Abstract: A weeding device for crops having a seedling avoidance function includes a rack connected to a weeding machine. A hydraulic pump and two hydraulic cylinders are mounted to the rack. Bottom ends of each of the two hydraulic cylinders are provided with a vertically arranged support rod. An inter-row weeder is mounted to a bottom end of each of the two support rods. A slider configured to reciprocate in a horizontal direction is positioned on two slide rails that are mounted to the rack. An inter-plant weeder is mounted to a bottom side of the slider. A plurality of weeder blades are arranged side by side on the inter-plant weeder. At the weeding position, an arrangement direction of weeder blades is perpendicular to an advancing direction, and at the weed avoidance position, the arrangement direction of the weeder blades is parallel to the advancing direction, thereby avoiding crops.

Abstract: The present disclosure discloses a high-strength and high-thermal conductivity new material composite brake drum and a preparation method thereof. The composite brake drum is composed of an outer layer of high-strength ductile iron and an inner layer of high-thermal conductivity gray cast iron, which are integrated by centrifugal compound casting. The outer layer of the composite brake drum is firstly poured on the production line of iron particle-filled coated sand shells. Due to the fast solidification and cooling of the iron particle-filled coated sand shells, the castings have the characteristics of fine and dense organization structures to ensure the high strength and high toughness of the ductile iron of the outer layer. On this basis, the inner gray cast iron is poured under centrifugal casting conditions, in which a good metallurgical bond between the inner and outer layers is achieved by controlling the centrifugal casting process.

Abstract: A method using drive test data for propagation model calibration includes: step 1, obtaining original drive test data; step 2, selecting the data from the drive test data according to predefined conditions as effective drive test data; and step 3, extracting the effective drive test data to form a data file used for propagation model calibration. An apparatus using drive test data for propagation model calibration includes: a drive test data obtaining module, configured to obtain the drive test data in the regions to be calibrated; an effective drive test data generation module, configured to generate effective drive test data from the drive test data according to predefined conditions; and a data file generation module, configured to extract the effective drive test data to form a data file used for propagation model calibration. The present invention utilizes drive test data of existing networks to largely decrease the CW test work and reduce the network building cost.

Abstract: A method using drive test data for propagation model calibration includes: step 1, obtaining original drive test data; step 2, selecting the data from the drive test data according to predefined conditions as effective drive test data; and step 3, extracting the effective drive test data to form a data file used for propagation model calibration. An apparatus using drive test data for propagation model calibration includes: a drive test data obtaining module, configured to obtain the drive test data in the regions to be calibrated; an effective drive test data generation module, configured to generate effective drive test data from the drive test data according to predefined conditions; and a data file generation module, configured to extract the effective drive test data to form a data file used for propagation model calibration. The present invention utilizes drive test data of existing networks to largely decrease the CW test work and reduce the network building cost.

Abstract: A method using drive test data for propagation model calibration includes: step 1, obtaining original drive test data; step 2, selecting the data from the drive test data according to predefined conditions as effective drive test data; and step 3, extracting the effective drive test data to form a data file used for propagation model calibration. An apparatus using drive test data for propagation model calibration includes: a drive test data obtaining module, configured to obtain the drive test data in the regions to be calibrated; an effective drive test data generation module, configured to generate effective drive test data from the drive test data according to predefined conditions; and a data file generation module, configured to extract the effective drive test data to form a data file used for propagation model calibration. The present invention utilizes drive test data of existing networks to largely decrease the CW test work and reduce the network building cost.