Results 31 to 40 of about 126 (113)
How Many Floods Have Occurred in China in the Past Decade? A Perspective From Social Media
Earth's Future, Volume 13, Issue 4, April 2025.Abstract Global climate change has led to frequent and widespread flood disasters in China. Traditional flood disaster investigations mainly focus on major flood events, and small‐scale flood events are often overlooked. This study utilized the Sina Weibo social media platform to detect flood events in 370 cities in China from 2012 to 2023.
D. Shen +5 more
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Conservation Biology, Volume 38, Issue 5, October 2024.Abstract Illegal collecting of wild Venus flytraps (Dionaea muscipula) for the horticultural trade represents a persistent threat to populations of the species across their endemic range in the coastal plain of North and South Carolina (United States). Although wild collecting of Venus flytraps is not a novel threat, there has been very little research
Jared D. Margulies +10 more
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Risk, Hazards &Crisis in Public Policy, Volume 15, Issue 2, Page 261-283, June 2024.Abstract Disaster‐specific Facebook groups (DSFGs) are Facebook groups devoted to a specific disaster or set of disasters. I argue DSFGs offer opportunities for disaster response and resilience organizing that can mitigate the limitations of institutionalized disaster response and illustrate the benefits and detriments of the use of DSFGs by survivors ...
Bailey C. Benedict
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Jianzhu Gangjiegou Jinzhan, 2021 现行《建筑钢结构防火技术规范》(GB 51249—2017)未给出火灾下钢结构的局部稳定设计方法,为了获得轴心受压焊接H形高强Q690钢柱高温下的局部稳定性能,考虑钢材高温下力学性能退化、截面高温下焊接残余应力降低及初始几何缺陷,采用ABAQUS软件建立经试验验证的高温局部稳定分析有限元模型,得到焊接H形高强Q690钢柱在不同温度下的局部屈曲应力和极限应力。研究表明:当温度低于550℃时,钢柱在高温下和常温下屈曲应力具有相同的变化趋势;高温下的残余应力值和初始几何缺陷对屈曲应力有较大的影响 ...
李翔, 王卫永, 于克强
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Experimentally testing animal responses to prescribed fire size and severity
Conservation Biology, Volume 38, Issue 3, June 2024.Abstract Deserts are often highly biodiverse and provide important habitats for many threatened species. Fire is a dominant disturbance in deserts, and prescribed burning is increasingly being used by conservation managers and Indigenous peoples to mitigate the damaging effects of climate change, invasive plants, and land‐use change. The size, severity,
Tim S. Doherty +4 more
wiley +1 more source
Integrative Conservation, Volume 3, Issue 1, Page 58-75, March 2024.Local populations are aware of the decline and disappearance of Detarium species in their habitats, attributing this trend to excessive human exploitation and the effects of climate change. Thus, Detarium plant resources may face challenges in forests with different levels of protection status due to habitat fragmentation and the effects of climate ...
Adama Taonda +4 more
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Jianzhu Gangjiegou Jinzhan, 2018 采用基于有限元理论开发的ANSYS软件建立了张弦梁数值分析模型,按温度增量法对其火灾历程中的力学反应进行分析。讨论了在升温历程中,温度场非均匀性、荷载比、垂跨比、火源半径、火源位置以及支座约束对张弦梁上弦钢梁及下弦预应力索力学特征的影响以及跨中挠度的变化历程。得出以下结论:随着温度分布非均匀性的减小,在升温历程中,上弦钢梁强度应力历程下降速率增大,而稳定应力呈先增加后下降趋势,下弦索应力变化很小;随着荷载比增大,结构临界温度降低,结构跨中挠度增长速率也变大;随着垂跨比的增大,结构受火失效截面位置发生改变,
张浩, 杜咏, 盛红梅, 王惠蕾
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Jianzhu Gangjiegou Jinzhan针对局部火灾，需要考虑建筑物构件不均匀受热情况下的热学与力学响应。研究对象为方钢管梁，模拟其在不同高度处承受底部火羽流冲击作用的热力学现象。有别于应用绝热表面温度概念来实现流固传热的单向迭代耦合，本文提出一种新的CFD-FEM数值模拟手段，通过将火灾分析模块与热分析模块统一采用CFD方法开展来实现流固传热界面的双向直接耦合。首先通过典型局部火灾试验为例进行了该数值方法的准确性验证。继而在火灾模块中探究了空间速度场与温度场的分布规律，在热模块中探究了不同高度处钢梁的壁面热流的变化规律 ...
周靖罡, 王伟, 周晅毅, 丛北华
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火灾下非均匀受火钢柱截面温度分布规律及其对钢柱抗火性能影响的研究现状
Jianzhu Gangjiegou Jinzhan, 2011 本文介绍了火灾下非均匀受火钢柱截面温度分布规律及其对钢柱抗火性能的研究进展和已有研究成果,包括钢柱截面非均匀温度分布产生的原因及截面温度非均匀分布对钢柱抗火性能的影响。钢柱截面不均匀温度产生的原因有:钢柱受到建筑填充墙保护,非4面受火;钢柱仅部分截面采用防火保护;受洞口非均匀火灾影响的建筑外框架柱;钢柱防火保护层不均匀或局部破损等。截面温度不均匀对钢柱抗火性能的影响包括:截面产生附加应力,使钢柱临界温度降低;钢柱截面不对称,发生弯扭破坏;钢柱产生热弯曲,以及破坏时可能出现的反向弯曲等 ...
潘锦旭, 张盛亚, 王培军
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Jianzhu Gangjiegou Jinzhan, 2022 为研究钢管超高性能混凝土在标准火灾下的受力性能和破坏机理，建立了钢管超高性能混凝土柱的耐火有限元模型，并重点对比分析了超高性能混凝土与部分其他类型混凝土的热工参数及高温下本构关系的不同对构件温度和耐火极限等的影响，结果表明：钢管超高性能混凝土构件的核心混凝土温度明显高于相应的普通钢管混凝土或钢管高强混凝土构件的核心混凝土温度，且对于不同配合比的超高性能混凝土构件，其核心混凝土温度场也存在一定差异；高温下钢管对核心超高性能混凝土的约束作用可以忽略不计；对于不同长细比的构件 ...
张旭 +4 more
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