Abstract: The present disclosure provides a coal bump control method for sectional hydraulic fracturing regions of a near vertical ultra thick coal seam. The method includes: deepening a main shaft from a mining level to a fracturing level; excavating a cross-hole from a roof rock layer of a coal seam at the fracturing level to enter a coal seam being mined, and excavating a roadway along the strike of the coal seam; and drilling hydraulic fracturing boreholes in a dedicated fracturing roadway along an inclination angle of the coal seam to the coal seam above the roadway, wherein the length of the borehole makes the borehole in communication with a goaf, and the spacing of the boreholes along the strike and the sectional spacing of the boreholes in an inclination direction are designed according to the parameters of fracturing equipments and the fracturing length.

Abstract: An efficient blasting method for similar cutting in a rock tunnel is provided, which relates to the technical field of rock tunneling. The method includes the following steps: drilling: drilling central holes, lower cutting holes, upper cutting holes, auxiliary holes and peripheral holes in a cross section area for tunnel construction; filling explosives: filling explosives into the central holes, the lower cutting holes, the upper cutting holes, the auxiliary holes and the peripheral holes; and blasting: blasting following blast holes in turn to complete full-face one-time blasting in a millisecond delay blasting mode. The method is applicable for construction scenes of drilling and blasting methods.

Abstract: A method for numerical reconstruction and heat transfer characteristics evaluation of a microstructure of thermal barrier coatings containing microcracks includes the following steps: determining a simulation area and size settings, generating random microcracks with different morphological characteristics and placing the microcracks in the simulation area, and determining whether a space occupied by the microcracks reaches a porosity ratio of the preset microcracks, building a general pore model of thermal barrier coatings (TBCs) based on the QSGS method, reconstructing true mesoscopic morphologies of the TBCs, determining whether the preset volume fraction has been reached, and building a heat transfer analysis model based on the thermal 1,attice Boltzmann method to calculate heat insulation performance parameters such as temperature distribution, and thermal conductivity.

Abstract: A low-carbon and low alloy hot-work die steel with a high toughness at low temperatures and a high strength at high temperatures and a high hardenability, comprises the following components: C: 0.15-0.35%, Si: 0.40-0.90%, Mn: ?0.80%, Cr: 1.50-2.40%, Ni: 2.50-4.50%, Mo: 1.00-1.60%, V: 0.10-0.40%, W: 0.20-0.90%, P: ?0.02%, S?0.02%, and a balance of Fe matrix and other inevitable impurities. The above percentages are mass percentages. The material of the present invention can have a V notch impact energy of 30 J or more than 30 J at ?40° C., a high temperature strength of 380 MPa or more at 700° C., and a hardenability of 200 mm or more to ensure the consistency of internal and external microstructures. The materials of the present invention can be applied to hot-work molds used in special working conditions that require high toughness at low temperatures, high strength at high temperatures and high hardenability.

Abstract: In the field of photoelectric devices, a visible light detector is provided with high-photoresponse based on a TiO2/MoS2 heterojunction and a preparation method thereof. The detector, based on a back-gated field-effect transistor based on MoS2, includes a MoS2 channel, a TiO2 modification layer, a SiO2 dielectric layer, Au source/drain electrodes and a Si gate electrode, The TiO2 modification layer is modified on the surface of the MoS2 channel. By employing micromechanical exfoliation and site-specific transfer of electrodes, the method is intended to prepare a detector by constructing a back-gated few-layer field-effect transistor based on MoS2, depositing Ti on the channel surface, and natural oxidation.

Abstract: The present disclosure relates to a three-degree-of-freedom convenient mobile powder recovery device and a recovery method. The three-degree-of-freedom convenient mobile powder recovery device includes: a powder recovery module, a three-degree-of-freedom adjusting module and a drying and sieving module, wherein the powder recovery module is arranged on the three-degree-of-freedom adjusting module and used to recover powder; and the drying and sieving module is arranged on the three-degree-of-freedom adjusting module, connected to the powder recovery module and used to dry and sieve powder recovered by the powder recovery module. The three-degree-of-freedom convenient mobile powder recovery device has a simple structure, which is convenient to be operated. The height and position of the three-degree-of-freedom convenient mobile powder recovery device can be adjusted automatically, so that the recovery device is suitable for the setting of laser processing systems with various heights in the telescopic range.

Abstract: An Artificial Intelligence (AI) engine-supporting downlink radio resource scheduling method and apparatus are provided. The AI engine-supporting downlink radio resource scheduling method includes: constructing an AI engine, establishing a Socket connection between an AI engine and an Open Air Interface (OAI) system, and configuring the AI engine into an OAI running environment to utilize the AI engine to replace a Round-Robin scheduling algorithm and a fair Round-Robin scheduling algorithm adopted by a Long Term Evolution (LTE) at a Media Access Control (MAC) layer in the OAI system for resource scheduling to take over a downlink radio resource scheduling process; sending scheduling information to the AI engine through Socket during the downlink radio resource scheduling process of the OAI system; and utilizing the AI engine to carry out resource allocation according to the scheduling information, and returning a resource allocation result to the OAI system.

Abstract: The present disclosure provides a method and device for intelligent control of heating furnace combustion based on a big data cloud platform, which relates to the technical field of artificial intelligence control. The method includes: construction of big data cloud platform based on production and operation parameters of the heating furnace; identification of key factors in the production process of the heating furnace by using big data mining technology; independent deployment of traditional heating furnace combustion control systems based on the mechanism model; and integration of cloud platform big data expert knowledge base and the heating furnace combustion intelligent control system.

Abstract: A full-face shaft tunnel boring machine system includes a tunnel boring machine cutterhead device for tunneling downwards in a shaft; a full-hydraulic formwork device for supporting and walling in a wellbore; and an upper muck-discharge system for vertically conveying rock mucks generated by tunneling. The tunnel boring machine cutterhead device comprises a vertical guide frame, a cutter-expanded boring head and an advanced cutterhead that are fixedly connected in a vertical order from top to bottom so as to form an integrated structure. The vertical guide frame is a hollow cylindrical structure and driven to rotate around an axis of the vertical guide frame by a power mechanism, and an outer wall of the vertical guide frame is provided with multiple sets of first guide rollers.

Abstract: A method of preparation of titanium and titanium alloy powder for 3D printing is based on a fluidized bed jet milling technique. Hydride-dehydrite titanium powder and titanium alloy powder are used as main raw material powder, jet milling and shaping are carried out in shielding atmosphere of nitrogen or argon, and finally high-performance titanium and titanium alloy powder meeting the requirements of 3D printing process is obtained. The titanium and titanium alloy powder prepared using this method has a narrow particle size distribution, approximately spherical shape, and controllable oxygen content.

Abstract: The invention is in the field of iron and steel metallurgy, specifically a method and system for determining the amount of alloy added during the converter tapping process. Given that the LSTM neural network has a strong ability to capture nonlinear relationships, the invention builds an alloy element yield prediction model based on the LSTM neural network. Because different alloy elements have different factors that affect their yield, that is, different model input variables, different LSTM models are established for training. Furthermore, the invention uses integer linear programming to combine the yield prediction results to determine the alloy addition amount. This method not only finds the optimal alloy proportioning scheme quickly, but it also improves the component hit rate and the stability of steel products in the converter steelmaking process, obtains the lowest total cost, effectively reduces alloying costs, and has a good application prospect.

Abstract: A device and method for preparing a low-impurity regenerated brass alloy through step-by-step insertion of an electrode are provided. The device includes a melt heating apparatus, an electrode displacement apparatus, and a pulse current generation apparatus. The automatic electrode lifting apparatus is controlled to adjust an insertion depth of the graphite electrode plate in the metal melt, and the pulse current generation apparatus is controlled to adjust the parameters of pulse current to achieve the impurity reduction on the metal melt. The preparation of a low-impurity regenerated brass alloy involves a short production process, simple operations, low energy consumption, and high impurity removal efficiency, and is suitable for regeneration and large-scale continuous production of non-ferrous metal alloys.

Abstract: A full-face shaft tunnel boring machine system includes a tunnel boring machine cutterhead device for tunneling downwards in a shaft; a full-hydraulic formwork device for supporting and walling in a wellbore; and an upper muck-discharge system for vertically conveying rock mucks generated by tunneling. The tunnel boring machine cutterhead device comprises a vertical guide frame, a cutter-expanded boring head and an advanced cutterhead that are fixedly connected in a vertical order from top to bottom so as to form an integrated structure. The vertical guide frame is a hollow cylindrical structure and driven to rotate around an axis of the vertical guide frame by a power mechanism, and an outer wall of the vertical guide frame is provided with multiple sets of first guide rollers.

Abstract: Disclosed are a high strength-ductility matched oxide-particles dispersion steel, a preparation method and application thereof, belonging to the technical field of novel structural materials. The high strength-ductility matched oxide-particles dispersion steel comprises the following components in percentage by mass: chromium (Cr) 11.0-13.0 percent (%), tungsten (W) 1.0-2.0%, vanadium (V) 0.1-0.2%, yttrium (Y) 0.3-0.4%, oxygen (O) 0.05-0.15%, silicon (Si) 1.5-2.5%, carbon (C) ?0.0016%, with iron (Fe) and unavoidable impurities accounting for a rest. The high strength-ductility matched oxide-particles dispersion steel in the present application is prepared, using a powder metallurgical preparation method, by introducing high-content of silicon elements and introducing high-density oxide particles with a complete core-shell structure using a specific heat treatment regime.

Abstract: A method of locating a failure of coal-rock-concrete based on vector features of a near-field electromagnetic field is provided. The method senses and records the real electromagnetic field vector information in space by arranging a triaxial electromagnetic sensor array around a coal-rock-concrete body, and realizes the localization of the failure areas of the coal-rock-concrete body by establishing an electromagnetic radiation localization model for the failures of the coal-rock concrete body.

Abstract: The present disclosure relates to a fiber-reinforced copper-based brake pad for high-speed railway train, and preparation and friction braking performance thereof. The fiber-reinforced copper-based brake pad for high-speed railway train comprises 80-98.5 wt. % metal powder, 1-15 wt. % non-metal powder and 0.5-5 wt. % fiber component. In addition, some components are added in a specific proportion to achieve optimal performance. The copper-based powder metallurgy brake pad is obtained by powder mixing, cold-pressing and sintering with constant pressure. The friction braking performance of the obtained brake pad is tested according to a braking procedure consisting of three stages, i.e., the first stage with low-pressure and low-speed, the second stage with high-pressure high-speed and the continuous emergency braking third stage with high-pressure and high-speed.

Abstract: A vacuum solution and aging treatment process for improving high-temperature plasticity of GH4738 rings includes: heating a GH4738 ring to 1020° C. to 1030° C. in a vacuum environment; injecting nitrogen; subjecting the GH4738 ring to aging treatment at 740° C. to 750° C.; and taking out and air-cooling the GH4738 ring. The method realizes the uniform distribution of the intragranular ?? precipitates and the intergranular M23C6 carbides in the GH4738 ring after heat treatment. The elongation and area reduction of the alloy ring stretched at 540° C. after heat treatment are 30% and 34% respectively, which are 25% and 36% higher than those before process optimization respectively; and that at 760° C. are 49% and 70% respectively, which are 32% and 27% higher than those before process optimization respectively. The index requirements can be fully met. This process is applicable to GH4738 rings, which have a high requirement on high-temperature plasticity after heat treatment.

Abstract: The present disclosure provides a converter CO2—O2 mixed injection smelting method and a fire point area temperature dynamic control method. The method realizes online monitoring through an infrared temperature sensor installed inside an oxygen lance, dynamically adjusts the mixing ratio of CO2 and O2 and the height of the oxygen lance position according to the fire point area temperature changes and process requirements in different smelting stages, so that the secondary smelting system interlockingly and dynamically controls the fire point area temperature and the molten pool heating rate.

Abstract: A method and system for predicting post-earthquake repair of building groups in community are provided. The method includes: obtaining seismic damage states, building functions, and building areas of building groups in the community; determining a repair priority of each building based on functional classifications of the buildings; calculating a building repair workload considering the seismic damage states and building areas of the building groups in the community, and developing an individual-building repair model for simulating the repair process of an individual building under certain resource conditions; and developing a community building group repair resource allocation model and a community building group repair system dynamics model to predict the repair process of the building groups in the community at different levels of resource availability. The technical solution of the present invention can simulate the post-earthquake repair process of the building groups in the community.

Abstract: A segmented grouting method for ramp drivage in an aquifer is provided. Concerning grouting reinforcement for a ramp in an aquifer, a grouting process is divided into four stages according to a pressure change, that is, micro-pressure filling, low-pressure diffusion, medium-pressure reinforcement, and high-pressure fracturing. In the micro-pressure filling, an initial pressure of a grouting orifice is 0, and a low-concentration single-component grout is used to fill an original fissure of the aquifer. In the low-pressure diffusion, a low-concentration bicomponent grout is used for grouting, the original fissure is expanded, and a grouting radius is increased. In the medium-pressure reinforcement, a high-concentration bicomponent grout is used for grouting, thereby reinforcing the aquifer. In the high-pressure fracturing, a high-concentration bicomponent grout is used to reinforce a new fractured fissure of the orifice caused by a high pressure and the original fissure, thereby forming a confining bed.