Abstract: The present invention discloses a closed circulation system for improving operating efficiency of a gas drainage pump. A liquid inlet of a pneumatic diaphragm pump is connected to a liquid outlet of a drag-reducing polymer solution tank, and a liquid outlet pipe of the pneumatic diaphragm pump leads to a circulation water pool. The drag-reducing polymer solution tank is provided with a pneumatic stirrer internally, and a charging hopper at the top. A liquid outlet of a submersible pump is connected to a liquid inlet of the drag-reducing polymer solution tank and a liquid inlet of a gas drainage pump respectively through a three way pipe, and a liquid discharge pipe of the gas drainage pump is connected to the circulation water pool. The pneumatic stirrer and the pneumatic diaphragm pump operate at high speeds.

Abstract: The present invention relates to a method for sorting and utilizing coal and rock for a coal and rock combined mining face, and is especially applicable to the sorting and utilization of coal and rock mined from a coal and rock combined mining face when an extremely thin coal seam is used as a protective layer in combined mining of multiple coal seams.

Abstract: Disclosed is a method using an environmental-friendly and artificial freezing technique for sealing and displacement of a soil pollutant. The method for displacement of the soil pollutant comprises: performing an artificial freezing technique on an area and depth of a surveyed contaminated site to form a sealed frozen wall along the perimeter of the contaminated site, by using the excellent permeation resistance function of the frozen wall to seal the contaminated site and to prevent the pollutant from spreading further; selecting a freezing temperature of ?10° C. to ?30° C. according to characteristics of the freezing temperature and precipitation rate of the pollutant, by controlling the freezing rate to 1 cm/day to 10 cm/day, and performing freezing displacement of the soil pollutant from outside to inside using a principle of freezing purification, to concentrate the pollutant; and subjecting the remaining high concentration of contaminated soil to chemical treatment.

Abstract: A device for stress-freezing experiments during fracturing process according to the present application, in which heating and cooling treatment on a specimen under corresponding temperature control according to a preset temperature gradient and a photosensitive curve is performed by a temperature control system, to realize stress-freezing of the specimen; a pressure is applied to a specimen by a true triaxial servo loading system; and corresponding fracturing experiments are performed to the specimen by a fracturing liquid pumping system having an output end arranged in a thermo-controlled oven.

Abstract: A quantitative evaluation method for the reliability of a Markov model switched reluctance motor system. The method comprises: solving a probability matrix P?T(t) of a switched reluctance motor system being in any survival state at any time t via a state conversion diagram of the switched reluctance motor system; calculating the sum of various elements of the probability matrix P?T(t) of the survival state, so that a reliability function R(t) is obtained; and thus calculating the average working time of the switched reluctance motor system before failure, thereby realizing the quantitative evaluation of the switched reluctance motor system and satisfying the requirements for the reliability analysis of a switched reluctance motor drive system. This disclosure has a good engineering application value.

Abstract: An apparatus for pre-loading a mechanical constant-resistance single prop includes a rhombic stretchable bracket, a screw rod, a first cylindrical sleeve ring, and a second cylindrical sleeve ring. The screw rod is connected to two opposite apex corners of the rhombic stretchable bracket. A tail end of the screw rod is fixedly connected to one apex corner of the rhombic stretchable bracket. An end head of the screw rod passes through another apex corner of the rhombic stretchable bracket. The remaining two opposite apex corners of the rhombic stretchable bracket are respectively fixedly connected to edges of the first cylindrical sleeve ring and the second cylindrical sleeve ring through connecting rods. The screw rod is threadedly connected to the apex corner of the rhombic stretchable bracket through which the screw rod passes. A method for pre-loading a mechanical constant-resistance single prop is also provided.

Abstract: A stampede preventing method for a pedestrian passage in a confined space of a subway. Pedestrian flow sensors are arranged on a pedestrian passage, where the pedestrian flow sensors are connected to a control unit by means of data transmission lines, the control unit is connected to stampede preventing devices and top ends of the stampede preventing devices are connected to movable walls and handrails; the pedestrian flow sensors transmit a pedestrian number and crowdedness that are monitored in real time; the control unit analyzes signals of the pedestrian flow sensors according to a system program, and determines whether crescent buffer space areas need to be opened in the pedestrian passage; the control unit issues different expansion commands according to different degrees of crowdedness; and the stampede preventing devices control the movable walls and the handrails to start contracting to form the crescent buffer space areas.

Abstract: A gas extraction method in which high energy gas fracturing technology is used to form a fracture network in a thermal injection borehole. Then high-pressure, cyclically temperature-changing steam is injected into the borehole using a spinning oscillating-pulse jet nozzle to form oscillating superheated steam, alternatingly impacting and heating the coal body. The high energy gas forms a fracture network that provides channels for passage of the superheated steam, while oscillating changes in steam temperature and pressure also promote crack propagation and perforation of the coal body; the combined effect of alternation of the two enhances gas desorption and extraction efficiency.

Abstract: A method for combining integrated drilling, flushing and slotting with thermal injection to enhance coalbed gas extraction, applicable to managing gas extraction from microporous, low-permeability, high-adsorption coalbed areas. A gas extraction borehole is drilled within a certain distance of a predetermined drilling, flushing and slotting borehole, and, once sealed, is used for gas extraction. An integrated drilling, flushing and slotting drill bit is used to sink the borehole, which is then sealed. Concentration variation in the gas extraction borehole is monitored in real time, and when concentration is below 30%, borehole is opened and high-temperature steam is injected by means of a steam generator, after which the borehole is again closed.

Abstract: A device for stress-freezing experiments during fracturing process according to the present application, in which heating and cooling treatment on a specimen under corresponding temperature control according to a preset temperature gradient and a photosensitive curve is performed by a temperature control system, to realize stress-freezing of the specimen; a pressure is applied to a specimen by a true triaxial servo loading system; and corresponding fracturing experiments are performed to the specimen by a fracturing liquid pumping system having an output end arranged in a thermo-controlled oven.

Abstract: A traction rope adjustment apparatus includes a traction rope pressing device, and a traction rope pulley apparatus. The traction rope lifting apparatus prevents the traction rope sagging, the traction rope pressing apparatus prevents the traction rope drifting, and the traction rope pulley apparatus enables a car and the counterweight to smoothly pass through the traction rope pressing apparatus, thereby implementing forced guidance of the traction rope and the reliable and smooth running of the car and counterweight. The apparatus can meet the demands of variable gradients and can implement reliable running of an inclined running container in variable gradients, such that the traction rope adapts to the different gradients, solving the challenge of the development of an inclined running container that self-adapts to gradients.

Abstract: The present invention discloses a process method for withdrawing and recovering a mechanical constant-resistance single prop, specific steps involving: detecting a working resistance and a degree of deformation of a mechanical constant-resistance single prop, releasing lug clamp bolts of a recoverable base, knocking a lower portion of a cylinder body of the mechanical constant-resistance single prop to disengage the mechanical constant-resistance single prop from the recoverable base, and dismantling the mechanical constant-resistance single prop. Parts are classified and recovered based on degree of deformation thereof. By means of the foregoing method, a process of withdrawing and recovering a mechanical constant-resistance single prop is standardized, simple and fast disengagement of the mechanical constant-resistance single prop is achieved, and parts that can still be used can be sufficiently recovered and reused, thereby achieving the objectives of saving energy and reducing costs.

Abstract: The present invention provides a self-drilling and self-anchoring extendable anchor rod applicable to soft and weak coal rocks and an anchoring method thereof, which are suitable for supporting soft and weak coal rock mass in roadways.

Abstract: A coal collapse column identification method and related apparatus that includes acquiring seismic shot gather data in a target region and a seismic wave migration velocity file; calculating a diffraction wave travel time of each piece of single-shot data at different imaging points according to the data; performing Mahalanobis distance calculation processing on each single-shot data and the diffraction wave travel time thereof to acquire a diffraction wave amplitude value sample point of each piece of single-shot data; imaging respectively on a diffraction wave of each piece of single-shot data; and superposing imaging processing results of all the single-shot data corresponding to the seismic shot gather data to obtain a diffraction wave imaging result of the seismic shot gather data so as to facilitate coal collapse column identification according to the diffraction wave imaging result. A diffraction wave corresponding to seismic shot gather data is extracted through a Mahalanobis distance.

Abstract: Disclosed is a method for designing supporting parameters of a transition support for a mixed mining face of filling and fully-mechanized mining.

Abstract: A shock-absorbing and energy-collecting roller cage shoe including a base, a main energy-collecting module, two auxiliary energy-collecting modules, and a roller is provided. The base is provided with three containing spaces for containing the main energy-collecting module and the two auxiliary energy-collecting modules. In the three containing spaces, the main energy-collecting module and the two auxiliary energy-collecting modules are respectively connected fixedly to the base through wire rope shock absorbers, the main energy-collecting module and the two auxiliary energy-collecting modules are respectively pressed on the left side, the upper side and the lower side of the roller, and the right side of the roller is pressed on a cage guide. The energy-collecting modules collect vibrational energy generated by vibration in the operation process of a lifting container, and convert the vibrational energy into collectable piezoelectric energy.

Abstract: A method and a device for detecting a discontinuous body with ground penetrating radar, comprising acquiring a ground penetrating radar signal of a predefined underground space, where the ground penetrating radar signal carries discontinuous information about an electrical parameter of the underground space; determining, from multiple preset dip angles, a target dip angle of the ground penetrating radar signal with respect to each of multiple channels to be scanned, by a target scanning algorithm; separating the ground penetrating radar signal according to the target dip angle, to obtain a scattered wave; performing velocity continuation analysis on the scattered wave, to obtain a focusing velocity of the scattered wave; and imaging the scattered wave according to the scattered wave and the focusing velocity, to obtain an imaging result, where the imaging result is used to determine distribution information of the discontinuous body in the predefined underground space.

Abstract: A method for constructing networked preferential gas migration pathways and diverting and extracting gas. The method proposes that a fracture generation hole, a fracture guidance and development hole, a lateral rupture hole, and a fracture connection hole are respectively constructed in a roof in roadways on two sides of a working face in advance of an advance stress change area. Artificial guided fractures are actively constructed and formed inside the hard roof. Under a mining-induced stress effect, the artificial guided fractures and mining-induced fractures intersect with and are connected to each other to form networked preferential gas migration pathways. Meanwhile, boreholes for artificial guided fractures accelerate roof fracturing to form a rupture bed separation fracture area in a roof. Gas flows and migrates in a timely and efficient manner along networked fracture pathways and concentrates in the rupture bed separation fracture area in the roof.

Abstract: A method for stepwise construction of a preferential gas migration pathway at a stope in a coal seam. First, a gas migration pathway is preliminarily formed at a stope depending on a mining effect of mining in a first mined seam. construction and stabilization method of gob-side entry retaining in deep strata, and a method of manual-guided pre-fracturing boreholes are then used to perform active construction respectively in external space and the outside of coal-rock mass to form preferential gas migration pathways. Eventually, under the effect of mining-induced stress, a system of preferential gas migration pathways connected to each other at the stope is further formed.

Abstract: Systems and methods for detecting a layer-to-layer transition of a lifting steel wire rope on a reel are described. The system includes a reel assembly for winding a steel wire rope on a reel and a tensioning assembly for tensioning a segment of said steel wire rope. The system further includes a loading assembly and a lead screw sliding assembly. The loading assembly provides a vertical loading to the tensioning assembly so as to generate a loading force between the tensioned steel wire rope and the steel wire rope wound around the reel. The lead screw sliding assembly drives the tensioning assembly so as to move on a horizontal guide rail to generate a relative displacement between the tensioned steel wire rope and the steel wire rope wound around the reel. The tensioning assembly is connected to the loading assembly via a first threaded rod and a static torque sensor.