch Mech Engn, Hengyang 421001, Peoples R China.;[Li Huanlin; Liu Yanhong] Cent Res Inst, Natl Elect Investment Grp, Beijing 102209, Peoples R China.
通讯机构：
[Zhou, J; Fan, XF] U;Univ South China, Sch Mech Engn, Hengyang 421001, Peoples R China.
关键词：
TiAlSiN coating;Zircaloy-4;Negative bias;High temperature oxidation behavior;Surface morphology;Adhesion strength
摘要：
TiAlSiN coatings were deposited on the nitrided Zircaloy-4 by multi-arc ion plating at -100 V, -200 V and -300 V. In this study, the high temperature oxidation behavior of coatings was tested by a box-type resistance furnace in air for 3 h at 800 degrees C; the macro-morphology of coatings was observed and analyzed by a zoom-stereo microscope; the micro-morphology of coatings was analyzed by a scanning electron microscopy (SEM), and the chemical elements of samples were analyzed by an energy dispersive spectroscopy(EDS); the adhesion strength of the coating to the substrate was measured by an automatic scratch tester; and the phases of coatings were analyzed by an X-ray diffractometer(XRD). Results show that the coating deposited at -100 V shows better high temperature oxidation resistance behavior, at the same time, Al elements contained in the coating is of the highest amount, meanwhile, the adhesion strength of the coating to the substrate is the highest, which is 33N. As the bias increases, high temperature oxidation resistance behavior of the coating weakens first and then increases, the amount of large particles on the surface of the coating increases first and then decreases whereas the density of the coating decreases first and then increases, and adhesion strength of the coating to the substrate increases first and then weakens. The coating's quality is relatively poor when the bias is -200 V. (C) 2017 Published by Elsevier B.V.
语种：
英文
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Effect of roughness of substrate and sputtering power on the properties of TiN coatings deposited by magnetron sputtering for ATF
作者：
Xiao, Weiwei* ;Deng, Hua* ;Zou, Shuliang;Ren, Yuhong;Tang, Dewen;...
期刊：
Journal of Nuclear Materials ,2018年509:542-549 ISSN：0022-3115
通讯作者：
Xiao, Weiwei;Deng, Hua
作者机构：
[Xiao, Changfei; Xiao, Weiwei; Zou, Shuliang; Tang, Dewen] Univ South China, Sch Mech Engn, Hengyang 421001, Hunan, Peoples R China.;[Ren, Yuhong; Deng, Hua; Zhou, Xi; Lei, Ming; Xiao, Weiwei; Chen, Yao] CNNC Jianzhong Nucl Fuel Co, Yibin 644000, Sichuan, Peoples R China.
通讯机构：
[Xiao, Weiwei] U;[Deng, Hua] C;Univ South China, Sch Mech Engn, Hengyang 421001, Hunan, Peoples R China.;CNNC Jianzhong Nucl Fuel Co, Yibin 644000, Sichuan, Peoples R China.
关键词：
Accident-tolerant fuel;Adhesion strength;Roughness of substrate;Sputtered TiN coating;Sputtering power
摘要：
TiN coatings have been deposited on Zr-4 substrates using direct current (DC) magnetron sputtering and the effects of roughness of substrate and sputtering power on the microstructure, thickness/deposition rate, adhesion properties and residual stress of coatings have been studied. The microstructures of the coatings were characterized by using scanning electron microscope (SEM) and X-ray diffractometer (XRD). The thicknesses of the coatings were detected by using SEM. The adhesion property was tested by using scratch testing. The residual stress was measured by using the XRD method. The results shown that the microstructure, thickness/deposition rate, adhesion properties and residual stress of coating are significantly influenced by the roughness of substrate and sputtering power. The roughness of substrate has significant influence on the surface micrograph of the coating but not obvious on the thickness/deposition rate. The microstructure, thickness/deposition rate is remarkably affected by the sputtering power. In addition, the adhesion property does not vary monotonically with the roughness of substrate and the sputtering power. The adhesion strength presents a trend of first rises and then declines with the increase of surface roughness of substrate and sputtering power. The residual stresses of the coating were compressive and the residual stress magnitude of the coatings deposited by relatively low sputtering power was higher than that deposited by relatively high sputtering power. (C) 2018 Elsevier B.V. All rights reserved.
语种：
英文
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激光原位合成Al_2O_3-TiO_2复合陶瓷涂层组织结构与性能
作者：
张曼莉;邱长军;蒋艳林;郑文权;夏琰
期刊：
材料工程 ,2018年46(2):57-65 ISSN：1001-4381
通讯作者：
Qiu, Chang-Jun(qiuchangjun@hotmail.com)
作者机构：
[张曼莉; 邱长军; 蒋艳林; 郑文权; 夏琰] School of Mechanical Engineering, University of South China, Hengyang;Hunan;421001, China;[张曼莉; 邱长军; 蒋艳林; 郑文权; 夏琰] Hunan;[张曼莉; 邱长军; 蒋艳林; 郑文权; 夏琰] 421001, China
通讯机构：
[Qiu, C.-J.] S;School of Mechanical Engineering, University of South China, Hengyang, Hunan, China
关键词：
火焰喷涂;激光原位合成技术;Al_2O_3-TiO_2复合陶瓷涂层;微观组织结构;性能
摘要：
先利用火焰喷涂技术在中国低活化马氏体钢表面制备了CrFeAlTi涂层,然后通过激光原位反应技术在火焰喷涂涂层表面原位合成了Al_2O_3-TiO_2复合陶瓷涂层。分别采用体视显微镜、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线衍射仪(XRD)、显微硬度计、立式万能摩擦磨损试验机以及静态铅铋腐蚀实验装置等分析测试手段对涂层的形貌、微观组织结构、物相组成、显微硬度、干滑动摩擦磨损性能以及耐液态铅铋合金腐蚀性能等进行了研究。实验结果表明:激光原位合成的Al_2O_3-TiO_2复合陶瓷涂层表面整体平整、光滑、致密,基本没有凹坑、裂纹和孔隙等缺陷,与基体之间形成了良好的冶金结合。涂层内部存在完全结晶区和非结晶区,且界面明显。涂层表面主要物相为Al_2O_3, TiO_2,(Al.948Cr.052)_2O_3,Fe_2TiO_5和FeCr等。涂层截面平均显微硬度约为1864.2HV0.2,比基体CLAM钢提高了约3倍,且沿横截面方向呈平稳过渡的阶梯状分布。与基体CLAM钢相比,涂层具有良好的耐磨性能,其磨损量仅为基体的1/6,并且涂层在液态铅铋中表现出良好的耐腐蚀性能。
语种：
中文
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钛合金表面激光熔覆制备低含硅量生物陶瓷涂层
作者：
孙楚光;刘均环;陈志勇;朱卫华;朱红梅;...
期刊：
红外与激光工程 ,2018年47(3):0306003-1-0306003-7 ISSN：1007-2276
通讯作者：
Wang, Xinlin(wxl_ly000@aliyun.com)
作者机构：
[孙楚光; 刘均环; 朱红梅; 何彬; 王新林] School of Mechanical Engineering, University of South China, Hengyang;421001, China;[陈志勇; 朱卫华] School of Electrical Engineering, University of South China, Hengyang;[孙楚光; 刘均环; 陈志勇; 朱卫华; 朱红梅; 何彬; 王新林] 421001, China;[王新林] 421001, China<&wdkj&>School of Electrical Engineering, University of South China, Hengyang
通讯机构：
[Wang, X.] S;School of Mechanical Engineering, University of South China, Hengyang, China
关键词：
激光熔覆;TC4钛合金;含硅生物陶瓷涂层;生物活性;耐腐蚀性能
摘要：
采用5 kW横流CO_2激光器对表面预涂覆HA和SiO_2混合粉末的TC4钛合金激光熔覆获得低含硅量生物陶瓷涂层。利用X射线衍射仪(XRD)、扫描电镜(SEM)、X射线能谱仪(EDS)分析熔覆层的显微组织与物相成分,通过模拟体液(SBF)浸泡实验初步探讨涂层的生物活性,并通过电化学腐蚀中的动电位扫描实验研究涂层在SBF中的腐蚀行为。实验结果表明,低含硅量生物陶瓷涂层与基体呈冶金结合,在SBF中熔覆层的腐蚀电位与基材相比提高了84.4 mV,腐蚀电流密度下降了约6倍,在SBF中浸泡7天后熔覆层表面沉积了大量的类骨磷灰石,熔覆层表现出良好的耐腐蚀性和生物相容性。
语种：
中文
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Optimal design of heating system in rapid thermal cycling blow mold by a two-step method based on sequential quadratic programming
作者：
Xiao, Cheng-Long* ;Huang, Han-Xiong
期刊：
International Communications in Heat and Mass Transfer ,2018年96:114-121 ISSN：0735-1933
通讯作者：
Xiao, Cheng-Long
作者机构：
[Xiao, Cheng-Long] Univ South China, Dept Mech Engn, Hengyang 421001, Peoples R China.;[Huang, Han-Xiong] South China Univ Technol, Lab Micro Molding & Polymer Rheol, Guangzhou 510640, Guangdong, Peoples R China.
通讯机构：
[Xiao, Cheng-Long] U;Univ South China, Dept Mech Engn, Hengyang 421001, Peoples R China.
关键词：
Automotive spoiler;Extrusion blow molding;Optimal design;Rapid thermal cycling molding;Sequential quadratic programming
摘要：
The blow molded parts made of engineering resins usually possess poor surface quality, and thus cannot satisfy the requirement of high-gloss appearance in some applications. For this reason, a rapid thermal cycling extrusion blow molding (RTCEBM) technology was developed, the process principle was presented and its process procedure optimization was also analyzed. Aiming at obtaining uniform temperature distribution on both mold cavity and core surfaces, a two-step optimization method based on sequential quadratic programming (SQP) algorithm was proposed for designing the heating system in RTCEBM mold, and its effectiveness was demonstrated by optimizing the electric-heating system for the RTCEBM mold of an automotive spoiler. After optimization, the maximum core surface temperature difference is reduced by 77% from the initial value of 22.06 °C to the optimal value of 5.05 °C; meanwhile, the molding process coordination can also be ensured. This work may provide an effective method to optimize the heating system for these molds with cavity and core sides to be heated simultaneously. © 2018 Elsevier Ltd
语种：
英文
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The Insertion Mechanism of a Living Cell Determined by the Stress Segmentation Effect of the Cell Membrane during the Tip–Cell Interaction
作者：
Fan, Na* ;Jiang, Hai;Ye, Zhiyi;Wu, Guiyong;Kang, Yuejun;...
期刊：
Small ,2018年14(22):e1703868 ISSN：1613-6810
通讯作者：
Fan, Na;Peng, Bei;Wang, Guixue
作者机构：
[Peng, Bei; Wang, Qun; Fan, Na; Fan, N; Peng, B; Jiang, Hai; Wu, Guiyong; Zhang, Guocheng] Univ Elect Sci & Technol China, Sch Mech & Elect Engn, Chengdu 611731, Sichuan, Peoples R China.;[Wang, Guixue; Ye, Zhiyi; Ran, Xiaolin] Chongqing Univ, Key Lab Biorheol Sci & Technol, Minist Educ, Coll Bioengn, Chongqing 400044, Peoples R China.;[Kang, Yuejun] Southwest Univ, Inst Clean Energy & Adv Mat, Chongqing 400715, Peoples R China.;[Guo, Jian] Univ South China, Sch Mech Engn, Hengyang 421001, Hunan, Peoples R China.
通讯机构：
[Fan, N; Peng, B] U;[Wang, Guixue] C;Univ Elect Sci & Technol China, Sch Mech & Elect Engn, Chengdu 611731, Sichuan, Peoples R China.;Chongqing Univ, Key Lab Biorheol Sci & Technol, Minist Educ, Coll Bioengn, Chongqing 400044, Peoples R China.
关键词：
atomic force microscopy;cell membranes;insertion mechanism;stress concentration;stress segmentation
摘要：
Atomic force microscopy probes are proved to be powerful tools to measure and manipulate the individual cell, providing potential applications for the controlled drug/protein delivery. However, the measured insertion efficiency varies dramatically from 20 to 80%, in some cases, the nanotip can never penetrate the cell membrane no matter how much force is applied to it. Thus, the insertion mechanism of a living cell during the tip–cell interaction must be thoroughly investigated before this technology comes into practical applications. In this work, a multistructural cell model is established to study the tip–membrane interaction. The simulation results show that the stress of the cell membrane can be divided into two stages by the stress segmentation point S. After point S, the stress of the cell membrane increases slightly and most of the indentation force is allocated to the cytoskeleton. This phenomenon is called “stress segmentation effect of the cell membrane,” which confirms the hypothesis based on the experimental studies. Moreover, according to the experimental and numerical studies, the hypothesis of the stress segmentation effect also explains the reason that modifying the cell membrane or using the manmade sharpened nanotip can increase the insertion efficiency. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
语种：
英文
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An investigation of the wear on Silicon Surface at High Humidity
作者：
Wang, Xiaodong;Guo, Jian;Xu, Lin;Cheng, Guanggui;Qian, Linmao*
期刊：
Materials ,2018年11(6):1027- ISSN：1996-1944
通讯作者：
Qian, Linmao
作者机构：
[Cheng, Guanggui; Xu, Lin; Wang, Xiaodong] Jiangsu Univ, Ctr Micro Nano Sci & Technol, Zhenjiang 212013, Peoples R China.;[Guo, Jian; Qian, Linmao; Wang, Xiaodong] Southwest Jiaotong Univ, Tribol Res Inst, State Key Lab Tract Power, Chengdu 610031, Sichuan, Peoples R China.;[Guo, Jian] Univ South China, Sch Mech Engn, Hengyang 421000, Peoples R China.
通讯机构：
[Qian, Linmao] S;Southwest Jiaotong Univ, Tribol Res Inst, State Key Lab Tract Power, Chengdu 610031, Sichuan, Peoples R China.
关键词：
monocrystalline silicon;wear;high humidity;etch
摘要：
Using an atomic force microscope (AFM), the wear of monocrystalline silicon (covered by a native oxide layer) at high humidity was investigated. The experimental results indicated that tribochemistry played an important role in the wear of the silicon at different relative humidity levels (RH = 60%, 90%). Since the tribochemical reactions were facilitated at 60% RH, the wear of silicon was serious and the friction force was around 1.58 μN under the given conditions. However, the tribochemical reactions were restrained when the wear pair was conducted at high humidity. As a result, the wear of silicon was very slight and the friction force decreased to 0.85 μN at 90% RH. The slight wear of silicon at high humidity was characterized by etching tests. It was demonstrated that the silicon sample surface was partly damaged and the native oxide layer on silicon sample surface had not been totally removed during the wear process. These results may help us optimize the tribological design of dynamic microelectromechanical systems working in humid conditions.<br/> ©2018 by the authors.
语种：
英文
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High Temperature Oxidation Resistance of Magnetron Sputtering and Multi-arc Ion Plating Cr Films on Zirconium Alloy
作者：
黄鹤;邱长军;陈勇;胡良斌;刘艳红;...
期刊：
中国表面工程 ,2018年31(2):51-58 ISSN：1007-9289
通讯作者：
Qiu, Chang-Jun(qiuchangjum@hotmail.com)
作者机构：
[邱长军; 陈勇; 胡良斌; 黄鹤] School of Mechanical Engineering, University of South China, Hengyang, Hunan, 421001, China;[李怀林; 刘艳红] State Power Investment Corporation Central Research Institute, Beijing, 102209, China
关键词：
磁控溅射;多弧离子镀;Cr 涂层;孔洞;高温抗氧化性能
摘要：
为了研究磁控溅射(MS)和多弧离子镀(MAIP)技术制备Cr涂层的高温抗氧化性能,分别在锆合金表面制备厚度约5 μm的Cr涂层.利用氧化动力学曲线对比研究800 ℃条件下涂层的高温抗氧化性能,利用SEM、XRD、 EDS分析涂层表面形貌和相结构.结果表明:磁控溅射和多弧离子镀Cr涂层均能显著提高锆合金的高温抗氧化性能;磁控溅射Cr涂层表面光滑、致密,但涂层表面存在一定数量的孔洞,占涂层表面积0.40%,氧化7 h后涂层表面出现裂纹,单位面积氧化增重6.434 mg/cm~2;与磁控溅射Cr涂层相比,多弧离子镀Cr涂层不再有(211)单一择优取向,Cr涂层厚度均匀,表面平整,膜/基界面分明,孔洞相对较少,占涂层表面积0.21%,氧化7 h后涂层表面依然致密,单位面积氧化增重5.616 mg/cm~2,高温抗氧化性能优于磁控溅射Cr涂层.
语种：
中文
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A subinterval decomposition analysis method for uncertain structures with large uncertainty parameters
作者：
Fu, C. M.* ;Cao, L. X.;Tang, J. C.;Long, X. Y.
期刊：
Computers & Structures ,2018年197(Feb.):58-69 ISSN：0045-7949
通讯作者：
Fu, C. M.
作者机构：
[Fu, C. M.] Univ South China, Coll Mech Engn, Hengyang 421001, Peoples R China.;[Fu, C. M.; Cao, L. X.; Long, X. Y.; Tang, J. C.] Hunan Univ, Coll Mech & Vehicle Engn, State Key Lab Adv Design & Mfg Vehicle Body, Changsha 410082, Hunan, Peoples R China.
通讯机构：
[Fu, C. M.] U;Univ South China, Coll Mech Engn, Hengyang 421001, Peoples R China.
关键词：
Uncertainty;Interval analysis;Subinterval;Decomposition;Large uncertainty
摘要：
A simple and efficient subinterval decomposition analysis method is proposed to evaluate the lower and upper bounds of structural responses with large uncertain parameters. The proposed method decomposes the original structural system with multi-dimensional interval parameters into multiple one-dimensional subsystems. Every subsystem has only one interval parameter and the other interval parameters are substituted by their midpoint values. By dividing the interval parameter of each subsystem into several subintervals with small uncertainty, the lower and upper bounds of the system are approximately calculated by only a few subinterval combinational analyses instead of all possible combinations of subintervals. Finally, the accuracy and efficiency of the proposed method compared with the first-order Taylor method, Chebyshev interval method and traditional subinterval method are verified by several numerical examples and applications. © 2017 Elsevier Ltd
语种：
英文
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A dimension-reduction interval analysis method for uncertain problems
作者：
Tang, J. C.* ;Fu, C. M.
期刊：
工程与科学中的计算机建模(英文) ,2017年113(3):249-271 ISSN：1526-1492
通讯作者：
Tang, J. C.
作者机构：
[Fu, C. M.; Tang, J. C.] Hunan Univ, Coll Mech & Vehicle Engn, State Key Lab Adv Design & Mfg Vehicle Body, Changsha 410082, Hunan, Peoples R China.;[Fu, C. M.] Univ South China, Coll Mech Engn, Hengyang 421001, Peoples R China.
通讯机构：
[Tang, J. C.] H;Hunan Univ, Coll Mech & Vehicle Engn, State Key Lab Adv Design & Mfg Vehicle Body, Changsha 410082, Hunan, Peoples R China.
关键词：
Dimension-reduction method;Interval analysis;Interval uncertainty;Overestimation.
摘要：
In this paper, an efficient interval analysis method called dimension-reduction interval analysis (DRIA) method is proposed to calculate the bounds of response functions with interval variables, which provides a kind of solution method for uncertainty analysis problems of complex structures and systems. First, multi-dimensional function is transformed into multiple one-dimensional functions by extending dimension reduction method to the interval analysis problem. Second, all the one-dimensional functions are transformed to standard quadratic form by second order Taylor expansion method. As a result, the multi-dimensional function is approximately represented by the functions that each interval variable occurs once, and interval power arithmetic can be used to efficiently calculate the bounds of response functions in restricted overestimation. Finally, three numerical examples and an engineering application are investigated to demonstrate the validity of the proposed method. Copyright © 2017Tech Science Press.
语种：
英文
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基于热弹耦合的齿轮热刚度研究
作者：
罗彪;李威;李林升
期刊：
中南大学学报(自然科学版) ,2017年48(12):3209-3215 ISSN：1672-7207
通讯作者：
Li, Wei(liwei@me.ustb.edu.cn)
作者机构：
[罗彪; 李威] School of Mechanical Engineering, University of Science and Technology Beijing, Beijing, 100083, China;[李林升; 罗彪] School of Mechanical Engineering, University of South China, Hengyang, 421001, China
通讯机构：
School of Mechanical Engineering, University of Science and Technology Beijing, Beijing, China
关键词：
热弹耦合;热刚度;齿轮;有限元法;解析法
摘要：
为研究热对齿轮刚度的影响,引入齿轮热刚度的概念,并定义热刚度的计算方法。引入热应力修正系数Xte,对热应力进行修正,得到热弹耦合应力的计算方法和热弹耦合变形的计算方法。在热弹耦合条件下,分别利用有限元法和解析法计算出齿轮的单齿热刚度和啮合热刚度,2种方法的计算结果基本吻合。研究结果表明:齿轮在热弹耦合作用下的热刚度为齿轮的弹性刚度与修正的热膨胀刚度的串联。齿轮啮合热刚度相对于弹性啮合刚度整体下降,单齿热刚度与弹性刚度沿啮合线的分布曲线在齿根附近存在唯一交点,单齿热刚度在交点的齿根侧大于弹性刚度,在交点的齿顶侧小于弹性刚度。
语种：
中文
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Propagation of in-plane wave in viscoelastic monolayer graphene via nonlocal strain gradient theory
作者：
Xiao, Weiwei* ;Li, Li;Wang, Meng
期刊：
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING ,2017年123(6):1-9 ISSN：0947-8396
通讯作者：
Xiao, Weiwei
作者机构：
[Xiao, Weiwei] Univ South China, Sch Mech Engn, Hengyang 421001, Hunan, Peoples R China.;[Li, Li] Huazhong Univ Sci & Technol, State Key Lab Digital Mfg Equipment & Technol, Sch Mech Sci & Engn, Wuhan 430074, Hubei, Peoples R China.;[Wang, Meng] Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Hunan, Peoples R China.
通讯机构：
[Xiao, Weiwei] U;Univ South China, Sch Mech Engn, Hengyang 421001, Hunan, Peoples R China.
关键词：
Phase Velocity;Graphene Sheet;Nonlocal Parameter;Strain Gradient Theory;Nonlocal Elasticity Theory
摘要：
The behaviors of monolayer graphene sheet have attracted increasing attention of many scientists and researchers. In this study, the propagation behaviors of in-plane wave in viscoelastic monolayer graphene are investigated. The constitutive equation and governing equation for in-plane wave propagation is developed by employing Hamilton’s principle and nonlocal strain gradient theory. By solving the governing equation of motion, the closed-form dispersion relation between phase velocity and wave number is derived and an asymptotic phase velocity can be acquired. The effects of wave number, material length scale parameter, nonlocal parameter and damping coefficient on in-plane wave propagation behaviors are discussed in the numerical studies. It is found that, when exciting wavelengths or structural dimensions become comparable to the material length scale parameters and nonlocal parameters, the scaling effects on wave propagation behaviors are significant. For nanoscaled graphene sheet, the effects of nonlocal parameter, material length scale parameter and damping coefficient on phase velocity are tiny at low wave numbers while significant at high wave numbers. The phase velocity would increase with the increase of material length scale parameter or the decrease of nonlocal parameter and damping coefficient. Furthermore, results indicate that the asymptotic phase velocity can be increase by increasing material length scale parameter or decreasing nonlocal parameter. © 2017, Springer-Verlag Berlin Heidelberg.
语种：
英文
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The Corrosion Behavior of Multiphase Ceramic Protective Coatings on China Low Activation Martensitic Steel Surface in Flowing Liquid Lead-Bismuth Eutectic
作者：
Chen, Yong;Qiu, Changjun* ;Hu, Liangbin;Nong, Yi;Liu, Zan;...
期刊：
steel research international ,2017年88(8):1600413- ISSN：1611-3683
通讯作者：
Qiu, Changjun
作者机构：
[Liu, Zan; He, Bin; Nong, Yi; Chen, Yong; Hu, Liangbin; Qiu, Changjun] Univ South China, Sch Mech Engn, Hengyang 421001, Peoples R China.
通讯机构：
[Qiu, Changjun] U;Univ South China, Sch Mech Engn, Hengyang 421001, Peoples R China.
关键词：
corrosion behavior;laser in-situ reaction;LBE;multiphase Ceramic;protective coatings
摘要：
China low activation martensitic (CLAM) steel is the preferred candidate structural material for the Chinese international thermonuclear experimental reactor test blanket module (ITER TBM). Surface coating technology is often adopted to alter or improve the performance of materials. In CLAM steel, surface treatment plays a key role in rendering them appropriate for application in accelerator driven sub-critical system (ADS). Here, the authors prepare multiphase ceramic coatings on CLAM steel via laser in-situ reaction technology. The prepared multiphase ceramic coatings exhibit optimal corrosion resistance. The liquid lead-bismuth eutectic (LEB) corrosion resistance can be attributed to inferior wettability of interface between the LEB and multiphase ceramic coatings, faint shear force produced by LEB, and stable chemical and physical property of the coatings. Moreover, the irradiated specimens also display excellent corrosion resistance against helium ions irradiation. The CLAM steel is found to suffer significant corrosion in the flowing LEB. Such multiphase ceramic coatings as a protective layer on the ADS candidate structural materials CLAM steel surface exhibit the strongest LEB corrosion resistance, which can be applied to handle nuclear waste under extreme conditions.
语种：
英文
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