Results 21 to 30 of about 14,233 (144)
Monitoring population extinction risk with community science data
Journal of Applied Ecology, Volume 62, Issue 9, Page 2133-2147, September 2025.Our modelling framework provides a robust, computationally efficient and easy‐to‐apply tool for monitoring local persistence probability that can support global conservation efforts. This will complement the monitoring of species population viability in places where standardized monitoring is still lacking, but community science observations are common.
Orlando Acevedo‐Charry +8 more
wiley +1 more source
Analysis Based on the Simplified Sequence Component Method [PDF]
, 2013 分析了对称分量存在不足,结合平衡线路的模变换数学特性,得出简化序分量法在输电线路的故障分析原理。提出了简化序分量法在短路和断线故障分析及选相原理,解决了距离保护作为yd变压器远后备保护存在的问题。On the basis of an analysis of the disadvantages of symmetrical component,under consideration of mathematical characteristics of the modular transformation ...
谢珍贵, 黄兴平
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New Phytologist, Volume 247, Issue 5, Page 2086-2097, September 2025.Summary The importance of marine angiosperms, or seagrasses, as foundation species for marine coastal ecosystems is in marked contrast to their low species number of only 70 described taxa. Seagrass species tend to have very similar overall morphologies dictated by hydrodynamic forces of the ocean environment.
Xiaomei Zhang +14 more
wiley +1 more source
Gaoya dianqi, 2008 为了更好地应用小电阻接地方式来提高配电网系统的安全性、可靠性,笔者研究了中性点采用小电阻接地和消弧线圈接地的配电网在发生单相接地故障时的不同特点以及保护方式的差异。首先采用对称分量法对这两种配电网的单相接地故障进行分析,并采用MATLAB进行了仿真。研究结果表明,采用这两种接地方式的配电网在发生单相接地故障时的不同特点导致其继电保护措施也各不相同。因此,随着中性点经小电阻接地的接地方式的推广,其相应的单相接地故障继电保护措施需进一步完善。
李林, 冯勇, 郑剑飞
doaj
Dianci bileiqi, 2021 配电网中故障频发,其中多以单相接地故障为主,且常伴随着电弧的产生,严重影响配电网稳定。因此建立有效的电弧模型,对指导配电网单相接地故障定位与故障消弧,提高配电网供电可靠性,有重要作用。笔者首先对配电网单相接地故障电弧和实测波形特点进行总结分类,接着基于现场实验参数拟合,运用回归分析方法,在MATLAB仿真软件中分别以定值电阻、分段电阻、多项式电阻的形式建立了可变电阻电弧模型,该模型聚焦于接地故障电弧外在伏安特性的准确模拟上,拟合曲线函数不存在奇异点、计算效率高。仿真结果表明 ...
肖梓林
doaj
The Research and Logic Design of Microcomputer Auto Reclosing Device [PDF]
, 2011 随着现代电力系统日趋复杂和电压等级的不断提高，电力系统出现的问题也不断增加，因此，必须有足够的措施来保障系统的安全，将电力系统出现故障时所造成的损失降到最低，继电保护技术是各种安全措施中最为重要的一种。输电线路中的自动重合闸作为电力系统继电保护装置的重要组成部分，它在保证系统的稳定、安全和经济运行等方面都具有非常重要的作用。 由于重合闸逻辑的复杂性，以及不同用户使用的多样性，传统的重合闸逻辑方案已无法满足用户的需求。所以找到一种原理简单、判据准确且能方便地在各种实际线路中应用的新逻辑方案 ...
阮香西
core
Laser‐guided thin‐film self‐rolling for asymmetric small‐scale swimmers
Rare Metals, Volume 44, Issue 8, Page 5607-5620, August 2025.Graphical abstract AbstractSmall‐scale robots are promising miniaturized devices in biomedicine. Thin‐film self‐assembly is a commonly used strategy to fabricate tubular small‐scale robots. However, the existing methods have limitations like complex manufacturing processes and limited control of self‐assembly behavior.
Yi Chen +11 more
wiley +1 more source
Gaoya dianqi, 2003 随着中压电网中性点不接地供电网系统的不断扩大,单相接地电容电流也在不断增加,正确判别电网接地点,是关系到电网运行可靠性的关键技术问题。笔者就目前电网的单相接地选线方法进行了分析和探讨,指出采用零序电流相对相位法和零序电流5次谐波法选线所存在问题,提出利用单相接地故障时出现的零序分量的特点,从“能量”观点实现选线的新方法。
崔联广 +3 more
doaj
Study and Realize the Protection Device Base on the FREESCALE 56800 Family Dsp [PDF]
, 2010 电力系统自动化是自动化领域的一个主要分支，而微机型继电保护测控装置是电力系统中电气元件发生故障或不正常运行状态时，动作于断路器跳闸或发出信号的一种自动装置，是电力系统自动化的重要组成部分。现有微机保护装置大多基于传统的单片机，无法满足电力系统终端用户的高速度、高精度的特殊需求，随着电子技术发展，采用更先进的元件和更先进的方法来研究设计出能符合用户需求的产品，是行业的发展方向。本课题研究了国内外在继电保护方面先进的技术经验及最新的DSP技术的应用，提出了一种基于DSP内核的 ...
钟志斌
core
Joint Extraction Method for Spatial Relations in Chinese Geological Texts
Earth and Space Science, Volume 12, Issue 8, August 2025.Abstract Extracting spatial relations of geological entities is an important prerequisite for achieving natural language processing tasks such as geological knowledge question answering and semantic search, and is an important means to achieve structural reconstruction of unstructured geological data.
Chuan Chen +9 more
wiley +1 more source