Results 21 to 30 of about 1,016,161 (161)
How much biotic nativeness matters across human demographic groups
Abstract Many central concepts of conservation biology—such as nativeness—are structured by ecological and social factors. However, the social consequences of using these concepts to make conservation decisions remain inadequately understood. Some researchers argue that nativeness, rather than acting as an objective proxy for important ecological ...
Harold N. Eyster, Rachelle K. Gould
wiley +1 more source
Informing spatial conservation prioritization with species’ traits
Abstract New Guinea, the most botanically diverse island on the planet, is the location for one of the boldest conservation initiatives. The Manokwari Declaration aims to achieve 70% conservation designation for the Bird's Head Peninsula. This is 40% higher than the 2022 Global Biodiversity Framework target.
Liam A. Trethowan +27 more
wiley +1 more source
为了系统地研究杆件初弯曲对半刚接单层柱面网壳稳定承载力的影响,对5种矢跨比的半刚接网壳进行了双重非线性全过程分析。首先阐述了焊接球节点刚度及随机杆件初弯曲的确定方法,然后深入研究了杆件初弯曲对5种矢跨比的半刚接网壳稳定承载力的影响程度,最后探讨了具有杆件弯曲的半刚接网壳的破坏过程。研究结果表明,杆件初弯曲对半刚接网壳稳定承载力的影响程度与网壳矢跨比和初弯曲分布形式有关。如杆件初弯曲对矢跨比为1/3、1/4半刚接网壳的影响甚微,对矢跨比为1/5半刚接网壳的影响较为明显。矢跨比为1 ...
肖姚, 李会军
doaj
接触网-受电弓系统是列车运行驱动力的来源。相比于柔性接触网,刚性接触网因其净空低、坚固耐用、抗风性好等优点一直是当前研究的热点。针对刚性接触网悬挂结构的传统建模方法是将其等效成弹簧结构,并根据能量守恒对其刚度进行等效。基于此,提出一种基于遗传算法的利用刚性接触网的实验模态信息识别建模参数的新方法,建立刚性接触网仿真模型新的验证和修改方法,设计若干常见工况对本方法的可行性进行验证。研究结果表明:本方法因其对结构刚度的敏感性,不仅可识别刚性接触网悬挂结构刚度,而且当悬挂结构损伤时 ...
张玲芳 +4 more
core
Abstract There exists a growing suite of technologies that support significant and exciting progress in biodiversity conservation and research. Citizen scientist participation is common in this research and often focuses on data collection and labeling.
Joycelyn Longdon +5 more
wiley +1 more source
Changes in Key Biodiversity Area networks following national comprehensive assessments
Making comprehensive assessments of Key Biodiversity Area (KBA) networks in a country greatly increases their number and area. Countries that have not yet done so will be missing about half of these globally significant sites and missing the opportunity to get 30 × 30 conservation in the right places. Abstract Key Biodiversity Areas (KBAs) are sites of
Andrew J. Plumptre +46 more
wiley +1 more source
针对采用半刚性节点连接的双肢冷弯薄壁C形钢框架,采用拟静力试验与有限元模拟相结合的方法,对9榀双层单跨框架进行抗震性能分析。分析了节点螺栓直径、节点板厚度、螺栓间距及节点板加腋大小等参数对框架抗震性能的影响。结果表明:增大螺栓直径、增加节点板厚度和节点板加腋均能提高框架的承载力,改善框架的抗震性能。当螺栓间距小于80mm时,框架的承载力及抗震性能随间距的增大而增大;当螺栓间距大于80mm时,承载力及抗震性能受其影响较小。使用8.8级M16高强度螺栓,框架节点板产生了较大的滑移 ...
陈明, 陈亚栋
core +1 more source
Vulnerability of tropical fish communities across depth in the central Indian Ocean
Abstract Coral reefs and their fish communities below scuba diving depth (>30 m), in mesophotic coral ecosystems (MCEs) (∼30–150 m), in rariphotic (150–300 m), and in upper bathyal waters (300–500 m) are often underexplored, especially in the Indian Ocean.
Paris V. Stefanoudis +12 more
wiley +1 more source
The configurational transition of polyelectrolyte chain confined in a cylinder(聚电解质链在柱状受限下的构象转变)
采用粗粒化分子动力学模拟方法,研究了受限于圆柱体内的聚电解质链的构象行为。通过计算链平均回旋半径、平均持久长度和平均形状因子等物理量,重点探究反离子价态、链刚性和受限孔径等对聚电解质链尺寸和构象转变的影响。结果表明,受限聚电解质链可形成稳定的棒状、球状、折叠链状和环状结构。尤其在三价反离子诱导下,半刚性聚电解质链可形成稳定的环状结构,并由切向相关函数表征。通过统计反离子分布,进一步探讨了聚电解质链和离子凝结的机制。同时讨论了环的成核和生长动力学特征 ...
高菊先(GAO Juxian) +2 more
doaj +1 more source
Evaluating protected areas’ coverage of threats to terrestrial biodiversity
Abstract Protected areas (PAs) are vital for biodiversity conservation and have expanded globally. However, increasing pressures on biodiversity make it difficult to achieve conservation goals. Using threat probability maps based on the International Union for Conservation of Nature Red List and the World Database of Protected Areas, we analyzed the ...
Katherine Pulido‐Chadid +2 more
wiley +1 more source

