Abstract: A virtual teaching system for a dental periapical X-ray film and a virtual periapical X-ray film acquisition method is provided. The system includes a workstation and a dental radiography machine. The dental radiography machine includes a mounting plate, a stand column, a head fixing device, a five-axis robotic arm, a bulb tube, and a seat; the stand column is disposed on the top side of the mounting plate, and the head fixing device and the seat are respectively fixed on the upper and lower portions of the stand column; and the five-axis robotic arm includes five joint modules and five connecting rods, and the two ends of the five-axis robotic arm are respectively connected to the top portion of the stand column and the bulb tube. The workstation is communicatively connected to the dental radiography machine.

Abstract: A ray-free dental X-ray periapical film virtual imaging method based on virtual reality (VR) includes: constructing a VR positioning system, and tracing a position of a tracker bonded bound with a tube of a dental film machine and a spatial attitude matrix in real time; scanning and reconstructing a digital three-dimensional (3D) model of dentition; respectively setting different materials and transparency for a shell of a tooth model and an internal pulp cavity; constructing a virtual environment of a simulated oral cavity; assigning an attitude and position of the tracker to a virtual camera by using a network communication module, and controlling the virtual camera to move; placing the tracker in a specific position and orientation to calibrate so as to obtain a position coordinate of a dentition model in the virtual environment; and aligning the tube to teeth, and rendering a virtual periapical film.

Abstract: A method for geochemical gradient exploration includes the steps of: densely collecting soil samples and gas samples along a longitudinal direction in a certain depth range of a superficial layer; collecting soil samples and gas samples in the range from 1 meter to 50 meters deep by a special drilling machine; after analyzing and processing the geochemical indicators, extracting and figuring the bathymetric curve and the curve of gradients, the section curve and section curve of gradient along a certain direction, contour section of various indicators and contour section of various indicator gradients, so as to process the data and to represent the figure in 3D. More information, especially the variation information along the longitudinal direction, can be obtained. Gradient prospecting is realized by collecting samples along the depth direction and by analyzing variations in geochemical indicators along the depth.

Abstract: Disclosed herein is a three dimensional small bin electromagnetic consecutive array data acquisition method used in oil exploration comprising the steps of recording data using small bin lattices on execution of arrangement electrodes, each acquisition station (Ex, Ey) records the natural electromagnetic field time series data with the same acquisition parameter simultaneously; interference is removed first, for recorded data processing to get interference-free data; for border points and center point, the recording point serves as center point, and the same component from adjacent two points to total points area added together to obtain the average value of electric field data at time domain for each observation point; for corner points, the average values of the same electric field component from adjacent two points to total survey points toward bin direction is calculated; the electric field components acquired in maximum space serve as the new electric field values respectively; new time series data acqui

Abstract: Disclosed herein is a three dimensional small bin electromagnetic consecutive array data acquisition method used in oil exploration comprising the steps of recording data using small bin lattices on execution of arrangement electrodes, each acquisition station (Ex, Ey) records the natural electromagnetic field time series data with the same acquisition parameter simultaneously; interference is removed first, for recorded data processing to get interference-free data; for border points and center point, the recording point serves as center point, and the same component from adjacent two points to total points area added together to obtain the average value of electric field data at time domain for each observation point; for corner points, the average values of the same electric field component from adjacent two points to total survey points toward bin direction is calculated; the electric field components acquired in maximum space serve as the new electric field values respectively; new time series data acqui