37results about How to "High linear correlation" patented technology

The invention discloses a detection method and detection device for ctDNA (circulating tumor DNA) proportion based on capture sequencing. The detection method includes the following steps: S1, obtaining baseline sample DNA and gene data of capture sequencing of cfDNA (circulating cell-free DNA) to be tested; S2, using the homozygous and heterozygous sites in the baseline sample DNA at the same time, and selecting the sites on which the mutation frequency between the baseline sample DNA and the cfDNA to be tested is significantly different and the predetermined filtering conditions are satisfied as candidate SNP (Single Nucleotide Polymorphisms) sites; S3, determining a mutation type of the candidate SNP sites of normal cell DNA and ctDNA, in combination with the situation that copy numbervariation occurs in the region where the candidate SNP sites are located; and S4, establishing a probability model by using a maximum likelihood method, and obtaining ctDNA proportion by calculation through the probability model. The application of the technical scheme of the detection method and detection device for ctDNA proportion based on capture sequencing can improve the sensitivity and accuracy of CNV (copy number variation) detection of plasma ctDNA at the same time from various aspects.

The invention discloses a method for simultaneously detecting 26 organic acids and inorganic negative ions in juice and a juice manufacturing method. According to the method, a juice sample is preprocessed; multilevel-inhibition conductance ion chromatography is utilize to simultaneously detect 18 organic acids (quinic acid, lactic acid, propionic acid, formic acid, butyric acid, pyruvic acid, pentanoic acid, acetic acid, malonic acid, malic acid, citric acid, glutaric acid, maleic acid, fumaric acid, benzoic acid, cis-aconitic acid, trans-aconitic acid, and oxalic acid) and 8 inorganic negative ions (F<->, Cl<->, NO3<->, NO2<->, ClO2<->,BrO3<->, PO4<3->, and CrO4<2->) in a juice; the sample pretreatment is simple, rapid and accurate; the technical problem that multiple components in juice cannot be accurately analyzed is solved, organic acids and inorganic negative ions in juice can be accurately measured, a technical support is provided for judging nutritional value, freshness degree, and true/false of juice, and the components of juice can be detected by the method.

The invention relates to a preparation method of a metalloporphyrin oxygen sensing film. According to the preparation method, the problems that after a phosphorescent reagent is embedded in an oxygen sensing film prepared by virtue of existing methods, the sensitivity is low, the response time is long, and the phosphorescent reagent is easily optically degraded and is low in linear fitting are solved. According to the preparation method, the oxygen sensing film is prepared by taking octaethyl porphilin platinum as an indicator, methyl methacrylate and trifluoroethyl methacrylate as copolymer matrixes, tributyl phosphate as a plasticizer and an azodiisobutyronitrile toluene solution as an initiator. The preparation method is used for preparing the metalloporphyrin oxygen sensing film.

Provided is a method for measuring free chlorine and total chlorine in water. Measuring steps are simple, the volume of a water sample is reduced to 1/10 of the original volume, and the sample taking amount is reduced; the sampling taking volume does not need to be precise and quantitative, and errors caused when sampling is not accurate are eliminated; the measuring range is widened, and linear dependence and sensitivity are improved. A reagent is convenient to store and long in storage time.

The invention discloses a preparation method of a ratio oxygen sensing film for detecting the contents of dissolved oxygen, relates to the preparation method of the ratio oxygen sensing film, and aimsat solving the problem that the existing ratio oxygen sensing methods are high in cost and bad in photo-bleaching resistance due to the reason that to-be-tested water samples are polluted and cannotbe recovered. The method comprises the steps of 1, uniformly dispersing azobisisobutyronitrile solution in St/TFEMA mixed solution, copolymerizing the mixed solution under nitrogen protection to obtain copolymer solution, and carrying washing and suction filtration; 2, mixing PtOEP/toluene solution with C6/toluene solution to obtain mixed indicator solution, re-dissolving the copolymer solution intoluene to obtain copolymer/toluene solution, mixing the copolymer/toluene solution with the mixed indicator solution, applying the obtained mixed solution on a quartz plate, and carrying out dryingto obtain the ratio oxygen sensing film. The ratio oxygen sensing film can be recycled for multiple times, has no pollution to the environment, and has photo-bleaching resistance. The method is used in the field of dissolved oxygen detection.

The invention discloses a method for testing a fluorescence signal of oxygen concentration in water by an enhancing oxygen sensitive film. The method comprises the following steps: 1) dissolving polystyrene powder into toluene to form a transparent solution; adding PtTFPP (Platinum Tetrakis(pentafluorophenyl) Porphyrin) into the transparent solution to form an oxygen-sensitive solution; 2) coatinga substrate with the oxygen-sensitive solution and carrying out thermosetting to obtain an oxygen-sensitive film; 3) dissolving ethyl orthosilicate and dimethyldimethoxysilane into ethanol and stirring; after adding water and hydrochloric acid and stirring, adding carbon black or barium sulfate powder to form black or milk white turbid liquid; 4) taking acetic acid as a solvent and dissolving cellulose acetate to form a solution; adding the carbon black or barium sulfate powder to form black or milk white turbid liquid; 5) taking the acetic acid as a solvent and dissolving the cellulose acetate to form a solution; adding water into the solution to obtain a transparent solution; 6) wetting the oxygen-sensitive film prepared by step 2) into the solutions of steps 3), 4) and 5) in a dip-coating manner; taking out the oxygen-sensitive film and carrying out the thermosetting to obtain a composite sensing film.

The invention discloses an enzyme-free glucose sensor, a preparation method thereof, and a glucose concentration testing system composed of the sensor. The enzyme-free glucose sensor comprises a glassy carbon electrode as a substrate, a PS film deposited on the glassy carbon electrode and Pd-Ce particles adsorbed on the glassy carbon electrode. The preparation method of the enzyme-free glucose sensor comprises (10) glassy carbon electrode pretreatment; (20) deposition of PS film; (30) Pd-Ce(PS)-GC electrode preparation steps. Glucose concentration test system comprises working electrode, auxiliary electrode and counter electrode, and described counter electrode is a platinum sheet electrode, and auxiliary electrode is saturated calomel electrode, and described working electrode is based on Pd-Ce(PS)-GC enzyme-free glucose sensor . The non-enzyme glucose sensor and the glucose concentration test system composed of the present invention have good selectivity and high sensitivity.

The invention provides an analytical kit for detecting four free fatty acids (alpha-octadecatrienoic acid, eicosapentaenoic acid, omega3-docosapentaenoic acid and docosahexaenoic acid) in human bloodspots through high performance liquid chromatography-tandem mass spectrometry. The analytical kit specifically comprises replacement matrix pretreatment, dried blood spot sample treatment and the like. The method has the advantages of high sensitivity, short time and improved detection efficiency.

The invention discloses a method for determining escape ammonia in flue gas of a cement plant. The method comprises the following steps: introducing flue gas of the cement plant into absorption liquid, and performing constant volume treatment with water, thus obtaining to-be-determined solution; preparing standard curve solution; respectively placing the to-be-determined solution and the standardcurve solution into different colorimetric tubes provided with a plug, performing constant volume treatment with water, then sequentially and respectively adding salicylic acid-trisodium citrate solution, sodium nitroprusside solution and sodium hypochlorite solution into the colorimetric tubes provided with the plug and uniformly mixing, then stabilizing the colorimetric tubes provided with the plug for 2-4 hours at the temperature of 30-40 DEG C, and then performing colorimetric determination according to coloring depth, thus obtaining concentration of ammonia in the flue gas of the cement plant. The method disclosed by the invention determines ammonia concentration by utilizing an indophenol blue spectrophotometric method, the help of large-scale analytical instruments and equipment isnot required as the detection analysis method is adopted, and the method is simple, quick and accurate, saves cost, has obvious practicability and is applicable to field laboratory analysis; and detection results are stable, repeatability is good, detection accuracy and precision are improved, and a measurable concentration range of a sample is broadened.

The invention provides a determining method of COD of paper waste water. The method includes following steps: (1) determining an ultraviolet maximum absorption wavelength of to-be-tested paper waste water; (2) drawing a correlation curve of (A maximum absorption wavelength - A546) absorbance to the COD; and (3) preparing to-be-tested paper waste water again, and determining the COD of the to-be-tested paper waste water according to the A maximum absorption wavelength of the absorbance under the ultraviolet maximum absorption wavelength of the to-be-tested paper waste water and the absorbance value A546 under an 546 nm visible light wavelength and according to the correlation curve drawn in the step (2). The determining method is simple in operation, is free of a large amount of repeatability test processes, is reduced in determining time and is free of secondary pollution caused by usage of chemical reagents for detection.

The invention relates to a linearization method based on piecewise curve fitting, the method comprising the following steps: step 1) recording the relationship between the input power and the output power of the power amplifier through testing the actual power amplifier; step 2) on a MATLAB platform, establishing a power amplify model based on the recorded power amplify data, and carrying out predistortion simulation through an indirect predistortion module based on the power amplifier model; step 3) on that basis of the predistortion simulation, replacing the common LS algorithm with the LS adaptive algorithm optimize by the segmentation processing for further simulation. The beneficial effects are: there is a higher linear correlation between input and output than the general method of using series to achieve predistortion. Through adoption of the idealized straight line, the maximum error is reduced from 0.05 V to 0.01 V, and the precision grade is increased to 5 times of the original value.

An embodiment of the invention discloses a method for generating vehicle straight driving direction indications. The method comprises: determining whether a driving state of a vehicle is a straight driving state; when the driving state of the vehicle is the straight driving state, obtaining a plurality of three-dimensional coordinates output by a three-axis acceleration sensor of the vehicle in preset duration and caching; according to the plurality of three-dimensional coordinates output by the three-axis acceleration sensor, generating a straight line indicating a vehicle straight driving direction. An embodiment of the invention also discloses a device for generating vehicle straight driving direction indications. The method and the device make linear dependency of acquired points high, so as to accurately determine the straight direction of vehicle driving, and reduce errors.

The invention discloses a measurement method for chromium VI in water. A diphenylcarbazide spectrophotometric method is used for measuring the chromium VI in water. The whole method has simple measurement steps; reagent can be conveniently stored and has a long storage period, water sample volume is reduced to 1/5 of the original volume, a sampling amount is reduced, the water sample volume does not need to be accurately quantified, errors generated due to inaccurate sampling are eliminated, a measurement range and linear correlation are improved, and sensitivity and anti-interference performance are improved.

The invention relates to a method and device for predicting the viscosity of base oil. The method comprises the following steps that: the near infrared spectrum of to-be-detected base oil is acquired;the near-infrared spectrum in a preset wave number range is inputted into a preset model, so that the viscosity mixing index of the to-be-detected base oil is obtained, wherein the preset model represents a corresponding relationship between the near-infrared spectrum of the base oil and the viscosity mixing index; and the viscosity of the base oil is calculated according to the viscosity mixingindex and a preset function. A linear correlation between the viscosity mixing index obtained after the conversion of the preset function and the near infrared spectrum is higher that a linear correlation between viscosity and the near infrared spectrum, and therefore, by means of the conversion between the viscosity and the viscosity mixing index by the preset function, the problems of the instability and inaccurate prediction of a model which is established on the basis of a multiple regression analysis method and is used for representing a corresponding relationship between a near infraredspectrum and viscosity due to excessive nonlinear information between the near infrared spectrum and the viscosity property of base oil can be solved.

The invention discloses a rapid cell classification and quantification method based on a coffee ring and belongs to the field of cell detection. The key point of the invention is to provide an LIBS signal acquisition method of a cell suspension coffee ring, which mainly comprises the following steps of dropwise adding a cell suspension to a monocrystalline silicon wafer, naturally drying to form a coffee ring, and then carrying out LIBS signal acquisition on endogenous characteristic elements of cells in a coffee ring area. The invention further provides a method for constructing the cell characteristic annular imprinting fingerprint element atlas database and the corresponding cell characteristic annular imprinting fingerprint element atlas database. The invention also provides a cell classification method which is used for realizing cell classification by comparing the sample annular mark fingerprint element atlas with the atlas database. The invention also provides a cell quantification method based on the LIBS signal acquisition method of the cell suspension coffee ring. The method realizes quantification based on the linear relationship between a spectral line intensity value and the cell concentration in the LIBS signal.

The invention provides an improved fountain landscape sound box. The improved fountain landscape sound box comprises a base, a motor, a water pump and a water tank; a first power amplification module is arranged in the base and outputted to a loudspeaker; the first power amplification module is synchronously outputted to a current processing chip for treating inputted current by extraction of square root; the current processing chip is outputted to a second power amplification module which is outputted to the motor; the motor drives the water pump; the water pump drives water in the water tank to upwards flow through injection holes to form fountain torrent. The sound box includes a music fountain; the fluctuating of the fountain torrent is in linear relation with the music.

The invention provides a method for determining four free fatty acids (alpha-octadecatrienoic acid, eicosapentaenoic acid, omega3-docosapentaenoic acid and docosahexaenoic acid) in human dried blood spots by using a high performance liquid chromatography tandem mass spectrometry hyphenated technique. The method comprises the steps that four free fatty acids are separated by high performance liquidchromatography; mass spectrometry isotope internal standard quantitation is used; the concentration of the standard is taken as the X-axis, and the peak area ratio of the standard to the internal standard is the Y-axis to establish a calibration curve; and the content of the four free acids in human dried blood spots is calculated. The method provided by the invention has the advantages of high sensitivity, high specificity, accuracy, simple pretreatment process, short time and improved detection efficiency.