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To study brain mechanisms of memory scan, we have measured event-related potentials (ERPs) during the execution of a Sternberg task concerned with movement directions of random dot patterns (RDPs). Five healthy male subjects participated in the experiment. Event-related potentials were recorded at 20 electrode positions over the entire head. A prominent positive ERP component peaking at 380–390 ms known as P300 was observed in the parietal region after the presentation of the probe moving random dot pattern, whereas the P300 was not observed after the presentation of a control stationary RDP. On the other hand, a positive ERP component peaking at 127 ms was commonly observed in the occipital region after the presentation of both moving and control stationary RDPs. These findings suggest that P300 may reflect cortical activities related to the memory scan of movement directions of RDP.

The In—Ga—P ternary phase diagram in the low temperature region, 600–800°C, in the In-rich corner has been experimentally obtained and calculated based on the quasi-regular model with the assumption of a non-ideal solid. The liquidus lines were determined at 600, 650, 700, 750 and 800°C by weight loss method. The solidus compositions were measured on the epitaxial layers grown by the temperature difference method. Fairly good agreement between the data and calculated results was obtained.

GaP LPE layers were successfully grown from indium solvent. The lowest temperature at which a smooth layer was obtained was 580° C. The background carrier concentrations of the undoped layers grown at temperatures below 670° C were 1−6 × 10 15 cm -3 . It was found that this low background value was not due to the high level compensation. Low temperature growth is found to be effective to obtain high purity GaP crystals.

The Ga-Al-P ternary phase diagram in the low temperature region below 1000°C has been experimentally obtained and calculated based on the quasi-regular model. The liquidus lines were determined at 800, 850, 950, 1000 and 1040°C by weight loss method. The solidus compositions were measured on the epitaxial layers grown by the temperature difference method at 800, 850, 950 and 1000°C. Fairly good agreement between the data and calculated results was obtained.