Abstract: The present invention discloses a combined oxygen, nitrogen and hydrogen joint determination device and method based on thermal conductivity-infrared technique. In the device, a melting and extraction system comprises a carrier gas introduction pipeline, a chamber valve, an impulse furnace and a dust filter; an analytical gas transmission system comprises a flush valve, a bypass valve, a mass flowmeter and a first switching valve; a signal detection system comprises an infrared cell, an analysis purification reagent tube and a thermal conductivity cell; and a signal analysis system comprises a controller and a processor. The present invention realizes different joint determination modes by switching different gas paths, which can meet different determination requirements of different users.

Abstract: A method for detecting abnormal direct current voltage measurement in a modular multilevel converter high voltage direct current transmission system is provided. In the method, a valve group voltage at a detection pole is obtained, voltages at voltage measurement points at the detection pole are collected, and comparison and determination are performed based on the actual arrangement of the voltage measurement points, and then whether an abnormal measurement occurs at each of the voltage measurement points is determined.

Abstract: An interior rotating structure of a handicraft lantern comprises a lantern bracket, a transparent container, a sealed rotary mechanism, a mounting frame, a rear cover, and a motor body. The transparent container is fixed under the lantern bracket and the sealed rotary mechanism is inserted under the transparent container. The mounting frame is under the sealed rotary mechanism. A container sealing cover is installed in the sealed rotary mechanism, while a central impeller is mounted on the container sealing cover. The rotating structure includes a rotating gear and a shaft magnet on the motor shaft, so that the rotating gear drives a large inner ring gear to spin through multi-step transmission of a reduction gear set. The inner ring gear drives an impeller rotating bracket to rotate through the magnets, in such a way that the rotating bracket can agitate the liquid when the central impeller revolves at the same time.

Abstract: The invention is a polyoxymethylene film and a preparation method. The polyoxymethylene film comprises: 96 to 98 parts by weight of polyoxymethylene resin, 0.5 to 2 parts by weight of nucleating agent, 0.5 to 1 parts by weight of antioxidant, and 0.5 to 1 parts by weight of formaldehyde absorbent. In view of the high crystallinity and fast crystallization rate of polyoxymethylene, blown film process is used to directly blowing the molten mass extruded through a die of a screw extruder to form a blown film bubble. It is easy to form thin neck and easy to break when stretching, so the method is beneficial to form polyoxymethylene film, and has high processing efficiency, and is suitable for industrialization. Copolymerization unit —CH2—CH2—O— is introduced into the molecular chain of polyoxymethylene and its ratio is increased, thereby effectively reducing the crystallization rate of the materials and making it easier to form a film.