Results 41 to 50 of about 14,502 (143)
Amazonian conservation across archipelagos of Indigenous territories
Conservation 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
Quantitative support for the benefits of proactive management for wildlife disease control
Conservation 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
Gaoya dianqi, 1992 【问】什么是异相接地故障?电力部门为什么要求在非有效接地系统中应选用通过异相接地故障开断试验的断路器? 【答】在中性点非有效接地系统中,在一相断路器的内侧和另一相断路器的外侧各产生一个单相接地的故障,称为异相接地故障。异相接地故障实际是一种特定的两相接地故障。在开断异相接地时,断路器首开相上将出现1.73倍相电压工频过电压 ...
林立生
doaj
Analysis on the Current Phase Compensation in Differential Protection for Transformer [PDF]
, 2013 分析了接线双绕组变压器微机差动保护相位补偿采用角接与算法相位补偿关系,变压器差动保护内部两相短路故障灵敏度与相位补偿关系,得出无论变压器中性点是否接地,相位补偿选择低压侧的方案对差动保护灵敏度有利。This paper analyzes the relationship between angle-connection phase compensation and the algorithm phase compensation using in the current phase ...
朱文强, 谢珍贵, 黄兴平
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Ultrasound 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
Dianci bileiqi, 2023 我国城市中低压配电网电容电流急剧上升且消弧线圈补偿效果欠佳，单相接地故障电弧难以自熄易产生弧光接地过电压及扩大事故，探究弧光接地故障的快速有效熄弧方法是保障配网稳定安全运行的基础。首先根据主动转移型消弧技术的工作原理，建立熄弧过程的等效电路，利用叠加定理推导熄弧时故障点电流计算公式，分析其与故障点位置、接地点过渡电阻、线路负荷电流等因素的关系；然后采用Matlab/Simulink搭建10 kV小电流接地系统单相接地故障模型，其中采用控制论电弧模型模拟单相弧光接地故障；最后通过设置典型的故障点位置 ...
李景丽, 任俊跃, 赵子敬
doaj
Research and Implementation on New Embedded Extra High Voltage Distance Protection System [PDF]
, 2009 近年来，随着我国国民经济的快速发展，国家加大了电力基础设施的建设，输电网络也越来越复杂，国家对电力系统的安全运行提出了更高的要求，而传统的嵌入式微机保护装置，由于其在硬件平台设计和软件原理、算法的局限性，越来越不适应电力系统日益复杂的网络构架和运行方式，不能准确识别系统故障或运行异常等情况，保护误动、拒动时有发生，给国民经济造成了重大损失，所以，开发新一代的微机保护已经成为电力系统专业的科研院所、生产厂家近几年研发方向的重点。 本课题研究的目的正是力求开发一种新型的嵌入式微机保护 ...
赵长兵
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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
Integrative 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
110 kV沙土变同等条件下不同中性点接地设备故障处理对比试验及其分析
Dianci bileiqi, 2018 2015年10月,国网江西省电力公司赣西供电分公司在同等条件下分别对自动消弧线圈和ZXC系列主动干预型故障相转移接地装置做了单相瞬时性接地故障、单相永久性接地故障处理试验。试验结果表明:自动消弧线圈由于补偿后的残流控制的不好,不能及时熄灭瞬时性接地电弧,对永久性接地故障接地选线的准确率仅为33%;ZXC系列主动干预型故障相转移接地装置能及时消除瞬时性接地故障,选线准确率达100%,能及时选出并切除永久性接地故障。确保了故障点的安全。
晏锋
doaj
An AC constant current power supply design based on linearity power amplifier [PDF]
, 2008 交流恒流源作为稳定电源的分支有广泛用途，其作为一项技术在电源的研究领域中有很重要的意义。其发展与科技的进步息息相关，在各个国家特别是发达国家的国民经济中占有十分重要的地位。近年来我国检测技术有了较大的提高，但同发达国家的电网检测技术相比，差距仍然很大，存在参数检测精度不高、抗干扰性较差,实时性比较差、电路设计复杂等缺点。针对这些问题，本课题建立了一个以AT89C51单片机为控制核心的恒流源控制系统，该系统具有速度快、精度高、实用性强、电路模块化等特点。 本课题已经顺利完成以下几部分内容： 1硬件控制系统：
周景迁
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