Results 11 to 20 of about 18,303 (165)

From pollen provision to pollinator: Species‐specific sterol assimilation by wild bees in urban landscapes

open access: yesFunctional Ecology, EarlyView.
Read the free Plain Language Summary for this article on the Journal blog. Abstract Human‐driven landscape change, particularly urbanization, is reshaping pollinator communities, yet the functional traits that mediate species persistence remain poorly understood. Dietary specialization is commonly used to predict species vulnerability.
Yan Yang   +5 more
wiley   +1 more source

Synthesizing beaver coexistence messaging with the capability, opportunity, and motivation behavior model

open access: yesConservation 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

An experimental approach to assess the combined effects of multiple stressors on a large vertebrate species

open access: yesConservation Biology, EarlyView.
Abstract The design of experiments to investigate the combined effects of multiple stressors requires exposing target organisms to multiple combinations of stressor doses. Concurrent manipulation of stressors is often infeasible with wildlife, but long‐lasting health effects allow individual health to be used as an integrator of prior stressor exposure.
Enrico Pirotta   +24 more
wiley   +1 more source

导电杆预拉力对换流变套管抗震性能的影响

open access: yesGaoya dianqi, 2022
特高压换流变压器是换流站的关键设备,套管是影响换流变抗震性能的一个重要组件。为评估换流变套管的抗震性能,建立了±800 kV换流变—套管体系的精细化有限元模型,获得了体系的动力特性和地震响应,研究了套管内部导电杆预拉力对套管动力特性和地震响应的影响。结果表明:当套管内导电杆所受预拉力较小时,结构基本振型表现为导电杆的振动,加大预拉力可有效提升套管自振频率;适当增加导电杆预拉力,可以显著减小地震作用下导电杆与套管内壁的相对位移响应,有利于提高套管电气性能,且对套筒应力响应无明显影响 ...
陈星   +5 more
doaj  

Analysis of the influencing parameters of stability for half-through steel arch bridge [PDF]

open access: yes, 2016
以某中承式钢拱桥为研究对象,基于有限元稳定分析理论,采用大型有限元软件ANSYS,对该拱桥的稳定安全系数进行了计算,并从荷载布置方式、拱肋抗弯刚度、主梁抗弯刚度、吊杆刚度等方面,分析了影响该拱桥稳定性的因素,得到了一些有价值的结论。Based on the stability theory of arch bridge,the finite element software ANSYS is used to calculated the stability factor and study the ...
李双全
core  

Experimental and Numerical Simulation Research on Penetration Resistance of Prestressed Reinforced Concrete Structure [PDF]

open access: yes
Prestressed reinforced concrete structures are still the commonly used structural form for containment buildings in large pressurized water reactor nuclear power plants.
LIU Mengsha,  GAO Ge,  JIANG Di
core   +1 more source

Calibration of the species threat abatement and restoration metric's threat abatement component in a Costa Rican landscape

open access: yesConservation Biology, EarlyView.
Abstract Achieving global conservation policy goals requires the ability to set and measure progress toward science‐based targets for biodiversity. The species threat abatement and restoration (STAR) metric was developed to enable actors to set science‐based targets for species.
Louise Mair   +17 more
wiley   +1 more source

Influence of resisted horizontal vibratility and stability ability to the reinforced concrete column by pre-stressing force [PDF]

open access: yes, 2009
针对普通钢筋混凝土柱抵抗水平性能较弱的特点,考虑在柱中布置一定数量的预应力筋并施加有效预应力来改善这一状况。本文对钢筋混凝土柱考虑预应力影响下的抗水平性能、稳定效应以及由此而构建的整体预应力混凝土框架结构的抗水平性能进行分析研究,主要工作及结论如下: (1)基于截面应变协调分析方法,经过分析推导得出钢筋混凝土柱考虑预应力影响下的水平荷载-位移求解公式,为分析钢筋混凝土柱抗水平性能提供了一定的理论依据。 (2)对钢筋混凝土柱考虑预应力影响下抗水平性能进行全过程非线性分析,研究了构件从开裂 ...
黄应江
core  

Biodiversity‐driven spatial conservation planning to delineate temporally stable regions

open access: yesConservation Biology, EarlyView.
Abstract The accelerating loss of biodiversity underscores the critical need for effective conservation strategies, particularly in the face of climate change and anthropogenic pressures. We devised a conservation planning framework that adopts a temporal stacking approach to species distribution models and landscape connectivity analyses. These models
Mattia Iannella   +5 more
wiley   +1 more source

铰接半刚性结构找形与找力分析的非线性有限元方法

open access: yesJianzhu Gangjiegou Jinzhan, 2015
对铰接半刚性结构找形、找力分析,提出一种精确的非线性有限元方法.分两步建立找形与找力分析迭代公式。第1步:基于荷载态节点坐标、预应力态节点坐标及预应力态单元预应力,建立荷载态结构非线性平衡方程,根据矩阵微分理论、Newton切线法概念和边界条件求解荷载态结构非线性平衡方程,从而得到预应力态节点坐标迭代公式;第2步:基于预应力态节点坐标、零态节点坐标和预应力态单元预应力,建立预应力态结构非线性平衡方程,同样根据上述理论和概念以及边界条件求解预应力态结构非线性平衡方程,从而得到零态节点坐标迭代公式 ...
刘树堂
doaj  

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