Results 21 to 30 of about 37,717 (232)
Functional Ecology, EarlyView.Read the free Plain Language Summary for this article on the Journal blog. Abstract Decomposition is the transformation of dead organic matter into its inorganic constituents. In most biomes, decomposition rates can be accurately predicted with simple mathematical models, but these models have long under‐predicted decomposition in globally extensive ...
Heather L. Throop +8 more
wiley +1 more source
Shuitu 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
A DFT Study on C-H Bond Activation of Methane by CeO2 and CeO2-doped with Metal Cations [PDF]
, 2015 甲烷是天然气的主要成分，是燃料和化学品中非常出色的原材料，但甲烷又是非常稳定的分子，其活化常需较高的温度，因此，研究有效活化甲烷，特别是较低温下转化甲烷的催化剂，具有理论和实际的研究意义。近年来，研究表明二氧化铈基纳米催化剂具有良好的低温活化甲烷性能，但其活性中心本质和活化机理尚不很清楚。为此，我们采用密度泛函理论(DFT)方法，对二氧化铈及掺杂不同金属阳离子的二氧化铈体系活化甲烷C-H进行了计算研究。其主要研究内容和结果如下： 1.以(CeO2)m(m=1-3)团簇为模型对甲烷C ...
陈蓉芳
core
Functional Ecology, EarlyView.Read the free Plain Language Summary for this article on the Journal blog. Abstract Root exudates play a key role as signals and nutrients in mediating plant–microbe communication. However, critical knowledge gaps remain regarding how root exudates mediate soil–microbe–plant interactions to regulate crop yield under long‐term straw mulching combined ...
Jiajie Song +7 more
wiley +1 more source
Turn Structure, Chirality Transfer and Applications of Peptide-Based N-Amidothioureas [PDF]
, 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
Functional Ecology, EarlyView.Read the free Plain Language Summary for this article on the Journal blog. Abstract Human‐driven landscape change, particularly urbanization, is reshaping pollinator communities, yet the functional traits that mediate species persistence remain poorly understood. Dietary specialization is commonly used to predict species vulnerability.
Yan Yang +5 more
wiley +1 more source
Dianci 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
Functional Ecology, EarlyView.Read the free Plain Language Summary for this article on the Journal blog. Abstract Ecological communities are stressed by rapid and complex anthropogenic changes, threatening the persistence of biotic interactions and ecosystem functioning. Plant–pollinator communities, for instance, undergo structural transformations as a result of land‐use change ...
Erliang Gao +8 more
wiley +1 more source
Gaoya 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
Functional Ecology, EarlyView.Read the free Plain Language Summary for this article on the Journal blog. Abstract Most terrestrial plant species form symbioses with arbuscular mycorrhizal fungi (AMF). However, the below‐ground carbon (C) allocation of plants and the nutritional and growth benefits provided by AMF within this symbiosis vary greatly across species and environments ...
Hengjun Zhao +3 more
wiley +1 more source