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P. Han

Publications and source records attributed to P. Han.

2 recordsLinked to original sources

Large time decay properties of solutions to a viscous Boussinesq system in a half space

We consider the long time behavior of weak and strong solutions of the n-dimensional viscous Boussinesq system in the half space, with $n\geq3$ . The $L^r(R^n_+)$-asymptotics of strong solutions and their first three derivatives, with $1\leq r\leq\infty$, are derived combining $L^q-L^r$ estimates and properties of the fractional powers of the Stokes operator. For the $L^\infty-$asymptotics of the second order derivatives the unboundedness of the projection operator $P: L^\infty(R^n_+)\rightarrow L^\infty_σ(R^n_+)$ is dealt by an appropriate decomposition of the nonlinear term.

math.AP

Low-temperature electrical transport and double exchange in La(Pb,Ca)MnO

The resistivity in the ferromagnetic state of flux-grown La_{2/3}(Pb,Ca)_{1/3}MnO_3 single crystals, measured in magnetic fields up to 7 T, reveals a strong quadratic temperature dependence at and above 50 K. At lower temperatures, this contribution drops precipitously leaving the resistivity essentially temperature independent below 20 K. The Seebeck coefficient also reflects a change of regime at the same temperature. We attribute this behavior to a cut-off of single magnon scattering processes at long wavelengths due to the polarized bands of a double-exchange ferromagnet.

cond-mat.str-el