Results 21 to 30 of about 43,544 (260)

Growing Demand and Uneven Supply: Eight Years of Nature Education in China 需求增长与供给不均:中国自然教育八年发展回顾

open access: yesIntegrative Conservation, EarlyView.
ABSTRACT This study examines the role of nature education in advancing conservation and sustainability in China between 2014 and 2023. Drawing on national survey reports and historical–comparative methods, it analyses the dynamics of public demand, institutional supply, and practitioner capacity.
Qi Yunxi, Lyu Xiang, Huang Yu
wiley   +1 more source

籽粒苋-烟草间作对烟叶部分矿质元素含量及品质的影响

open access: yesShuitu Baochi Xuebao, 2004
采用大容积土培盆栽方法,研究了籽粒苋与烟草间作对烟叶矿质营养元素含量的影响,结果表明:间作烟叶磷的含量比单作降低了21.25%,而氮、钾和硫分别比单作增加了20.23%,63.86%和13.71%,间作烟叶中钾的含量分别是氮、硫的3.16倍和4.66倍;间作烟叶除铜的含量与单作的差异不显著外,其它微量元素含量与单作的差异均达显著或极显著水平,间作烟叶钼和铁的含量较单作分别增加了49.29%和27.39%;间作烟叶的灰分含量也较单作高7.83%;间作烟叶中砷和铬的含量较单作分别降低了15.65%和12 ...
李廷轩 马国瑞
doaj  

Functional Stability Despite Taxonomic Changes in Mixed‐Species Foraging Flock Participants Along an Elevational Gradient in Knuckles Montane Reserve, Sri Lanka 斯里兰卡纳克斯山地保护区 (Knuckles Montane Reserve) 海拔梯度上混合物种觅食群参与者的功能稳定性与分类变化

open access: yesIntegrative Conservation, EarlyView.
This research reveals the functional stability of mixed species foraging flocks (MSF) and their foraging height change with different taxonomic differences along the elevational gradient at Knuckles Montane Reserve, Sri Lanka. This offers new insights into how MSFs sustain with the elevational gradients supporting the altitudinal shifting species ...
Vimukthi. R. Gunasekeara   +3 more
wiley   +1 more source

配电网保护间隙保护距离的研究

open access: yesDianci bileiqi, 2012
配电网保护间隙在提高线路跳闸重合率和防止架空绝缘导线雷击断线上,取得了较为显著的效果。但在实验中发现相对于避雷器动作时间,保护间隙动作时间和绝缘子动作时间相差不多。从保护间隙和避雷器动作时间不同出发,在分析保护间隙保护距离时考虑了保护间隙闪络时间对保护间隙保护距离的影响。先通过实验确定绝缘子和保护间隙的伏秒特性曲线,然后利用相交法计算出不同等级雷电过电压下保护间隙和绝缘子动作时间,最后根据保护间隙和绝缘子的动作时间差和雷电波在线路上传播的速度计算出不同等级雷电过电压下保护间隙的保护距离 ...
张东   +4 more
doaj  

The Relationship between Government Loans and Outward Foreign Direct Investment: A Comparison between China and Japan [PDF]

open access: yes, 2016
政府贷款援助是中国援助事业的重要组成部分。在“一带一路”战略及企业“走出去”战略的实践中,如何利用政府贷款推进中国企业的对外直接投资是一个重要课题,在此方面,日本政府贷款有着丰富的经验。中日两国政府贷款援助的实施情况各有特色,通过对比中日政府贷款援助的异同点,以其与对外直接投资的关系为落脚点,可以进一步探索中国政府贷款援助机制内在的利与弊。 论文首先分析中日政府贷款本身的异同:具体包括贷款规模、贷款条件、捆绑度、受援国参与度以及项目的监督管理等方面,在此基础上 ...
张博文
core  

Urban adults' engagement in nature education and its interplay with everyday lived experiences: A case study from Shenzhen, China

open access: yesPeople and Nature, EarlyView.
Abstract Currently, scholarship on education to foster connectedness with nature primarily focuses on children. As adults likewise face the disconnection from nature and play a key role in influencing children, it is important to understand how they perceive, engage in, and benefit from relevant programmes.
Xiaoxue Chen, Zuyi Lyu, Junxi Qian
wiley   +1 more source

1000 kV特高压变电站带电作业试验研究

open access: yesGaoya dianqi, 2016
为了确保特高压变电站作业人员和设备的安全,开展了特高压变电站带电作业的最小安全距离和组合间隙的试验研究。通过分析1 000 k V特高压变电站带电检修典型作业工况,针对作业人员与周围带电体、接地体之间构成的空气间隙进行操作冲击试验,获得典型带电作业间隙的放电特性曲线。结合典型作业工况下间隙的放电特性,根据变电站通用设计方案的操作过电压水平,计算得到带电作业最小电气安全距离(分裂软母线相地6.8 m、相间9.1 m,硬管母线相地6.2 m、相间9.0 m),以及构架侧方进出分裂母线的最小组合间隙6.2 m、
肖宾, 刘凯, 陈磊, 吴田, 刘庭
doaj  

Turn Structure, Chirality Transfer and Applications of Peptide-Based N-Amidothioureas [PDF]

open access: yes, 2016
多肽是重要的生命基础物质之一,其作用涉及生命活动的各个环节。多肽具有丰富的手性源,系因其氨基酸结构单元绝大部分为手性的。通过分子内手性传递,单个氨基酸残基的手性可影响整条肽链分子结构及功能,而分子间手性传递则于肽链与底物分子间的特异性识别和结合过程中扮演重要角色,因此多肽及其衍生物的手性传递特征备受重视,对拟肽类药物分子及不对称有机催化剂的设计合成、生物分子间相互作用的研究等具有重要指导意义。 同手性起源是手性科学研究的热点及难题,它作为生命科学领域的重要研究内容而备受关注 ...
严小胜
core  

Surface Sulfate Modification Promoted Excitons Extraction of BiOBr Nanosheets for Efficient 1O2 Photosynthesis and Chlorophenols Dechlorination

open access: yesRare Metals, EarlyView.
ABSTRACT Photocatalytic molecular oxygen (O2) activation provides a sustainable approach to produce singlet oxygen (1O2) for organic contaminants detoxification. However, the charge carriers‐involved pathway usually suffers from unsatisfactory 1O2 production efficiency owing to energy loss caused by photogenerated hole‐mediated superoxide species (•O2−
Yan‐Biao Shi   +8 more
wiley   +1 more source

带电作业人员侵入110kV电缆终端塔间隙方式对套管及应力锥电场分布的影响研究

open access: yesDianci bileiqi, 2022
电缆终端套管是电缆线路的薄弱环节,为了掌握带电作业人员不同侵入电缆终端塔间隙的方式对套管及其应力锥电场分布的影响,根据实际110 kV电缆终端搭建仿真模型,因电缆终端塔和应力锥的尺度差异大采用子模型法来优化计算模型,分析了电缆终端正常运行及带电作业人员处于地电位作业、中间电位作业以及等电位作业3种情况对电缆终端应力锥电场分布的影响。计算结果表明:子模型法在保证计算精度的条件下可以有效减少网格数量和缩短计算时间;应力锥在3种作业方式下的电场变化相对于正常运行时均在3.5%以内 ...
吴田   +4 more
doaj  

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