Abstract: A method for producing polyoxymethylene dimethyl ethers using fluidized bed reactor is provided. The fluidized bed reactor gives high conversion of feedstock during synthesis of polyoxymethylene dimethyl ethers. The product separation process includes pre-rectification, extractive rectification and vacuum rectification in series. In the pre-rectification process, the side-draw fraction PODE2 is recycled into the fluidized bed reactor, thus product distribution and selectivity to target components in the reactor can be improved. The extractive rectification process realizes coupling of neutralization, extraction, recovery of unconverted feedstock and products separation, thus significantly simplifies the process. The method for preparation of polyoxymethylene dimethyl ethers in this invention is simple, and has high conversion of feedstock, low energy cost and high selectivity to products.

Abstract: Disclosed are a method and a device for security-inspection of liquid articles with dual-energy CT imaging. The method comprises the steps of obtaining one or more CT images including physical attributes of liquid article to be inspected by CT scanning and a dual-energy reconstruction method; acquiring the physical attributes of each liquid article from the CT image; and determining whether the inspected liquid article is dangerous based on the physical attributes. The CT scanning can be implemented by a normal CT scanning technique, or a spiral CT scanning technique. In the normal CT scanning technique, the scan position can be preset, or set by the operator with a DR image, or set by automatic analysis of the DR image.

Abstract: An inspection system for air cargoes, in which an accelerator, a collimator, and a vertical detector arm are all mounted on the floor; detectors are provided within both the horizontal detector arm and the vertical arm; the accelerator, the collimator, the horizontal detector arm and the vertical detector arm are provided in a same plane; the horizontal detector arm is supported by the upper end of the collimator, the vertical detector arm and the horizontal detector arm are connected to each other and provided in the side opposite to the accelerator; a stable portal-shaped frame is formed by means of the collimator, the horizontal detector arm and the vertical detector arm; the conveying device is located under the horizontal detector arm, being perpendicular to the portal-shaped frame, the collimator is provided between the conveying device and the frame.