Abstract: Provided is a solvent extraction method for a petroleum sludge/oil sand assisted by a particle dispersant, including: mixing a solution dissolved with the particle dispersant and the petroleum sludge/oil sand to obtain a mixture, and subjecting the mixture to solvent extraction and separation to obtain a solid phase particle and an oil-carrying liquid phase; wherein the particle dispersant includes one compound selected from the group consisting of a polyoxyethylene alkyl ether carboxylic acid, a polyoxypropylene polyoxyethylene alkyl ether carboxylic acid, and dodecylbenzene sulfonic acid; and a solvent used in the solution dissolved with the particle dispersant comprises one or more selected from the group consisting of cycloalkane and toluene.

Abstract: Disclosed is a biped robot and multi-configuration robot capable of being spliced autonomously, and a control method of the multi-configuration robot. The biped robot comprises a torso, arms, legs, a tolerance docking sleeve, and a torso docking device. The arms are correspondingly arranged at the left and right sides of the torso, and two legs are arranged at the lower side of the torso. The tolerance docking sleeve is movably arranged at the rear side of the torso through a base, and the torso docking device is fixed to the front side of the torso. Single biped robots in the present disclosure can form a multi-configuration legged combined body in a self-organization and reconstruction mode so as to achieve bipedal, quadrupedal, hexapodal and other multi-legged configurations. The motion stability and the load capacity of the legged robot are improved through the splicing combination of the modular legged robots.

Abstract: Provided are a green sealing material for karst flowing water, and a preparation method and use thereof. The green sealing material includes a component A and a component B, with a volume ratio of the component A to the component B being in a range of 4:1 to 5:1; where the component A includes in parts by weight: 40 parts to 50 parts of a sulphoaluminate cement, 10 parts to 15 parts of a light-burned magnesium oxide, 1 part to 4 parts of boric acid, and 40 parts to 50 parts of water; and the component B includes in parts by weight: 0.2 parts to 0.4 parts of hydroxypropyl methylcellulose, 0.1 parts to 0.5 parts of polyacrylamide, 15 parts to 30 parts of potassium dihydrogen phosphate, 0.2 parts to 0.4 parts of triethanolamine, 0.5 parts to 1 part of lithium carbonate, and 80 parts to 100 parts of water.

Abstract: The provided is flux-weakening control method and system for the salient pole offset permanent magnet synchronous motor. The method includes determining the given value of electromagnetic torque according to the actual speed and the given target speed; calculating the current trajectories of MTPA and MTPV in dq coordinate system; obtaining the d?q? coordinate system by rotating the coordinate system, and calculating the current trajectory of MTPA and MTPV in the d?q? coordinate system to obtain the characteristic current; judging whether it is necessary to turn on the flux-weakening control, and outputting the direct axis current compensation when it turns on; judging the flux-weakening area of the motor; and generating the space vector pulse width modulation signal to drive the motor to realize the full speed range flux-weakening speed regulation of the salient pole offset permanent magnet synchronous motor.

Abstract: The present disclosure pertains to the field of power electronics technologies, and provides a grid-connected control method and system for a grid-forming converter without a grid-side voltage sensor. The grid-connected control method includes: performing coordinate transformation on a phase of a three-phase capacitor voltage sampled by a phase-locked loop (PLL) to obtain a first phase; in response to control of a first pulse width modulation (PWM) pulse signal, introducing a reference phase, and performing negative feedback regulation on a difference between the reference phase and the first phase to obtain a second phase; and in response to control of a second PWM pulse signal, performing a modulo operation on a difference between the reference phase and the second phase to obtain a third phase, where the third phase is used to replace a phase of the PLL to perform coordinate transformation of a system.

Abstract: A photothermal seawater desalination material with a multi-stage structure and a preparation method and application thereof. The photothermal seawater desalination material includes a light-absorbing material having a C/WO3-x heterogeneous junction, which is obtained by depositing a nano-C material on a porous metal foam material using plasma enhanced chemical vapor deposition (PECVD), and then synthesizing WO3-x with plasma resonance effect by a solvothermal reaction.

Abstract: The present disclosure relates to an efficient biodegradable dust suppressant for an open-pit mine and a preparation method therefor. The dust suppressant includes the following components in percentage by weight: 2%-3.5% of gallic acid, 1.5%-2% of sodium alginate, 0.25%-2% of a surfactant, 0.5%-1% of an antifreeze liquid, and balance water. The preparation method includes the following steps: (1) preparing the gallic acid; (2) preparing the antifreeze liquid; (3) weighing the components in parts by weight; (4) mixing the gallic acid, water, sodium alginate and antifreeze liquid; (5) adding the surfactant; and (6) adding the balance water to prepare the efficient biodegradable dust suppressant for an open-pit mine. The present disclosure has the characteristics of low temperature resistance, high temperature resistance, bonding, wetting, coal dust consolidation and the like, is biodegradable, and does not cause secondary pollution.

Abstract: Provided are an unequal-channel angular self-bending extrusion die and a method for designing and manufacturing the same and extrusion method thereof and includes following steps: designing a symmetrical streamlined extrusion die based on sine function; making the medial axis of the die cavity of the symmetrical streamlined extrusion die twisted and deformed on a certain plane; establishing the die cavity wall surface equation of the unequal-channel angular self-bending extrusion die; setting a working belt structure downstream the die cavity of the unequal-channel angular self-bending extrusion die.

Abstract: A multifunctional teaching demonstration device for economic management is provided. It includes a folding device the back of the folding device is provided with multiple folding components, the front of the folding device is provided with a display, the front of the display is flexibly connected to a transparent board, the left side of the display is flexibly connected to the first demonstration module, the right side of the display is flexibly connected to the second demonstration module, there are two first teaching aid cabinets under the first demonstration module and the second demonstration module, the bottom of the first teaching aid cabinets is flexibly connected to the second teaching aid cabinet.

Abstract: A high-impedance fault positioning method and system based on synchronous Lissajous curve characteristics are provided. The method includes: acquiring a bus zero-sequence differential voltage and a feeder zero-sequence current of a faulty line; constructing a first Lissajous curve in a characteristic frequency band range based on the bus zero-sequence differential voltage and the feeder zero-sequence current; when the proportion of the faulty line is less than a set threshold value and the slope of the first Lissajous curve is negative, determining that high-impedance faults have occurred in the faulty line; constructing a second Lissajous curve based on the bus zero-sequence differential voltage and the section zero-sequence current, performing linear fitting on discrete data points of the second Lissajous curve to obtain a fitted curve; and when the slope of the fitted curve is negative for at least three consecutive periods, determining that high-impedance faults have occurred in the section.

Abstract: A sand column grouting filtration experimental device includes a sand column, a grout injection structure connected above the sand column and a grout exit structure connected below the sand column, the sand column comprises a plurality of connecting units; Four screws are provided around the sand column, and the four screws run through the grout injection structure and grout exit structure; A bottom plate is provided below the grout exit structure, a support plate one and a support plate two are provided between the bottom plate and the grout exit structure, and a sand column consolidation structure is provided between the support plate two and the support plate one. The experiment adopts a segmented combined sand column, in addition to ensuring the experimental results that can be obtained by the general sand column, segmented study of the interception and percolation effect of cement slurry in the sand column is implemented.

Abstract: A stress-based comprehensive method and system for evaluating state of health of a power battery, medium and device, the method including: acquiring the stress and capacity of a battery charging and discharging cycle; correlating between acquired stress and capacity, calculating the battery charge and health states based on stress; evaluating the battery charge state by correlating the stress and battery charge state; acquiring a current battery capacity and internal resistance and predicting remaining useful battery life to calculate current capacity-based and internal resistance-based states of battery health respectively; and calculating a weighted sum of the battery state of health based on stress, the capacity-based and the internal resistance-based states of battery health, and obtaining a comprehensively evaluated state of battery health by combining the weighted sum and evaluated state of battery charge.

Abstract: The present disclosure pertains to the field of power electronics technologies, and provides a grid-connected control method and system for a grid-forming converter without a grid-side voltage sensor. The grid-connected control method includes: performing coordinate transformation on a phase of a three-phase capacitor voltage sampled by a phase-locked loop (PLL) to obtain a first phase; in response to control of a first pulse width modulation (PWM) pulse signal, introducing a reference phase, and performing negative feedback regulation on a difference between the reference phase and the first phase to obtain a second phase; and in response to control of a second PWM pulse signal, performing a modulo operation on a difference between the reference phase and the second phase to obtain a third phase, where the third phase is used to replace a phase of the PLL to perform coordinate transformation of a system.

Abstract: A non-destructive testing method for article moisture content based on radio frequency identification (RFID) includes: S1, an electronic tag is attached to a surface of an article to be tested, and a signal transceiver is arranged above the electronic tag; S2, the signal transceiver sends a radio-frequency signal to the electronic tag and activates the electronic tag, and the signal transceiver simultaneously receives a backscattered signal from the electronic tag; and S3, the signal transceiver sends the backscattered signal to a signal processor. The method utilizes effects of different moisture content on backscattered signals, arranges the electronic tag on the article to be tested, processes the backscattered signal through the signal processor to obtain a processed signal, and transmits the processed signal to a monitor to display real-time moisture content curve of each article to be tested based on its corresponding serial number.

Abstract: The present invention relates to the technical field of mine fire prevention and extinguishing, in particular to a liquid nitrogen direct injection and low-temperature foaming intelligent filling system based on mine fire area characteristics and an application method, comprising a liquid nitrogen storage tank, a liquid nitrogen direct injection system and a low-temperature foaming system, wherein the liquid nitrogen storage tank communicates with a liquid nitrogen pressurizing device through a main pipeline; a temperature control unit is arranged on the main pipeline; and the liquid nitrogen pressurizing device is connected with the liquid nitrogen direct injection system and the low-temperature foaming system, respectively, liquid nitrogen is directly injected into a foam liquid, to prepare a low-temperature foam type fire preventing and extinguishing material by means of forced convection, membrane boiling, explosion boiling and nucleate boiling between the liquid nitrogen and water.

Abstract: A ferromagnetic free layer, a preparation method and an application thereof are provided, where the ferromagnetic layer includes a magnetic film alloy, and the magnetic film alloy includes multiple layers of laminated films. A thickness of each of the films decreases gradually from a first end to a second end of the magnetic film alloy, so as to break in-plane structural symmetry of the magnetic film alloy, and the films include heavy metal films and ferromagnetic metal films, where out-of-plane crystal symmetry of the magnetic film alloy is broken by means of component gradients. When a current is applied in plane of the magnetic film alloy, a spin orbit torque will be generated, which directly drives the magnetic moment of the magnetic film alloy to undergo a deterministic magnetization reversal.

Abstract: A magnetic field-assisted vibratory finishing device for a minute structure and a finishing method is provided. The device includes a rotating shaft, a workpiece clamping device, a magnetic field generating device, a vibration assisting device, a three-axis precision displacement platform and a base. The magnetic field generating device includes a baffle plate, magnetic bars and a magnetic-pole groove. The vibration assisting device includes a housing, guide fixing rods, a vibration motor, a vibration connecting plate, and compression springs. The workpiece clamping device clamps parts with a variety of structural shapes, and a frequency controller can control the motion mode of the magnetic field generating device during the finishing processing, thereby controlling the motion track of grinding material.

Abstract: A method for realizing balanced displacement of crude oil by injection and production optimization coordinated chemical flooding which comprises the following steps: determining the median size and elastic modulus of viscoelastic particles according to the average permeability of the reservoir; optimizing the concentration ratio of the total concentration of the chemical agent; the physical parameters of each layer are counted, and the hierarchical system is combined according to the entropy weight algorithm and the cluster analysis method based on the gravity center method; the optimal section slug volume ratio of the single well injected with two slugs under the heterogeneity of the permeability of the strata is calculated; and the objective function is established by combining the coefficient of variation of remaining oil saturation, the effect of chemical flooding and the cost, and the numerical simulator is used to optimize the objective function.

Abstract: An ultra-rapid and highly-sensitive chemiluminescence immunoassay for the detection of thyroid stimulating hormone uses water-soluble CdTe QDs as a chemiluminescence reagent and PBS solution of KMnO4 with specific concentration and pH as an activator to construct a CdTe QDs/KMnO4 chemiluminescence system of nanoparticle luminescence; based on the semi-automatic test method, the ultra-fast and highly sensitive detection of TSH can reach the level of single molecule detection.

Abstract: The disclosed apparatus, systems and methods relate to a framelet-based iterative algorithm for polychromatic CT which can reconstruct two components using a single scan. The algorithm can have various steps including a scaled-gradient descent step of constant or variant step sizes; a non-negativity step; a soft thresholding step; and a color reconstruction step.