Results 21 to 30 of about 1,009,107 (167)

From pollen provision to pollinator: Species‐specific sterol assimilation by wild bees in urban landscapes

open access: yesFunctional Ecology, Volume 40, Issue 6, Page 1906-1920, June 2026.
Read the free Plain Language Summary for this article on the Journal blog. Abstract Human‐driven landscape change, particularly urbanization, is reshaping pollinator communities, yet the functional traits that mediate species persistence remain poorly understood. Dietary specialization is commonly used to predict species vulnerability.
Yan Yang   +5 more
wiley   +1 more source

800kV GIS高压开关设备抗震性能分析

open access: yesGaoya dianqi, 2015
笔者以800 kV GIS(gas insulated switchgear)高压开关设备的抗震性能为研究对象,采用模态分析理论对设备进行动力特性分析,得到了结构自振频率和振型。分别利用反应谱理论和时程分析理论对结构进行地震动特性分析。通过反应谱分析和输入天津波、EI-Centro波、taft波的动力时程分析,讨论了这两种分析方法结果上的一致性与局限性。并根据几种不同地震波对高压开关设备的不同影响,得出相对于taft波振幅和持时较小的天津波对设备产生破坏作用最大;经过对频率调整,具有相同幅值的两种EI ...
林莘, 李丹, 徐建源
doaj  

Information Processing and Changes to Local Governments' Practices Amid Intensifying Environmental Hazards

open access: yesReview of Policy Research, Volume 43, Issue 3, May 2026.
ABSTRACT Information processing is a fundamental part of policy making and is all the more critical in modern policy making environments characterized by information abundance. Using Punctuated Equilibrium Theory (PET) as a lens, this study investigates how city governments process and apply externally generated knowledge to address environmental ...
Rachel M. Krause   +4 more
wiley   +1 more source

高频感应放电的理论分析 [PDF]

open access: yes, 1981
本文利用拟渠道模型得到简明的分析表达式,求出了放电特性曲线;定义了高频振荡器的输出特性曲线,并作了计算;且由槽路参数将上述两曲线联系起来,定出工作点。为此可预先对任一种气体及高频机判断放电能否维持;可以讨论对工程实践至关重要的阻抗匹配问题以及功率放大规律 ...
陈允明
core  

分频提取的定时抖动

open access: yes, 1986
本文提出了一种适合于140Mb/s数字复接设备中定时抖动分析的方法——分频提取抖动分析法。此方法较为全面地考虑了影响抖动的各种因素,在较为一般的情况下 ...
王建利
core   +1 more source

Cohen类时频分布比较及其在局部放电信号处理中的应用

open access: yesGaoya dianqi, 2010
系统地以参函数的角度介绍了6种典型的Cohen类时频分布。从理论和应用效果上分析了各分布的交叉干扰项衰减和时频分辨率性能。针对局部放电信号的非平稳性,展现了各分布在处理仿真和实际脉冲信号的应用效果。试验结果表明,平滑伪Choi-Williams分布(SPCWD)对局放脉冲非平稳信号引发的短时变化具有高度的敏感性,更为适合表征局放脉冲信号的时变信息。据此,可提取单个脉冲波形的时频特征参数、分析多个连续放电脉冲的时频变化,从而用于放电类型的模式识别以及深入研究绝缘系统中的局部放电机理。
何平   +5 more
doaj  

The Role of Political Ideology in Shaping South Korea's Foreign Policy and Its Implications

open access: yesAsian Politics &Policy, Volume 18, Issue 2, April 2026.
ABSTRACT South Korea's foreign policy toward its neighbors frequently shifts when there is a leadership change from one ideological group to another. For instance, when power shifts from progressives to conservatives, South Korea's relations with the United States and Japan tend to improve while its ties with China and North Korea deteriorates.
Alec Chung
wiley   +1 more source

基于线调频小波变换能量谱的电机故障信号处理

open access: yesGaoya dianqi, 2005
提出了一种基于高斯线调频小波变换诊断电机故障的新方法。线调频小波变换是信号的时间-频率-尺度变换, 具有比小波变换及其它时频分析更强的非平稳信号分析功能。利用高斯线调频小波变换作电机故障信号的能量谱估计,可提取电机故障信号的频率成份。试验结果表明,这种方法比Fourier变换和小波变换频率分布的能量更集中。
胡国胜, 朱锋峰, 任震, 涂用军
doaj  

Distribution, scale, and drivers of mass mortality events in Europe's freshwater bivalves

open access: yesConservation Biology, Volume 40, Issue 2, April 2026.
Abstract Mass mortality events (MMEs) are decimating populations and compromising key ecosystem functions around the globe. One taxon particularly vulnerable to MMEs is freshwater bivalve mollusks. This group has important ecosystem engineering capacities and includes highly threatened and highly invasive taxa.
Daniel A. Cossey   +39 more
wiley   +1 more source

Automating the analysis of public saliency and attitudes toward biodiversity from digital media

open access: yesConservation Biology, Volume 40, Issue 2, April 2026.
Abstract Measuring public attitudes toward wildlife provides crucial insights into human relationships with nature and helps monitor progress toward Global Biodiversity Framework targets. Yet, conducting such assessments at a global scale presents challenges.
Noah Giebink   +8 more
wiley   +1 more source

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