Results 31 to 40 of about 14,739 (118)

Amazonian conservation across archipelagos of Indigenous territories

open access: yesConservation Biology, Volume 39, Issue 2, April 2025.
Abstract Indigenous stewardship is essential to the conservation of biocultural diversity, yet conventional conservation models often treat Indigenous territories (ITs) as homogeneous or isolated units. We propose that archipelagos of Indigenous territories (AITs), clusters of ITs that span geographies but are connected through shared cultural or ...
Michael S. Esbach   +3 more
wiley   +1 more source

10~35 kV中性点非直接接地系统分相接地电容测试方法

open access: yesGaoya dianqi, 2008
10~35 kV电压等级电力系统一般根据单相接地电容电流的大小来防治弧光接地电压,因此须测量中性点非直接接地系统分相接地电容的大小。笔者介绍了利用偏置电容测量中性点非直接接地系统分相接地电容的方法,并分析获得了理论计算公式;把实际系统参数代入公式计算并与测试数据对比,表明该方法简单,数值计算准确,可不中断对用户供电,具有广阔的推广应用前景。
侯崇升
doaj  

Quantitative support for the benefits of proactive management for wildlife disease control

open access: yesConservation Biology, Volume 39, Issue 1, February 2025.
Abstract Finding effective pathogen mitigation strategies is one of the biggest challenges humans face today. In the context of wildlife, emerging infectious diseases have repeatedly caused widespread host morbidity and population declines of numerous taxa.
Molly C. Bletz   +2 more
wiley   +1 more source

Combined first‐trimester screening and invasive diagnostics for atypical chromosomal aberrations: Danish nationwide study of prenatal profiles and detection compared with NIPT

open access: yesUltrasound in Obstetrics &Gynecology, Volume 64, Issue 4, Page 470-479, October 2024.
ABSTRACT Objectives Our aim was to examine the prenatal profiles of pregnancies affected by an atypical chromosomal aberration, focusing on pathogenic copy‐number variants (pCNVs). We also wanted to quantify the performance of combined first‐trimester screening (cFTS) and a second‐trimester anomaly scan in detecting these aberrations. Finally, we aimed
K. Gadsbøll   +6 more
wiley   +1 more source

An integrated historical study on human–tiger interactions in China 中国人虎互动关系的综合性历史研究

open access: yesIntegrative Conservation, Volume 3, Issue 3, Page 183-195, September 2024.
Tigers are important for maintaining a variety of life in the world as they are the top predators in the food chain. Human–wildlife conflict, including conflicts between humans and tigers, has been a global issue throughout history. This article focuses on human–tiger interactions in China, discussing various types of conflicts and measures for ...
Zhihong Cao   +4 more
wiley   +1 more source

基于三相电流变化增量的单相接地故障判断的研究

open access: yesGaoya dianqi
为了解决单相接地故障处理存在高阻故障判断盲区的技术难题,对接地故障发生时三相电流变化增量进行研究。从理论分析和10 kV真型模拟试验两方面入手,分析单相接地故障网络,研究接地故障点前后三相电流变化增量的特征,结合10 kV真型模拟试验数据、提出完整判据,创新了一种采用三相电流的稳态变化量来判断单相接地故障方法。该方法通过多种类型10 kV真型单相接地故障试验,证明其能够对单相接地故障准确选相选线和故障定段,并具有精准判断高阻接地故障的技术优势,可普遍适用于中性点不接地、经消弧线圈和小电阻接地系统。
李智玲   +6 more
doaj  

电力电缆绝缘在线监测测量方法及判据设计

open access: yesGaoya dianqi, 2004
为了寻求简易而又实用的鉴别电缆故障的方法,提出了双端接地单相电力电缆、三相电力电缆以及多接地点单相和三相电力电缆接地电容电流的测量方法及绝缘状况的判定依据,设计了测量装置并已制成样机。此外,为了验证该方法及判据的有效,详细介绍了仿真模型。
陈天翔, 段建东, 陈天韬, 陈广
doaj  

单、双地网接地方式下配电变压器反变换过电压的分析与仿真计算

open access: yesDianci bileiqi, 2016
为评估双地网对配电变压器反变换过电压的抑制效果,推导了单双地网接地方式下低压侧不安装和安装避雷器时配电变压器的反变换过电压简化计算公式,根据推导的理论公式,分析了在配电变压器低压侧不安装和安装避雷器时双地网接地方式相比单地网接地方式对反变换过电压的抑制效果,并分析了双地网接地方式下高低压侧地网间距对配电变压器反变换过电压的影响,同时采用ATPdraw仿真建模,验证并修正了由理论公式推导得到的结论。研究表明:对于低压侧没有安装避雷器的配电变压器,双地网接地方式相比单地网接地方式对反变换过电压的抑制效果明显;
郭婷婷, 杨琪, 文习山
doaj  

小电阻接地系统单相接地故障地电位分布与人身安全性研究

open access: yesDianci bileiqi, 2019
在小电阻接地系统中,若线路发生单相接地故障将在故障点产生较大电流,数百安的接地电流会引起地电位超过安全允许值。对某市10kV小电阻接地系统发生单相接地短路后会造成地点位升高进行了定量分析。首先,对该线路在单相接地短路时故障短路电流进行了模拟理论计算和MATLAB仿真,得到故障发生后将产生超过安全允许的电流值。其次,运用有限元分析软件ANSYS分析了杆塔旁土壤地电位分布,并分析其跨步电压对人身安全的影响。结果表明:故障发生后杆塔附近的跨步电压较大,远远超过人身安全允许值。最后,基于人身安全 ...
毛兴华   +4 more
doaj  

基于零序功率及谐波相位综合法的小电流接地系统微机选线装置

open access: yesGaoya dianqi, 2006
针对现有的小电流接地选线装置选线准确率不高及存在选线死区等问题,通过分析小电流接地系统单相接地时的特性,综合分析各种选线方法,提出以采用目前稳态法中准确度最高的零序功率法为主判据,以5次谐波相位法为二次判据的选线方案。使用ATP仿真软件对某个110/10 kV变电站单相接地故障进行模拟,结果显示对于不同的接地电阻和接地位置,该判据均能准确判断出故障线路。由此设计了基于PC104工控机的新型小电流接地选线装置。
徒有锋   +4 more
doaj  

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