Results 11 to 20 of about 16,885 (222)
Integrative Conservation, EarlyView.This research reveals the functional stability of mixed species foraging flocks (MSF) and their foraging height change with different taxonomic differences along the elevational gradient at Knuckles Montane Reserve, Sri Lanka. This offers new insights into how MSFs sustain with the elevational gradients supporting the altitudinal shifting species ...
Vimukthi. R. Gunasekeara +3 more
wiley +1 more source
Integrative Conservation, EarlyView.We collated detections of the sun bear from new and previously published camera trap studies across its range. We then analysed these detections at two different spatial scales to assess the habitat associations and diel activity of this species. We found that the sun bear is tolerant to moderate habitat disturbances. ABSTRACT Degraded tropical forests,
Alexander Hendry +5 more
wiley +1 more source
Study on Vibration Characteristic of Operational Bridge Based on Monitoring Data [PDF]
, 2016 桥梁结构监测系统能够对结构进行实时自动的状态监测，为评价运营桥梁的承载能力、使用功能和安全可靠性提供数据基础。近年来因为缺乏科学监测与管理所引起的桥梁垮塌事故频频发生，因此有必要利用监测数据对重要大桥的结构运营状态进行评估。本文基于厦门天圆大桥结构监测系统的实测数据，对单拱肋中承式梁拱组合桥型的振动特性进行研究，重点包括大桥的模态参数识别与短吊杆疲劳寿命估计两方面。本文主要工作内容如下： 首先，阐述了桥梁结构监测系统与模态分析方法的发展现状，总结了中承式拱桥结构特点与短吊杆疲劳问题 ...
何文朋
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A link between increased temperature and avian body condition in a logged tropical forest
Conservation Biology, EarlyView.Abstract The combined effects of anthropogenic disturbances, such as logging and climate change, remain poorly understood; yet, they are the main threats to tropical biodiversity. Most tropical African countries lack long‐term climate data, so climate impacts on biodiversity cannot be assessed.
Moreen Uwimbabazi +7 more
wiley +1 more source
Research on Structural Design and Mechanical Behavior of Double Arc Tooth Profile Harmonic Drive [PDF]
, 2015 谐波齿轮减速器是一种传动精度高、减速比大并能够在密闭空间传动的齿轮传动机构，应用领域广泛，尤其在航空航天领域有不可替代的优势。常用的渐开线齿廓齿根处会出现应力集中以及齿顶产生尖点啮合现象，影响其承载性能和啮合质量。双圆弧齿形谐波齿轮以其良好的承载能力与啮合性能逐渐成为研究热点，本文根据谐波齿轮设计理论设计了双圆弧谐波齿轮装置，并对其结构性能、接触特性以及动力学等方面的分析，探索相关规律，为后续在结构优化、增强啮合性能提供了一定的理论依据。 论文主要包括以下几方面内容： 1 ...
王萌萌
core
Distribution, scale, and drivers of mass mortality events in Europe's freshwater bivalves
Conservation Biology, EarlyView.Abstract Mass mortality events (MMEs) are decimating populations and compromising key ecosystem functions around the globe. One taxon particularly vulnerable to MMEs is freshwater bivalve mollusks. This group has important ecosystem engineering capacities and includes highly threatened and highly invasive taxa.
Daniel A. Cossey +39 more
wiley +1 more source
Response of stable states of simple marine plankton ecosystems to warming [PDF]
, 2016 温度是影响海洋浮游生态系统结构和功能的关键环境因子。从上个世纪初以来，受到人类排放温室气体的影响，全球海洋平均温度明显升高。但温度影响浮游生态系统变化和浮游生物生物量变动的机制还不明确。本文采用理论模型与实验生态相结合的方法探究温度对简单浮游生态系统稳态的影响，并一同考虑营养盐的输入，得到如下主要结果： 1.建立描绘以亚心形扁藻(PlatymonasSubcordiformis，绿藻)为被捕食者、海洋尖尾藻(Oxyrrhismarina，甲藻 ...
李奕慧
core
考虑谐波谐振和电压稳定的海上风电场无功优化配置方法 [PDF]
, 2023 海上风电经长距离高压交流海底电缆接入电网，海底电缆容升效应显著，容易引起工频过电压，同时电力电子器件和线路电容引起的谐波谐振问题也严重影响着电网电能质量，因此进行海上风电场无功配置时应充分考虑过电压和谐波谐振问题。针对上述问题，建立了海上风电场谐波模型，对海上风电场的谐波模态阻抗进行扫描，继而分析海上风电场的谐振特性；然后研究了海上风电场无功特性，计算各种发电出力水平和并网点电压下的风电场无功缺额；接着以降低综合成本为目标，以静态电压稳定裕度、最小补偿容量、谐波谐振及过电压为约束 ...
杜婉琳*, 梅桂华, 王玲, 马明
core +1 more source
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
wiley +1 more source
An Advanced CAT System and Dynamics Analyses of A Gearbox
Jixie chuandong, 1994 本文首先介绍由美国ＨＰ公司的ＨＰ３５６５５多通道信号采集与分析系统、丹麦Ｂ＆Ｋ公司的激振测量设各和美国ＳＤＲＣ公司的Ｉ—ＤＥＡＳＴｅｓｔ模态分析软件等构成的先进ＣＡＴ系统，然后介绍用它对一台普通齿轮减速箱进行模态试验的过程和模态分析结果。
邹昌平, 黄文振, 梁锡昌
doaj