47results about How to "The method is safe and efficient" patented technology

The invention relates to the technical field of animal product processing and in particular relates to preserved meat and a pickling method of the preserved meat. The preserved meat is obtained by pickling pork by using edible salt, white spirit, peppers, anises, cloves, tea, white sugar and nitrate. The pickling method comprises the steps of (1) pretreatment; (2) immersing;(3) salt frying and pickling; (4) air-drying; (5) fumigation-drying; (6) cooling; and (7) package. According to the preserved meat and the pickling method of the preserved meat, the using amount of pickling ingredients is small, so that the conventional flavor and the color of the preserved meat are guaranteed; the preserved meat is brown, transparent and shiny, is the same in reality as in appearance and smells delicious; the good smell can be kept for a long time; the preserved meat is tender and fat but not greasy; furthermore, the pickling flavor is strong; lean is kermesinus, and fat is milk white; meanwhile, the salt content is only 1.6-2 percent; people do not feel seriously thirsty after eating the preserved meat. The preserved meat is immersed in boiled tea water, so that the meat has natural, fresh, cool and pleasant tea flavor; fumigation is executed by combusting tea tree branches, so that the natural tea fragrance of the preserved meat is enhanced.

The invention discloses a portable photo-thermal seawater desalination hollow fiber membrane, a preparation method, a device and application. The preparation method comprises the following steps: 1) dispersing and dissolving a hydrophilic polymer and nano-particles in a buffer solution with the pH value of 8.5 to prepare a uniform solution, circularly washing the hollow fiber membrane with the uniform solution for 1-24 hours, and conducting cleaning and drying for later use to prepare the hollow fiber membrane with the super-hydrophilic inner surface, wherein the ratio of the hydrophilic polymer to the nano-particles is (1-20):(0-20); and (2) putting the hollow fiber membrane with the super-hydrophilic inner surface obtained in the step (1) in 0.1-20wt% photo-thermal modified material solution atmosphere, and conducting treating for 1-24 hours in manners of surface adsorption, surface vapor deposition, surface cross-linking fixation, suction filtration and / or coating modification, so as to prepare the hollow fiber membrane with the super-hydrophilic inner surface and the photo-thermal outer surface. The three-dimensional hollow fiber membrane is selected as a base material, and the photo-thermal seawater desalination hollow fiber membrane obtained through inner / outer surface modification can realize photo-thermal seawater desalination.

The invention discloses a treatment process of acid-containing wastewater. Organic matter and bromine in wastewater are removed through two steps of resin adsorption, and clean concentrated sulfuric acid with concentration of about 50% and condensate water basically containing no impurities are obtained after obtained output water is distilled through a film. The process is simple in procedure, mild in reaction condition, easy to operate, remarkable in effect and good in economic benefit.

The invention discloses a one-step preparation method for white light-emitting carbon dots, and relates to the field of luminescent nanomaterials. The white light-emitting carbon dots are prepared byusing the following method: in a constant temperature oven, dissolving o-phenylenediamine and catechol at different ratios in an alcohol solvent which includes methanol, ethanol, propyl alcohol, butylalcohol, pentanol and other alcohol, packaging the mixture into a reaction kettle, controlling the temperature of the oven at 140-240 DEG C, and performing a solvothermal reaction for 4-48 hours so as to obtain fluorescent carbon dots with luminescent peaks covering 400-700 nm, wherein the obtained fluorescent carbon dots includes the white light-emitting carbon dots which have CIE chromaticity coordinates of (0.33, 0.33). The white light-emitting carbon dots prepared by using the method has excellent optical properties, a simple preparation method, easily available materials and low cost, and can be directly added to epoxy resin as an encapsulating material of diodes so as to prepare a white light LED device.

The invention discloses a treatment method for condensed wastewater in the disperse blue 56 production process. The treatment method comprises the following steps: heating the wastewater to be 25-100 DEG C, performing heat preservation reaction for 0.5-8 ours, adjusting the wastewater to be acidic, performing acid precipitation till no precipitate is generated and filtering to obtain a filtrate I; adding a primary amino compound into the filtrate I, reacting till no gas is generated, adjusting the mixture to be alkalic, introducing ozone to oxidize for 0.5-4 hours, then adding hydrogen peroxide, performing stirring reaction for 0.2-1 hour and filtering to obtain a filtrate II; concentrating and separating the filtrate II to obtain organic salt. The treatment method for the condensed wastewater in the disperse blue 56 production process is a treatment process taking pre-treatment, acid precipitation and oxidation-concentration as a main line, specially aims at the wastewater generated in the condensation process of a disperse blue 56 production process and can decompose organic matters remaining in the wastewater and remove the COD (Chemical Oxygen Demand) and the chromaticity in the wastewater step by step in a targeted way.

The invention discloses a treatment method of waste water generated in a condensation reaction during a disperse blue 56 production process. The method comprises the following steps: heating waste water to 25-100 DEG C, keeping the temperature for 0.5-8 hours, adjusting the pH value to acidity, carrying out acidification till no deposition generates, and filtering the waste water in order to obtain a filtrate I; adding a primary amine compound into the filtrate I, and carrying out a reaction till no gas generates; oxidizing the waste water by using a Fenton reagent oxidation process, an ozone and hydrogen peroxide oxidation process or a combination of the two processes, in order to obtain a filtrate II; condensing and separating the filtrate II, in order to obtain inorganic salt. The processing technology uses 'pretreatment-acidification-oxidation-condensation' as the mainline, and aims at waste water generated in the condensation process during the disperse blue 56 production process; residual organic matters in the waste water are gradually and targetedly decomposed, and COD and chroma of the waste water are removed.

The invention discloses a preparation and regulation method of high-chromaticness fluorescent carbon nanodots, and relates to the technical field of luminescent nanomaterials. The method comprises thefollowing steps: dissolving a diamine compound and a phenol compound in a solvent A for mixing, loading the mixture into a reaction kettle, and controlling the temperature at 100 to 300 DEG C to perform a solvothermal reaction for 2 to 48 hours to obtain high-chromaticness fluorescent carbon nanodots; then purifying. The CIE chromaticity coordinate of the high-chromaticness fluorescent carbon nanodots is (0.33, 0.33), the CRI value is up to 93, the CCT is 5453K, standard white light emission is realized, the fluorescent spectrum range is in a coverage range of 380 to 700 nm, and the matchingdegree with a standard sunlight spectrum can be up to 85 to 114 percent.

The invention relates to a distributed multi-authorization-party ciphertext policy attribute-based encryption method for medium confusion, which is characterized in that when a new attribute authorization center is added into a system, the new attribute authorization center is secretly distributed with a pseudorandom function PRF (.). In order to prevent collusion of users who possess all relevantattributes in a certain relevant attribute management domain, a trusted medium (MDR) is employed in this system. A data owner generates a ciphertext CT including a obfuscation function. Because the secure DO is used, online interaction does not need to be maintained. Similarly, the DO transmits a key to the MDR, where the key is a function variable for receiving a key skU obtained by the user U from the MDR. The skU is calculated from a PRF (.), a GidU of U, or the like. U has the ability to calculate a function, but does not reveal the internal program secret. Wherein I represents a set of AAs serial numbers of an attribute authorization center for managing U attributes, if the identity IDU of U is confirmed, a corresponding private key USKj is issued to the user U, and the MDR sends a private key skU to the user U. And finally, the U decrypts the ciphertext CT by using USKj (j belongs to I).

The invention relates to an obstacle recognition and avoidance method. The method comprises: a motor unit works according to first motor torque control information; an electric power steering unit works according to first corner control information; a central processing unit analyzes environmental information to determine whether the environmental information includes first obstacle information orsecond obstacle information; when the first obstacle information is included by the environmental information, the motor unit works according to second motor torque control information and then worksaccording to the first motor torque control information, and the electric power steering unit works according to second corner control information and then works according to the first corner controlinformation; and when environmental information includes the second obstacle information, the motor unit works according to third motor torque control information and then works according to the first motor torque control information, and the electric power steering unit works according to the third corner control information and then works according to the first corner control information.

The invention discloses a disease prevention method of increasing the content of phenolic substance in strawberry fruit, and belongs to the technical field of crop cultivation. The method comprises the steps that the strawberry plants are UV-C irradiation treated once every 2-4 days beginning from the flowering period and continuing until the fruiting period; the conditions for the UV-C irradiation treatment are the following: the irradiation dosage amount is less than 0.75 kJ / m2, the irradiation time is less than 70 s; after the UV-C irradiation treatment is completed, the strawberry plants need to be shaded from light for larger than or equal to 8 hours. According to the disease prevention method, the strawberry plants are regularly UV-C irradiated in the flowering and fruiting period, the contents of anthocyanin and flavonol and other phenolic substances in strawberry fruits are significantly increased, meanwhile the antioxidant ability of the fruits is increased; the low dosage UV-C irradiation combined with light shading treatment method is utilized, physiological metabolisms related to the course of disease of the strawberry plants are induced, the anti-disease ability of the strawberry plant per se is effectively increased, and the incidence rate of the natural diseases of the strawberries is significantly decreased.

The invention provides a hatching method of black bottom soft-shell turtle eggs and relates to the technical field of aquaculture. The hatching method comprises the following steps: (1) a black bottomsoft-shell turtle egg preparation stage; (2) a hatching stage; (3) a phase after hatching. By adopting the hatching method of the black bottom soft-shell turtle eggs, provided by the invention, eachstage of hatching is scientifically and finely treated; the black bottom soft-shell turtle eggs hatched by the method provided by the invention have high hatching rate and short hatching time; the resistance of newly born young black bottom soft-shell turtles is strong and the morbidity is low; the method is safe and efficient, is suitable for large-scale hatching and is worthy of being popularized.

The invention relates to a construction method for a stable top plate-coal pillar structure along an empty coal roadway through fully-mechanized caving. The stable top plate-coal pillar structure comprises a tensile anchor cable, a circular truncated cone type baffle disc, a Z-shaped locking tray, a special-shaped quadrilateral tray, a groove cap, a mounting rod, an expanding agent and a hole sealing agent, wherein expanding and fracturing boreholes are formed in a top plate, near a non-stoping roadside, of a mining roadway, slits are cut on the two sides of the boreholes, the tensile anchor cable, the expanding gent, the hole sealing agent and the circular truncated cone type baffle disc are installed in the boreholes, thick top coal is cut on the non-stoping roadside, a locking anchor cable and the Z-shaped locking tray are installed after the slits, and after the fracturing boreholes enter a goaf, the tensile stress on the upper side of a base top at the side region of a working face is remarkably increased, the expansion force of the expanding agent enables a basic top to substantially break along the fracturing boreholes, roadway driving along the goaf is carried out on an adjacent side coal body, a coal pillar side shoulder socket stabilizing anchor is installed on the adjacent side coal body, and the roadway top plate and a coal pillar are located under the protection ofa stable structure of a base top cantilever beam, so that the top plate-coal pillar structure along the empty coal roadway through fully-mechanized caving is constructed, and the method has importantand wide application value.

The invention discloses a net rack mounting construction method. The net rack mounting construction method comprises the following technological processes that a net rack supporting point is measuredand positioned; a raw material is rechecked; a basic net rack striding lower chord bolt ball and a lower chord are mounted; a basic net rack striding upper chord bolt ball, an upper chord and a web rod are mounted; basic net rack striding lifting is carried out; basic net rack striding in place and support connecting are carried out; the rest of the net rack is mounted in bulk in high altitude; oil paint is repaired; and acceptance inspection is carried out. According to the construction method, the problems that the side around a construction plant is narrow, and consequently a car is hard tomount and hoist can be overcome, net rack mounting construction is completed in limited space, and the method is efficient, safe and worthy of popularization.

The invention belongs to the field of enzyme activity inhibition and in particular relates to a method for lowering the activity of autolytic enzymes of sea cucumbers by ultrasonic-assisted electrolyzed water. The method comprises the following steps: preprocessing, performing ultrasonic-sub-acidic electrolyzed water treatment, performing secondary impurity removal, and packaging for storing or subsequently processing. The purposes of changing the internal pH value of the sea cucumbers and lowering the activity of the autolytic enzymes of body walls and intestinal tracts of the sea cucumbers are achieved through the ultrasonic-assisted sub-acidic electrolyzed water treatment. The method has the advantages that the sterilization effect is remarkable, the dissolving-out quantity of TCA-soluble oligopeptide, total sugar and reducing sugar is low, and the enzyme activity survival rate of the autolytic enzymes is lower than 15%.

The invention discloses preserved pork. The preserved pork is prepared from the following raw materials in parts by weight: 100-200 parts of streaky pork, 5-10 parts of table salt, 3-5 parts of whitespirit, 0.5-1 part of Chinese prickly ash, 0.5-1 part of star aniseed, 0.5-1 part of cloves and 0.5-1 part of sweet wine. A method disclosed by the invention is safe and efficient and ensures the traditional natural color of preserved pork, the preserved pork has a charred yellow color, transparency, brightness, uniformity in exterior and interior, diffuse fragrance, mellow and lingering taste andfine and tender meat, the preserved pork is fat but not greasy, and the meat product has a strong preserved meat flavor; the branches and trunks of tea trees are used for performing smoking with firein a smoking and drying process, thereby increasing the natural tea aroma of the preserved pork; and a preparation process of the preserved pork is simple and the preserved pork has good mouthfeel and long preservation time.

The invention provides a hydrogel mask taking vinasse melanin and poplar bud total flavonoids as main raw materials. The hydrogel mask comprises gel, a flexibilizer, a skin conditioner, an emulsifier, a transdermal penetration enhancer, a stabilizer, an adhesion enhancer, a pH regulator and water, the skin conditioner comprises vinasse melanin and poplar bud general flavone. According to the prepared whitening, moisturizing, high-elasticity, support-free and environment-friendly hydrogel mask, the adopted matrix raw material components are natural, green and harmless biomacromolecules and agricultural and sideline product extracts which are good in biocompatibility and excellent in skin affinity, the mask is safe and harmless to the human body, it is guaranteed that the mask matrix is free of sensitization, and the mask can be used for whitening, moisturizing, moisturizing and the like. The prepared mask has the characteristics of good adhesion and fitness, excellent stretchability and toughness, excellent moisturizing and whitening effects, good stripping integrity and the like. The vinasse and poplar bud agricultural and sideline product resources with a large inventory can be comprehensively utilized, the production cost can be reduced, and the economic benefits of the vinasse and the poplar buds are increased.

The invention provides a preparation method of high-purity tellurium diethyl, comprising the steps of S1, cooling tellurium tetrachloride to -20 DEG C to -70 DEG C in a protective gas atmosphere, dropwise adding ethyl magnesium halide, then heating to -60 DEG C to 0 DEG C, stirring and reacting for 1-5 h, heating to 10-30 DEG C, and continuing to stir for 1-5 h to obtain tellurium diethyl mixture; S2, in the protective gas atmosphere, distilling the tellurium diethyl mixture firstly, distilling secondly, and rectifying under reduced pressure to obtain tellurium diethyl having a purity of 5N and above; the tellurium tetrachloride solution is an organic solution formed by dissolving tellurium tetrachloride an organic solvent. The preparation method is simple to perform, the yield of crude tellurium diethyl is high, the purified tellurium diethyl has the purity reaching 5N and above, and the preparation method is good in safety and high in efficiency.

The invention discloses a wind-resistant locking device for a final closure of steel truss beams erected by hole and an method. The wind-resistant locking device is used for temporarily locking an erected A span steel truss beam and a B span steel truss beam to be erected and comprises two telescopic arms, a rear cross beam and two pushing mechanisms, wherein the two telescopic arms are respectively arranged on the two sides of a diagonal member of the A span steel truss beam along a transverse direction of bridge, and each telescopic arm comprises an outer sleeve, an inner sleeve and a driving mechanism; the outer sleeve is arranged on an A span lower chord member of the A span steel truss beam, and the inner sleeve is partly positioned in the outer sleeve; the driving mechanism is arranged in the outer sleeve, is connected with the inner sleeve and is used for driving the inner sleeve to move along a longitudinal direction of bridge; the rear cross beam is connected with the two outer sleeves; a containing area used for containing a B span lower chord member of the B span steel truss beam is formed between the inner sleeves of the two telescopic arms; and one ends of the two pushing mechanisms are respectively fixed onto the two inner sleeves and are positioned outside the outer sleeves, and the other ends of the two pushing mechanisms can extend or retract towards the containing area along the transverse direction of bridge. The wind-resistant locking device can improve the overall wind resistance during erection of the steel truss beams.

The invention discloses a verification code short message verification method and device, and relates to the technical field of communication, and the method comprises the steps: receiving a verification code short message transmitted by a server; analyzing the verification code short message to obtain an application identification code and verification code information in the verification code short message; and querying a terminal application corresponding to the application identification code according to the application identification code, and sending the verification code information to the terminal application, so that the terminal application performs user identity verification by using the verification code information.

The embodiment of the present invention discloses a virtual SIM card parameter management method, a mobile terminal and a server, including: sending an HTTP request carrying device identification information and an algorithm public key to the management server, so that the management server information to assign SIM card parameters to the mobile terminal and use the algorithm public key to encrypt the SIM card parameters; receive the encrypted SIM card parameters sent by the management server; use the algorithm corresponding to the algorithm public key The private key decrypts the encrypted SIM card parameters, and performs network registration through the decrypted SIM card parameters to establish a mobile Internet network. By adopting the embodiment of the present invention, the method of obtaining the encrypted SIM card parameters from the server through the HTTP request is more efficient and safe.

The invention discloses a method for assisting the electrolyzed water soaking of sea cucumbers by ultrasonic waves. The soaking of selected dried sea cucumbers or fresh sea cucumbers which are directly processed by belly cutting, washing and pre-boiling is assisted by the ultrasonic waves. The assisting time, temperature, frequency and power of the ultrasonic waves in the soaking are controlled, and clean water which is used in the soaking process is replaced by weak-acid electrolyzed water, thereby realizing the effects of killing bacteria, improving textures and shortening soaking time, and obviously improving the quality of the product. The method has the advantages of rapid soaking, remarkable sterilizing effect, large improvement on the textures of the sea cucumbers, decrease of residual heavy metal content, preservation of the nutrient substances of the sea cucumbers to a great extent, and capability of prolonging shelf life.

The invention provides a graphene enhanced photo-thermal evaporation membrane, a membrane assembly and a sewage concentration treatment device. The graphene enhanced photo-thermal evaporation film is a hollow fiber film, graphene of a two-dimensional sheet structure is evenly distributed on the inner surface, the outer surface and the section of the photo-thermal evaporation film, the photo-thermal evaporation film is of a gradient ordered pore structure, the pore diameter of the photo-thermal evaporation film is decreased from the inner surface to the outer surface, and the average pore diameter of the photo-thermal evaporation film is less than 30 nm. Graphene with high strength, excellent hydrophobic property, photothermal conversion and heat-conducting property is used as a raw material, preparation of a photothermal modified material is realized through a one-step method, and a sewage concentration treatment device with high specific surface area and efficient photothermal conversion is designed, so that efficient solar energy driven photothermal evaporation concentration is realized.

The invention discloses a method for assisting in fish glue soaking by combining ultrasonic waves with microwave vacuum frying. According to the method, microwaves are adopted for assisting in an oilsoaking process of the fish glue, ultrasonic waves are adopted for assisting in softening and oil removing processes, and the time, the temperature, the frequency and the power of the microwaves and the ultrasonic waves for assisting in soaking are controlled, so that the effects of shortening the soaking time, carrying out sterilization and improving the texture are achieved, and the quality of products is obviously improved. The method provided by the invention has the advantages of quick soaking and remarkable sterilization effect, can improve the texture of the fish glue, and can effectively reduce the loss of nutrient components in the soaking process.

The invention belongs to the field of enzyme activity inhibition and in particular relates to a method for lowering the activity of autolytic enzymes of sea cucumbers by ultrasonic-assisted electrolyzed water. The method comprises the following steps: preprocessing, performing ultrasonic-sub-acidic electrolyzed water treatment, performing secondary impurity removal, and packaging for storing or subsequently processing. The purposes of changing the internal pH value of the sea cucumbers and lowering the activity of the autolytic enzymes of body walls and intestinal tracts of the sea cucumbers are achieved through the ultrasonic-assisted sub-acidic electrolyzed water treatment. The method has the advantages that the sterilization effect is remarkable, the dissolving-out quantity of TCA-soluble oligopeptide, total sugar and reducing sugar is low, and the enzyme activity survival rate of the autolytic enzymes is lower than 15%.

The invention belongs to the technical field of drug preparation, in particular to drug-cyclodextrin nanoparticles and a preparation method thereof. The drug-cyclodextrin nanoparticle system comprises a drug, cyclodextrin and one or more grinding additives. The manufacturing process is as follows: driving a grinding medium to fully mix and grind the materials under the action of external force; and producing a drug-cyclodextrin inclusion compound and simultaneously greatly reducing the particle size of the drug from the usual micron range to the nanometer range. The method integrates cyclodextrin inclusion and the nano-manufacturing technology into a whole and is the first creation at home and abroad on the modern pharmaceutical preparation technology. Starting from the production and manufacturing point of view, the drug-cyclodextrin nanoparticles have the characteristics of high efficiency, safety and reasonable cost, and are applicable to large-scale production. An oral preparation prepared by the method can be used for significantly improving the dissolution rate and the bioavailability of the water-insoluble drug.

A method for preparing and regulating fluorescent carbon nano-dots with high color quality relates to the field of luminescent nano-materials. Dissolve diamine compounds and phenolic compounds in solvent A for mixing, put them into a reaction kettle, and control the temperature at 100-300°C for solvothermal reaction for 2-48 hours; obtain fluorescent carbon nano point, and then purify. Fluorescent carbon nanodots with high color quality can be obtained, the CIE chromaticity coordinates are (0.33,0.33), the CRI value is as high as 93, the CCT is 5453K, the standard white light emission, and the fluorescence spectrum range is within the coverage of 380-700nm. The degree of matching with the standard sunlight spectrum can reach 85%‑114%.

The invention discloses a portable photothermal seawater desalination hollow fiber membrane, a preparation method, a device and an application. The preparation method includes step 1): dispersing and dissolving hydrophilic polymers and nanoparticles in a buffer solution with a pH of 8.5 It is configured as a homogeneous solution in which the ratio of hydrophilic polymer:nanoparticles is 1-20:0-20, and the hollow fiber membrane is flushed with the homogeneous solution for 1-24 hours, and then cleaned and dried for later use to obtain super-hydrophilic hollow membranes on the inner surface. Fiber membrane; step 2): placing the super-hydrophilic hollow fiber membrane on the inner surface obtained in step 1) in an atmosphere of 0.1 to 20 wt% photothermal modification material solution through surface adsorption, surface vapor deposition, surface crosslinking, Suction filtration and / or coating modification are treated for 1-24 hours to prepare a hollow fiber membrane with super-hydrophilic inner surface and photothermal function on the outer surface. The present invention selects a three-dimensional hollow fiber membrane as a base material, and the photothermal seawater desalination hollow fiber membrane obtained through inner / outer surface modification can realize photothermal seawater desalination.

The invention discloses a processing method for mother liquor wastewater generated in one-time nitrifying and refining of disperse blue 56. The method comprises the following steps: (1) complexing and extracting: adjusting the mixed system of the wastewater and an extracting agent to acidity, complexing and extracting, and separating to obtain a water phase I and an oil phase I; (2) adsorbing: carrying out two-stage adsorbing and filtering on the water phase I to obtain a filtrate:(a) carrying out first-stage adsorbing by an adsorbent; (b) carrying out second-stage adsorbing by resin; (3) electro-dialyzing: electro-dialyzing the filtrate to obtain concentrated water and fresh water. A treatment process of extracting, adsorbing and concentrating is adopted, the residual organic matters in the wastewater can be gradually and specifically separated, the COD and the chroma in the wastewater can be removed, and a clean sodium salt solution can be obtained after concentrating the wastewater.

The invention discloses a medicament capable of delaying postharvest rot of a Manihot esculenta Crantz tuberous root, and a preparation method and application of the medicament. The medicament is an aqueous solution and comprises abscisic acid, melatonin and chitosan; and in each litre of medicament, the concentration of the abscisic acid is 400-600[mu]M / L, the concentration of the melatonin is 200-400[mu]M / L, and the concentration of the chitosan is 10-30mM / L. The level of active oxygen in the Manihot esculenta Crantz tuberous root dipped in the medicament disclosed by the invention is lowered, the browning and rotting speed of the Manihot esculenta Crantz tuberous root can be delayed, and in addition, the content of the vitamin C and the starch of the Manihot esculenta Crantz tuberous root is not affected. In addition, the method is convenient, practical, efficient and safe and has a good development potential in a storage, transportation and selling process of the Manihot esculentaCrantz tuberous root.

The invention discloses a one-step preparation method for white light-emitting carbon dots, and relates to the field of luminescent nanomaterials. The white light-emitting carbon dots are prepared byusing the following method: in a constant temperature oven, dissolving o-phenylenediamine and catechol at different ratios in an alcohol solvent which includes methanol, ethanol, propyl alcohol, butylalcohol, pentanol and other alcohol, packaging the mixture into a reaction kettle, controlling the temperature of the oven at 140-240 DEG C, and performing a solvothermal reaction for 4-48 hours so as to obtain fluorescent carbon dots with luminescent peaks covering 400-700 nm, wherein the obtained fluorescent carbon dots includes the white light-emitting carbon dots which have CIE chromaticity coordinates of (0.33, 0.33). The white light-emitting carbon dots prepared by using the method has excellent optical properties, a simple preparation method, easily available materials and low cost, and can be directly added to epoxy resin as an encapsulating material of diodes so as to prepare a white light LED device.