Results 31 to 40 of about 7,470 (134)
We profiled nutritional and physiological markers in captive sifakas, endangered primates from Madagascar, managed in expansive, non‐native forest enclosures. Variation in many markers reflects freely foraged diets and the energy required to maintain homeostasis under more naturalistic conditions.
Lydia K. Greene +5 more
wiley +1 more source
为了解决变压器差动保护由于励磁涌流而经常误动作的问题,对励磁涌流进行了特征分析,指出当前防止差动保护误动作原理的不足,阐述了利用磁通特性原理区分励磁涌流的方法,分析结果表明,该方法能够可靠地识别变压器内部故障。
岳志刚, 杨国旺, 曲艳华
doaj
为探究同域分布的白颈长尾雉(Syrmaticus ellioti)、白鹇(Lophura nycthemera)和勺鸡(Pucrasia macrolopha)的日活动节律及其季节性差异,2018年1月—2020年12月,在浙江清凉峰国家级自然保护区放置120台红外相机开展野外监测,采用核密度估计和重叠系数对3种雉类进行研究,结果显示:(1)在日活动节律上,3种雉类均为以晨昏活动为主的昼行性动物,全年日活动节律重叠系数均较高,但活动高峰不完全重叠。(2)3种雉类日活动节律季节性变化明显,春 ...
谢培根 +8 more
doaj
ABSTRACT This paper aimed to describe and analyze the factors that shaped the political priority of global neurosurgery from 2015 to 2022. The neurosurgery community formed a movement (that can be described as a global health network) to advocate for the neurosurgical patient to ensure safe, timely, and affordable neurosurgical care for all, and ...
Martina Gonzalez Gomez +3 more
wiley +1 more source
旨在研究变压器区外故障被切除后的暂态过程特性,为变压器差动保护的正确动作提供理论参考。首先从变压器恢复性涌流产生暂态过程进行分析;其次利用了MATLAB中的电力系统模块库(PSB)建立变压器区外故障时恢复性涌流产生的数字仿真模型,并对对恢复性涌流的影响因素和二次谐波进行仿真分析;最后根据仿真结果分析得到变压器恢复性涌流本身不会引起变压器差动保护误动,但是由于变压器各侧的电流互感器暂态特性不一致形成的差流,可能导致差动保护误动的结论。
褚晓锐
doaj
Finding floral and faunal species richness optima among active fire regimes
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
Bright spots for advancing ecological understanding and conservation decision‐making
Abstract A lot can be learned by studying bright spots—defined as unexpected positive outcomes. In fields like public health, education, and oncology, identifying factors behind bright spots reveals previously unknown drivers of success that can be replicated elsewhere.
Holly S. Embke +7 more
wiley +1 more source
文中以特高压直流输电线路保护为对象,分析了国内外实际工程应用中继电保护技术和原理存在的问题。行波保护作为现有特高压直流线路的主保护优势明显,但存在耐过渡电阻能力有限、对采样频率要求高等问题。微分欠压保护作为行波保护的冗余保护,缺点类似行波保护,同时缺乏整定依据等。低电压保护在耐过渡电阻能力方面较强,但其选择性较差,动作速度不够快。电流纵差保护选择性好,但由于受到线路分布电容的影响且动作时间长。文中通过梳理当前特高压直流输电线路继电保护技术进展以及存在的问题,并提出利用边界元件、特征频率 ...
李振兴 +4 more
doaj
为了解甘肃白水江国家级自然保护区周边社区人兽冲突现状,为自然保护区解决人兽冲突提供建议,2021年在白水江国家级自然保护区内开展周边社区人兽冲突情况调查。结果显示:野猪(Sus scrofa)和亚洲黑熊(Ursus thibetanus)是保护区内人兽冲突涉及的主要野生动物;玉米(Zea mays)是最常被破坏的农作物;还发生多起野生动物造成人身伤害的安全。在防护措施上,主要以社区居民的围网和警示性伪装物驱赶为主,防护效果较差。相关补偿政策由于资金缺乏大部分不能落实,影响了保护成效和自发保护的积极性 ...
乔明, 侯平, 黄建
doaj
Abstract This study examined the role of maternal mind‐mindedness (MM) – the tendency to ascribe mental states to one's child – in infant regulatory symptoms and disorders and the moderating role of parenting stress and global psychological distress. A better understanding of these relationships may inform prevention and intervention programs.
Anna Katharina Georg +4 more
wiley +1 more source

