37results about How to "Solve the problem of low quality" patented technology

This invention relates to a mask for screen printing, which includes a mask body composed of a plurality of pattern areas having holes for screen printing and a peripheral area surrounding the outside of the pattern areas; and a protrusion portion formed in the peripheral area of a back surface of the mask body, and to a screen printing method using the same.

The invention relates to a preparation method of an ultraviolet absorbent intermediate etocrilene (ETO). The preparation method comprises the following steps of: 1, adding benzophenone, ethyl cyanoacetate, a catalyst and a water-insoluble solvent into a condensation reaction kettle, carrying out backflow water distribution reaction for 12-15h, and then, cooling to 50-55 DEG C, wherein the excessive equivalent of the ethyl cyanoacetate relative to the benzophenone is 0.2-5; 2, washing the reaction liquid by using water, and separating the liquid to respectively obtain a water layer and an organic layer; distilling the recycled water at the water layer at normal pressure, dissolving distillation tailings by using a solvent same as the solvent used in the step 1, and then, replenishing a proper quantity of catalyst to obtain a product, wherein the distilled recycled water is used in the step 2, and the product is used in the step 1; and distilling the recycled solvent at the organic layer at normal pressure, and carrying out reduced pressure distillation to recycle the excessive ethyl cyanoacetate, wherein the recycled solvent and ethyl cyanoacetate are used in the step 1; 3, carrying out reduced pressure distillation on the distillation tailings, adding 75-100% of ethanol for crystallizing, and filtering to obtain the etocrilene; and 4, filtering a mother solution obtained in the step 3, recycling the ethanol at normal pressure, and carrying out reduced pressure recycle on the benzophenone and the etocrilene, wherein the recycled ethanol is used in the step 3, and the recycled benzophenone and etocrilene are used in the step 1. The preparation method has the advantages of simplicity in operation, short production period, little environment pollution, low energy consumption, realization of material recycling, and the like.

The invention discloses a method for constructing a Small RNA cDNA library. A group of DNA molecules disclosed by the present invention, the group of molecules is composed of four molecules as shown in (1)-(4): (1) the DNA molecule shown in SEQ ID No.1; (2) SEQ ID No. The DNA molecule shown in 2; (3) the DNA molecule shown in SEQ ID No.3; (4) the DNA molecule shown in SEQ ID No.4. The method for rapidly separating Small RNA disclosed by the invention solves the problems of long time, complicated operation, high requirements and high toxicity of the current separation of Small RNA by acrylamide gel electrophoresis. Moreover, the method for constructing a Small RNA cDNA library disclosed in the present invention reduces non-specific products and increases the content of target products, and the method is simpler and faster than traditional methods.

The invention provides a method for preparing homosalate. The method comprises the steps that isophorone serves as raw materials, a hydrogenation reaction is performed under the action of a catalyst, then an epimerization reaction is performed, and 3,3,5-Trimethylcyclohexanol is prepared; a transesterification reaction is performed on the prepared 3,3,5-Trimethylcyclohexanol and methyl salicylate, and finally the homosalate is prepared. The method is easy and convenient to operate, green and environmentally friendly, and the prepared homosalate is high in quality, wherein the cis form content is larger than or equal to 85.0 percent, the trans form content is smaller than or equal to 15 percent, the total content is larger than or equal to 99.0 percent, the single impurity content (GC) is smaller than or equal to 0.1 percent, and the total impurity content (GC) is smaller than or equal to 0.5 percent.

The invention discloses a method for breeding seedlings of grapes by using containers and belongs to the field of fruit tree seedling raising. The method comprises the following steps of: (1) scissoring annual grape branches in winter to conserve in winter; (2) taking out the branches in late February of the next year, cutting the branches into sections of 18 to 20 cm, retaining stalks of 2 to 3 buds, and inserting into containers by cuttage, wherein nutritional soil comprises a mixture of reed residue matrix and garden soil, or a mixture of rich chaff dust and garden soil, or a mixture of the reed residue matrix, the rich chaff dust and the garden soil; and (3) inserting bamboo poles with the length of 1m into the containers to fix young sprouts when nursery stocks have 7 to 8 leaves, and pinching when the young sprouts are 80 cm. The method is not limited by season, so the defects in seedling in big lands are effectively overcome, root systems are formed in the containers and have good and complete root balls, roots are not damaged when seedlings are lifted, the seedlings are not required to be trimmed before planting, one-step forming is realized, time and labor are saved, survival rate is high after transplantation, the slow seedling stage does not exist, growth quantity is large in the initial stage, flower bud differentiation is realized in advance, high yield in early stage is realized, and quality of the nursery stocks is high.

The invention relates to a preparation method of a sun-screening agent OMC (iso-octyl P-Methoxycinnamate). The preparation method comprises the following steps of: 1, adding p-anisaldehyde, malonic acid, a catalyst I organic secondary amine substance, a catalyst II organic acid substance and a water-insoluble organic aromatic hydrocarbon solvent to a condensation reaction kettle, and carrying out reflux water diversion reaction for 4-5 hours; 2, after condensation reaction is finished, cooling to 5-15 DEG C, filtering to obtain a p-methoxycinnamic acid crude product, directly applying filter liquor to next reaction, and optionally supplementing a small quantity of catalysts and solvents to the filter liquor; 3, adding catalyst III macroporous type storng acid cation exchange resin, isooctyl alcohol, the p-methoxycinnamic acid crude product and an aromatic hydrocarbon or aliphatic hydrocarbon solvent to an esterifying reaction kettle, and carrying out reflux water diversion reaction for 2-3 hours; and 4, after esterifying reaction is finished, cooling to 65 DEG C, filtering and recovering the catalysts for mechanical application, washing the filter liquor to neutrality through a 5% sodium carbonate water solution, desolventizing, and rectifying to obtain the final product isooctyl p-methoxycinnamate. The method disclosed by the invention has the characteristics of easiness, convenience, easiness in control, industrial production, low environment pollution, low energy consumption, material recycling, high product purity, and the like.

The invention relates to a process for synthesizing p-tert-butylbenzoic acid. The process comprises the following steps of: adding p-tert-butyltoluene and cobalt acetate into a reaction kettle, introducing oxygen-containing gas, triggering at the temperature of between 150 and 155 DEG C, performing oxidation reaction for 0.5 to 1 hour, and continuously reacting at the temperature of between 135 and 145 DEG C for more than 5 hours to obtain a p-tert-butylbenzoic acid crude product; cooling the p-tert-butylbenzoic acid crude product to crystallize, performing centrifuge dripping, and striking and washing by using p-tert-butyltoluene to obtain a centrifugation crude product; and adding the centrifugation crude product into a dissolution kettle, adding methylbenzene, raising temperature and dissolving, filtering when a mixture is hot to remove impurities, adding water to wash, transferring materials to a recrystallization kettle, cooling to crystallize, centrifuging, striking and washing by using methylbenzene, and drying to obtain a p-tert-butylbenzoic acid finished product. The prepared p-tert-butylbenzoic acid is white crystals and does not contain mechanical impurities; and the melting point is 164.0 to 167.0 DEG C, the acid value is 312 to 316mgKOH / g, high performance liquid chromatography (HPLC) purity is more than or equal to 99.2 percent, moisture is less than or equal to 0.08 percent, and methylbenzene is less than or equal to 0.05 percent.

The invention discloses a technology for producing iron fine powder through a red mud fluidized bed method, and belongs to the technical field of steel production. The technology is characterized by comprising the following steps that red mud grout is diluted and screened, and rough iron powder is obtained through a pretreatment manner of gravity sorting, magnetic sorting or gravity sorting and magnetic sorting combination; drying is conducted; the fluidization reducing reaction temperature of a reducing fluidized bed is controlled to range from 450 DEG C to 550 DEG C, gas with the volume ratio of CO+H2 being 40%-50% is used in the reducing fluidized bed to conduct the reducing reaction on the rough iron powder, the reducing reaction time is controlled to range from 8 min to 15 min, and reduced magnetized rough iron powder is obtained; and the reduced magnetized rough iron powder is ground to be smaller than 100 meshes, then, physical separation is conducted, and the iron fine powder with the grade being 61% or above is obtained. The technology can overcome the defect that during physical method red mud iron separating, the iron powder product quality is low, and energy consumptionduring chemical method red mud iron separating can be greatly reduced.

The invention relates to a preparation method of lilial. The preparation method of lilial comprises the following steps that p-tert.-butyl-benzaldehyde, methanol and caustic soda flake solutions having different concentrations are added into a reactor; n-propanal is dropwisely added into the reactor at a certain temperature and undergoes a condensation reaction and after addition of n-propanal isfinished, the condensation reaction lasts for 0.5 to 2 hours under the condition of heat preservation; acidic materials are added into the reaction system to adjust a pH value and to stop the condensation reaction; after the condensation reaction is finished, methanol is recovered by distillation and a condensation product p-tert.-butyl-alpha-methyl phenyl acrolein is obtained by film evaporator distillation; methanol, p-tert.-butyl-alpha-methyl phenyl acrolein and a hydrogenation catalyst are added into a hydrogenation reactor; hydrogen is fed into the hydrogenation reactor and the mixture in the hydrogenation reactor undergoes a hydrogen reaction; and after the hydrogen reaction is finished, the reaction products are subjected to filter pressing, solvent removal and rectification so that a finished product lilial is obtained. Lilial obtained by the preparation method is a colorless and transparent liquid, and has a refractive index (nd20) of 1.504 to 1.506, the specific gravity (25 DEG C, mg / mL) of 0.942 to 0.946, an acid value (mgKOH / g) of 2.0(max.), the GC content (determined by an area normalization method) of m-LLY less than 2.0%, p-LLY great than or equal to 97.0% and m-LLY+p-LLY great than or equal to 98.0%, and the moisture content less than or equal to 0.25%.

The invention relates to a tridemorph synthesis process which includes the steps: adding tridecyl alcohol and optional solvents into a reaction kettle, adding a catalyst, stirring and mixing mixture,leading into hydrogen, and heating the reaction kettle; adding 2, 6-thebaine when the temperature of the reaction kettle reaches the temperature of 200 DEG C or more, and maintaining the reaction kettle to perform reaction in a certain pressure and at a certain temperature until reaction is completed; post-processing a reactant to obtain a reactant finished product. According to the tridemorph synthesis process, the tridemorph with the purity larger than 99% is acquired under the conditions of high selectivity and high yield, and waste water, waste gas and industrial residues are greatly reduced.

The invention discloses a low-temperature and low-humidity driven double-rotating-wheel dehumidification air conditioning system and an air supply method thereof. The low-temperature and low-humiditydriven double-rotating-wheel dehumidification air conditioning system comprises a double-rotating-wheel dehumidification air conditioning unit, a hot water circulating system, a cold water circulatingsystem and a sensible heat air conditioning terminal device. The double-rotating-wheel dehumidification air conditioning unit comprises a first dehumidification rotating wheel, a second dehumidification rotating wheel, a plate-type heat recovery device, an air pre-cooler, an air recooler, a main air heater, an auxiliary air heater, a treatment fan and a regeneration fan. The hot water circulatingsystem comprises a low-grade energy heat collector. The cold water circulating system comprises a water return well and further comprises a water supply well, a reservoir and a water quality treatment device which are sequentially connected. The air supply method of the low-temperature and low-humidity driven double-rotating-wheel dehumidification air conditioning system comprises an air supplying method under the summer working condition and an air supplying method under the winter working condition. The low-temperature and low-humidity driven double-rotating-wheel dehumidification air conditioning system is novel and reasonable in design, low in cost, low in energy consumption, high in refrigerating and heating efficiency, free of greenhouse effect, high in practicability and high in application and popularization value.