Results 21 to 30 of about 29,284 (225)

Global overview of progress in respecting the contributions of traditional knowledge in biodiversity governance

open access: yesConservation Biology, EarlyView.
Abstract Recognition and engagement of Indigenous Peoples and local communities (IP&LCs) and other traditional knowledge (TK) holders in formal biodiversity governance remain limited, despite their significant contribution to the conservation and sustainable use of biodiversity through their knowledge, innovations, practices, and land stewardship.
Kinga Öllerer   +8 more
wiley   +1 more source

Study on Corner-Fed Cavity-Backed Slot Dual-Polarized Antennas [PDF]

open access: yes, 2015
为了在2.4GHz频段WLAN中实现具有方向性辐射的MIMO技术,采用背腔环形缝隙结构辐射元,通过倒置正交微带线激励,设计具有一定方向性的正交双极化天线结构。为提高端口间的隔离度和辐射场的极化纯度,在馈线正对的另一侧共面加载尺寸完全一致的接地或不接地导体带条。在此基础上,采用角馈的方法以期进一步改善天线的性能,并对各种可能天线形态进行对比分析。具体内容如下。 (1)对于边馈情形(即馈线位置垂直平分矩形导体腔表面的直角边),可以发现,没有加载导体条时,较佳隔离度对应的频带要高于阻抗工作频带,且相隔距离较大。
谢昇
core  

Effects of political identity activation and inaccurate metaperceptions on attitudes toward wolves

open access: yesConservation Biology, EarlyView.
Abstract Polarization between groups can undermine durable conservation outcomes. Activating group identities (i.e., an individual's sense of self derived from membership in a group) can exacerbate differences, especially when people hold inaccurate perceptions of their peers and rivals.
Alexander L. Metcalf, Justin W. Angle
wiley   +1 more source

Research of Retrieving Sea Surface Wind Vectors Based on Sentinel-1A Satellite SAR Images [PDF]

open access: yes, 2016
海面风场是海气交互界面的重要物理参数,与海洋中绝大多数的海水运动密切相关。海面风场还是海气相互作用的重要媒介,调节了海水和大气之间的物质以及能量输送,对全球气候调节也有着十分重要的作用。 船舶、浮标等观测手段花费高昂,加上海洋面积巨大,可获得的现场海面风场数据十分有限,很难满足大面积海面风场的观测需求。日益发展的卫星遥感技术,为大面积观测风场提供了可能,微波散射计已经成为大面积获取全球海面风场的最重要遥感手段之一,不过微波散射计的空间分辨率通常为25-50km,难以满足对高分辨风场的需求 ...
毕上上
core  

Geographic risks to functional groups of mammals and birds from habitat loss in Mexico

open access: yesConservation Biology, EarlyView.
Abstract There is a need to quantify the impact of habitat loss due to anthropogenic factors on different aspects of biodiversity, such as functional trait diversity represented by functional groups (FGs). We developed a metric to assess the weighted risk of loss of habitat for 33 FGs of mammals and 36 FGs of birds in Mexico based on potential ...
Fernando Mayani‐Parás   +4 more
wiley   +1 more source

基于扩展Debye模型仿真的回复电压特征量分析

open access: yesGaoya dianqi, 2017
回复电压测量方法(return voltage measurement,RVM)能有效检测变压器固体绝缘的含水量,然而对于含有局部峰值点的回复电压极化谱难以给出明确的诊断结论。文中在扩展Debye模型基础上,仿真分析了模型参数变化对极化谱和主时间常数CTC、回复电压峰值最大值Urmax的影响规律,并提出将扩展Debye模型不同时间常数支路数作为新的特征量,最后验证了该特征量的可行性。仿真和试验结果表明:RVM极化谱前、中、尾3部分分别对应着油纸绝缘变压器油中偶极子转向极化 ...
吴广宁, 宋臻杰, 辛东立
doaj  

Electro-optic modulation of AlGaN in deep ultraviolet [PDF]

open access: yes, 2016
深紫外非线性光学材料在光信息处理和高速光通讯等领域具有广泛的应用前景,发展适宜工作在深紫外波段的新型非线性光学材料成为国际学术界和产业界研发的热点。AlGaN基半导体凭借宽带隙带来的信道容量大、纤锌矿晶格排列缺乏反演对称性造成的非线性光学效应、以及作为半导体可控制对n型p型的光电集成等优势,成为理想的深紫外波段非线性光学材料,在电光调制和电光开关等非线性光学器件方面极具应用潜力。本文理论设计并生长了高Al组分的AlxGa1-xN/GaN超晶格结构,通过椭圆偏振光谱表征测算AlxGa1-xN ...
吴小璇
core  

Calibration of the species threat abatement and restoration metric's threat abatement component in a Costa Rican landscape

open access: yesConservation Biology, EarlyView.
Abstract Achieving global conservation policy goals requires the ability to set and measure progress toward science‐based targets for biodiversity. The species threat abatement and restoration (STAR) metric was developed to enable actors to set science‐based targets for species.
Louise Mair   +17 more
wiley   +1 more source

Effects of Treponema pallidum on THP-1 derived macrophage polarization [PDF]

open access: yes, 2015
梅毒螺旋体(Treponemapallidum)是性传播疾病梅毒的致病菌,尽管有关T.pallidum的研究已经开展近一个多世纪,对其生物学及病原学特性有了一定的了解,然而对于T.pallidum致病机制的认识还处于起步阶段。巨噬细胞作为机体防御外来病原体的第一道防线,在对T.pallidum的识别、吞噬、抗原提呈、杀伤等方面均发挥着重要作用。随着对巨噬细胞研究不断深入,有学者将巨噬细胞分为两种不同的极化类型,即促进炎症发展的M1型巨噬细胞和在抑制炎症反应及组织修复等方面发挥作用的M2型巨噬细胞 ...
席亚
core  

Scenarios and strategies for future‐proofing ecosystem management under climatic novelty

open access: yesConservation Biology, EarlyView.
Abstract Climate change is driving unprecedented declines in dominant, habitat‐forming foundation species across marine and terrestrial ecosystems globally. As climatic novelty becomes the norm, ecosystem reassembly will become increasingly common. Predicting and understanding these transitions, and their implications for future ecosystem functioning ...
Lauren T. Toth   +14 more
wiley   +1 more source

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