Results 21 to 30 of about 18,258 (182)
Jellyfish blooms restructure plankton dynamics and trophic linkages in coastal waters
Functional Ecology, EarlyView.Read the free Plain Language Summary for this article on the Journal blog. Abstract Jellyfish blooms are increasing globally in frequency and intensity, introducing complex ecological interactions, yet the mechanisms by which they alter ecosystem structure remain poorly characterized due to a lack of sustained field observations.
Pengpeng Wang +4 more
wiley +1 more source
Gaoya dianqi, 2017 针对在设计真空断路器弹簧操动机构凸轮轮廓线的过程中,依靠经验或者反复试验的方法设计出的凸轮轮廓线存在无法准确匹配负载特性的缺陷,采用一种负反馈优化设计方法。首先,根据负载特性推导出动力特性;其次,通过动力特性倒推出凸轮转角,进而计算出凸轮轮廓线;然后,根据凸轮呈现的合闸动力特性再次验证并修正负载特性,保证分合闸速度;最终,通过设计验证证明了使用该方法设计的凸轮能够使得动力特性准确匹配负载特性,并保证断路器可靠合闸。
赵玉芝 +5 more
doaj
Conservation Biology, EarlyView.Abstract Prioritization in conservation is crucial for the development of efficient and effective decision‐making policies. For many decades, the importance of some species and their habitats has been assessed and applied in conservation legislation, but bats and their diurnal roosts have ofbeen overlooked.
David López‐Bosch +6 more
wiley +1 more source
Gaoya dianqi, 2022 电磁斥力机构由于其分闸速度快，分闸时间短和分闸时间分散性低等优势，配备于快速真空开关，可极大地压缩电网故障的切除时间，当前受到了众多研究者的关注。文中的目的是研究配于快速真空开关的电磁斥力机构的暂态动力学特性。文中提出了一种新型的全耦合仿真方法，该方法耦合了柔体动力学模块、外电路模块、运动方程、多体动力学模块、瞬变电磁场和疲劳分析模块的求解过程，可对电磁斥力机构的暂态动力学特性进行全面评估。通过仿真计算了各零部件在分合闸过程中的速度、行程曲线、放电电流、洛伦兹力和应力应变等动态特性 ...
王蕾 +7 more
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Experimental study of dynamic behavior of Huqiu pagoda [PDF]
, 2005 The dynamic behavior is an important index to evaluate the seismic property and damage of ancient pagodas. Combining with the research of protection technology on Huqiu pagoda, this paper discusses the key points, schemes, and measures of improving test ...
CHEN Han-bin +4 more
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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
Jianzhu Gangjiegou Jinzhan, 2010 拉索的动力特性是拉索性能分析的基础。考虑抗弯刚度和支承弹性等因素建立拉索动力分析模型,研究了拉索的动力特性。本文研究表明:抗弯刚度和支承弹性变形对拉索自振频率影响都较大;支承弹性变形对奇数阶频率的影响远大于对偶数阶频率的影响;当反映索弹性支承刚度大小的无量纲参数k>25时,认为索两端固定,可不考虑支承弹性变形对拉索动力特性的影响。
郝坤超, 魏金波, 李国强
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Gaoya dianqi, 2023 高压自能式SF6断路器单向阀、回气阀和泄压阀的运动特性对灭弧室气流场计算结果的准确性具有重要影响。基于3个阀片实际的运动规律，运用牛顿第二定律，建立阀片运动的数学模型，并结合真实气体物性参数，对自能式SF6断路器灭弧室冷态气流场进行仿真，准确获得了3个阀片的运动特性，同时分析了3个阀片的受力特性及阀片周围的压力分布。研究表明，空载情况下，单向阀将对拉杆产生相对运动，这是引起单向阀由闭合到开启状态变化的主要原因，而回气阀移动的主要原因是压气室压力的建立 ...
赵伟涛 +4 more
doaj
Representation of obligate groundwater‐dwelling copepod diversity in European protected areas
Conservation Biology, EarlyView.Abstract Groundwaters sustain diverse surface ecosystems and are populated by metazoan species, mostly invertebrates, that provide fundamental ecological functions and are often of prominent conservation value due to narrow endemism and high phylogenetic rarity.
Francesco Cerasoli +7 more
wiley +1 more source
Conservation Biology, EarlyView.Abstract In the western United States, conservation practitioners are increasingly working with private landowners to restore habitat for North American beavers (Castor canadensis) and to use nonlethal mitigation techniques when beavers damage crops and infrastructure.
Brian D. Erickson, Megan S. Jones
wiley +1 more source