Kazuhito SHINTANI (新谷 一人)

1. The low-Reynolds number flow past an elliptic cylinder is investigated by using the method of matched-asymptotic expansion. The flow near the elliptic cylinder is characterized in terms of the singulaities arranged at the two foci of the ellipse. In the flow around a flat plate, which is a limiting case of the elliptic cylinder, a vortex appears at an edge of the plate when the angle of attack of a uniform flow is near a right angle, and twin voritices appear when the angle of attack of the uniform flow is a right angle.
2. The strain profiles in pyramidal quantum dots are calculated by using the molecular-dynamics simulation. It is shown that strain profiles at nanoscale should be evaluated by means of the simulation with the Stillinger-Weber potential, and that the continuum theory fails in evaluating the strains within islands of the small sizes below 10nm.
3. The deformation properties of single-walled carbon nanotubes under tensile strain are examined by means of the molecular-dynamics simulation. It is shown that the Poisson ratio of them depends on both the imposed strain and the chirality. Such dependences can be understood in the light of the nanomechanics of the honeycomb lattice.
4. An atomistic model of limited-thickness Si(001) epitaxy at low temperatures is deduced from the results of the deposition simulation of silicon atoms. 2×1 dimer rows formed on the transient surfaces are broken by adatoms to induce reconstruction of new dimer rows on the next layer. Breakdown of epitaxy occurs when such renewal of surface dimers ceases owing to the energetical stabilization of dimers.