A method for determining initial parameters of transient absorption spectroscopy kinetic curves

Abstract

The embodiment of the application provides a method for determining initial parameters of a transient absorption spectrum dynamic curve, which comprises the following steps: obtaining an initial absorption point and an absorption decay termination point of the transient absorption spectrum dynamic curve, determining a curve segment between the initial absorption point and the absorption decay termination point as an absorption decay total interval; performing weighted processing on a first derivative and a second derivative of the transient absorption spectrum dynamic curve to obtain a weighted curvature value sequence; selecting the first N-1 weighted curvature values in the weighted curvature value sequence in descending order, and dividing the absorption decay total interval into N absorption decay intervals corresponding to the fitting order of the curve according to the sampling points corresponding to the first N-1 weighted curvature values; and determining the initial parameters based on the absorption intensity at the interval starting point in each absorption decay interval in the exponential fitting model, the quantitative relationship that the absorption intensity decays to 1 / e of the absorption intensity at the starting point of the corresponding interval. The fitting efficiency and accuracy of the dynamic curve are improved.

Description

Technical Field

[0001] This application belongs to the field of data analysis technology, and in particular relates to a method for determining the initial parameters of a transient absorption spectral dynamics curve. Background Technology

[0002] Transient absorption spectroscopy (TAS) is an important spectroscopic analysis technique for studying ultrafast processes in molecular systems. This method excites a sample with a femtosecond or picosecond laser and measures the changes in absorption signal at different delay times, thereby obtaining information on energy transfer, electronic relaxation, molecular conformational changes, and chemical reaction kinetics in the excited state. Due to its high time resolution and sensitivity, transient absorption spectroscopy has become an important experimental tool for studying carrier dynamics in optoelectronic materials, photosynthetic mechanisms, and the dynamic characteristics of novel functional molecules.

[0003] However, transient absorption spectra often exhibit complex temporal characteristics, including multi-stage attenuation, signal overlap, noise interference, and baseline drift. Existing methods for fitting the dynamic curves of transient absorption spectra typically rely on nonlinear least-squares fitting algorithms, which are extremely sensitive to the selection of initial parameters. Inappropriate initial parameter settings can frequently lead to fitting results deviating from the actual physical meaning, computational non-convergence, or getting trapped in local optima, severely impacting the reliability and repeatability of the fitting. Traditional global search-based algorithms (such as genetic algorithms and particle swarm optimization) can avoid local minima to some extent, but they are computationally expensive and still require a manually defined initial search range. This manually defined initial search range is highly subjective and suffers from low fitting efficiency.

[0004] Therefore, how to automatically determine the initial parameters of the transient absorption spectral dynamics curve to ensure the accuracy of subsequent curve fitting and improve the efficiency of curve fitting is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] This application provides a method, apparatus, device, and computer storage medium for determining the initial parameters of a transient absorption spectral dynamic curve. This solves the problems of existing dynamic curve fitting processes where the initial parameters need to be given a reasonable initial search range manually, resulting in strong subjectivity of the initial search range and low fitting efficiency.

[0006] In a first aspect, embodiments of this application provide a method for determining the initial parameters of a transient absorption spectral dynamics curve, the method comprising:

[0007] Obtain the initial absorption point and the absorption attenuation termination point of the transient absorption spectral dynamics curve; the absorption attenuation termination point is the first sampling point in the sampling interval where the rate of change of absorption intensity is continuously lower than a first preset threshold in the transient absorption spectral dynamics curve.

[0008] The segment of the transient absorption spectral dynamics curve located between the initial absorption point and the absorption attenuation termination point is defined as the total absorption attenuation interval.

[0009] The first and second derivatives of the transient absorption spectral dynamics curve are weighted to obtain a weighted curvature value sequence.

[0010] In the weighted curvature value sequence, the first N-1 weighted curvature values ​​are selected in descending order. Based on the sampling points in the transient absorption spectral dynamics curve corresponding to the first N-1 weighted curvature values, the total absorption attenuation interval is divided into N absorption attenuation intervals corresponding to the curve fitting order; N is a positive integer.

[0011] Based on the quantization relationship between the absorption intensity at the starting point of each absorption attenuation interval in the exponential fitting model and the absorption intensity attenuating to 1 / e of the corresponding starting point of the interval, N sets of parameters corresponding to the N absorption attenuation intervals are determined as initial parameters.

[0012] In one feasible implementation, based on the quantization relationship of the absorption intensity at the starting point of each absorption attenuation interval in the exponential fitting model, which decays to 1 / e of the absorption intensity at the corresponding starting point of the interval, N sets of parameters corresponding to the N absorption attenuation intervals are determined as initial parameters, which may include:

[0013] Based on the difference between the absorption intensity at the start of each absorption attenuation interval and the absorption intensity at the end of the interval, the target absorption intensity value is determined to be 1 / e times the absorption intensity at the start of the interval within each absorption attenuation interval.

[0014] The target absorption intensity value within each absorption attenuation interval is used as the initial amplitude parameter within the corresponding absorption attenuation interval.

[0015] Determine the target sampling points corresponding to the target absorption intensity values ​​within each absorption attenuation interval;

[0016] The time difference between the target sampling point and the initial absorption point in each absorption attenuation interval is used as the initial time parameter in the corresponding absorption attenuation interval.

[0017] The initial amplitude parameter and initial time parameter corresponding to each absorption attenuation interval are used as the initial parameters.

[0018] In one feasible implementation, N can be set to 2;

[0019] In the weighted curvature value sequence, the first N-1 weighted curvature values ​​are selected in descending order. Based on the sampling points in the transient absorption spectral dynamics curve corresponding to each of the first N-1 weighted curvature values, the total absorption attenuation interval is divided into N absorption attenuation intervals corresponding to the curve fitting order. These intervals may include:

[0020] The maximum weighted curvature value is selected from the weighted curvature value sequence. Based on the sampling point in the transient absorption spectral dynamics curve corresponding to the maximum weighted curvature value, the total absorption attenuation interval is divided into an interval from the initial absorption point to the sampling point and an interval from the sampling point to the absorption attenuation termination point.

[0021] In one feasible implementation, N can be set to 3;

[0022] In the weighted curvature value sequence, the first N-1 weighted curvature values ​​are selected in descending order. Based on the sampling points in the transient absorption spectral dynamics curve corresponding to each of the first N-1 weighted curvature values, the total absorption attenuation interval is divided into N absorption attenuation intervals corresponding to the curve fitting order. These intervals may include:

[0023] The first two weighted curvature values ​​are selected from the weighted curvature value sequence in descending order; the first two weighted curvature values ​​include the first weighted curvature value and the second weighted curvature value.

[0024] Determine the first sampling point in the transient absorption spectral dynamics curve corresponding to the first weighted curvature value, and the second sampling point in the transient absorption spectral dynamics curve corresponding to the second weighted curvature value;

[0025] Based on the first and second sampling points, the total absorption attenuation interval is divided into a first interval from the initial absorption point to the first sampling point, a second interval from the first sampling point to the second sampling point, and a third interval from the second sampling point to the absorption attenuation termination point.

[0026] In one feasible implementation, before selecting the first two weighted curvature values ​​in descending order from the weighted curvature value sequence, the method may further include:

[0027] Obtain the first average of all weighted curvature values ​​in the weighted curvature value sequence, and the second average of all second derivatives;

[0028] Several first target weighted curvature values ​​are selected from the weighted curvature value sequence to form the first target weighted curvature value sequence; the first target weighted curvature value is greater than or equal to the first average value, and the second derivative of the target weighted curvature value at the same sampling point is greater than or equal to the second average value;

[0029] Selecting the first two weighted curvature values ​​from the weighted curvature value sequence in descending order can include:

[0030] The first two weighted curvature values ​​of the first objective are selected in descending order from the first objective weighted curvature value sequence.

[0031] In one feasible implementation, the method may further include:

[0032] In the first target weighted curvature value sequence, if the time difference between adjacent first target weighted curvature values ​​is less than the second preset threshold, only the maximum value among adjacent first target weighted curvature values ​​is retained to obtain the second target weighted curvature value sequence; the second preset threshold is a threshold set based on the length of the total absorption attenuation interval.

[0033] Selecting the first two first target weighted curvature values ​​from the first target weighted curvature value sequence in descending order can include:

[0034] The first two weighted curvature values ​​of the second objective are selected in descending order from the sequence of weighted curvature values ​​of the second objective.

[0035] In one feasible implementation, the first and second derivatives of the transient absorption spectral dynamics curve are weighted to obtain a weighted curvature value sequence, which may include:

[0036] Select several local second-order derivative extrema within the total absorption attenuation interval;

[0037] By weighting the local second derivative extrema and the first derivative in the same time series, a weighted curvature value sequence is obtained.

[0038] In one feasible implementation, before obtaining the initial absorption point and the absorption decay termination point of the transient absorption spectral kinetics curve, the method may further include:

[0039] Obtain the original transient absorption spectral dynamics curve;

[0040] The original transient absorption spectral dynamics curve is smoothed to obtain the transient absorption spectral dynamics curve.

[0041] In one feasible implementation, the method may further include:

[0042] Obtain the starting point of the response time of the transient absorption spectral dynamics curve;

[0043] The transient absorption spectral dynamics curve segment located between the start of the response time and the initial absorption point is defined as the response interval of the transient absorption spectral dynamics curve;

[0044] Obtain the extreme values ​​of absorption intensity in the transient absorption spectral dynamics curve within the response interval, and use them as the initial amplitude parameters for the response stage;

[0045] The midpoint of the response interval is used as the initial center parameter of the response phase;

[0046] Use the time difference of the response interval as the initial width parameter of the response phase;

[0047] The initial amplitude parameter, initial center parameter, and initial width parameter of the response phase are used as the initial parameters for the Gaussian function fitting model of the instrument response phase.

[0048] In one feasible implementation, obtaining the initial absorption point of the transient absorption spectral dynamics curve may include:

[0049] Obtain the average absorption intensity of the transient absorption spectral dynamics curve;

[0050] If the absorption intensity at the absorption attenuation termination point is greater than the average absorption intensity, the sampling point corresponding to the minimum absorption intensity in the transient absorption spectral kinetic curve is selected as the initial absorption point.

[0051] When the absorption intensity value at the absorption attenuation termination point is less than or equal to the average absorption intensity, the sampling point corresponding to the maximum absorption intensity in the transient absorption spectral kinetic curve is selected as the initial absorption point.

[0052] Secondly, embodiments of this application provide an initial parameter determination device for a transient absorption spectral dynamics curve, the device comprising:

[0053] The feature point acquisition module is used to acquire the initial absorption point and the absorption attenuation termination point of the transient absorption spectral dynamics curve; the absorption attenuation termination point is the first sampling point in the sampling interval where the rate of change of absorption intensity is continuously lower than a first preset threshold in the transient absorption spectral dynamics curve.

[0054] The module for determining the total absorption attenuation range is used to determine the curve segment in the transient absorption spectral dynamics curve located between the initial absorption point and the absorption attenuation termination point as the total absorption attenuation range.

[0055] The weighted curvature value sequence acquisition module is used to perform weighted processing on the first and second derivatives of the transient absorption spectrum dynamic curve to obtain a weighted curvature value sequence.

[0056] The absorption attenuation interval division module is used to select the first N-1 weighted curvature values ​​in descending order from the weighted curvature value sequence, and divide the total absorption attenuation interval into N absorption attenuation intervals corresponding to the curve fitting order based on the sampling points in the transient absorption spectral dynamics curve corresponding to the first N-1 weighted curvature values; N is a positive integer.

[0057] The initial parameter determination module is used to determine N sets of parameters corresponding to N absorption attenuation intervals as initial parameters, based on the quantitative relationship between the absorption intensity at the starting point of each absorption attenuation interval in the exponential fitting model and the absorption intensity at the starting point of the corresponding interval decreasing to 1 / e.

[0058] Thirdly, embodiments of this application provide an initial parameter determination device for a transient absorption spectral dynamics curve. The device includes: a processor and a memory storing computer program instructions; the processor reads and executes the computer program instructions to implement any of the initial parameter determination methods for transient absorption spectral dynamics curves in the above embodiments.

[0059] Fourthly, embodiments of this application provide a computer storage medium storing computer program instructions, which, when executed by a processor, implement the method for determining the initial parameters of the transient absorption spectral dynamics curve as described in any of the above embodiments.

[0060] Fifthly, embodiments of this application provide a computer program product, including a computer program that, when executed, implements a method for determining the initial parameters of any of the transient absorption spectral dynamics curves described in the above embodiments.

[0061] The method, apparatus, device, computer storage medium, and computer program product for determining the initial parameters of the transient absorption spectral dynamics curve according to embodiments of this application can determine the entire absorption attenuation segment of the transient absorption spectral dynamics curve by obtaining the initial absorption point and the absorption attenuation termination point of the transient absorption spectral dynamics curve. By performing first and second derivatives on the transient absorption spectral dynamics curve, and when corresponding to multi-order exponential fitting, the obtained first and second derivatives are used to determine the dividing points. Using the first derivative avoids including the attenuation termination interval, which tends to stabilize, in the transient absorption spectral dynamics curve. Using the second derivative ensures that the selected dividing points are at the points where the absorption intensity changes. The high degradation rate improves the accuracy of the dividing point selection and enhances the accuracy of dividing multiple absorption decay intervals with different absorption decay rates within the entire absorption decay segment of the transient absorption spectral dynamics curve based on this dividing point. Based on the quantization relationship of absorption intensity at the starting point of each absorption decay interval in the exponential fitting model, which decays to 1 / e of the absorption intensity at the corresponding starting point, N sets of parameters corresponding to N absorption decay intervals are determined as initial parameters. This enables the automatic determination of the initial parameters for the transient absorption spectral dynamics curve, improving the fitting efficiency and accuracy of the transient absorption spectral dynamics curve. Attached Figure Description

[0062] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0063] Figure 1 This is a flowchart illustrating a method for determining the initial parameters of a transient absorption spectral dynamics curve provided in an embodiment of this application.

[0064] Figure 2 This is a flowchart illustrating a method for obtaining the initial absorption point of a transient absorption spectral dynamics curve according to an embodiment of this application.

[0065] Figure 3 This is a flowchart illustrating a preprocessing method provided in an embodiment of this application;

[0066] Figure 4 This is a flowchart illustrating a weighted processing method provided in an embodiment of this application;

[0067] Figure 5 This is a flowchart illustrating a method for dividing an absorption attenuation interval according to an embodiment of this application;

[0068] Figure 6This is a flowchart illustrating a screening method provided in an embodiment of this application;

[0069] Figure 7 This is a flowchart illustrating a method for determining initial parameters within an absorption attenuation range, as provided in an embodiment of this application.

[0070] Figure 8 This is a flowchart illustrating a response stage fitting method provided in an embodiment of this application;

[0071] Figure 9 This is an example diagram of a dynamic curve with double exponential fitting provided in an embodiment of this application;

[0072] Figure 10 This is an example diagram of a single-exponential fitting result of a dynamic curve provided in an embodiment of this application;

[0073] Figure 11 This is an example diagram of a double exponential fitting result of a dynamic curve provided in an embodiment of this application;

[0074] Figure 12 This is an example diagram of a three-exponential fitting result of a dynamic curve provided in an embodiment of this application;

[0075] Figure 13 This is an example diagram of a single-exponential fitting result of another dynamic curve provided in the embodiments of this application;

[0076] Figure 14 This is an example diagram of a double exponential fitting result of another dynamic curve provided in the embodiments of this application;

[0077] Figure 15 This is an example diagram of a three-exponential fitting result of another dynamic curve provided in the embodiments of this application;

[0078] Figure 16 This is a schematic diagram of the structure of an initial parameter determination device for transient absorption spectral dynamics curves provided in an embodiment of this application;

[0079] Figure 17 This is a schematic diagram of the structure of a device for determining the initial parameters of a transient absorption spectral dynamics curve provided in an embodiment of this application. Detailed Implementation

[0080] The features and exemplary embodiments of various aspects of this application will be described in detail below. To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain this application and not to limit it. For those skilled in the art, this application can be implemented without some of these specific details. The following description of the embodiments is merely to provide a better understanding of this application by illustrating examples.

[0081] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes said element.

[0082] Since transient absorption signals often exhibit complex time evolution characteristics, existing techniques often require the use of multi-exponential models (such as double-exponential or other multi-exponential models) to fit the absorption signals in order to analyze the characteristic time constants and their relative contributions of different physical processes. Generally, the formula for fitting the exponential decay of transient absorption spectral dynamics is shown in the following formula (1):

[0083] (1);

[0084] In formula (1), M is the order of the exponential fit (usually 1-3). and The parameters for the exponential fit are the magnitude parameter and the time parameter, respectively. This represents the steady-state term. It addresses the issue that nonlinear least squares fitting algorithms are extremely sensitive to the selection of initial parameters.

[0085] Currently, researchers and engineers typically rely on experience or multiple trial calculations to determine initial parameters. However, this method is not only time-consuming and labor-intensive, but also highly subjective, easily affected by experimental noise and individual differences in judgment, making it difficult to maintain consistency in batch data processing. With the significant increase in the amount of ultrafast spectroscopy experimental data and the growing demand for automated analysis, traditional manual parameter tuning methods are no longer sufficient to meet the requirements of high-throughput and standardized processing.

[0086] Furthermore, during the fitting of dynamic curves, the signal exhibits significant differences in time scale across different processes, and the signal-to-noise ratio fluctuates nonlinearly with the delay time, further increasing the difficulty of initial parameter estimation. While traditional global search-based algorithms (such as genetic algorithms and particle swarm optimization) can avoid local minima to some extent, they are computationally expensive and still require a manually defined initial search range.

[0087] Therefore, how to automatically determine the initial parameters of the transient absorption spectral dynamics curve to ensure the accuracy of subsequent curve fitting and improve the efficiency of curve fitting is a problem that urgently needs to be solved by those skilled in the art.

[0088] To address the problems in the prior art, this application provides a method for determining the initial parameters of a transient absorption spectral dynamics curve.

[0089] The method provided in this application first smooths the transient absorption spectral dynamics curve by using a filtering algorithm to suppress noise and correct the baseline. Then, it calculates the first and second derivatives of the transient absorption spectral dynamics curve and analyzes their trends, automatically identifying the global extremum and the absorption decay termination point. The global extremum is the initial absorption point of the transient absorption spectral dynamics curve, thus determining the absorption decay stage of the curve. Based on the rate of change of the derivative and the decay law of the absorption intensity, the absorption decay stage of the dynamics curve is divided into fast and slow process intervals. The initial time constant within each fast and slow process interval is estimated based on the characteristic point where the absorption intensity in each interval decreases to 1 / e of the absorption intensity of the current interval.

[0090] In addition to the basic exponential decay fitting, it is necessary to simultaneously fit the instrument response function (IRF) and the decay process. The IRF reflects the instrument's time resolution and describes the transient changes in the system's response to the input signal. It can usually be modeled using a Gaussian function, and its expression can be found in the following formula (2):

[0091] (2);

[0092] In formula (1), A is the amplitude parameter. Center parameter, This is the width parameter. Generally, IRF is not performed alone, but rather in conjunction with exponential decay fitting. The formula for joint fitting is... This refers to convolution operations. In this application, the initial parameters of the instrument response function are calculated using Gaussian fitting, further improving the fitting accuracy of the kinetic curve. Finally, the initial parameters of the single-exponential, double-exponential, and triple-exponential models are calculated using the amplitude differences and event differences in each process interval of the absorption decay stage, including the initial amplitude parameters, initial time parameters, and steady-state terms for fast and slow processes. This method achieves high-precision estimation of initial parameters without manual intervention, and has advantages such as fast computation speed, strong robustness, and wide applicability. It can be used for automatic fitting and parameter extraction of transient absorption spectral kinetic curves of complex systems.

[0093] The method for determining the initial parameters of the transient absorption spectral dynamics curve provided in the embodiments of this application will be introduced first.

[0094] Figure 1 A schematic flowchart illustrating the initial parameter determination method for transient absorption spectral dynamics curves provided in one embodiment of this application is shown. Figure 1 As shown, the method may include the following steps:

[0095] S101: Obtain the initial absorption point and the absorption attenuation termination point of the transient absorption spectral dynamics curve; the absorption attenuation termination point is the first sampling point in the sampling interval where the rate of change of absorption intensity is continuously lower than the first preset threshold in the transient absorption spectral dynamics curve.

[0096] S102: The curve segment in the transient absorption spectral dynamics curve located between the initial absorption point and the absorption attenuation termination point is defined as the total absorption attenuation interval;

[0097] S103: Weight the first and second derivatives of the transient absorption spectral dynamics curve to obtain a weighted curvature value sequence;

[0098] S104: Select the first N-1 weighted curvature values ​​in descending order from the weighted curvature value sequence, and divide the total absorption attenuation interval into N absorption attenuation intervals corresponding to the curve fitting order based on the sampling points in the transient absorption spectral dynamics curve corresponding to the first N-1 weighted curvature values; N is a positive integer.

[0099] S105: Based on the quantitative relationship between the absorption intensity at the starting point of each absorption attenuation interval in the exponential fitting model and the absorption intensity attenuating to 1 / e of the corresponding starting point of the interval, determine N sets of parameters corresponding to N absorption attenuation intervals as initial parameters.

[0100] The following is a detailed explanation of each step:

[0101] S101: Obtain the initial absorption point and the absorption attenuation termination point of the transient absorption spectral dynamics curve; the absorption attenuation termination point is the first sampling point in the sampling interval where the rate of change of absorption intensity is continuously lower than the first preset threshold in the transient absorption spectral dynamics curve.

[0102] In this embodiment, the initial absorption point of the transient absorption spectral dynamics curve is the critical moment when the sample begins to absorb the probe light. After this point, the probe light attenuates upon absorption, making this initial absorption point an extreme point of the transient absorption spectral dynamics curve. Since the absorption intensity on the curve can have both positive and negative values, this initial absorption point is either a maximum or minimum point of the transient absorption spectral dynamics curve, essentially an extreme point of the absolute value of the transient absorption spectral dynamics curve. The aforementioned absorption attenuation termination point is selected as the first sampling point in the transient absorption spectral dynamics curve after it has stabilized. Specifically, this is achieved by selecting the first sampling point in the sampling interval where the rate of change of absorption intensity is continuously lower than a first preset threshold. This sampling interval is a continuous interval including the last sampling point in the transient absorption spectral dynamics curve, i.e., the last interval of the curve.

[0103] In one feasible embodiment, to accurately obtain the initial absorption point of the transient absorption spectral dynamics curve, the above-mentioned method of obtaining the initial absorption point of the transient absorption spectral dynamics curve may include the following steps. For details, please refer to... Figure 2 , Figure 2 This is a schematic flowchart of a method for obtaining the initial absorption point of a transient absorption spectral dynamics curve provided in an embodiment of this application.

[0104] S201: Obtain the average absorption intensity of the transient absorption spectral dynamics curve;

[0105] S202: When the absorption intensity value at the absorption attenuation termination point is greater than the average absorption intensity, select the sampling point corresponding to the minimum absorption intensity in the transient absorption spectral dynamics curve as the initial absorption point;

[0106] S203: When the absorption intensity value at the absorption attenuation termination point is less than or equal to the average absorption intensity, select the sampling point corresponding to the maximum absorption intensity in the transient absorption spectral kinetic curve as the initial absorption point.

[0107] In this embodiment, the average absorption intensity in the transient absorption spectral dynamics curve is used as a benchmark to compare with the absorption attenuation termination point in the transient absorption spectral dynamics curve, thereby determining the overall trend of the transient absorption spectral dynamics curve, determining whether the initial absorption point in the transient absorption spectral dynamics curve is a maximum or minimum point, and further determining the extreme point in the transient absorption spectral dynamics curve as the initial absorption point.

[0108] In one feasible embodiment, to suppress the impact of noise on the accuracy of transient absorption spectral dynamics analysis, the method may further include the following steps before obtaining the initial absorption point and absorption attenuation termination point of the transient absorption spectral dynamics curve. For details, please refer to... Figure 3 , Figure 3 This is a flowchart illustrating a preprocessing method provided in an embodiment of this application.

[0109] S301: Obtain the original transient absorption spectral dynamics curve;

[0110] S302: Smooth the original transient absorption spectral dynamics curve to obtain the transient absorption spectral dynamics curve.

[0111] The raw transient absorption spectral dynamics curves obtained in this embodiment are unprocessed raw transient absorption spectral dynamics curves. This embodiment smooths the obtained raw transient absorption spectral dynamics curves, reducing noise interference without affecting the main dynamic characteristics, thus achieving noise suppression and improving the accuracy of transient absorption spectral dynamics curve analysis. Specifically, this embodiment uses a filtering algorithm to smooth the raw transient absorption spectral dynamics curves, achieving noise suppression of the curves.

[0112] S102: The curve segment in the transient absorption spectral dynamics curve located between the initial absorption point and the absorption attenuation termination point is determined as the total absorption attenuation interval.

[0113] In this embodiment of the application, the process of analyzing the initial parameters of the transient absorption spectral dynamics curve only selects the interval between the initial absorption point and the absorption attenuation termination point in the transient absorption spectral dynamics curve for analysis, and takes this interval as the total absorption attenuation interval.

[0114] S103: Weight the first and second derivatives of the transient absorption spectral dynamics curve to obtain a weighted curvature value sequence.

[0115] In this embodiment, the first derivative of the transient absorption spectral dynamics curve is used to characterize the rate of change of absorption intensity in the transient absorption spectral dynamics curve. To avoid dividing the total absorption attenuation interval into a corresponding number of absorption attenuation intervals later, when selecting the division points, sampling points that tend to be stable in the transient absorption spectral dynamics curve are determined as division points. It is necessary to exclude sampling points with low rates of change of absorption intensity based on the first derivative of the transient absorption spectral dynamics curve. The second derivative of the transient absorption spectral dynamics curve is used to characterize the rate of change of absorption intensity in the transient absorption spectral dynamics curve, which can be understood as the acceleration of the change of absorption intensity. Similarly, to accurately select the division points when dividing the total absorption attenuation interval into a corresponding number of absorption attenuation intervals later, the acceleration of the change of absorption intensity in the transient absorption spectral dynamics curve can be used as the above-mentioned division points, which can facilitate the accurate division of the total absorption attenuation interval into absorption attenuation intervals with different attenuation rates. In this embodiment, the absorption attenuation intervals with different attenuation rates mainly reflect the dominant factors affecting the absorption attenuation in the current absorption attenuation interval, while the dominant factors in the absorption attenuation intervals in later time sequences still have an influence before the current absorption attenuation interval. In this embodiment of the application, it should be noted that, in order to ensure that the weighted processing result is not affected by the excessive value of any one of the terms, after calculating the first and second derivatives of the transient absorption spectral dynamics curve, the first and second derivatives can be normalized respectively to ensure that the values ​​of each term in the weighted processing do not affect the weighted processing result.

[0116] In one feasible embodiment, to avoid the excessive amount of data in the weighted curvature value sequence affecting the processing efficiency of subsequent steps and to improve the efficiency of initial parameter determination, the above-mentioned weighted processing of the first and second derivatives of the transient absorption spectral dynamics curve to obtain the weighted curvature value sequence may include the following steps. For details, please refer to... Figure 4 , Figure 4 This is a flowchart illustrating a weighted processing method provided in an embodiment of this application.

[0117] S401: Select several local second derivative extrema in the total absorption attenuation interval;

[0118] S402: Weight the local second derivative extrema and the first derivative under the same time sequence to obtain the weighted curvature value sequence.

[0119] In this embodiment, some weighted curvature values ​​that do not meet the conditions can be removed by pre-screening, thus avoiding an excessive amount of data that would increase the computational burden. Specifically, this embodiment can divide the total absorption attenuation interval into a specified number of sub-intervals, and then select a local second derivative extremum in each sub-interval. This local second derivative extremum is used to determine the initial absorption point of the transient absorption spectral dynamics curve. That is, when the initial absorption point of the transient absorption spectral dynamics curve is obtained by taking the maximum point of the transient absorption spectral dynamics curve, the local second derivative extremum is the local second derivative maximum. When the initial absorption point of the transient absorption spectral dynamics curve is obtained by taking the minimum point of the transient absorption spectral dynamics curve, the local second derivative extremum is the local second derivative minimum.

[0120] S104: Select the first N-1 weighted curvature values ​​in descending order from the weighted curvature value sequence, and divide the total absorption attenuation interval into N absorption attenuation intervals corresponding to the curve fitting order based on the sampling points in the transient absorption spectral dynamics curve corresponding to the first N-1 weighted curvature values; N is a positive integer.

[0121] In this embodiment, the larger the weighted curvature value, the greater the likelihood that the sampling point corresponding to the weighted curvature value in the transient absorption spectral dynamics curve is as the dividing point for different absorption attenuation intervals. Therefore, in this embodiment, larger weighted curvature values ​​are selected as the corresponding dividing points in descending order to improve the rationality of the final obtained initial parameters and ensure effective fitting of the transient absorption spectral dynamics curve in the future.

[0122] In one feasible embodiment, to improve the efficiency of dividing the total absorption attenuation interval into a corresponding number of absorption attenuation intervals, when N is 2, the above-mentioned selection of the first N-1 weighted curvature values ​​in descending order from the weighted curvature value sequence, and the division of the total absorption attenuation interval into N absorption attenuation intervals corresponding to the curve fitting order based on the sampling points in the transient absorption spectral dynamics curve corresponding to the first N-1 weighted curvature values, may include:

[0123] The maximum weighted curvature value is selected from the weighted curvature value sequence. Based on the sampling point in the transient absorption spectral dynamics curve corresponding to the maximum weighted curvature value, the total absorption attenuation interval is divided into an interval from the initial absorption point to the sampling point and an interval from the sampling point to the absorption attenuation termination point.

[0124] In this embodiment, when N is 2, the exponential fitting performed on the transient absorption spectral dynamics curve is a double exponential fitting. The double exponential fitting has two absorption decay intervals. Therefore, it is only necessary to select a dividing point to divide the total absorption decay interval into two intervals: a fast decay interval and a slow decay interval. Each interval corresponds to a set of initial parameters. In this case, only the largest weighted curvature value in the weighted curvature value sequence needs to be selected as the dividing point. Therefore, when N equals 2, it is not necessary to sort the weighted curvature value sequence; the largest weighted curvature value can be directly selected to simplify the division process.

[0125] In one feasible embodiment, to improve the accuracy of dividing the total absorption attenuation interval into a corresponding number of absorption attenuation intervals, when N is 3, the above-mentioned selection of the first N-1 weighted curvature values ​​in descending order from the weighted curvature value sequence, and the division of the total absorption attenuation interval into N absorption attenuation intervals corresponding to the curve fitting order based on the sampling points in the transient absorption spectral dynamics curve corresponding to the first N-1 weighted curvature values, may include the following steps. (See reference...) Figure 5 , Figure 5 This is a flowchart illustrating a method for dividing an absorption attenuation interval according to an embodiment of this application.

[0126] S501: Select the first two weighted curvature values ​​in descending order from the weighted curvature value sequence; the first two weighted curvature values ​​include the first weighted curvature value and the second weighted curvature value;

[0127] S502: Determine the first sampling point in the transient absorption spectral dynamics curve corresponding to the first weighted curvature value, and the second sampling point in the transient absorption spectral dynamics curve corresponding to the second weighted curvature value;

[0128] S503: Based on the first sampling point and the second sampling point, the total absorption attenuation interval is divided into a first interval from the initial absorption point to the first sampling point, a second interval from the first sampling point to the second sampling point, and a third interval from the second sampling point to the absorption attenuation termination point.

[0129] In this embodiment, N is set to 3. Therefore, two dividing points are needed to divide the total absorption attenuation interval into three intervals: the first interval, the second interval, and the third interval. In this embodiment, a set of parameters is determined for each of the first, second, and third intervals, and all three sets of parameters are used as the initial parameters for the transient absorption spectral dynamics curve. In this embodiment, the weighted curvature value sequence can be arranged in descending order of weighted curvature value, and the first two weighted curvature values ​​can be selected from the arranged sequence. Alternatively, the weighted curvature value sequence can be left unsorted, and the maximum value in the current sequence can be selected sequentially until two weighted curvature values ​​are selected.

[0130] In one feasible embodiment, to improve the simplicity of dividing the absorption attenuation interval when N equals 3, the above method may further include the following steps before selecting the first two weighted curvature values ​​in descending order from the weighted curvature value sequence. For details, please refer to... Figure 6 , Figure 6 This is a flowchart illustrating a screening method provided in an embodiment of this application.

[0131] S601: Obtain the first average of all weighted curvature values ​​in the weighted curvature value sequence, and the second average of all second derivatives;

[0132] S602: Select several first target weighted curvature values ​​from the weighted curvature value sequence to form a first target weighted curvature value sequence; the first target weighted curvature value is greater than or equal to the first average value, and the second derivative of the target weighted curvature value at the same sampling point is greater than or equal to the second average value;

[0133] Selecting the first two weighted curvature values ​​from the weighted curvature value sequence in descending order can include:

[0134] S603: Select the first two first target weighted curvature values ​​in descending order from the first target weighted curvature value sequence.

[0135] To avoid the selected dividing points clearly not conforming to the physical laws of the transient absorption spectral dynamics curve, this embodiment of the application removes weighted curvature values ​​that do not conform to the physical constraints of the transient absorption spectral dynamics curve before selecting weighted curvature values ​​in descending order. This reduces the computational load when selecting weighted curvature values. Specifically, weighted curvature values ​​in the weighted curvature value sequence whose first derivative is greater than the average of the first derivatives in the sequence and whose second derivative is greater than the average of the second derivatives in the sequence are selected as the first target weighted curvature values ​​after being screened for the physical constraints of the transient absorption spectral dynamics curve. All the first target weighted curvature values ​​obtained after screening are combined into a first target weighted curvature value sequence, which is then used to select the first two first target weighted curvature values ​​in descending order from this first target weighted curvature value sequence.

[0136] In one feasible embodiment, to avoid selecting two incorrectly chosen dividing points when N equals 3, such that adjacent points are too close and located within the same dividing region, the above method may further include:

[0137] In the first target weighted curvature value sequence, if the time difference between adjacent first target weighted curvature values ​​is less than the second preset threshold, only the maximum value among adjacent first target weighted curvature values ​​is retained to obtain the second target weighted curvature value sequence; the second preset threshold is a threshold set based on the length of the total absorption attenuation interval.

[0138] Selecting the first two first target weighted curvature values ​​from the first target weighted curvature value sequence in descending order can include:

[0139] The first two weighted curvature values ​​of the second objective are selected in descending order from the sequence of weighted curvature values ​​of the second objective.

[0140] To avoid the selected two dividing points being too close together, resulting in unreasonable intervals, this embodiment of the application sets a second preset threshold. The first target weighted curvature value sequence obtained after the first screening is then screened again. The screening condition in this step is set so that the time difference between adjacent first target weighted curvature values ​​is less than the second preset threshold. In this case, the screening mechanism is triggered, and only the maximum value among adjacent first target weighted curvature values ​​is retained. Finally, the second target weighted curvature value sequence is obtained after screening, thus avoiding the selection of two dividing points being too close, which could lead to unreasonable absorption attenuation intervals. Furthermore, the second preset threshold in this embodiment of the application can be specifically set to 8% to 12% of the length of the total absorption attenuation interval.

[0141] S105: Based on the quantitative relationship between the absorption intensity at the starting point of each absorption attenuation interval in the exponential fitting model and the absorption intensity attenuating to 1 / e of the corresponding starting point of the interval, determine N sets of parameters corresponding to N absorption attenuation intervals as initial parameters.

[0142] Based on the above formula (1) in this embodiment, it can be determined that when the absorption intensity decays to 1 / e, it is a special point for exponential fitting in this embodiment, and the value of t at this time is... Therefore, in Using the average of all data points from the decay termination point to the final point of the entire transient absorption spectral dynamics curve as the steady-state value, the initial amplitude parameter... It can be determined that, The initial parameters for exponential fitting of the transient absorption spectral dynamics curve can be determined based on the time difference between the current value of t and the time corresponding to the initial absorption point, which facilitates the optimization and confirmation of the final parameters for exponential fitting.

[0143] In one feasible embodiment, to ensure the accurate confirmation of the initial parameters by using each set of parameters within each absorption attenuation interval as the final initial parameters, the above-mentioned quantization relationship based on the absorption intensity at the starting point of each absorption attenuation interval in the exponential fitting model, which decays to 1 / e of the absorption intensity at the corresponding starting point of the interval, determines N sets of parameters corresponding to N absorption attenuation intervals as initial parameters. This can include the following steps. (See reference...) Figure 7 , Figure 7 This is a flowchart illustrating a method for determining initial parameters within an absorption attenuation range, as provided in an embodiment of this application.

[0144] S701: Based on the difference between the absorption intensity at the start of each absorption attenuation interval and the absorption intensity at the end of the interval, determine the target absorption intensity value in each absorption attenuation interval that the absorption intensity decreases to 1 / e times the absorption intensity at the start of the interval.

[0145] S702: Use the target absorption intensity value in each absorption attenuation interval as the initial amplitude parameter in the corresponding absorption attenuation interval;

[0146] S703: Determine the target sampling point corresponding to the target absorption intensity value within each absorption attenuation interval;

[0147] S704: Use the time difference between the target sampling point and the initial absorption point in each absorption attenuation interval as the initial time parameter in the corresponding absorption attenuation interval.

[0148] S705: Use the initial amplitude parameter and initial time parameter corresponding to each absorption attenuation interval as the initial parameters.

[0149] In this embodiment, a target absorption intensity value is determined where the absorption intensity decays to 1 / e times the absorption intensity at the start of each absorption attenuation interval. Then, the target absorption intensity value in each absorption attenuation interval is used as the initial amplitude parameter in the corresponding absorption attenuation interval to determine the initial amplitude parameter in each absorption attenuation interval. The time difference between the target sampling point and the initial absorption point in each absorption attenuation interval is used as the initial time parameter in the corresponding absorption attenuation interval to determine the initial time parameter in each absorption attenuation interval, so as to smoothly determine the initial parameters of the transient absorption spectral dynamics curve.

[0150] In one feasible embodiment, to achieve a comprehensive fit to the transient absorption spectral dynamics curve, the above method may further include the following steps. (See reference...) Figure 8 , Figure 8 This is a flowchart illustrating a response stage fitting method provided in an embodiment of this application.

[0151] S801: Obtain the starting point of the response time of the transient absorption spectral dynamics curve;

[0152] S802: Determine the transient absorption spectral dynamics curve segment located between the start of the response time and the initial absorption point, as the response interval of the transient absorption spectral dynamics curve;

[0153] S803: Obtain the extreme values ​​of absorption intensity in the transient absorption spectral dynamics curve within the response interval, and use them as the initial amplitude parameters for the response stage;

[0154] S804: Use the midpoint of the response interval as the initial center parameter of the response phase;

[0155] S805: Use the time difference of the response interval as the initial width parameter of the response phase;

[0156] S806: Use the initial amplitude parameter, initial center parameter, and initial width parameter of the response phase as the initial parameters of the Gaussian function fitting model of the instrument response phase.

[0157] In this embodiment, the transient absorption spectral dynamics curve of the instrument response stage is fitted using a Gaussian function fitting model. Therefore, the initial parameters of the Gaussian function fitting model include the initial amplitude parameter, initial center parameter, and initial width parameter of the response stage. The obtained initial parameters of the Gaussian function fitting model are substituted into the corresponding Gaussian function fitting model, and the actual parameters are obtained through subsequent optimization based on the initial parameters, thereby improving the efficiency of curve fitting.

[0158] By applying the initial parameter determination method for transient absorption spectral dynamics curves provided in this application, and by obtaining the initial absorption point and absorption attenuation termination point of the transient absorption spectral dynamics curve, the entire absorption attenuation segment of the transient absorption spectral dynamics curve can be determined. By performing first and second derivatives on the transient absorption spectral dynamics curve, and in the case of multi-order exponential fitting, the obtained first and second derivatives are used to determine the dividing points. Using the first derivative avoids including the attenuation termination interval, which tends towards stability, in the transient absorption spectral dynamics curve, while using the second derivative ensures that the selected dividing points are at the absorption intensities. The high rate of change of intensity improves the accuracy of the division point selection and enhances the accuracy of dividing multiple absorption decay intervals with different absorption decay rates within the entire absorption decay segment of the transient absorption spectral dynamics curve based on this division point. Based on the quantification relationship between the absorption intensity at the start of each absorption decay interval in the exponential fitting model and the absorption intensity at the corresponding start of the interval decaying to 1 / e, N sets of parameters corresponding to N absorption decay intervals are determined as initial parameters. This enables the automatic determination of the initial parameters of the transient absorption spectral dynamics curve, improving the fitting efficiency and accuracy of the transient absorption spectral dynamics curve.

[0159] Furthermore, in this embodiment, the average absorption intensity in the transient absorption spectral dynamics curve is used as a benchmark for comparison with the absorption attenuation termination point in the transient absorption spectral dynamics curve to determine the initial absorption point, thus accurately obtaining the initial absorption point of the transient absorption spectral dynamics curve. By smoothing the obtained original transient absorption spectral dynamics curve, noise interference on the original transient absorption spectral dynamics curve can be reduced without affecting the main dynamic characteristics, thereby achieving noise suppression and improving the accuracy of analysis and processing of the transient absorption spectral dynamics curve. By pre-screening and removing some weighted curvature values ​​that do not meet the conditions, the excessive amount of data avoids increasing the computational burden. When N equals 2, it is not necessary to sort the weighted curvature value sequence; the largest weighted curvature value can be directly selected, simplifying the division steps. When N is 3, the first N-1 weighted curvature values ​​are selected in descending order from the weighted curvature value sequence, and the total absorption attenuation interval is divided into N values ​​corresponding to the curve fitting order, based on the sampling points in the transient absorption spectral dynamics curve corresponding to each of the first N-1 weighted curvature values. The method of dividing the total absorption attenuation interval into a corresponding number of absorption attenuation intervals improves the accuracy of dividing the total absorption attenuation interval into the corresponding number of absorption attenuation intervals. By removing weighted curvature values ​​that do not meet the physical constraints of the transient absorption spectral dynamics curve in advance, the computational load when selecting weighted curvature values ​​can be reduced. By setting a second preset threshold, the first target weighted curvature value sequence obtained after one screening is screened again. The screening condition is set to trigger the screening mechanism when the time difference between adjacent first target weighted curvature values ​​is less than the second preset threshold. At this time, only the maximum value among adjacent first target weighted curvature values ​​is retained, which can avoid the unreasonable division of absorption attenuation intervals due to the distance between the two selected division points being too close. By determining the target absorption intensity value within each absorption attenuation interval, which is 1 / e times the absorption intensity at the beginning of the interval, the initial time parameters within each absorption attenuation interval can be determined, and the initial parameters of the transient absorption spectral dynamics curve can be successfully determined. By substituting the initial parameters of the obtained Gaussian function fitting model into the corresponding Gaussian function fitting model, the actual parameters can be obtained through subsequent optimization based on the initial parameters, thereby improving the efficiency of curve fitting.

[0160] To make the method for determining the initial parameters of the transient absorption spectral dynamics curve mentioned above in the embodiments of this application easier to understand, this application also provides a specific application scenario embodiment, which specifically includes the following steps.

[0161] Signal preprocessing:

[0162] The signal preprocessing in this embodiment involves processing the original transient absorption spectrum dynamics curve. Smoothing is performed using the Savitzky-Golay filtering algorithm (the Savitzky-Golay filtering algorithm is the Savitzky-Golay filtering algorithm), as shown in the following formula (3):

[0163] (3);

[0164] in, Here, represents the polynomial fitting coefficients, and m is the window size for smoothing. The absorption intensity is shown in the transient absorption spectral dynamics curve after smoothing.

[0165] Signal pattern recognition and extreme value detection:

[0166] The signal pattern recognition in this embodiment identifies the overall trend of the transient absorption spectral dynamics curve. This overall trend can be either an initial increase followed by an overall decrease, or an initial decrease followed by an overall increase. Furthermore, extremum detection uses the detected extrema as the initial absorption point based on the overall trend of the curve. Specifically, the signal pattern recognition and extremum detection in this embodiment calculate the average value of the transient absorption spectral dynamics curve. With the last value Automatically identify the signal pattern based on the above average value. Less than the last value When the transient absorption spectral dynamics curve is at that time, the overall trend is determined to be a DROP signal, meaning the curve initially decreases and then increases; while the above average value... Greater than the last value When this occurs, the overall trend of the transient absorption spectral dynamics curve is determined to be a RISE signal, meaning the curve initially increases and then decreases. The aforementioned final values... The determination method can be specifically set to satisfy the condition at 5 consecutive sampling points. In this case, if the curve has reached a stable state, then the first sampling point among the five consecutive sampling points that meets the conditions can be determined as the time corresponding to the termination point of absorption attenuation. .

[0167] Then, based on the overall trend of the transient absorption spectral dynamics curve, the selection strategy for the extreme values ​​in the transient absorption spectral dynamics curve is determined, and the corresponding initial absorption point selection strategy is shown in the following formula (4):

[0168] (4);

[0169] in, This refers to the time corresponding to the initial absorption point. Specifically, when the overall trend of the transient absorption spectral dynamics curve is a DROP signal, the minimum value in the transient absorption spectral dynamics curve is selected as the initial absorption point; when the overall trend of the transient absorption spectral dynamics curve is a RISE signal, the maximum value in the transient absorption spectral dynamics curve is selected as the initial absorption point. .

[0170] Obtain the first and second derivatives of the transient absorption spectral dynamics curve:

[0171] In this embodiment of the application, after obtaining the first derivative of the transient absorption spectral dynamics curve, the obtained first derivative can be normalized, as shown in the following formula (5):

[0172] (5);

[0173] in, This represents the first derivative of the normalized transient absorption spectral dynamics curve. This represents the maximum absolute value of the first derivative of the transient absorption spectral dynamics curve. Similarly, in this embodiment, after obtaining the second derivative of the transient absorption spectral dynamics curve, the obtained second derivative can be normalized, as shown in the following formula (6):

[0174] (6);

[0175] in, This represents the second derivative of the transient absorption spectral dynamics curve after normalization. The maximum value among the absolute values ​​of the first derivative of the transient absorption spectral dynamics curve.

[0176] Obtain the initial parameters during the instrument response phase:

[0177] Before obtaining the initial parameters for the absorption decay phase of the transient absorption spectral kinetics curve, the initial parameters for the function of the instrument response phase can be determined first. Based on the global extreme point of the transient absorption spectral kinetics curve determined above, which is the initial absorption point of the transient absorption spectral kinetics curve... The embodiments of this application will start from the excitation time starting point. to the initial absorption point The time interval is defined as the effective interval of the instrument response. Typically, Gaussian fitting is used for fitting the instrument response phase. Therefore, there are three main initial parameters for fitting the instrument response phase: initial amplitude parameter, initial center parameter, and initial width parameter. Among these, the initial width parameter is the key parameter for fitting the instrument response phase. The fitting method for the three parameters is as follows:

[0178] Amplitude parameters :Pick to The maximum absolute value of the absorption intensity within the interval is used as the initial amplitude parameter of the Gaussian function fitting model;

[0179] Center parameters :Pick to The center point of the interval (i.e., the midpoint between the start and end times of the interval and the end time of the interval) is used as the initial center parameter of the Gaussian function fitting model;

[0180] Width parameter :Pick to The time width of the interval (i.e., the difference between the time corresponding to the maximum absolute value of the absorption intensity and the starting time of the interval) is used as the initial width parameter of the Gaussian function fitting model.

[0181] Divide the absorption attenuation intervals and determine the parameters within each interval as initial parameters:

[0182] For exponential fitting of transient absorption spectral kinetic curves, single-exponential, double-exponential, and triple-exponential fitting are commonly used. These correspond to dividing the total absorption attenuation interval into one, two, and three intervals, respectively. In other words, the division of the fast and slow intervals of the transient absorption spectral kinetic curve requires calculation based on the order of the exponential fitting. Single-exponential fitting, since it has only one absorption attenuation interval, can directly determine that its absorption attenuation interval is the total absorption attenuation interval, which is the same as the aforementioned... to Within this absorption attenuation range, the amplitude coefficient is estimated using the quantization relationship that the attenuation is reduced to 1 / e of the absorption intensity. Specifically, as shown in the following formula (7):

[0183] (7);

[0184] The initial time parameter is one of the initial parameters corresponding to single exponential fitting. By finding The position is calculated, that is ,in for The corresponding time. And for the steady-state term in the above formula (1). Typically, the attenuation termination point can be used directly. The average value of all absorption intensity data between the final point of the transient absorption spectral dynamics curve and the final point is taken as the steady-state value. .

[0185] For bi-exponential fitting, the embodiments of this application can be referred to. Figure 9 , Figure 9 This is an example diagram of a double-exponential fitting dynamic curve provided in an embodiment of this application. Wherein, 0 to... This represents the response phase of the kinetic curve. to For the decay phase of the dynamic curve, in the embodiments of this application, it is necessary to... to The interval is divided into two regions: fast decay and slow decay. Based on the decay characteristics of the transient absorption spectral kinetic curve, the kinetic decay process typically proceeds as fast decay – slow decay – even slower decay; therefore, it is necessary to... to Find a dividing point within the interval. ,Will to The interval is considered a fast decay interval. to The interval is considered a slow decay interval. The methods for determining the location at a given time and estimating the corresponding initial parameters are as follows:

[0186] First, the first and second derivatives of the smoothed transient absorption spectral dynamics curve are determined, and then normalized.

[0187] Then, at the initial absorption point of the transient absorption spectral dynamics curve. and attenuation termination point Between these points, find the set of local maxima of the normalized second derivative, as shown in the following formula (8):

[0188] (8);

[0189] In this context, the time sampling point in T represents the moment when the curve's curvature is at its maximum, which typically corresponds to a transition in the dynamic phase. for The value of the second derivative of the corresponding transient absorption spectral dynamics curve.

[0190] Next, divide the points. The determination of the value is based on the second derivative of the transient absorption spectral dynamics curve obtained after normalization, and the first derivative of the transient absorption spectral dynamics curve obtained after normalization, and a weighted average is applied, as shown in the following formula (9):

[0191] (9);

[0192] in, This is the weighted curvature obtained after weighting, and its specific value is the weighted curvature value.

[0193] The sampling point corresponding to the largest weighted curvature value is taken as the dividing point, as shown in the following formula (10):

[0194] (10);

[0195] Finally, the initial parameters for the double exponential fit are determined. The algorithm for determining the initial parameters for the single exponential fit can be referenced. Within each interval, the initial amplitude parameters are determined using the quantization relationship where the absorption intensity decays to 1 / e. and ) and initial time parameters ( and Specifically, as shown in formulas (11) and (12) below:

[0196] (11);

[0197] (12);

[0198] Find the initial amplitude parameter corresponding to the fast and slow decay intervals. and Then, find the time corresponding to the initial amplitude parameter within the corresponding interval. The corresponding time is , The corresponding time is Through calculation and The initial time parameters can then be calculated. and .

[0199] For a three-exponential fit, there are three different decay processes involved, therefore in to There are two dividing points within the interval. and .in , T The calculation methods are the same as those used in the double exponential fitting process. However, for... and The process of determining the location first involves retaining only those that satisfy... ≥ and ≥ The points are selected as candidate points, where, For self to The first average of all weighted curvature values ​​within the interval. For self to The second average of all second derivatives within the interval is given. Simultaneously, a minimum interval constraint is set, requiring the time interval between any two candidate points to be less than δ, where δ is the average of all second derivatives within the interval. to 10% of the interval length is used to scan each candidate point in chronological order. If the minimum interval constraint is not met, only those points are retained. The largest candidate point. After two rounds of filtering, the top two are automatically selected in descending order. corresponding time and At the same time, according to Less than The constraint conditions are arranged to divide the points. After determining the two division points, the method for determining the parameters of the three absorption attenuation intervals is consistent with the above-mentioned double exponential fitting calculation method, that is, the current initial amplitude parameter is determined by the quantization relationship of attenuation to 1 / e of the absorption intensity. , and ) and the current initial time parameters ( , and ).

[0200] The fitting results obtained using the single-exponential fitting method, double-exponential fitting method, and triple-exponential fitting method in the embodiments of this application can be used as a reference. Figures 10 to 15 , Figures 10 to 12 These are example diagrams of single-exponential fitting results, double-exponential fitting results, and triple-exponential fitting results of a dynamic curve provided in the embodiments of this application. Figures 13 to 15 These are example graphs showing the single-exponential fitting result, the double-exponential fitting result, and the triple-exponential fitting result of another dynamic curve provided in the embodiments of this application. According to the above... Figures 10 to 15 It can be determined that the fitting result of the triple-exponential fit is better than that of the double-exponential fit, and the fitting result of the double-exponential fit is better than that of the single-exponential fit. Furthermore, it should be noted that the above... Figures 9 to 15 The horizontal axis in the figure is in picoseconds, and the vertical axis is in millimeters of density.

[0201] This application's real-time example introduces an initial parameter determination method based on derivative-curvature characteristics, realizing fully automated calculation of initial parameters for fitting the exponential decay of transient absorption spectral dynamics. This overcomes the problems of traditional methods, such as high dependence on human experience, sensitivity to initial values, and unstable fitting. It also has the following significant technical advantages: automated initial parameter estimation, improving fitting convergence and reliability; enhanced algorithm robustness and noise resistance; support for the scalability of multi-exponential models, making it suitable for complex dynamic process analysis; and improved efficiency in high-throughput data processing and intelligent analysis.

[0202] Figure 16 This is a schematic diagram of the structure of a device for determining the initial parameters of a transient absorption spectral dynamics curve provided in an embodiment of this application. Figure 16 As shown, the device may include:

[0203] The feature point acquisition module 1601 is used to acquire the initial absorption point and the absorption attenuation termination point of the transient absorption spectral dynamics curve; the absorption attenuation termination point is the first sampling point in the sampling interval where the rate of change of absorption intensity is continuously lower than a first preset threshold in the transient absorption spectral dynamics curve.

[0204] The total absorption attenuation interval determination module 1602 is used to determine the curve segment in the transient absorption spectral dynamics curve located between the initial absorption point and the absorption attenuation termination point as the total absorption attenuation interval.

[0205] The weighted curvature value sequence acquisition module 1603 is used to perform weighted processing on the first and second derivatives of the transient absorption spectrum dynamic curve to obtain a weighted curvature value sequence.

[0206] The absorption attenuation interval division module 1604 is used to select the first N-1 weighted curvature values ​​in descending order from the weighted curvature value sequence, and divide the total absorption attenuation interval into N absorption attenuation intervals corresponding to the curve fitting order based on the sampling points in the transient absorption spectral dynamics curve corresponding to the first N-1 weighted curvature values; N is a positive integer.

[0207] The initial parameter determination module 1605 is used to determine N sets of parameters corresponding to N absorption attenuation intervals as initial parameters, based on the quantitative relationship between the absorption intensity at the starting point of each absorption attenuation interval in the exponential fitting model and the absorption intensity at the starting point of the corresponding interval decreasing to 1 / e.

[0208] In one embodiment, the initial parameter determination module 1605 described above may include:

[0209] The target absorption intensity value determination unit is used to determine the target absorption intensity value in each absorption attenuation interval, based on the difference between the absorption intensity at the start of the interval and the absorption intensity at the end of the interval, so that the absorption intensity decreases to 1 / e times the absorption intensity at the start of the interval.

[0210] The initial amplitude parameter determination unit is used to take the target absorption intensity value in each absorption attenuation interval as the initial amplitude parameter in the corresponding absorption attenuation interval.

[0211] The target sampling point determination unit is used to determine the target sampling point corresponding to the target absorption intensity value within each absorption attenuation interval.

[0212] The initial time parameter determination unit is used to take the time difference between the target sampling point and the initial absorption point in each absorption attenuation interval as the initial time parameter in the corresponding absorption attenuation interval.

[0213] The initial parameter determination unit is used to take the initial amplitude parameter and initial time parameter corresponding to each absorption attenuation interval as the initial parameters.

[0214] In one embodiment, N can be set to 2, and the absorption attenuation interval division module 1604 may include:

[0215] The absorption attenuation interval division unit is used to select the maximum weighted curvature value in the weighted curvature value sequence, and divide the total absorption attenuation interval into an interval from the initial absorption point to the sampling point and an interval from the sampling point to the absorption attenuation termination point based on the sampling point in the transient absorption spectral dynamics curve corresponding to the maximum weighted curvature value.

[0216] In one embodiment, N can be set to 3, and the absorption attenuation interval division module 1604 can include:

[0217] The weighted curvature value selection unit is used to select the first two weighted curvature values ​​in descending order from the weighted curvature value sequence; the first two weighted curvature values ​​include the first weighted curvature value and the second weighted curvature value;

[0218] The first sampling point and the second sampling point determination unit is used to determine the first sampling point in the transient absorption spectral dynamics curve corresponding to the first weighted curvature value, and the second sampling point in the transient absorption spectral dynamics curve corresponding to the second weighted curvature value.

[0219] The three-interval division unit is used to divide the total absorption attenuation interval into a first interval from the initial absorption point to the first sampling point, a second interval from the first sampling point to the second sampling point, and a third interval from the second sampling point to the absorption attenuation termination point, based on the first sampling point and the second sampling point.

[0220] In one embodiment, the absorption attenuation interval division module 1604 may further include:

[0221] The average value acquisition unit is used to acquire the first average value of all weighted curvature values ​​in the weighted curvature value sequence, and the second average value of all second derivatives;

[0222] The first target weighted curvature value filtering unit is used to filter a number of first target weighted curvature values ​​from the weighted curvature value sequence as the first target weighted curvature value sequence; the first target weighted curvature value is greater than or equal to the first average value, and the second derivative of the target weighted curvature value corresponding to the same sampling point is greater than or equal to the second average value;

[0223] The weighted curvature value selection unit may include:

[0224] The first target weighted curvature value selection sub-unit is used to select the first two first target weighted curvature values ​​in descending order from the first target weighted curvature value sequence.

[0225] In one embodiment, the absorption attenuation interval division module 1604 may further include:

[0226] The second target weighted curvature value sequence filtering unit is used to filter the second target weighted curvature value sequence by retaining only the maximum value among adjacent first target weighted curvature values ​​when the time difference between adjacent first target weighted curvature values ​​is less than a second preset threshold. The second preset threshold is a threshold set based on the length of the total absorption attenuation interval.

[0227] The first target weighted curvature value selection sub-unit may include:

[0228] The second target weighted curvature value selection sub-unit is used to select the first two second target weighted curvature values ​​in descending order from the second target weighted curvature value sequence.

[0229] In one embodiment, the weighted curvature value sequence acquisition module 1603 described above may include:

[0230] The local second derivative extremum selection unit is used to select several local second derivative extrema in the total absorption attenuation interval;

[0231] The weighted curvature value sequence acquisition unit is used to perform weighted processing on the local second derivative extrema and the first derivative under the same time sequence to obtain a weighted curvature value sequence.

[0232] In one embodiment, the device for determining the initial parameters of the transient absorption spectral dynamics curve may further include:

[0233] The raw curve acquisition module is used to acquire the raw transient absorption spectral dynamics curve;

[0234] The smoothing unit is used to smooth the original transient absorption spectral dynamics curve to obtain the transient absorption spectral dynamics curve.

[0235] In one embodiment, the device for determining the initial parameters of the transient absorption spectral dynamics curve may further include:

[0236] The response time start point acquisition module is used to acquire the response time start point of the transient absorption spectral dynamics curve;

[0237] The response interval determination module is used to determine the transient absorption spectral dynamics curve segment located between the start of the response time and the initial absorption point, as the response interval of the transient absorption spectral dynamics curve;

[0238] The initial amplitude parameter determination module for the response stage is used to obtain the extreme values ​​of absorption intensity in the transient absorption spectrum dynamics curve within the response interval, which are used as the initial amplitude parameters for the response stage.

[0239] The initial center parameter determination module is used to take the midpoint of the response interval as the initial center parameter of the response phase.

[0240] The initial width parameter determination module is used to use the time difference of the response interval as the initial width parameter of the response phase.

[0241] The initial parameter determination module for the response phase is used to take the initial amplitude parameter, the initial center parameter, and the initial width parameter of the response phase as the initial parameters of the Gaussian function fitting model for the instrument response phase.

[0242] In one embodiment, the initial absorption point of the transient absorption spectral dynamics curve acquired in the feature point acquisition module 1601 can be configured to include:

[0243] Obtain the average absorption intensity of the transient absorption spectral dynamics curve;

[0244] If the absorption intensity at the absorption attenuation termination point is greater than the average absorption intensity, the sampling point corresponding to the minimum absorption intensity in the transient absorption spectral kinetic curve is selected as the initial absorption point.

[0245] When the absorption intensity value at the absorption attenuation termination point is less than or equal to the average absorption intensity, the sampling point corresponding to the maximum absorption intensity in the transient absorption spectral kinetic curve is selected as the initial absorption point.

[0246] The device for determining the initial parameters of a transient absorption spectral dynamics curve provided in this application includes a feature point acquisition module 1601, used to acquire the initial absorption point and the absorption attenuation termination point of the transient absorption spectral dynamics curve; the absorption attenuation termination point is the first sampling point in the sampling interval where the rate of change of absorption intensity is continuously lower than a first preset threshold in the transient absorption spectral dynamics curve; an absorption attenuation total interval determination module 1602, used to determine the curve segment in the transient absorption spectral dynamics curve located between the initial absorption point and the absorption attenuation termination point as the absorption attenuation total interval; and a weighted curvature value sequence acquisition module 1603, used to calculate the first and second derivatives of the transient absorption spectral dynamics curve. The values ​​are weighted to obtain a weighted curvature value sequence; the absorption attenuation interval division module 1604 is used to select the first N-1 weighted curvature values ​​in descending order from the weighted curvature value sequence, and divide the total absorption attenuation interval into N absorption attenuation intervals corresponding to the curve fitting order based on the sampling points in the transient absorption spectral dynamics curve corresponding to the first N-1 weighted curvature values; N is a positive integer; the initial parameter determination module 1605 is used to determine N sets of parameters corresponding to the N absorption attenuation intervals as initial parameters based on the quantization relationship of the absorption intensity at the starting point of each absorption attenuation interval in the exponential fitting model and the absorption intensity at the starting point of the corresponding interval decaying to 1 / e.

[0247] This application embodiment, by obtaining the initial absorption point and absorption attenuation termination point of the transient absorption spectral dynamics curve, can determine the entire absorption attenuation segment of the transient absorption spectral dynamics curve. By performing first and second derivatives on the transient absorption spectral dynamics curve, and using the obtained first and second derivatives in multi-order exponential fitting, the dividing point is determined. Using the first derivative avoids including the attenuation termination interval, which tends to be stable, in the transient absorption spectral dynamics curve. Using the second derivative ensures that the selected dividing point is the point with a large rate of change of absorption intensity, improving the accuracy of the dividing point selection. Furthermore, it improves the accuracy of dividing multiple absorption attenuation intervals with different absorption attenuation rates within the entire absorption attenuation segment of the transient absorption spectral dynamics curve based on this dividing point. Based on the quantization relationship of absorption intensity attenuating to 1 / e of the absorption intensity at the initial absorption point in the exponential fitting model, the initial parameters of each absorption attenuation interval are determined. These initial parameters enable automatic determination of the initial parameters of the transient absorption spectral dynamics curve, improving the fitting efficiency and accuracy of the transient absorption spectral dynamics curve.

[0248] Figure 17 A schematic diagram of the structure of the device for determining the initial parameters of the transient absorption spectral dynamics curve provided in an embodiment of this application is shown.

[0249] The device for determining the initial parameters of the transient absorption spectral dynamics curve may include a processor 1701 and a memory 1702 storing computer program instructions.

[0250] Specifically, the processor 1701 may include a central processing unit (CPU), an application specific integrated circuit (ASIC), or one or more integrated circuits that can be configured to implement the embodiments of this application.

[0251] Memory 1702 may include mass storage for data or instructions. For example, and not limitingly, memory 1702 may include a hard disk drive (HDD), floppy disk drive, flash memory, optical disk, magneto-optical disk, magnetic tape, or Universal Serial Bus (USB) drive, or a combination of two or more of these. In one instance, memory 1702 may include removable or non-removable (or fixed) media, or memory 1702 may be non-volatile solid-state memory. Memory 1702 may be internal or external to the integrated gateway disaster recovery device.

[0252] Memory 1702 may include read-only memory (ROM), random access memory (RAM), disk storage media device, optical storage media device, flash memory device, electrical, optical, or other physical / tangible memory storage device. Thus, generally, memory includes one or more tangible (non-transitory) computer-readable storage media (e.g., memory devices) encoded with software including computer-executable instructions, and when the software is executed (e.g., by one or more processors), it is operable to perform the operations described with reference to the method according to one aspect of this disclosure.

[0253] Processor 1701 reads and executes computer program instructions stored in memory 1702 to achieve... Figure 1 The method for determining the initial parameters of the transient absorption spectral dynamics curve in the illustrated embodiment.

[0254] In one example, the device for determining the initial parameters of the transient absorption spectral dynamics curve may also include a communication interface 1703 and a bus 1704. For example, Figure 17 As shown, the processor 1701, memory 1702, and communication interface 1703 are connected through bus 1704 and complete communication with each other.

[0255] The communication interface 1703 is mainly used to realize communication between various modules, devices, units and / or equipment in the embodiments of this application.

[0256] Bus 1704 includes hardware, software, or both, that couples components of an online data traffic metering device together. For example, and not as a limitation, the bus may include an Accelerated Graphics Port (AGP) or other graphics bus, an Extended Industry Standard Architecture (EISA) bus, a Front Side Bus (FSB), a Hyper Transport (HT) interconnect, an Industry Standard Architecture (ISA) bus, an Infinite Bandwidth Interconnect, a Low Pin Count (LPC) bus, a memory bus, a Microchannel Architecture (MCA) bus, a Peripheral Component Interconnect (PCI) bus, a PCI-Express (PCI-X) bus, a Serial Advanced Technology Attachment (SATA) bus, a Video Electronics Standards Association Local (VLB) bus, or other suitable buses, or combinations of two or more of these. Where appropriate, bus 1704 may include one or more buses. Although specific buses are described and illustrated in embodiments of this application, this application contemplates any suitable bus or interconnect.

[0257] Furthermore, in conjunction with the method for determining the initial parameters of the transient absorption spectral dynamics curve in the above embodiments, this application embodiment can provide a computer storage medium for implementation. This computer storage medium stores computer program instructions; when these computer program instructions are executed by a processor, they implement any of the methods for determining the initial parameters of the transient absorption spectral dynamics curve in the above embodiments.

[0258] This application also provides a computer program product, including a computer program that, when executed by a processor, implements a method for determining the initial parameters of any of the transient absorption spectral dynamics curves described in the above embodiments.

[0259] It should be clarified that this application is not limited to the specific configurations and processes described above and shown in the figures. For the sake of brevity, detailed descriptions of known methods are omitted here. In the above embodiments, several specific steps are described and shown as examples. However, the method process of this application is not limited to the specific steps described and shown. Those skilled in the art can make various changes, modifications, and additions, or change the order of steps, after understanding the spirit of this application.

[0260] The functional blocks shown in the above-described block diagram can be implemented as hardware, software, firmware, or a combination thereof. When implemented in hardware, they can be, for example, electronic circuits, application-specific integrated circuits (ASICs), appropriate firmware, plug-ins, function cards, etc. When implemented in software, the elements of this application are programs or code segments used to perform the required tasks. Programs or code segments can be stored on a machine-readable medium or transmitted over a transmission medium or communication link via data signals carried on a carrier wave. "Machine-readable medium" can include any medium capable of storing or transmitting information. Examples of machine-readable media include electronic circuits, semiconductor memory devices, read-only memory (ROM), flash memory, erasable read-only memory (EROM), floppy disks, compact disc read-only memory (CD-ROM), optical disks, hard disks, fiber optic media, radio frequency (RF) links, etc. Code segments can be downloaded via computer networks such as the Internet, intranets, etc.

[0261] It should also be noted that the exemplary embodiments mentioned in this application describe methods or systems based on a series of steps or apparatus. However, this application is not limited to the order of the above steps; that is, the steps can be performed in the order mentioned in the embodiments, or in a different order, or several steps can be performed simultaneously.

[0262] The aspects of this disclosure have been described above with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this disclosure. It should be understood that each block in the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus to produce a machine such that these instructions, executable via the processor of the computer or other programmable data processing apparatus, enable the implementation of the functions / actions specified in one or more blocks of the flowchart illustrations and / or block diagrams. Such a processor can be, but is not limited to, a general-purpose processor, a special-purpose processor, a special application processor, or a field-programmable logic circuit. It is also understood that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can also be implemented by special-purpose hardware performing the specified functions or actions, or can be implemented by a combination of special-purpose hardware and computer instructions.

[0263] The above description is merely a specific implementation of this application. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, modules, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here. It should be understood that the protection scope of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the protection scope of this application.

Claims

1. A method for determining the initial parameters of a transient absorption spectral dynamics curve, characterized in that, include: Obtain the initial absorption point and the absorption attenuation termination point of the transient absorption spectral dynamics curve; the absorption attenuation termination point is the first sampling point in the sampling interval where the rate of change of absorption intensity is continuously lower than a first preset threshold in the transient absorption spectral dynamics curve. The segment of the transient absorption spectral dynamics curve located between the initial absorption point and the absorption attenuation termination point is defined as the total absorption attenuation interval. The first and second derivatives of the transient absorption spectral dynamics curve are weighted to obtain a weighted curvature value sequence. The first N-1 weighted curvature values ​​are selected from the weighted curvature value sequence in descending order. Based on the sampling points in the transient absorption spectral dynamics curve corresponding to the first N-1 weighted curvature values, the total absorption attenuation interval is divided into N absorption attenuation intervals corresponding to the curve fitting order; N is a positive integer. Based on the absorption intensity at the starting point of each absorption attenuation interval in the exponential fitting model, and the quantization relationship of attenuation to 1 / e of the absorption intensity at the corresponding starting point of the interval, N sets of parameters corresponding to the N absorption attenuation intervals are determined as initial parameters.

2. The method for determining the initial parameters of the transient absorption spectral dynamics curve according to claim 1, characterized in that, The absorption intensity at the starting point of each absorption attenuation interval in the exponential fitting model decays to 1 / e of the absorption intensity at the corresponding starting point of the interval. Based on this quantization relationship, N sets of parameters corresponding to the N absorption attenuation intervals are determined as initial parameters, including: Based on the difference between the absorption intensity at the start of each absorption attenuation interval and the absorption intensity at the end of the interval, the target absorption intensity value is determined to be 1 / e times the absorption intensity at the start of the interval within each absorption attenuation interval. The target absorption intensity value within each absorption attenuation interval is used as the initial amplitude parameter within the corresponding absorption attenuation interval; Determine the target sampling points corresponding to the target absorption intensity values ​​within each absorption attenuation interval; The time difference between the target sampling point and the initial absorption point in each absorption attenuation interval is used as the initial time parameter in the corresponding absorption attenuation interval. The initial amplitude parameter and the initial time parameter corresponding to each absorption attenuation interval are used as the initial parameters.

3. The method for determining the initial parameters of the transient absorption spectral dynamics curve according to claim 1, characterized in that, The value of N is 2; The first N-1 weighted curvature values ​​are selected from the weighted curvature value sequence in descending order. Based on the sampling points in the transient absorption spectral dynamics curve corresponding to each of the first N-1 weighted curvature values, the total absorption attenuation interval is divided into N absorption attenuation intervals corresponding to the curve fitting order, including: The maximum weighted curvature value is selected from the weighted curvature value sequence, and the total absorption attenuation interval is divided into an interval from the initial absorption point to the sampling point and an interval from the sampling point to the absorption attenuation termination point based on the sampling point in the transient absorption spectral dynamics curve corresponding to the maximum weighted curvature value.

4. The method for determining the initial parameters of the transient absorption spectral dynamics curve according to claim 1, characterized in that, The value of N is 3; The first N-1 weighted curvature values ​​are selected from the weighted curvature value sequence in descending order. Based on the sampling points in the transient absorption spectral dynamics curve corresponding to each of the first N-1 weighted curvature values, the total absorption attenuation interval is divided into N absorption attenuation intervals corresponding to the curve fitting order, including: The first two weighted curvature values ​​are selected from the weighted curvature value sequence in descending order; the first two weighted curvature values ​​include a first weighted curvature value and a second weighted curvature value. Determine the first sampling point in the transient absorption spectral dynamics curve corresponding to the first weighted curvature value, and the second sampling point in the transient absorption spectral dynamics curve corresponding to the second weighted curvature value; Based on the first sampling point and the second sampling point, the total absorption attenuation interval is divided into a first interval from the initial absorption point to the first sampling point, a second interval from the first sampling point to the second sampling point, and a third interval from the second sampling point to the absorption attenuation termination point.

5. The method for determining the initial parameters of the transient absorption spectral dynamics curve according to claim 4, characterized in that, Before selecting the first two weighted curvature values ​​in descending order from the weighted curvature value sequence, the method further includes: Obtain the first average value of all weighted curvature values ​​in the weighted curvature value sequence, and the second average value of all the second derivatives; Several first target weighted curvature values ​​are selected from the weighted curvature value sequence to form a first target weighted curvature value sequence; the first target weighted curvature value is greater than or equal to the first average value, and the second derivative of the target weighted curvature value corresponding to the same sampling point is greater than or equal to the second average value; The step of selecting the first two weighted curvature values ​​in descending order from the weighted curvature value sequence includes: The first two first target weighted curvature values ​​are selected in descending order from the first target weighted curvature value sequence.

6. The method for determining the initial parameters of the transient absorption spectral dynamics curve according to claim 5, characterized in that, The method further includes: In the first target weighted curvature value sequence, if the time difference between adjacent first target weighted curvature values ​​is less than a second preset threshold, only the maximum value among the adjacent first target weighted curvature values ​​is retained to obtain the second target weighted curvature value sequence; the second preset threshold is a threshold set based on the length of the total absorption attenuation interval; The step of selecting the first two first target weighted curvature values ​​in descending order from the first target weighted curvature value sequence includes: The first two second target weighted curvature values ​​are selected in descending order from the second target weighted curvature value sequence.

7. The method for determining the initial parameters of the transient absorption spectral dynamics curve according to claim 1, characterized in that, The weighted processing of the first and second derivatives of the transient absorption spectral dynamics curve yields a weighted curvature value sequence, including: Several local second-order derivative extrema are selected within the total absorption attenuation interval; The local second derivative extrema and the first derivative in the same time series are weighted to obtain the weighted curvature value sequence.

8. The method for determining the initial parameters of the transient absorption spectral dynamics curve according to claim 1, characterized in that, The method further includes: Obtain the starting point of the response time of the transient absorption spectral dynamics curve; The transient absorption spectral dynamics curve segment located between the start of the response time and the initial absorption point is determined as the response interval of the transient absorption spectral dynamics curve; The extreme values ​​of absorption intensity in the transient absorption spectral dynamics curve within the response interval are obtained as the initial amplitude parameters for the response stage; The midpoint of the response interval is used as the initial center parameter of the response phase; The time difference of the response interval is used as the initial width parameter of the response phase; The initial amplitude parameter, the initial center parameter, and the initial width parameter of the response phase are used as the initial parameters of the Gaussian function fitting model for the instrument response phase.

9. The method for determining the initial parameters of the transient absorption spectral dynamics curve according to claim 1, characterized in that, The method for obtaining the initial absorption point of the transient absorption spectral dynamics curve includes: Obtain the average absorption intensity of the transient absorption spectral dynamics curve; If the absorption intensity value at the absorption attenuation termination point is greater than the average absorption intensity, the sampling point corresponding to the minimum absorption intensity in the transient absorption spectral dynamics curve is selected as the initial absorption point. If the absorption intensity value at the absorption attenuation termination point is less than or equal to the average absorption intensity, the sampling point corresponding to the maximum absorption intensity in the transient absorption spectral dynamics curve is selected as the initial absorption point.

10. A device for determining the initial parameters of a transient absorption spectral dynamics curve, characterized in that, The device includes: The feature point acquisition module is used to acquire the initial absorption point and the absorption attenuation termination point of the transient absorption spectral dynamics curve; the absorption attenuation termination point is the first sampling point in the sampling interval where the rate of change of absorption intensity is continuously lower than a first preset threshold in the transient absorption spectral dynamics curve. The total absorption attenuation interval determination module is used to determine the curve segment in the transient absorption spectral dynamics curve located between the initial absorption point and the absorption attenuation termination point as the total absorption attenuation interval; The weighted curvature value sequence acquisition module is used to perform weighted processing on the first and second derivatives of the transient absorption spectrum dynamic curve to obtain a weighted curvature value sequence. The absorption attenuation interval division module is used to select the first N-1 weighted curvature values ​​in the weighted curvature value sequence in descending order, and divide the total absorption attenuation interval into N absorption attenuation intervals corresponding to the sampling points in the transient absorption spectral dynamics curve corresponding to the first N-1 weighted curvature values; N is a positive integer. The initial parameter determination module is used to determine N sets of parameters corresponding to the N absorption attenuation intervals as initial parameters, based on the quantization relationship of the absorption intensity at the starting point of each absorption attenuation interval in the exponential fitting model, which is attenuated to 1 / e of the absorption intensity at the corresponding starting point of the interval.

11. A device for determining the initial parameters of a transient absorption spectral dynamics curve, characterized in that, The device includes: a processor and a memory storing computer program instructions; the processor reads and executes the computer program instructions to implement the method for determining the initial parameters of the transient absorption spectral dynamics curve as described in any one of claims 1-9.

12. A computer storage medium, characterized in that, The computer storage medium stores computer program instructions, which, when executed by a processor, implement the method for determining the initial parameters of the transient absorption spectral dynamics curve as described in any one of claims 1-9.

13. A computer program product, characterized in that, Includes a computer program, which, when executed, implements the method for determining the initial parameters of the transient absorption spectral dynamics curve as described in any one of claims 1-9.

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