No abstract

The resistivities in Al70Pd20Re10 alloy of the icosahedral phase are quite sample dependent, possibly due to slight variation of the alloy composition. In some samples, the resistivity at room temperature is ∼0.01 Ω·cm and that at 4.2 K is as high as ∼0.1 Ω·cm; these values are much higher than any values reported so far for quasicrystals. The temperature dependence of the conductivity is almost linear above 4.2 K, and the magnetoconductivity is negative. Such dependence is interpreted by the theory of weak localization which takes into account the spin-orbit scattering.

This paper attempts to show analytically that the energy-input spectra of damped SDOF systems and undamped MDOF systems excited by an earthquake motion can be predicted by smoothing the Fourier amplitude spectrum of the base acceleration. The spectral window for smoothing in the frequency domain for a damped SDOF system is identical with the probability density function of the time-variant or instantaneous vibration frequency resulting from non-linear hysteresis. The spectral window for an undamped MDOF system is identical with the set of squared participation factors associated with vibration modes. It was found that the increase in damping factor and the increase in participation of higher modes provide wider spectral windows, resulting in more flattened or unaltered energy-input spectra due to enhanced smoothing effects.

A promising method for studying intraband carrier dynamics in semiconductors is monitoring the evolution of far-infrared ͑FIR͒ absorption induced by photoexcited carriers. By monitoring the photoinduced FIR absorption as a function of magnetic field, we performed time-resolved cyclotron resonance of photocreated electrons in InSb with picosecond resolution.