34results about How to "Catalytic time is short" patented technology

The invention discloses a preparation method of a WO3/C3N4 mixed photocatalyst. The preparation method comprises the following steps: taking sodium tungstate and sodium chloride as the raw materials, preparing WO3 through a hydrothermal method, subjecting the WO3 to an ultrasonic dispersion treatment to obtain processed WO3; taking urea as the raw material, burning urea to obtain C3N4 in one step, subjecting C3N4 to an ultrasonic dispersion treatment to obtain processed C3N4; mixing the processed WO3 nano powder and processed C3N4 by a mechanical means and ultrasonic waves in sequence, washing the mixture, subjecting the mixture to a centrifugal treatment, and finally drying the mixture at a temperature of 70 to 80 DEG C to obtain the WO3/C3N4 composite photocatalyst. Under the same conditions, the catalytic degradation rate of rhodamine B of the provided photocatalyst is increased by 8%, compared with that of a conventional WO3/C3N4 composite photocatalyst, which is prepared through a grinding method; moreover, the catalytic time is shorter, and one hour after the starting of the catalytic reactions, the catalytic degradation rate of rhodamine B can reach 99%.

The invention discloses a trehalose synthetase as well as encoding genes and application thereof. The trehalose synthetase is a protein comprising one of the following amino acid residue sequences: 1) an SEQ ID No. 1 amino acid residue sequence in a sequence table; and 2) a protein which is derived from the SEQ ID No. 1, has trehalose synthetase related functions, and is obtained by replacing and/or deleting and/or adding the SEQ ID No. 1 amino acid residue sequence in the sequence table. Trehalose can be obtained by using maltose as a substrate and performing catalysis with the application of the protein of the trehalose synthetase; besides, the catalytic reaction has the advantages that the catalysis time is short, the concentration of the required substrate is low, a 90mM maltose is used as the substrate, the catalysis time is 8 hours, and the conversion rate reaches 69 percent.

The invention discloses a photo-anode for slowing down corrosion in a photoelectrocatalysis wastewater treatment process by using amorphous cobalt phosphate Co-Pi, a preparation method and applicationthereof. The method comprises the following steps: depositing a Bi metal film on the surface of a fluorine-doped tin oxide substrate under a dark condition; and dropwise adding a solution of vanadylacetylacetonate, annealing, converting the Bi metal film into a BiVO4 substrate film, soaking the BiVO4 substrate film in an electrolyte solution containing a chelating agent, applying a constant potential to obtain an electrode film, and electrodepositing cobalt phosphate to obtain the photo-anode. According to the method, an electrode film material is synthesized through simple photo-assisted electro-deposition, rapid capture and release of holes are completed in the process of photoelectrocatalytic degradation of organic micro-pollutants in water by utilizing the cyclic process of the valence state of a cobalt element in CoPi, and self-oxidation corrosion of an internal BiVO4/Cu2O photoelectrode is inhibited. The electrode film is easy to recycle, the crystal structure of the material is not changed after degradation experiments, and the electrode film is an environment-friendly material.

The invention discloses an electric-enhanced zero-valent-iron anaerobic water treatment device. The device comprises an up-flow anaerobic bioreactor, wherein an electric enhanced zero-valent-iron system is arranged in the middle of a barrel of the up-flow anaerobic bioreactor; the electric enhanced zero-valent-iron system comprises 2N electrodes formed by anodes and cathodes which are periodicallyarranged at intervals in the axial direction, wherein N is a positive integer; the anodes and the cathodes are connected with a direct-current power source outside the barrel through wires; and the space between every two adjacent electrodes are filled with a zero-valent-iron layer. According to the invention, on the basis of a zero-valent-iron coupling anaerobic reactor, a plurality of series orparallel electrodes are added, so that the over potential of a reaction is reduced, the electron obtaining rate of cathode microorganisms is accelerated, and the reduction reaction is promoted to berapidly carried out. An electric field is added, so that activity of the microorganisms can be stimulated, electron transfer between the electrodes and the microorganisms on the surface of the electrodes is facilitated, and the reaction rate of anaerobic zero-valent iron is enhanced to a greater extent.

The invention discloses an engineering bacterium for efficiently synthesizing pyruvic acid and D-alanine and a construction method and application of the engineering bacterium. On the basis of a genetic engineering strain BLK07 (pET20b-pm1), a strain with improved enzyme activity of pm1 is screened out through site-saturation mutagenesis, and an N-terminal encoding sequence (NCS) is inserted intoan N terminal of a gene sequence of the pm1, so that the protein expression quantity of the pm1 is improved, the yield of the pyruvic acid is increased, the catalytic time is significantly shortened and the catalytic efficiency is improved. When the concentration of substrates D-alanine and L-alanine is 110 g/L, the cell concentration is 4 g/L and a catalyst system only carries out catalysis at 37DEG C and 220 rpm in a shake flask for 8 h, the yield of the pyruvic acid can reach a maximum value 46.5 g/L, the conversion rate of the L-alanine is 84.5% and the resolution rate of the D/L-alaninereaches 84.5%.

A method of preparing xylitol by utilization of winter bamboo shoot shells is disclosed. The method includes: hydrolyzing the raw material winter bamboo shoot shells with sulfuric acid, neutralizing the obtained hydrolysate with CaCO3 emulsion to obtain a sugar solution, concentrating the sugar solution, decolorizing the sugar solution with activated carbon, purifying the sugar solution further by ion exchange, performing a hydrogenation reaction, concentrating the obtained hydrogenated sugar solution, crystallizing, separating to obtain a product that is the xylitol, and recovering the mother liquor. The method adopts the winter bamboo shoot shells as the raw material to prepare the xylitol and is simple in process, efficient and low in cost.

The invention discloses a method for preparing ginsenoside Rg3 through irradiation, belonging to the technical field of medicine preparation. The method comprises the following steps: with panaxadiolsaponins as a raw material, pretreating the panaxadiol saponins with an ethanol aqueous solution of an inorganic acid, then adding an irradiation auxiliary agent, and irradiating the panaxadiol saponins with energy of 1-15 kGy at normal temperature by virtue of a <60>Co-gamma ray irradiation technology; and carrying out purifying with an adsorption column to obtain the target product ginsenoside Rg3. According to the method, high-energy rays are adopted for strengthening acid selective hydrolysis, and the yield of ginsenoside Rg3 prepared through irradiation is greatly increased compared withthe yield of ginsenoside Rg3 obtained through common acid hydrolysis; catalytic time is shorter; the usage amount of acid is obviously reduced; and the output and yield of the target ginsenoside Rg3 are effectively increased. It is guaranteed that the preparation method is easy to operate, low in cost and high in efficiency.

The invention discloses a preparation method of energy-saving anti-ultraviolet polytrimethylene terephthalate. The preparation method is characterized by comprising the following steps: a first-stageesterification reaction: adding purified terephthalic acid, propylene glycol, an auxiliary agent containing a stabilizer and a titanium catalyst loaded with metal ions, and a titanium compound selected from at least one of nano titanium nitride, nano titanium oxide and nano zinc titanate into a polymerization kettle; replacing air in the polymerization kettle with inert gas, controlling the pressure in the polymerization kettle to be 0.1-0.4 MPa, controlling the rotating speed of the stirrer to be 50-120 r/min, controlling the temperature in the polymerization kettle to be 120-230 DEG C, calculating the esterification efficiency according to the water yield, and ending the esterification reaction when the conversion rate of terephthalic acid reaches 90-100%. The polytrimethylene terephthalate prepared by the method has excellent energy-saving and anti-ultraviolet properties, and also has the advantages of being not easy to degrade and good in color and luster.

The invention relates to a temperature-sensitive hairy polymer microsphere immobilized with L-proline. According to the preparation method, a P(EGDMA-co-HEMA) polymer microsphere is used as a core, atrithioester-based RAFT reagent is grafted, a polymer chain formed by copolymerizing NIPAM, N-boc-L-PolyA and MMA as monomers through a surface-initiated RAFT polymerization method to serve as a hairpart, and tert-butyloxycarboryl protection on the N-boc-L-PolyA is removed to obtain the polymer microsphere. According to the present invention, the L-proline immobilization amount on the temperature-sensitive polymer microsphere is large, the good catalysis effect is provided in direct catalysis of an asymmetric Aldol reaction in an aqueous phase environment, the catalysis reaction time is short, and the polymer microsphere can be separated from the catalysis system through simple centrifugal separation.

The invention relates to a preparation method of an ultraviolet broadband photocatalyst, belonging to the field of photocatalyst preparation. For the currently prepared TiO ₂ The photocatalyst has a large bandgap and can only respond to the ultraviolet light part which accounts for 3% to 5% of the solar spectrum. The utilization rate of solar energy is not high, and its photocatalytic effect cannot be fully exerted. Mixing acid to prepare salicylate resin, and then dispersing and mixing nano-titanium dioxide and salicylate to prepare photocatalyst, absorbing ultraviolet rays through salicylate, and then undergoing molecular rearrangement under ultraviolet irradiation to minimize its ultraviolet absorption Function, the UV broadband photocatalyst prepared by the present invention has a UV absorption wavelength of 350-380nm, high catalytic efficiency, 30-45% reduction in catalytic time, and a decolorization rate of over 93%. The preparation and operation are simple and environmentally friendly.

The invention discloses a molecularly imprinted polymer for targeted degradation of emerging pollutants based on an advanced oxidation system as well as a preparation method and application of the molecularly imprinted polymer. The preparation method comprises the following steps: adding emerging pollutants and acrylic acid into a pore-forming agent, pre-assembling, adding MOFs, divinyl benzene and azodiisobutyronitrile under a protective atmosphere, and carrying out a water bath reaction; and centrifugally separating, washing and drying the reacted mixture to obtain the molecularly imprinted polymer. The molecularly imprinted polymer disclosed by the invention can be continuously used, still has good adsorption and activation effects after being used for multiple times, and is an environment-friendly material. The method is suitable for various emerging pollutants, is good in durability, short in catalysis time and convenient to operate, has a relatively high degradation effect on the pollutants, reduces the pollutant degradation cost, and has a great application prospect in the aspect of degrading the emerging pollutants.

The invention relates to a method of preparing levulinic acid via hemicellulose. The method comprises the steps of screening hemicellulose which is 200-400 mesh, preparing hemicellulose liquid havinga concentration of 15-25% with a dual-water-phase solvent, adding the prepared hemicellulose liquid into a reactor, adding 5-10% of a mixed solution of formic acid, acetic acid and iron chloride, 1-5%of a tin porous carbon-based solid acid catalyst, 0.5-1.0% of Raney nickel-alumina-ZSM5 catalyst, and 0.3-0.8% of Au-ZrO2-SBA15 catalyst, stirring while temperatures are controlled in different periods of time, introducing hydrogen for a period of time, holding the set temperature for a period of time, and preparing to obtain levulinic acid solution. few byproducts occur to the preparation of levulinic acid; subsequent separation and purification are simple; the yield of levulinic acid is increased; one-step preparation of levulinic acid by hemicellulose is achieved.