The transport properties and magnetoresistance of electron-doped manganate / insulator composites (La 0.8 Te 0.2 MnO 3 ) 1−x /(ZrO 2 )x (x = 0, 0.3, and 0.5) are investigated. It is found that the metal-insulator transition temperature of this system shifts to a lower value as the ZrO 2 content increases. The introduction of ZrO 2 enhances both the domain scattering and electron relative scattering in the metal transport region. In the adiabatic small polaron hopping transport region, the thermal activation energy seems invariable regardless of the ZrO 2 content. The application of a magnetic field promotes the charge transportation capabilities of the composites, and the magnetoresistance is enhanced with an increase of the ZrO 2 content. This could be attributed to the more remarkable modification effect of magnetic field on ordering degree in the composites than in pure La 0.8 Te 0.2 MnO 3 .

Directional solidification of SCN-3wt% H2O was carried out under externally imposed parallel shear flow, and the growth characteristics of dendritic tips, primary arms and secondary arms were investigated. A bright band related to solute boundary layer along the dendritic tip is observed for the first time. It was confirmed that the left-right symmetry of the dendritic tip is broken up by the shear flow, with the dendritic tip tilting toward the upstream side. The tilting angle increases with the pulling rate. Compared with the case of static condition, the primary spacing becomes lager under shear flow, and this is due to the coupling effect of flow and solute fields. The growth of secondary arm is promoted at the upstream side whereas greatly restrained at the downstream side, which is caused by the circumfluence among dendrites produced by force flow.