38results 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 relates to the technical field of veterinary drug residue detection, in particular to a method for analyzing residual antibiotics in beef. The method at least comprises the steps that beef samples are subjected to pretreatment, extraction, purification and monitoring analysis, wherein the monitoring analysis is conducted by means of a chromatogram-mass spectrometry combined technology. In the extraction process, a surfactant is adopted for increasing a dissolution rate of the target antibiotics; in the purification process, a demulsifier is adopted for reducing an emulsificationrate of a system, matrices and other impurities are precipitated and removed, and the precision and sensitivity of the detection process are further improved.

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 a method capable of realizing high throughput detection of total germ genomic DNA content mbac, genomic DNA content mi of each microorganism species, the copy number of genomicDNA of each microorganism species Ni and the cell population Ui of each microorganism species in a to-be-detected sample. By detecting a test sample by virtue of the method provided by the inventionand a qPCR method, the detected mass concentrations of the microorganism species have extremely high linear correlation under conditions of different microorganism constitutions and different microorganism nucleic acid proportions, and a detection result shows that the method provided by the invention has relatively high accuracy. According to the method, results, obtained by virtue of clinical pathogenic microorganism metagenome NGS detection method, of different samples are comparable, and traditional clinical pathogenic microorganism metagenome NGS detection is improved from a qualitative detection method to a quantitative detection method, so that the method provided by the invention has important application values.

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.

The invention discloses a preparation method of a high-sensitivity self-cleaning type blood oxygen sensor based on photonic crystal fluorescence enhancement, and relates to the field of a fluorescent oxygen sensor, in particular to a preparation method of a blood oxygen sensor based on photonic crystal fluorescence enhancement. The invention is to solve the problems of leakage of an indicator and weakened fluorescence signal when a blood oxygen sensor prepared through an existing method is used for blood oxygen detection. The method comprises the steps of: 1, placing polystyrene microsphere emulsion in a light resistant container, adding a fluorescent dye, carrying out ultrasonic treatment, swelling in a dark box at the room temperature, carrying out centrifugation, and re-dispersing precipitates with pure water to obtain dispersed microsphere emulsion; and 2, adding polysorbate solution into the microsphere emulsion, carrying out ultrasonic treatment, and putting into a flat-bottomed glass tube; obliquely putting a quartz plate into the flat-bottomed glass tube, and putting the flat-bottomed glass tube and the quartz plate into a waterproof incubator together until the emulsion is completely evaporated, so as to obtain a photonic crystal device; and spin-coating a layer of PDMS on the surface of the prepared photonic crystal device, and curing to obtain the blood oxygen sensor. The invention is applied to the field of the sensor.

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 relates to the technical field of veterinary drug residue detection, in particular to a method for analyzing residual antibiotics in beef. The method at least comprises the steps that beef samples are subjected to pretreatment, extraction, purification and monitoring analysis, wherein the monitoring analysis is conducted by means of a chromatogram-mass spectrometry combined technology. In the extraction process, a surfactant is adopted for increasing a dissolution rate of the target antibiotics; in the purification process, a demulsifier is adopted for reducing an emulsificationrate of a system, matrices and other impurities are precipitated and removed, and the precision and sensitivity of the detection process are further improved.

The invention relates to a method for predicting the crude oil viscosity through nuclear magnetic resonance spectrums. The method comprises: (1) taking different types of crude oil samples, and determining the viscosity value by using a standard method; (2) determining the nuclear magnetic resonance hydrogen spectrums of each crude oil sample, carrying out a first order differentiation treatment on the spectrums, taking the peak intensities in the spectrum zones with chemical shifts of 5.5-8.5 ppm and 1.0-3.7 ppm to associate with the logarithms of the corresponding viscosities determined by using the standard method, and establishing a correcting model through a partial least square method; and (3) determining the nuclear magnetic resonance hydrogen spectrum of the crude oil sample to be determined, carrying out the first order differentiation treatment on the spectrums, taking the peak intensities in the spectrum zones with chemical shifts of 5.5-8.5 ppm and 1.0-3.7 ppm to substitute into the correcting model so as to obtain the viscosity logarithm value of the crude oil sample to be determined, and then converting into the viscosity. With the method, the crude oil viscosity can be predicted through the nuclear magnetic resonance spectrum of the crude oil sample and the correcting model having the liner correlation can be established, and the method has characteristics of rapid analysis, accurate test, and easy operation.

The invention discloses a preparation method of a binary copolymerization fluorescent microsphere emulsion for measuring the dissolved oxygen concentration, relates to a preparation method of the binary copolymerization fluorescent microsphere emulsion, and aims to solve the problems that the conventional indicator molecules are easy to leak, poor in stability, not high in sensitivity to oxygen and poor in dispersivity, and solvents used in the conventional method is not environment-friendly. The preparation method comprises the following steps: mixing methyl methacrylate and trifluoroethyl methacrylate to obtain a copolymer emulsion; then, adding platinum octaethylporphyrin into the copolymer emulsion, mixing uniformly, then, adding azodiisobutyronitrile and lauryl sodium sulfate, stirring under the conditions that the temperature is 35-45 DEG C and the rotating speed is 250-300 r / min, adding ultrapure water, performing ultrasonic treatment at the room temperature and with the ultrasonic frequency of 20-45 kHz, and performing reflux reaction at the temperature of 60-70 DEG C, so as to obtain the binary copolymerization fluorescent microsphere emulsion.

The application of the ratio oxygen sensing film in temperature detection relates to the application of a ratio oxygen sensing film. It is to solve the problems that the existing temperature measuring materials are seriously interfered by the change of the external atmosphere and have low sensitivity. Ratiometric oxygen sensing membranes are used for temperature detection. The ratio oxygen sensing film is not disturbed by the change of external oxygen during the temperature detection process. The ratiometric oxygen sensing film has a strong response ability to temperature and high sensitivity, and is suitable for accurate detection in the temperature range (32-60°C). The invention is applied to the field of temperature detection.

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.

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 relates to the field of food detection, in particular to a method for detecting residue of veterinary drugs in aquatic products. The method provided by the invention is used for detecting the residual veterinary drugs in the aquatic products. Compared with the existing detection methods, the method has higher accuracy, can simultaneously extract, purify and test the various veterinary drugs, and is fast and efficient. The method provided by the invention adopts a terbium-doped lipid adsorbent, can absorb the residual grease in the aquatic products during the extraction of the veterinary drugs, reduces the influence of the grease on the detection of the veterinary drugs, and improves the accuracy, sensitivity and precision of the detection. The analytical method provided by the invention has very high linear correlation, accuracy and purification effect, and is lower in detection limit and limit of quantitation.

The invention relates to the field of analysis and testing and particularly relates to a method for analyzing residual veterinary drugs in mutton. The method at least comprises sample pretreatment, enzymatic hydrolysis, extraction, purification and on-machine testing. Compared with the existing detection method, the method provided by the invention has higher accuracy, extracts, purifies and testsa variety of veterinary drugs, and is fast and efficient. The method utilizes a multi-extraction method using three different solvents, fully extracts the veterinary drugs in mutton as many as possible, improves the detection accuracy and reduces the influence caused by the base on the veterinary drugs. In gradient elution, three mobile phases are used so that it is solved that the original two mobile phases with solubility under action of an adsorbent in a chromatographic column are layered so that the target drugs are respectively dissolved in two solvents, the characteristic peak detectedby the detector splits into a primary characteristic peak and a secondary characteristic peak, the drug content capable of being detected is reduced and the determination of other drugs is influenced.

The invention relates to an adaptive tracking elastic sensor for welding grooves, which is composed of an upper tracking seat and a lower tracking seat; each of the two tracking seats includes a tracking seat body, a four-hinge connecting rod mechanism, a piston assembly, and a detection roller ;The four-hinge linkage mechanism includes a connecting rod, a static hinge shaft, and a dynamic hinge shaft. The other two opposite hinge shafts are also the shafts of the detection rollers on the side of the welding groove; The seat body is a whole; the piston rod is movably connected with the dynamic hinge shaft, and the static hinge shaft is movably connected with the inner side of the other end of the tracking seat body. The advantages of the present invention are: two sets of elastic sensors are symmetrically installed and used, which can simultaneously save the mechanical displacement amount-power conversion, deviation signal identification, calculation of control adjustment amount, and multiple process control links of electric adjustment, and there is no need to establish a mathematical model; Complete the three-dimensional direction of the welding groove and self-adaptive centering at the same time; the system error is small, the manufacturing difficulty is low, the balance of the force system is easy to adjust, and the tracking dimension is high.