Abstract: An electrical prospecting signal transmission device capable of suppressing electromagnetic coupling interference, including a rectangular wave signal source, an output circuit for supplying power to the ground and a plurality of transmission channels. Each of the plurality of transmission channels includes an isolated driving circuit, a low-pass filter circuit and a power amplification circuit connected sequentially in series. The rectangular wave signal source is configured to generate a rectangular wave or a composite rectangular wave. A signal output terminal of the rectangular wave signal source is connected to an input terminal of the isolated driving circuit, and an output terminal of the power amplification circuit is connected to the output circuit to supply power to the ground.

Abstract: A method and system for controlling a vibration of a rotor in a turboshaft engine are provided. The method includes: establishing, based on a kinetic model for a rotor-casing system, a mapping matrix indicating a correspondence among an unbalance, an oil film clearance, and a vibration response; performing determination on a real-time vibration response, and skipping adjustment if the real-time vibration response is smaller than a response threshold; otherwise, approximately matching a real-time oil film clearance and the real-time vibration response with the mapping matrix to obtain a real-time unbalance; obtaining, based on the real-time unbalance and the mapping matrix, a preferred vibration response, and further obtaining a preferred oil film clearance; based on the preferred oil film clearance and the real-time oil film clearance, obtaining a clearance adjustment amount; generating a control signal based on the clearance adjustment amount, and performing adjustment based on the control signal.

Abstract: To solve the problem of large electromagnetic noise in AC traction motor, embodiments have open square notches at symmetrical positions on both sides of stator teeth of AC traction motor to effectively reduce electromagnetic noise without affecting other performance indicators of motor. In addition, embodiments fit the functional relationship between the optimal notch size or optimal slotting position size of motors and their power by determining the optimal notch size or optimal slotting position size of motors with different power grades, so as to achieve the noise reduction effect.

Abstract: A suction sampler system for in situ collection of deep-sea floor organisms includes a pressure-retaining cylinder, a pressure compensation device, a cone component, semiconductor refrigeration components, a circuit cylinder and a collection cylinder. Two ends of the pressure-retaining cylinder are respectively equipped with a first and second seal mechanisms, and the cone component is arranged in the pressure-retaining cylinder. The pressure compensation device is connected to the pressure-retaining cylinder through a high-pressure pipe. The semiconductor refrigeration components are arranged outside the pressure-retaining cylinder. The circuit cylinder is equipped with a power supply and a controller, and the semiconductor refrigeration components are connected to the controller. A pressure sensor and a temperature sensor are arranged inside the pressure-retaining cylinder, and respectively connected to the controller.

Abstract: A denoising optimization method for an AC traction motor by chamfering a stator tooth shoulder includes taking an angular vertex of the stator tooth shoulder as an end point, obtaining two points equidistantly along two sides of a stator tooth shoulder angle from the end point; and using the two points as tangent points D1 and D2 of the inscribed arc; making the inscribed arc of the tooth shoulder angle through the two tangent points D1 and D2, cutting off the tooth shoulder angle along the inscribed arc, and adjusting an oblique height HS1 of a stator tooth pole shoe. The invention obtains optimal values of a chamfering size and oblique height of a stator tooth slot pole shoe by adjusting the oblique height of the stator tooth pole shoe and adopting a particle swarm optimization algorithm.

Abstract: A friction and wear testing platform capable of simulating high-pressure, silt-containing and turbid submarine environment, including a tank, a loading device, a partition plate, a partition cylinder, a top sealing sleeve, a bottom sealing sleeve, a rotating shaft, an inner magnetic cylinder, an outer magnetic cylinder and a centering table. The partition plate and the partition cylinder divide an inner chamber of the tank into a test chamber and a pressure compensation chamber. The rotating shaft penetrates the pressure compensation chamber; two ends of the rotating shaft are sealed by the top and bottom sealing sleeves, respectively, as well as sealing bearings and rings therein. The loading device drives the rotating shaft to rotate, and the rotating shaft drives the inner magnetic cylinder to rotate. The centering table is driven through the magnetic coupling between the inner and outer magnetic cylinders to install a test piece.

Abstract: A device for reducing turn-off time of a transient electromagnetic transmitting signal includes a transmitting coil, a first electronic switch to control connection mode of the transmitting coil and a second electronic switch configured to form a bridge arm. The transmitting coil is a twisted pair including a first wire and a second wire. The first wire is connected to one end of the second electronic switch. The other end of the second electronic switch is connected to one end of the first electronic switch. The other end of the first electronic switch is connected to the second wire. The connection mode of the transmitting coil includes head-to-head connection, head-to-tail connection and tail-to-tail connection between the first wire and the second wire. The first wire and the second wire are connected to form a transmitting loop.

Abstract: A method for intelligent fault detection and location of a power distribution network is provided, which includes: constructing a network topology of the power distribution network, updating the network topology in real time to obtain an updated network topology, performing a fault identification based on the updated network topology, performing a fault locating based on the updated network topology to determine a fault node, and identifying a fault type based on a fault recorded signal of the fault node. With this method, fault locations and fault types of the power distribution network can be accurately detected in real time.

Abstract: A system for integratedly testing damping performance of a hydro-pneumatic suspension vehicle, including a testing platform and a testing device. The testing device includes a sensor module, a data acquiring and processing module and a testing software. A method for integratedly testing damping performance of a hydro-pneumatic suspension vehicle is also provided. A calculation is performed by a testing software to optimize a sensor configuration. A signal is acquired and transmitted by the sensor module. The signal is acquired and processed by a data acquiring and processing module, and displayed and analyzed by the testing software.

Abstract: An efficient ultra-precise shear thickening and chemical synergy polishing method, comprising the following steps: 1) fixing workpieces (3) to a polishing and fixing disc (31) of implementation equipment; 2) preparing an efficient ultra-precise shear thickening and chemical synergy polishing slurry, the polishing slurry comprising polishing abrasive particles or micro-powder, a shear thickening enhanced phase, water and green chemistry environmentally-friendly substances; 3) adding the prepared polishing slurry into a dust-prevention cover (30), and starting a polishing slurry circulating device, so that the polishing slurry is supplied to the surfaces of the workpieces (3) by means of polishing tools (1); and 4) starting driving devices (9) and driving mechanisms (33), so that the polishing tools (1) move relative to the workpieces (3), and surfaces of the workpieces (3) to be machined are polished.

Abstract: A horizontal drilling machine with an in-situ detection device, including a support frame, an armored cable, a steel pipe-straightening mechanism, a steel pipe-feeding mechanism, a motor, a power head, a drill pipe, a rotating chuck, a damper, a non-core drilling tool, the in-situ detection device, a fishing device and a thrust cylinder. The steel pipe-straightening mechanism, the steel pipe-feeding mechanism, the rotating chuck and the damper are sequentially fixed on the support frame from left to right. One end of the thrust cylinder is hinged with the support frame, and the other end is connected to the power head. The active drill pipe of the power head is connected to the drill pipe. An end of the armored cable is connected to the fishing device in the drill pipe, and the fishing head of the fishing device is connected to the spearhead of the non-core drilling tool.

Abstract: To solve the problem of large electromagnetic noise in AC traction motor, embodiments have open square notches at symmetrical positions on both sides of stator teeth of AC traction motor to effectively reduce electromagnetic noise without affecting other performance indicators of motor. In addition, embodiments fit the functional relationship between the optimal notch size or optimal slotting position size of motors and their power by determining the optimal notch size or optimal slotting position size of motors with different power grades, so as to achieve the noise reduction effect.

Abstract: A horizontal drilling machine with an impact device, including a support frame, an armored cable, a cable-straightening mechanism, a cable-feeding mechanism, a power head, a drill pipe, a rotating chuck, a damper, a fishing device with the impact device, a core tube and a thrust cylinder. One end of the thrust cylinder is hinged with the support frame, and the other end of the thrust cylinder is connected to the power head. The power head is arranged on a slid rail of the support frame. An active drill pipe of the power head is connected to the drill pipe. An end of the armored cable is connected to a control system, and the other end is connected to the fishing device in the drill pipe. A fishing head of the fishing device is connected to a spearhead of the core tube.

Abstract: A long-distance core drilling method suitable for a horizontal geological core drilling rig. (1) An active drill rod is connected to a drill rod, which is connected to a wireline-coring outer-tube drilling tool. (2) A steel-pipe string is connected to a fishing device, and the fishing device is connected to a spearhead on a core tube, which is placed to a designated position through a pipe-feeding mechanism. (3) A washing pump is started. (4) A core drilling is carried out. (5) A core is pulled out. (6) The steel-pipe string and the fishing device are reconnected. (7) The core tube is salvaged. (8) The core tube and drill pipe are replaced. (9) A hole is swept. (10) Steps (1)-(9) are repeated until the hole is drilled to a designated depth. (11) The core tube and the wireline-coring outer-tube drilling tool are recovered.

Abstract: A support device for the rotation of a high-capacity and compact drill pipe storage unit of a seabed drilling rig in a lying state, including: a rack, a plurality of curved support frames, a plurality of lateral drill pipe stoppers and a plurality of annular fences. The curved support frames are provided parallelly and coaxially on a slideway of the rack. A separating plate is provided on each of the curved support frames. A curved support surface of each of the curved support frames is in contact with a circular edge surface of the corresponding separating plate. The annular fences are mounted on the rack. Each of the annular fences is provided with a first gap and a second gap. The first gap is provided corresponding to the lateral drill pipe stopper. The second gap is configured to allow the drill pipes enter and exit the drill pipe storage unit.

Abstract: The present disclosure provides a portable seafloor drill rig for a submersible for multi-point core drilling, including a power head, a reduction gear box, an emergency jettison device, a drilling tool, and a temperature and pressure-retaining device. a water supply connector and the power head are arrange on a top plate of the reduction gear box. An output shaft of the power head is connected to an input shaft of the reduction gear box, and an output shaft of the reduction gear box is provided with a central hole, which is in communication with a water inlet hole of the water supply connector. An output shaft of the reduction gear box is connected to the emergency jettison device, and the temperature and pressure-retaining device can perform temperature and pressure-retaining storage of the core drilled by the drilling tool.

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.