Nitrogen oxide (NO) conversion to ammonia (NH3) over iron oxide clusters is investigated using density functional theory calculations. The introduction of NO and H2 over gas-phase Fe4O2 results in the formation of NH3 and H2O without activation barriers. The key reaction is barrier free conversion of NO to N and H2O where the physical origin rests on negative-negative repulsion of NO over iron ...

The charge state of Ag and Au atoms and clusters (Ag4 and Au4, Ag5 and Au5) adsorbed on defective TiO2 anatase(101) and tetragonal ZrO2(101) has been systematically investigated as a function of oxide doping and defectivity using a DFT+U approach. As intrinsic defects, we have considered the presence of oxygen vacancies. As extrinsic defects, substitutional nitrogen- and niobium-doping have bee...

Nitrogen constitutes a significant defect in silicon (Si) as it can affect its mechanical properties. Substitutional nitrogen defects be created from interstitial during cooling of the crystal. In turn, substitutional atoms form micro-defects Si, most important which are oxygen since they have an impact on device’s characteristics. present paper, we study structure clusters Si consisting and at...

The characteristics of electronic states of Cd-vacancies in CdTe, an important semiconductor for various technological applications, are under debate both from theoretical and experimental points of view. Experimentally, the Cd-vacancy in its negative charge state is found to have C3v symmetry and a (-1/-2) transition level at 0.4 eV. Our first principles density functional calculations with hy...

Water extractable nitrate nitrogen, phosphate phosphorus and iron(II) in relation to the total amount of these essential elements were analyzed in fruits and seeds of medicinal plants. Water extraction was chosen to simulate in the analytical procedure the way plant samples are prepared and used by people. The total amounts of nitrogen, phosphorus and phosphate phosphorus were determined in the...

Given the limited resources of fossil energy, and the environmental risks of excess fertilizer on crops, it is time to reappraise the potential role of food legume biological nitrogen fixation (BNF) as sources of nitrogen for cropping systems in China. 150 soil samples across 17 provinces and 2 municipalities of China were collected and analyzed. A distribution map of the soil fertilities and t...