Abstract: Disclosed are a method and system of magnetotelluric synchronous detection and real-time inversion. The system includes a detection and inversion host (M) with wireless networking function and N2-1 detection and inversion extensions (Si) with wireless communication functions. The distance between each two detection and inversion extensions (Si) is D, i=1, 2, . . . , N2-1, and N is an odd number. The detection and inversion host is configured for collecting magnetic field signals and electric field signals at measurement points, wireless networking and cooperation, synchronous detection and real-time inversion control of the detection and inversion extensions (Si) in detection area. The detection and inversion extensions (Si) are configured for synchronous collection of electric field signals at measurement points and real-time inversion of detection data at measurement points under cooperative control of the detection and inversion host.

Abstract: A sensorless control method and an apparatus for a three-phase switched reluctance motor. The sensorless control method obtains line inductances of three phases according to real-time phase inductances of the three-phase switched reluctance motor and then determines feature points of the line inductances of the three phases. A position angle of the rotor at any time in the next corresponding region is calculated according to an average rotation speed of the rotor in the region corresponding to two adjacent feature points. A control signal is output to realize a precise sensorless control for the three-phase switched reluctance motor. The control apparatus includes a microcontroller, a power conversion circuit, a drive module for the power conversion circuit, a current detection module, a voltage detection module, an input and output module and a direct current regulated power supply.

Abstract: A modeling method of a stator winding air gap for temperature field analysis of an AC traction motor includes: changing the width of an air gap of a stator winding equivalent model according to a set value of spacing; establishing a three-dimensional finite element model of the AC traction motor with the stator winding air gap; based on the three-dimensional finite element model of different widths of the air gap, analyzing a temperature field to obtain a temperature field distribution diagram of the AC traction motor; carrying out the numerical fitting according to data in the temperature distribution diagram to obtain a function relation between the air-gap width and the temperature of the stator winding equivalent model; and by measuring the actual temperature of a motor stator winding, calculating an optimal air-gap width corresponding to the modeling of the stator winding of the current AC traction motor.

Abstract: Disclosed is a half-vehicle floating device and a half-vehicle position tracking method based on load feedback. The device includes a rack, an active platform, a position-measuring triangle frame and a position-measuring platform. Guide rails corresponding to the active platform and the position-measuring platform are provided vertically on the rack. The active platform and the position-measuring platform are respectively placed on a corresponding rail through a slider. The bottom of the active platform is hinged to a first corner of an active triangle frame through an active slider rod, and a second corner of the active triangle is hinged to the rack and connected to an inverter motor through a transmission device. The bottom of the position-measuring platform is hinged to a first corner of the position-measuring triangle frame through a position measuring slider rod, and a second corner of the position-measuring triangle frame is hinged to the rack.

Abstract: There is provided a wireline coring recovery system of a seafloor drilling rig, including: a winch, a rope, a submersible tension sensor, a cover, a main shaft and a catcher. One end of the rope is wound on the winch, and the other end of the rope is connected to an upper end of the catcher after the rope passes over a first pulley provided below the submersible tension sensor and then through a tapered hole on the cover. The catcher is provided in a center hole of the main shaft. The present application further provides a method of using the wireline coring recovery system. By the cooperation of the compression rod skewed teeth, the first rotating core skewed teeth, the second rotating core skewed teeth and the compression spring, the inner core barrel is readily recovered or released.

Abstract: A method for preparing titanium dioxide-based synthetic paper capable of degrading organic pollutants, including: adding thermoplastic polyurethane particles and N,N-dimethylformamide or N,N-dimethylacetamide in a reactor, heating, and stirring to fully dissolve the thermoplastic polyurethane particles in a solvent to obtain a polyurethane solution; adding titanium dioxide powder having photocatalytic degradation property in the polyurethane solution, stirring uniformly to obtain a solid-liquid mixture, and standing for defoaming; uniformly coating the solid-liquid mixture onto a piece of release paper, soaking the release paper coated with the solid-liquid mixture into an aqueous solution of sliver nitrate having photocatalytic degradation property, completely curing the solid-liquid mixture to form a film, and soaking the release paper and the film into an aqueous solution of sodium chloride; drying, cooling, removing the release paper, and cutting the film to a proper size to obtain the titanium dioxide-ba

Abstract: A method for preparing active carbon-based special synthetic paper capable of degrading harmful substances in environment, including: stirring polyurethane particles and a solvent in a reactor, and standing to completely dissolve the polyurethane particles to obtain a polyurethane solution; adding active carbon having harmful substances adsorption property in the obtained polyurethane solution, stirring and mixing uniformly to obtain a solid-liquid mixture; coating the obtained solid-liquid mixture onto a piece of release paper, soaking the release paper coated with the solid-liquid mixture into an aqueous solution of silver nitrate having photocatalytic degradation property, completely curing the solid-liquid mixture to form a film, and soaking the release paper and the film into an aqueous solution of sodium chloride; drying the obtained release paper and the film in an electric blast drying oven, and stripping the film from the release paper to obtain the active carbon-based special synthetic paper.

Abstract: The present disclosure discloses a pressure-retaining cap screwing and unscrewing device for a marine natural gas hydrate pressure-retaining rock-core barrel, wherein it comprises a cap-unscrewing chuck, a support cylinder, a pressure-retaining cap screwing and unscrewing head, a spring, a screwing and unscrewing shaft, and a pressure-retaining cap screwing and unscrewing sleeve, a reducer and a motor; an input shaft of the reducer is connected to the motor, an output shaft of the reducer is the screwing and unscrewing shaft which is a tubular structure with a plurality of guide holes provided on a side wall thereof. The device is simple in structure, compact, light in weight, and convenient to control, and the pressure-retaining cap can be discarded.

Abstract: A mathematical model between the optimization objects and the optimization objectives is established, with finite-time control parameters as optimization objects, and a total harmonic distortion of an output voltage, a deviation signal of a capacitor voltage and a deviation signal of an output current of BBMC as optimization objectives. A multi-objective optimization satisfaction function and a multi-objective optimization fitness function are established. Multiple sets of optimal finite-time control parameters are iteratively optimized using an adaptive wolf pack algorithm. Functional relationships between respective optimal finite-time control parameters and the corresponding actual output current of BBMC are obtained using a numerical fitting method. Optimal control parameters corresponding to any load are obtained according to the obtained functional relationships.

Abstract: Disclosed is a sediment core-drilling process for a submarine wire-line coring drill rig, including 1) lowering the drill rig; 2) drilling in a pressure-suction mode; 3) drilling in a rotation-pressure-suction mode; 4) cutting sediment cores; 5) recovering a core inner tube; 6) cleaning bottom of hole; 7) punching before adding a drill pipe; 8) lowering another core inner tube; 9) adding the drill pipe; 10) punching after adding the drill pipe; 11) repeating the steps 2)-10) until a given hole depth is reached; 12) recovering the drill pipe and a wire-line coring outer tube drilling tool; 13) recovering the submarine wire-line coring drill rig. The core-drilling process provided herein is suited to working conditions without mud lubrication and mud protection for hole wall. This invention has advantages of low disturbance and high efficiency in coring and is suitable for remote operation.

Abstract: Taking parameters of a main circuit in a BBMC as optimization objects, and a total harmonic distortion of an output voltage of the BBMC, a deviation between an actual output current and a corresponding rated output current as optimization objectives, a mathematical model between optimization objects and optimization objectives is established. A multi-objective optimization satisfaction function and a multi-objective optimization fitness function are established by selecting a current rating as a rated output current of the BBMC. An adaptive wolf pack optimization algorithm is adopted to obtain a set of optimal parameters of the main circuit. The rated output current is changed to obtain n sets of optimal parameters, and functional relationships between the optimal parameters of the main circuit in the BBMC are obtained using a numerical fitting method. Optimal parameters of the main circuit corresponding to different current ratings are determined according to the functional relationships.

Abstract: The invention disclosed an intelligent dehumidification device for a hot air circulation baking system, which internally includes a compressor, a condenser, a throttle valve, an evaporator, a total heat exchanger, a controller, a heat dissipation fan, a liquid level sensor, a temperature and humidity sensor, an axial flow fan, a drain solenoid valve, a condensate collecting box and a temperature sensor and externally includes a dehumidification air inlet, a dehumidification air outlet, a fresh air inlet, a heat dissipation air outlet and a condensate discharge port.

Abstract: An actual rotation speed of the asynchronous motor is detected according to the given rotation speed thereof. A given voltage of the asynchronous motor is obtained according to a vector control algorithm and a PI-IP control algorithm and is used as a reference output voltage of the BBMC. A duty cycle of a power switch tube in the BBMC is obtained according to a finite-time control algorithm by taking capacitor voltages and inductor currents in the BBMC as control variables of the speed regulation system. The conducting time of the power switch tube in the BBMC is controlled according to the duty cycle and an output control signal of a corresponding switching cycle, so that an output voltage consistent with its reference output voltage is obtained at an output end of the BBMC, so that the actual rotation speed of the asynchronous motor accurately tracks the given speed.

Abstract: A process for drilling natural gas hydrates. A drilling rig is placed in seawater. A suction-press core drilling mode is adopted in a soft sediment formation, a suction-rotary core drilling mode is adopted in a medium-hard sediment formation, or a pumping direction circle-rotary core drilling mode is adopted in a hard sediment formation. A core is extracted. An inner tube for wireline pressure coring is recovered. A holding seal cap is tightened, and the inner tube is stored in a pipe storage rack. Punching is carried out. An inner tube for wireline pressure coring which is hollow is captured to disengage the holding seal cap. The inner tube is lowered. A drill rod is added. The punching is carried out again. The above steps are repeated until the core drilling reaches a given drilling depth. The drill rod, the drill and the corer are recovered.

Abstract: Provided is a mechanical handheld hermetic sampler for marine sediment. The sampler comprises sampling assembly and a pressure maintaining assembly. The sampling assembly includes a sampling tube, a handle and an end cap. The sampling tube is fixed at a lower end surface of the end cap while the handle is fixed at an upper end surface of the end cap. The handheld robotic sampler for marine sediment with hermetic sampling is simple and compact in structure, small in size, light in weight, easy to manipulate and manufacture, highly reliable, and particularly suitable for robotic sampler hand control of underwater operating equipment such as a manned submersible, an unmanned submersible and Remotely Operated Vehicle.