85results about How to "Simple pre-processing" patented technology

The invention relates to a processing technology of a spinning belt pulley with inner and outer lug bosses, which belongs to the field of manufacturing belt pulleys. The processing technology comprises the following steps of: stamping and performing a blank, reprocessing the performed blank and spinning the reprocessed and performed blank, wherein the reprocessing step of the performed blank comprises the following steps of: cold extruding a formed blank A into a performed blank B with a predetermined size; and rolling and forming the performed blank B by a spinning mode to form the performed blank C with inner and outer lug bosses. Compared with the traditional processing technology, the processing technology of the spinning belt pulley with the inner and outer lug bosses has wide source of raw materials, low cost, high production efficiency and low rejection rate, the spinning mode is used for replacing a stamping mode to produce the blank with the inner and outer lug bosses, products are not easy to deform, the dimensions of the product can achieve higher required precision, and an adopted spinning machine has small erosion, low power consumption and convenient maintenance.

The invention relates to a method for increasing anaerobic fermentation gas yield of energy grasses. According to the method, the energy grasses are subjected to ensiling pretreatment, and lactic acid bacteria and cellulase are added at the same time during ensiling so as to change the fiber structure of the energy grasses and increase the total amount of fermentable dry matters in an ensilage raw material, thus the anaerobic-fermentation methane production efficiency of the energy grasses is increased remarkably. The method for increasing the anaerobic fermentation gas yield of the energy grasses, provided by the invention, is a biological method, ensilage additives are all biological raw materials, and ensiling is also a biological process, so that the gas production efficiency of the energy grasses can be increased remarkably, and secondary pollution can not be caused; the whole process is simple in operation and is safe and reliable, the used raw materials are wide in source and low in cost, the requirements for production sites are low, the industrial large-scale production can be carried out, and the cost is remarkably lower than that of other bioenergy, such as fossil energy, bioethanol, biodiesel and the like, so that the method has market competitiveness.

The invention relates to an LC-MC method used for determining NNK metabolites in liver microsomes and specifically to an LC-MC method used for analyzing and determining 4-(methyl nitroso)-1-(3-pyridyl)-1-butanone (NNK) metabolites in liver microsomes, which belongs to the field of biochemical analysis. The method provided in the invention mainly comprises the following steps: (1) preparation of an incubation system for liver microsomes; (2) sample treatment; (3) sample analysis and determination of NNK metabolites in the liver microsomes by using the LC-MC method. The invention has the following advantages of simple pre-treatment, a fast analysis speed, good selectivity, high detection sensitivity and capacity of analyzing and comparing the metabolism of NNK in different kinds of liver microsomes, can lay a methodological foundation for further research on in-vivo and in-vitro metabolism of NNK and other nitrosamine compounds and has critical significance.

The invention discloses a composite silica gel column and a pretreatment method for simultaneously measuring multi-type persistent organic contaminants in sediments and biological samples. The composite silica gel column comprises glass wool, silver silicate silica gel, activated silica gel, alkaline silica gel, activated silica gel, first acid silica gel with the acid content of 40 wt%-50 wt%, second acid silica gel with the acid content of 20 wt%-25 wt%, activated silica gel and anhydrous sodium sulfate sequentially from bottom to top.

The invention belongs to the technical field of analytic chemistry, and particularly relates to a method for determining the content of chloromethyl methyl ether in automotive materials. The method comprises the following determining steps: (1) cutting a to-be-determined sample into small cubes with sizes of about 2mm*2mm*2mm, and sealing for later use; (2) weighing a certain amount of sample and placing the sample in a headspace bottle, adding acetone, adding toluene-d8 as an internal standard, after fastening the bottle cover down, placing in a headspace sampler; and (3) determining the content of chloromethyl methyl ether in a sample by adopting a gas chromatography-mass spectroscopy meter. According to the method, the content of chloromethyl methyl ether in the automotive materials is determined by adopting the gas chromatography-mass spectroscopy meter, and is quantified by adopting an internal standard method; the method is little in sampling amount, simple in pretreatment operation, and rapid in testing; accurate determination of the content of chloromethyl methyl ether in the automotive materials can be realized, and the detection limit of the method is 100mg/kg.

The invention relates to a method for detecting melamine by ion chromatography. The method comprises the following steps of: pretreating a sample to be detected by using an on-line osmotic membrane method to obtain an extracting solution of the sample; analyzing a peak area of the extracting solution of the sample by using an ion chromatograph, and comparing with a marked calibration curve to obtain the concentration of melamine in the extracting solution, thus obtaining the concentration of the melamine in the sample to be detected, wherein detection conditions of the ion chromatograph are that the sample size is 20 mu L, leacheate is an aqueous solution of sulfuric acid at the concentration of 1.5mmol/L, the flow rate is 0.9mL/min and the detection wavelength of an ultraviolet detector is 240nm. Compared with the prior art, the method has the advantages that: the melamine content in multiple samples can be effectively detected, the whole operation is simple and quick, the detected melamine content is accurate, and a blank of detecting the melamine content in multiple samples by the ion chromatography is filled up.

The invention discloses a fast detecting method for sulfonamide residues in shrimps. Methyl alcohol is used for extracting the sulfonamide residues in shrimp mince, stable fuchsia derivatives are formed through a fast derivation reaction of the sulfonamide residues and a specific derivatization reagent, a color development result is observed through the naked eyes so that fast detection can be achieved, and the detection sensitivity can reach 50 microgram per kilogram at least. The fast detection method is simple in pretreatment, short in detection time and low in detection cost, a large instrument is not needed, field detection can be achieved, color changes are observed through the naked eyes so that the detection result can be rapidly obtained, and the sulfonamide residues in the shrimps can be rapidly and efficiently detected.

The invention discloses a method for measuring the content of lactoferrin in infant milk powder, which comprises the following steps: adding to-be-measured infant milk powder into a phosphate buffer solution A to completely dissolve the infant milk powder, and adjusting the pH value to be acidic to form casein precipitate to obtain a mixed solution; centrifugally separating the mixed solution, taking supernate, and adding the phosphate buffer solution A to obtain a sample injection solution; and taking the sample injection solution, and detecting the sample injection solution in high performance liquid chromatography, wherein a chromatographic column of the high performance liquid chromatography is a heparin affinity column. According to the method, impurity proteins in the infant milk powder are precipitated by adjusting the pH value, then a high performance liquid chromatograph (the chromatographic column is a HiTrapTMHeparin HP (1mL) heparin affinity column) is directly used for determination, and a target object is extracted through buffer salt. According to the method, the pretreatment steps are optimized, and the heparin affinity column is used for determination, so that the method is simple, and the detection efficiency is high.

The invention discloses a method for analyzing protein adulteration in dairy products. The method comprises the following steps of: dividing a sample into two parts, performing alkaline hydrolysis on one part of the sample, and performing acidolysis on the other part of the sample; neutralizing by using acid after alkaline hydrolysis, drying by distillation after acidolysis, redissolving by using dilute acid, derivatizing the redissolved liquid by using derivating agents, and filtering by using an organic filter membrane so as to obtain sample liquor; respectively preparing a tryptophan standard solution and a mixed standard solution of threonine, valine and lysine; and respectively injecting the standard solutions and the sample liquor into a high performance liquid chromatograph, then measuring the peak area of the standard solutions and the peak area of the sample liquor, and calculating the content of the tryptophan, the threonine, the valine and the lysine in the sample liquor. The method is simple in operation, low in analysis cost and easy to popularize and apply, and an analysis result can be obtained quickly.