Results 21 to 30 of about 1,038 (114)
Shuitu Baochi Xuebao, 2003 比较研究了南亚热带鼎湖山森林群落演替序列中马尾松林、针阔混交林和季风常绿阔叶林表层(0～20cm)土壤pH值、有机质、全N、速效K、交换性Ca和Mg、有效P、B、Mo、Cu、Fe、Zn和易还原Mn等营养元素的含量及其相关关系,结果表明:马尾松林土壤pH值显著高于其它两森林土壤;随着群落的进展演替,养分在土壤中的累积(Ca除外)呈不断增加的趋势 ...
欧阳学军 黄忠良 周国逸 褚国伟 李炯 史军辉 徐国良
doaj +2 more sources
Gaoya dianqi, 2019 高压断路器是电力系统的核心设备,其稳定可靠运行具有重要意义。高压断路器分合闸电流曲线能够很大程度上反映高压断路器分合闸机构的运行状态,因此文中研究了在几种典型故障条件下,断路器分合闸线圈电流的变化。随机森林算法由于算法实现过程中的两次随机过程,使得算法过拟合风险大大降低,模型泛化能力大大增强。提出了使用随机森林算法识别故障电流曲线,取得了很好的效果。
刘芹 +9 more
doaj
广东电网遭台风泰利侵袭的输配电设备受损分析及评估 [PDF]
全球能源互联网近年来致灾台风频率呈增加趋势，以2023年影响广东电网约百万用户的第4号台风“泰利”为例，分析广东电网遭台风侵袭受灾情况，建立输配电杆塔受损预测模型，识别关键特征变量与因素，为电网防灾减灾提供支持。首先，分析台风“泰利”气象特征，具有“台前对流活跃，风力强度大，降水范围广”等特点，对输配电设备均产生一定程度破坏。其次，利用随机森林、支持向量机、梯度决策树、神经网络等4种机器学习算法建立输配电杆塔受损预测模型，并对比部分算法针对不平衡样本优化前后模型表现。算例表明，随机森林优化后提升最大 ...
侯慧 +5 more
doaj +1 more source
Integrative Conservation, Volume 4, Issue 4, Page 641-651, December 2025.Key Largo woodrats are a small and endangered island species, whose individuals tend to occur in family groups. Isolation from mainland populations, predation, and habitat fragmentation have caused genetic drift, leading to low overall diversity. Here, we found that a major category 4 hurricane promoted genetic diversity in the Key Largo woodrat ...
Taylor Ackley +5 more
wiley +1 more source
World Medical &Health Policy, Volume 17, Issue 4, Page 823-830, December 2025.ABSTRACT Sepsis is a leading cause of mortality in the United States, with over 350,000 deaths annually, yet the contribution of neighborhood‐level social determinants of health (SDoH) remains underexplored. We conducted a retrospective analysis of 4.4 million hospitalized patients with sepsis, identified using ICD‐10 codes, leveraging de‐identified ...
Ahad Khaleghi Ardabili +3 more
wiley +1 more source
Gongye shui chuli, 2023 造纸法烟草薄片废水的COD高且波动大，采用传统国标检测方法（重铬酸钾比色法）操作复杂、耗时长，难以实现快速检测以指导污水处理工况的及时调整。针对此问题，提出了一种基于机器学习的COD快速预测方法。在对烟草薄片废水水质指标分析基础上，采用数理统计结合人工智能的方法对废水COD与悬浮物、pH、溶解氧和电导率等水质参数之间的关系进行分析，并建立COD预测模型。结果表明，线性回归、多项式拟合、正则化回归、回归树等模型的R2为0.656~0.777，基于机器学习的极端随机森林模型的R2最高，为0.861 ...
戴泽军 +5 more
doaj
Finding floral and faunal species richness optima among active fire regimes
Conservation Biology, Volume 39, Issue 6, December 2025.Abstract Changing fire regimes have important implications for biodiversity and challenge traditional conservation approaches that rely on historical conditions as proxies for ecological integrity. This historical‐centric approach becomes increasingly tenuous under climate change, necessitating direct tests of environmental impacts on biodiversity.
Zachary L. Steel +8 more
wiley +1 more source
Conservation Biology, Volume 39, Issue 6, December 2025.Abstract Forest cover is positively associated with fish biomass and fisheries yield in the Amazon River floodplain, and many species enter flooded forests to feed, spawn, or seek refuge from predation. Floating macrophyte beds, known as floating meadows, in Amazon floodplains support high fish diversity and serve as nursery habitat for many fishes of ...
Sam Grinstead +6 more
wiley +1 more source
Shuitu Baochi Xuebao, 2018 采用土壤颗粒分级方法，以湘中丘陵区地域相邻、环境条件基本一致的4种林地：檵木—南烛—满山红灌草丛（LVR）、檵木—杉木—白栎灌木林（LCQ）、马尾松—石栎—檵木针阔混交林（PLL）和石栎－红淡比－青冈常绿阔叶林（LAG）为对象，研究土壤有机碳（SOC）及不同粒径土壤颗粒有机碳含量随着林地退化的变化特征，剖析林地退化对中亚热带森林SOC库的影响机制。结果表明：随着林地退化，>2 μm砂粉粒百分含量增高 ...
王娜 +4 more
doaj
Functional Ecology, Volume 39, Issue 9, Page 2327-2341, September 2025.Read the free Plain Language Summary for this article on the Journal blog. Abstract While elevational patterns of soil bacterial and fungal communities in mountain ecosystems have been well documented, the assembly processes of soil archaeal and protistan communities, and their linkage with ecosystem multifunctionality (EMF), remain poorly understood ...
Bao‐Min Yao +14 more
wiley +1 more source