Results 1 to 10 of about 1,362 (65)
Jianzhu Gangjiegou Jinzhan, 2021 风电机组大型化逐渐成为我国中东部、南部等低风速区风电塔的发展趋势。单机容量大型化带来的机头极限荷载和疲劳荷载的提升,给传统风电单管式钢塔筒支撑结构的设计、制造和运输带来了巨大挑战。为解决此问题,提出了一种构架式预应力抗疲劳钢管风电塔,在降低支撑结构用钢量、提升结构刚度避免共振的同时,通过在塔柱钢管内张拉预应力钢绞线的方式,降低塔柱焊接节点所受疲劳外荷载应力幅的平均应力,从而延长其疲劳寿命,并改善疲劳脆性破坏特性。基于上述预应力抗疲劳构架塔概念,通过整理总结相关规范和标准的规定以及文献研究结论 ...
罗宇骁, 马人乐, 裘科一
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Research on dynamic properties of a cable-truss pre-stressed dome(索-桁预应力穹顶结构的动力性能研究)
Zhejiang Daxue xuebao. Lixue ban, 2003 索-桁结构是一种有潜力的空间结构,但目前的研究尚不够深入.本文提出了一种圆形平面索-桁预应力结构,采用反应谱法和时程法分析,研究了其动力性能.结果表明,该种结构的频谱极为密集,振型较为复杂;这类结构采用反应谱法计算动内力将导致不可接受的误差,而应采用相应的时程分析法计算动内力.同时还得出了这种结构预应力的施加不可缺少,否则将有可能导致动力破坏的结论.
GAOBo-qing(高博青) +1 more
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Functional Ecology, EarlyView.Read the free Plain Language Summary for this article on the Journal blog. Abstract The stoichiometric ratios of carbon (C), nitrogen (N) and phosphorus (P) serve as important indicators for assessing nutrient balance in forest ecosystems, but their relationships with photosynthetic dynamics require deeper characterization.
Minghao Chen +9 more
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Functional Ecology, EarlyView.Read the free Plain Language Summary for this article on the Journal blog. Abstract Soil organic nitrogen (SON) transformation is critical for global nutrient cycling and ecosystem productivity, yet how its responsiveness to climate change differs across diverse land use types remains poorly resolved.
Xinyi Yang +10 more
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Conservation 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
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Advancing conservation breeding programs for marine invertebrates
Conservation Biology, EarlyView.Abstract In the face of ecosystem change and biodiversity loss caused by climate change and other stressors, conservation breeding, or captive breeding, with the aim of reintroduction for wild population recovery, is an emerging tool for preventing species’ extinction and rehabilitating ecosystems.
Elora H. López‐Nandam +3 more
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Gaoya 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
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Insights for conservation from the Ecological Knowledge Games project
Conservation Biology, EarlyView.Abstract Environmental conservation research requires robust methods for collecting large‐scale behavioral data and engaging diverse stakeholders in decision‐making processes. We (Y.P., A.B.D., and N.B.) created EcoKnowGames (Ecological Knowledge Games), a transdisciplinary project that develops knowledge games for conservation science and data ...
Yuan Pan +4 more
wiley +1 more source
Scientists’ warning on the global destruction of rock outcrop ecosystems
Conservation Biology, EarlyView.Abstract Rock outcrops are geological formations that harbor a highly specialized biota adapted to harsh environmental conditions that differ from their surrounding landscapes. They are globally distributed, especially in old, highly weathered landscapes, and can function as habitat islands containing high levels of endemism and distinct evolutionary ...
Luiza F. A. de Paula +19 more
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Jianzhu 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
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