Results 21 to 30 of about 485,059 (163)

Configuration Optimization Design of Magnetic Circuit for Large Magnetostrictive Devices Based on TbDyFe Alloy

open access: yesRare Metals, Volume 45, Issue 3, March 2026.
ABSTRACT Reliable operation of high‐performance magnetostrictive devices, composed of the giant magnetostrictive material (GMM), that is, the TbDyFe alloy, critically depends on an optimally tailored bias magnetic field. Sufficient intensity and uniformity are essential to induce the ideal initial strain in the GMM, enabling peak reciprocating output ...
Jinan Yu   +12 more
wiley   +1 more source

Undetected cases after implementation of first‐trimester anomaly scan in low‐risk population: insights from the IMITAS study

open access: yesUltrasound in Obstetrics &Gynecology, Volume 67, Issue 1, Page 27-33, January 2026.
ABSTRACT Objective To assess the effectiveness of the first‐trimester anomaly scan (FTAS) performed as part of a centrally steered national screening program in The Netherlands by investigating false‐negative cases with a fetal structural anomaly that was not detected at the FTAS.
K. Bronsgeest   +18 more
wiley   +1 more source

主动脉窦瘤的超声特点与漏诊分析 [PDF]

open access: yes, 2023
目的总结主动脉窦瘤(SVA)的超声特点,分析漏诊原因,探讨SVA的超声诊断技巧,提高诊断率。方法回顾性分析2014年1月至2022年3月期间在中山大学附属第一医院行外科手术的52例SVA患者的超声心动图特征及手术资料,按改良Sakakibara分型分为5型。结果52例SVA患者中,男性32例,女性20例,年龄18~66(36.1±11.6)岁。其中44例窦瘤起自主动脉右冠窦,8例起自无冠窦,未见起自左冠窦的病例。Ⅰ型、Ⅱ型和Ⅲv型为膨入右心室的窦瘤共35例,32例(91.4%)合并室间隔缺损(VSD ...
李翠玲   +4 more
core   +1 more source

Impact of fetal and maternal characteristics on the accuracy and precision of sonographic fetal weight estimation: population‐based study

open access: yesUltrasound in Obstetrics &Gynecology, Volume 66, Issue 6, Page 747-753, December 2025.
ABSTRACT Objective Ultrasound‐based fetal growth assessment is an essential part of clinical decision‐making in modern obstetric care. This study aimed to evaluate the impact of maternal and fetal characteristics on the accuracy and precision of sonographic fetal weight estimation.
M. Granfors   +4 more
wiley   +1 more source

Clip Voice: Misogyny and the Renegotiation of a Gendered Vocal Style in Chinese Digital Discourse

open access: yesJournal of Sociolinguistics, Volume 29, Issue 5, Page 348-359, November 2025.
ABSTRACT The participatory culture of social media allows women's voices to be heard but also parodied and policed. On Chinese social media platforms, where performers rapidly adopt and transform vocal trends for engagement, discourse on gendered vocal styles has proliferated.
Zichuan Yu, Rebecca Lurie Starr
wiley   +1 more source

水力压差式封隔器在裂缝性漏失井中的堵漏研究与应用

open access: yes, 2017
裂缝性漏失井在西峰油田比较常见,近年来随着西峰油田漏失区域的不断扩大,大型裂缝性漏失井也呈现逐年增加趋势,同时地层水也越来越活跃,大型漏失井漏失静液面逐年下降,漏层承压能力越来越弱,使用桥塞堵漏剂很难架桥封堵,而使用注水泥堵漏时,由于洛河上部出水、漏层内地层水活跃,水泥塞长度和成塞质量很难控制,往往受地层出水影响而无水泥塞,有些井虽然有较长段水泥塞,但是漏层处无水泥塞或水泥交接差,钻至漏层就立即失返,针对这些问题,研究引入了水力压差式封隔器注水泥,有效解决了以上问题。经过现场试验成功后现已推广使用 ...
保民 陈, 迁 张
core   +1 more source

LW6型液压机构内部渗漏分析判断及处理技巧

open access: yesGaoya dianqi, 2010
分析LW6型液压机构内部渗漏油的原因,指出了LW6液压机构出现内部渗漏的各种可能元件小部位:控制阀回油管、三级阀回油管、供排油阀回油管和压力组件回油管。通过图文并茂的形式,介绍了判断液压机构内部渗漏部位的方法技巧,并且结合实际现场典型故障处理事例,采用问、闻、切、望的故障判断方法,可快速判断故障部位。
张涛   +4 more
doaj  

户外高压少油断路器渗漏的处理

open access: yesGaoya dianqi, 1982
在运行设备中,常见到户外高压少油断路器出现渗漏油现象,既影响设备安全运行又有碍站容美观。如果渗漏点暴露在明处,可借停电小修机会进行补焊处理,但渗漏往往发生在三角腔的桃形板或A字滑道内焊缝处,处理起来十分不便。本文所介绍的是渗漏点处于后一种位置的处理方法。 首先将开关三角腔内油放到立套管部位,将渗漏处清理干净,并用蘸酒精的布或海绵将油腻擦净 ...
齐长善
doaj  

高压直流输电工程换流阀均压电极断裂机理研究

open access: yesGaoya dianqi, 2023
均压电极是高压直流输电工程换流阀内冷水系统的重要部件,起到钳制电势和减小泄漏电流的关键作用,但是在运行过程中,均压电极发生腐蚀或者断裂,将导致换流阀阀塔上与内冷水管道接触的金属器件发生腐蚀,内冷水系统发生渗漏、堵塞等,从而使得换流站因设备过热、水管漏水等问题造成的停运事件屡有发生,严重影响直流工程的安全稳定运行。因此,研究均压电极断裂相关机理和原因能够有效减小内冷水系统事故。文中通过分析均压电极在水管内的受力情况,结合铂金材料的特性,首次从剪切强度的角度开展了均压电极断裂分析。文中从材料成分、力学性能 ...
肖凯   +5 more
doaj  

基于泄漏扩散数值模拟的GIS室内SF6检测与回收策略

open access: yesGaoya dianqi, 2019
SF6因其优异的性能而广泛应用于电力工业,但SF6气体泄漏故障时有发生,威胁着大气环境、电气设备及运维人员人身安全。文中以某GIS室内盆式绝缘子开裂导致的气体泄漏事故为例,基于计算流体力学模型,开展真型尺寸GIS室SF6泄漏气体分布规律研究,掌握了GIS室内站SF6泄漏扩散分布规律。研究发现:SF6由开始外泄到均匀分布,会经历喷射、重力扩展、空气卷吸及被动扩散等4个阶段。进一步提出了SF6泄漏气体的回收策略,在0.3 m水平面合理布置SF6检测装置,能在10 s内快速高效检测到外泄气体;30 ...
周松霖   +4 more
doaj  

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