Results 11 to 20 of about 262,975 (157)

K418与42CrMo异种金属激光焊接缺陷形成机制

open access: yes, 2008
研究了镍基高温合金K418与合金钢42CrMo异种金属激光焊接焊缝缺陷的形成机制。通过光学显微镜观察了焊缝的宏观缺陷;通过扫描电镜观察了焊缝的微观缺陷,并使用能谱仪测量了焊缝缺陷处和枝晶核的成份。研究结果表明:K418和42CrMo异种金属激光焊接焊接参数选择不合理,焊缝易形成塌陷、气孔和裂纹等缺陷;焊缝区域的热裂纹是和焊接过程晶界形成的低熔物密切相关;在焊接试样被焊透的条件下,提高焊接速度可以避免焊缝塌陷 ...
王立新   +4 more
core   +2 more sources

Recent Advances in Piezocatalysis and Piezo‐Photocatalysis in Energy and Environment: Materials, Design, and Applications

open access: yesRare Metals, Volume 45, Issue 4, April 2026.
ABSTRACT Piezocatalytic technology utilizes mechanical strain or stress‐induced piezoelectric phenomena to produce robust internal electric fields, markedly improving the separation efficiency of e−‐h+ pairs. This method has emerged as a focal point in catalysis by removing reliance on conventional light or electrical energy via its mechanical‐to ...
Yue Zhou   +5 more
wiley   +1 more source

The Dependence of Properties on Structural Features in Macro/Micro Levels for PBF‐LB Fabricated Porous NiTi Alloy

open access: yesRare Metals, Volume 45, Issue 2, February 2026.
ABSTRACT Porous NiTi alloys are widely used in biomedical and engineering fields. Using the PBF‐LB technique, the TPMS and Voronoi porous parts with a porosity of ∼67% and a minimum feature size of 0.15 ± 0.02 mm were fabricated. Although the bulk sample fabricated with the same parameters is defect‐free, μ‐CT reconstruction on the porous sample ...
Wen‐Hao Zeng   +7 more
wiley   +1 more source

GIS机械振动和局部放电融合检测系统研究

open access: yesGaoya dianqi, 2023
气体绝缘组合开关潜在性的绝缘缺陷和机械缺陷是导致其发生故障的主要原因,因此同步检测GIS设备内部绝缘状态和机械状态,对电力系统的正常运行具有重要的现实意义。文中从GIS的实际检测需求出发,设计振动—超声融合传感器,搭建融合检测系统。系统基于小波包算法实现对融合信号的分离与去噪,并利用振动基频信号获取工频电压相位,作为局部放电PRPD(partial discharge phase distribution)谱图的相位参考信息,检测系统可综合实现振动—超声融合信号采集、调理转换、处理分析等功能 ...
蒋科若   +5 more
doaj  

Dual‐Rare‐Earth‐Doped Piezoelectric Semiconductor Gallate Solids With Spectral Tuning for Energy Conversion and Photonic Applications

open access: yesRare Metals, Volume 45, Issue 1, January 2026.
ABSTRACT Mechanoluminescent materials have gained significant attention for their unique capability to convert mechanical stimuli into light without external optical or electrical excitation, holding immense promise for applications in safety monitoring, biomedicine, optical anti‐counterfeiting, and intelligent sensing.
Fanlei Qin   +8 more
wiley   +1 more source

随机缺陷对蜂窝结构动态行为影响的有限元分析

open access: yes, 2009
通过对胞壁随机移除的蜂窝结构动态变形过程的有限元模拟,分析了随机缺陷对蜂窝结构变形模式的影响,得到蜂窝结构在两个加载方向上的变形模式图及不同模式间转换的临界速度. 对含缺陷蜂窝结构平台应力的研究发现,当变形模式为过渡模式或动态模式时结构平台应力与冲击速度的平方成线性关系.
寇东鹏, 虞吉林, 郑志军
core   +2 more sources

GW7—220型隔离开关检修要点

open access: yesGaoya dianqi, 1990
我单位有平顶山高压开关厂生产GW7—220型隔离开关43组,运行时间分别为:10年的17组,7年的4组,5年的10组,两年以内的12组。根据该设备运行中暴露的缺陷,我们对所有该型隔离开关都进行了解体大修,现将我们发现的缺陷及处理方法介绍如下,供各位同行参考。 该型隔离开关可分为导电系统和机械传动系统两大系统。导电系统的主要缺陷是零部件的机械强度问题;机械传动系统的主要缺陷是各齿轮、联轴转动部分的润滑问题。
邹鸣鸣
doaj  

基于X射线三维成像技术的在役GIS盆式绝缘子缺陷检测

open access: yesGaoya dianqi, 2022
在役GIS盆式绝缘子因材质性能欠佳、机械操作振动等原因会引入气隙、金属微粒等各类缺陷,若不通过诊断提前预警并及时处理,极有可能引起突发性故障。X射线检测作为一种重要的可视化检测方法,在应用于在役GIS盆式绝缘子时存在检测效率低、结果不直观、存在检测盲区等问题。文中设计了在役GIS盆式绝缘子的X射线检测智能定位装置,开发了GIS盆式绝缘子缺陷检测的三维成像技术。结果表明,文中开发的X射线三维成像技术,可实现成像板及射线机的自动升降和多角度旋转控制、三维图像的智能重构以及GIS盆式绝缘子的全覆盖照射 ...
张国宝   +6 more
doaj  

基于分合闸线圈电流的断路器缺陷诊断及试验方法研究

open access: yesGaoya dianqi, 2015
分合闸线圈是断路器操作机构的关键部件。笔者通过深入研究断路器分/合闸线圈电流波形与机械缺陷之间的关系,提取线圈电流波形中的关键特征量,建立其与断路器常见典型机械缺陷的诊断判据,并通过实验室断路器缺陷模拟试验平台进行验证。基于研究结果,提出在国内开展断路器"首次分/合闸"时线圈电流检测试验的具体实施方案并进行风险评估,通过试验提前发现断路器机械方面存在的缺陷,有效指导国内电网断路器设备状态检测策略。
李大卫   +3 more
doaj  

Auto-focus technology and its application based on image processing [PDF]

open access: yes, 2009
Auto-focusing technique is an important method to improve the precision,intelligentization,automatization for the indentation diameter measurement.The paper introduces an auto-focus method of indentation diameter measurement based on image processing ...
Chen, Xiaomei, Yang, Tao, Zuo, Yong
core   +2 more sources

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