Results 11 to 20 of about 7,373 (134)
Carbon Material Films for Flexible and Efficient Electromagnetic Interference Shielding: A Review
Rare Metals, Volume 45, Issue 1, January 2026.ABSTRACT With the rapid development of technology such as the Internet and electronic devices, electromagnetic radiation pollution has become an increasingly prominent issue, which negatively impacts both human health and the normal operation of equipment.
Yu‐Xin Chen +10 more
wiley +1 more source
Park矢量模平方函数与ESPRIT相结合的异步电动机转子断条故障检测新方法
Gaoya dianqi, 2016 为了能够在异步电动机转子断条故障初发时准确检测并适时安排维修计划,提出利用Park矢量模变换技术与旋转不变信号参数估计技术谱分析方法相结合的方法进行异步电动机转子断条故障检测。经过Park矢量模平方变换可以将工频分量转换为直流量,即可轻而易举的消除工频分量的影响,结合ESPRIT高频率分辨力技术可以在短时采样信号下准确地检测出故障特征频率,与以往检测方法相比计算量大为减少。对一台异步电机分别进行仿真与实验验证,仿真与实验结果同时显示,该方法能够准确提取到转子断条故障特征信号,计算快速,频率分辨力高 ...
许伯强, 田士华
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Ultrasound 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
Shiyou jixie, 2014 为了准确实现内燃机气门间隙异常的诊断，提出了基于频带能量特征向量时频域特征的气门间隙故障诊断方法。介绍了小波包改进算法原理及频段能量计算，并以S195 四冲程柴油机为研究对象，测取气门间隙正常、进气门间隙异常和排气门间隙异常等不同工况下的缸盖振动加速度信号，并对其进行改进小波包分解处理，通过6～8 kHz高频带能量的故障阈值和分析信号时域内气门开启、关闭时刻对应的曲轴转角的变化确定进气门或排气门间隙异常，试验结果表明采用该方法诊断出各工况的故障与实际故障吻合。因此 ...
李阳龙, 王立勇, 栾忠权, 陈涛
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Gaoya dianqi, 2022 断路器分合闸过程中不可避免产生微米级金属粉尘，对GIS设备内部绝缘状态具有重要影响。文中以真型363 kV GIS为基础，搭建了可进行520 kV工频耐压、1 175 kV雷电冲击耐压的试验平台，用以开展微米级异物下GIS设备绝缘状态影响研究。首先基于2 000次机械操作开展微米异物分布特征研究，获取了触头不同磨损次数下的微米级异物变化趋势。其次在不同操作次数下采用脉冲电流法进行放电量检测，同时联合特高频、超声波局部放电检测法，分析不同检测方法对微米级异物放电检测灵敏度 ...
牛勃 +5 more
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Finding floral and faunal species richness optima among active fire regimes
Conservation Biology, Volume 39, Issue 6, December 2025.Abstract Changing fire regimes have important implications for biodiversity and challenge traditional conservation approaches that rely on historical conditions as proxies for ecological integrity. This historical‐centric approach becomes increasingly tenuous under climate change, necessitating direct tests of environmental impacts on biodiversity.
Zachary L. Steel +8 more
wiley +1 more source
Dianci bileiqi, 2019 杆塔接地诊断有着重要作用。杆塔有其独有的特点,开发针对杆塔诊断的新方法有其必要性。运用CDEGS软件仿真分析电源单端注入、中端注入、交叉点注入3种不同方式下接地导体的频谱响应特性,探讨注入方式的不同对频谱响应曲线的影响,为新方法的提出提供思路。研究发现,不同的接地方式有相似的频谱特性;针对不同参数,接地方式的不同会使频谱响应曲线有差异:当半径变化时,不同接地方式的频谱曲线之间的差异几乎不变;当土壤电阻率变化时,土壤电阻率越大,差异越大。
杨琳 +4 more
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Role of low‐impact‐factor journals in conservation implementation
Conservation Biology, Volume 39, Issue 2, April 2025.Abstract Academic review, promotion, and tenure processes place a premium on frequent publication in high‐impact factor (IF) journals. However, conservation often relies on species‐specific information that is unlikely to have the broad appeal needed for high‐IF journals.
Jonathan J. Choi +8 more
wiley +1 more source
Gaoya dianqi, 2017 输电线路零序参数是电网非全相短路电流、非全相开合电流计算,接地故障点位置确定,零序保护定值计算等工作的重要基础。针对1 000 k V皖南—浙北特高压线路零序参数测试的抗干扰问题,提出了"并联电容补偿与大容量变频电源相结合"的测量方法。测试数据分析结果表明:提高试验电源容量,可提高测量信号的信噪比,有效降低邻近线路感应电压干扰的影响。采用并联电容补偿方法,可降邻近线路产生感应电流对零序阻抗参数测试的影响。工频变相量法和异频法测量结果较为接近,但与理论计算值均存在一定差异,皖南 ...
王少华 +5 more
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Community Engagement and Ecosystem Services for Mine Rehabilitation 社区参与与生态系统服务在矿区修复规划中的应用
Integrative Conservation, Volume 4, Issue 1, Page 107-112, March 2025.Our study presents a community engagement process informing post‐mining land use in the Philippines through an ecosystem services lens. We conducted a participatory workshop at the Padcal Mine site to assess local perspectives on ecosystem services and mining impacts.
Yuan Pan +4 more
wiley +1 more source