Abstract: An inkjet printing apparatus adopting short pulse heating is designed to output a uniform image without unevenness. To this end, in a serial inkjet printing apparatus, a print head is subjected to a short pulse heating treatment before each print scan is carried out. In a case where a print medium is a first print medium, the print head is heated to a first target temperature before carrying out each of the print scans. In a case where the print medium is a second print medium, the print head is heated to a second target temperature lower than the first target temperature before carrying out each of the print scans.

Abstract: A first type of superconductive photoelectric device is provided by a superconductive thin film located between two electrodes. The superconductive thin film is one which has a photo-conductive effect and converts from a normally conducting state to a superconductive state in response to light irradiation. The superconductive thin film is preferably formed of a compound semiconductor of Pb chalcogenide added with Pb and/or In added beyond the stoicheometry of the compound semiconductor, such as Pb.sub.1-x Sn.sub.x Te+In, so as to generate precipitations of Pb. A second type of superconductive photoelectric device is provided by a photo-conductive material formed of Pb.sub.1-x Sb.sub.x Te filled in a gap between two superconductive electrodes, where the gap width is shorter than 500 times of a coherence length.

Abstract: A welding DC power supply system suitable for consumable or non-consumable electrode welding, including plural inverter units for converting a first direct current into an alternate current and for rectifying the alternate current to produce an output of a second direct current; a circuit connecting the output of terminals of the inverter units in parallel; a detection circuit for detecting the total output current of the inverter units; and a circuit for varying the number of operating inverter units according to the value of the detected total output current.