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We report atomic scale studies of the effect of applied strain and hydrogen environment on the reconstructions of the (105) Si and Ge surfaces. Surface energy calculations for monohydride-terminated (001) and (105) reconstructions reveal that the recently established single-height rebonded model is unstable not only with respect to (001), but also in comparison to other monohydride (105) structures. This finding persists for both Si and Ge, for applied biaxial strains from -4% to 4%, and for nearly the entire relevant domain of the chemical potential of hydrogen, thus providing an explanation for the recently observed H-induced destabilization of the Ge(105) surface.
We propose a scenario for a periodic filling and emptying of the accretion disc of GRS 1915+105, by computing the mass transfer rate from the donor and comparing it with the observed accretion rate. The binary parameters found by Greiner et al. (2001
An extensive theoretical investigation of the nonpolar (10$bar{1}$0) and (11$bar{2}$0) surfaces as well as the polar zinc terminated (0001)--Zn and oxygen terminated (000$bar{1}$)--O surfaces of ZnO is presented. Particular attention is given to the
A complete knowledge of absolute surface energies with any arbitrary crystal orientation is important for the improvements of semiconductor devices because it determines the equilibrium and nonequilibrium crystal shapes of thin films and nanostructur
We present multiepoch VLBA observations of the compact jet of GRS 1915+105 conducted at 15.0 and 8.4 GHz during a {it plateau} state of the source in 2003 March-April. These observations show that the compact jet is clearly asymmetric. Assuming an in
Owing to their shallow stellar potential, dwarf galaxies possess thick gas disks, which makes them good candidates for studies of the galactic vertical kinematical structure. We present 21 cm line observations of the isolated nearby dwarf irregular g