41results about How to "Overcome method" patented technology

The invention relates to a laser-displacement-sensor-based journal axle center measurement apparatus, and measurement and calibration methods thereof. The measurement apparatus comprises a measurement rack and two laser displacement sensors; and the two laser displacement sensors are installed on two intersected planes of the measurement rack respectively. The measurement rack is arranged nearby a journal of an axis component, so that a plane formed by intersection of two laser radiation lines is perpendicular to the axial central line of the journal. On the basis of the structure, the laser radiation lines of the two laser displacement sensors are fixed relative to the angel of the measurement rack; coordinates, relative to the measurement rack, of two light spot points of the laser radiation lines on the journal surface are obtained according to measurement values of the laser displacement sensors; on the premise that the diameter of the journal is known and the circular degree deviation can be ignored, position information of the axle center of the journal relative to the measurement rack is calculated based on the coordinates of the two light spot points; and a coordinate system is calculated by using a pin gauge. Therefore, problems existing in the existing image, contact type measurement head and pneumatic gauging methods can be solved; and industrial on-line measurement and application are realized conveniently.

The invention provides a vehicle fuel cell system and method for low temperature starting through an alloy hydrogen storage material. The vehicle fuel cell system comprises a fuel cell stack, an air path subsystem, a hydrogen path subsystem, a cooling liquid path subsystem and a control circuit subsystem, the hydrogen path subsystem comprises an alloy hydrogen storage tank branch path and a high pressure gas bottle branch path, and an alloy hydrogen storage tank is arranged in a water box of the cooling liquid path subsystem. The method for low temperature starting comprises the steps of making a high pressure gas bottle inflate an alloy hydrogen storage tank with hydrogen, when the hydrogen storage material is inflated with hydrogen, conducting heat release, heating cooling liquid in thewater box, when the cooling liquid reaches set temperature, starting a circulation water pump, heating a fuel cell electric stack, when the electric stack reaches set operable temperature, stopping hydrogen inflation and starting the fuel cell system. The vehicle fuel cell system and method have the advantages that fuel is not consumed, and external heating equipment is not added, so that high pressure gas bottle hydrogen storage and hydrogen storage material hydrogen storage supplement each other; when low temperature starting is not needed, the driving mileage of a fuel cell vehicle can alsobe increased.

The invention relates to a technique information expressing method based on a three-dimensional model, which is characterized by comprising three following steps: constructing technique information identification symbols, dynamically generating technique information combination symbols, and carrying out three-dimensional technique information labeling. The technique information expressing method can realize the interlinking of technique information and three-dimensional technique information by the three-dimensional labeling, and unify the design and the technique on a three-dimensional platform so as to replace a two-dimensional paper technique card, thereby solving the problems that the two-dimensional technique information is non-intuitionistic in expression, various in forms, hard in management and the like in the prior art.

The invention provides a device for detecting a zero crossing point of inductive current, aiming at the technical problem that the direction of inductive current can not be accurately judged by independently adopting a digital signal processor (DSP) hardware capture module (CAP) and a hysteresis comparison method. The device comprises a current sensor, a partial pressure conditioning module, a voltage following module, a pull-up bias module, a DSP module, an input module and a liquid crystal display (LCD) module. According to the invention, the phase locking function of a single-phase phase-locked loop based on a second-order generalized integrator (SOGI) is adopted, so that the phase locking for the inductive current can be realized, and the zero crossing point and the direction of the inductive current can be further detected. Through the device, the defects that separately using a hardware or software method is adopted are overcome; and equipment is simple, detection is convenient and fast and reliability is high.

The invention discloses a method for continuously detecting physical parameters of compact rocks. The method includes the steps: selecting a rock sample, drying the rock sample, measuring the size andweight of the rock sample, taking formation water, soaking a fiber with a gap, repeatedly rolling a rock core on the fiber, uniformly soaking the outer surface of the rock core except for two end surfaces, placing the rock sample into an adjusted nuclear magnetic resonance spectrometer to obtain a T2 spectral curve of the sample, taking out the rock sample to dry the rock sample, performing saturation treatment on the rock core by the formation water, and testing a T2 spectral curve by the nuclear magnetic resonance spectrometer; taking out the rock sample, placing the taken rock sample intoa rock core clamping device, applying displacement pressure until the displacement pressure reach a suitable displacement pressure difference value, accurately recording needed parameters after a system is stabilized, continuing to measure the rock sample by a soap film flow meter, measuring a T2 spectral curve of the rock sample again, and analyzing and calculating acquired data to obtain variousof needed parameters. The method has the advantages that data are accurate and reliable, time is saved, and the method is convenient and rapid.

The invention provides a calibration technology for a vision sub-pixel of an embedded type machine with optical path adjustment, which is a calibration technology of an adjustable optical path with on-line vision measurement. Main technologies including an optical path adjusting technology, a sub-pixel angular point extraction technology and a sub-pixel vision calibration technology are adopted in a calibration process, wherein the optical path adjusting technology comprises an optical intensity saturation prevention technology and an objective surface parallel-adjustment technology; the sub-pixel angular point extraction technology utilizes a spatial moment; and the sub-pixel vision calibration technology is based on an ideal grid. The invention overcomes the defects of the traditional measurement technology, carries out high-precision and high-stability calibration on a camera on a production line and can automatically carry out the vision measurement by using the calibration technology on the production line and finally detect the quality qualification of products; in addition, by adopting a design algorithm based on engineering idea, the invention has the advantages of high precision and speed, low requirements for production environment quality and high instantaneity, can well meet the requirements of industrial production, and has important significance on the vision measurement of the products in actual industrial production.

The invention is applicable to fields of water resource science, agriculture science and ecology, and provides a system and an apparatus for determining moisture content of a plant. The system comprises an electronic balance component, a heating component, a cooling component, an operation control component and a power supply, wherein the electronic balance component measures the fresh weight and the dry weight of a plant body; the heating component heats and dewaters the plant body; the cooling component cools the heated and dewatered plant body; the operation control component controls the working states of the electronic balance component, the heating component and the cooling component, and calculates and outputs the moisture content determination result of the plant body; the power supply supplies electricity to the electronic balance component, the heating component, the cooling component and the operation control component. By adopting the system and the apparatus, the functions of a microwave drying technology and an electronic balance are effectively coupled, the defects that the traditional apparatus is heavy and cannot quickly measure in real time, and the measurement by the traditional indoor method is low are overcome, the system and the apparatus are convenient to carry, quick to measure, and high in accuracy, and fast and accurate determination of the moisture content of each organ of a living plant on the scene can be achieved.

The invention relates to a monitoring device and a monitoring and judging method for cavitation of a venturi fertilizer injector. The monitoring device for the cavitation of the venturi fertilizer injector is characterized by comprising a dynamic strain indicator, a monitor, a strain gauge and a pressure sensor; the strain gauge is attached on the outer surface of the venturi fertilizer injector, the strain gauge is connected with the dynamic strain indicator, the dynamic strain indicator is connected with the monitor, the monitor is further connected with the pressure sensor, and the pressure sensor is arranged at an input-output port of the venturi fertilizer injector; an input module, a storage module, a data processing module, an alarm module and a display module are pre-arranged in the monitor; the input end of the input module is connected with the output ends of the dynamic strain indicator and the pressure sensor, the output end of the input module is connected with the input end of the storage module, the output end of the storage module is connected with the input end of the data processing module, the output end of the data processing module is connected with the alarm module and the display module, and the output end of the alarm module is connected with the display module. The monitoring device and the monitoring and judging method for the cavitation of the venturi fertilizer injector has low requirements on the external environment, and is small in device size, high in sensitivity, low in experimental cost, convenient and rapid to operate, and applicable to monitoring and judging the cavitation in fluid mechanical equipment.

The invention discloses a composite insulator ageing photo-thermal radiation detection system based on an unmanned aerial vehicle. The system comprises an airborne terminal 9 and a ground terminal 14,the airborne terminal comprises an unmanned aerial vehicle body 1, a power module 2, a flight control module 3, a satellite positioning module 4, a cloud deck 5, a photo-thermal radiation detection module 6, an airborne wireless transmission module 7 and an airborne information processing center 8, and the ground terminal comprises a ground wireless transmission module 10, a ground unmanned aerial vehicle control module 11, an image processing and displaying module 12 and a ground information positioning center 13. According to the system, the unmanned aerial vehicle carries the photo-thermalradiation detection module to detect temperature distribution time change or space distribution conditions of a composite insulator after laser radiation, the relationships among thermal conduction characteristics and aging degree of the composite insulator are analyzed, and photo-thermal radiation online remote sensing evaluation of an ageing state of the overhead composite insulator is achieved. The system has the advantages that the method and operation are simple, non-contact, lossless, high-sensitivity, efficient, online remote sensing evaluation of the ageing degree is achieved and thelike.

The invention relates to a cement concrete scale cleaning agent and a preparation method thereof. The cement concrete scale cleaning agent is prepared from the following raw materials in percentage by mass: 2-30% of organic acid, 1-5% of builder, 0.5-5% of penetrant, 0.1-2% of tackifier and the balance of tap water. The preparation method comprises the steps: preparing production equipment; accurately weighting the raw materials; adding half of the tap water, sequentially adding the organic acid, the builder, the penetrant and the tackifier while stirring at the rotating speed of 600-700rpm, and after all the raw materials are added, stirring at the rotating speed of 1000-1500rpm until the raw materials are completely dissolved; adding the residual tap water, and then, uniformly mixing at the rotating speed of 600-700rpm to obtain a cleaning agent product. According to the invention, the cleaning agent cannot corrode the equipment and can be used for clearing hardened cement concrete scales on the surface of the equipment without knocking, not only is the equipment protected, but also the water obtained after cleaning can be treated to be reused, so that the cleaning agent is pollution-free, safe and environment-friendly.

The invention discloses a drip-irrigating and film-mulching planting method, belonging to the planting method of farm crops. The drip-irrigating and film-mulching planting method comprises the following steps: a seed material is filled into a hopper of a seeder; a drip tube is coiled on a wheel disc and pulled to be below a pressing roller, a film-mulching roller and a film-pressing roller; a power output shaft is connected with rotation driving equipment; the seeder is pulled to walk, and machine wheels are used for driving a transmission shaft through chains and driving seeding wheels by using driving wheels and the chains; the drip tube wheel disc, the pressing roller, the film-mulching roller and the film-pressing roller are pulled by the walking of the seeder to rotate synchronously, and the working steps of paving the drip tube, pressing soil and mulching the film are carried out synchronously; and the power output shaft is used for driving a relieving soil-rotating rake to raise surface soil by using a gear box and the chain. The drip-irrigating and film-mulching planting method disclosed by the invention overcomes the defects of the traditional seedling method and irrigation method, can automatically finish multiple operations such as soil-turning, seeding, earth-covering, film-mulching, pressing, earth-covering on the film and irrigation below the film and can be pulled by using a fractional-horsepower four-wheeled locomotive, so that farmers are emancipated from heavy film-covering and planting work and the mechanization of film-mulching and planting is realized; because of the paving of drip irrigation, the waste and loss of water resources are reduced and the water resources are saved effectively; and the drip-irrigating and film-mulching planting method is simple in structure and convenient in operation.

The invention relates to sample preparation and detection of oil fatty acids and main accompanied components, and in particular, for the problems that when plant oil fatty acids and oil accompanied components of sterols, squalene, vitamin E and the like have different treatment methods during determination, gas chromatography detection can be performed after the fatty acids and the accompanied components need to be treated separately and the requiring time is longer, according to the properties of the fatty acids and the oil accompanied components of sterols, squalene and vitamin E, a sample treatment method which not only can extract saponified substances (fatty acids) but also can extract the accompanied components (non-saponified substances of sterols, squalene, vitamin E and the like) is determined, and the reliable method which can adopt gas phase chromatography for rapidly detecting the fatty acids and the accompanied components is provided for enterprises.

The invention discloses a method for quickly detecting the content of L-glutamine in a fermentation liquor. The method comprises the following steps: (1) selecting a cultivation strain of glutamine for activating culture, and then transplanting the cultured strain to a fermentation medium for cultivation; (2) conducting oscillation and centrifugation on the fermentation liquor to obtain a liquid to be detected; (3) preparing a developing solvent, a color developing agent and an eluant; (4) drawing a standard curve; (5) utilizing the liquid to be detected obtained in step (2) for sample spotting on a thin silica gel plate, carrying out developing, color developing, elution and sampling, utilizing an ultraviolet-visible spectrophotometer to measure a light absorption value, and obtaining the value, corresponding to the light absorption value, on the standard curve drawn in step (4), wherein the value is the content of the L-glutamine in the fermentation liquor. The method can be used for detecting the content of the L-glutamine in the fermentation liquor quickly, and is high in accuracy, fast, simple, low in cost and high in timeliness.

The invention discloses a method for carrying out bulb induction and plant regeneration of wide-leaf albuca namaquensis by flower buds. The method comprises the following specific steps: (1) preparation of a culture medium including a basic culture medium and components of the culture medium at all stages of tissue culture; (2) selection and disinfection of explants; (3) induction and multiplication of bulbs; (4) rooting of strong seedlings; and (5) transplantation. The method disclosed by the invention has the beneficial effects that the direct induction and the plant regeneration of the bulbs are carried out on flower buds of the wide-leaf albuca namaquensis by utilizing a plant-tissue culture technology, and the procedure of tissue-culture operation is simplified, so that a great quantity of high-quality strong seedlings with consistent genetic characters can be obtained in short time, simultaneously, the defects of female-parent scarcity and slowness of conventional multiplication methods are overcome, and the method has the positive significance for both protecting germplasm resources of the albuca namaquensis and industrializing seedling production.

The invention discloses a flexible micro-column ring array for detecting the contractility of a clot and a preparation method and application of the flexible micro-column ring array. The micro-columnring array is composed of a plurality of micro-column rows arranged periodically, each micro-column row is provided with a plurality of micro-column rings, and each micro-column ring is composed of four or more micro-columns forming a ring shape in a surrounding mode, wherein a circular pore with a certain diameter is formed in the micro-column ring, and when the contractility of the clot is detected, whole blood is dropped into the circular pore of the micro-column ring for blood coagulation detection. According to the invention, a whole blood sample is efficiently fixed in the micro-column ring by utilizing the interfacial tension of a solid-liquid-gas system and the resistance of the micro-column; meanwhile, the micro-column is used as a force sensor to measure the contraction force ofa clot in real time, the detection result is high in sensitivity and low in detection cost, and clinical transformation is easy; besides, platelets do not need to be separated from blood, whole bloodcan be used for detection, the influence of other components in the blood on platelet contraction is fully considered, and the result is more objective and comprehensive.

The invention belongs to the technical field of agriculture, and particularly relates to a method for determining the lime application amount in acidified soil remediation. The method includes determination of soil pH increment, lime treatment of soil to be improved, determination of soil pH increment after application of different limes in the soil to be improved, lime application amount model building and determination of the lime application amount in a large field. The method only selects the soil pH as a test index, is simple and easy to implement, and overcomes the defect that an estimation method is not accurate, and more importantly considers buffer characteristics of different soils and the characteristic of large soil pH change after lime application. By means of the method, theamount of lime needed to improve the acidified soil by certain unit can be accurately calculated. The method is suitable for various types of soil and has important application value.

The invention discloses a method for screening a plant variety with a leaf strengthening function. The invention belongs to the fields of breeding of crop high-lighting-effect and high-temperature-resistant variety, and relates to a method for screening a high-light-effect corn variety by a technological system, wherein the technological system is to screen a large amount of corn combination by applying leaf temperature, difference between leaf temperature and air temperature, leaf chlorophyll content, leaf nitrogen content and a fluorescence parameter PI (abs), select about 8 parts of materials, measure the photosynthetic rate by an LI-6400 photosynthesis system at the daily maximum temperature being 35 DEG C or above and select 3 to 4 parts of materials again to measure parameters such as photoresponse and carbon dioxide response. Compared with other breeding methods, the technology has the characteristic of screening a large amount of corn varieties, is suitable for selecting and breeding a high-quality corn variety from a large amount of varieties and has a good application prospect.

The method discloses a gas-hydrate-separation bubbling reinforcing device, a gas-hydrate-separation purifying reinforcing device based on the same and a gas purifying reinforcing method, and relates to the field of coal. The problems that the gas-hydrate-separation rate is low, and the separation concentration and the methane recovery rate are low are solved. By means of the gas-hydrate-separation bubbling reinforcing device, the contact area between gas and an accelerant solution is greatly increased, the content of the gas entering a liquid phase is increased, the separation rate is accelerated, and the gas-hydrate separation concentration and the methane recovery rate are increased. According to the gas-hydrate-separation purifying reinforcing device and the purifying reinforcing method, the temperature is adjusted through a temperature control box, the pressure and the temperature of the gas in a hydrate reaction kettle are monitored through pressure sensors and temperature sensors in real time, and are stored and observed through an industrial personal computer and a data acquisition device in real time, the temperature of the temperature control box and the operating sequence of the device can be conveniently adjusted in time, and the gas-hydrate-separation purifying reinforcing device and the purifying reinforcing method are suitable for purifying other kinds of gas.

The invention relates to a compound Chinese herbal medicine preparation for preventing and treating Newcastle disease, prepared from main materials and auxiliary materials, wherein the main materials of the compound Chinese herbal medicine comprise creeping woodsorrel, negundo chastetree, dutchmanspipe root and the like; and the auxiliary materials comprise corn flour as a dispersant and vitamin C as a stabilizer. The compound Chinese herbal medicine for preventing and treating Newcastle disease simultaneously has double effects on preventing and treating Newcastle disease and has a certain growth promoting effect; when used for prevention, a powder can be mixed with feed for feeding, or an extracting solution can be sprayed and mixed with feed for feeding; when used for treatment, the extracting solution can be drenched or drunk, the medicines in the main materials can be adjusted according to different syndrome types, thus being convenient in use; and the medicinal raw materials have wide sources and low cost.

The invention relates to a preparation method of a graphene oxide thin film, which includes the following steps: dipping a writing brush in a graphene oxide water solution, brushing the graphene oxide water solution on a substrate and heating and drying the substrate to prepare the graphene oxide thin film. The method is simple in operation method and is convenient and quick to carry out. The graphene oxide thin film is controllable in macroscopic size, shape and other parameters and in reduction degree, is effectively reduced in stacking among graphene lamellas, and is enhanced in electric-conductivity.

The invention discloses a method for quickly calculating the static storage capacity of a reservoir based on a DSI technology. The method comprises the steps that first, a topographic surface which is infinitely close to the real is established; second, a program which can automatically calculate the area and the storage capacity of the reservoir is programmed; third, an area and storage capacity variation curve is automatically calculated and drawn. According to the method for quickly calculating the static storage capacity of the reservoir based on the DSI technology, the speed and the accuracy of calculating the static storage capacity of the reservoir can be improved, the storage capacity calculating is made to be not influenced by the types of the topographic surfaces, the time for calculating the storage capacity of the reservoir is greatly shortened, the advantages of being high in efficiency, high in speed and capable of automatically outputting calculating charts and tables are achieved, and a wide application prospect in the filed of calculating of the static storage capacity of the reservoir is achieved.

The invention belongs to the field of nano material preparation and discloses a silicon dioxide nanowire preparation method. Common silicate glass is adopted as raw materials to prepare SiO2 nanowires according to an ammonium hydroxide hydrothermal method. The SiO2 nanowire preparation method is low in raw material cost and simple in manufacturing process, overcomes the defect of complexity, inconvenience or high risk of a traditional method and is conducive to large-scale production.

The invention belongs to the technical field of network protocol vulnerability mining, and particularly relates to a camera network protocol fuzzy test method based on an FSM. According to the invention, the problems of more network protocol vulnerabilities and immature fuzzy test method of the current camera are overcome, and the protocol vulnerabilities can be effectively detected. The originaldata can be automatically generated, and the state transition diagram is automatically generated according to the state transition form. According to the method, the pertinence is higher, vulnerability information of SIP and RTSP protocols can be provided, and security analysts are helped to complete subsequent work.

The invention discloses a combined main body service selecting method based on tabu search and is designed for solving problems of a non-functional attribute combined main body service selection. The method comprises an initial solution construction process and a tabu search process. By using the strong local searching capability of the tabu search, a combined main body service having greatest service quality and meeting a certain service quality attribute restriction can be iterated and found from the aspect of service quality. After the adoption of the method, the combined main body service meeting requirements can be searched quickly, and the combined main body service selecting method has the characteristics of quick constriction and excellent performance, and overcomes the problems of high complexity of an exhaustive method, early-maturing of genetic algorithm, local optimum and the like.

The invention belongs to the field of cable installation, and specifically discloses an intelligent building cable bridge support installation method. The main scheme is that a puncture sleeve is fixed to the end of a cable in a threaded mode, and a pull rope is tied at the head of the puncture sleeve. The pull rope penetrates through a linearly-arranged detection ring, the cable is pulled in through the pull rope and passes through the detection ring, a hoop passes into the inner side of an upper cover through a through hole of the upper cover, so that the hoop clamps the cable, the two endsof the hoop are fixed, and the two ends of the hoop are welded to the upper cover and a bottom cover respectively. The lower portion of a linearly arranged detection rod is fixedly connected to a pullrod, the pull rod is fixedly connected to a piston rod of a push cylinder, and the push cylinder is fixed to the bottom cover. According to the method, the problems of improper methods, low quality,chaotic disorder, and mutual interference in the prior art are solved. In addition, the detection of leakage is facilitated by using the method of cable installation.

The invention discloses a method for obtaining callus and suspension cells under induction of Taxus chinensis test tube plantlet. The method comprises the following steps: (1) seed testa peeling: mechanical cracking is utilized and the testa is peeled manually; (2) explants disinfection: disinfection is carried out for 90 seconds with 70% alcohol and carried out for 12 minutes with 0.1% mercuric chloride, and washing is carried out by 5 times with sterile water for standby; (3) pretreatment of seed: seed soaking is carried out by 1-5 days at normal temperature hermetically with sterile water; (4) zygotic embryo separation; (5) induction of test tube plantlet: embryo is inoculated to a test tube plantlet induced culture substrate; (6) induction of callus; (7) subculture of callus; and (8) suspension culture of callus. The method has the characteristics of being capable of simply, conveniently and quickly obtaining Taxus chinensis callus and utilizing the callus to provide material for the suspension culture of cells of Taxus chinensis or further screen high-yield paclitaxel cell strains to provide high-quality screening material, thereby saving a great quantity of manpower and material resources and improving the labor efficiency.

The invention relates to a man-machine interaction device and method for information technology management consultation. A bottom plate is arranged on one side of the workbench. A vertical rod is fixedly mounted on the bottom plate; a transverse rod is arranged at the top of the vertical rod, man-machine interaction induction equipment is fixedly installed at the bottom of the transverse rod, an induction station limiting area is fixedly installed on the bottom plate below the man-machine interaction induction equipment, the man-machine interaction induction equipment is connected with the networking host through a wire, and a host input module is arranged on the other side of the workbench. The man-machine interaction device special for information technology management consultation is provided, outstanding contribution is made to specific actual operation and interaction experience, the use is convenient by adopting man-machine interaction induction equipment, meanwhile, the device is very good in interaction effect and experience feeling, does not cause faults and misoperation, and has very good social and economic benefits.

The invention relates to a sliding support structure of a mobile working vehicle. The sliding support structure comprises a supporting beam, wherein the supporting beam is connected with a plurality of supporting seats in a sliding manner, and the supporting seats are fixedly connected to the bottom surface of a vehicle compartment; the supporting beam comprises supporting rods and a sliding rod connected with the supporting seats in the sliding manner, and the sliding rod is fixedly connected with the supporting rods in a welded manner; a sliding seat connected with the sliding rod in the sliding manner is arranged on each supporting seat; a check block bending upwards is arranged on one side of each supporting seat; and a limiting space is formed between each check block and the sliding seat. According to the sliding support structure disclosed by the invention, the structure is simple; after the sliding supporting structure is connected with a supporting plate, the sliding support structure can quickly unload light mechanical equipment; a 'drawer type' mobile platform is adopted, workers can conveniently load and fix or unload unmanned aerial vehicles or other similar mechanical equipment only outside the vehicle, and the operation is rapid and convenient, so that the defects that a conventional unloading method and transportation waste time and labor are overcome; and the limiting space is formed between each check block and the sliding support corresponding to the check block, so that the loaded equipment can be prevented from moving to left or right during transportation, and thus the transportation is safe and reliable.

The invention discloses an active power filter based on a nonlinear tracking differentiator and an arithmetic circuit thereof. The filer comprises a voltage loop outputting the difference between themeasured actual value of a DC side voltage and a voltage reference value; a PI controller and a proportional integral controller are connected to the output of the voltage loop for outputting a corresponding reference current; a nonlinear differential tracker connected to the proportional integral controller and capable of more rapidly tracking a reference current and the derivative signal, and filtering the harmonics in the reference current; a phase-locked loop generating a unit sinusoidal voltage signal in the same phase and same frequency with a grid side voltage and detecting the voltagephase on the grid side; and a multiplier connecting with the outputs of the nonlinear tracking differentiator and the phase locked loop to obtain a reference value of the current on the grid side . According to the invention, the dynamic performance of the active power filter is greatly improved under the premise of shortening the reaction time, and the reference current can maximize the suppression of harmonics.

The invention discloses a palm-leaf fan and a preparation process of the palm-leaf fan. Cloth strip metal wires are used as ingredients, a sewing machine and a color coating method are used for replacing the complicated manual sewing, a layer of acetic acid resin is coated on the surface of the palm-leaf fan to be used as a supporting layer, a laser machine is used for carrying out non-contact type work, patterns on a design draft are printed onto the fan surface by pigment electric iron, then, the acetic acid resin is coated to be used as a protection layer, and finally, a bamboo tube is made into a palm-leaf handle. The preparation process of the palm-leaf fan is simple, the efficiency is high, the fan surface stain pigment coating capability is good, the affinity with pasting objects is high, and the images of the fan surface of the made palm-leaf fan are stable.