Laser-induced breakdown spectroscopy line peak shape correction method, system, electronic device and medium

Abstract

The present invention discloses a laser induced breakdown spectrum line peak shape correction method system, electronic equipment and medium. The method uses a Gaussian function and an exponential function describing a leading / tailing to perform convolution to fit the original peak shape that needs to be corrected; determines the spectral peak that needs to be corrected; calculates the ridge slope of the spectral line peak shape on one side that needs to be adjusted, and uses the ridge slope of the ideal spectral line peak shape of the spectral peak as a benchmark to adjust the spectral line peak shape of the spectral peak and change the ridge slope, so that the ridge slope tends to the ridge slope on the side corresponding to the ideal spectral line peak shape; corrects the spectral line peak shape of the spectral peak; finally, fits the corrected peak shape curve with a Gaussian function, and analyzes the constituent elements and concentrations of the sample; the present invention improves the leading or tailing effect by changing the slope of the signal spectral line peak shape, ensures that the fitting curve can more closely fit the actual data points, can extract the main spectral features and make the peak shape steeper, thereby improving the accuracy of the analysis.

Description

Technical Field

[0001] The present invention relates to the technical field of spectrum analysis, and in particular to a method, system, electronic equipment and medium for correcting the peak shape of a laser-induced breakdown spectrum line. Background Art

[0002] Laser-induced breakdown spectroscopy (LIBS) is an emerging spectral analysis technique widely used in fields such as geology, chemistry, environmental science, and materials science. Its rapid, non-contact, highly sensitive, and simultaneous multi-element detection capabilities make it an effective solution for material surface analysis, elemental composition determination, and environmental monitoring.

[0003] During the LIBS process, continuous background interferences such as blackbody radiation, bremsstrahlung, and loading radiation can cause spectral baseline drift. Blackbody radiation originates from high-temperature electrons and ions in the plasma, forming a strong thermal radiation background; bremsstrahlung is continuous X-ray radiation produced by the interaction of high-speed electrons with atomic nuclei; and loading radiation is continuous radiation generated by the energy released during electron recombination. These background interferences not only elevate the spectral baseline, mask low-intensity characteristic spectral lines, and reduce the signal-to-noise ratio and resolution of the spectrum, but also affect the accuracy of quantitative analysis based on peak intensity or integrated area. To reduce the impact of these interferences, various methods can be adopted: selecting optimal measurement parameters, applying filtering techniques (such as exponential decay filters and wavelet transforms) to smooth the signal, using complex peak fitting models (such as GHVL) to correct for asymmetric peak shapes, and optimizing experimental conditions (such as laser energy, pulse width, and focusing distance) to improve plasma stability and spectral quality. These methods can effectively reduce background interferences, thereby improving the resolution of LIBS data and the accuracy of quantitative analysis.

[0004] While LIBS technology demonstrates significant advantages in multi-element detection, and its high sensitivity makes it a powerful tool for related detection tasks, practical applications still face challenges. For example, due to system deviations and the evolution of plasma at high temperatures, spectral lines exhibit asymmetric peaks, such as front drift or extended tails. This impacts the reliability and accuracy of analytical results. Summary of the Invention

[0005] Technical purpose: To address the shortcomings of existing LIBS spectral analysis, the present invention discloses a method, system, electronic equipment and medium for correcting the peak shape of laser-induced breakdown spectroscopy lines.

[0006] Technical solution: To achieve the above technical objectives, the present invention adopts the following technical solution:

[0007] A method for correcting the peak shape of a laser-induced breakdown spectroscopy line comprises the following steps:

[0008] S01. Obtain the LIBS spectrum of the sample through spectral measurement and observe the spectral peak;

[0009] S02, use the Gaussian function and the exponential function describing the leading / trailing to perform convolution to fit the original peak shape;

[0010] S03. For the fitted spectral peak curve, calculate the half-height width, asymmetry factor, and leading or tailing factor of the spectral peak line peak shape; and determine the spectral peak that needs to be corrected;

[0011] S04. Calculate the ridge slope of the spectral line peak shape on one side that needs to be adjusted, and use the ridge slope of the ideal spectral line peak shape of the spectral peak as a benchmark to adjust the ridge slope of the spectral line peak shape of the spectral peak so that the ridge slope tends to the ridge slope on the corresponding side of the ideal spectral line peak shape; correct the spectral line peak shape of the spectral peak; finally, fit the corrected peak shape curve with a Gaussian function to analyze the composition elements and concentration of the sample.

[0012] Preferably, in step S02 of the present invention, the process of fitting the original peak shape includes: fitting the spectral peak using a Gaussian distribution function to obtain an initial Gaussian peak shape f(x), and using an exponential function E(x) for the leading peak or the trailing peak part. t ) to express, T is the original spectrum peak tailing factor, x t It is the intersection of the peak height 5% and the peak; the exponentially modified Gaussian function model curve obtained after convolution is y EMG =f(x)*E(x t ).

[0013] Preferably, in step S04 of the present invention, the process of adjusting the spectral line peak shape of the spectral peak to change the ridge slope includes: converting the ridge slope into a corresponding inclination angle, and confirming the inclination angle adjustment range according to the difference between the spectral line peak shape of the spectral peak and the inclination angle of the ideal spectral line peak shape of the spectral peak, and adjusting the spectral line peak shape of the spectral peak with 1° as the step unit. After each adjustment, the half-height width of the adjusted spectral line peak shape is calculated until the final half-height width position point is symmetrical with the spectral line peak shape on the other side. At this time, the ridge slope of the spectral line peak shape of the spectral peak is consistent with the ridge slope of the ideal spectral line peak shape.

[0014] Preferably, when calculating the ridge slope of the spectral peak shape and the ideal spectral line shape of the spectral peak, the intersection point from the spectral peak apex to the corresponding peak shape and 5% of the peak height is used as the endpoint for calculating the slope.

[0015] Preferably, before performing the original peak shape fitting in step S02, the present invention first segments the ridge line on the leading or trailing side using the node corresponding to the half-width position of the spectral peak of the original peak shape as the dividing point, calculates the ridge line slope from the half-width position to the peak top and the slope from the half-width position to the peak bottom of the spectrum line, first modulates the slope from the half-width position to the peak bottom to be consistent with the ridge line slope from the half-width position to the peak top, and then fits the peak shape.

[0016] The invention discloses a laser induced breakdown spectrum tailing adaptive correction system, which uses the correction method to correct the laser induced breakdown spectrum.

[0017] The present invention discloses an electronic device, comprising a memory, a processor, and a computer program stored in the memory and runnable on the processor. When the processor executes the program, a method for correcting the peak shape of a laser induced breakdown spectroscopy line is implemented as described in any one of claims 1 to 6.

[0018] A computer-readable storage medium stores computer-executable instructions, wherein the computer-executable instructions are used to execute the above-mentioned method for correcting the peak shape of a laser-induced breakdown spectroscopy line.

[0019] Beneficial effects: The laser-induced breakdown spectroscopy line peak shape correction method, system, electronic device and medium disclosed in the present invention have the following beneficial effects:

[0020] 1. The present invention improves the leading or tailing effect by changing the slope of the signal spectrum peak, ensuring that the fitting curve can fit the actual data points more closely, and can extract the main spectral features to make the peak steeper, thereby improving the accuracy of the analysis.

[0021] 2. The present invention uses a Gaussian function and an exponential function describing the leading or trailing to perform convolution to fit the original peak shape, and pre-processes the peak shape to adjust the asymmetric part of the peak shape, thereby providing a more flexible and accurate fitting result, which is convenient for subsequent adjustment of the peak ridge slope.

[0022] 3. Before fitting the original peak shape, the present invention pre-adjusts the areas with severe leading or tailing according to the slopes of the upper and lower parts of the half-height width position, thereby narrowing the scope of subsequent overall slope adjustment, improving the efficiency of spectrum correction, and ensuring the accuracy of the correction results. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for describing the embodiments or the prior art.

[0024] Figure 1 Schematic diagram of the peak shape curve in the front and tailing states of the spectrum peak;

[0025] Figure 2 This is a schematic diagram of the original peak shape fitting of the present invention;

[0026] Figure 3 Schematic diagram of the process of adjusting the ridge slope of the spectral peak shape curve according to the present invention. DETAILED DESCRIPTION

[0027] Reference will now be made in detail to the embodiments of the present disclosure, one or more examples of which are set forth herein below. Each embodiment and example is provided by way of explanation of the apparatus, composition, and materials of the present disclosure, and is not intended to be limiting. On the contrary, the following description provides a convenient illustration of exemplary embodiments for implementing the present disclosure. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made within the teachings of the present disclosure without departing from the scope or spirit of the present disclosure.

[0028] like Figure 1-Figure 3 As shown, the present invention discloses a method for correcting the peak shape of a laser-induced breakdown spectroscopy line, comprising the steps of:

[0029] S01. Obtain the LIBS spectrum of the sample through spectral measurement and observe the spectral peak;

[0030] S02, use the Gaussian function and the exponential function describing the leading / trailing to perform convolution to fit the original peak shape;

[0031] In step S02 of the present invention, the process of fitting the original peak shape includes: fitting the spectral peak using a Gaussian distribution function to obtain an initial Gaussian peak shape f(x). Under the Gaussian peak shape, the spectral intensity is Where A is the peak area, x is the location of the peak half-height, x0 is the peak center, and σ is the standard deviation.

[0032] And for the tail or front part exponential function E(x t ) to express, T is the leading or tailing factor of the original spectrum peak, x t It is the intersection of the peak height 5% and the peak; the exponentially modified Gaussian function model curve obtained after convolution is y EMG =f(x)*E(x t ), in order to describe the peak shape of the spectrum.

[0033] S03. For the fitted spectral peak curve, calculate the half-height width, asymmetry factor, and leading or tailing factor of the spectral peak line peak shape; determine the spectral peak that needs to be corrected, and correct the peak shape of the spectral peak that has leading or tailing;

[0034] The present invention Figure 2A schematic diagram of the peak shape in the case of pre-position is given in FIG. In this case, it is necessary to correct the peak curve of the pre-position part on the left side of the figure to maintain the overall correction of the spectral peak line and eliminate the influence of the pre-position part on the spectral analysis.

[0035] In the present invention Figure 2 In the embodiment shown, the half-height width W 0.5h =a+b, a and b represent the distance from the center of the half-height width of the peak curve to the left and right sides of the spectrum, respectively; a' and b' represent the distance from the center of the height position of 5% of the peak height of the peak curve to the left and right sides of the spectrum; asymmetry factor leading or trailing factor; Where I(x t ) represents the spectral intensity at 5% of the spectral peak height, x t The horizontal coordinate represents the intersection of the 5% peak height and the peak shape line of the spectrum. When performing peak shape correction, the correction is also performed on the area above 5% peak height.

[0036] S04. Calculate the ridge slope of the spectral line peak shape on one side that needs to be adjusted, and use the ridge slope of the ideal spectral line peak shape of the spectral peak as a benchmark to adjust the ridge slope of the spectral line peak shape of the spectral peak so that the ridge slope tends to the ridge slope of the ridge on the corresponding side of the ideal spectral line peak shape; use the intersection of the spectral peak top to the corresponding peak shape and 5% of the peak height as the endpoint of the slope calculation to correct the spectral line peak shape of the spectral peak; finally, fit the corrected peak shape curve with a Gaussian function to analyze the composition elements and concentration of the sample.

[0037] like Figure 3 As shown, in step S04 of the present invention, the process of adjusting the spectral line peak shape of the spectral peak to change the ridge slope includes: converting the ridge slope into a corresponding inclination angle, and confirming the inclination angle adjustment range according to the difference between the spectral line peak shape of the spectral peak and the inclination angle of the ideal spectral line peak shape of the spectral peak, adjusting the spectral line peak shape of the spectral peak with 1° as a step unit, and calculating the half-height width of the adjusted spectral line peak shape after each adjustment until the final half-height width position point is symmetrical with the spectral line peak shape on the other side. At this time, the ridge slope of the spectral line peak shape of the spectral peak is consistent with the ridge slope of the ideal spectral line peak shape.

[0038] The slope of the spectral peak line Ideal spectral line shape I(x0) is the spectral intensity at the top of the spectral peak, x 0.05h It is the horizontal coordinate of the intersection of 5% peak height and the ideal peak shape spectrum line of the spectral peak.

[0039] The corresponding tilt angle is:

[0040] θ1=tan -1 (m1)

[0041] θ2=tan-1 (m2)

[0042] The adjustment angle range is θ=θ1-θ2, and the peak height before and after adjustment is 5% of the displacement on the x-axis x'=x 0.05h -x t .

[0043] As the θ angle changes, the corresponding tilt angle also changes. Therefore, the spectral peak shape can be gradually adjusted by angle step adjustment until a = b and m1 = m2. At this point, the peak shape adjustment is complete. Finally, the adjusted peak shape can be fitted with a Gaussian function to remove the interference components of the leading peak, which can significantly improve the spectral quality and make the spectrum more realistically reflect the characteristics of the sample. For the treatment of tailing peaks, refer to the treatment process of the leading peak and make corresponding adjustments.

[0044] At the same time, when adjusting the leading part or tailing part of the spectral peak, the actual leading part or tailing part is mainly concentrated in the area below the half-width of the peak shape. Considering that in the case of severe leading or tailing, the slope deviation between the peak shape of the spectral peak line and the ideal peak shape of the spectral peak line is large, resulting in a large angle range that needs to be adjusted during correction, thereby increasing the difficulty of correction. For this reason, before the original peak shape is fitted in step S02, the present invention first segments the ridge line on the leading or tailing side with the node corresponding to the half-width position of the spectral peak of the original peak shape as the dividing point, calculates the ridge line slope from the half-width position to the peak top and the slope from the half-width position to the peak bottom of the spectral line, first modulates the slope from the half-width position to the peak bottom to be consistent with the ridge line slope from the half-width position to the peak top, and then fits the peak shape to further reduce the influence of the leading or tailing on the spectral peak, thereby greatly reducing the range of subsequent slope adjustment, improving the correction efficiency of the spectral peak shape, realizing rapid analysis of the sample spectrum line, and correspondingly improving the detection efficiency.

Claims

1. A method for correcting the peak shape of laser-induced breakdown spectroscopy lines, characterized in that: Including steps: S01. Obtain the LIBS spectrum of the sample through spectral measurement and observe the spectral peak; S02, use the Gaussian function and the exponential function describing the leading / trailing to perform convolution to fit the original peak shape; S03. For the fitted spectral peak curve, calculate the half-height width, asymmetry factor, and leading or tailing factor of the spectral peak line peak shape; and determine the spectral peak that needs to be corrected; S04. Calculate the ridge slope of the spectral line peak that needs to be adjusted on one side, and use the ridge slope of the ideal spectral line peak shape of the spectral peak as a benchmark to adjust the ridge slope of the spectral line peak shape so that the ridge slope approaches the ridge slope of the spectral line peak shape on the side corresponding to the ideal spectral line peak shape; correct the spectral line peak shape of the spectral peak; finally, fit the corrected peak shape curve with a Gaussian function to analyze the composition elements and concentrations of the sample; In step S02, the process of fitting the original peak shape includes: fitting the spectral peak using a Gaussian distribution function to obtain an initial Gaussian peak shape f(x), and fitting the tailing part using a tailing exponential function E(x t ) to express, T is the original spectrum peak tailing factor, x t It is the intersection of the peak height 5% and the peak; the exponentially modified Gaussian function model curve obtained after convolution is y EMG =f(x)*E(x t ); In step S04, the process of adjusting the peak shape of the spectrum line of the spectrum peak to change the ridge slope includes: converting the ridge slope into a corresponding tilt angle, and determining the tilt angle adjustment range according to the difference between the peak shape of the spectrum line of the spectrum peak and the tilt angle of the ideal spectrum line peak shape of the spectrum peak, adjusting the peak shape of the spectrum line of the spectrum peak in 1° steps, and calculating the half-height width of the adjusted spectrum line peak shape after each adjustment until the point at the final half-height width position is symmetrical with the spectrum line peak shape on the other side, at which point the ridge slope of the spectrum line peak shape of the spectrum peak is consistent with the ridge slope of the ideal spectrum line peak shape; When calculating the ridge slope of the spectral peak shape and the ideal spectral line shape of the spectral peak, the intersection point from the spectral peak top to the corresponding peak shape and 5% of the peak height is used as the endpoint for calculating the slope.

2. The method for correcting the peak shape of a laser-induced breakdown spectroscopy line according to claim 1, characterized in that: Before fitting the original peak shape in step S02, the ridge line on the leading or trailing side is segmented using the node corresponding to the half-width position of the spectral peak of the original peak shape as the dividing point, and the slope of the ridge line from the half-width position to the peak top and the slope from the half-width position to the peak bottom of the spectrum line are calculated. The slope from the half-width position to the peak bottom is first modulated to be consistent with the slope of the ridge line from the half-width position to the peak top, and then the peak shape is fitted.

3. A laser induced breakdown spectrum tailing adaptive correction system, characterized in that: The laser induced breakdown spectrum is corrected using the correction method described in any one of claims 1 to 2.

4. An electronic device, characterized in that: The invention comprises a memory, a processor and a computer program stored in the memory and capable of running on the processor. When the processor executes the program, a method for correcting the peak shape of a laser induced breakdown spectroscopy line is implemented as described in any one of claims 1 to 2.

5. A computer-readable storage medium storing computer-executable instructions, characterized in that: The computer executable instructions are used to execute the laser induced breakdown spectroscopy line peak shape correction method described in any one of claims 1-2.

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