Results 1 to 10 of about 7,356 (116)
Abstract Invasive species can dramatically alter ecosystems, but eradication is difficult, and suppression is expensive once they are established. Uncertainties in the potential for expansion and impacts by an invader can lead to delayed and inadequate suppression, allowing for establishment.
Brian D. Healy +5 more
wiley +1 more source
Abstract As ecological data and associated analyses become more widely available, synthesizing results for effective communication with stakeholders is essential. In the case of wildlife corridors, managers in human‐dominated landscapes need to identify both the locations of corridors and multiple stakeholders for effective oversight.
Jay M. Schoen +13 more
wiley +1 more source
随着我国高速铁路的广泛延伸,直流接地极与高速铁路相接近的情况时有发生。直流接地极入地电流可能会对高速铁路综合接地系统造成影响。为了评估直流接地极对高速铁路综合接地系统的影响情况,文中建立了高速铁路综合接地系统的直流电流分布的分析模型,获得了高速铁路沿线轴向直流电流分布和单位长度泄漏电流密度分布,说明了直流接地极对高速铁路综合接地系统的电腐蚀影响机理,并分析了土壤电阻率、直流接地极距离等因素对电腐蚀程度的影响。研究结果表明,直流接地极对高速铁路综合接地系统有一定的电腐蚀影响 ...
宋伟 +4 more
doaj
目的 本国际临床指南由欧洲残疾儿童学会(the European Academy of Childhood Disability,EACD)牵头制定,旨在解决发育性协调障碍(developmental coordination disorder,DCD)的定义、诊断、评估、干预以及与社会心理方面的临床应用关键问题。 方法 本指南针对五个领域的关键问题,通过文献综述和专家团队的正式讨论达成共识。为保证指南的循证基础,以“机制”、“评估”和“干预”为检索词, 对2012年更新以来提出的最新建议以及新增的“社会心理问题”和“青少年/成人”为检索词进行检索。根据牛津大学循证医学中心证据等级 (证据水平 [level of evidence, LOE]1–4) 将结果进行分类,最终转化为指南建议。并由国际 ...
Jing Hua +6 more
wiley +1 more source
良好的接地系统对于风电机组的正常运行至关重要。基于风机接地圆环的不等电位模型研究雷电流波头时间与入地点、雷电流幅值、土壤击穿场强、土壤电阻率等因素对风电机组接地系统雷电冲击特性的影响规律以及多年冻土地区通过对接地网敷设垂直接地极的散流效果。结果表明:雷电流经风机接地圆环中心注入时具有更好的散流效果,雷电流波头时间越短,接地导体的电感效应越强烈,风机冲击接地电阻越大;随着雷电流幅值的增加,土壤的火花效应得以加强,风机接地圆环面积越小,冲击接地电阻降低越明显;土壤临界击穿场强越小 ...
姜龙杰 +5 more
doaj
Evolvable Transformer Fault Diagnosis Model Combining Feature Analysis and Machine Learning [PDF]
Transformers, which possess complex mechanisms and exert an extensive influence, are important equipment in large power systems. The state detection and fault diagnosis of transformers are hence a key challenge in traditional power systems; they also ...
Yedong MAO, Chunhui ZHANG, Jie CHEN
core +1 more source
本文介绍了位移电压法计算对地电容的原理。利用Matlab仿真平台,建立了中性点经消弧线圈接地的电网模型。在此模型基础上针对位移电压法的准确性进行了仿真实验。仿真结果表明利用位移电压法能够准确地计算出对地电容,相对误差控制在1 ...
唐琦, 柯远青, 陆达
core
Summary of Desert Photovoltaic Power Transmission Technology [PDF]
To achieve carbon peaking and carbon neutrality goals and improve energy efficiency, new energy plays a major role in China strategic deployment. However, as centralized photovoltaic is located in desert areas, photovoltaic power transmission has become ...
CHU Shuai +5 more
core +1 more source
ABSTRACT Piezocatalysis has garnered unprecedented research enthusiasm for applications in energy and environmental fields, as it can harvest the tiny vibration energy from the natural environment and convert it into electrical energy to drive catalytic reactions.
Feixue Gao +9 more
wiley +1 more source
Research and Simulation of Resonant Grounded System Based on Controlled Magnetic Flux [PDF]
我国中压配电网,绝大多数采用中性点不接地方式。这种接地方式最大的优点是:当发生单相接地时,三相线电压的对称性没有被破坏,所以用户用电不受影响,可维持一定长的时间。但是,当配电网达到一定规模,对地电容电流达到一定数值后,必须采取加装消弧线圈的措施来保证配电网的安全。 配电网中性点采用消弧线圈接地的方式,对于改善电网供电质量、提高供电可靠性和保证整个系统安全运行都有十分重要的意义。本文在此背景下,对建立大范围连续调节电感电流、谐波较少的消弧线圈补偿模型 ...
桂亮
core

