Results 21 to 30 of about 275,175 (145)
, 2020 变截面梁可以简化为由多段阶梯梁所组成,简化的段数越多,结果越精确。因此,基于Timoshenko梁理论,运用连续体传递矩阵法建立阶梯梁振动微分方程,并求解阶梯梁在考虑惯性效应移动载荷作用下的受迫振动响应;改变移动载荷的质量、速度和加速度,研究移动载荷参数对惯性效应的影响。与Euler梁模型和有限元模型的对比表明,该方法精度良好。选取悬臂梁自由端端点进行分析,结果表明,移动载荷的质量、速度和加速度增大,惯性系数也增大;质量是影响惯性效应的主要因素。当移动载荷的质量很小时 ...
王禹, 李宏亮, 龚云轩, 汤占洲
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Rare Metals, Volume 45, Issue 9, September 2026.ABSTRACT Aiming at the problems of insufficient forming quality and poor surface performance in the preparation of Ti‐6Al‐4V alloy by laser powder bed fusion (LPBF), this study proposed a laser in situ forging additive manufacturing (LIF‐AM) technology, which integrates LPBF with femtosecond laser in situ shock forging and realizes defect control and ...
Peng He +10 more
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Rare Metals, Volume 45, Issue 8, August 2026.ABSTRACT Many metallic components are frequently subjected to coupled environments of friction and vibration, stemming from interfacial contact and relative motion between mating parts or external stimuli. Consequently, it is imperative for these components to exhibit a synergy of high wear resistance and superior damping properties.
Ze Pu +12 more
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Dianci bileiqi, 2007 导线振动可引起鞭击闪络事故,严重时可造成断杆、短线及倒杆等事故。风的作用是造成架空导线振动的主要原因。从导线的振幅、振动角及风速对导线的冲击频率、导线的振动波长等几个参数以及架空导线受力情况,对导线振动进行了分析。得出导线振动的特征:在导线振动过程中,同频率振动波的波节和波腹的相对位置是固定的。最后,应用VB设计程序实现了导线振动的计算机仿真。
孙晓光, 安利强
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Rare Metals, Volume 45, Issue 7, July 2026.ABSTRACT Developing high‐efficiency catalysts for the seawater urea oxidation reaction (UOR) is pivotal to advancing hydrogen production via seawater electrolysis. Defect engineering has established itself as a core strategy for regulating catalytic activity.
Xiaoyu Wu +11 more
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Gaoya dianqi, 2019 为进一步研究高压电抗器振动机理及特性,针对一台油浸式并联电抗器,根据其结构特点和受力情况,建立了绕组与铁心的振动数学模型,理论分析了电抗器振动特性;对油浸式并联电抗器进行振动实验,研究了不同测点的振动特性、最佳测点的选择、不同电压下振动变化规律与振动信号特征频率。研究结果表明:电抗器振动频率以100 Hz为主,内部铁心饼表面振动幅值最大,在油箱外部采集的振动信号与内部具有相同的振动特性,可以反映电抗器内部运行状态。研究结果为电抗器减振降噪以及基于振动法分析电抗器故障提供了有效信息与有效依据。
魏旭 +7 more
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He jishu上海硬X射线自由电子激光装置X光束传输距离超过1 km，反射镜的角度振动对实验站样品处的光斑影响很大。本文旨在探讨动力吸振器在减小反射镜角度振动的可行性。针对反射镜角度14.6 Hz的环境振动，设计了一个可变刚度的动力吸振器，将其应用于上海硬X射线自由电子激光装置的反射镜调节系统中，以期实现该频率的振动抑制。实验结果表明，通过将动力吸振器的频率调至14.6 Hz，反射镜调节系统14.6 Hz的振动从154 nrad降低至27.9 nrad，其他频率的振动基本无明显变化，整体反射镜角度的振动从193.2 ...
袁 浩然 +6 more
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Ultrasound in Obstetrics &Gynecology, Volume 68, Issue 1, Page 88-98, July 2026.ABSTRACT Objective To identify prenatal predictors of tuberous sclerosis complex (TSC) in fetuses with one or more cardiac rhabdomyomas (CR), evaluate an integrated multimodal diagnostic workflow using fetal magnetic resonance imaging (MRI) and trio whole‐exome sequencing (trio‐WES) and characterize perinatal outcomes.
X. Cai +8 more
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Gaoya dianqi, 2019 变压器绕组和铁心的振动决定了油箱振动和变压器整体的声辐射水平。以往研究忽略了因结构连接而引起的铁心和绕组之间的耦合振动,简单地认为铁心和绕组的振动相互独立、互不影响,因而所得结论并不能真实反映变压器内部的实际振动情况。为了全面了解油浸式变压器铁心和绕组的耦合振动特性,文中建立了基于光纤振动加速度传感器的试验平台,对一台三相50 kVA变压器进行了试验研究,获得了内部结构（绕组和夹件）在空载、负载和变负载条件下的振动特性。研究结果表明,变压器空载时,铁心振动向绕组传递引起绕组多频振动 ...
高树国 +6 more
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Higher Education Quarterly, Volume 80, Issue 3, July 2026.ABSTRACT Amid intensified global talent competition and domestic demographic pressures, China, Japan and South Korea (hereafter, ‘Korea’) have expanded their international student policies beyond attraction and recruitment to include stronger measures for post‐study employment and retention, repositioning international students as strategic populations
Lilan Chen, Yingxin Liu, Xin Li
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