Results 21 to 30 of about 5,045 (166)

Study on Geochemistry of Nutrient and Nutrient Criteria in Jiulong Estuary [PDF]

open access: yes, 2015
由于大量的人为输入河口的营养盐(特别是氮和磷),近海富营养化区域逐渐扩大。河口和近海水体的富营养化已经引起了全世界的广泛关注。水体富营养化对环境造成很多影响,比如水质恶化、赤潮爆发、生态系统结构改变、低氧和死亡区的出现以及大量的经济损失。研究河口营养盐循环,并建立合理的营养盐基准值保护河口及沿海水体的措施刻不容缓。 本研究融合多学科知识,对不同季节的九龙江河口地区进行了多个航次的现场采样和同位素培养,运用GIS技术并收集整理历史数据,揭示了九龙江河口营养盐时空变化、内部迁移转化过程以及水体营养盐浓度 ...
黄铮
core  

Ultrafast Catalytic Decomposition Reaction Using a ZIF‐67@Cellulose Nanofiber Composite‐Based Cobalt/ Nitrogen Co‐Doped Nanoporous Carbon for Water Treatment

open access: yesRare Metals, Volume 45, Issue 3, March 2026.
ABSTRACT Recently, cobalt/nitrogen co‐doped materials have emerged as heterogeneous catalysts to activate peroxymonosulfate (PMS) and have been applied to advanced oxidation processes for environmental remediation. However, their recyclability and reusability remain major barriers to practical application.
Wen‐Kai Zhu   +11 more
wiley   +1 more source

脲醛缓释肥不同配比对小麦生长及土壤氮素养分的影响

open access: yesShuitu Baochi Xuebao, 2017
在黄淮海地区冬小麦中高产田采用小区试验,以普通尿素基施、普通尿素基施加追施作对比,研究脲醛氮占总氮30%,40%,50%,60%,70%的不同脲醛缓释掺混肥在田间的氮素养分释放特征,以及对土壤氮素养分、小麦产量、氮素利用率及经济效益的影响,探明合理施用脲醛缓释肥最优氮素配比,以达到增加产量、节约资源、增加经济效益的目的。结果表明:脲醛掺混肥氮素释放量在小麦生育进程中呈现高低再高低的变化过程,脲醛氮占总氮40%或50%最有利于土壤氮素供应,脲醛氮所占比例过大或过小,都不利于小麦整个生长期氮素供应 ...
周华敏   +5 more
doaj  

Genetic analysis and gene mapping of panicle branches stay-green trait in rice [PDF]

open access: yes, 2016
水稻是重要的粮食作物之一,全球一半以上的人口以大米为主食。随着世界人口的增长,人们正面临着越来越严重的粮食危机。如何增加水稻产量一直是作物育种以及植物学研究的重要目标。近年来水稻遗传育种工作者发现了一些成熟期叶片的叶绿素不降解或仅少量降解而使叶片仍保持绿色的持绿型水稻品种,研究发现其叶片持绿性状多数属多基因控制的数量遗传,少数属隐性主效基因控制的质量性状遗传,相关基因大多已被鉴定及克隆。迄今为止,尚未见穗枝梗持绿性状的研究报道。佳辐占系本课题组育成的优质高产早稻品种,已在生产上大面积推广应用 ...
王永杰
core  

Synergistic Effect of MOF@CMC‐Derived Magnetic Nanocomposites: Enhancing Electromagnetic Interference Shielding and Joule Heating

open access: yesRare Metals, Volume 45, Issue 3, March 2026.
ABSTRACT Emerging as attractive alternatives for sustainable, low‐cost, and high‐performance electromagnetic interference (EMI) shielding, biomass‐derived carbon is nonetheless constrained by a limited repertoire of shielding mechanisms. Herein, a straightforward method was employed to synthesize self‐supporting Co nanoparticles embedded in porous N ...
Yingjie Xu   +6 more
wiley   +1 more source

Fabricating Highly Efficient Ternary Mn–CeOx/Co3O4 Catalysts for Low Temperature Thermal Desorption of Persistent Perfluorooctanoic Acid in Soil

open access: yesRare Metals, Volume 45, Issue 1, January 2026.
ABSTRACT Developing efficient catalytic thermal desorption systems is of great significance in the field of sustainable soil remediation. Herein, novel Mn–Ce solid solution modified Co3O4 nanocrystals were successfully prepared for the removal of perfluorooctanoic acid (PFOA) in soil.
Yu‐Hao Liu   +8 more
wiley   +1 more source

基于15N同位素示踪盐渍化农田向日葵氮素利用规律

open access: yesShuitu Baochi Xuebao, 2022
为探明盐渍化农田不同施氮水平下向日葵氮素吸收利用规律,采用15N同位素示踪技术进行田间微区试验,以不施氮处理(N0)为对照,设计3种施氮水平(N1=150 kg/hm2、N2=225 kg/hm2、N3=300 kg/hm2),于向日葵成熟期测定植株和0—100 cm土层土壤15N同位素丰度及总氮含量,研究各处理肥料氮素的去向及其利用机制。结果表明:向日葵氮素吸收量随施氮量的增加而增加,成熟期作物氮素吸收量在N2水平较不施氮显著增加38.7%;土壤氮和肥料氮对作物当季氮素吸收的贡献比例为84.9%和15.
乔天, 刘霞, 杨威, 高宏远
doaj  

四川冬水田的历史变迁 [PDF]

open access: yes, 2014
四川冬水田的发展史大致可分为清代的兴起与扩展,民国的继承与发展,新中国的改造与缩减三大阶段。水稻种植规模的大小、劳动生产率的高低、水利设施的多少均是影响冬水田发展的因素之一。以往提高农业产出的是改造冬水田的动因;现今提倡恢复冬水田又是出于其水利、生态湿地价值的考虑。冬水田作为一项大规模的水利工程,其之于四川农业 ...
陈桂权
core  

Nitrogen Anchoring Effect Triggering Improved Reversible Hydrogen Storage of Mg(BH4)2

open access: yesRare Metals, Volume 45, Issue 1, January 2026.
ABSTRACT This research uncovered the influence of nitrogen‐doped MXene Ti3CN on the reversible hydrogen storage properties of Mg(BH4)2. The Mg(BH4)2‐20Ti3CN composite began releasing hydrogen at a temperature of 80°C. In addition, the composite discharged over 8.8 wt% hydrogen at a comparatively lower temperature of 270°C, whereas the pure Mg(BH4)2 ...
Zhen‐Xuan Ma   +7 more
wiley   +1 more source

Home - About - Disclaimer - Privacy