نتایج جستجو برای: nh3

تعداد نتایج: 6782  

2016
Atsushi Takahashi Tadahiro Fujitani

The present study investigates the decomposition of ammonia (NH3) over Ni and Ru catalysts using a kinetic model based on a reaction mechanism consisting of kinetically important elementary steps. Experimental results obtained over a wide range of reaction conditions were reproduced by the model. Recombinative N2 desorption was the rate-limiting step on the Ru catalyst; whereas, the overall rat...

Journal: :Chemical communications 2014
A G Seel E Zurek A J Ramirez-Cuesta K R Ryan M T J Lodge P P Edwards

The lattice and molecular dynamics for the solid phases of the lowest melting-point metal, Li(NH3)4, are determined by incoherent inelastic neutron scattering. Measurements of internal molecular displacements and distortions of the Li(NH3)4 units have been modelled and assigned using density functional theory calculations for the solid and molecular system. Inelastic neutron scattering measurem...

Journal: :Poultry science 1999
P A Moore T C Daniel D R Edwards

This is a review paper on the effects of aluminum sulfate (alum) on ammonia volatilization and P runoff from poultry litter. Initially, laboratory studies were conducted that showed P solubility could be reduced in poultry litter with Al, Ca, and Fe amendments, indicating that these amendments may reduce P runoff. These results were confirmed in small plot studies in which alum applications to ...

2013
Y. Wang

We use a chemical transport model to examine the change of sulfate-nitrate-ammonium (SNA) aerosols over China due to anthropogenic emission changes of their precursors (SO2, NOx and NH3) from 2000 to 2015. From 2000 to 2006, annual mean SNA concentrations increased by about 60 % over China as a result of the 60 % and 80 % increases in SO2 and NOx emissions. During this period, sulfate is the do...

2004
N. Okai

Metal ions play important roles in chemical and biological systems and its oxidation and reduction processes trigger many catalytic reactions in solution. In these systems, the solvation of metal ions is a key issue to understand the chemical behavior. In order to clarify the microscopic aspect of solvation process under a limited number of solvent molecules, solvated metal ion clusters are con...

2012
Matthew W. Kanan

Materials that catalyze efficient electrochemical N2 fixation would open up the possibility of using an N2/NH3 cycle to store and utilize energy from diffuse renewable sources. In such a cycle, N2 and H2O would be electrolytically transformed to NH3 and O2 in an electrolyzer powered by a renewable electricity source. With existing technologies, NH3 can be utilized in solid oxide fuel cells or c...

2005
Larry C. Purcell Thomas R. Sinclair

This study was conducted on soybean (Glycine max L. Merr.) nodules to determine if exogenous NH3 exerts a controlling influence over nitrogenase activity through changes in nodule gas permeability (P), and if decreasing carbohydrate availability, as a result of low-light treatment, increases the sensitivity of root nodules to NH3. Nodulated root systems of intact plants were exposed to one of s...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه زنجان - دانشکده شیمی 1391

ر این پایان نامه، جزییات سازوکار واکنش های آمونیاک با اوزون ، مولکول اکسیژن ، رادیکال هیدروکسیل و هیدرازین با مولکول اکسیژن از دیدگاه ترمودینامیکی و سینتیکی مورد بحث و بررسی قرار گرفته است. ساختار تمام گونه های شرکت کننده در این واکنش ها با روش محاسباتی dft در سطح b3lyp و mp2 بهینه شده اند. در مرحله ی بعد برای محاسبه دقیق تر انرژی نسبی، ساختارهای بهینه شده با روش (ccsd(t و یا g3b3 محاسبه شدند....

1997
Gregory A. Neyhart Joseph T. Hupp Jeff C. Curtis Cliff J. Timpson Thomas J. Meyer

For the RuIII/II couple in [(bpy)2ClOs(4,4′-bpy)Ru(NH3)5] (bpy ) 2,2′-bipyridine; 4,4′-bpy ) 4,4′bipyridine), E1/2 varies linearly with the donor number (DN) of the solvent with a slope of -26 ( 3 mV/DN unit ranging from nitromethane to dimethyl sulfoxide. For the OsIII/II couple, the variation is -3 ( 1 mV/DN unit. Plots of ∆E1/2 ) E1/2(2) E1/2(1) vs DN (E1/2 is the half wave potential for the...

2000
M. A. Sutton E. Nemitz D. Fowler S. Husted

An integrated field experiment was organized as part of the EC EXAMINE project to quantify surface–atmosphere fluxes of ammonia (NH3). Fluxes of NH3, NH4+ aerosol, HNO3 and HCl were measured using the gradient method with several continuous and batch sampling systems. Within-canopy NH3 was determined to quantify the contribution of leaf cuticles, sub-stomatal apoplastic (intercellular) fluids a...

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