Results 21 to 30 of about 802,127 (203)
Dizhen xuebao采用间接边界元法，结合Biot饱和多孔介质理论，建立了层状饱和场地中二维建筑群模型，其中上部结构采用多质点模拟，基础采用刚性方形基础模拟，进而研究了场地-建筑群动力相互作用对结构动力响应的影响。数值分析表明，场地-建筑群效应可能显著改变结构动力响应，即使结构参数相同，建筑群中不同位置结构的动力响应也可能存在显著差异。相较于仅考虑场地-单体结构动力相互作用的结果，场地-建筑群效应可能减小或增大结构位移响应峰值，这与结构之间距离、结构动力特性、场地特性等因素相关。本文算例中场地 ...
Hai Zhang +5 more
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建筑工程与管理为揭示既有沥青路面在移动荷载下的动力响应与破坏机理，此文采用数值模拟方法，系统研究了轴载速度和大小对含有两条横向基层反射裂缝路面结构的影响。结果表明，路面动力响应存在显著的临界车速效应，在车速达到108km/h时，路面结构的宏观应力因共振作用达到峰值，表明此速度下的损伤最为严重；贯穿裂缝是应力响应的主要控制点，而位移响应的控制点随着车速变化在两条裂缝之间动态“漂移”；贯穿裂缝处的剪应力和II型应力强度因子远高于拉应力和I型应力强度因子，表明其破坏主要由剪切作用主导；轴载大小与所有响应指标呈线性关系 ...
Chen Qiao, 吉 泽中
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Dizhen xuebao, 2022 研究不同时频特性的地震波作用下，抗震结构和隔震结构耦合设备的动力响应，对五层钢框架振动台模型试验数据进行小波分析。结果表明：主结构动力响应与地震波时频特性直接相关；由于主结构和隔震支座的滤波作用，设备的动力响应受地震波时频特性影响显著，但不具有直接相关性；隔震结构可以使设备的频率远离主结构的频率，从而降低设备的放大系数；设备耦合之后主体结构加速度的变化趋势取决于不同时频特性的地震波能量分布。
Miao Han +3 more
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Functional Ecology, EarlyView.Read the free Plain Language Summary for this article on the Journal blog. Abstract Atmospheric nitrogen deposition disrupts plant–herbivore interactions, but its impact on leaf volatile organic compounds (VOCs)‐mediated multi‐trophic herbivore resistance remains unclear within the context of plant invasion. In this study, we initially investigated the
Wanci He +7 more
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Plant invasion in mountain ecosystems reduces soil micro‐food web complexity at higher elevations
Functional Ecology, EarlyView.Read the free Plain Language Summary for this article on the Journal blog. Abstract Anthropogenic activities have accelerated plant invasions in mountain ecosystems, impacting the structure and functions of native plant communities. Changes in above‐ground vegetation can drive shifts in below‐ground biota, yet the effects of plant invasions on soil ...
Runjie Jiao +8 more
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Functional Ecology, EarlyView.Read the free Plain Language Summary for this article on the Journal blog. Abstract Soil salinization and alkalization often suppress microbial functional activity, triggering negative feedback loops in microbial metabolism, degrading nutrients and agricultural productivity.
Yuqi Chen, Lingying Xu, Xu Zhao
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The collective application of shorebird tracking data to conservation
Conservation Biology, EarlyView.Abstract Addressing urgent conservation issues, such as the drastic declines of North American migratory birds, requires creative, evidence‐based, efficient, and collaborative approaches. The abundance of over 50% of monitored North American shorebird populations has declined by over 50% since 1980. To address these declines, we developed a partnership
Autumn‐Lynn Harrison +71 more
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Emerging applications of large language models in ecology and conservation science
Conservation Biology, EarlyView.Abstract Large language models (LLMs) mark a major development in artificial intelligence, with potentially transformative implications for ecology and conservation science. Built on advanced deep‐learning architectures, these models can support a wide range of tasks. We reviewed emerging applications of LLMs, drawing on the wider scientific literature
Christos Mammides +5 more
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Haiyang gongcheng zhuangbei yu jishu, 2017 研究自升式平台动力放大因子的随机波动态响应分析法，以某自升式钻井平台为例进行动力放大因子分析，结果显示流速越大，流对平台动态和静态运动响应的抑制越显著，平台动力放大因子随着流速增大而减小。进一步进行算例平台的惯性力分析，结果显示随机波动态响应分析法能够考虑流速的影响，该方法得到的惯性力增大相对平缓。研究表明，流速较大时使用随机波动态响应分析法确定自升式平台的动力放大因子和惯性力，能优化桩腿设计，避免无谓的结构加强，有利于增大平台的可变载荷设计指标。
马网扣, 袁飞晖
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Gaoya dianqi, 2022 以2020年"黑格比"台风中倒塔的海岛大跨越塔线体系为研究对象,分析了"黑格比"台风对洞头海岛电网的影响,采用Ansys建立了裸塔及塔线体系的有限元模型,分析了裸塔和塔线体系的动力特性。其次,结合现有规范开展了输电塔线体系风荷载静力加载及脉动风速时程拟合方法研究,分别开展了0°、90°等风向角下静力分析和动力时程分析,得到了裸塔、塔线体系中输电塔位移、主材应力静载响应和风振响应,不仅对比分析了裸塔、塔线体系输电塔的风荷载静载效应与考虑脉动风的风振响应,还对比了不同风向角对输电塔风载效应的影响。此外 ...
朱云祥 +5 more
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