7 results about "Ultraviolet absorption spectrum" patented technology

This invention discloses a method for detecting polycyclic aromatic hydrocarbons (PAHs) based on ultraviolet fluorescence and absorption spectroscopy, comprising: Step 1, acquiring the ultraviolet absorption spectrum and the fluorescence emission spectrum of a water sample under ultraviolet light excitation; Step 2, analyzing the corresponding CDOM fluorescence spectrum using the ultraviolet absorption spectrum obtained in Step 1; Step 3, subtracting the CDOM fluorescence spectrum obtained in Step 2 from the fluorescence emission spectrum obtained in Step 1 to obtain a mixed fluorescence spectrum containing multiple PAHs; Step 4, performing multivariate fitting on the mixed fluorescence spectrum obtained in Step 3 to obtain the type and concentration of each PAH in the water sample. This invention also provides a PAH detection device. The method provided by this invention is simple to operate and can directly detect raw water samples, thereby obtaining more accurate PAH detection results.

The application discloses a sunscreen composition based on the ultraviolet absorption characteristics of yellow water of liquor, and a preparation method and application thereof. The sunscreen composition comprises 10-60 parts by weight of a yellow water extract of a strong-flavor liquor, 20-70 parts by weight of a yellow water extract of a Maotai-flavor liquor, and 0-40 parts by weight of a yellow water extract of a light-flavor liquor. It is found that the yellow water of different flavor liquors has characteristic ultraviolet absorption spectrum, wherein the yellow water of the strong-flavor liquor has strong absorption in the UVB band (290-320 nm), the yellow water of the Maotai-flavor liquor has strong absorption in the UVA band (340-380 nm), and the yellow water of the light-flavor liquor has relatively uniform absorption in a wide band. According to the spectral complementarity, the natural sunscreen composition is obtained. The sunscreen composition has an in-vitro SPF value of 15-35, a PA value of ++~++++, good light stability and low skin irritation.

This invention discloses a method for identifying fresh / dried cocoon raw silk based on ultraviolet absorption spectroscopy. The method includes: pre-treating and extracting raw silk samples from fresh and dried cocoons to obtain a test solution; collecting the ultraviolet absorption spectra of the test solution and ultrapure water, and obtaining a corrected ultraviolet absorption spectrum after background signal correction; pre-processing the corrected ultraviolet absorption spectrum to obtain a pre-processed spectrum and its derivative spectrum; performing difference analysis to screen difference scoring indicators, and then establishing a discrimination model for fresh and dried cocoons; obtaining the pre-processed spectrum and its derivative spectrum of the raw silk sample to be identified, inputting them into the discrimination model for processing, and outputting the category to complete the identification of fresh and dried cocoon raw silk. This invention is convenient to operate, uses relatively common instruments, has high accuracy, and the accuracy can be further improved with increasing sample size, making it easy to promote and apply, and meeting the needs of identifying fresh / dried cocoon raw silk.

This application relates to a method for constructing an LCMS reading model and the application of the LCMS reading model. The construction method includes: acquiring LCMS training data, which includes training samples and corresponding training labels; wherein, the training samples include at least one of material structure features, mass spectrum features, ultraviolet absorption spectrum (UV) features, MS-UV correlation features, and instrument parameter features; the training labels include reading results corresponding to at least one business type; and iteratively training the initial model based on the LCMS training data to obtain a trained LCMS reading model, which is used to predict the target reading results corresponding to the business type. The solution provided in this application can efficiently and accurately output reading results for different business types, providing a reliable guarantee for the automated preparation process of products.

This invention relates to spectroscopic technology, specifically providing a method for oil analysis in water based on the fusion of ultraviolet absorption spectroscopy and three-dimensional fluorescence spectroscopy, comprising the following steps: A1. Obtaining oil samples of different types and concentrations, and obtaining the corresponding ultraviolet absorption spectra and three-dimensional fluorescence spectra; A2. Expanding the three-dimensional fluorescence data and ultraviolet absorption spectral data, corresponding to the excitation wavelength, and stitching the two together to obtain the fused spectrum, with absorbance as a separate column; A3. Decomposing the fused spectrum X and the dependent variable matrix Y; obtaining a set of T and U with the maximum covariance, thereby obtaining the model B=(T T T) ‑1 T T U; A4. Obtain a water sample, obtain the corresponding fusion spectrum according to A1 and A2, and use the model to obtain Y, thereby determining the type of oil in the water and the corresponding concentration. This invention has advantages such as accuracy.

The application relates to a COD online detection turbidity compensation method based on ultraviolet absorption spectrum, which comprises the following steps: preparing gradient COD standard solution, gradient turbidity standard solution and mixed solution, and measuring the absorption spectrum of various solutions; a COD concentration prediction model and a turbidity prediction model are established; the ultraviolet absorption spectrum of a mixed solution to be measured is collected, the characteristic wavelength absorbance is extracted and substituted into the turbidity prediction model to obtain a predicted turbidity value, a turbidity interference correction coefficient and an interference reference value are calculated, and the corrected COD true absorbance is generated; the corrected COD true absorbance is subjected to interval average processing, the comprehensive abnormal value is calculated, and the detection effectiveness is judged. The application has high reliability, can reduce the average relative error of COD detection through optimized modeling interval screening, multi-wavelength collaborative turbidity identification and scene compensation strategies, and cooperates with a closed-loop abnormal judgment mechanism, so that the detection result is still accurate and stable under a complex turbid water quality environment, and the actual water quality treatment can be effectively guided.

This invention discloses a rapid method for detecting the residual amount of polyacrylamide in manufactured sand, comprising: (1) mixing the manufactured sand sample to be tested with purified water, and extracting and filtering to obtain a filtrate containing polyacrylamide; (2) taking the filtrate prepared in step (1), detecting its ultraviolet absorption spectrum at 574 nm using the starch-cadmium iodide indicator method, and then obtaining the ultraviolet absorption spectrum data of polyacrylamide in the filtrate as A by comparing it with the control group; (3) substituting data A into the standard curve of polyacrylamide to obtain the concentration of polyacrylamide in the filtrate, and then converting it to obtain the residual amount of polyacrylamide in the manufactured sand. This invention discloses a method for detecting the residual amount of polyacrylamide in manufactured sand, which can rapidly and accurately measure the content of flocculant polyacrylamide in manufactured sand and reduce its impact on concrete performance.