Abstract: The invention provides a two-dimensional chalcogenide, which is a crystalline material, and has a chemical formula of (NH4)2[Sn3S7]·(C4H13N3)1.41, cell parameters of a=b=13.2307(10) ?, c=19.335(2) ?, ?=?=90°, and ?=120°, and space group of P63/mmc. The invention further provides a method for preparing the two-dimensional chalcogenide and use thereof in the adsorption of iodine vapor. The two-dimensional chalcogenide of the present invention is capable of removing iodine vapor of various concentrations (as low as 400 ppm) over a wide range of temperatures (25° C.-75° C.), without desorption of iodine after standing for a long time.

Abstract: The invention provides a two-dimensional chalcogenide, which is a crystalline material, and has a chemical formula of (NH4)2[Sn3S7]·(C4H13N3)1.41, cell parameters of a=b=13.2307(10) ?, c=19.335(2) ?, ?=?=90°, and ?=120°, and space group of P63/mmc. The invention further provides a method for preparing the two-dimensional chalcogenide and use thereof in the adsorption of iodine vapor. The two-dimensional chalcogenide of the present invention is capable of removing iodine vapor of various concentrations (as low as 400 ppm) over a wide range of temperatures (25° C.-75° C.), without desorption of iodine after standing for a long time.

Abstract: A fin heat exchanger comprises a set of fins and a heat exchange tube alternating with the set of fins. A metal tube is bent multiple times and then folded at least once to form at least two columns of bent tubing, and then the heat exchange tube is inserted as a whole into the set of fins. In the heat exchanger, no damage resulting from a need for welding is caused to the heat exchange tube, thus the integrity of the heat exchange tube is protected; when a heat-exchange fluid flows through an integrated heat exchange tube, no impact damage is caused to the heat exchange tube as a result of a large fluid impact force, and no leaking of the fluid medium is caused by high-temperature fluid flowing into the heat exchange tube; the heat exchange performance of the heat exchange tube is guaranteed.