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journal of Materials Science & Technology 2013年第4期29卷 367-372页

作者： M jafarzadegan A.Abdollah-zadeh A.H.Feng T.Saeid j.shen H.Assadi Department of Materials Eng. Tarbiat Modares UniversityP.O.Box 14115-143TehranIran School of Materials Science and Eng. Harbin Institute of TechnologyP.O.Box 150001HarbinChina Advanced Materials Research Center Sahand University of TechnologyP.O.Box 51335-1996TabrizIran

Dissimilar fusion welding of austenitic stainless steels to carbon steels has some metallurgical and technical problems. It was suggested that the solid-state nature of friction stir welding （FSW） can overcome these problems and produce a sound weld with reliable mechanical properties. In this study, plates of 304 stainless steel and st37 steel were welded together by FSW at tool rotational speed of 600 r/rain and welding speed of 50 ram/rain. In the stir zone （SZ） of 304 stainless steel, the results showed a refined grain structure with some features of metadynamic recrystallization. In the SZ of st37 steel, the hot deformation of material in the austenite region produced small austenite grains. These grains transformed to fine ferrite and pearlite by cooling the material after FSW. The production of fine grains increased the hardness and tensile strength in the SZ of both sides with respect to their base metals （BMs）.

关键词： Friction stir welding Microstructure Mechanical properties Stainless steel Low carbon steel

Improving weld formability by a novel dual-rotation bobbin tool friction stir welding

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journal of Materials Science & Technology 2018年第1期34卷 135-139页

作者： F.F.Wang W.Y.Li j.shen Q.Wen j.F.dos Santos State Key Laboratory of Solidification Processing Shaanxi Key Laboratory of Friction Welding Technologies Northwestern Polytechnical University Helmholtz-Zentrum Geesthacht Institute of Materials Research Materials Mechanics China Academy of Launch Vehicle Technology Beijing Institute of Astronautical Systems Engineering

A novel dual-rotation bobbin tool friction stir welding （DBT-FSW） was developed, in which the upper shoulder （US） and lower shoulder （LS） have different rotational speeds. This process was tried to weld 3.2 mm thick alunlinum-lithium alloy sheets. The metallographic analysis and torque measurement were carried out to characterize the weld formabiliW. Experimental results show that compared to conven- tional bobbin tool friction stir welding, the DBT-FSW has an excellent process stability, and can produce the defect-free joints in a wider range of welding parameters. These can be attributed to the significant improvement of material flow caused by the formation of a staggered layer structure and the unbalanced force between the US and LS during the DBT-FSW process.

关键词： Bobbin tool friction stir welding Dual rotation Material flow Microstructure Microhardness

Low-Cycle Fatigue Properties of Nickel-Based Superalloys Processed by High-Gradient Directional Solidification

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Acta Metallurgica Sinica(English Letters) 2017年第9期30卷 878-886页

作者： Z.D.Fan D.Wang C.Liu G.Zhang j.shen L.H.Lou j.Zhang Superalloys Division Institute of Metal ResearchChineseAcademy of SciencesShenyang 110016China shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Xi'an Thermal Power Research Institute Co. Ltd.Xi'an 710054China

The low-cycle fatigue （LCF） properties of DD10 （single-crystal） and DZ53 （columnar-grained） superalloys solidified by liquid-metal cooling （LMC） and high-rate solidification （HRS） processes have been systematically investi- gated. It was found that the LCF life of DZ53 solidified by LMC was obviously better than that solidified by HRS. In contrast, for DD10, LMC showed no remarkable influences on LCF properties at high temperature and only improved LCF properties at intermediate temperature. Microstructure examination showed that the cracks generally initiated at microp- ores in the subsurface at intermediate temperature. However, the cracks occurred on the surface due to oxidation, or persistent slip bands near script-MC at high temperature. Therefore, the benefits of LMC technique can be attributed to both of the reduced casting defects which significantly affect the LCF properties at intermediate temperature and the improved microstructural homogeneity which was strongly correlated to the LCF properties of alloys at high temperature.

关键词： Superalloys Rapid solidification Low-cycle fatigue Microstructure

Composition and size dependent torsion fracture of metallic glasses

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journal of Materials Science & Technology 2021年第23期82卷 153-160页

作者： j.Dong j.shen Y.H.Sun H.B.Ke B.A.Sun W.H.Wang H.Y.Bai Institute of Physics Chinese Academy of SciencesBeijing100190PR China College of Materials Science and Opto Electronic Technology University of Chinese Academy of SciencesBeijing100049PR China Songshan Lake Materials Laboratory DongguanGuangdong523808PR China

The fracture of metallic glasses(MGs)of different compositions and sizes down to micrometers under torsion loading were systematically *** to the flat shear fracture along the circumferential plane as commonly supposed under torsion,we find that the torsion fracture of metallic glasses can deviate from flat shear plane,and the fracture angle is closely dependent on the composition and the size of MG *** a conversion method,we show that the torsion fracture of both millimeterand micrometer-sized MGs can be described by the ellipse fracture criterion as originally proposed for the tension *** deviation from the circumferential shear plane under torsion is further shown to intrinsically relate to the fracture toughness of *** tougher MG tends to have a smaller fracture angle with respect to the maximum shear plane,and vice versa,indicating a correlation between the fracture toughness and pressure/normal stress sensitivity in *** results provide new insights on the fracture mechanism and are helpful to design and control the deformation and fracture behavior of MGs under torsion loading.

关键词： Metallic glasses Torsion fracture Pressure sensitivity Fracture toughness

Force-based and displacement-based reliability assessment approaches for highway bridges under multiple hazard actions

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journal of Traffic and Transportation Engineering(English Edition) 2015年第4期2卷 223-232页

作者： Chao Huang jerry j.shen Mi Zhou George C.Lee Department of Civil Structural and Environmental Engineering University at Buffalo Genex Systems/TFHRC 6300 Georgetown Pike Mc Lean 22101 USA National Engineering and Research Center for Highways in Mountain Area Key Laboratory for Old Bridge Detection and Reinforcement Technology of Ministry of Transportation Chang'an University

The strength limit state of American Association of State Highway and Transportation Officials （AASHTO） Load and Resistance Factor Design （LRFD） Bridge Design Spec/fications is developed based on the failure probabilities of the combination of non-extreme loads. The proposed design limit state equation （DLSE） has been fully calibrated for dead load and live load by using the reliability-based approach. On the other hand, most of DLSEs in other limit states, including the extreme events i and li, have not been developed and calibrated though taking certain probability-based concepts into account. This paper presents an assessment procedure of highway bridge reliabilities under the limit state of extreme event i, i. e,, the combination of dead load, live load and earthquake load. A force-based approach and a displacement-based approach are proposed and implemented on a set of nine simplL^ed bridge models. Results show that the displacement-based approach comes up with more convergent and accurate reliabilities for selected models, which can be applied to other hazards.

关键词： BridgeReliability assessmentMultiple hazardsLoadResistance

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未来战争的那些“终结者” 008

电脑报

作者： j.shen

上世纪90年代，阿诺德·施瓦辛格主演的《终结者》三部曲风靡全球，掀起一阵机器人战警的狂潮。20年之后，不仅是机器人战警，机器人军队都已经开始走入现实世界——智能化军事机器人正在成为新的技术发展趋势，而在这方面，美国无疑...

上世纪90年代，阿诺德·施瓦辛格主演的《终结者》三部曲风靡全球，掀起一阵机器人战警的狂潮。20年之后，不仅是机器人战警，机器人军队都已经开始走入现实世界——智能化军事机器人正在成为新的技术发展趋势，而在这方面，美国无疑是走在最前面的。　　8月，本报驻美特约

关键词：

来源： cnki报纸评论

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一位母亲的请求

科学新闻 2022年第4期24卷 63-64页

作者： Megan j.shen 倪伟波韦尔·康奈尔医学院

“请不要醒来。”当我在位于纽约的小公寓里登录另一场Zoom视频会议时，我默默地乞求10个月大的儿子。我使用虚拟背景——一张我大学办公室的照片——来掩盖我在厨房的事实，这样更容易避开大声喊“妈妈”的3岁女儿，以及襁褓中儿子饥...

“请不要醒来。”当我在位于纽约的小公寓里登录另一场Zoom视频会议时，我默默地乞求10个月大的儿子。我使用虚拟背景——一张我大学办公室的照片——来掩盖我在厨房的事实，这样更容易避开大声喊“妈妈”的3岁女儿，以及襁褓中儿子饥饿的哭声。这种会议是新冠肺炎大流行时期的副产品，它增加了我作为一名职场母亲的压力，试图掩盖我为人父母的混乱生活现实。

关键词：

基于胸部CT对部分实性肺结节的影像组学特征诊断侵袭性肺腺癌:一项多中心研究

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国际医学放射学杂志 2021年第1期44卷 108-109页

作者： G.Wu H.C.Woodruff j.shen T.Refaee S.Sanduleanu A.Ibrahim 赵泽豫

摘要CT部分实性结节(PSN)的实性成分是浸润性腺癌的反映,但是缺乏PSN和结节周围组织的影像组学特征的研究。目的研究并验证PSN诊断浸润性肺腺癌的影像组学特

关键词：

震前蠕变滑移的地震预报意义：来自纳/微米尺度地质构造证据

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世界地震译丛 2020年第1期51卷 54-62页

作者： H.T.Chao Z.C.Wang L.Wang Y.Sun j.shen 王雷(译) 王志才(校) 不详山东省地震局

对采自郯庐活动断裂带及其分支活动断裂的最新断层泥样品,在纳/微米尺度下进行观察,发现发震断层在黏滑滑移之前,普遍存在蠕变滑移现象。表现为黏土片状矿物的褶皱、绕砾滑动、“流水状”排列、撕裂等变形形式。这种蠕变滑移对应于岩石... 详细信息

对采自郯庐活动断裂带及其分支活动断裂的最新断层泥样品,在纳/微米尺度下进行观察,发现发震断层在黏滑滑移之前,普遍存在蠕变滑移现象。表现为黏土片状矿物的褶皱、绕砾滑动、“流水状”排列、撕裂等变形形式。这种蠕变滑移对应于岩石在应力作用下进入屈服阶段尤其是亚失稳阶段的韧性变形。由于这一变形阶段改变了物质结构,故在震源区附近会引起诸多地震前兆物理量变化。鉴于黏滑滑移即将发生,因此这一阶段是捕捉地震前兆的最佳时机,也许是最后的机会。我们认为,发震断层的震前蠕变滑移具有地震预报意义。

关键词：发震断层蠕变滑移黏滑滑移纳/微米尺度构造地震预报

慢性乙型肝炎病毒携带者肝纤维化及脾硬度定量弹力成像:剪切波及瞬时弹力成像与肝活检的相关性

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国际医学放射学杂志 2014年第1期 81-82页

作者： V.Y.Leung j.shen V.W.Wong j.Abrigo G.L.Wong A.M.Chim 谷磊磊 Institute of Digestive Disease Prince of Wales HospitalThe Chinese University of Hong KongNgan Shing StreetShatinHong KongSARChina 852

目的探讨剪切波(SW)弹性成像评价慢性乙型肝炎病毒携带者肝纤维化的可行性,及与瞬时弹力成像所见比较。方法本研究得到伦理委员会同意,并签署知情同意书。

关键词：慢性乙型肝炎病毒肝纤维化肝疾病携带者弹性成像弹力肝活检剪切波相关性