1896 results about "Re crystallization" patented technology

Modified release oil in water emulsions that delivers drugs to a target tissue. The emulsions according to the present invention contain the lipophilic active ingredient completely dissolved into the hydrophobic internal phase stabilised by a polymeric surfactant. The presence of this polymer around the hydrophobic droplets avoids the migration of the active ingredient into the external hydrophilic phase and, consequently, its re-crystallization.

The invention provides a method for preparing alpha semi-hydrated gypsum by utilizing desulfurized gypsum, comprising the technological steps of purification, crystal transforming reaction, oriented crystallization, washing and separation, and drying and pulverization. The method concretely comprises the following steps of: enhancing the taste of calcium sulfate dlhy in the desulfurized gypsum to be greater than 95% through a purification treatment; dissolving and recrystallizing the desulfurized gypsum at 70 to 98 DEG C under the normal pressure through adding prepared habit modifiers, transforming into the alpha semi-hydrated gypsum and then carrying out oriented crystallization on the alpha semi-hydrated gypsum to form a short column-shaped alpha semi-hydrated gypsum crystal under the function of an oriented crystal type stabilizer, wherein the length-diameter ratio of the short column-shaped alpha semi-hydrated gypsum crystal is less than 1:3, the 2h breaking strength is greater than 6.5 MPa, the compression strength is greater than 23 MPa, the dry breaking strength is greater than 25 MPa, and the dry compression strength is greater than 53 MPa. The method can be widely used in the fields of ceramics, automobiles, precise casting, heterogenic casting and the like.

The invention provides a packaging shape-stabilizing method of an inorganic hydrated salt phase-change heat storage material, which comprises the following steps: (1) adding a nucleator and deionized water into the inorganic hydrated salt phase-change material, and heating until the inorganic hydrated salt phase-change material achieves the molten state; (2) adding a porous propping material into the molten-state inorganic hydrated salt phase-change material, and stirring sufficiently and uniformly; (3) putting the molten-state mixture obtained in the step (2) in a vacuum environment to enhance the adsorptivity of the porous propping material for the inorganic hydrated salt phase-change material; and (4) moving the molten-state mixture out of the vacuum environment, and immediately putting the molten-state mixture into a low-temperature environment suitable for crystallization to perform recrystallization. The composite shape-stabilized phase-change material obtained by the method has the advantages of stable structure, high latent heat, no toxicity, simple preparation process, short time consumption and low cost.

The invention relates to a process for manufacturing the molybdenum based rare earth alloy plate and equipment for manufacturing the same, wherein pure molybdenum powder is simultaneously added with four rare earth oxides of ZrO2, Y2O3, La2O3 and Nd2O3 according to certain ratio, by utilizing the chrematistics of long and large crystal grain and strong sag resistance and anti-creep property of rare earth alloy elements and the dispersion strengthening function, the re-crystallization temperature of the metal molybdenum is increased, the mechanical performances of the molybdenum based material such as tensile property, yielding behavior and extensibility are improved, and the application range of the molybdenum based material is widened; and the manufacturing process comprises production procedures of material preparation treatment, mixing treatment, forming treatment, sintering treatment, material making treatment and the like and the setting of various technical parameters of special technical equipment and process. With the preparation process, the molybdenum based rare earth alloy plate which has the advantages of good electric conductivity and heat conductivity, excellent high-temperature resistance and corrosion resistance and better mechanical performances such as tensile property, yielding behavior and extensibility, and fills in domestic blank and can replace the imported material can be manufactured.

A semiconductor device having a silicon-on-insulator (SOI) structure includes a field-effect transistor having amorphized source and drain regions formed by implanting silicon or germanium ions into a silicon layer formed over a buried insulator. The fully amorphized source and drain regions ultimately result in permanent crystalline defects that cause p-n junction leakage which allows charge in the body of the device to dissipate, thereby improving the overall efficiency and performance of the device. The source and drain regions are amorphized throughout their entire thickness to prevent single crystal re-crystallization from occurring during annealing and other subsequent processing steps that can degrade the quality of the p-n leakage junctions.

A method for manufacturing a semiconductor thin film is provided which can form its crystal grains having a uniform direction of crystal growth and being large in size and a manufacturing equipment using the above method, and a method for manufacturing a thin film transistor. In the above method, by applying an energy beam partially intercepted by a light-shielding element, melt and re-crystallization occur with a light-shielded region as a starting point. The irradiation of the beam gives energy to the light-shielded region of the silicon thin film so that melt and re-crystallization occur with the light-shielded region as the starting point and so that a local temperature gradient in the light-shielded region is made to be 1200° C./μm or more. In the manufacturing method, a resolution of an optical system used to apply the energy beam is preferably 4 μm or less.

A novel process is provided for producing pramipexole base or its optical isomeric mixture as defined hereinabove i.e. (R,S)-2-amino-6-propyl-4,5,6,7-tetrahydrobenzothiazole avoiding the use of borane tetrahydrofuran complex and using a more convenient reducing agent like sodium triacetoxyborohydride instead. The provided process comprises reacting the starting material (S)-2,6-diamino-4,5,6,7-tetrahydrobenzothiazole or its optical isomeric mixture as defined hereinabove i.e. (R,S)-2,6-diamino-4,5,6,7-tetrahydrobenzothiazole with propionaldehyde in an organic solvent to obtain the respective enamine, which is subsequently reduced in situ, optionally without isolation, to obtain pramipexole or its optical isomeric mixture as defined hereinabove i.e. (R,S)-2-amino-6-propyl-4,5,6,7-tetrahydrobenzothiazole, and the acid addition salts thereof. The present invention also provides a process for purifying pramipexole dihydrochloride or the dihydrochloride salt of its optical isomeric mixture as defined hereinabove i.e. (R,S)-2-amino-6-propyl-4,5,6,7-tetrahydrobenzothiazole dihydrochloride by re-crystallization from a suitable solvent.

The invention provides a production system and method of low-yield-ratio hot-rolled high-strength anti-seismic reinforcing steel bars. The method includes the steps that a heating furnace, a rough rolling unit, a pair of truncate scissors, an intermediate rolling unit, a post-intermediate-rolling water cooling device, another pair of truncate scissors, a finish rolling unit front section, a finish rolling water cooling device, a finish rolling unit rear section, a post-finish-rolling water cooling device, multi-lengths flying shears and a cooling bed are sequentially arranged in the rolling direction; rolling of a re-crystallization area is achieved by precisely controlling rolling temperature, austenite grains are refined, the rolling temperature of a critical austenitic area and ferrite re-crystallization area is precisely controlled through water cooling and a recovery section, deformation induced ferrite phase change and two-phase district ferrite phase change are achieved, perlitic transformation and little bainite transformation are achieved through after-rolling water cooling, strength, plasticity and toughness of the ribbed bars can be remarkably improved, and the ribbed bars have a low yield ratio and good plasticity, toughness, anti-seismic performance and welding performance. Meanwhile, the rolling fault rate is reduced through high-temperature rolling of a rough rolling area and an intermediate rolling area and production efficiency is improved.

The invention relates to a method for refining long-carbon chain dicarboxylic acid. A long-chain dicarboxylic acid crude product prepared by a fermentation method is used as a raw material, acetic acid is used as a solvent, and the refining and purification are performed by recrystallization treatment. The method comprises the process steps of bleaching filtration, cooling crystallization, centrifugal separation, centrifugal material washing, secondary centrifugation and drying, and is characterized in that a. the long-chain dicarboxylic acid crude product to be refined does not need to be dried; b. the acetic acid solvent is recycled by an azeotropic distillation method, and isopropyl acetate is used as an azeotropic dehydrating agent; and c. the isopropyl acetate is used as a centrifugal material washing solvent for replacing the acetic acid. The purification method of the long-carbon chain dicarboxylic acid provided by the invention has the advantages of distillation equipment investment conservation, low operating power consumption, good product color, high purity, high refining yield and low production cost, the long-carbon chain dicarboxylic acid to be refined does not need to be dried and dehydrated, and the acetic acid solvent is completely recyclable. The quality of the refined product can meet the technical requirements of use of condensed monomer raw materials used by synthesis of high polymer materials.

The production process features that dried and crushed flavescent sophora root is processed through extraction, concentration, alkalization, reduction, solvent extraction, acid reverse extraction, deposition and separation to produce coarse matrine product and coarse sophoridine product; coarse matrine product and coarse sophoridine product are recrystallized and dried to obtain matrine product and sophoridine product; and matrine is further processed through oxidation with hydrogen peroxide, decompression distillation, crystallization, filtering, re-crystallization and drying to obtain oxymatrine product. The said three products are material for producing medicine for treating hepatitis B, hepatitis C, leucopenia, arrhythmia, cancer and other diseases.The production process of the present invention is simple, low in cost, high in product purity and suitable for industrial production.

The invention discloses a preparation method of metformin hydrochloride. The preparation method is characterized by using dicyandiamide and dimethylamine hydrochloride as raw materials, feeding the materials in a mole ratio of (1:1)-(1:1.2), using N,N-dimethylacetamide or dimethyl sulfoxide 2-4 times dicyandiamide by weight as a solvent, and reacting for 4-8 hours at 140+/-5 DEG C to prepare a crude metformin hydrochloride product; recrystallizing the crude product with ethanol, regulating the pH value to be 5-6, decoloring the crystal, cooling the crystal to minus 10-0 DEG C while stirring, precipitating the crystal, obtaining a refined metformin hydrochloride product through filtering and drying, and recovering the solvent from filtrate. The qualified product has yield of 80-85% and high purity. The preparation method has the advantages that as the selected reaction solvent has a relatively high boiling point, the recovery rate of the solvent is high; the phenomenon of material surging can be effectively avoided, so that the preparation method has the advantages of mild reaction conditions, simplicity in operation and high safety.

The invention discloses a preparation method of ambroxol hydrochloride. According to the preparation method, a 'one-pot reaction' is adopted in the reaction, so that the separation of an intermediate is avoided, the operation is simple, the production period is short, the production cost is reduced, and the method is suitable for industrial production and application; the operation in refining the ambroxol hydrochloride is easy to carry out; and the ambroxol hydrochloride with purity more than 99.9% can be simply obtained by one-time recrystallization, so that the demand on preparation production can be met.

The EGCG fatty ester is prepared with natural catechin EGCG monomer and C12-C22 fatty acyl chloride in the molar ratio of 1-2 as material. In the presence of alkali catalyst or metal catalyst and in25-65 deg.c, fatty acyl chloride is dropped slowly into inert organic solvent containing catechin EGCG monomer; and through filtering, water washing, decompression concentration, re-crystallization and dewatering to dry, white solid EGCG fatty ester is prepared. The liposoluble EGCG fatty ester thus prepared has determined components, high antioxidant factor content, molecular structure capable of maintaining the structure features of catechin and even higher stability. The present invention may be used in medicine, edible vegetable oil, fried food, cosmetics, feed and other fields needing antioxidant additive.