Abstract: A resistance change memory device including: a cell array with memory cells arranged therein, the memory cell storing a resistance state as data in a non-volatile manner; a write buffer configured to supply voltage and current to a selected memory cell in accordance with data to be written in it; and a write control circuit configured to make a part of current supplied to the selected memory cell flow out in accordance with the selected memory cell's state change in a write mode.

Abstract: The present invention provides an optical fiber of which a zero dispersion wavelength falls within a range of between 1,250 nm and 1,350 nm inclusive, transmission loss at 1,550 nm is equal to or less than 0.185 dB/km, chromatic dispersion at 1,550 nm is within the range of 19±1 ps/nm·km, a dispersion slope at 1,550 nm is equal to or less than 0.06 ps/nm2·km, an effective area Aeff is equal to or more than 105 ?m2, a cable cutoff wavelength ?cc is equal to or less than 1,530 nm, polarization mode dispersion is equal to or less than 0.1 ps/km1/2, and a loss when the optical fiber is wound on a mandrel having an outer diameter of 20 mm is equal to or less than 10 dB/m.

Abstract: In a refrigerator having a compressor settled in a room temperature portion and an expander which is connected to the room temperature portion, a piston of the expander is settled in the room temperature portion and pressure variation at a low temperature portion is transferred to the piston through a gas column in a pipe connecting the room temperature portion and the low temperature portion.