Results 11 to 20 of about 1,350,451 (215)
应用VanGenuchten提出的土壤水分特征曲线公式,推导出了沙漠风沙非饱和土壤水分特征曲线的分形模型。通过对古尔班通古特沙漠地9种不同土壤样本利用中子水分仪和负压计实测的水分特征曲线资料反求得到相应的分形维数,分析了分形维数与土壤质地之间的关系,结果表明随着土壤质地从流动风沙土、半固定风沙土到固定风沙土的变化,其分形维数呈逐渐增大。此外,基于土壤颗粒的重量与粒径分布求出了古尔班通古特沙漠地风沙土壤粒径的分形维数。通过对土壤水分特征曲线的分形维数与土壤粒径的分形维数的对比 ...
苏里坦 宋郁东 张展羽
doaj +1 more source
本文根据刚塑性最小加速度原理 ,建立了在非对称爆炸冲击载荷作用下自由圆柱壳体的分析模型 ,在不同辅助装药分位角和变形初速条件下 ,用该模型分别计算了相应的壳体最终变形。模拟实验表明 ...
陈放, 王鹏, 马晓青
core +2 more sources
American ginseng is a shade‐obligate, North American medicinal plant that is widely traded and used internationally. To meet global demand, ginseng is cultivated in forest farms in the Appalachian region of the USA and field‐based artificial shade farms in two regions: Ontario, Canada and Wisconsin, USA. We conducted social research leveraging in‐depth
Rachel E. Palkovitz +2 more
wiley +1 more source
在所建立的载流条形薄板的非线性磁弹性基本方程——运动方程、几何方程、物理方程和电动力学方程的基础上,通过变量代换,整理成含有10个基本未知函数的标准柯西型方程。采用差分及准线性化方法,将含有10个基本未知函数的偏微分方程组,变换成能用离散正交法编程求解的准线性微分方程组。由此计算分析两边简支条形薄板在电磁场和机械载荷耦合作用下的应力与变形 ...
白象忠, 田振国, 边宇虹
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The effect of air pollution on plants is still underexplored, especially belowground. We used a field facility that released diesel exhaust and ozone at concentrations equivalent to those near a busy road in Reading, UK, to measure belowground gas exchange of Scots pine together with feeding by large pine weevils, a major pest of conifers.
Tihomir Simin +7 more
wiley +1 more source
Abstract Written as a letter to my 28‐year‐old self, this paper explores the development of my engagement with cultural complexes. On August 18, 2009, I finished a chapter applying cultural complexes to a history of China, complete with elaborate charts that seemed to confirm a process by which cultural complexes are formed, and how China’s then recent
Kevin Lu
wiley +1 more source
The collective application of shorebird tracking data to conservation
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
Institutional lessons from the Nordic management model
Abstract To improve wildlife management outcomes, in terms of reaching management goals and increasing legitimacy, Nordic countries have developed institutional systems involving stakeholders that aim for a more inclusive and participatory model.
Jens Nilsson +2 more
wiley +1 more source
Morphological character evolution of Amorphophallus (Araceae) based on a combined phylogenetic analysis of trnL, rbcL, and LEAFY second intron sequences [PDF]
Sequences of three different genes in 69 taxa of Amorphophallus were combined to reconstruct the molecular phylogeny of this species-rich Aroid genus.
Gravendeel, B. +3 more
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Subspecies taxonomy reflects social and geographic patterns of taxonomic effort in tetrapods
Abstract Subspecies have been used in conservation biology to account for intraspecific patterns in genetic diversity, which is crucial to long‐term population viability. Although over 3200 subspecies are currently assessed by the International Union for Conservation of Nature Red List, their biological relevance remains controversial.
Jhonny J. M. Guedes +3 more
wiley +1 more source

