アイテム詳細

要旨

The motion of dislocations in convective roll patterns provides an important wavevector selection mechanism. In this work the structure and velocity of dislocations is calculated near threshold using amplitude equations appropriate for systems with an axial anisotropy. The fact that then the roll pattern has a preferred direction leads to characteristic differences to isotropic systems like Rayleigh-B?nard convection in simple fluids. Furthermore the nucleation process of dislocation pairs is discussed by analyzing the threshold solution that describes the nucleation barrier.