Abstract: A transmission gear box is provided, which comprises a box body (10), at least one end cover (20, 20?) and a fitting structure. A cavity suitable for arranging gears is defined in the box body (10). The at least one end cover (20, 20?) is fixed on at least one opening end, which is axially opened, of the cavity of the box body (10). The fitting structure comprises an inner fitting surface (11) provided on the surface of the cavity of one of the box body (10) and the end cover (20, 20?), and an outer fitting surface (21) provided on the peripheral surface of the other one of the box body and the end cover, and the inner fitting surface (11) and the outer fitting surface (21) are fixed to each other by means of welding. At least one clearance fit area (30) and interference fit areas (40) located on both sides of the clearance fit area (30) are configured between the inner fitting surface (11) and the outer fitting surface (21).

Abstract: The present invention relates to a motor, comprising: a motor housing, a cavity being formed inside the motor housing, a stator assembly and a rotor assembly being accommodated in the cavity, two ends of the motor housing being provided with an opening; an end cover, the end cover being arranged at one side of the motor housing and used for sealing the opening at said side; a flange portion, the flange portion sealing the opening at the other side of the motor housing; the rotor assembly is provided with a rotor shaft, one end of the rotor shaft passing through the end cover, the other end passing through the flange portion; a magnetic ring, the magnetic ring being arranged on the rotor shaft and located at the side of the end cover away from the motor housing; output teeth, the output teeth being arranged on the rotor shaft and located at the side of the flange portion away from the motor housing.

Abstract: Disclosed are an intermediate of Eribulin and a preparation method therefor. In particular, disclosed are compounds as represented by formula II, formula III and formula V and a preparation method therefor. Ar is C1-10 alkyl substituted, alkyloxy substituted or unsubstituted aryl; R1 and R2 is an acetal protecting group or a thioacetal protecting group; R3 is hydrogen or a hydroxyl protecting group; and X is halogen or a leaving group. The preparation method therefor has the advantages of mild reaction conditions, high selectivity, easy purification, low synthesis cost and the like, being suitable for large scale production.

Abstract: The present invention relates to an amphiphilic block copolymer represented by formula I, a preparation method thereof, and a nanomicelle drug delivery system formed from the copolymer and a poorly soluble drug. The amphiphilic block copolymer includes a hydrophilic chain segment, a hydrophobic chain segment, and a linker for linking the hydrophilic chain segment to the hydrophobic chain segment. The linker contains an unsaturated structure, which can enhance the interaction between the poorly soluble drug and the copolymer to improve the drug loading ability and stability of the nanomicelle. The invention also relates to a nanomicelle drug-loading system, a preparation method thereof, and the use of the nanomicelle drug-loading system for preparing medicines for treating tumors, inflammation, diabetes, central nervous system diseases, cardiovascular diseases, and psychological disorders.

Abstract: Disclosed are an intermediate of Eribulin and a preparation method therefor. In particular, disclosed are compounds as represented by formula II, formula III and formula V and a preparation method therefor. Ar is C1-10 alkyl substituted, alkyloxy substituted or unsubstituted aryl; R1 and R2 is an acetal protecting group or a thioacetal protecting group; R3 is hydrogen or a hydroxyl protecting group; and X is halogen or a leaving group. The preparation method therefor has the advantages of mild reaction conditions, high selectivity, easy purification, low synthesis cost and the like, being suitable for large scale production.