We propose the generalization of a known established empirically (Wahl W. and Wucher A. Nucl. Instrum. Meth. B 94, 36(1994)) power law, describing relative mass-spectra of neutral sputtered clusters, on the cases of arbitrary cluster charges. The fluctuation mechanism of charge state formation of sputtering products in the form of large clusters with the number of atoms N ≥ 5 is also proposed. ...

Semiempirical and density functional theory (DFT) calculations have been performed on the key steps of the commonly accepted mechanism of the Pauson–Khand reaction (PKR). In this context, the high reactivity of ynamine complexes in the cycloaddition process has been rationalized on the basis of an anomerically assisted dissociation of CO. Moreover, an explanation has been provided for the corre...

Atmospheric ions participate in the formation of new atmospheric aerosol particles, yet their exact role in this process has remained unclear. Here we derive a new simple parameterization for ion-induced nucleation or, more precisely, for the formation rate of charged 2-nm particles. The parameterization is semi-empirical in the sense that it is based on comprehensive results of one-year-long a...

Pore-water solute transport processes acting in addition to molecular diffusion affect sediment biogeochemistry and benthic exchange fluxes. Given the relatively few direct measurements of enhanced transport intensities, there is a need for predictive relationships to calculate enhanced transport parameters from more readily available information. Here, enhanced diffusion coefficients and nonlo...

A quantitative structure activity relationship analysis was applied to a library of 51 benzylacetamide derivatives with anticonvulsant activity. The molecular structures of 51 compounds were optimized with the Semiempirical Method PM6 (Parametric Method-6) included in the MOPAC2009 software. The optimized structures of all the examined compounds were represented by 1497 DRAGON-type descriptors....

We present elemental abundances for multiple HII regions in Leo A and GR 8 obtained from long slit optical spectroscopy of these two nearby low luminosity dwarf irregular galaxies. As expected from their luminosities, and in agreement with previous observations, the derived oxygen abundances are extremely low in both galaxies. High signal-to-noise ratio observations of a planetary nebula in Leo...

â â â â  reza roshan [1] â  department of economics, university of sistan and baluchestan , iran â  mosayeb pahlavani â  department of economics, university of sistan and baluchestan, iran â  mohammad nabi shahyaki tash â  department of economics, university of sistan and baluchestan, iran â  â â â  abstract â  consumption is the principal feature of iran’s gross national production. therefor...

The reaction mechanism between (H2C) and (7, 0), zigzag single-walled carbon nanotubes(ZSWCNTs) on two different orientation of C-C have been studied by semi empirical AM!method. The activation barriers of (H2C) adding to (7, 0) ZSWCNT are computed and compared.The effects of diameters of zigzag SWCNT on their binding energies were studied

mndo semi-empirical scf mo calculations are used to study the pyramidal nitrogen atom inversion and configurational equilibria in the title compounds.

The adsorption mechanism of single thiophene (C4H4S), 4-thiophene (C16H10S4), and their dimers on the Cu(111) surface has been studied in the framework of the density functional theory (DFT). The importance of the London dispersion effects on the molecule-surface adsorption geometry and the corresponding binding energy was investigated by using semiempirical and first-principles methods. Intere...