30results about How to "Overcome the disadvantage of low yield" patented technology

The invention discloses a preparation method of pyrophosphate piperazine. The preparation method comprises the following steps: mixing ammonium dihydrogen phosphate and piperazine in an aqueous solution according to a mole ratio of 2:1, heating to remove ammonia, and dewatering for condensation to obtain the pyrophosphate piperazine. According to the preparation method, the shortcomings that conventional liquid phosphoric acid serving as a phosphorous source is difficult to transport and store are overcome; a reaction system is a weak-alkaline environment, so that erosion of the phosphoric acid serving as the phosphorous source to equipment is avoided; ammonia released during reaction can be used as protection atmosphere of the reaction system, and the whiteness value of a product meets the market requirement. Compared with a phosphoric acid-piperazine method, the preparation method has the advantage of saving the raw material cost by 10 to 15 percent.

The invention discloses a method for preparing (phthimide-N-oxyl) derivatives by direct coupling of NHPI (N-hydroxyphthalimide) and ketone compounds. The method includes that, under the protection of nitrogen, the ketone compounds react with N- hydroxyphthalimide and K2S2O8 under catalyzing of tetraalkyl ammonium salt to generate the PINO derivatives. With the method, the PINO derivatives are synthesized with high yield by one-step reaction under the moderate condition, low cost is achieved, simpleness in operation is realized, and industrial production requirements are met.

The invention relates to a preparation method of a metal organic framework material MIL-88B(Fe). The preparation method comprises following steps: 1, an iron source and an organic ligand are mixed to be uniform, and are subjected to pretreatment for 1 to 3h so as to obtain an intermediate; 2, the intermediate is added into ethanol solvent, and an obtained mixture is stirred at room temperature, and then is subjected to centrifugation so as to obtain a crude product; 3, the crude product is washed with ethanol for a plurality of times, and then is dried so as to obtain the metal organic framework material MIL-88B(Fe). Compared with the prior art, toxic organic solvents such as N,N-dimethylformamide used in conventional solvothermal method is not used, ethanol is taken as a solvent, the raw material is subjected to pretreatment, synthesis of MIL-88B(Fe) is realized at room temperature, the conditions are mild, yield is relatively high, and it is possible to realize large-scale synthesis of metal organic framework materials.

The invention relates to a filling mining method for a caving zone on a coal face and the method can effectively solve the problems that coal filling mining is greatly limited by space of the coal face, time and floor space, and the coal mining efficiency on the coal face is low. The invention adopts the technical scheme that the method comprises the following steps: (1) excavating a special filling roadway; (2) establishing ground filling stations; (3) determining the filling interval of each cycle; (4) drilling grouting holes and connecting pipelines; (5) conducting filling operation; and (6) conducting cycle mining. Compared with other filling methods, the method provided by the invention is free from limits of space of the coal face, time and floor space, can be matched with any coal mining technology under appropriate conditions, can easily achieve high yield and high efficiency on a filling face through the combination with a fully mechanized top coal caving mining method, overcomes the defect of low yield of the conventional filling face, and has favorable social and economic benefits.

The invention relates to a preparation method of a metal organic framework material MIL-100 (Fe), which comprises the following steps: proportionally adding an organic ligand and an iron source into a certain amount of deionized water, and mixing for 30 minutes; mixing the mixture obtained in the step (1) at 80-95 DEG C under atmospheric pressure to react for 5-20 hours; and filtering the solid obtained in the step (2), washing with anhydrous ethanol at 60-80 DEG C for 10-20 hours, treating with a 30-60 mmol / L ammonium fluoride solution at 60-80 DEG C for 10-20 hours, sufficiently washing with deionized water, and finally, drying at 100-200 DEG C for 5-10 hours to obtain the pure MIL-100 (Fe). The method has the advantages of mild synthesis conditions, high product yield and high product quality.

The invention discloses a method for secondary immobilization of Debaryomyces hansenii with a composite material. The method includes the steps of: employing sodium alginate and activated carbon to immobilize Debaryomyces hansenii; using polyvinyl alcohol and sodium alginate to perform secondary immobilization of Debaryomyces hansenii; and placing the Debaryomyces hansenii subjected to secondary immobilization in a fermentation medium for culture. The preparation method provided by the invention has the characteristics of novelty, simplicity, easily controllable operation program, and high yield, and overcomes the disadvantage of low 3-hydracrylic acid yield of traditional strains.

The invention discloses a nitrogen-doped activated carbon supported noble metal catalyst and an application thereof. The catalyst is composed of a carrier and an active component; the carrier is nitrogen-doped activated carbon; the active component is one of palladium, platinum, rhodium, ruthenium and iridium; and the load of the active component is not higher than 15wt% based on the mass of the carrier. The invention provides the application of the nitrogen-doped activated carbon supported noble metal catalyst to reaction for preparing an alkyl-containing halogenated aromatic aminocompound shown as a formula (II) by carrying out catalytic hydrogenation reduction on an alkyl-containing halogenated aromatic nitrocompound shown as a formula (I) to show that the nitrogen-doped activated carbon supported noble metal catalyst has the characteristics of high hydrogenation reaction rate, high catalytic activity, high selectivity and high stability.

The invention relates to a method for preparing a metal organic framework material UiO-66 (Zr) in an ethanol phase. The method comprises the following steps: (1) uniformly mixing a zirconium source and an organic ligand, and pretreating for 1-3 hours so as to obtain an intermediate; (2) adding the intermediate into ethanol, stirring under a normal temperature condition, and centrifuging so as to obtain a crude product; and (3) washing the crude product for multiple times with ethanol, and drying, thereby obtaining the metal organic framework material UiO-66 (Zr). Compared with the prior art, the method is not involved with toxic organic solvents such as N,N-dimethyl formamide used in a conventional solvent thermal method, after the raw materials are pretreated, the UiO-66 (Zr) can be synthesized by using the ethanol as a solvent under the room temperature condition, the condition is gentle, the yield is relatively high, and large-scale synthesis of metal organic framework materials is possible.

The invention discloses a hydrogenation valve and a machining method thereof. The machining method comprises the steps of preparing or selecting suitable self-lubricating high polymer materials according to the characteristic requirements for a hydrogenation valve pressing plate and a valve rod connecting nut, utilizing the high polymer material coating surface treatment technology for coating the surface of a valve rod with the self-lubricating high polymer materials, solidifying the coated self-lubricating high polymer materials for more than 30 min at room temperature, and then conducting automatic friction center adjusting cooperation on the hydrogenation valve movable joint nut and the valve rod with the surface coated with the self-lubricating high polymer materials. The hydrogenation valve and the machining method of the hydrogenation valve have the advantages that the coaxiality of the conical surfaces of the two ends of the valve rod of the hydrogenation valve does not need to be ensured; the self-lubricating high polymer materials coating the surface of the valve rod have good friction resistance and good wear resistance, and the hardness of the self-lubricating high polymer materials is lower than that of the valve rod connecting nut making contact with the self-lubricating high polymer materials, so that the automatic friction center adjusting cooperation is carried out on the valve rod and the valve rod connecting nut, the phenomena that due to the facts that eccentricity is excessive and the valve rod is extruded, the valve rod is abraded and broken, and the valve rod connecting nut is abraded are avoided, and meanwhile the pressing plate is prevented from being scratched.

The invention discloses a colony, expression and appliance of lactic acid bacteria aminoglutaric acid decarboxylase gene in food industry biotechnics domain, which is characterized by the following: coming from spittle streptococcus thermophilic subspecies (Streptococcus thermophilus) with length at 1380bp; augmenting from gene group DNA through PCR; adding NcoI and EcoRI on the two ends of the gene; limiting enzyme identification sequence; connecting to pET-DsbA of same limited enzyme alimentary; transforming expressing host bacteria BL21(DE3)pLysS of bacillus coli; realizing retooling expression in bacillus coli; getting glutamic acid decarboxylase molecule with molecular weight at 52. 4kDa; transforming L- glutamic acid decarboxylase to gamma-aminobutyric acid with retooling enzyme; providing a great amount of and high active rough enzyme for enzymatical synthesis of gamma-aminobutyric acid; decreasing cost of enzymatical synthesis of gamma-aminobutyric acid. This method possesses warm condition, which belongs to biological synthesis method.

The invention discloses a method for preparing high-whiteness short columnar submicron α-hemihydrate gypsum from desulfurized gypsum. The method comprises the following steps: adding N.N'-methylenebisacrylamide, water, and desulfurized gypsum into a reaction vessel for mixing to prepare a reaction slurry, and heating the slurry to 120-125°C for 2-5 hours; filtering , washed to neutral and then dried to obtain an intermediate product; mix water, intermediate product, NaCl, succinic acid, and ethylene glycol to prepare a reaction slurry; then react the reaction slurry at a temperature of 120°C to 125°C and stir for a homogeneous reaction The reaction is carried out in a device for 3 to 4 hours; after filtration and drying, a short columnar submicron α-hemihydrate gypsum with high whiteness is obtained. The invention not only solves the problem of accumulation and secondary pollution of waste resource desulfurized gypsum, but also provides a new method for producing small particle gypsum with high whiteness and certain strength.