35results about How to "Small environment" patented technology

The invention discloses water-based UV black ink with super-high solid content and a preparation method thereof. The black ink comprises the following components in percentage by weight: 20%-60% of high-functionality water-based polyurethane acrylate, 5%-8% of compound photoinitiator, 15%-35% of hydrophilic acrylate diluted body or prepolymer, 10%-25% of solvent and 5%-15% of nano-carbon black pigment. The light curing time of the water-based UV black colored paint of the invention is shorter than 5 seconds, the bottom layer can be completely cured, the comprehensive properties of adhesive force, hardness, toughness and the like are excellent, and the water-based UV black colored paint can be widely applied to the fields of ink, wood paint and the like; the solid content is as high as 80%;and the water-based UV black ink has short drying and curing time, simple construction technology and high production efficiency, can be diluted by water or ethanol or other nontoxic solvents for regulating the viscosity, is suitable for various production modes and production requirements, and is environment-friendly and nontoxic.

The invention relates to a laser scanning based vehicle type recognition method for free flow charging. The laser scanning based vehicle type recognition method includes the following steps: by a laser scanning detector, parallelly scanning two sections of a travelling vehicle to acquire measured angle and distance data, wherein the two sections are perpendicular to the road plane and intersect; by the laser scanning detector, uploading the measured angle and distance data to a vehicle type recognition device; by the vehicle type recognition device, calculating to acquire length, width and height of the vehicle and outline information of the whole vehicle; matching the acquired vehicle outline information with a vehicle type classification feature library to acquire a vehicle type to achieve automatic vehicle type recognition. By the laser scanning based vehicle type recognition method, automatic vehicle type recognition of all passing vehicles of free vehicle flows with the average vehicle speed below 120 kilometers/hour can be realized.

The invention discloses a millimeter wave antenna system and a communication device. The millimeter wave antenna system comprises a frame/housing equipped with an antenna slot; a high dielectric coverlayer arranged on the outside of the antenna slot; a signal transmission unit provided on the inner side of the antenna slot; a signal transceiver assembly electrically connected to the signal transmission unit; and an intermediate frequency and baseband processing unit electrically connected to the signal transceiver assembly; The dielectric resonant antenna array of millimeter wave antenna system is composed of the high dielectric cover layer, the antenna slot and the signal transmission unit. The invention provides an antenna system, which has the characteristics of small occupying space,many correctable factors and high working efficiency.

The invention relates to a railway track detection device and a use method. The broken rail detection device comprises two steel rails of a rail-mounted locomotive, and is mainly characterized in that at least a pair of electric short wires are arranged between the two steel rails; the electric short wires and the two steel rails surround into an electrical isolation unit; at least one current sensor is arranged on one steel rail of the electrical isolation unit; and the current sensor is electrically connected with a current signal receiving and processing unit which outputs a broken rail signal to an output device. The invention has the advantages of adopting a direct short-circuit jointless track circuit; the circuit can not be used as the traditional track circuit although a shunt dead section exists; and the jointless track circuit is superior in the broken rail detection aspect because of the simple device thereof.

The invention discloses a scroll plate measuring method and device based on a numerical control motion platform. The scroll plate measuring device comprises a host base, a rotary platform, an overturning clamping part, a two-pole grating scanning double-ball measuring head part, a radial shaft, a vertical shaft and a tangential shaft motion mechanism. A measuring head part adopts a two-pole grating scanning double-ball measuring head structure. The measuring head part matches a four-axis motion platform and a turnover clamping component to realize rapid, efficient and accurate online measurement of the key form and position size of a scroll plate of a scroll compressor of the automobile air conditioner. Interference in the measurement process can be effectively avoided, a coordinate reference of a scroll plate workpiece is established through one-time clamping of the workpiece, and detection software completes rapid analysis of key measurement items such as profile tolerance of inner and outer spiral lines of the scroll plate by adopting an improved polar radius error mathematical model based on polar coordinates. The invention can be used for quickly detecting the form and position errors on a scroll plate production line, the detection result directly reflects machining errors, and machining precision can be controlled in time.

The invention provides a layering machine for layering propagation of plants. The layering machine comprises two half shells (1 and 5), wherein one to two elastic claws (8) and corresponding clamping grooves (7) are arranged on the half shells, so that the two half shells form a hollow shell; two ends of each half shell are provided with a half neck part (3) respectively to form a neck part for enclosing and fixing branches of the plants; the half shells are provided with a feed inlet (2) respectively; and the inner walls of the half shells are provided with a group of drop pits (6) respectively. The layering machine has the advantages that the layering machine can be used repeatedly; management such as water replenishing, fertilizer applying and so on is convenient; the layering machine has good ventilation and drainage performances and accelerates the root growing speed; pocking marks make root systems run through a substrate to and fro, and make root balls compact; and the layering machine is convenient to transport due to small root systems and light weight.

The invention discloses a coaxiality measuring device and method for a large-span shaft hole part. The device comprises: an axis alignment mechanism installed on to-be-detected parts and used for aligning the axis of a hole or a shaft part; a laser source part used for emitting a reference laser beam coinciding with the axis of the hole or the shaft part at one side; and a position display part used for receiving the laser and measuring the coaxiality of the two to-be-detected parts according to the position of the reference laser spot. According to the embodiment of the invention, the laser source part and the position display part are used for detecting the coaxiality of the to-be-detected parts, the structure is simple, and the cost is low; one set of coaxiality measuring devices can besuitable for coaxiality inspection of to-be-detected parts of various hole shafts with different diameters; and moreover, the laser propagation linearity is good, and the coaxiality measuring deviceand method are especially suitable for coaxiality measurement of large-span shaft hole parts.

The invention discloses a pyrisoxazole-cnidium lactone suspension emulsion and a preparation method thereof. The suspension emulsion contains the following components in percentage by weight: 1%-40% of pyrisoxazole, 0.05%-5% of cnidium lactone, 1%-50% of a solvent, 1%-40% of an emulsifying agent, 1%-10% of a dispersant, 2%-4% of a botanical fungicide, 0.1%-10% of a thickener, 1%-5% of an anti-freezing agent, 0.1%-1.0% of an anti-foaming agent, 0.1%-1% of a preservative and the balance being water. The compound preparation can effectively prevent and control diseases and pests of crops (for example, the preparation can simultaneously prevent and control a disease, i.e., blight, and pests, i.e., cotton bollworm, of cotton), and is durable in efficacy. The compound preparation can also effectively prevent and control various diseases on crops, for example the preparation can simultaneously prevent and control white rot, gray mold and powdery mildew on grapes as well as gray mold, leaf mold and powdery mildew on tomatoes; the compound preparation has obvious effects of protecting seedlings and increasing production, is simple in production process, and has labor-saving, time-saving and energy-saving effects, obvious economic, ecological and environmental benefits, and wide development prospect.

The invention provides a copper-based catalyst for preparing methyl glycolate at high selectivity, wherein the catalyst is prepared with a high-specific surface area material as a supporter and copperas an active component through a physical sputtering method in one step. The catalyst is used for a reaction for preparing the methyl glycolate through hydrogenation by catalyzing dimethyl oxalate, wherein the mass content of copper in the catalyst is 5-30% and the balanced being the supporter. The catalyst has the following advantages: (1) the copper is subjected to bombarding of Ar ion, so thatelectron structure of copper is varied, and the copper shows a noble metal-like property, wherein the copper on the catalyst is zero-valent stable copper, which is not liable to be oxidized, so thatthe copper can replace noble metals such as Au and Ag in the ester hydrogenation reaction; (2) the active metal, copper, has high selectivity on the methyl glycolate, so that the catalyst is free of any other additives.

The invention discloses a water-blown warm-mix flame-retardant asphalt mixture and a preparation method thereof. According to the invention, through comprehensive utilization of a water-blown asphalt warm-mixing technology and an asphalt flame-retardation technology, construction temperature of an asphalt pavement is effectively reduced, the safety factor of a tunnel asphalt pavement is increased, and the advantages of energy conservation, emission reduction, greenness, environmental protection, reduction in construction cost, improvement of warm-mixing construction technology for tunnel flame-retardant asphalt pavements and the like are obtained. The invention also provides a design method for the water-blown warm-mix flame-retardant asphalt mixture. The method utilizes the concept of equivalent design of basic mix ratios and technique indexes to improve the traditional design method for the warm-mix flame-retardant asphalt mixture, provides bases for the design of the water-blown warm-mix flame-retardant asphalt mixture and fills a gap in the design method for the water-blown warm-mixed flame-retardant asphalt mixture.

The invention belongs to the breeding technology, and particularly relates to a rubus-chingii seed breeding method. The rubus-chingii seed breeding method includes the following steps that seeds are pretreated and subjected to acid etching, potassium permanganate treatment, gibberellin treatment and low-temperature stratification, then sowing, seedling raising and cultivation are carried out, and rubus chingii can be obtained. The rubus-chingii seed breeding method is simple, economical and rapid, seed dormancy of the rubus chingii is broken, the breeding coefficient is increased, and a rapid breeding system of the rubus chingii is completed.

The invention provides a lifting cabinet type integrated multimedia teaching machine capable of being used in a mobile mode and belongs to the technology of computer multimedia device development. The machine is mainly composed of a machine cabinet (1), a machine cabinet case (2) which is called a machine case for short and an integrally-arranged electric lifter. The machine cabinet and the machine case are connected into a whole through the lifter, the core components such as a displayer, a voice box, a power amplifier, a computer, a center control system and an externally-connected port are installed in the machine cabinet in an integrated mode and the machine cabinet can be lifted from the machine case or descend to the machine case according to the requirements; a lockable top cover and a base are arranged on the machine case and universal wheels are installed on the lower face of the base. The lifting cabinet type integrated multimedia teaching machine has the practical advantages that the integration level is high, the seeing and hearing effect is good, the machine can be used in the mobile mode, management is convenient, the functions are complete, control is convenient, and the machine can be widely applied to various indoor and outdoor occasions for teaching, training, meeting, propaganda, entertainment activities and the like.

The invention discloses a method for measuring the light resistance performance of cigarette wrapping paper. First use a spectrophotometer to measure the original color difference of the main color block of the cigarette wrapping paper to be tested, then place the sample in a preheated exposure box for 6 hours and then measure the color difference value after exposure, and finally use the cigarette wrapping paper The hue change (color difference value) before and after exposure to the sun is used to characterize the lightfastness of cigarette wrapping paper. This method is less affected by environmental and human factors, and the data is more objective and fair and can be quantified. The measurement time is short, which is beneficial to guide production. The repeatability and consistency of the determination results are superior to other test methods.

The invention provides a micron-sized water-swelling suspension liquid modifying and flooding agent and a preparation method thereof. The modifying and flooding agent comprises the following raw materials in parts by weight: 50-650 parts of calcium chloride, 5-20 parts of dodecyl trimethyl ammonium chloride, 0.5-1 part of dimethicone, 500-800 parts of a micron-sized water-swelling agent, and 1,000 parts of water. The micron-sized water-swelling suspension liquid modifying and flooding agent provided by the invention is free of dust when used on the spot, and is relatively small in effects on health of operating personnel and the environment; compared with an existing product prepared by an emulsion polymerization method, the cost of the micron-sized water-swelling suspension liquid modifying and flooding agent prepared from a saline solution is reduced by over 24%; and the micron-sized water-swelling suspension liquid modifying and flooding agent has the effects of participation and profile control.

The invention discloses a water-rich sand layer pre-stressed anchor cable installation method which comprises a field environment exploration stage, a detection stage, an installation scheme making stage and an actual installation stage. The water-rich sand layer pre-stressed anchor cable installation method comprises the following installation steps of 1, the field environment exploration stage,specifically, understanding the environment of an installation field through field investigation; 2, the detection stage, specifically, sampling and detecting the water content of a sand layer and detecting the hardness of a fixed rock layer; 3, the installation scheme making stage, specifically, making an installation scheme according to a detection result in combination with a field explorationcondition; and 4, the actual installation stage, specifically, carrying out actual construction according to the formulated installation scheme. According to the method, the detailed installation scheme is designated before installation, the sandstone water content of the installation position and the strength of the fixed rock layer are analyzed, the influence of the environment and address factors on the stability of an installed anchor cable in the installation process can be effectively eliminated, and it is ensured that the installed anchor cable is more stable.

The invention discloses a crawler-type paperboard dryer. The crawler-type paperboard dryer comprises a support. Driving devices are fixedly installed at the two ends of a middle layer of the support correspondingly and connected with a conveyor belt. The conveyor belt is a closed annular conveyor belt. A plurality of support assemblies are further fixed to the middle layer of the support and located in the middle of the ring of the conveyor belt. A plurality of light pipes are installed on the support and located in the middle of the ring of the conveyor belt. A fixed transverse rod is fixed to a top layer of the support. A plurality of exhaust fans are installed on the fixed transverse rod and located above the conveyor belt. The light pipes are electric heating pipes. The crawler-type paperboard dryer can meet the requirements of different environments and different humidity and can operate automatically, mass continuous production can be achieved while fast dehumidifying of pasted paperboards is ensured, and the crawler-type paperboard dryer is influenced little by environments and seasons.

The invention discloses a fireproof powder paint which is composed of the following components in parts by weight: 10-20 parts of bisphenol F epoxy resin, 30-45 parts of aliphatic glycidol ether epoxy resin, 15-18 parts of poly(methyl) acrylic resin with free carboxyl group, 15-20 parts of FEVE fluorocarbon resin, 4-8 parts of ammonium polyphosphate, 1-2 parts of magnesium carbonate, 4-8 parts of rubber powder, 8-12 parts of carbon black, 3-5 parts of aluminum powder, 3-5 parts of iron oxide red, 5-8 parts of curing agent, 1-2 parts of stabilizer and 1-2 parts of leveling agent. The powder paint has the advantages of moderate volume resistance, high surface resistance and favorable fire resistance.

The invention discloses a device for supplying power by using gravity, which comprises a container chamber containing a high-density liquid, a gravity chamber, a rotating impeller, a plurality of gravity balls, and a control device, wherein, the lateral surface of the lower part of the container chamber is provided with an access hole provided with an automatic valve, the middle upper part of the container chamber is provided with an automatic cover provided with an induction device, and the outside wall of the container chamber at the upper part of the automatic cover is provided with a piston; the gravity chamber is connected with one side of the access hole of the container chamber, the bottom of the gravity chamber is provided with the induction device, the lower part of the gravity chamber is provided with an automatic sealing device which can seal the access hole of the container chamber at the lower part of the gravity chamber to form a closed chamber, one side of the closed chamber opposite to the access hole of the container chamber is provided with the piston, and the outside wall of the gravity chamber is provided with an inlet; the blade of the rotating impeller is positioned in the gravity chamber by the inlet; the plurality of gravity balls can float in the high-density liquid; and the control device is used for receiving the signals of the induction device and controlling the opening and closing of the automatic cover, the automatic valve and the automatic sealing device and the extension of the piston. The device is influenced little by environments and supplies power stably.

The invention relates to a small-size hand-hold deep small hole composite deburring device used for complicated case parts, which belongs to a mechanical processing tool. The deburring device comprises a work table, a fixed support frame, a vibration generator and a vibration converter provided with a deburring tool, wherein the fixed support frame and the vibration generator are arranged on the work table, the vibration converter with the deburring tool is arranged on the fixed support frame through strip steel, he vibration converter with the deburring tool is connected with the vibration generator, a micro powder grinding container is arranged on the work table, a water container is higher than the micro powder grinding container and is arranged on the work table, the deburring tool is connected with the vibration converter, the deburring tool is a cylindrical slender metal rod, the center of the front end of the metal rod is provided with a penetrated open rectangular groove with the width between 0.25 mm and 0.3 mm, and the depth of the rectangular groove is 3 to 5 times of the diameters of the metal rod. The invention is applicable to the deburring of deep small holes with the length-to-diameter ratio greater than 40 and the diameter phi smaller than 3 mm, and the processing efficiency is improved by more than 50 to 70 percent.

The invention discloses a sperm piRNA and a sperm protein MitoPLD as biomarkers for detecting and predicting male infertility. The biomarkers include 10 piRNAs (mainly piR-1207 and piR-2107) and the MitoPLD protein. The piRNA combination and the MitoPLD protein can be used for detection and prediction of sperm motility. According to the sperm piRNA and the sperm protein MitoPLD as the biomarkers for detecting and predicting the male infertility, spermatozoa are more easily obtained without other tissues, and the sperm piRNA and the sperm protein MitoPLD as the biomarkers for detecting and predicting the male infertility belong to non-invasive examination; the sperm piRNA and the MitoPLD protein can reflect pathological and physiological conditions throughout spermatogenesis at a molecularlevel, and are used as an auxiliary detection index to improve accuracy of detection, and provide potential targets for treatment of male reproductive dysfunction.

The invention discloses a source pollution control method for an acidic coal gangue storage yard. The source pollution method for the acidic coal gangue storage yard comprises the following steps of: a, preparing acidic coal gangue storage yard antibacterial agent; b, spraying on the surface of the coal gangue storage yard; and c, carrying out daily maintenance or subsequent depth treatment. The source pollution control method for the acidic coal gangue storage yard disclosed by the invention can be used for effectively inhibiting acid production by acidic coal gangue oxidization and digestion of a plurality of polluted substances from the source, so that the problems that the existing coal gangue storage yard commonly has high soil replacement covering cost, the common alkali neutralization method and the fertilizer application treatment are easy to lose effect, the end treatment is lasting and higher in treatment cost, and severe environment interference and ecological hazards are continuously generated by stacking much coal gangue are solved. Moreover, the antibacterial material resource is wide, the cost is low, the construction process is simple, the operability is strong, the efficiency is high, the secondary environment pollution risk is small, and the environment benefits, the economic benefits and the social benefits are better, so that the source pollution control method is suitable for large-area application and implementation.

The invention provides an automobile rear-end collision prevention active safety system. The automobile rear-end collision prevention active safety system comprises a distance measuring module mountedon an automobile head, a sound and light alarm installed on an automobile instrument board and a control module installed under the instrument board. The control module is separately connected with the sound and light alarm and the distance measuring module, and the control module receives information detected by the distance measuring module to control the sound and light alarm to issue an alarm. The alarm combination of sound and light creates visual and audible double stimulus to a driver to attract attention of the driver. The detection performance of radar distance measuring is not affected by the shape and color of an object, the detection accuracy is less affected by weather and environments, the distance measuring distance is far and the precision is high, and the radar distance measuring can better meet the requirements of the automobile rear-end collision prevention active safety system.

The invention discloses a fire retardant coating for an aluminium plate and a production process tereof. The fire retardant coating catalyst is prepared form sodium silicate, simethicone, an adhesionagent, an annexing agent, solvent, a catalyst, a thickening agent, an antibacterial agent, inorganic powder, a film-forming agent, an acid donor, a foaming agent, a synergistic agent, inorganic fillers, a carbonization agent, epoxy resin and cellulose ether; the production process comprises the following steps of raw material preparation, dispersion, grinding, inspection and package; the fire retardant coating is good in environment protection, can continuously exert a flameproof protection effect, is wide in application range, better in fireproof performance and stronger in adhesive strength,and has better chemical corrosion resistance, better heat resistance, better acid-base resistance and better electrical insulating performance; the fireproof performance is slightly affected by timeand environments, the coating further has the advantages of lasting fire resistance, high inflaming retarding efficiency and the like, the flame retardant effect of the coating is strengthened, the effective fireproofing time of the coating is prolonged, the preparation method is simple and convenient, and the efficiency is high.

The invention discloses new application of bacillus pumilus HR10 in prevention and treatment of forest diseases, and belongs to the technical field of biological prevention and treatment. A further test on the rhizosphere growth-promoting bacterium bacillus pumilus HR10 obtained in the earlier stage of the laboratory finds that the rhizosphere growth-promoting bacterium bacillus pumilus HR10 has an antagonistic effect on S. salina of pine wilt tip pathogenic bacterium; 1) HR10 strain fermentation broth can cause S. salina vegetative body mycelium deformity, spore germination delay and myceliumgrowth capability inhibition, and can destroy normal synthesis of pathogenic bacteria cell membranes and cell inclusions; and 2) the HR10 strain can be colonized on pine trees and gathered around coniferous stomata to prevent pathogenic bacteria hyphae from invading, and the hyphae are thin and weak. In a greenhouse test, the prevention and treatment effect of the bacillus pumilus HR10 on the pine wilt reaches up to 90%. Therefore, the bacillus pumilus HR10 has a good application prospect in prevention and treatment of pine shoot blight.

The invention belongs to the technical field of structural damage detection and reinforcement, and particularly relates to a carbon fiber structure reinforcement method. Before pasting a carbon fibercloth, the carbon fiber cloth is pre-soaked with an epoxy resin solution, the carbon fiber cloth after immersion is pasted on the surface of a concrete crack with an epoxy resin adhesive, and the carbon fiber cloth is pasted in the direction of the tension or in the direction perpendicular to the cracks. The carbon fiber structure reinforcement method solves the problem that in the prior art, thestrength, rigidity, stability and durability of a structure and a member cannot be well improved in the prior art, and has the beneficial technical effects of improving the strength, rigidity, crack resistance and elongation of the structure and being good in anti-seismic effect and better in reinforcement effect.

In order to solve the problem of large positioning deviation of an existing positioning method for an explosion point of an artificial precipitation enhancement hail suppression bomb, the invention provides an artificial precipitation enhancement hail suppression bomb sound positioning system and a positioning method. According to the method, a positioning mode based on the fusion of the arrival distance difference and the arrival angle of the hail suppression bomb explosion point sound wave signals is adopted, the influence of clock stability and environmental factors is small, and thereforethe positioning deviation is small. In addition, a plurality of single microphone nodes are arranged, so that there are many redundant parameters and parameters for position calculation, and the position estimation of the explosion point of the precipitation enhancement hail suppression bomb is more accurate.

The invention provides an antenna assembly and a wearable device. The antenna assembly comprises a conductive middle frame, a coupling branch knot and a feed element. The conductive middle frame forms an accommodating space in a surrounding manner, and comprises a radiator which is used for receiving a first GPS signal. The coupling branch knot and the radiator are arranged at an interval, the coupling branch knot is used for receiving a second GPS signal, and a frequency band corresponding to the second GPS signal is different from a frequency band corresponding to the first GPS signal. The feed element is arranged in the accommodating space, one end of the feed element is electrically connected with the feed point of the radiator and is electromagnetically coupled with the coupling branch knot, and the other end of the feed element is used for being electrically connected with a radio frequency module. The wearable device comprises a display screen, a circuit board and the antenna assembly. The antenna assembly and the wearable device provided by the invention are high in positioning precision.

The invention discloses a differential protection fault detection method, a differential protection fault detection device and a differential protection fault detection system of an energy storage tramcar super capacitor charging device based on a BP neural network. The method comprises the following steps: collecting real-time voltage and current data at the input side of the charging device, real-time voltage and current data at the output side of the charging device, voltage and current fault data at the input side of the charging device and voltage and current fault data at the output sideof the charging device; calculating to obtain input-output current differential data based on the collected real-time data; taking the collected real-time data and current differential data as inputlayer neuron data of a pre-built BP neural network model to obtain output data of the BP neural network model; and judging the positions of fault points according to the output data of the BP neural network model. The detection accuracy is high, the overhaul time can be shortened, and the troubleshooting work efficiency of the fault points is improved.

The invention discloses a splayfoot detection prompt device based on a surface electromyogram technology, and belongs to the field of health care devices. The splayfoot detection prompt device comprises a leg strap, the leg strap is in a annular shape, electromyogram signal detection electrodes, a signal processing module and a signal execution module are arranged in the leg strap, the electromyogram signal detection electrode and the signal execution module are both connected to the signal processing module, and the electromyogram signal detection electrodes are distributed at the inner side of the rear part of the leg strap and used for detecting splayfoot posture information; the signal execution module is used for generating a prompt signal for a user with respect to the detected splayfoot posture information. The splayfoot detection prompt device based on the surface electromyogram technology combines electromyogram detection and a retractable leg strap, is high in detection accuracy and convenient to use, and can well help the user to correct a splayfoot posture.

The invention belongs to the technical field of fire alarm, and discloses a fire alarm system which comprises a fixed disc, mounting grooves are formed in the outer side face of the fixed disc at equal angles, smoke detectors are movably mounted in the mounting grooves, a power connection box is arranged in the middle of the fixed disc, and connecting wires are fixedly mounted at the bottom ends of the smoke detectors. Detection is carried out normally, and when a smoke detector detects a smoke signal, a chemical agent in an agent box is started rapidly through an electric signal to generate a chemical reaction, so that power is provided to drive a protection assembly to move to the outer side face of a fixed disc; the smoke detector is protected by the fireproof and heat-insulating material, so that the phenomenon that the smoke detector of a traditional fire alarm system is damaged due to temperature rise of a fire scene and smoking of smoke is avoided, the property loss when a fire occurs is reduced, a quick response can be made to the fire, and the fire alarm system is low in cost and suitable for popularization.