12 results about "Relative standard deviation" patented technology

The application belongs to the technical field of analysis and detection, and provides a method for detecting residual polydimethylsiloxane content in engineering bacteria-derived cytidine 5'-diphosphocholine sodium by using ultraviolet-visible spectrophotometry. The detection method provided by the application is mainly based on the coordination reaction of polydimethylsiloxane and chromogenic solution, and uses ultraviolet-visible spectrophotometry to detect the absorbance value of the blue complex product at 621 nm. The detection method solves the problem of high cost of high-end instrument detection, and has the characteristics of high sensitivity, good repeatability and accuracy. Relevant data shows that the relative standard deviation is less than 2.0%, the recovery rate is in the range of 80% to 120%, and RSD is less than or equal to 2%.

The application discloses a method for simultaneously detecting 59 kinds of halogenated phenolic and quinone disinfection by-products based on solid phase extraction enrichment and high performance liquid chromatography mass spectrometry, and belongs to the technical field of disinfection by-product detection. The method comprises the following steps: 1, drawing standard curves of 59 kinds of halogenated phenolic and quinone disinfection by-products respectively; and 2, quantitatively analyzing the concentration of halogenated phenolic and quinone disinfection by-products in a water sample to be detected. The application can simultaneously detect 59 kinds of halogenated phenolic and quinone DBPs, and the detection limit and the quantitative limit are 0.03 ng / L to 135.23 ng / L and 0.1 ng / L to 450.76 ng / L respectively; the recovery rate and the relative standard deviation (RSD) of the river water are 72.41% to 119.54% and 1.86% to 16.03% respectively; and the recovery rate and the RSD of the tap water in Harbin are 83.52% to 122.36% and 2.09% to 14.95% respectively.

This invention relates to the field of electronic digital data processing technology and discloses a method for generating structural parameters of a static mixer. The method includes: selecting the inclination angle of the crossbars and the aspect ratio of the mixer as structural parameters to be optimized, with the optimization objectives being minimizing the relative standard deviation of the concentrations of each component at the outlet section and minimizing the pressure drop; constructing a three-dimensional geometric model of the static mixer based on the structural parameters and setting the inlet and outlet positions; solving the flow field based on the Navier-Stokes equations and the continuity equation, and solving the concentration field of each component based on the convection-diffusion equation; obtaining the concentration distribution and pressure drop data of each component at the mixer outlet section under different structural parameters through multiphysics simulation, and calculating the relative standard deviation of each component concentration; screening structural parameter combinations with relative standard deviations less than a threshold, and selecting the one with the smallest pressure drop as the optimal structural parameter. This method solves the problems of reliance on trial and error and long cycles, achieving the goals of high accuracy, high efficiency, and low cost.

The application discloses an integrated analysis method for high-coverage detection and multi-reaction monitoring accurate quantification of small molecule compounds in complex samples, which utilizes high performance liquid chromatography-mass spectrometry technology, adopts Zeno SWATH technology, effectively collects mass spectrometry information of low-abundance small molecules, and utilizes MSDIAL to search a database with collected mass spectrometry data to annotate small molecule compounds in complex samples; meanwhile, high resolution-multi-reaction monitoring (HR-MRM) mode is combined to realize synchronous analysis of high-coverage detection and accurate quantification of small molecule compounds in vivo. The method performs excellently in terms of intra-day / inter-day precision and repeatability, more than 90% of characteristics have relative standard deviation (RSD) less than 20%, and the RSD of intra-day / inter-day precision, repeatability and recovery rate of all targeted analysis target objects is less than 20%; the high-throughput method not only significantly saves experimental and data processing time, but also avoids systematic errors of multi-platform data integration, and provides a new paradigm for non-targeting-targeting integrated analysis.

The application belongs to the technical field of CO2 flooding, and discloses a method for testing low-permeability sandstone core saturation for CO2 flooding, which comprises the following steps: selecting a rock sample; treating the rock sample; measuring the effective porosity and density of the rock sample; selecting divinylbenzene and styrene as a carrier; using phthalate as a stationary phase, coating the stationary phase on the surface of the carrier to prepare a special saturation analysis chromatographic column, and selecting a chromatographic column with an inner diameter of 4 mm and a length of 2.2 m made of stainless steel; using an organic solvent cleaning method + a hot cleaning method to treat and maintain the contaminated detector; and using a combination of a standard curve method and a normalization method to calculate the instantaneous peak area and the total peak area. After the application of the new method, the measurement accuracy is higher, the various deviation calculations and mathematical statistics values are smaller, the relative standard deviation of the new method is less than or equal to 2.5%, the recovery rate is more than 97.5%, the technical quality and the measurement accuracy are doubled, the dosage of the medicament and the emission of toxic substances are reduced, and the work efficiency and the analysis efficiency are improved.

This invention belongs to the field of metal composition analysis technology and discloses a method for determining ultra-low carbon and sulfur content in high-purity nickel. This method addresses the problems of matrix mismatch and insufficient detection range in existing detection methods by achieving accurate determination through the following steps: 1. Pre-treating the high-purity nickel sample using acetone ultrasonication and hydrochloric acid immersion to remove surface impurities; 2. Preparing a series of reference reagent standard samples using sucrose and sulfate standard solutions to adapt to the high-purity nickel matrix; 3. Constructing a standard curve with dual calibration of solid standard samples and reference reagents, extending the detection range to 0.0005%~0.005% for carbon and 0.0001%~0.002% for sulfur; 4. Subtracting interference through blank experiments and calculating the carbon and sulfur content in the sample according to the formula. The carbon and sulfur spiked recoveries of this invention are 95%~103% and 96%~102%, respectively, with relative standard deviations of <13.2% and <22.0%, respectively. It features fast analysis speed, high accuracy, and traceable results, and is suitable for the detection of ultra-low carbon and sulfur content in high-purity nickel and similar metal materials.

This invention discloses a rapid method for detecting the purity of industrial-grade lanthanum oxide using boric acid as a binder, belonging to the field of material purity testing technology. The method involves sampling and mixing samples at a frequency of one batch per trip. The sample is ground to a particle size ≤100μm, then mixed with boric acid at a mass ratio of 1:1-3:1, dried, and filled into a 40mm diameter mold. One to three parallel samples are prepared by pressing under a pressure of 5-30MPa and a holding time of 15-45s, and then sealed and allowed to stand for 1-6 hours. Simultaneously, a lanthanum oxide standard sample with a purity of 90.0%-99.9% is prepared using the same proportion and method. The standard and sample are detected using an X-ray fluorescence spectrometer with a resolution ≤0.1keV, with the La Kα1 characteristic spectral line channel set. The actual purity of the sample is calculated using a standard correction factor. When the relative deviation of the parallel samples is ≤0.5%, the average value is taken as the final result. This invention solves the problems of long detection cycles, low accuracy, and complex operation of traditional methods, reducing the detection cycle to ≤1.5 days. Within hours, the relative standard deviation of the test results is ≤0.30%, and the operation threshold is low.

The application provides a liquid chromatography-mass spectrometry method capable of efficiently detecting deoxynivalenol (DON) acetylated derivative: 3-acetyldeoxynivalenol (3-Ac-DON). The detection method detects 3-Ac-DON in a negative ion mode, and compared with a conventional positive ion detection scheme, the detection limit of the method is 8 ppb (10 ppb according to the national standard), and the sensitivity is higher; by using high-resolution mass spectrometry and an optimized negative ion system, the anti-matrix interference ability and the qualitative accuracy are significantly improved, and meanwhile, the method has good linearity and precision, and is suitable for accurate detection of 3-Ac-DON in various samples. The detection time of the application is 10 min, the retention time of 3-Ac-DON is 8.41 min, the detection limit is 8 ng / ml, the quantification limit is 20 ng / ml, the linear range is 20-2000 ng / ml, the correlation coefficient R 2 =0.9995, and the relative standard deviation RSD is 1.25%.

This invention belongs to the field of molecular biology technology, specifically relating to primer-probe combinations, kits, detection methods, and applications for detecting residual DNA from *Bacillus polymyxa* in polymyxin raw materials. The primer-probe combination for detecting residual DNA from *Bacillus polymyxa* in polymyxin raw materials of this invention comprises: a forward primer, the sequence of which is shown in SEQ ID NO: 1; a reverse primer, the sequence of which is shown in SEQ ID NO: 2; and a probe, the sequence of which is shown in SEQ ID NO: 3. This invention has the following technical advantages: 1) The qPCR detection method of this invention has a linear range of 3 fg / μL to 300 pg / μL for the DNA standard solution, and a correlation coefficient R0. 2 >0.99, slope of -3.1 to -3.8, LOD equivalent to 75 pg / g, recovery rate of quality control samples of 50% to 150%, relative standard deviation (RSD) of test samples of less than 30%, and all parameters of method validation meet the requirements. 2) It can easily, quickly and accurately quantify residual DNA in polymyxin raw materials.

The application discloses a kind of tobacco hygroscopicity characterization method, belong to tobacco processing and storage technical field, comprising the following steps: S1, sample preparation;S2, experimental condition setting;S3, dynamic moisture absorption monitoring;S4, multi-parameter calculation;S5, moisture absorption isotherm fitting;S6, temperature sensitivity analysis;S7, result verification and characterization: the repeatability of data is verified by parallel experiment, and output moisture absorption kinetics curve, moisture absorption isotherm and characteristic parameter report.The application can completely describe the "static balance-dynamic process-environment response" characteristics of tobacco hygroscopicity by constructing the multidimensional parameter system of "moisture absorption amount-moisture absorption rate-diffusion capacity-humidity sensitivity", solve the problem of single parameter in traditional method, clear sample pretreatment, humidity control precision, humidity and monitoring interval, ensure that experimental data of different laboratories and different batches are comparable, solve the problem of poor repeatability of traditional method, and reduce the relative standard deviation of data.

The present invention relates to a physical information-based artificial intelligence device and a prediction model training method therefor, the device being capable of reducing training time and increasing prediction accuracy of a prediction model for predicting experimental results of a product, and comprising: a database for storing a dataset including a physical information function; and a processor for generating a prediction model that predicts experimental results of a product on the basis of the dataset, wherein the processor can: acquire, for each pre-selected initial design of experiment (DOE), a first dataset including a physical information function; train a neural network model to predict experimental results of a product by inputting the first dataset to the neural network model; select, on the basis of the training result, DOEs having an accuracy lower than a first reference value from among initial DOEs; extract, for each selected DOE, a design factor having a relative standard deviation (RSD) lower than a second reference value; acquire, for each new DOE including the extracted design factor, a second dataset including a physical information function; retrain the neural network model on the basis of the second dataset; and generate a prediction model on the basis of the retrained neural network model when the retraining result reaches a target error.

This invention discloses a method and apparatus for detecting impurity elements in organic solutions, belonging to the field of component detection technology. The apparatus includes an ICP system, a sample introduction system, and a spectroscopic analysis unit. The ICP system has a three-layer concentric rectangular tube structure, with an enlarged inner diameter and a narrowed opening in the central tube, and the inner wall coated with yttrium oxide. The outer and middle tubes form independent cooling and auxiliary gas channels. The sample introduction system includes a temperature-controlled nebulizer chamber and a three-way mixing valve. The spectroscopic analysis unit uses a two-point background correction method to process the signal. The method uses a 1.6-1.8 kW gradient power to excite and create an online micro-oxidation environment, acquires the signal, performs two-point background correction, and calculates the concentration using a matrix-matched calibration curve. This invention achieves continuous and stable plasma operation with no significant carbon buildup, and the relative standard deviation of continuous measurements is <3%, making it suitable for batch detection of various organic solutions.