Abstract: A device and a method for nondestructively detecting a transient characteristic of a conductive screw of a turbo-generator rotor are provided. The device includes a personal computer (PC), an extremely-steep pulse generator, an ultra-high-frequency double-isolation transformer, and a pulse emitting and coupling module, which are connected in sequence. The pulse emitting and coupling module is connected to a load. A synchronous pulse receiving non-inductive divider circuit synchronously receives a characteristic waveform from the load, and the synchronous pulse receiving non-inductive divider circuit is connected to an ultra-high-speed analog/digital (A/D) module through a nonlinear saturation amplifying circuit that amplifies a signal. The PC receives a signal from the ultra-high-speed A/D module. The load includes a positive or negative excitation lead loop that is in a 180° symmetrical and instantaneous short-circuit state and a rotor shaft.

Abstract: A device for detecting a slot wedge, an air gap and a broken rotor bar is provided, where a sequential circuit generates double concurrent pulses; the sequential circuit is connected to driving power modules; the driving power modules are connected to front-end interface circuits; the front-end interface circuits convert the double concurrent pulses into corresponding magnetic-field pulses; the magnetic-field pulses are transmitted to power supply terminals on adjacent phases of stator windings through impedance matching pins and coupled at a corresponding coil, air gap and squirrel cage rotor to generate single groups of cyclic rotating magnetic potentials; single rotating magnetic potentials are sequentially generated in adjacent slots on each of the phases of the stator windings; rotating electric potentials in magnetic circuits with two symmetrical phases are magnetically coupled to form distributed coupling magnetic field reflected full-cycle waves for reflecting a difference of a corresponding slot wedg

Abstract: An intelligent vehicle capturing apparatus for a high-pier bridge includes: a double-layer metal protective net, support unit and actuation unit connected thereto. The protective net mounts to a high-pier bridge backside through the support unit. The actuation unit includes a hydraulic link mechanism connected to one end of the protective net. The hydraulic link mechanism unwinds the protective net to capture a vehicle. The apparatus stops a vehicle rushing off a high-pier bridge. Upon completion, a hydraulic system drives a third hydraulic cylinder in a support rod on the high-pier bridge backside driving a rolling shaft rotating, winding and placing a protective net on the high-pier bridge backside. The apparatus has a simple structure, is practical and easily used, useful on hazardous high-pier bridges protecting vehicle passengers and avoiding traffic accidents resulting from vehicles rushing out of the high-pier bridges.

Abstract: A magnetic tag sensor includes a cylinder and threaded pipe embedded therein and simulates a magnetic dipole; two threaded pipe wiring interfaces being connected to first and second cables, running through a cylinder upper cross-section outer wall and extending out of the cylinder; the cylinder is sleeved on a guide rail and at a junction between a riverbed and water; an guide rail end inserts into the riverbed, a water sealing box is mounted on a top of the guide rail, a power supply module, a relay and a load arranged inside the water sealing box, the first cable connected to a positive pole of the power supply module, and the second cable connected to a negative pole through the relay and load connected in series; and the threaded pipe in the wall of the cylinder moves up and down with the riverbed to generate a magnetic field signal.

Abstract: The present invention discloses a foam material for fire prevention and extinguishing and a preparation method and a use thereof. The foam material for fire prevention and extinguishing comprises the following raw materials in parts by weight: 2-4 parts of foaming agent, 2.5-3.5 parts of foam stabilizer, 10-16 parts of expandable graphite, and 100 parts of water. The foam material for fire prevention and extinguishing has a foaming multiple up to 15-30 times, a viscosity of only 700 mPa·s at a flow state, and the foam could be stable for more than 12 h. After being transported to an ignition point of the goaf via the mine grouting pipeline, the foam material for fire prevention and extinguishing can spread and pile in a large area in the goaf, and thus cover and plug the float coal at low and high places, with a piling height above 1.5 m.

Abstract: A magnetic tag sensor includes a cylinder and threaded pipe embedded therein and simulates a magnetic dipole; two threaded pipe wiring interfaces being connected to first and second cables, running through a cylinder upper cross-section outer wall and extending out of the cylinder; the cylinder is sleeved on a guide rail and at a junction between a riverbed and water; an guide rail end inserts into the riverbed, a water sealing box is mounted on a top of the guide rail, a power supply module, a relay and a load arranged inside the water sealing box, the first cable connected to a positive pole of the power supply module, and the second cable connected to a negative pole through the relay and load connected in series; and the threaded pipe in the wall of the cylinder moves up and down with the riverbed to generate a magnetic field signal.

Abstract: The present invention discloses a foam material for fire prevention and extinguishing and a preparation method and a use thereof. The foam material for fire prevention and extinguishing comprises the following raw materials in parts by weight: 2-4 parts of foaming agent, 2.5-3.5 parts of foam stabilizer, 10-16 parts of expandable graphite, and 100 parts of water. The foam material for fire prevention and extinguishing has a foaming multiple up to 15-30 times, a viscosity of only 700 mPa·s at a flow state, and the foam could be stable for more than 12 h. After being transported to an ignition point of the goaf via the mine grouting pipeline, the foam material for fire prevention and extinguishing can spread and pile in a large area in the goaf, and thus cover and plug the float coal at low and high places, with a piling height above 1.5 m.