A nanosecond pressure pulse is generated by focusing a nanosecond-pulsed laser onto an aluminum target with plasma confined geometry. A spatially uniform pressure pulse is generated by focusing laser beams with a flat-top spatial energy distribution. High-pressure pulse loading and recovery experiments were performed on yttria-doped (3 mol%) tetragonal zirconia polycrystals at 11 GPa. In the pressureloaded region, the monoclinic phase was uniformely formed. The transition ratio was approximately 30%. Nanosecond time-resolved Raman spectroscopy was performed on polytetrafluoroethylene under high-pressure pulse loading at 1 GPa, and rapid structural phase transition within 10 ns was revealed. q

No abstract

Hamiltonians in one space dimension of the &four and sine-Gordon classes are considered, emphasising kink-and breather-like excitations. A calculation of classical dynamic structure factors based on a kink ideal gas phenomenology is reviewed in terms of the 'central peaks' predicted. This phenomenological scheme is extended to include breather excitations. It is suggested that, for correlations of appropriate functions, the breather excitations can give rise to a low-frequency ('central') response from their particle-like envelope and a high-frequency response from their internal oscillatory motions, in qualitative accord with molecular dynamics simulations. + Although breather densities are not rigorously available, it is certainly reasonable to suppose nB(T; wB)exp(-PEB) in the same sense that nK-exp(-PE,) (equation (2.14)).

No abstract

The preparation and physical properties of polytetracyano-ethylene (TCNE) copper chelate film were studied. The reaction of TCNE with copper consists of the first rapid and the second slow processes. An optimized condition for the preparation was to heat for 9 to 24 hours at 400°C. Element analysis of carbon and copper, and electron probe microanalysis revealed nonuniform distribution of copper atoms across the film, about 30 % near the surface based on the copper plate and 20 % on the opposite side. The electrical conductivity shows a remarkable anisotropic effect in both directions of perpendicular and along the base side, with activation energy of 0.1 to 0.5 eV, and the highest conductivity of 10-1 mho.cm-1. Heat treatment changes the distribution of copper, free radical concentration, electrical conductivity, and dielectric properties of the film. Nonohmic conduction appears on the perpendicular direction and was interpreted as space-charge-limited mechanism. The excess copper atoms over the chelate composition (TCNE: Cu=2:1) may contribute to the high conductivity on the base surface and dielectric properties.