Results 11 to 20 of about 1,713,702 (163)

男性生殖衰老特征的多角度认识 [PDF]

open access: yesZhongshan Daxue xuebao. Yixue kexue ban, 2022
随着婚育年龄推迟,大龄夫妇生育需求逐渐增加,生殖衰老成为社会发展面临的重要公共卫生问题。研究表明40~55岁可能为男性生育力的“分水岭”。然而,相比女性生殖衰老,男性生殖衰老特征缺乏鲜明特征,对机体的复杂影响表现为多方面。本篇综述中,我们从男性生殖内分泌、生殖腺,以及生殖附属性腺的衰老性变化角度,阐述对男性生殖衰老特征的认识。
李湘平, 邓春华
doaj   +2 more sources

ZnO压敏电阻直流老化特性的研究

open access: yesDianci bileiqi, 2021
ZnO压敏电阻是电子和信息化领域重要的过电压防护器件,对电子与通信系统的运行安全有着至关重要的作用。本研究基于压敏电阻直流老化特性实验平台,开展了热电应力下ZnO压敏电阻温度特性、荷电率特性以及长期直流电压下老化特性的变化规律研究。实验与分析结果证明:1)在电应力与热应力作用下,ZnO压敏电阻的泄漏电流和功率损耗随着荷电率增大而增大;2)同一型号压敏电阻在同温度(115℃),不同荷电率下两组直流老化实验,泄漏电流曲线经历了快速上升、缓慢下降至平稳、激增3个变化阶段,两组老化时间存在较大差异; 3 ...
黄海博, 孙伟, 万翔, 姚学玲
doaj  

Scientists’ warning on the global destruction of rock outcrop ecosystems

open access: yesConservation Biology, EarlyView.
Abstract Rock outcrops are geological formations that harbor a highly specialized biota adapted to harsh environmental conditions that differ from their surrounding landscapes. They are globally distributed, especially in old, highly weathered landscapes, and can function as habitat islands containing high levels of endemism and distinct evolutionary ...
Luiza F. A. de Paula   +19 more
wiley   +1 more source

Linguistic Analyses of Written Corrective Feedback for Chinese as a Second Language: ChatGPT Versus Human Teachers

open access: yesInternational Journal of Applied Linguistics, EarlyView.
ABSTRACT This study conducted linguistic analyses of the written corrective feedback (WCF) for Chinese as a second language (CSL) provided by chat generative pre‐trained transformer (ChatGPT) and human teachers (including preservice teachers and senior teachers).
Ling Zhang   +2 more
wiley   +1 more source

(De)Legitimizing Language Policing: Enregisterment and Linguistic Authority in Taiwan's Digital Public

open access: yesJournal of Sociolinguistics, EarlyView.
ABSTRACT This study investigates how ordinary Taiwanese netizens perform linguistic authority by policing others’ use of Mainland Chinese expressions in everyday online interactions not originally intended to be political and how such policing is subsequently supported, resisted, or (de)legitimized in the context of Taiwan–China relations. Three orders
Hsi‐Yao Su
wiley   +1 more source

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

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

自然老化硅橡胶材料表面憎水性及耐受特性的研究

open access: yesGaoya dianqi, 2009
研究硅橡胶材料的老化特性对于复合绝缘子的设计、选型及维护具有重要意义。以经过现场投样、自然老化后的复合绝缘子伞裙压片为研究对象,详细研究了硅橡胶材料自然老化前后在憎水性迁移特性、憎水性丧失特性、憎水性恢复特性上出现的差异,另外对材料受酸碱侵蚀后表面维持憎水性的能力也进行了研究。结果表明,老化对于材料憎水性能的影响较明显,上下表面由于存在日照、雨淋、积污和冲刷等因素的差异,老化程度不同,上表面的憎水性能表现的更差一些。
贺博   +4 more
doaj  

室温硫化硅橡胶绝缘保护材料冷热循环老化特性研究

open access: yesGaoya dianqi, 2020
为探究工作在气温条件多变、昼夜温差大的环境下室温硫化硅橡胶(RTV)绝缘保护材料的老化特性,文中制备了RTV硅橡胶试样,并对其进行了冷热循环老化模拟试验,通过红外光谱测试(FTIR)及扫描电子显微镜(SEM)研究了老化前后微观结构的变化规律及老化机理,并通过拉伸试验、介电性能测试及击穿试验,分析了冷热循环老化过程中力学性能、体积电阻率、介电性能及击穿强度等宏观特性的变化规律。结果表明,冷热循环老化过程中,试样分子链交联网络劣化,同时产生-OH等强极性基团。在老化温度及高低交变温度应力共同作用下 ...
金海云   +6 more
doaj  

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

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