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: Provided is a red mud-based composite calcium ferrite and a preparation method and use thereof. The preparation method of the red mud-based composite calcium ferrite includes the following steps: mixing red mud and a calcium source, and roasting an obtained mixture in an oxygen-containing atmosphere to obtain the red mud-based composite calcium ferrite; where the calcium source is selected from the group consisting of lime and calcium carbonate. In the present disclosure, the composite calcium ferrite is prepared using a solid waste red mud, with a greatly reduced cost of raw materials; on the other hand, compared with traditional calcium ferrite, the composite calcium ferrite mainly has phase structures of CaFe2O4, Ca2FeAlO5, and Ca2Fe2O5. Therefore, the composite calcium ferrite has a lower melting point, a higher lime dissolution efficiency, and better fluxing and dephosphorization effects during primary smelting and refining of molten steel, and has broad prospects for use in industry.

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.

Abstract: A petroleum drill-string shock absorber includes a drill collar nipple, a driving unit, an outer shell, a helical guideway, a drill bit base, a woven metal ring and a vibration-absorbing composite beam, the vibration-absorbing composite beam consists of a sheet metal and a flexible material gasket bonded by an adhesive; the drill collar nipple is connected with the helical guideway; the helical guideway is connected with the drill bit base; the driving unit rotates on the helical guideway; the outer shell is connected with the drill bit base; a metal seal ring is configured to seal a space formed between the outer shell and the drill collar nipple, a sealed space is formed among the drill collar nipple, the outer shell and the drill bit base; the woven metal ring is placed between the helical guideway and the drill bit base configured to absorb an axial impact vibration.

Abstract: A screw smelting machine melts raw materials with a different chemical ratio in a mixing funnel in a feeding order to prevent the long-range diffusion of a melt, and controls outflow at a suitable speed. A centrifugal casting machine solidifies the melt with the ingredients gradient varying into a radial ingredient gradient material by a centrifugal casting style. A temperature sensor monitors temperature of an outer surface of a centrifuge cavity of the centrifugal casting machine during centrifugal casting, and transmits the temperature to a control platform. The control platform determines an optimal flow rate of the melt at an end of screw rod according to ingredient gradient of ingredient radial-gradient pipe materials and a thickness of each component gradient material required with preparation, in combination with a real-time data fed back from the temperature sensor, and feeds back to a feeding end.

Abstract: Disclosed is a heating device, including a first and second ends of an indoor water supply pipe communicated with a main water supply pipe and a water supply end of a radiator; a valve, a first temperature sensor, a heating and control module and a third temperature sensor arranged between the first and second ends; two ends of the heating and control module connected with a bypass pipe; a first and second ends of an indoor return water pipe communicated with a main return water pipe and a return water end of the radiator; a three-way valve and a second temperature sensor arranged between the first end and the second end of the indoor return water pipe; and a first and second ends of the water pump communicated with a third end of the three-way valve and the indoor water supply pipe.

Abstract: A polishing method for an inner wall of a hollow metal part, including: firstly, placing a coaxial cathode in an inner hole of a metal part when a metal part model is designed, and printing the metal part model and the coaxial cathode together; then, sealing two ends of an inner hole cavity of the metal part by using a light curing part, fixing the coaxial cathode, filling the cavity with a polishing solution, and performing polishing treatment by using an electrochemical polishing method; and finally, reversing an electrode to break the coaxial cathode and take out the broken coaxial cathode to obtain a polished metal part.

Abstract: A method and system of robotic arm safety detection based on EtherCAT automation are provided. The method includes: issuing a control data through the protocol module to control the robotic arm to complete an automation operation process by the control system module, and receiving joint data fed back in real-time of the sensor module; acquiring a real-time data of the robotic arm by the data capture module; wherein the real-time data includes protocol data and joint data; the joint data is acquired by the data capture module through the sensor module; performing a protocol data rule matching and physical process detection by the intrusion detection module based on the real-time data, and obtaining an intrusion detection result; wherein the intrusion detection result is configured to detect whether an intrusion behavior occurs during a normal operation of the robotic arm.

Abstract: The present invention provides a high-strength and high-plasticity titanium matrix composite and a preparation method thereof. The preparation method includes: preparing high-oxygen hydride-dehydride titanium powder using a high-temperature rotary ball grinding treatment process, in which the prepared hydride-dehydride titanium powder has a particle size of 10-40 ?m, and has an oxygen content of 0.8-1.5 wt. %; preparing high-purity ultra-fine oxygen adsorbent powder using a wet grinding method of high-energy vibration ball grinding treatment process; in which a purity of the oxygen adsorbent powder is ?99.9%, and a particle size of the oxygen adsorbent powder is ?8 ?m; mixing the high-oxygen hydride-dehydride titanium powder with the oxygen adsorbent powder in a protective atmosphere, and then press-forming the powder obtained after mixing to obtain a raw material blank; and performing atmosphere protective sintering treatment on the raw material blank to obtain a titanium matrix composite.

Abstract: A method to achieve full densification and grain size control for sintering metal materials, wherein raw material powder is deagglomerated to obtain deagglomerated powder with dispersion. The deagglomerated powder is granulated by spray granulation. The granulated particles are processed by high-pressure die pressing and cold isostatic pressing. The powder compact is sintered by two-step pressureless sintering. The first step is to heat up the powder compact to a higher temperature and hold for a short time to obtain 75-85% theoretical density; the second step is to cool down powder compact to a lower temperature and hold for a long time. The two-step sintering can decrease the sintering temperature, so that the powder compact can be densified at a lower temperature. Thus, the obtained refractory metal product is densified, with ultrafine grains, uniform grain size distribution, and outstanding mechanical properties.

Abstract: A method of making steel by deeply dephosphorization in a hot metal tank and decarburization using semi-steel with nearly zero phosphorus load in a converter includes the following steps: putting an efficient dephosphorization agent into the hot metal tank in advance, and conducting dephosphorization during blast furnace tapping and transportation of blast furnace hot metal by the hot metal tank to obtain semi-steel with [P] less than 0.04 wt. % and [C] greater than or equal to 3.5 wt. %; and removing dephosphorization slag, and pouring the semi-steel into the converter for decarburization to obtain molten steel. The efficient dephosphorization agent includes iron oxide scale, lime, and composite calcium ferrite. According to the method, a phosphorus content of the blast furnace hot metal is reduced to be less than or equal to 0.04 wt. % through the efficient dephosphorization agent.

Abstract: A long-life service method for powder-bottom-injecting converter based on collaborative hot replacement of furnace bottom and bottom purging brick belongs to the field of steelmaking technologies using powder-bottom-injecting converters. According to equipment characteristics, process characteristics, and erosion characteristics of the powder-bottom-injecting converter, the design, arrangement, installation, use, maintenance, and replacement of the bottom purging/powder injection bricks are systematically optimized and improved, a technology of automatically detecting the erosion height of bottom purging bricks is adopted, and hot replacement of bottom purging/powder injection bricks and hot replacement of the converter furnace bottom are used collaboratively, which not only can prolong the service life of a single bottom purging/powder injection brick, but also can greatly prolong the overall life of the powder-bottom-injecting converter from 1000-3000 heats in the prior art to 6000-10000 heats.

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: A secondary cooling control method for reinforcing surface solidification structure of microalloyed steel continuous casting bloom includes: in situ observing precipitation behavior of secondary phase particles of the microalloyed steel, and determining a concentrated precipitation temperature range; cooling the microalloyed steel at different cooling rates, obtaining a particle size and a volume fraction of the secondary phase particles of the microalloyed steel at different cooling rates; determining an optimal average cooling rate; determining an optimal average cooling rate r; determining an optimal average cooling rate; and determining an optimal average cooling rate range through intersection of the three optimal average cooling rates whereby the continuous casting secondary cooling is optimized. The present invention can enhance the surface solidification structure of continuous casting bloom and reduce surface and subsurface cracks of the microalloyed steel continuous casting bloom.

Abstract: Disclosed is a metal-semiconductor contact structure based on two-dimensional (2D) semimetal electrodes, including a semiconductor module and a metal electrode module, where the semiconductor module is a 2D semiconductor material, and the metal electrode module is a 2D semimetal material with no dangling bonds on its surface; the 2D semiconductor material and the 2D semimetal material are interfaced with a Van der Waals interface with a surface roughness of 0.01-1 nanometer (nm) and no dangling bonds on the surface, the 2D semiconductor material and the 2D semimetal material are spaced less than 1 nm apart.

Abstract: A secondary cooling control method for reinforcing surface solidification structure of microalloyed steel continuous casting bloom includes: in situ observing precipitation behavior of secondary phase particles of the microalloyed steel, and determining a concentrated precipitation temperature range; cooling the microalloyed steel at different cooling rates, obtaining a particle size and a volume fraction of the secondary phase particles of the microalloyed steel at different cooling rates; determining an optimal average cooling rate; determining an optimal average cooling rate r; determining an optimal average cooling rate; and determining an optimal average cooling rate range through intersection of the three optimal average cooling rates whereby the continuous casting secondary cooling is optimized. The present invention can enhance the surface solidification structure of continuous casting bloom and reduce surface and subsurface cracks of the microalloyed steel continuous casting bloom.

Abstract: A selective laser melting technology-based apparatus for preparing a gradient material, comprising a laser scanning array lens, and a powder storer, a powder mixer, a powder scraping plate, and a working platform that are provided in sequence from top to bottom; the powder storer is provided with two or more partitions; a bottom portion of the powder storer is provided with an outlet; the powder mixer is provided under the powder storer and is a horizontally provided rotational mixer; the powder scraping plate is disposed under the powder mixer; the working platform is provided under the powder scraping plate; the laser scanning array lens is provided on the working platform. The present invention further relates to a method for preparing a gradient material, comprising powder storing, powder scraping, powder mixing, powder laying, and printing. The method can guarantee the two-phase powder ratio in each layer of powder not change.

Abstract: A method for preparing an oxygen-free passivated titanium or titanium-alloy powder product by means of gas-solid fluidization is provided.

Abstract: A pull cord type turning mechanism for a butterfly-inspired flapping-wing aerial robot includes a motor, a cord reel, a cord reel gear, a potentiometer gear, a potentiometer, a control module, and a power supply. The control module is connected to the motor and the potentiometer. A rotary shaft of the motor is connected to the cord reel, the cord reel is coaxially connected to the cord reel gear, the cord reel gear is meshed with the potentiometer gear, and the potentiometer gear is connected to a rotary shaft of the potentiometer. The cord reel gear is provided with two cord grooves and two pull cords. One ends of the two pull cords are fixed in the two cord grooves, respectively, and the other ends thereof are fixed at the tips of front wings of two sides of the butterfly-inspired flapping-wing aerial robot, respectively.