Results 11 to 20 of about 21,128 (118)
Shuitu Baochi Xuebao, 2022 为探究野外实际调查中常见的含结构体工程堆积体土壤侵蚀过程，设计含结构体工程堆积体和对照组2种试验材料（对照组为不含结构体工程堆积体，后文中对2种试验材料简称为结构体和堆积体），通过室内模拟降雨试验，研究了结构体和堆积体坡面径流侵蚀特征与雨强和场次的关系。结果表明：（1）初产历时随雨强和场次的增加而减小，结构体对初产历时有延缓作用，这与结构体的土壤特性和下垫面特征有关；（2）平均径流率和平均流速均随雨强和场次的增加而增大，堆积体平均流速和平均径流率分别是结构体的1.11~1.22，1.11~1.37倍 ...
李镇 +4 more
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考虑土壤电阻率分布各向异性的高压直流接地极均流电阻配置方法及试验验证
Gaoya dianqi, 2021 在高压直流接地极工程中,加装均流电阻是改善地表电位分布,降低极址跨步电压的一种有效手段。然而,由于土壤电阻率分布的复杂性和各向差异性,采用理想的水平分层模型计算配置直流接地极的均流电阻往往存在较大的误差。针对此问题,文中提出了一种基于接地极特性参数实测值的均流电阻配置方法。该方法通过实际测量接地极极环各段的分流比例、接地电阻、互阻、自跨步电压系数、互跨步电压系数等参数,以此作为输入条件,将各段的跨步电压相等作为控制目标,计算获得均流电阻的配置方案。最后通过一个缩比接地极模型 ...
谭波 +6 more
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Shuitu Baochi Xuebao, 2020 通过野外径流小区人工降雨试验，研究坡形和聚丙烯酰胺（PAM）对径流量、土壤侵蚀和养分流失的影响。试验设置2个PAM施用量，分别为0，2 mg/L；9种坡形处理，即4个凹形坡，4个凸形坡，1个直形坡。结果表明：（1）与均匀坡面相比，凸形坡的平均土壤流失量、氨氮流失量和磷酸盐流失量分别增加25.12%，24.01%和26.96%，且土壤和养分流失量随着凸形坡面的凸度增加而增加，凹形坡的平均土壤流失量、氨氮流失量和磷酸盐流失量分别减小13.53%，10.85%和19.95%；（2 ...
邢伟民 +4 more
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Wildlife Letters, EarlyView.The study explores how beavers (Castor spp.) affect endangered freshwater pearl mussels (Margaritifera margaritifera) in European rivers. Beaver dams can harm small, fragmented mussel populations by reducing flow, increasing sediment, and potentially limiting host fish movement, while larger populations may benefit from improved bed stability and ...
Louise Lavictoire +2 more
wiley +1 more source
Emerging applications of large language models in ecology and conservation science
Conservation Biology, EarlyView.Abstract Large language models (LLMs) mark a major development in artificial intelligence, with potentially transformative implications for ecology and conservation science. Built on advanced deep‐learning architectures, these models can support a wide range of tasks. We reviewed emerging applications of LLMs, drawing on the wider scientific literature
Christos Mammides +5 more
wiley +1 more source
Evaluating the use of taxonomy in the IUCN Red List
Conservation Biology, EarlyView.Abstract Taxonomy defines the units that conservationists strive to preserve for future generations. However, the discovery of new species and the taxonomic revision of existing species affect conservation efforts. Despite the importance of taxonomy for a species’ conservation, there is currently no overview of how those leading species extinction risk
Stephen T. Garnett +8 more
wiley +1 more source
Gaoya dianqi, 2023 均压电极是高压直流输电工程换流阀内冷水系统的重要部件，起到钳制电势和减小泄漏电流的关键作用，但是在运行过程中，均压电极发生腐蚀或者断裂，将导致换流阀阀塔上与内冷水管道接触的金属器件发生腐蚀，内冷水系统发生渗漏、堵塞等，从而使得换流站因设备过热、水管漏水等问题造成的停运事件屡有发生，严重影响直流工程的安全稳定运行。因此，研究均压电极断裂相关机理和原因能够有效减小内冷水系统事故。文中通过分析均压电极在水管内的受力情况，结合铂金材料的特性，首次从剪切强度的角度开展了均压电极断裂分析。文中从材料成分、力学性能 ...
肖凯 +5 more
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Conservation Biology, EarlyView.Abstract Modeling species distributions in dynamic pelagic environments remains challenging, particularly for wide‐ranging and highly mobile species when there is limited guidance on model performance. This limitation constrains the effective use of species distribution models (SDMs) in marine conservation, where robust and transferable predictions are
E. Pasanisi +32 more
wiley +1 more source
International Journal of Applied Linguistics, EarlyView.ABSTRACT Collaborative writing has attracted increasing attention in English as a Foreign Language (EFL) instruction due to its potential to enhance learners’ writing competence. However, few studies have examined the comparative effects of collaborative versus independent writing on EFL learners’ individual performance, especially in higher‐order ...
Ting Huang, Chenze Wu, Wenkang Zhang
wiley +1 more source
Gaoya dianqi, 2023 随着当今时代电力电子技术的发展，SiC MOSFET在高频、高温、高压以及大电流等场合中得到广泛应用，然而，由多管并联所导致的不均流问题成为了当下SiC MOSFET模块广泛应用中的一大阻碍。针对这一问题，文中提出一种基于动态栅电阻的SiC MOSFET模块并联均流方法，其主要原理是通过利用SiC MOSFET开关瞬间漏极电流在源极寄生电感上感应出的电压来检测电流，并通过动态调节栅极驱动电阻来实现并联模块的电流同步。最后，通过利用多脉冲实验对文中所提出的均流策略的可行性及优势进行了实验验证。结果表明 ...
张瑜, 田鸿昌, 文阳
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