Combining density functional theory calculations for molecular electronic structure with a Green function method for electron transport, we calculate from first principles the molecular conductance of benzene connected to two Au leads through different anchoring atoms-S, Se, and Te. The relaxed atomic structure of the contact, different lead orientations, and different adsorption sites are full...

in this paper, the nucleation and growth of diamond/diamond-like coatings on austenitic (aisi 316) and ferritic (aisi 430) stainless steel substrates have been investigated using torch technique. the effects of substrate surface preparation has also been studied. the quality of coatings produced has been examined using optical and scanning electron microscopy, x-ray diffraction, raman spectrosc...

The effect of the exchange-correlation potential in ab initio electron transport calculations is investigated by constructing optimized effective potentials using different energy functionals or the electron density from second-order perturbation theory. The authors calculate electron transmission through two atomic chain systems, one with charge transfer and one without. Dramatic effects are c...

Ž . An analytical expression of the electron density function r r due to Schwartz for two-electron atomic systems is applied to a detailed study of density-dependent properties of relatively heavy two-electron ions. Comparison of the Schwartz results with those from accurate Hartree]Fock and Hylleraas wave functions shows that despite its simple yet analytical form, the Schwartz density has a q...

Dual Energy techniques allow an estimation of the effective atomic number and electron density through identification of the photoelectric and compton scattering components in the attenuation coefficient. However in the context of material identification, it is substantially more usefull to try and identify the material type and the thickness of the sample under investigation. Several simulatio...

introduction:  skin  sparing  is  one  of  the  most  desirable  characteristics  of  high  energy  photon  beams. however, the photons emerging from the target of linacs are contaminated by secondary  electrons  as  a  result  of  their  interactions  with  air,  collimators,  flattening  filter  and  any  other  objects in their path. this phenomenon tends to increase the skin dose received b...

The Thomas-Fermi method [1] [2] was designed for the calculation of the electron density in a heavy atom, by treating the electrons as locally free. Lieb and Simon [3] showed that the treatment is exact in the limit when the atomic number goes to infinity. Application to a confined Bose condensate was pioneered by Goldman, Silvera, and Legget [4], and by Oliva [5], and recently reconsidered by ...

New image processing methodologies and algorithms have greatly contributed to the signi cant progress in three-dimensional electron microscopy (3DEM) of biological complexes we have seen over the last decades. Naturally, the availability of accurate procedures for the objective testing of new algorithms is a crucial requirement for the further advancement of the eld. A good and accepted testing...