Results 21 to 30 of about 18,307 (136)
Rare Metals, Volume 45, Issue 5, May 2026.ABSTRACT The inherent brittleness of hardmetals stems from the rigid covalent bond in the ceramic matrix and the sharp ceramic/metal interface, which restricts the nucleation and motion of dislocations. In this study, a novel strategy is proposed to activate significant dislocation behaviors in the WC matrix by employing a non‐equiatomic CoNiFeCr ...
Cheng Qian +9 more
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Rare Metals, Volume 45, Issue 5, May 2026.ABSTRACT Laser powder bed fusion (LPBF) can fabricate high‐entropy alloys (HEAs) with refined microstructure and enhanced mechanical properties. However, the deformation and fatigue mechanisms of Al‐containing HEAs produced by LPBF remain unclear. In this work, we systematically investigate the tensile properties, deformation mechanisms, and high‐cycle
Dan Zheng +4 more
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International Journal of Applied Linguistics, Volume 35, Issue 3, Page 1121-1133, August 2025.ABSTRACT Although psychological factors such as emotion and engagement have gained increasing attention for their role in language learning success, a substantial gap remains in understanding the sources of boredom and its impact on learners’ engagement, whether behavioural, affective or cognitive, in languages other than English (LOTE).
Xian Zhao, Danping Wang
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Risk, Hazards &Crisis in Public Policy, Volume 15, Issue 3, Page 347-373, September 2024.Abstract This study examines the impact of regulations and standard procedures on safety outcomes in unmanned aerial vehicle (UAV) operations, specifically focussing on Norwegian military UAV systems, from a high‐reliability organization (HRO) perspective. By analyzing data from existing regulations, accident reports, and interviews with military drone
Riana Steen +2 more
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, 1984 前言残余应力对疲劳的影响是长期以来人们十分关注的课题,因为人们逐渐认识到许多疲劳现象都与残余应力相关。例如疲劳裂纹的形成与扩展、少数极高应力、平均应力、加载次序、裂纹迟滞效应、缺口应力集中等都与残余应力有密切关系。残余应力是影响疲劳的一个重要因素。因此,弄清残余应力的大小和分布,以及残余应力与上述疲劳现象之间的关系 ...
曾春华
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Gaoya dianqi, 2013 零件疲劳分析与计算对高压开关设备寿命预测起着至关重要的作用。笔者分析了高压开关传动系统关键零件疲劳的特点;建立了零件疲劳极限应力图模型,采用该模型可以计算出零件的疲劳极限与疲劳安全系数,并且可以估算在考虑安全系数前提下零件的疲劳寿命;以某高压断路器传动连杆的疲劳计算为例,对所采用的方法进行了验证。得出了3点结论:①有必要对高压开关零件进行疲劳分析和计算;②借助零件疲劳极限应力图可以较好地进行零件疲劳强度计算;③应力集中和零件材质对疲劳极限和寿命有较大的影响。
程立 +4 more
doaj
, 1980 疲劳问题跟工程机械和其它工业部门有着极为密切的关系。几乎所有工程机械都受重复交变载荷的作用,因而普遍存在着疲劳问题。据统计,工程机械大多数构件的破坏都是由于疲劳引起的 ...
曾春华
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, 2008 本文选择纳米晶与粗晶镍为实验材料,对其疲劳行为进行了实验研究。结果表明,纳米晶镍具有比粗晶镍更高的疲劳极限。AFM结果表明纳米晶疲劳后表面出现胞状起伏,晶粒尺寸没有发生明显改变 ...
谢季佳, 洪友士
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, 2004 以GCr15钢为实验材料进行旋转弯曲超高周疲劳行为的实验研究。用光学显微镜和扫描电镜对试样疲劳断口进行观察 ,结果显示 ,疲劳断裂周次从 10 6 直到 4× 10 8,GCr15钢疲劳裂纹大多起源于试样内部 ,裂纹源一般为非金属夹杂物。从内部起裂的试样 ,疲劳寿命一般比从表面起裂试样的寿命长。文中从断裂力学和断裂物理的角度 ...
周承恩, 洪友士
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Jianzhu Gangjiegou Jinzhan, 2009 车辆荷载反复作用下的疲劳损伤是影响钢桥运营安全和耐久性能的重要控制因素。新桥疲劳设计和既有桥梁评估应采用疲劳荷载。目前我国的桥梁规范还没有疲劳车辆荷载的取值规定。本文详细阐述了我国桥梁疲劳车辆荷载的疲劳设计状况和研究现状,系统介绍了几个发达国家桥梁疲劳车辆荷载的规范规定及其最新研究进展。本文还就建立适合我国国情的基于动态车辆称重WIM（Weigh-in-Motion）数据的车辆疲劳荷载模型或荷载谱作了初步的探讨性研究。
岳峰 +4 more
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