59results about How to "The method is simple and reliable" patented technology

The invention provides a split type shielding electric gear pump and a cooling method thereof, and can solve the problems that a motor and a gear pump of an existing integral type shielding electric gear pump cannot be independently assembled, the motor and the gear pump cannot be integrally decomposed, so that the gear pump is inconvenient to independently carry out a running-in test, and the gear pump leaks. The electric gear pump comprises a gear pump body and a motor, the gear pump body comprises a pump shell and a pump shaft, the motor comprises a machine shell, a stator and a rotor, one end of the pump shell is connected with one end of the machine shell through a sealing end face, air gaps are formed among the rotor, the stator and the machine shell, the input end of the pump shaft extends out of the pump shell and extends into the machine shell, and a leakage gap is formed between the input end of the pump shaft and the pump shell. The input end of the pump shaft is coaxially connected with one end of the rotor, the rotor is provided with an axially-through motor backflow channel, the pump shaft is provided with an axially-through gear pump backflow channel, and the space in the pump shell, the leakage gap, the air gap, the motor backflow channel and the gear pump backflow channel form a working medium cooling loop.

The invention discloses a non-intrusive permanent magnet synchronous servo motor bearing fault on-line diagnosis method and system, and the method comprises the steps: injecting a chirp current signal in a tuning stage, calculating a frequency response function through combining with a rotating speed feedback signal, and determining a resonant frequency according to the frequency response function; calculating a theoretical characteristic order according to the motor bearing size parameter; in a motor operation stage, collecting a motor rotating speed signal and determining a theoretical characteristic frequency according to the theoretical characteristic order; determining an optimal resonance demodulation frequency band according to the resonance frequency and the theoretical characteristic frequency, and performing band-pass filtering on the motor rotating speed signal according to the optimal resonance demodulation frequency band; an envelope signal of the filtered signal is calculated online through an orthogonal demodulation algorithm, the frequency spectrum of the envelope signal is obtained through FFT analysis, threshold comparison is conducted on the frequency spectrum of the envelope signal and the amplitude corresponding to the theoretical characteristic frequency, and fault diagnosis result judgment is completed. According to the invention, on-line diagnosis of the bearing fault of the permanent magnet synchronous servo motor under the condition of low-performance chip resources is realized.

The invention discloses a pretreatment method and application of an aluminum oxide loaded copper oxide-rare earth metal oxide catalyst. The pretreatment method comprises the following steps: adding an aluminum oxide loaded copper oxide-rare earth metal oxide catalyst for the reaction of preparing higher alcohol from ethanol into a mixed solution of one or more of C1-C8 alcohols, dipping at 10-90 DEG C for 1-24 hours, filtering to remove redundant alcohols after dipping is completed, and drying in a drying oven at 40-200 DEG C for 1-24 hours to complete the pretreatment of the catalyst. The invention provides the application of the aluminum oxide loaded copper oxide-rare earth metal oxide catalyst treated by the pretreatment method in the reaction of preparing higher alcohol from ethanol. According to the pretreatment method disclosed by the invention, the selectivity of the product higher alcohol is remarkably improved, and the conversion rate of the ethanol is unchanged or slightly improved, so that the problem that the conversion rate and the selectivity are difficult to consider at the same time in the prior art is solved.

The invention discloses a method for quantitatively analyzing preferred mineral components based on XRD (X-Ray Diffraction), and belongs to the field of mineral quantitative analysis. The method comprises the following steps: correcting different degrees of preferred orientations of different crystal faces through multiple factors of each crystal face, and substituting the corrected diffracted intensity into a reference intensity method calculation formula to obtain the mass fraction of each component in the mixed mineral. According to the method, the mass fraction of each component in the mixed mineral can be accurately calculated, and a more reliable method is provided for quantitative analysis of the mineral.

The invention discloses a method for preparing a low-loss sharp-bend waveguide through femtosecond laser in-situ multi-time modification, belongs to the technical field of laser processing, and adopts femtosecond laser in-situ multi-time modification to accurately optimize the problem of large bending loss of a 90 sharp-bend waveguide in single direct writing. The main principle is as follows: femtosecond laser is focused in a material by controlling a high-precision three-dimensional motion platform, and femtosecond laser processing energy and laser scanning speed are adjusted to reach preparation conditions of a single-mode waveguide; and performing in-situ multi-time modification regulation and control on waveguide performance by using femtosecond laser to prepare 90 low-loss sharp-bend waveguides with different bending radiuses. In-situ multiple modification enables the structure of the material modified by laser in the material to be more compact, the refractive index of the core layer of the waveguide is increased, and radiation loss can be inhibited; in-situ multi-time modification can also drive foreign ions in the waveguide to migrate to the waveguide boundary, scattering and absorption of light by the foreign ions are reduced, and absorption and scattering loss of the waveguide is reduced. The method is simple in preparation process, high in reliability and easy to implement.

The invention discloses a method for predicting the cycle life of a lithium iron phosphate battery. The method comprises the following steps: (1) testing the cycle performance of the lithium iron phosphate battery, establishing a relation curve of the cycle number and the capacity retention ratio, and solving a relational expression of the cycle number and the capacity retention ratio; (2) respectively carrying out cycle performance test on the lithium iron phosphate battery according to the set cycle number, carrying out empty electricity and full electricity treatment after the test is finished, and disassembling a positive pole piece and a negative pole piece; measuring the expansion rate of the negative pole piece, and establishing a relational expression between the capacity retention rate and the expansion rate of the negative pole piece; and 3) carrying out cycle performance test on the lithium iron phosphate battery to be predicted according to a set cycle number, then disassembling the lithium iron phosphate battery to be predicted, calculating the expansion rate of the negative pole piece, substituting the expansion rate into the relational expression in the step 2) for calculation to obtain a capacity retention ratio, and then substituting the capacity retention ratio into the relational expression in the step 1) for calculation to obtain the cycle life of the lithium iron phosphate battery to be predicted. The method can achieve the precise prediction of the service life of the lithium iron phosphate battery.

The invention belongs to the field of preparation analysis, and discloses a method for establishing an HPLC (High Performance Liquid Chromatography) fingerprint spectrum of detoxification and hematogenesis granules. According to the invention, a method of combining the HPLC fingerprint spectrum and the chemical mode of the detoxification and hematogenesis granules is established, the contents of the deacetylasperuloside, the rosmarinic acid, the scutellarin, the luteolin, the apigenin and the kaempferol in the detoxification and hematogenesis granules are detected at the same time, and a comprehensive quality evaluation model of the detoxification and hematogenesis granules with different batch numbers is established, so that the analysis result is comprehensive and objective; the method is simple, convenient, reliable, good in repeatability, accurate, stable and high in sensitivity, the multi-component content determination method provides scientific support for quality supervision of the Zhuang medicine preparation detoxification and hematopoiesis granules, and the method can be used for comprehensive quality evaluation and control of the detoxification and hematopoiesis granules. Therefore, the production stability of product quality and the safety and effectiveness of clinical medication are ensured.

The invention discloses a method for repairing creep damage of a nickel-based superalloy for a gas turbine blade, relates to the field of creep damage repairing, and is used for repairing a repaired part, the creep of the part to be repaired is before the end of a third creep stage, and the part to be repaired is the gas turbine blade made of the nickel-based superalloy Mar-M247. Comprising the following steps that S1, a to-be-repaired part is subjected to hot isostatic pressing treatment; s2, the to-be-repaired part subjected to hot isostatic pressing treatment is subjected to solution treatment; and S3, the to-be-repaired part subjected to solution treatment is sequentially subjected to high-temperature aging treatment and low-temperature aging treatment, and repairing of the creep damage of the to-be-repaired part is completed. Through hot isostatic pressing, solution treatment and two times of aging treatment, the damaged structure of the creep damaged alloy is recovered to a uniform cubic form, and the creep property is recovered to be close to or even beyond the original level.

The invention relates to the technical field of petroleum equipment and engineering machinery, and provides a system and method for automatically adjusting the inclination angle of a well drilling and workover two-layer operating platform, the system comprises a derrick and a two-layer operating platform rotationally connected with the derrick, and further comprises a rope winding system, and the rope winding system comprises a steel rope, a pulley block, a movable pulley and a second fixed pulley; the two ends of the steel rope are fixed to the top of the derrick and the top of the two-layer operation table respectively, and the steel rope sequentially winds around the second fixed pulley, the pulley block, the movable pulley and the pulley block from the fixing point of the top of the derrick and is finally fixed to the fixing point of the top of the two-layer operation table. A tensioning device is further arranged on one side of the derrick and fixedly connected with a transmission device through a first fixed pulley, and the other end of the transmission device is fixedly connected with a movable pulley. A tilt angle sensor is mounted on the second-layer operation table; the system further comprises a driller control system. The structure is compact, the method is simple and reliable, and an operator can operate in a driller room or a driller box centralized control position.

The utility model relates to the technical field of railway vehicle parking devices, and discloses a parking anti-running device position displaying device easy to identify and a parking device, the position displaying device comprises a reference assembly arranged on a main body, and the reference assembly is provided with a reference structure fixedly arranged relative to the main body; the travel switch assembly is arranged at one end of the middle of the main body, the reference structure is arranged on the travel switch assembly, and the position displaying assembly is arranged on the travel switch assembly and matched with the reference structure. The position displaying assembly can telescopically move along with the state change of the travel switch assembly, and when the position of the position displaying assembly moves, the position of the position displaying assembly can be changed relative to the position of a reference structure of the reference assembly, so that a field worker can directly observe the relative position state of the position displaying assembly and the reference structure at the moment, and the position displaying assembly can flexibly move along with the position displaying assembly. Therefore, the working state of the parking device can be quickly and effectively judged.

The application discloses a positive electrode material and a preparation method and application thereof, and the preparation method comprises the following steps: mixing iron phosphate, a carbon source, a sodium source and water to prepare a slurry; the mixed iron phosphate contains phosphate and pyrophosphate or phosphate and dihydrogen phosphate; the carbon source contains citric acid; the prepared slurry is grinded to obtain a fine slurry; the fine slurry is sprayed and dried to obtain a solid precursor; and the solid precursor is sintered to obtain the positive electrode material. By controlling the reaction parameters, the mixed iron phosphate containing pyrophosphate or dihydrogen phosphate is synthesized, the amount of citric acid in the subsequent process is reduced, the pore generation rate is reduced, the material compaction density is improved, the method is simple and reliable, and the application prospect is good. The prepared positive electrode material has high specific capacity and high compaction density, and is suitable for preparing a positive electrode of a sodium ion battery.

The invention relates to the technical field of biology, in particular to a quality control method for evaluating forensic case sample extraction and amplification. The invention provides a quality control product which can be used for forensic detection material extraction and amplification quality control, the quality control product is plasmids respectively containing EQCS small fragments and EQCL large fragments, the quality control product is applied to forensic detection material extraction and detection quality control, the method is simple and reliable, the compatibility with an existing detection kit is high, and the quality control product has wide application prospects.

The present invention discloses a method for selecting a grinding device for treating polymer injection discharge, which includes the following steps: data collection, investigating and understanding the commonly used tool types, the properties of discharge, and the commonly used discharge flow rate; simulation calculation, using simulation software and tool models to calculate the working conditions of the grinding tools under all working conditions and collect the results; verification and verification, according to actual production requirements and working conditions, determining the type and structure of the grinding tools, selecting multiple groups of grinding tools that can meet the grinding requirements, and conducting on-site tests to select grinding tools that meet the wear rate requirements. This is to solve the current problems of excessive wear and erosion of grinding tools in the discharge treatment process.

The utility model relates to the field of glove box door plates, in particular to an automobile glove box door plate structure which comprises a box sleeve, rotating shafts are rotationally connected to the front portion and the rear portion of the lower portion of the front face of an inner cavity of the box sleeve through bearings, torsion springs are fixedly connected to the surfaces of the rotating shafts in a sleeved mode, and arc-shaped grooves are formed in the front portion and the rear portion of the surface of the box sleeve. A limiting block is slidably connected to the inner side of the arc-shaped groove, an arc-shaped connecting rod is bolted to the right side of the limiting block, a box door is bolted to the inner side of the rotating shaft, and the front side and the rear side of the box door are both bolted to the other end of the arc-shaped connecting rod. Through the box sleeve, the rotating shaft, the torsion spring, the arc-shaped groove, the limiting block, the arc-shaped connecting rod and the like, articles in the automobile glove box can be conveniently taken and placed under the dark condition, the limiting block extrudes the induction pressing block by opening the box door, and the mode that a lighting lamp is connected with an automobile power supply access is convenient and reliable; and the illuminating lamp can be turned on and turned off in time.

The invention provides a photoetching liquid, a long-life photoetching electroluminescent device and a preparation method thereof, and the photoetching liquid comprises modified quantum dots, acrylic acid modified epoxy resin, a photoetching solvent and an initiator; the modified quantum dots comprise quantum dots and modified ligands modified on the surfaces of the quantum dots, and the modified ligands can be in reaction connection with the acrylic acid modified epoxy resin during polymerization reaction.

The invention provides a double-arm task planning method for a deep-canopy picking robot with self-adaptive fruit distribution characteristics, and the method comprises the steps: extracting a hand-eye combination region of interest, segmenting a left / right arm exclusive region and a double-arm connection region, carrying out the pre-distribution according to the minimum difference value of the number of fruits distributed by double arms, and calculating the picking execution time of the left arm and the right arm based on a pre-distribution result; in the process of calculating the picking execution time of the left / right arm, solving the shortest path of the left / right arm through a genetic algorithm, and taking the shortest path as the execution path length of sequential planning of the left and right arms; in the process of solving the shortest path of the left / right arm, introducing a strong constraint that a time difference value between a picking path sequence planning starting point and a corresponding dangerous fruit is greater than TM / N3; according to the picking execution time of the left arm and the right arm, the number of fruits of the left arm and the right arm is redistributed, and finally the shortest path for picking the redistributed fruits of the two arms is obtained. The problems that the utilization rate of a mechanical arm is low and the picking success rate is low in the fruit picking process with large distribution position difference of deep-canopy fruit trees are solved.

The present invention discloses a method and system for multi-robot anti-collision, belonging to the technical field of multi-robot cooperative control. For at least two robots, each robot is equipped with a set of wireless ad hoc network communication equipment; calculation is performed on the robot end to obtain the robot's own target speed, and the anti-collision speed is calculated according to the distance with other robots in the network, and the target speeds of other robots in the network are obtained and each adjustment coefficient is determined according to their distance; the robot's own target speed, the anti-collision speed, and the adjustment speed vectors of other robots are added to calculate the final target speed of the robot; each robot in the network calculates its own final target speed and runs according to its own final target speed. The present invention can realize fast and effective transmission of information between robots, the method is simple and reliable, and can adapt to various complex formations and any number of robots.

The invention relates to the field of conveyor belt joint detection equipment, in particular to steel wire rope core conveyor belt joint positioning and marking equipment which comprises a positioning and marking system control unit, a man-machine interaction unit and a frame body, the frame body comprises a bottom frame and an arch-shaped frame, one end of the bottom of the arch-shaped frame is rotationally connected with the bottom frame, and one end of the bottom frame is hinged to a first air cylinder; one end of the first air cylinder is hinged to one side of the arch-shaped frame, an electromagnetic detection unit is arranged on one side of the top of the arch-shaped frame, a paint spraying unit is arranged on the other side of the top of the arch-shaped frame, and a speed detection unit is arranged on a cross beam of the arch-shaped frame. The positioning marking system control unit judges the lap joint type and length of a steel wire rope core connector according to the magnetic flux leakage characteristic, the paint spraying unit sprays the detected lap joint type and length of the connector on a conveying belt in a pattern mode according to feedback of the positioning marking system control unit, and the position and the lap joint type of the connector are marked.

The invention discloses a dielectric film testing method based on ellipsometry and ultraviolet visible spectrum mutual calibration, which comprises the following steps: firstly, fitting an ellipsometry spectrum to obtain initial values of a refractive index and an extinction coefficient, comparing with a normal extinction coefficient dispersion model, and determining an abnormal wave band; secondly, fitting the transmitted spectrum, and intercepting the refractive index and extinction coefficient of the transmitted spectrum corresponding to the abnormal wave band of the ellipsometer; then calculating a weighting factor and a translation factor, and calibrating a refractive index and an extinction coefficient of a transmission spectrum in an abnormal wave band; and finally, correcting the ellipsometric spectrum of the abnormal wave band, and re-fitting to obtain the calibrated refractive index and extinction coefficient. According to the dielectric film testing method based on ellipsometry and ultraviolet visible spectrum mutual calibration, the result of the ultraviolet visible spectrum is applied to internally mark the ellipsometry spectrum of a specific wave band, accurate fitting of the refractive index and the thickness is achieved, and therefore the dielectric film detection precision is improved.

The invention relates to the technical field of conveying belt detection, in particular to a steel wire rope core conveying belt connector positioning and marking system and a positioning and marking method. The speed detection unit is used for detecting the running speed of the conveying belt; the electromagnetic detection array is used for detecting the magnetic flux leakage amount of the conveying belt; the paint spraying system is used for spraying paint on the conveying belt according to the joint lap joint type and length of the conveying belt; and the system control unit receives the running speed and the magnetic flux leakage amount of the conveying belt, obtains the position and the type of the joint according to the magnetic flux leakage amount, and then controls the paint spraying system to run according to the running speed of the conveying belt and the position and the type of the joint. Meanwhile, the invention further discloses a positioning and marking method of the positioning and marking system. Based on the size of the leakage magnetic field, the lap joint type and the joint length of the steel wire rope core conveying belt joint are judged according to the relation between the lap joint mode of the conveying belt joint and the leakage magnetic field, the method is simple and reliable, and the recognition rate is high.

The invention discloses an antenna array signal receiving time delay estimation method applied to deep space exploration, and the method comprises the steps: all antennas in an antenna array and a far-end reference antenna receive signals transmitted by the same deep space target at the same time, and obtaining the equipment time delay of each antenna in the antenna array according to the position information of the deep space target and each antenna; according to the device time delay of each antenna in the antenna array, obtaining the time delay of each antenna receiving a signal in the antenna array; the time delay comprises space time delay and equipment time delay; the space time delay is the time delay of the deep space target arriving at the antenna; the equipment time delay is the time delay of the signal from the antenna to the array signal synthesis equipment. The method provided by the invention is simple and reliable, is convenient to implement, and can meet the calibration requirement of the relative delay inequality of each antenna participating in the arraying without adding any external equipment.

The invention is suitable for the technical field of automobile aerodynamics, and provides a self-adaptive flexible spoiler experimental development method under a yaw working condition, and the method comprises the steps: arranging and driving a flexible spoiler in a wind tunnel; the parameters of the spoiler are optimized with the wind resistance coefficient as the target at the multiple yaw angles; designing a piecewise linear rule controller based on an optimization result; pressure monitoring points are arranged on the two sides of a vehicle body, the regression relation between the pressure difference and the yaw angle is established, and the yaw angle is recognized in real time; developing a self-adaptive resistance reduction optimization program, driving the spoiler to be adjusted to the optimal form in real time according to the identified yaw angle, and verifying the resistance reduction effect of the spoiler; a mathematical method is used for calculating the curved surface shape of the spoiler, and reference is provided for automobile appearance design. Aerodynamic configuration self-adaptive adjustment of the vehicle under the crosswind working condition can be achieved, the wind resistance optimization capacity of the real vehicle in the running process is remarkably improved, and an effective experimental method and design basis are provided for low-wind-resistance development of the vehicle.

The invention discloses an optimal control method for improving the power tracking precision of a hybrid synchronous converter, and belongs to the field of power electronic technology and power system control. The invention provides an improved control strategy based on a series high-pass filter in order to solve the problem of low active power tracking precision caused by steady-state coupling of a voltage synchronization loop in existing hybrid synchronization control. According to the invention, the high-pass filter is connected in series in the voltage synchronization loop, continuous interference of a steady-state power angle to the frequency is blocked by utilizing the direct current blocking and alternating current alternating current characteristics of the high-pass filter, and the power synchronization loop independently dominates the steady-state frequency, so that the steady-state power error is thoroughly eliminated, and zero-static-error tracking is realized. And meanwhile, the response capability of the voltage synchronization loop to transient high-frequency disturbance is reserved, so that the excellent transient damping characteristic of the hybrid synchronization control strategy still exists. In addition, the method is simple in structure, does not need to depend on complex system parameter identification, and has high robustness and engineering adaptability.

The invention provides a printer motor variable speed control method, a printing device, a medium and a program product, and the method comprises the steps: obtaining a first motor speed adjustment parameter group of to-be-printed data of a preset line number; smoothing the first motor speed adjustment parameter group to obtain a second motor speed adjustment parameter group, and storing the second motor speed adjustment parameter group in a cache region; printing is carried out based on the cache region, and in the printing process, the steps that third motor speed adjusting parameters of a new printing line are obtained, and the new printing line and the current printing line are separated by a preset line number; and comparing the third motor speed adjusting parameter of the new printing line with a fourth motor speed adjusting parameter of the previous printing line of the new printing line to determine an adjusting area starting from the previous printing line of the new printing line in the cache area, smoothing the adjusting area, and updating the cache area according to the updated third motor speed adjusting parameter. Good motor variable speed control is achieved, and the implementation mode is simple.

The present invention relates to a chlorinated paraffin tail gas purification device, comprising an oil removal unit, a water removal unit and a chlorination unit connected in sequence; the oil removal unit is used to cool and recover wax oil and chlorinated products thereof in the chlorinated paraffin tail gas; the water removal unit is used to absorb water in the chlorinated paraffin tail gas; the chlorination unit comprises a chlorination reactor (8), which selectively absorbs chlorine in the tail gas through a ferrous chloride solid absorbent. The present invention also relates to a chlorinated paraffin tail gas purification process using the chlorinated paraffin tail gas purification device and an application of the chlorinated paraffin tail gas purification device. Compared with the prior art, the present invention has the advantages that the chlorinated paraffin tail gas purification device can simultaneously reduce the oil content, water content and chlorine content in the chlorinated paraffin tail gas, and has high efficiency and low energy consumption.

This invention relates to a method for refining and classifying coking coal based on petrographic and matrix strength, comprising: determining the petrographic composition of the coking coal; placing the prepared sample in a dry distillation reactor for dry distillation reaction; pulverizing; taking a sample with a weight of M0 and placing it in a type I rotary drum for a rotational experiment, then sieving and recording the weight of coke particles larger than 0.2 mm as M1; calculating the matrix strength I. cb = (M1 / M0)*100%; based on the vitrinite content V and matrix strength I in the coal and petrographic composition. cb This invention enables the detailed classification of coking coal. It can quickly distinguish between coking coal types with similar conventional coal quality indicators and further classify them, providing a reliable basis for coking coal quality evaluation and blending guidance. The method is simple, reliable, low-cost, and timely, making it suitable for coal and coking enterprises and possessing broad application value.

The invention provides a molten steel refining method adopting an RH vacuum refining system, and the RH refining process comprises the following steps: pretreatment: after a steel ladle enters an RH refining station, inserting an RH dip pipe below the liquid level of molten steel; vacuum refining is conducted, specifically, vacuumizing is conducted, argon is blown into an ascending pipe of the RH dip pipe, when the pressure in a vacuum chamber reaches 20-200 Pa, the ascending pipe of the RH dip pipe is adjusted to lift the gas flow, and when the pressure in the vacuum chamber reaches the ultimate vacuum and the gas flow can be stably lifted, vacuum refining is completed; the inclined angle between each argon blowing hole and the horizontal plane is 30 degrees; alloying is conducted, specifically, the molten steel is alloyed in the RH vacuum refining treatment process; after alloying is completed, the components of the molten steel are detected, and if soft blowing treatment needs to be conducted on the molten steel, soft blowing is conducted on the molten steel; and if soft blowing is not needed, the RH refining of the molten steel is completed. The inclination angle of the argon blowing gas hole is changed, the lifting force of the blown gas to the molten steel is increased, then the circulating flow of the molten steel in the RH is increased, the cleanliness of the molten steel is improved, and therefore the steel product quality is improved.

The utility model discloses a plate drying device capable of controlling the plate placing distance, and relates to the field of plate processing. The utility model discloses. The device comprises a mounting frame, a baking module and a displacement module, and the displacement module is arranged in the middle of the mounting frame; the baking module is arranged at the upper end of the mounting frame; the displacement module and the baking module are in intermittent fit. According to the device, the position of a plate can be conveniently, rapidly and manually adjusted, no electric control sensing equipment participates in, the working effect is more stable, the problem that an existing plate surface drying mode lacks convenient, stable and reliable plate position moving is solved, and troubles are added to workers.

This invention provides an automated monitoring method for vegetation change in open-pit mining areas based on long-term time-series remote sensing data, belonging to the field of remote sensing and geographic information technology. The method includes the following steps: S1. Data acquisition and preprocessing: Acquire all data from the mining area during the study period, and obtain NDVI time-series data through cropping, NDVI calculation, maximum value synthesis, and filtering; S2. Template creation: Based on statistical analysis of the filtered NDVI time-series data, obtain the NDVI values ​​of vegetation and bare soil in the mining area, and generate NDVI templates for different vegetation change trajectory types by combining typical vegetation change patterns in open-pit mining areas; S3. Vegetation change trajectory type classification: Using the NDVI templates as training data, obtain the vegetation change trajectory type for each pixel in the mining area using a DTW-based KNN classification method; This invention can achieve a highly automated monitoring method for vegetation change in open-pit mining areas without sample training or parameter setting.

The invention relates to a power distribution network fault line selection method and system. The method comprises the steps of judging whether a zero sequence voltage value of a neutral point exceeds a preset proportion of a phase voltage value or not according to a preset power distribution network operation regulation; if so, determining that a grounding fault occurs, and triggering a line selection program to record the transient zero-sequence current of each line; decomposing the transient zero sequence current by using variational mode decomposition (VMD) to obtain an intrinsic mode function (IMF) component corresponding to each line; a plurality of IMF components are provided; performing fast Fourier transform (FFT) analysis on the IMF component to obtain a power frequency component in each transient zero-sequence current, and removing the power frequency component to obtain a non-power frequency component of each line; after the non-power-frequency components are smoothed, a correlation coefficient matrix of each line is obtained through calculation; and inputting the correlation coefficient matrix into a K-means clustering algorithm, and obtaining a fault line according to an output clustering result. And the accuracy and efficiency of ground fault line selection are improved.