Results 21 to 30 of about 1,261,710 (147)

Biodiversity‐driven spatial conservation planning to delineate temporally stable regions

open access: yesConservation Biology, Volume 40, Issue 3, June 2026.
Abstract The accelerating loss of biodiversity underscores the critical need for effective conservation strategies, particularly in the face of climate change and anthropogenic pressures. We devised a conservation planning framework that adopts a temporal stacking approach to species distribution models and landscape connectivity analyses. These models
Mattia Iannella   +5 more
wiley   +1 more source

社会认知与老化:问题、观点和方法

open access: yes, 1999
以往认知与老化的研究为我们描述了一幅悲观的景象〔1,2〕,即随着增龄老年人的认知功能逐渐减退。70年代开始,由于毕生发展理论中获得与丧失观点的提出,认知老化的研究更多地转向功能与适应的方向〔3,4〕,目前这方面研究较多的是老年人的社会认知和日常问题解..
李川云, 吴振云
core   +1 more source

复合绝缘子HTV硅橡胶材料老化特性的研究

open access: yesGaoya dianqi, 2013
针对在役复合绝缘子的老化问题,笔者分别对实验室电晕老化和现场自然老化的HTV硅橡胶材料的憎水性、泄漏电流、表面微观形貌以及化学成分等特性进行了对比研究。结果表明,电晕老化与现场老化造成材料特性变化的规律呈现一致性:电晕老化造成材料憎水性下降,且提高电晕老化强度(电压和时间)则导致憎水性恢复变慢,甚至不能完全恢复;现场老化材料的憎水性随年限不断下降,由HC1级(2年)降至HC5级(15年)。老化还造成样品的表面电阻率下降,引起表面泄漏电流增加;老化造成硅橡胶材料降解,表面缺陷增加,孔洞增加并加深 ...
申文伟   +6 more
doaj  

Internal physiological drivers of leaf development in trees: Understanding the relationship between non‐structural carbohydrates and leaf phenology

open access: yesFunctional Ecology, Volume 40, Issue 5, Page 1151-1164, May 2026.
Read the free Plain Language Summary for this article on the Journal blog. Abstract Plant phenology is crucial for understanding plant growth and climate feedback. It affects canopy structure, surface albedo, and carbon and water fluxes. While the influence of environmental factors on phenology is well‐documented, the role of plant intrinsic factors ...
Yunpeng Luo   +8 more
wiley   +1 more source

基于红外光谱和憎水性的运行复合绝缘子老化特性

open access: yesDianci bileiqi, 2019
复合绝缘子广泛应用于输电线路中,运行年限也越来越久,长期挂网运行的复合绝缘子同时受到运行环境和自然条件的影响,致使复合绝缘子老化问题越来越受到人们的关注。选取不同运行年限的110kV复合绝缘子作为研究对象,通过对伞裙材料进行憎水性测试和红光光谱分析,研究复合绝缘子老化特性及老化机理。结果表明:复合绝缘子沿串伞裙老化呈非均匀性分布,两端伞裙表面老化严重,中间位置伞裙老化程度较轻。上伞面老化严重,下伞面老化较轻;伞裙内侧较外侧老化严重。
王晨晖, 蒋濛, 姚龙
doaj  

Social protection in fragile and conflict affected settings: The case of Sudan

open access: yesInternational Social Security Review, Volume 79, Issue 2, Page 17-42, April/June 2026.
Abstract This article examines Sudan’s state‐led social protection system by conducting a mapping of the country’s main social protection schemes, drawing on legislative documents and secondary reports as well as the 2022 Sudan Labor Market Panel Survey.
Dáire Brady, Zina Nimeh
wiley   +1 more source

自由基清除剂对电老化聚乙烯中空间电荷的影响

open access: yesGaoya dianqi, 2004
向低密度聚乙烯中添加自由基清除剂能够有效地抑制电老化,因而改变了电老化过程中聚乙烯的空间电荷的分布。在直流预压和短路过程中,空间电荷量随老化时间呈线性增长。结合自由基清除剂在其它老化形式中的化学反应机理,详细讨论了自由基清除剂对聚乙烯电老化的抑制以及老化过程中空间电荷分布的影响。
李喆, 尹毅, 肖登明
doaj  

How Changing Narratives About the Future Shape Policymaking for the Long Term

open access: yesEuropean Policy Analysis, Volume 12, Issue 2, Spring 2026.
ABSTRACT How can we explain decisions by governments to engage in policy investments—accepting short‐term costs in return for anticipated gains in the longer term—after previously sustaining the status quo? Our article examines the role of narratives in changing expectations about the future as a key driver of intertemporal policymaking. In light of an
Pieter Tuytens, Charlotte Haberstroh
wiley   +1 more source

First Confirmed Cooperative Breeding of the Brown Hornbill (Anorrhinus austeni) in China at the Sino–Lao Frontier 中国中老边境尚勇保护区首次记录白喉犀鸟 (Anorrhinus austeni) 的合作繁殖行为

open access: yesIntegrative Conservation, Volume 5, Issue 1, Page 10-15, March 2026.
First confirmed breeding of the Brown Hornbill in China, documented through cooperative feeding in Shangyong Protected Area. ABSTRACT The Brown Hornbill (Anorrhinus austeni), a Near Threatened frugivore, reaches the northern edge of its distribution in southern Yunnan, China, yet breeding had not been previously documented with site‐attributed nests in
Junsong Li   +8 more
wiley   +1 more source

认知老化机制的研究

open access: yes, 2000
认知老化机制的研究, 主要包括两个方面: (1) 年龄差异及其影响因素的研究; (2) 变异性研究。介绍了以系统整体观为指导的柏林老化研究 (BASE)和美国MacArthur成功的老化研究, 老化变异性研究既涉及工作记忆、加工建构、自我效能等, 心理因素, 也涉及社会、经济和生理因素。最后提出今后认知老化机制的研究应加强学科间协作和充分利用新的理论与方法 ...
李川云, 吴振云
core   +1 more source

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