Results 21 to 30 of about 25,302 (204)
Gaoya dianqi, 2020 针对绿色无毒推进剂航天器火箭发动机真空低温条件下点火困难等问题,提出通过放电产生非平衡等离子体,利用其活化效应改善发动机点火性能。为了研究氢、氧混合气体放电产生的活性粒子的时间演化特性,利用Bolsig+求解器计算得到不同电子碰撞反应能量损失分数随约化场强变化规律;利用ZDplaskin程序包对氢、氧混合气体放电过程进行零维仿真;研究了不同约化场强下混合气体活性粒子随时间变化规律。结果表明,不同约化场强下,氢、氧混合气体中各类电子碰撞反应消耗能量占比不同。约化场强较小的情况下 ...
郑体凯 +4 more
doaj
Impacts of Human Development on Wildlife Use of Corridors in Botswana 人类开发对博茨瓦纳野生动物廊道利用的影响
Integrative Conservation, EarlyView.This study examined the effect of landscape‐scale human impact on wildlife in Botswana. We examined how species use wildlife corridors in two different human‐dominated landscapes. We identified differences in temporal overlap between wildlife and humans across both landscapes, which is fundamental to consider in both current and future conservation ...
Tempe S. F. Adams +3 more
wiley +1 more source
Shuitu Baochi Xuebao, 2011 在我国南方红壤中加入不同的磷活化剂进行培养试验,结果显示:磷活化剂提高了土壤有效磷含量,不同活化剂的活化能力不同。相关分析和通径分析结果表明,磷活化剂的活化能力大小顺序为:低分子有机酸钠钙盐>腐植酸>腐植酸钠>脲基甲酸乙酯;磷活化剂可以提高红壤中的Al-P、Ca-P和Fe-P等无机磷含量,其中Al-P和Ca-P与有效磷均达到极显著水平,而Fe-P作用效果不显著,可以通过影响Al-P和Ca-P来间接影响有效磷,磷活化剂会抑制土壤中O-P的生成。
李杰 +4 more
doaj
Modification of radiation effect on cultured human cells [PDF]
, 1984 Thesis--University of Tsukuba, D.M.S.(A), no. 248, 1984.
Eguchi Kiyomi
core
Tracing change in the public perception of plants: insights from archives and social media in China
PLANTS, PEOPLE, PLANET, EarlyView.As urbanization accelerates, historic gardens serve as vital cultural treasures that offer spiritual and cultural support to the public. This study proposes an innovative approach that merges historical records from the Qing Dynasty with contemporary social media data to explore changes in public perceptions of these gardens.
Dong Xu +4 more
wiley +1 more source
Chemical Synthesis of Lactic Acid from Lignocellulosic Compouds Catalysed by Pb(II) or Al(III)-Sn(II) [PDF]
, 2015 催化转化自然界中含量丰富且可再生的纤维素类生物质资源制备平台化学品有非常重要的意义。尤其是，在非氢条件下将纤维素转化为与其化学组成类似的乳酸，是纤维素转化中最具原子经济效益的路径之一，然而相关的研究尚十分有限。本篇论文研究了氮气氛下，简单金属离子Pb(II)和离子组合Al(III)-Sn(II)催化纤维素及其单体葡萄糖转化为乳酸反应，主要取得以下结果： 研究发现，简单金属离子Pb(II)可有效地催化纤维素及葡萄糖转化制乳酸。氮气氛下，在463K反应6h后，Pb(II)催化球磨纤维素制乳酸的收率高达70 ...
王焱良
core
Conservation Biology, EarlyView.Scaling area‐based conservation, including initiatives led or comanaged by Indigenous Peoples and local communities, is a flagship goal of the Kunming‐Montreal Global Biodiversity Framework. Conservationists often aspire to scale initiatives, but this is rarely achieved in practice. Identifying and addressing factors that limit initiative adoption (i.e.
Thomas Pienkowski +39 more
wiley +1 more source
Conservation Biology, EarlyView.Abstract Measuring area‐based conservation outcomes in tropical forests is challenging due to cryptic human disturbances (e.g., hunting). As a result, comparative studies of management strategies providing quantitative outcomes remain scarce, especially in the Neotropics.
Lucy Perera‐Romero +5 more
wiley +1 more source
Synthesis of Aromatic Amines by Pd / C Catalytic Hydrogenation Aromatic Nitro-compounds [PDF]
, 2015 以5%Pd/C为催化剂,芳香族硝基化合物在温和条件(30℃,H2/0.1 MPa)下还原成芳胺。研究了芳环上的取代基对催化加氢反应的影响。结果表明:对位取代的芳硝基化合物的加氢反应速率为:H>CH3>CO2CH3>CF3>F>OCH3;间位取代芳硝基化合物加氢反应速率为:H>CH3>CF3>F>CO2CH3>OCH3>CN;邻位取代芳硝基化合物加氢反应速率为:H>CF3>CH3>OCH3>F>CO2CH3 ...
兰丽娟 +5 more
core +1 more source
Threats to and management of Natura 2000 protected areas relative to agricultural practices
Conservation Biology, EarlyView.Abstract The Natura 2000 (N2K) network combines biodiversity protection and socioeconomic targets. Human activities, such as agricultural practices, can affect biodiversity in N2K sites in diverse ways. Limiting activities with negative impacts while enforcing land management that supports biodiversity is crucial for effective conservation.
Giorgio Zavattoni +7 more
wiley +1 more source