216 results about "Gut duplication" patented technology

Disclosed are a preparation method and application of heterogeneous Fenton-like catalyst. The preparation method includes the steps of firstly, dissolving complexing agent and metal salt in distilled water to respectively prepare complexing agent and metal salt solutions; secondly dropwise adding the metal salt solution into the complexing agent solution under the action of a magnetic mixer, and mixing for 20-60 after dropwise addition to obtain metal complex solution; and thirdly, impregnating activated carbon fiber in the metal complex solution for 1-24h, and subjecting taken-out activated carbon fiber to distilled water washing and drying to obtain the heterogeneous Fenton-like catalyst. The preparation method is simple, and conditions are mild. Environment-friendly hydrogen peroxide is used as oxidant, no extra ultraviolet light or even visible light is needed, and the heterogeneous Fenton-like catalyst is capable of efficiently degrading organic pollutants such as dye within a wide pH range of 2-10. The heterogeneous Fenton-like catalyst is well repeatable, and secondary pollution of the homogeneous Fenton reagent caused by iron ions is avoided.

The invention discloses a method for synthesizing 2,5-furandicarboxylic acid through catalytic oxidation by using 5-hydroxymethylfurfural as a raw material. 5-hydroxymethylfurfural can be oxidized by using oxygen or air as an oxidant in the presence of a catalyst prepared by loading an alkaline carrier with noble metal with high efficiency and high selectivity to synthesize 2,5-furandicarboxylic acid. A catalytic reaction is easy to operate and mild in conditions; when 5-hydroxymethylfurfural is fully converted, the selectivity of the product-2,5-furandicarboxylic acid can reach more than 99%; the catalyst is good in reusability.

The invention relates to a method for simultaneously detecting three antibiotic residues including streptomycin, chlorampenicol and tetracycline based on nucleic acid aptamers and quantum dots and belongs to the technical field of analytical chemistry. Three-section complementary cDNA 1 sequences are designed and synthesized and are complemented with three antibiotic aptamers DNA sequences and are further complemented with respective capturing probe DNA sequences of three antibiotics and complementary cDNA 2 sequence part. The three cDNAs 1 are first hybridized with aptamer DNAs supplemented with each other to form double-stranded DNAs. When target antibiotics exist in a sample, the aptamer DNAs are combined with corresponding antibiotics as a priority to cause the double-stranded DNAs to be de-hybridized and release cDNAs 1. The free cDNAs 1 are combined with capturing probe DNAs modified on the surface of a gold electrode, and cDNAs 2 modified with three quantum dots are hybridized with the other end of each cDNA 1. The three quantum dots on the surface of the gold electrode generate dissolution volt-ampere peaks corresponding to the target antibiotics. The three antibiotics are detected by utilizing the relations of changes of peak current values and antibiotic concentration. The method is good in repeatability and stability and high in sensitivity and can be used for directly measuring the three antibiotic residues in samples such as milk.

Using single circular ring type static sensor, the invention implement measures average velocity of grains, simplifies measuring device, and reducing dependence of flow condition between two phases of gas and solid. Belonging to non-contact type, the static sensor does not influence on flow condition of liquid in structure. Based on spatial filtering method of static sensor, the technique for measuring average velocity of grains possesses features of simple structure, convenience of processing signal, low cost, and high measuring accuracy. The invention is applicable to site environment of inclement industrial pneumatic transport. The invention carries out experimental study systematically on experimental installation of gravity handling grain flow, and compressive dense phase pneumatic transport system. The result indicates that the measuring system possesses good repeatability and stability.

The invention relates to a high-flux molecular-sieve alcohol permselective membrane and a preparation method thereof. The high-flux molecular-sieve alcohol permselective membrane is composed of a support body and a membrane layer, wherein the support body is yttrium-stabilized zirconia porous material, the membrane layer is a Silicalite-1 molecular sieve membrane, the average pore size of the support body is 0.1-5 mu m, and the porosity is 10-75%. The invention also discloses a preparation method of the hollow fiber alcohol permselective membrane. The alcohol permselective membrane has outstanding separating property. When the alcohol permselective membrane is used in an ethanol/water system, the permeation flux is enhanced by 3-20 times. The alcohol permselective membrane has higher separation factor and favorable repetitiveness, and especially has favorable effect since the alcohol permselective membrane is composed of the hollow fiber support body. The alcohol permselective membrane is used in the fields of permeating vaporization, gas separation and the like, and has important meaning in the industrial application of alcohol fermentation liquor concentration.

The invention discloses a detection method of a kanamycin residue based on a nucleic acid aptamer, and belongs to the technical field of analytic chemistry. The method comprises the steps that by using a sulfydryl covalent modification mode, ssDNA (single-stranded Deoxyribonucleic Acid) complementary with the two ends of a kanamycin aptamer is modified on the surfaces of AuNPs (Gold Nanoparticles) respectively; two kinds of functionalized AuNPs are obtained; the kanamycin aptamer is added and pairwise bound with ssDNA on the surfaces of the functionalized AuNPs; spatial distances among the AuNPs are closed; the AuNPs are mediated to be aggregated; after the AuNPs are mixed with kanamycin samples with different concentrations, specific binding between kanamycin and the aptamer allows an aggregation to be disaggregated, which is manifested by a change of an AuNPs characteristic absorption peak in an ultraviolet-visible spectrum; and the kanamycin residue is detected by using a relation between a change of the absorbency at a 527-nanometer part and the concentration of the kanamycin. The method is good in repeatability and stability, easy to operate and high in sensitivity, and can be used for directly determining the kanamycin residues in samples such as pretreated milk.

The invention relates to an oil-water separation type sodium alginate/graphene oxide composite aerogel and a preparation method thereof. The preparation method of the oil-water separation type sodium alginate/graphene oxide composite aerogel comprises the following steps: preparing a sodium alginate/graphene oxide mixed solution, preparing an uncrosslinked sodium alginate/graphene oxide composite aerogel, and preparing the oil-water separation type sodium alginate/graphene oxide composite aerogel. The oil-water separation type sodium alginate/graphene oxide composite aerogel has a highly porous structure, a complete three-dimensional network and a high separation efficiency, has a separation rate of above 99.9%, has high salt resistance, is suitable for being used in high-salinity sea environments, and also has the advantages of good elasticity, high mechanical strength, oil pollution resistance, realization of almost no reduction of the separation efficiency after reuse 40 times or more, and good reuse ability.

The invention belongs to the field of biological detection reagents and relates to a kit for indirect ELISA (Enzyme-Linked Immunosorbent Assay) detection of IgG or IgA antibodies of PRRSV (Porcine reproductive and respiratory syndrome virus) of pigs. The kit is used for indirect ELISA detection of the IgG or IgA antibodies of the PRRSV in serum or saliva of pigs and comprises (a) an antibody detection board, (b) an HRP-labeled goat anti-pig IgG antibody solution or HRP-labeled goat anti-pig IgA, (c) a positive control, namely PRRSV standard positive serum or saliva, (d) a negative control, namely PRRSV negative serum or saliva, (e) sample diluting liquid, (f) 10* concentrated washing liquid, (g) substrate developing liquid, and (h) stopping liquid. The kit is good in PRRSV specificity and sensitivity when being used for detection of PRRSV IgG or IgA antibodies in serum or saliva of pigs. A repeatability test also shows that the kit is good in repeatability.

The invention discloses a load type CoB catalyst for process of preparing hydrogen through hydrolysis of sodium borohydride. The load type CoB catalyst is a CoB/Ag-TiO2 catalyst prepared by steps of sensitizing a TiO2 carrier by using a sensitizing agent solution and carrying out chemical plating by using a chemical plating solution, wherein the mass percent of the load quantity of Co is 1-15 percent, and the mass percent of silver is 0.2 percent. The prepared CoB/Ag-TiO2 catalyst and an Mo and W modified CoB/Ag-TiO2 catalyst have high catalysis activity for a reaction for producing hydrogen through hydrolysis of sodium borohydride, show excellent reuse capacity, are very high in stability in air, and are very suitable for the demand of actual hydrogen production.

The invention discloses a method for preparing Sb-intermingled growing p-type ZnO crystal film, including the step of: weighing ZnO and SbO3 powder, wherein mol percent of Sb is 1.5-4%, mixing the powders uniformly by ball milling and compressed molding, and sintering them to produce Sb-intermingled ZnO ceramic target; placing the ceramic target and the substrate into the the growing chamber of pulse laser depositing apparatus, growing the film on the substrate by the pulse laser depositing method, annealing at the oxygen atmosphere after growing, cooling them to room temperature. The inventive method is simple, different-intermingling-concentration p-type ZnO crystal film can be produced by adjusting mol percent of Sb in the target matarials, and high-concentration intermingling can be carried out because intermingled elments come from the target materials; SbZn-2VZn complex is produced by making Sb to occupy the position of Zn, while to be induced to produce both empty positions of Zn, compared with N element in V group the producing energy of the complex is lower, accordingly the produced p-ZnO film has good the repeatability and the stability.

The invention relates to a polyaniline (PAn) modified ordered mesoporous carbon (EOMC) immobilized laccase biosensor and a preparation method. The biosensor is characterized in that enzyme, EOMC+Lac and an EOMC+Lac/PAn modified gold electrode can be better immobilized by covering the periphery of mesoporous carbon with a layer of PAn film. The biosensor and the preparation method have the following beneficial effects: the gold electrode modified by the PAn modified EOMC immobilized laccase can show good direct electrochemical behavior; under the experimental conditions that the room temperature is 25+/-2 DEG C, the pH value of phosphate buffered solution is 5.0 and the working voltage is +0.45V vs SCE, compared with the EOMC+Lac/Au electrode which is not modified by PAn, the EOMC/PAn+Lac/Au electrode shows better sensing property; the linear detection range of p-pyrocatechol of the EOMC/PAn+Lac/Au electrode is 0.55-10.45mu M, the selective sensitivity of the EOMC/PAn+Lac/Au electrode is 0.08314A/M (n=19), the apparent Michaelis constant of the EOMC/PAn+Lac/Au electrode is 11.5327mu M and the detection limit of the EOMC/PAn+Lac/Au electrode is 0.173mu M (S/N=3); and besides, the laccase biosensor also shows good repeatability and stability; therefore, the PAn modified mesoporous carbon is expected to become a composite for immobilizing laccase and a new thinking is provided for modifying the immobilized enzyme by the mesoporous carbon.

The invention discloses preparation of anion-modified solid base and application of the same in biodiesel preparation reaction by a catalytic ester interchange method. The catalyst is directly prepared from metal nitrate, metal oxide and ammonium halide under the alkaline condition by a one-step method. The preparation method is simple to operate, and the catalyst has low cost. In the biodiesel preparation reaction by the ester interchange method, the catalyst has high catalytic activity, good reusability and mild reaction conditions, and does not pollute the environment.

The invention relates to a phenylboronic acid modified magnetic nanoparticle, and a preparation method and application of the phenylboronic acid modified magnetic nanoparticle, and belongs to the technical field of nano materials. Firstly, a magnetic silicon dioxide nanoparticle is prepared, a sulfydryl modified magnetic nanoparticle is prepared through a silanization reaction, the sulfydryl modified magnetic nanoparticle is then dissolved in ethyl alcohol, 4-vinyl phenylboronic acid and AIBN (azodiisobutyronitrile) are then added, the mixture is stirred and reacts in a water bath kettle, a product is magnetically separated, an obtained solid is washed through distilled water and ethyl alcohol and dried to obtain a final product of the phenylboronic acid modified magnetic nanoparticle; and the obtained material is used in enrichment and separation of fructose. The synthesized magnetic material has the advantages of excellent nuclear shell morphology, and can be rapidly separated in an externally applied magnetic field; the adsorption efficiency of fructose of a magnetic microsphere is 6 times that of glucose, the application effects of enrichment and separation of fructose are quite good, and meanwhile, the phenylboronic acid modified magnetic nanoparticle is excellent in repeatability.

The invention discloses a polymer matrix composite material with high PTC strength and stability and a preparation method thereof, and the composite material comprises UHMWPE and PVDF, CB and MWNT conductive filling materials which are treated by surface treatment by a titanate coupling agent, and an antioxidant 1010; the preparation method comprises the following steps: performing surface treatment of the CB and MWNT conductive filling materials by the titanate coupling agent, performing vacuum drying of PVDF and UHMWPE with a volume ratio of 1:1, adding PVDF into a torque rheometer, heating and melting for 2 min, adding another matrix of UHMWPE and the antioxidant 1010, wherein the amount of the antioxidant 1010 is 1% of the total mass of the matrix; mixing the mixture of the two matrixes for 10 min, adding the filling materials, mixing at 250 DEG C for 15 min; after melt blending, performing hot pressing with a constant temperature of 250 DEG C and a constant pressure of 18 MPa for 10 min to obtain the sample. The composite material of the invention has good conductivity and low room-temperature conductivity, and has a conductivity of up to 10-1 near a percolation threshold; the conductivity of the composite material can be changed by adjusting the contents of the filling materials in the composite material; the composite material has high PTC strength, good repetition stability, and reduced NTC effect.

The invention discloses a method for distinguishing the high temperature yeast. The flavor components of the yeast are analyzed by a head space solid phase microextraction technology and a gas chromatography-mass spectrography technology, and the quality of the yeast is distinguished by analyzing data by a judgment and analysis method. According to the method provided by the invention, a head space solid phase microextraction sample injection method is optimized; and the optimal condition of analyzing the flavor substances of the yeast is obtained. The method of the invention is scientific, rational, high in accuracy, high in feasibility and high in repeatability and sensitivity and can effectively distinguish samples under judgment analysis; and the correctness is over 95 percent.

The invention discloses a three-dimensional graphene foam flexible strain sensor and a preparation method thereof. The three-dimensional graphene foam flexible strain sensor comprises three-dimensional graphene foam; the two ends of the three-dimensional graphene foam are coated with conductive colloid; electrodes are arranged in the center of the upper surfaces of the conductive colloid, and cured high-molecular polymers are arranged on the peripheries of the three-dimensional graphene foam and the conductive colloid. According to the preparation method of the three-dimensional graphene foamflexible strain sensor, graphene is attached to a polymer template, and the three-dimensional graphene foam flexible strain sensor based on the polymer template is prepared after permeation of a high-molecular polymer material. The sensor disclosed by the invention has the advantages of high strain capacity, high sensitivity, flexibility, low cost, simple preparation method and good repeatabilityand consistency.

The invention belongs to the technical field of electronic materials. Multi-element doped high-performance beryllium oxide ceramic material, in addition to beryllium oxide, also includes 0.2-0.6% by mass of multi-element dopant; said multi-element dopant is composed of MgO, Al2O3, SiO2, CaO, ZnO and rare earth oxides , the mass percentage content of each component is: MgO: 5-60%, Al2O3: 0-40%, SiO2: 20-95%, CaO: 0.1-0.5%, ZnO: 0-0.5%, containing Y, La, Single or random mixed rare earth oxides of Ce or Sm: 0.01-0.5%. The multi-element dopant is prepared by a sol-gel method, and then mixed with a high-purity beryllium oxide raw material, shaped and sintered at a high temperature to obtain the multi-element doped high-performance beryllium oxide ceramic material of the present invention. The multi-component doped high-performance beryllium oxide ceramic material provided by the invention has lower sintering temperature, higher density, thermal conductivity and mechanical properties; its microstructure has the characteristics of compactness, uniform crystal grains and few pores. The preparation method has simple process, low production cost and good repeatability, and is suitable for industrialized production.

The invention provides an electrochemical detection method for detecting kanamycin residues based on a nucleic acid aptamer and a nano analogue enzyme and belongs to the technical field of analytical chemistry. Gold nano-particles are synthesized by reducing chloroauric acid through tyrosine, and hydrogen peroxide and reduced-state thionine are catalyzed to react to generate oxidized-state thionine; and the thionine can be detected through a difference pulse voltammetry. The gold nano-particles are modified through utilizing a kanamycin specific aptamer; and the aptamer is adsorbed on the surfaces of the gold nano-particles so that the peroxidase activity is inhibited. When a target object kanamycin exists, the aptamer can be competitively replaced from the surfaces of the gold nano-particles to form a compound, so that the peroxidase activity is recovered. The detection of the kanamycin can be realized through detecting a relation between a reduction peak current value of the oxidized-state thionine and an antibiotic concentration by utilizing the difference pulse voltammetry. The method provided by the invention has good repeatability, good stability and high sensitivity, and can be used for effectively detecting kanamycin residues in food samples.

The invention provides a preparation method of a red fluorescent silver nanocluster. Egg white is taken as a template and a protective agent; sodium borohydride is taken as a reducing agent; and "one kettle way" is utilized to prepare the silver nanocluster with uniform size, good stability, and red fluorescence. The method is simple to operate, relatively low in cost, and excellent in repeatability, and the raw materials are widely available. The prepared red fluorescent silver nanocluster is good in water solubility and strong in stability, and is applicable for testing mercury ions in a water system.

The invention relates to a heterogeneous cage-form metal complex catalyst as well as a preparation method and application. The catalyst is prepared by forming a cage by virtue of benzene-containing carboxylic acid and metal salt, and adopting a solvothermal method in a mixed solvent by taking metal complex or biological enzyme as a template. The prepared cage-form catalyst loaded with the metal complex is used for decoloring printing and dyeing wastewater. The catalyst has the advantages that the preparation method is simple, the environment is mild, environmentally-friendly hydrogen peroxide is taken as an oxidizing agent, and organic pollutants such dyes can be effectively degraded in a wide alkaline pH range, namely 7-14; furthermore, the reusability is good, and the secondary pollution caused due to a high acidic environment of a homogeneous Fenton reagent and iron ions is avoided.

The invention discloses a method for preparing a zinc oxide nano sheet array, which comprises the following steps that: zinc oxide (ZnO) seed crystal solution is firstly prepared, spin coating is completed on a base, then a reaction liquid for ZnO nanosheets to grow is prepared, the base which is spin-coated with the seed crystal solution is put into the reaction liquid and is sealed, so the zinc oxide nano sheet array grows. The invention has the characteristics of quickness and convenience, has good repeatability, and can produce the zinc oxide nano sheet array on any base in a large area, expansive instruments, complicated technological conditions and harsh experimental parameters are prevented from being used, and the reaction time is finely regulated to observe the microstructure of the surface of a cover glass.

The invention relates to the preparation of a polyphenol oxidase biosensor, which is prepared by adopting carbon nanosphere embedded polyphenol oxidase modified glassy carbon electrode and used for detecting pesticide residues. Polyphenol oxidase is a class of metalloproteinases with wide sources, compared with acetylcholinesterase, butyrylcholinesterase and organophosphorus hydrolase and the like, the polyphenol oxidase has the advantages of wide sources, low price and the like. According to the invention, carbon nanosphere is adopted to embed polyphenol oxidase, and has good biocompatibility, higher mechanical strength and larger specific surface area, so that the fixed quantity of an electrode surface enzyme is improved, and the biological activity of the polyphenol oxidase is maintained to the maximum degree. Therefore, the biological catalytic efficiency of the enzyme, and analysis and detection performance of the biosensor are improved. The polyphenol oxidase biosensor prepared through the method has lower detection limit and an excellent linear range to glyphosate, and has excellent recovery rate to sample detection, meanwhile, has excellent repeatability, reproducibility and stability, and can be used for detecting pesticide residues.

An optical receptacle includes: a fiber stub having a ferrule and an optical fiber in a through-hole of the ferrule; a holder to which an rear end of the fiber stub is fixed; and a sleeve for holding a plug ferrule in front of the fiber stub; wherein a grip ring is provided on an outer side face in which the fiber stub and the sleeve are overlapped to each other, whereby attaining the shortened optical receptacle, and improving connection loss due to tilting of the plug ferrule, and obtaining good repeatability of the connection loss.

The invention discloses a preparation method for composite activated biochar capable of adsorbing heavy metal ions in sewage. According to the preparation method, a saponification-modified orange peelbio-adsorbent, an obtained pine needle-based carbon material, puffed rice husks, a chestnut shell activated carbon material and walnut green husk biochar are uniformly mixed so as to obtain the composite activated biochar. The preparation method has the advantages that pine needles serve as a carbon source, alkali treatment is carried out, then carbonizing is carried out, so that the pine needle-based carbon material with developed pore channel structures and high nitrogen content is successfully prepared, by means of the developed pore channel structures and rich nitrogen-contained functional groups, and the prepared pine needle-based carbon material shows good adsorption performance on the metal ions and has good repeated use performance; chestnut shells serve as a raw material, activated carbon is prepared by adopting a ZnCl2 activation method, the chestnut shell activated carbon is an amorphous carbon material with more pores; and biological waste orange peels serve as a raw material, and ethanol and sodium hydroxide treatment are carried out so as to obtain the modified orange peel biological adsorbent.