Abstract: A device and a method for nondestructively detecting a transient characteristic of a conductive screw of a turbo-generator rotor are provided. The device includes a personal computer (PC), an extremely-steep pulse generator, an ultra-high-frequency double-isolation transformer, and a pulse emitting and coupling module, which are connected in sequence. The pulse emitting and coupling module is connected to a load. A synchronous pulse receiving non-inductive divider circuit synchronously receives a characteristic waveform from the load, and the synchronous pulse receiving non-inductive divider circuit is connected to an ultra-high-speed analog/digital (A/D) module through a nonlinear saturation amplifying circuit that amplifies a signal. The PC receives a signal from the ultra-high-speed A/D module. The load includes a positive or negative excitation lead loop that is in a 180° symmetrical and instantaneous short-circuit state and a rotor shaft.

Abstract: Disclosed are a method and system for optical calibration of a 3D printer. The method includes: projecting, by an optical apparatus, a projection image to a projection platform, placing a calibration plate on the projection platform, and capturing the projection platform; identifying the coordinates of calibration points and the coordinates of actual projection points according to the captured image to obtain a matrix of calibration points and a matrix of actual projection points; rotating and translating the matrix of the calibration points and/or the matrix of the actual projection points, and calculating a distance value T0 between the calibration points and the actual projection points in an image coordinate system; converting the T0 in the image coordinate system into an offset C1 in a pixel coordinate system, and inversely distorting an initial ideal projection image according to the offset C1 to offset optical distortion.

Abstract: A three-dimensional prediction method based on geology-seismology for a favorable metallogenic site of a sandstone-type uranium deposit is provided, including: determining a to-be-explored area and a target stratum in the to-be-explored area; setting a seismic line in the to-be-explored area, so as to acquire seismic data of a profile where the seismic line is located; delineating a depression region and a target region in the profile; determining a dip angle of a stratum in the target region and a dip angle of a stratum underlying the target region according to the seismic data, where the stratum underlying the target region is within the depression region; determining a distribution of fractures in the target region and the depression region according to the seismic data; and delineating a uranium deposit metallogenic site in the target region.

Abstract: An application and a method of compounds inhibiting synthesis of very long chain fatty acids (VLCFAs) in preventing and controlling microbial pathogens are provided, which relate to the technical field of plant pathology and plant disease prevention and control. In particular, an application method of a compound for inhibiting the synthesis of VLCFAs in preventing and treating microbial pathogens is provided. Research results associated with the methods show that taking the synthesis of VLCFAs as the target, microbial pathogens can be inhibited by using compounds that inhibit the synthesis of VLCFAs. Therefore, the compounds inhibiting the synthesis of VLCFAs can be used in preventing and treating microbial pathogens diseases, which provides a new idea or strategy for the prevention and treatment of microbial pathogens diseases, and provides more choices for the types of drugs for the prevention and treatment of pathogenic diseases.