نتایج جستجو برای: chemical nitrogen

تعداد نتایج: 485517  

Journal: :The journal of physical chemistry. B 2015
Zheng-Hua He Jun Chen Guang-Fu Ji Li-Min Liu Wen-Jun Zhu Qiang Wu

Despite extensive efforts on studying the decomposition mechanism of HMX under extreme condition, an intrinsic understanding of mechanical and chemical response processes, inducing the initial chemical reaction, is not yet achieved. In this work, the microscopic dynamic response and initial decomposition of β-HMX with (1 0 0) surface and molecular vacancy under shock condition, were explored by...

2007
Iain Fraser Carly Stevens

Current levels of nitrogen deposition, especially ammonia, seriously impact upon ecosystems biological diversity. However, land use policy maintaining and enhancing key ecosystems in the UK in most cases does not explicitly take account of this pollution in terms of onsite management prescriptions. In this paper the economic potential of agricultural land retirement to reduce localised nitrogen...

Journal: :Biomedical and environmental sciences : BES 2006
G Tripathi B M Sharma

OBJECTIVE To study the impacts of abundance of woodlice, termites, and mites on some functional aspects of soil in order to elucidate the specific role of soil fauna in improving soil fertility in desert. METHODS Fauna-rich sites were selected as experimental sites and adjacent areas were taken as control. Soil samples were collected from both sites. Soil respiration was measured at both site...

Journal: :Nature communications 2016
Thomas Spatzal Julia Schlesier Eva-Maria Burger Daniel Sippel Limei Zhang Susana L A Andrade Douglas C Rees Oliver Einsle

The [Mo:7Fe:9S:C] iron-molybdenum cofactor (FeMoco) of nitrogenase is the largest known metal cluster and catalyses the 6-electron reduction of dinitrogen to ammonium in biological nitrogen fixation. Only recently its atomic structure was clarified, while its reactivity and electronic structure remain under debate. Here we show that for its resting S=3/2 state the common iron oxidation state as...

Journal: Desert 2020
H. Azarnivand, H.R. Naseri, M. Jafari, M.A. Zare chahoki Sh. Yousefi Khanghah

Rangelands are very diverse, and they spread from low vegetation desert areas to those with more rainfall and more cover In saline and desert areas, there are many restrictions on vegetation establishment, hence the use of amendments. The study area is located south of Nazarabad city in Alborz province, Iran. In this study, different amendments, such as mineral biochar, arbuscular mycorrhiza fu...

Journal: :health scope 0
reza barati roshvanlo department of environmental health, tarbiat modares university, tehran, ir iran abass rezaee department of environmental health, tarbiat modares university, tehran, ir iran; department of environmental health, tarbiat modares university, tehran, ir iran. tel/ fax: +98-2182883575 hooshyar hossini department of environmental health, tarbiat modares university, tehran, ir iran mohamad shiri department of environmental health, tarbiat modares university, tehran, ir iran

conclusions based on nitrification and denitrification data, the best condition for nitrifying/ denitrifying performance was obtained by modified-ifas. hence, the modification can be used to obtain the best activities of microbial and nitrogen removal improvement. results employing the bet, surface area (sa), total pore volume (vp), and average size of the nanostructure were 0.4026 m2/g, 3.8089...

2016
H. García-Gómez J. L. Garrido M. G. Vivanco L. Lassaletta I. Rabago G. Sánchez I. González-Fernández R. Alonso

Evidences of an ongoing nitrogen enrichment of Spanish terrestrial ecosystems have been recently recorded. Atmospheric chemical transport models are valuable tools to identify those areas where these effects of atmospheric nitrogen deposition could be occurring. This study documents the performance of two chemical transport models (EMEP and CHIMERE) in predicting annual values of wet deposition...

Journal: :American journal of botany 2012
Mary A Jamieson Timothy R Seastedt M Deane Bowers

UNLABELLED PREMISE OF THE STUDY Human nitrogen (N) inputs to terrestrial ecosystems have greatly increased in recent years and may have important consequences for plant growth, reproduction, and defense. Although numerous studies have investigated the effects of nitrogen addition on plants, few have examined both above- and belowground responses within a range of predicted increase and apart...

2013
E. C. Browne R. C. Cohen

In contrast with the textbook view of remote chemistry where HNO3 formation is the primary sink of nitrogen oxides, recent theoretical analyses show that formation of RONO2 (6ANs) from isoprene and other terpene precursors is the primary net chemical loss of nitrogen oxides over the remote continents where the concentration of nitrogen oxides is low. This then increases the prominence of questi...

2015
Franziska Bandau Vicki Huizu Guo Decker Michael J. Gundale Benedicte Riber Albrectsen Jian Liu

Plant intraspecific variability has been proposed as a key mechanism by which plants adapt to environmental change. In boreal forests where nitrogen availability is strongly limited, nitrogen addition happens indirectly through atmospheric N deposition and directly through industrial forest fertilization. These anthropogenic inputs of N have numerous environmental consequences, including shifts...

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