Results 11 to 20 of about 5,045 (166)

Nitrogen Transports and Transformations in Mangrove Sediments using Nitrogen Isotope Techniques in China [PDF]

open access: yes, 2012
人类活动对生态系统的影响日益扩大,过量施肥、化石燃料的燃烧等引发的氮(N)负荷迅速增加。陆地生态系统过剩的N通过流域汇集至河口和海岸,威胁着海洋生态系统的健康。目前,全球N循环正致力于揭示河口和海岸地区N的源汇格局及主导机制。红树林湿地广泛分布于热带、亚热带河口和海岸地区,作为陆源营养盐入海过渡带,在缓解陆源N输入方面扮演着重要角色,成为了研究的热点。 本研究利用N稳定同位素技术,将现场培养与室内模拟培养相结合,揭示了我国东南沿海典型河口和海湾红树林湿地沉积物总氮沉积、固氮作用、反硝化作用 ...
李颖
core  

Designing 3d Transition‐Metal Doped g‐C3N4 Monolayer for Enhanced Bifunctional Oxygen Evolution/Reduction Reactions Activity: Defect Physics and Constant‐Potential Study

open access: yesRare Metals, Volume 45, Issue 4, April 2026.
ABSTRACT Graphitic carbon nitride (g‐C3N4) doped with 3d transition metals (3d‐TM@g‐C3N4) has gained attention as a noble metal‐free alternative for oxygen evolution and reduction reactions (OER/ORR). Yet the key mechanisms driving its performance remain debated, especially across different charge states.
Jing Zhang   +6 more
wiley   +1 more source

The Effect of N2O Emission Mitigation by Growing Soybeans Instead of Other Crops [PDF]

open access: yes, 2016
农业是重要的温室气体排放源之一,而在农业生产过程中施用氮肥是引起农业温室气体排放的主要原因。因此,如何合理有效的施用氮肥对减少农业温室气体排放、减缓全球气候变化至关重要。鉴于此,对通过合理施用氮肥从而减少温室气体排放的减排措施进行成本效益分析,将有助于我们找到具有经济效益的农业温室气体减排方法。目前,相关减排措施研究主要集中在农田测土配方施肥、改良施肥(缓释肥和长效肥)上。得益于与豆类作物共生的根瘤菌具有的固氮作用,豆类作物相比其他农作物施用更少的氮肥,从而排放更少的氧化亚氮(N2O)。因此 ...
许俊武
core  

Biomass‐Engineered Defect‐Rich g‐C3N4 Anchors Pd2+‐Rich Ultrafine Particles for Highly Efficient Formic Acid Dehydrogenation

open access: yesRare Metals, Volume 45, Issue 4, April 2026.
ABSTRACT Formic acid (FA) is considered to be a safe and convenient hydrogen source; however, achieving controlled and efficient FA dehydrogenation under mild conditions using stable solid catalysts remains a significant challenge. Pd‐based catalysts have been extensively studied due to their superior catalytic activity to other metal catalysts.
Shuai Wei   +10 more
wiley   +1 more source

Gradient distributions of nitrogen and organic carbon in the soils from inland to tidal flat in the Yellow River Delta [PDF]

open access: yes, 2014
黄河三角洲是我国典型的通过黄河冲积泥沙填海造陆形成的近代沉积区。区域受到黄河冲积、沉积等自然过程和农业耕种熟化等人类活动的双重影响。本研究通过在黄河三角洲地区内陆到河口海湾不同距离采集典型土壤类型剖面发生层样品,探讨土壤有机碳、总氮等生源要素的空间分布规律,为阐明我国典型海岸带地区陆源碳、氮的输送及循环特征提供基础依据。研究结果表明,黄河三角洲内陆与河口地区呈现出完全不同的土壤碳、氮分布规律。表层土壤碳、氮含量在黄河沿岸及三角洲南部均表现出由陆向海逐级递减的空间分布特征 ...
李远   +4 more
core   +1 more source

Bimetallic NiCo Loaded on the Nitrogen‐Rich Modified Lignin‐Derived Carbon Coordination Network for Accelerated Oxygen Reduction Kinetics

open access: yesRare Metals, Volume 45, Issue 4, April 2026.
ABSTRACT The development of novel oxygen electrocatalysts with cost‐effectiveness, scalability, high catalytic activity, and stability presents a significant challenge for zinc–air batteries (ZABs). The nitrogen‐rich lignin coordination network structure is synthesized through amine modification of lignin.
Ping‐Xian Feng   +8 more
wiley   +1 more source

Elevation, soil pH and calcium availability shape regional and local scale spatial patterns of PhoD gene abundance in tropical and subtropical forests

open access: yesFunctional Ecology, Volume 40, Issue 4, Page 983-1000, April 2026.
Read the free Plain Language Summary for this article on the Journal blog. Abstract Organic phosphorus mineralization is a critical process in the phosphorus cycle, governing phosphorus bioavailability for plants. The PhoD gene, which encodes the key enzyme alkaline phosphatase, serves as a valuable biomarker for this process.
Sandhya Mishra   +3 more
wiley   +1 more source

小麦氮素营养与籽粒灌浆期氮素转移的研究进展

open access: yesShuitu Baochi Xuebao, 2004
对小麦氮素营养与籽粒灌浆期氮素转移研究进展进行了综述。过去进行的大量研究结果表明,小麦籽粒最终累积的氮素有相当一部分来自于灌浆期间营养器官中氮素的再转移,来自营养器官氮(内源氮)与土壤中新吸收氮(外源氮)的比例基本上是1:2。因此,花后营养器官氮素营养水平是决定小麦籽粒产量、籽粒中氮素累积量和蛋白质含量的一个重要因素。灌浆期间营养器官氮素向籽粒发生转移的同时,常常伴随着叶片光合性能的下降和叶片的衰老。不同基因型品种在灌浆期的氮素转移程度不同,表现为随品种演替,旗叶、茎秆和叶鞘中氮素的输出率增加 ...
李世清 王瑞军 张兴昌 伍维模 邵明安
doaj   +2 more sources

Study on the nitrogen removal process and influencing factors in the rhizosphere of Sesuvium portulacastrum floating bed [PDF]

open access: yes, 2016
大气是地球氮元素储量最大的氮库,由于氮气的三键结构十分稳定,打开它所需的能量较高,因此在工业革命以前,主要靠闪电固氮和生物固氮将其转化为人和生物可以利用的含氮化合物。然而随着人类社会的不断发展,为了满足人们生产生活的需要,大量氮元素被通过工业的方式固定下来,并随着化肥的滥用积累在环境中,造成氮循环的破坏,并产生水体富营养化现象。富营养化带来的恶果就是水体藻类大量繁殖,溶解氧急剧降低,造成鱼虾等水生生物的死亡等。因此,想要根除富营养化现象就必须将水体过量的氮、磷营养盐从水体脱除 ...
仇元
core  

Electronic Modulation of CoNi Nanoparticles by N‐Doped Carbon for Efficient Lignin Hydrogenolysis to Aromatic Monomers

open access: yesRare Metals, Volume 45, Issue 3, March 2026.
ABSTRACT Cost‐effective and efficient non‐noble‐metal catalysts for selective lignin hydrogenolysis remain elusive, representing a significant challenge in biorefinery. Here, we prepared a nitrogen‐doped carbon supported CoNi bimetallic catalyst, which was successfully derived from zeolitic imidazolate framework (ZIF) via high‐temperature pyrolysis ...
Xingwei Luo   +3 more
wiley   +1 more source

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