A pulse tube cryocooler is furnished with a second-stage cooling stage and an insert. The second-stage cooling stage has a lateral-surface opening, and a first heat-exchange surface extending in a sideways direction from the lateral-surface opening into the second-stage cooling stage. The insert includes a base-end portion fixedly fitted into the second-stage cooling stage to plug the lateral-surface opening, and a second heat-exchange surface that extends in the sideways direction from the base-end portion and is disposed inside the second-stage cooling stage, opposing the first heat-exchange surface. Between the first heat-exchange surface and the second heat-exchange surface the insert forms a clearance that flows a working gas, bringing both the first heat-exchange surface and the second heat-exchange surface into contact with the working gas.

The disclosed subject matter includes an active control alternating-direct flow hybrid mechanical cryogenic system, and relates to the field of cryogenic refrigeration technologies. The active control alternating-direct flow hybrid mechanical cryogenic system includes a main compressor, a Stirling cold finger, an intermediate heat exchanger, a pulse tube cold finger, a first dividing wall type heat exchanger, a final precooled heat exchanger, a second dividing wall type heat exchanger, and an evaporator that are communicated successively, where the second dividing wall type heat exchanger is connected to the evaporator through a second connecting pipeline, and a throttling element is disposed on the second connecting pipeline; a pulse tube cold head of the pulse tube cold finger is communicated with the final precooled heat exchanger through a cold chain; and a check valve is disposed on the intermediate heat exchanger.

A pulse tube cryocooler includes a pulse tube that includes a tube inner space, and an integral flow straightener that includes a flow straightening layer disposed to face the tube inner space so as to straighten a refrigerant gas flow from the tube inner space or into the tube inner space and a heat exchange layer formed integrally with the flow straightening layer outside the flow straightening layer with respect to the tube inner space so as to exchange heat with the refrigerant gas flow by contact with the refrigerant gas flow and is disposed at a low-temperature end and/or a high-temperature end of the pulse tube. The flow straightening layer includes a plurality of protrusions that protrude from the heat exchange layer toward the tube inner space.

An apparatus for exchanging heat with a fluid includes a heat exchanger having first and second opposing surfaces and a plurality of flow passages permitting axial fluid flow between the surfaces. A manifold having an interface surface is in thermal contact with the first surface and includes a thermally conductive body for conducting heat in an axial direction between the interface surface and a heat transmitting surface. A plurality of feed passages extend through the thermally conductive body in a transverse direction, the passages having an inlet for receiving or discharging fluid. A plurality of distribution passages have ends in fluid communication with at least one of the feed passages and openings distributed over the interface surface. The distribution passages are configured to cause a change in fluid flow direction between a transversely directed flow in the feed passages and an axially directed flow at the openings.

A thermoacoustic energy conversion system includes a closed circumferential encasing filled with a working fluid through which an acoustic wave can propagate in a propagation direction in use of the system, and at least one assembly of two heat exchangers with a regenerator sandwiched there-between arranged in said encasing. The at least one assembly is arranged substantially parallel to a local longitudinal axis of the encasing.

A cryogenic refrigerator includes a pulse tube cryocooler including a pulse tube, and a pulse tube cryocooler rotating mechanism that rotatably supports the pulse tube cryocooler allowing it to be changed from a cooling posture to a heating posture. When the pulse tube cryocooler is in the cooling posture, an inclination angle formed between a vertical line and a center axis of the pulse tube is a first angle, and when the pulse tube cryocooler is in the heating posture, the inclination angle is a second angle. In a case where the inclination angle formed when a cold end of the pulse tube faces vertically downward is defined as zero degrees and the inclination angle formed when the cold end of the pulse tube faces vertically upward is defined as 180 degrees, the second angle is larger than the first angle.

A cryocooler superconducting quantum interference (SQUID) system includes a cryocooler including a cold head, a cold head chamber in which the cold head is disposed, a sensor chamber including a SQUID sensor cooled to a low temperature by the cryocooler; and a connection block connecting the cold head and a thermal anchor disposed in the sensor chamber to each other to cool the SQUID sensor in the sensor chamber.

Disclosed is a sub-Kelvin temperature zone refrigeration mechanism. The sub-Kelvin temperature zone refrigeration mechanism includes a pulse tube refrigeration unit, first pre-cooling heat exchangers, a throttling refrigeration unit, second pre-cooling heat exchangers, an adsorption refrigeration unit, a third pre-cooling heat exchanger and a dilution refrigeration unit. The pulse tube refrigeration unit includes a pulse tube refrigeration part. The throttling refrigeration unit includes a throttling refrigeration part, and the throttling refrigeration part is connected with the adsorption refrigeration unit through the second pre-cooling heat exchangers so as to pre-cool the adsorption refrigeration unit. The adsorption refrigeration unit includes an adsorption refrigeration part, and the adsorption refrigeration part is connected with the dilution refrigeration unit through the third pre-cooling heat exchanger. The dilution refrigeration unit includes a dilution refrigeration part, and the dilution refrigeration part is a refrigeration terminal of the sub-Kelvin temperature zone refrigeration mechanism.

A method includes exposing a non-aqueous solution to ultraviolet illumination, where the non-aqueous solution includes one or more lanthanide elements and one or more photo-initiators. The method also includes producing lanthanide nanoparticles using the non-aqueous solution. The non-aqueous solution could be formed by mixing a first non-aqueous solution including the one or more lanthanide elements and a second non-aqueous solution including the one or more photo-initiators. The non-aqueous solution could include one or more metallic salts, where each metallic salt includes at least one lanthanide element. The one or more metallic salts could include erbium chloride, and the one or more photo-initiators could include benzophenone. The non-aqueous solution could include an organic solvent, such as an alcohol.

A heat exchanger for a cryogenic cooling apparatus is provided. The heat exchanger has a first conduit, a second conduit and a chamber, wherein the chamber is arranged to receive a fluid from the first conduit, and wherein second conduit is thermally coupled to the outside of the chamber. The chamber has a first region and a second region, the first region separated from the second region by a plate extending through the chamber, the plate comprising one or more apertures for allowing a flow of the fluid from the first region to the second region.