Abstract: A pulse tube refrigerator which can generate cryogenic temperatures of below 10 K includes first and second refrigeration stages. Each stage includes a pulse tube and an associated regenerator provided at the low temperature side of the pulse tube. A pressure fluctuation generator having a compressor and a first to a fourth valve is provided at the high temperature side of each regenerator. The high temperature sides of each pulse tube are connected by a continuous channel while the high temperature side of each pulse tube and the high temperature side of each regenerator are connected by a by-pass channel. A magnetic material having a rare-earth element and a transition metal is used as a regenerative material for the regenerator. When pressure fluctuation is generated in each pulse tube at the phase difference angle of 180.degree.

Abstract: A multi-staged gas cycle refrigerator having a first stage regeneration part including a compression piston, a second stage regeneration part including a double inlet pulse tube and a buffer is described. Temperatures below 10K are achieved without leakage of refrigerant gas, this configuration resulting in the improvement of efficiency and reduction of cost.

Abstract: A culture system comprising at least first and second culture medium tanks including a gas phase, a culture medium phase, at least one gas phase port, and at least one culture medium port. At least one culture vessel. First switching-over members have a plurality of culture medium flow passages connected between the tanks and the culture vessels. The culture medium phase of the first tank flows through the passages to the culture medium phase of the second tank via the culture vessel. Switching-over of the culture medium flow passages causes the culture medium phase of the second tank to flow through the passages to the culture medium phase of the first tank via the culture vessel. Gas supply section comprises at least two pressure chambers and at least two gas ports connected to the pressure chambers. Second switching-over members have formed therein a plurality of gas flow passages allowing a gas to flow from the gas control section to the gas phase in the first and second tanks.

Abstract: A substance for reversibly absorbing and desorbing hydrogen is disclosed. The substance comprises a complex dispersing 0.8-20% by weight of one or more than two oxides selected from La, Ce, Nd, Pr, Sm and Eu into Zr(FeV).sub.x (0.01.ltoreq.x.ltoreq.0.88).

Abstract: A substance for reversibly sorbing and desorbing hydrogen is disclosed. The substance comprises a complex dispersing 0.8-20% by weight of one or more than two oxides selected from La, Ce, Nd, Pr, Sm and Eu into ZrV.sub.x (0.01.ltoreq.x.ltoreq.0.7).