Abstract: The present invention belongs to single cell sequencing related reagents, and specifically relates to a microsphere with a double-layer structure, wherein a material of an outer layer is a hydrogel (such as polyacrylamide containing disulfide bonds) which can be dissolved under certain conditions, and an inner layer thereof is a magnetic microsphere with oligonucleotide sequences. According to the present invention, the inner layer small microsphere of the double-layer microsphere is used as a substrate of oligonucleotide sequence molecular barcodes, the oligonucleotides are sequentially connected to the magnetic microsphere via chemical bonds created by means of enzymatic connection on the inner layer magnetic microsphere to synthesize the microsphere with unique sequences, and then the small microsphere is coated into a large-volume outer layer microsphere to prepare a double layer microsphere.

Abstract: Disclosed are a testing system and testing method for a magnetic refrigerator. In the system, an adjustable load includes a heating container, and a flow direction control structure. The heating container is provided with an inlet, an outlet, and a heater with controllable heating power. The flow direction control structure is configured to enable a heat exchange fluid flowing out from a cold end of any magnetic regenerator module in magnetic regenerator modules arranged in pairs to flow into a cold end of another magnetic regenerator module through the inlet and outlet of the heating container in sequence, the heater is used to heat the heat exchange fluid inside the heating container, and an on-off state between the adjustable load and the cold end of any magnetic regenerator module is controllable.

Abstract: The present invention is directed to a bi-stable coupling for controlling the depth of a tool insertion, such as drilling, and similar processes. The bi-stable coupling can be used to penetrate (e.g., drill or push) through a material layer of unknown thickness without plunging the tool into the adjacent layer. In accordance with the invention, in a first state, force is applied to the tool to initiate penetration and a reactive force maintains the device in the first state during penetration and when tool penetrates the material, the reactive force is diminished enabling the device to transition to a second state in which the tool becomes retracted. In medical applications, the invention allows for drilling through bone of unknown thickness without plunging into the adjacent soft tissue.

Abstract: The present invention is directed to a bi-stable coupling for controlling the depth of a tool insertion, such as drilling, and similar processes. The bi-stable coupling can be used to penetrate (e.g., drill or push) through a material layer of unknown thickness without plunging the tool into the adjacent layer. In accordance with the invention, in a first state, force is applied to the tool to initiate penetration and a reactive force maintains the device in the first state during penetration and when tool penetrates the material, the reactive force is diminished enabling the device to transition to a second state in which the tool becomes retracted. In medical applications, the invention allows for drilling through bone of unknown thickness without plunging into the adjacent soft tissue.