Abstract: A thermal management system for an electric forklift. The system includes a battery cooling circulation loop, a battery heating circulation loop, a cab cooling circulation loop, a cab heating circulation loop, a turn-on control unit, and a thermal management control module. The battery cooling circulation loop includes a battery cooling sub-loop and a refrigerant sub-loop. The battery cooling circulation loop and the refrigerant sub-loop are connected in parallel, and share an electric compressor and a condenser. The cab heating circulation loop and the battery heating circulation loop are connected in parallel, and share a heater and a second power unit. The turn-on control unit separately controls turn-on and turn-off of the loops. The thermal management control module controls the operation of the turn-on control unit and the loops according to battery temperature data in the electric forklift and/or a thermal management request inputted from the outside.

Abstract: An identification method of seabed weak echoes in airborne LiDAR bathymetry and a system thereof are provided, which belong to the technical field of marine surveying and mapping. The method includes: dividing sea area laser pulses into surface-seabed pulses or seabed-undefined pulses based on preprocessed data; using two-stage local maximum method to determine potential seabed echo positions of ALB waveforms and pre-generate seabed points; defining an ellipsoid neighborhood related to density and extracting spatial features of a pre-generated point cloud; constructing a BP neural network to identify seabed points in the pre-generated point cloud, and optimizing the identification result of the seabed points based on a laser pulse echo sequence and point cloud density.

Abstract: A spinning solution, a heat-resistant creep-resistant fiber and preparation method therefor are provided. The spinning solution includes a polyethylene, a solvent and a photoinitiator, and the content of the photoinitiator is 0.2 wt %-10 wt % of the mass of the polyethylene; gel-spinning and multi-stage drafting the spinning solution; then performing ultraviolet irradiation by an ultraviolet light source to obtain a heat-resistant creep-resistant polyethylene fiber; the light intensity and the time of the ultraviolet light source is 100 W/cm2-5000 W/cm2 and 10 s-600 s, respectively; the gel content and the crystallinity of the heat-resistant creep-resistant polyethylene fiber is 20 wt %-100 wt % and 50 wt %-90 wt %, respectively; the creep rate of the fiber is 10?8 s?1-10?7 s?1 under conditions of a temperature of 70° C. and a load of 300 MPa; the fracture temperature of the fiber is 155° C.-245° C. under conditions of a load of 15 MPa and a heating rate of 2° C./min.