67results about How to "Promote green and sustainable development" patented technology

The invention relates to a detection method for the quality of an electric power pipe gallery reinforcing steel bar mesh based on machine vision and a detection device. The detection method comprises the steps of reinforcing steel bar quantity detection, reinforcing steel bar spacing detection and reinforcing steel bar diameter detection, and is characterized in that reinforcing steel bar quantity detection adopts technologies such as image stitching and Hough transform straight line detection to count the quantity of reinforcing steel bars within a meter marker and judges whether the reinforcing steel bars are qualified or not; reinforcing steel bar spacing detection adopts an edge extraction technology, fits each reinforcing steel bar by using a least square method, calculates the distance between adjacent reinforcing steel bars in a rectangular detection area and judges whether the reinforcing steel bar spacing of the section is qualified or not; and reinforcing steel bar diameter detection is similar to reinforcing steel bar spacing detection, the difference lies in that double edges of each reinforcing steel bar are fit by using the least square method in the rectangular detection area, and the diameter of each reinforcing steel bar is calculated so as to judge whether the reinforcing steel bar diameter of the section is qualified or not. The detection device comprises a scalable triangular frame, a double-pipe guide rail, a stepper motor, a level gauge and a cradle head loaded with an ultra high definition camera. According to the invention, information of the reinforcing steel bar mesh of a project under construction can be collected in advance before reinforced concrete is poured.

The invention discloses a preparation method of a gangue base mine cemented filling material, and belongs to the field of mine filling materials. Cementing activity hidden in gangue is stimulated in a compound stimulation way, cement is partially replaced with the cementing activity to serve as a cementing material for cemented filling mining, and then the material is mixed with fine particle size gangue to be prepared into the mine cemented filling material. The process for preparing the mine cemented filling material is simple, large proportion dosage of gangue powder and cement is realized, the filling material has excellent mechanical property and stable conveying property, no segregation or no bleeding exists, the application of gangue in mine filling is broadened, the mine filling cost is reduced, the material conveying property is improved, at the same time, the purpose of effective use of gangue is realized, and mine filling is promoted to develop forward.

The invention belongs to the field of coal chemical industry and provides a method for producing ethylene by utilizing pulverized coal. The method comprises the steps of (1) pyrolysis upgrading, (2) pressure swing adsorption and hydrogen extraction, (3) smelting production of calcium carbide, (4) CO conversion decarburization and hydrogen production, (5) acetylene generation, (6) acetylene hydrogenation reaction and (7) cryogenic separation so as to obtain the ethylene and other hydrocarbon products. According to the method, high-quality resources such as blocky coke, semi-coke and anthracite which are high in price are replaced with medium-low-order raw pulverized coal which is low in price, the medium-low-order raw pulverized coal serves as a raw material for producing the calcium carbide, the process energy consumption is low, high value-added tar and pyrolysis gas byproducts are obtained in the pyrolysis process, and the overall economy of the process is improved; a pyrolyzed solid product adopts a hot delivery process, the sensible heat is fully utilized, and the power consumption of a calcium carbide furnace is reduced; hydrogen obtained by the pressure swing adsorption of a pyrolysis gas product and hydrogen obtained by the tail gas conversion of the calcium carbide furnace are used for the acetylene hydrogenation reaction, another product of the calcium carbide furnace reacts with CO2 to generate nano calcium carbonate, and the environmental pollution is reduced.

The invention provides a device and method for producing ethylene through hydrogenation of high concentration acetylene. The device comprises an acetylene hydrogenation reactor, a solvent absorbing tower, and an ethylene condensing device. The structure of the device is simple. An acetylene feed pipeline is connected to the acetylene hydrogenation reactor through an acetylene solvent tank; acetylene is dissolved into a solvent and then introduced into the acetylene hydrogenation reactor; through liquid phase pressurization, the pressure limitation of acetylene is overcome, thus hydrogenation of acetylene can be carried out under a pressure of 1.5 MPaG or more; the acetylene hydrogenation reactor is connected to the solvent absorbing tower, after the acetylene hydrogenation, the obtained gas phase is absorbed by the solvent, the multi-tower rectification separation in the conventional technology is not needed therefore, and the energy consumption is low. The provided device and method can utilize the excess calcium carbide product, greatly relieves the demand on ethylene in our country, and has an important meaning for the sustainable development of acetylene industry of our country, energy saving, and emission reduction.

The invention relates to a process and a system of preparing calcium carbide and ethylene through oxygen / coal injection, wherein the process includes following steps: (1) preparation of calcium carbide; (2) CO conversion and decarburization and hydrogen production; (3) acetylene generation; (4) acetylene hydrogenation reaction; and (5) cryogenic separation. In the invention, oxygen and coal powder are injected during a calcium carbide smelting process. Because that heat generated from incomplete combustion of oxygen and coal can radiate to a position which is difficult to reach by arc light, the process, compared with a conventional calcium carbide furnace method, is more uniform in heat distribution in furnace, thereby reducing electric consumption in the calcium carbide furnace and calcium carbide production period. The injected coal powder can replace a part of coke, so that the process can reduce production cost of the calcium carbide. Meanwhile, the process fully utilizes calcium carbide smelting tail gas being rich in CO, which is used for preparing hydrogen through the CO conversion to prepare the hydrogen source in the acetylene hydrogenation reaction, so that not only is environment pollution reduced but also economic benefit is improved greatly.

The invention discloses a sulfate aluminate cement based 3D printing material and a preparation method thereof. The 3D printing material comprises following raw materials in percentage by weight: 45 to 50% of sulfate aluminate cement; 45 to 50% of fine aggregate; 0 to 1% of a water reducer; 0 to 0.08% of a retarder; 0 to 0.2% of cellulose ether; 0.5 to 2% of redispersible latex powder; 0.001 to 0.002% of an antifoaming agent; and 0.1% to 0.3% of fibers; wherein the total percentage by weight of all raw materials is not greater than 100%. The provided 3D printing material has an excellent rheological property and self-curing performance; is matched with a 3D printing technology at the same time, has excellent mechanical properties on the premise that the weight of the 3D printing material is reduced, when being taken as a wall material, and can be used to construct composite structures of buildings.

The invention discloses a high-performance on-line quenching high-strength steel pipe and a production method thereof, and belongs to the field of high-strength steel pipe production. The high-performance on-line quenching high-strength steel pipe is prepared from the following chemical components in percentage by mass: 0.1-0.3% of C, 0.1-0.8% of Si, 0.4-2.0% of Mn, 0.001-0.015% of P, 0.001-0.015% of S, 0.001-0.05% of Al, 0.005-0.05% of Ti, 0.001-0.01% of O, 0.003-0.012% of N, 0.0005-0.005% of B, 0.001-0.01% of Ca and Mg, 0.002-0.012% of B, Ca and Mg, and the balance of Fe and inevitable impurities. The high-performance on-line quenching high-strength steel pipe gets rid of a conventional off-line heat treatment means; the effective effect of inclusions in smelted steel is fully utilized; a martensite and / or bainite structure is obtained in cooperation with an on-line quenching process; the performance is improved; meanwhile, the production efficiency is improved; and low-cost green production of the high-strength steel pipe is achieved.

The invention relates to a carbon-based lithium ion battery negative electrode material taking sludge as a precursor and preparation of the carbon-based lithium ion battery negative electrode material. During preparation, the sludge is carbonized and processed in advance, and the carbon-based lithium ion battery negative electrode material is obtained by sequentially performing washing and drying after pickling and alkali activation. Compared with the prior art, the carbon-based lithium ion battery negative electrode material has the advantages of greenness, environmental friendliness, simple preparation process and low production cost, the resource utilization of the sludge can be achieved, and the prepared carbon-based lithium ion battery negative electrode material is high in specific area and specific capacity and good in cycle property and has wide application prospect.

The invention relates to anti-seepage iron tailings concrete and a preparation method thereof. The concrete is prepared by replacing an ordinary concrete coarse aggregate with iron tailings balls, replacing a fine aggregate with iron tailings powder and adding an admixture, water and a water reducing agent. The concrete comprises the following components in percentage by mass: cement 14% to 17%, iron tailings ball 42% to 52%, iron tailings powder 28% to 34%, water reducing agent 0.14% to 0.17 %, admixture 0.28% to 0.34%, and water 5.2% to 6.3%. The admixture comprises the following componentsin percentage by mass: calcium oxide 20% to 40%, calcium chloride 20% to 40% , and sodium nitrate 30% to 50%. According to the invention, the concrete aggregate is replaced with iron tailings completely, that is, the replacement rate reaches 100%, thereby greatly improving the recovery and utilization ratio of the iron tailings, and turning the iron tailings, which is waste, into treasure. The added admixture effectively improves the gas permeation resistance and the chloride ion permeation resistance of the tailings concrete.

The invention relates to a method and system for preparing ethylene from the raw material of powdered coal. The method includes the steps of pyrolysis upgrading and smelting production of calcium carbide, pressure-swing adsorption hydrogen extraction, CO conversion, decarburization hydrogen production, acetylene generation, acetylene hydrogenation reaction and cryogenic separation. The method has the advantages that technical energy consumption is lowered, hydrogen sources are broadened and by-products are recycled, environmental pollution is easily reduced, the ethylene production cost is lowered, the economic benefits are greatly increased, and the method can be better applied to large-scale industrial production.

The invention provides a method for rapidly detecting benzotriazole ultraviolet absorbents in textiles. The method comprises the following steps of: (1) crushing a sample to be detected into fragmentswith the particle size of less than 0.5 mm in a physical mode, uniformly mixing the fragments to be used as a test sample, weighing a proper amount of the test sample, and placing the test sample atthe bottom part of a sample cup of a thermal cracker; (2) putting a proper amount of silanized glass wool into the sample cup of of the thermal cracker, then putting the sample cup of the thermal cracker into thermal cracking equipment, and carrying out thermal cracking-gas chromatography-mass spectrometry analysis; and (3) comparing the retention time and a peak area of each benzotriazole ultraviolet absorbent in the sample to be detected and the standard sample, and carrying out qualitative and / or semi-quantitative detection. The method can accurately and efficiently detect whether the textile contains four benzotriazole ultraviolet absorbents at the same time, the sample does not need chemical solvent extraction, the detection period is shortened to the maximum extent, the sample weighing amount is small, and the sensitivity of the method is high.

The invention discloses an electrocatalytic acetylene hydrogenation reaction method. The method comprises the following steps of: injection of raw material gas: introducing acetylene-containing raw material gas into an acetylene gas chamber separated from an electrochemical device through a working electrode; and electro-catalytic acetylene hydrogenation reaction: switching on a power supply to enable the electrochemical device to work to carry out electrolytic reaction, so as to enable the acetylene-containing gas diffused to the working electrode to be subjected to electro-catalytic acetylene hydrogenation reaction and reduce acetylene into ethylene. According to the invention, acetylene can be electrocatalytically converted into ethylene at high activity, high conversion rate and high selectivity at a low temperature, basic conditions can be created for large-scale application of electrocatalytic acetylene hydrogenation, the method is expected to replace the existing thermocatalytic acetylene hydrogenation chemical process, and green sustainable development of polyethylene industrial production is promoted.

The invention relates to an anti-compression and anti-permeation iron tailing concrete and a preparation method thereof. According to the concrete, iron tailing balls replace coarse aggregate of ordinary concrete, iron tailing powder replaces fine aggregate, and an admixture, water and a water reducing agent are blended for preparation, wherein the mass percentages of above components are as follows: 14-17% of cement, 42-52% of iron tailing balls, 28-34% of iron tailing powder, 0.14-0.17% of the water reducing agent, 0.28-0.34% of the admixture, and 5.2% -6.3% of water. Compared with concretemade from other tailings, the iron tailing concrete is characterized in that iron tailings are used for replacing all concrete aggregate, the replacement rate reaches 100%, the recycling rate of the iron tailings is greatly improved, and waste is turned into treasures. The cubic compressive strength of the tailing concrete is effectively improved after the admixture is added, and the anti-air-permeation performance and the anti-chloride-ion- permeation performance are improved.

The invention provides a subway open cut section prefabricated box culvert overlapping structure and a construction method thereof, and relates to the field of rail transit construction. The subway open cut section prefabricated box culvert overlapping structure comprises a box culvert and precast piles distributed on the two sides of the box culvert, first anchor bars are arranged in first preformed grooves in the side faces of the precast piles, and second anchor bars are arranged in second preformed grooves in the side faces of the box culvert; and the first anchor bars extend into the second preformed grooves to be connected with box culvert structural bars, and the second anchor bars extend into the first preformed grooves to be connected with precast pile structural bars. The subwayopen cut section prefabricated box culvert overlapping structure has the advantages that factory prefabrication is conducted on an enclosure structure and a section main body structure, and after enclosure work is completed, the temporary enclosure structure can serve as a permanent structure to be combined with the box culvert; and the enclosure structure is fixedly connected with opposite side structural bars through the reserved anchor bar structure, permanent and temporary overlapping of a prefabricated square pile enclosure and a section main body is achieved, the supporting strength is met, meanwhile, the thickness of the side wall of the box culvert main body structure can be reduced, and the construction speed is increased.

The invention provides a preparation method of a lignin-based water-retention double-layer sustained and controlled release fertilizer. The preparation method comprises the following steps: (1) blending polyvinyl alcohol and a cellulose derivative to obtain a mixed liquid for later use; (2) carrying out graft polymerization on an acrylic acid-acrylamide copolymer and a lignin derivative to obtain a lignin-based water absorbent; (3) uniformly spraying the blended solution in the step (1) on the surfaces of fertilizer particles, and repeatedly coating multiple times to obtain a single-layer coated fertilizer; and (4) uniformly coating the lignin-based water absorbent powder which is ground in advance on the outer layer of the single-layer coated fertilizer, and finally drying the fertilizer at 55 DEG C to obtain the double-layer coated slow-release fertilizer. According to the invention, the coating materials used in the invention are all degradable materials, and a double-layer coating form is adopted, so that the defects of single performance and difficulty in control of a single-layer coating can be overcome; and the method is simple in process, low in cost, short in technological process period and free of waste.

The invention provides a rapid detection method for permethrin in anti-mosquito fabric, and the method comprises the following steps: (1) crushing a sample to be detected into fragments or powder with the particle size of 0.5 mm or less, uniformly mixing, weighing a proper amount of the mixed sample, putting the mixed sample at the bottom of a thermal cracking sample cup, and putting a proper amount of silanized glass wool into the thermal cracking sample cup; (2) preparing a standard product of permethrin; (3) respectively putting the thermal cracking sample cup in the step (1) and the standard substance in the step (2) into thermal cracking equipment, and carrying out thermal cracking-gas chromatography-tandem mass spectrometry analysis; and (4) carrying out qualitative and quantitative detection according to the retention time and peak area comparison of the permethrin in the to-be-detected sample and the standard substance. The method can accurately and efficiently detect whether the textile contains permethrin or not, the sample does not need to be extracted by a chemical solvent, the detection period is shortened to the maximum extent, and the method is environmentally friendly, healthy, small in sample weighing amount, low in detection limit and high in sensitivity.

The invention relates to the fields of food and food processing, and particularly to soybean meal dried tofu and a preparation method thereof. The soybean meal dried tofu is prepared by taking soybeanprotein, soybean meal, vegetable oil, cassava modified starch, glutinous rice flour, glutamine transaminase, edible gypsum and water as raw materials and through the processes of marinating syrup preparation, hydration, emulsification, mixing, out of the pan, reacting, slicing, marinating, drying, material mixing, packaging, sterilizing and the like. The soybean meal dried tofu product maintainsthe elasticity, toughness, hardness and unique taste of the traditional dried tofu, also contains rich nutrition and low fat content, and is beneficial to the health of eaters. At the same time, the production process of the soybean meal dried tofu is simple in operation, basically has no sewage discharge, cannot cause harmful effect on surroundings, and is beneficial to the green and sustainabledevelopment of food enterprises.

The invention relates to a constructing method of a fry cultivation pond based on a geomembrane, and belongs to the technical field of aquaculture. The method comprises the following steps of 1, geomembrane paving; 2, commercial fish breeding; 3, pond cleaning and bait biological cultivation; 4, fry cultivation; 5, recycling of a geomembrane pond. The geomembrane is utilized to accumulate organic fertilizer like residual baits and metabolite generated in the commercial fish breeding process, the water is cultivated, by replying on ecological cycle of the pond itself, reproduction of natural biological baits is promoted, the biological bait problem in the fry cultivation process is solved, the fry survival rate is increased, the economic cost is effectively lowered, and the constructing method has the advantages of saving time and labor, being high in success rate and the like, and the ecological and economic benefit is obvious.

The invention provides a rail transit engineering shallow-buried interval prefabricated laminated structure and a construction method thereof, and relates to the field of rail transit construction. The rail transit engineering shallow-buried interval prefabricated laminated structure comprises a box culvert and prefabricated piles distributed on the two sides of the box culvert, and first longitudinal ribs inside the prefabricated piles and second longitudinal ribs in the box culvert are jointly matched with cylindrical spiral linear connecting ribs; and in the spiral structures of the connecting ribs, first transverse ribs distributed perpendicular to the first longitudinal ribs are arranged on the sides, away from the second longitudinal ribs, of the first longitudinal ribs, and second transverse ribs distributed perpendicular to the second longitudinal ribs are arranged on the sides, away from the first longitudinal ribs, of the second longitudinal ribs. The enclosure structure andinterval main body structure are prefabricated in an industrialized mode, the temporary enclosure structure can serve as a permanent structure to be combined with the box culvert after enclosure workis completed, permanent and temporary overlapping of the prefabricated square pile enclosure and the interval main body is achieved, the side wall thickness of the box culvert main body structure canbe reduced while the supporting strength is met, and the construction speed is increased.

The invention discloses a supplemental ditch planting method of vegetables, and aims at increasing the fertilizer utilization rate and making root systems of the vegetables developed. The method comprises the steps that when land preparation is conducted, base fertilizer is not applied, and after land is subjected to rotary tillage, field planting ditches are dug according to the planting spacingof the vegetables; fertilization is measured according to the size of the ditch bottoms of the field planting ditches, 3-5 square decomposed cow manure or 2-3 square decomposed chicken manure and 50-55 kg of phosphorus diamine are uniformly stirred and uniformly sprayed into the bottoms of the field planting ditches, and are fully and uniformly stirred with soil; supplemental ditches are dug at the portion 2 / 3 away from the sides of the field planting ditches, wherein the ditch bottoms of the supplemental ditches is 1 / 3 higher than the bottoms of the field planting ditches; before field planting, the field planting ditches are watered with sufficient water, the water depth exceeds 2 / 3 of the depth of the field planting ditches, so that the field planting ditches and the supplemental ditches are all filled with water; after water permeates thoroughly, seedling strip matrix lumps are completely pulled out of plugs, and are pressed in bottom sludge of the supplemental ditches according tothe plant spacing required by vegetable field planting, so that the peripheries of the matrix lumps are in close contact with soil, and the upper surfaces of the matrix lumps are slightly lower thanthe bottoms of the supplemental ditches.

The invention discloses an environment-friendly and low-carbon calcium carbide synthesis process. In the process, limestone and calcite are directly used as a calcium source for synthesizing calcium carbide; limestone calcining and calcium carbide synthesis processes are coupled in one reaction furnace, so that a process of calcining the limestone in a lime kiln in the conventional calcium carbideproduction process is eliminated; meanwhile, in the process, CO2 and CaO which are generated by decomposing CaCO3 can further respectively serve as a gasifying agent and a catalyst for carbon, and part of the generated CO2 is locally converted into CO in real time; the high-temperature CO gas generated in a high-temperature region exchanges heat with the medium temperature section and a high-temperature carbon removal process in sequence, thus realizing recycling of waste heat of high-temperature exhaust gas and improving the overall heat efficiency; gas in a medium temperature stage reacts with a high-temperature solid phase product, so that apparent heat of gas and solid phase materials is recycled, and CO2 in the gas and non-reacted carbon in the high-temperature solid phase product are converted into a high-additional-value product CO.

The invention discloses a preparation method of a gangue base mine cemented filling material, and belongs to the field of mine filling materials. Cementing activity hidden in gangue is stimulated in a compound stimulation way, cement is partially replaced with the cementing activity to serve as a cementing material for cemented filling mining, and then the material is mixed with fine particle size gangue to be prepared into the mine cemented filling material. The process for preparing the mine cemented filling material is simple, large proportion dosage of gangue powder and cement is realized, the filling material has excellent mechanical property and stable conveying property, no segregation or no bleeding exists, the application of gangue in mine filling is broadened, the mine filling cost is reduced, the material conveying property is improved, at the same time, the purpose of effective use of gangue is realized, and mine filling is promoted to develop forward.

The invention discloses a compound feed for increasing the laying rate of breeding geese. The compound feed comprises the following components in parts by weight: 20-45 parts of corn, 15-30 parts of soybean meal, 18-40 parts of sophora japonica leaf powder, 15-25 parts of tapioca flour, 2-8 parts of eggshell powder, 0.6-1.2 parts of sodium chloride, 0.02-0.08 part of allicin and 2 parts of a premix special for the breeding geese in an egg laying period. The compound feed disclosed by the invention can effectively solve a series of problems of low egg laying rate, light egg weight and the likein the production of the breeding geese, can effectively improve the egg laying rate of the geese, and is good in hatching egg quality, so that the egg yield and the breeding benefit of the breeding geese are improved.

The invention discloses a crop rotation method of corns and no-tillage rape. The method comprises the following steps: (1) carrying out rotary tillage on a field block after rape is harvested; (2) carrying out seeding of the corns; (3) carrying our field management until the corns are harvested; (4) carrying out no-tillage direct seeding of the rape after the corns are harvested, wherein the seeding time is October 10 to October 25 every year; (5) carry out field management until the rape is harvested; (6) repeating steps (1) to (5) so as to realize the crop rotation of the corns and the no-tillage rape. The rape can be harvested according to the different functions on the basis of growth vigor and market demands; the harvesting way of the corns is determined according to the seeding timeand the market demands; the silage corns can meet the demand of the animal husbandry for high-quality feed; the grain harvesting time can be prolonged to the upright dehydration time after physiological maturity, so that the mechanical harvesting quality of grains is improved, and the mechanized operation of the middle and lower reaches of the Yangtze River is realized all the year round; furthermore, a paddy field is changed into a dry field, so that greenhouse gas emissions and chemical fertilizer pollution are also reduced, and the sustainable green development of agriculture is promoted.

The invention belongs to the technical field of environmental assessment, and discloses an airport parking position priority analysis method and system aiming at the atmospheric environment influence.The airport parking position is partitioned for the first time according to the airport parking position distribution rule and the aircraft scene operation rule. Based on the aircraft motion model and the speed limit of the airfield, the taxiing time from different parking positions to the entrance of the take-off and landing runway is estimated. Combined with taxiing time, the emissions from taxiing to different parking positions are calculated. Based on the results of pollutant diffusion, the second partition is carried out. Finally, according to the results of parking space partition and the diffusion concentration of pollutants, through the comprehensive evaluation method, the ranking of the impact degree of each parking space partition on the atmospheric environment is calculated, inorder to give priority guidance to the allocation optimization of parking spaces. The invention can lay a foundation for the parking station allocation facing the atmospheric environment influence, and provides decision support.

The invention discloses a specific primer, a probe and a kit for detecting Chinese soft-shelled turtle flavivirus, and belongs to the technical field of biological detection. According to the specificprimer, the probe and the kit, a pathogenic factor causing the disease is proved to be a virus by collecting a diseased turtle tissue sample and performing pathogen analysis. After a partial sequenceof the virus is obtained by adopting an RACE technology, a primer group, the probe and the kit for specifically detecting the virus are designed in a targeted manner, a method for sensitively, specifically and quickly detecting the Chinese soft-shelled turtle flavivirus is provided, the blank that no Chinese soft-shelled turtle flavivirus detection method exists at present is filled up, and the method is suitable for definite diagnosis, screening and prevention of the Chinese soft-shelled turtle flavivirus. The specific primer, the probe and the kit provide technical support for fry quarantine, provide a tool for cutting off virus transmission from the source, and are beneficial to green sustainable development of the Chinese soft-shelled turtle breeding industry.

The invention relates to the technical field of plant protection, and in particular, relates to a biocontrol strain TMN-1, and a preparation method and an application of a biocontrol microbial inoculum. The biocontrol strain TMN-1 is a hypocrea fungus; preparation of the biocontrol microbial inoculum containing the biocontrol strain TMN-1 comprises the steps: taking rhizosphere soil of healthy tobacco plants in an ill land where bacterial wilt occurs in a tobacco planting area, screening the biocontrol strain TMN-1 on a rose-bengal selective culture medium by a dilution coating plate method, activating the screened biocontrol strain TMN-1 on a PDA culture medium, carrying out shake cultivation on the obtained pure biocontrol strain TMN-1 in a PD culture solution at the speed of 180 rpm and at the temperature of 28 DEG C for 5 d, centrifuging at the speed of 7000 rpm for 8-10 min, and adjusting the spore concentration by sterile water to 1*10<8> cfu / mL. The biocontrol microbial inoculum can promote the healthy growth of tobacco, improve the structure of soil microbial community, have good control effect on tobacco bacterial wilt and reduce the harm of tobacco bacterial wilt when being applied in tobacco planting.

A preparation method of a lignin-based water-retaining double-layer slow-release fertilizer, step (1) blending polyvinyl alcohol and cellulose derivatives to obtain a mixed liquid for use; step (2) blending acrylic acid-acrylamide copolymer and lignin Derivatives are grafted and polymerized to obtain a lignin-based water-absorbing agent; step (3) spray the blended solution in step (1) evenly on the surface of the fertilizer granules, and obtain a single-layer coated fertilizer after repeated coating; step ( 4) Evenly coat the pre-ground lignin-based water-absorbing agent powder on the outer layer of the single-layer coated fertilizer, and finally dry the fertilizer at 55°C to obtain a double-layer coated slow-release fertilizer. The coverings used in the present invention are all degradable materials, and adopt the form of double-layer coating, which can make up for the shortcomings of single-layer coating with single performance and difficult control. The invention has simple process, low cost, short process period and no waste.