Abstract: Disclosed is a method for designing parameters of an advance stress relief hole in a rockburst source zone of a construction tunnel in deep-seated hard rocks, including S1: classifying rockbursts in the TBM tunnel in the deep-seated hard rocks; S2: identifying a potential rockburst source zone of the TBM tunnel in the deep-seated hard rocks; S3: developing a scheme design and effect evaluation method for the parameters of the advance stress relief hole; S4: performing analysis to find a pattern in the parameters of the advance stress relief hole and optimizing the design; and S5: determining an optimal scheme for arranging the stress relief hole in accord with engineering practice.

Abstract: A single-motor electrically powered bed includes: a bed board, a frame, a slide assembly, a first connecting-rod mechanism, and a drive assembly; the bed board includes: a first bed board and a second bed board, one end of the first bed board being hingedly connected to one end of the second bed board; the second bed board is slidably connected to the frame by means of the slide component, the two ends of the first connecting-rod mechanism are hingedly connected to the first bed board and the frame, respectively, and the first bed board can be raised and lowered by means of the drive assembly. The single-motor electrically powered bed needs only one drive assembly to drive all of the bed boards to move, adjust the position and height of the human body, and achieve the lifting and lowering function of the electrically powered bed.

Abstract: A control method for vehicle-mounted video and audio playback includes in response to activation of an vehicle-mounted video and audio mode, obtaining facial data of at least one user outside a vehicle, determining a pose parameter of a projection screen according to the facial data of the at least one user, adjusting a pose of the projection screen based on the pose parameter, controlling an vehicle-mounted projection device to project video data of video and audio data onto the projection screen, and controlling an vehicle-mounted external speaker to synchronously broadcast audio data of the video and audio data. The projection screen is integrated into a rear trunk door of the vehicle, and the rear trunk door is open, and the projection screen is in an expanded state in the vehicle-mounted video and audio mode.

Abstract: Disclosed are a multi-scale photoacoustic detection method of geological structure around a borehole and related devices. The method includes: obtaining depth information and direction information of the borehole; generating trajectory data of the borehole according to the depth information and direction information; obtaining an optical image of the geological structure around the borehole; generating a first velocity model according to the optical image and the trajectory data; obtaining low-frequency acoustic wave data and high-frequency acoustic wave data of the geological structure around the borehole; performing a full waveform inversion on the first velocity model according to the low-frequency acoustic wave data and the high-frequency acoustic wave data to obtain a second velocity model; and determining the geological structure around the borehole according to the second velocity model.

Abstract: The embodiment of the present application discloses a method and equipment for transformation of point cloud coordinates of structure plane of deep-buried tunnel based on a target device. Before performing laser scanning on a measured surface, the embodiment of the present application makes the third plate surface close to the measured surface by adjusting the target device, and makes the bubbles of the first circular level and the second circular level in a centered state; respectively extracting point cloud coordinates of the three cross targets from the point cloud data, and acquiring the first tendency of the third plate surface from the digital display of three-dimensional electronic compass; determining the second tendency of the third plate surface according to the point cloud coordinates; converting the coordinates in the point cloud data to geodetic coordinates according to the first tendency and the second tendency.

Abstract: A dual channel nondestructive testing method for a rock bolt and related devices includes: determining a target phase difference and an instantaneous phase difference of the first received signal and the second received signal; determining an integral instantaneous phase difference between the first received signal and the second received signal based on the target phase difference and an instantaneous phase difference; determining a length of the exposed section of the rock bolt, a length of the rock bolt and a position of a grouting defect based on the integral instantaneous phase difference, a first velocity of the acoustic signal propagating in an exposed section of the rock bolt and a second velocity of the acoustic signal propagating in an anchor section of the rock bolt.

Abstract: The present disclosure provides a thermal insulation apparatus and a crucible production device. The thermal insulation apparatus is configured for supporting a mold, and includes: a housing, a first flange, a second flange and a plurality of reinforcing members, and the housing, the first flange and the second flange are coaxially arranged. An inner wall of the housing is enclosed to form an accommodating cavity, and the accommodating cavity is configured for accommodating the mold; a water-cooling cavity is enclosed between the inner wall and an outer wall of the housing; the first flange is connected to a top portion of the housing, so as to fix an upper edge of the mold to the top portion of the housing; the second flange is connected to a bottom portion of the housing; and the plurality of reinforcing members are arranged between the bottom portion of housing and second flange.

Abstract: A stereoscopic identification method and apparatus for disturbance stress evolution process of underground cave surrounding rock perform a numerical inverse analysis of three-dimensional stereoscopic disturbance stress of a surrounding rock of the target underground cave on the basis of measurement values of three-component microseismometers and disturbance stress gauges. During the analysis, the overall prediction values are corrected from point to volume based on the measurement values to achieve a high-precision identification effect of the evolution process of the stereoscopic disturbance stress of the surrounding rock.

Abstract: The embodiment of the present application discloses a method and equipment for transformation of point cloud coordinates of structure plane of deep-buried tunnel based on a target device. Before performing laser scanning on a measured surface, the embodiment of the present application makes the third plate surface close to the measured surface by adjusting the target device, and makes the bubbles of the first circular level and the second circular level in a centered state; respectively extracting point cloud coordinates of the three cross targets from the point cloud data, and acquiring the first tendency of the third plate surface from the digital display of three-dimensional electronic compass; determining the second tendency of the third plate surface according to the point cloud coordinates; converting the coordinates in the point cloud data to geodetic coordinates according to the first tendency and the second tendency.

Abstract: The present application provides a quantitative assessment method, apparatus and device for global stability of surrounding rocks of underground caverns, which are configured to provide a concrete, practical and effective quantitative assessment solution for a global stability state of the surrounding rocks of the underground caverns. The quantitative assessment method for global stability of surrounding rocks of underground caverns includes: extracting, after determining an assessment task for the global stability of the surrounding rock of a target underground cavern, initial data of the target underground cavern; dividing, according to the initial data, the target underground cavern into different independent cavern units or cavern sections; and rating, according to a preset stability assessment strategy, the eight factors influencing the stability of surrounding rocks of cavern units or the cavern sections are rated respectively, as a global stability assessment result of the target underground cavern.

Abstract: The present application provides a quantitative assessment method, apparatus and device for global stability of surrounding rocks of underground caverns, which are configured to provide a concrete, practical and effective quantitative assessment solution for a global stability state of the surrounding rocks of the underground caverns. The quantitative assessment method for global stability of surrounding rocks of underground caverns includes: extracting, after determining an assessment task for the global stability of the surrounding rock of a target underground cavern, initial data of the target underground cavern; dividing, according to the initial data, the target underground cavern into different independent cavern units or cavern sections; and rating, according to a preset stability assessment strategy, the eight factors influencing the stability of surrounding rocks of cavern units or the cavern sections are rated respectively, as a global stability assessment result of the target underground cavern.

Abstract: Disclosed is a dual channel nondestructive testing method for a rock bolt and related devices. The method includes: determining a target phase difference and an instantaneous phase difference of the first received signal and the second received signal; determining an integral instantaneous phase difference between the first received signal and the second received signal based on the target phase difference and an instantaneous phase difference; determining a length of the exposed section of the rock bolt, a length of the rock bolt and a position of a grouting defect based on the integral instantaneous phase difference, a first velocity of the acoustic signal propagating in an exposed section of the rock bolt and a second velocity of the acoustic signal propagating in an anchor section of the rock bolt.

Abstract: Disclosed are a multi-scale photoacoustic detection method of geological structure around a borehole and related devices. The method includes: obtaining depth information and direction information of the borehole; generating trajectory data of the borehole according to the depth information and direction information; obtaining an optical image of the geological structure around the borehole; generating a first velocity model according to the optical image and the trajectory data; obtaining low-frequency acoustic wave data and high-frequency acoustic wave data of the geological structure around the borehole; performing a full waveform inversion on the first velocity model according to the low-frequency acoustic wave data and the high-frequency acoustic wave data to obtain a second velocity model; and determining the geological structure around the borehole according to the second velocity model.

Abstract: A bed frame includes: an external frame, an internal supporting portion and a bed cover. The external frame is a hollow frame. The internal supporting portion is of a large-interval structure. The internal supporting portion is arranged inside the external frame (1) to reinforce the strength of the external frame. The bed cover covers the top faces of the external frame and the internal supporting portion to form a flat bed surface.