Abstract: The present disclosure provides a method for controlling an amount of silicon added to ductile cast iron, a method for casting ductile cast iron, and a cast product, which relate to the technical fields of metallurgical and cast iron alloys. The method for controlling an amount of silicon added to ductile cast iron includes smelting ductile cast iron using scrap steel as a raw material. After the scrap steel is melted into molten iron, a copper alloy is added so that the molten iron has a copper equivalent of 0.8% to 1.0%, wherein the copper equivalent is controlled by formula (II). Then, ferrosilicon is added so that the content of silicon added to the molten iron satisfies formula (I).

Abstract: An on-line measurement-error correction device and method for the inner profile of a special-shaped shell, including a fixing device. A vertical moving device is fixed at the top of the fixing device and connected with a horizontal moving device connected with a distance monitoring device, which is movable vertically and horizontally under the drive of the vertical and horizontal moving devices. The distance monitoring device includes a displacement monitoring element fixedly arranged on a fixing support hinged with an electric push rod configured to displace to drive the displacement monitoring element to deflect so as to change a monitoring direction. The displacement monitoring element is driven to deflect by the electric push rod of the distance monitoring device to change a monitoring direction, and a distance between each longitudinal section surface point on the inner surface of the special-shaped shell and the displacement monitoring element can be gradually measured.

Abstract: A system and method deliver fluidized powder based on flue gas carrying waste slag and instant cooling steel slag. A first flue gas pipeline receives pressurized CO2-rich flue gas and in fluid communication with a fluidization air pipeline, a pressurization air pipeline and a supplementary air pipeline respectively and through them enters an upper discharge bin; a second flue gas pipeline receives the pressurized CO2-rich flue gas and in fluid communication with a gas-gas mixer, a dense phase discharge guide pipe first end extends into the upper discharge bin and receives high-pressure dense phase gas-powder flow of CO2-rich flue gas, and a dense phase discharge guide pipe second end is connected to the gas-gas mixer; a variable-pitch twin screw sealed conveyor discharge end extends into an upper discharge bin internal space, and is provided with an upwardly inclined gas-blocking segment.

Abstract: An active edge caching method based on community discovery and weighted federated learning for selecting an optimal caching user and developing an optimal caching strategy; user grouping method based on community discovery is first provided, users are divided into different user groups according to users' mobility and social attributes, degrees of importance of different users are computed in each user group, and most important user is selected as a caching node to provide content distribution services; a content popularity prediction framework based on attention weighted federated learning is provided for combining attention weighted federated learning mechanism with deep learning algorithm to predict future user preferences for different content, so as to improve content popularity prediction accuracy and solve user privacy disclosure; finally, hot content is cached on selected caching users according to prediction results, to achieve goals of reducing network transmission latency and network operation cost

Abstract: A method and system of positive and negative sequence rotor currents control for DFIG-WTs under a single dq-PI control structure includes: adjusting the negative sequence rotor current reference according to the negative sequence stator terminal voltage to obtain a reference adjustment value; converting the reference adjustment value to the forward-rotating dq coordinate system and superimposing it with the positive sequence rotor current reference as the input of a PI-regulator-based current feedback controller to uniformly control the positive and negative sequence rotor current; determining the output voltage reference of the rotor-side converter by the PI-regulator-based current feedback controller, according to which, the switching signal of the rotor-side converter can be determined through the SPWM function, controlling the turn-on and turn-off of the bridge arms of the rotor-side converter to form the output voltage.

Abstract: A hydraulic actuator with no friction and zero leakage and its drive system are provided. The hydraulic actuator includes a thickened disc structure A and a thickened disc structure B. The second end face of the thickened disc structure A is connected with the first end face of the thickened disc structure B, and a control cavity is formed between the second end face of the thickened disc structure A and the first end face of the thickened disc structure B. The drive oil access hole is arranged on the thickened disc structure B, and the control cavity is connected with the drive oil access hole. The displacement output method based on elastic deformation is adopted, which completely avoids the nonlinear phenomena such as leakage and friction, and reduces the difficulty of high-precision control of the actuator.

Abstract: A dynamic loose vehicle formation method based on real-time online navigation map, which belongs to the field of vehicle formation technologies. The method includes a driver inputs travel information of a destination and waypoints in a GIS app; the GIS app uploads the travel information to a GIS server; the driver chooses to join a recommended formation or create a formation in the GIS app; when the driver chooses the formation and joins the formation, the formation information is displayed on the GIS app interface and sent to other vehicles within the formation for information interaction; when the driver chooses to leave the formation and leaves the formation, the formation is adjusted and the GIS server updates the formation information.

Abstract: The present invention relates to method for filling deformable karst cave, and the steps are: penetrating a grouting pipe into an elastic silicone tube, penetrating the grouting pipe and the elastic silicone tube into a deformable bracket, and lowering into a karst cave; sealing the elastic silicone tube, injecting silicate resin materials into the grouting pipe, and injecting steel fiber reinforced grout to implement a “block stone-like” structure; sealing the elastic silicone tube, separating the “block stone-like” structure from the elastic silicone tube to complete a “block stone-like” structure; lowering the elastic silicone tube and the deformable bracket, sealing the elastic silicone tube, lowering the elastic silicone tube and the deformable bracket tore construct the “block stone-like” structure, and completing the filling. The present invention may effectively stabilize the karst cave, ensure safe tunnel construction and stable surrounding rocks, and improve engineering construction speed.

Abstract: The present disclosure provides a determining device for the weathering resistant capability of clastic rocks in a tunnel based on feldspar features, which overcomes the shortcomings of current evaluation methods, is easy to operate, can be used to detect the type, content, and crystal structure of feldspar in a rock stratum, and integrates the information by combining a computer deep learning method to determine the weathering resistant capability of clastic rocks containing different types of feldspar in a tunnel, with high accuracy.

Abstract: The present invention belongs to the technical field of ocean traffic engineering, and relates to a fabricated ocean tunnel structure with an escape device and an application method thereof. The present invention includes a fabricated ocean tunnel structure and an escape device. the partition plate separates a middle bin in the tunnel, and the escape device is connected into the middle bin; and the escape device includes a rescue capsule, transverse ladders are evenly arranged in the rescue capsule, and a balancing weight block and a rescue equipment area are arranged at the bottom of the rescue capsule. The ocean tunnel structure can be provided with a rescue device during installation, and the safety of personnel escape can be guaranteed; therefore, the safety of the ocean tunnel structure is improved, cost is relatively low, secondary damage to the ocean tunnel structure is not needed.

Abstract: The present disclosure provides a grouting and water-plugging device for a fractured rock in a mine coupling state and a test method, and relates to the technical field of rock mechanics testing. The device includes a pressurizer, a reservoir, a test box, and a grouting pump. The reservoir includes a temperature sensor and a pressing-water plate. The pressing-water plate is connected to the pressurizer through a pressurizing rod. A pressure measuring pipe and a drainage pipe are installed on an outer side of the reservoir. The reservoir is connected to a water pump through a water injection pipe. The test box includes a rock, a transverse force exerting plate, a longitudinal force exerting plate, a stress sensor and the temperature sensor. The longitudinal force exerting plate is provided with multiple water through holes. A sliding box door is hinged to a front wall of the test box. The pressure measuring pipe and the drainage pipe are installed on a rear wall of the test box.

Abstract: A fractal power converter and a method for constructing the fractal power converter, the method for constructing the fractal converter including: replacing a switch and/or an energy storage element of an asymmetric half-bridge sub-module with the same asymmetric half-bridge sub-module for at least two times, replacing a switch and/or an energy storage element of a symmetric half-bridge sub-module with the same symmetric half-bridge sub-module for at least two times, and replacing a switch and/or an energy storage element of an H-bridge sub-module with the same H-bridge sub-module for at least two times. Compared with a conventional high-voltage and large-current power converter, the fractal power converter may output any high-voltage and large-current waveform. The system is modularized, the structure is simple and extensible, and voltage and current may be evenly distributed among the modules. The control method is simple and easy to standardize. Multi-port parallel output is allowed.

Abstract: A transcriptional regulator specifically responding to D-2-hydroxyglutarate (D-2-HG) and its application in the biological detection of D-2-HG. Wherein the transcriptional regulator is named DhdR and the nucleotide sequence is shown as SEQ ID NO: 1. The D-2-HG biosensors BD2HG-0 and BD2HG-1 are constructed using the transcriptional regulator DhdR and can detect biological samples containing D-2-HG.

Abstract: A screw pair including inner walls of screw holes in a working nut and a pre-tightening nut with sensor groups including a plurality of displacement sensors capable of measuring a value of a gap between an inner and outer wall of a screw in a diameter direction of the screw hole, the group includes four displacement sensors evenly distributed in a circumferential direction of the screw hole, every two displacement sensors are paired and symmetrical about a center axis, and projections of a plurality of sensor groups in an axial direction overlap the screw; and an adaptive excitation coil is mounted to each displacement sensor, which is capable of attracting the screw in a measurement direction of the adaptive displacement sensor, and a magnetic force of the coil attached is adjustable to change the value of the gap, so that axes of the screw, working nut, and pre-tightening nut coincide.

Abstract: A large-load unmanned aerial vehicle (UAV) for plant protection with adjustable spraying swath and pesticide application amount is provided, relating to the technical field of pesticide application of unmanned aerial vehicles. The large-load unmanned aerial vehicle for plant protection comprises a large-load unmanned aerial vehicle, a pesticide box, a variable pesticide application system, and adjustable spraying swath mechanisms, wherein the pesticide box is fixed to landing gears of the unmanned aerial vehicle and is positioned below a control platform of the unmanned aerial vehicle; the adjustable spraying swath mechanisms are arranged on the landing gears, the variable pesticide application system is connected with the pesticide box and the adjustable spraying swath mechanisms, the variable pesticide application system and the adjustable spraying swath mechanisms are electrically connected with the control platform, and the control platform is in communication connection with a remote control handle.

Abstract: Provided is a steam jet multifunctional aircraft deicing vehicle with steam jet, includes a vehicle body, where a steam generating assembly is arranged in the vehicle body, and the steam generating assembly is connected with a steam conveying assembly. A moving assembly is rotatably connected above the vehicle body, and the moving assembly is rotatably connected with an execution assembly. The execution assembly includes a first spray head assembly and a second spray head assembly. The steam conveying assembly includes a first supercharger and a second supercharger arranged side by side, where an air outlet end of the first supercharger is communicated with one end of a first air outlet pipe, and an other end of the first air outlet pipe is communicated with spray heads of the second spray head assembly through a first air pipeline.

Abstract: A model predictive virtual synchronous generator inverter control method considering a frequency-movement direction includes: obtaining a current frequency absolute value based on fundamental frequency of an inverter and a steady-state absolute value based on the fundamental frequency of the inverter; determining a frequency-movement state by comparing the above two absolute values: in a state of deviating from the fundamental frequency or a state of regressing to the fundamental frequency; setting a corresponding prediction output horizon according to the frequency-movement state, and constructing a cost function considering the frequency-movement state; and calculating an optimal virtual power increment value based on the cost function, then calculating an optimal virtual power, inputting the optimal virtual power to a swing equation of a virtual synchronous generator, and performing frequency adjustment according to an output value.

Abstract: A power flow calculation and AC/DC hybrid power flow calculation method for a flexible DC transmission system, the method including: according to the flexible DC transmission system under different control strategies, constructing a unified power flow model with a unified structure; determining a current main converter station, a current control strategy and an initial value and a limit value thereof, and forming the power balance equations under the current control strategy according to the unified power flow model; updating the current DC node voltage according to the voltage variation obtained by solving the power balance equations, and, if the updated DC node voltage exceeds the limit value, switching the control strategy; and if the updated DC node voltage does not exceed the limit value and the iteration constraints are not satisfied, alternating the main converter station according to the priority until iteration is completed.

Abstract: A wall-climbing robot system and method for rapid nondestructive inspection of hidden defects in culverts and sluices. The system includes: a robot vehicle body; navigation positioning system and moving system, both mounted on the robot vehicle body; automatic knock inspection system, mounted at the vehicle body front end; mobile ultrasonic rapid inspection system and corrosion inspection system, dual-power system, formed by a non-contact negative pressure adsorption apparatus and rotor booster apparatuses, the non-contact negative pressure adsorption apparatus mounted on the vehicle body bottom, the rotor booster apparatuses mounted on two sides of the vehicle body; and a master controller, communicating with the navigation positioning system, moving system, automatic knock inspection system, mobile ultrasonic rapid inspection system, corrosion inspection system, and dual-power system.

Abstract: An alumina-based ceramic tool material with low thermal expansion and a preparation process thereof, accordingly, the ceramic tool material may have both the high hardness of alumina ceramics after the hot pressing sintering, and reduces the thermal expansion coefficient of the overall ceramic material by adding the Sc2W3O12 as the negative thermal expansion phase, which improves the thermal shock resistance of ceramic tools in high-speed cutting engineering and meets the requirements of large temperature range during the machining of nickel-based superalloys. Moreover, the composite material does not use metal binder and has strong thermal stability even in the high-speed machining under extreme heat-force-chemistry coupling, so it has a high machining compatibility for nickel-based superalloys.