Method for automatically calibrating small-angle scattering layout parameters

Abstract

The invention relates to a method for automatically calibrating small-angle scattering layout parameters, and belongs to the field of nuclear technology application. The method for automatically calibrating the small-angle scattering layout parameters comprises the following steps: acquiring an estimated center coordinate of a two-dimensional small-angle scattering spectrum of a standard sample by utilizing the central symmetry of two-dimensional scattering intensity distribution; calibrating the estimated center coordinate by optimizing the deviation value of the one-dimensional scattering intensity distribution in the symmetrical direction to obtain a calibrated center coordinate; acquiring a ring integral one-dimensional scattering curve according to the calibration center coordinate; acquiring an abscissa corresponding to a first scattering peak top point in the ring integral one-dimensional scattering curve; and calculating the distance from the standard sample to the detector according to the abscissa corresponding to the top point of the first scattering peak in the ring integral one-dimensional scattering curve and the scattering vector of the first scattering peak of the standard sample. The method can obtain the center coordinates of the two-dimensional scattering spectrum and the distance layout parameters from the sample to the detector, and has the advantages of rapidness, simplicity, high efficiency, high accuracy, high stability and easiness in operation.

Description

Technical Field

[0001] This application relates to the field of nuclear technology applications, and in particular to a method for automatically calibrating small-angle scattering layout parameters. Background Technology

[0002] Small-angle scattering (SAS) is an elastic scattering method whose signal primarily originates from coherent scattering near the incident neutron / X-ray path (typically less than 10°) caused by nanometer to submicron-scale structural inhomogeneities in the sample. Only momentum transfer occurs before and after scattering; there is no energy change. Scattering vectors are typically used in this method. To represent momentum transfer, signals from the reciprocal lattice space are obtained. A parallel-incident neutron / X-ray beam undergoes elastic scattering after passing through a sample, changing its direction of motion. By measuring the scattering intensity in different directions using a two-dimensional position-sensitive detector, a two-dimensional small-angle scattering spectrum can be obtained. For scattering vector The dependency relationship can reflect the mesoscale spatial structure within the sample. For two-dimensional... The data is processed to obtain a one-dimensional scattering curve I(q)-q. The structural information such as the content, size distribution, correlation length, and fractal dimension of the scatterers in the sample can be derived through data inversion.

[0003] Scattering vector The magnitude of θ can be expressed as q = 4πsinθ / λ, where θ is half the scattering angle and λ is the wavelength of the neutron / X-ray. In a neutron / X-ray scattering experiment, the wavelength λ is usually known. To obtain an effective I(q)-q curve, the key is to accurately calculate the θ value corresponding to different pixel positions on the detector. Small-angle scattering geometry satisfies the paraxial approximation, and sinθ can be calculated using geometric relationships: In the formula, d is the distance from a pixel on the detector to the center of the two-dimensional scattering spectrum, and SDD is the distance from the sample to the detector. Therefore, the key to q-value calibration lies in determining the center of the two-dimensional scattering spectrum and obtaining the distance from the sample to the detector.

[0004] Currently, the common method is to use structurally stable standard samples with known small-angle scattering characteristic peak q-values ​​(such as silver behenate powder and ox tendon) for calibration experiments. However, in obtaining the coordinates of the center of the two-dimensional scattering spectrum and the distance from the sample to the detector from the experimental data of the standard samples, traditional analysis methods rely on manual processing by experimenters using specialized software. This requires experimenters to have extensive processing experience and inevitably introduces random human errors. Furthermore, the reliance on human judgment and lack of timeliness of manual processing methods make it difficult to meet the requirements of new demands such as ease of operation (user-friendly) and online real-time analysis. Summary of the Invention

[0005] The purpose of this application is to provide a method for automatically calibrating small-angle scattering layout parameters. This method can automatically process and obtain spectrometer layout parameters that are indispensable for subsequent processing of experimental sample data, such as the center coordinates of the two-dimensional scattering spectrum and the distance from the sample to the detector. It has the advantages of being fast, simple, efficient, accurate, stable, and easy to operate.

[0006] This application provides a method for automatically calibrating small-angle scattering (SAS) layout parameters. The method includes: obtaining the estimated center coordinates of a standard sample's two-dimensional SOS spectrum by utilizing the central symmetry of the two-dimensional scattering intensity distribution; calibrating the estimated center coordinates by optimizing the deviation value of the one-dimensional scattering intensity distribution along the symmetry direction to obtain calibrated center coordinates; obtaining a ring integral one-dimensional scattering curve based on the calibrated center coordinates; obtaining the abscissa corresponding to the vertex of the first scattering peak in the ring integral one-dimensional scattering curve; and calculating the distance from the standard sample to the detector based on the abscissa corresponding to the vertex of the first scattering peak in the ring integral one-dimensional scattering curve and the magnitude of the scattering vector of the first scattering peak of the standard sample.

[0007] The method for automatically calibrating small-angle scattering layout parameters provided in this application can perform fully automated data analysis and provide layout parameters such as the center of the two-dimensional scattering spectrum and the distance from the sample to the detector. It is applicable to various small-angle scattering spectrometers based on circular apertures and two-dimensional position-sensitive detectors, such as small-angle neutron scattering, small-angle X-ray scattering, and ultra-small-angle X-ray scattering spectrometers.

[0008] The method for automatically calibrating small-angle scattering layout parameters provided in this application has at least the following advantages:

[0009] 1. Simple and convenient operation. Relying on the fully automatic processing flow of the algorithm program, it only requires loading the two-dimensional small-angle scattering spectrum file to automatically obtain layout parameters such as the center of the two-dimensional scattering spectrum and the distance from the sample to the detector, thus freeing up manpower.

[0010] 2. User-friendly and easy to operate. No longer requiring extensive data processing experience, researchers can process standard sample data independently.

[0011] 3. High accuracy and stability. The analysis process, relying on automated algorithms, eliminates interference from human factors and avoids the introduction of accidental human errors, resulting in high repeatability, reliability, and stability.

[0012] 4. Fast and highly efficient analysis. The data analysis methodology eliminates manual processing steps, with seamless integration of the analysis process. Furthermore, the algorithm has been optimized to improve analysis efficiency while ensuring accuracy, saving time on standard sample experimental data processing.

[0013] 5. Enables online real-time analysis. After acquiring calibration experimental data, a fully automated analysis method that requires no human intervention facilitates online real-time analysis and can be embedded into the design architecture of online real-time experimental systems. Attached Figure Description

[0014] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 A flowchart of the method for automatically calibrating small-angle scattering layout parameters provided in this application.

[0016] Figure 2 This is a one-dimensional data diagram of small-angle neutron scattering of silver behenate powder obtained in Example 1 of this application.

[0017] Figure 3 This is a one-dimensional small-angle X-ray scattering (SAXS) data diagram of silver behenate powder obtained in Example 2 of this application.

[0018] Figure 4 This is a one-dimensional data diagram of ultra-small angle X-ray scattering obtained in Embodiment 3 of this application. Detailed Implementation

[0019] This application provides a method for automatically calibrating small-angle scattering (SAS) layout parameters. The method includes: obtaining the estimated center coordinates of a standard sample's two-dimensional SOS spectrum by utilizing the central symmetry of the two-dimensional scattering intensity distribution; calibrating the estimated center coordinates by optimizing the deviation value of the one-dimensional scattering intensity distribution along the symmetry direction to obtain calibrated center coordinates; obtaining a ring integral one-dimensional scattering curve based on the calibrated center coordinates; obtaining the abscissa corresponding to the vertex of the first scattering peak in the ring integral one-dimensional scattering curve; and calculating the distance from the standard sample to the detector based on the abscissa corresponding to the vertex of the first scattering peak in the ring integral one-dimensional scattering curve and the magnitude of the scattering vector of the first scattering peak of the standard sample.

[0020] The method for automatically calibrating small-angle scattering layout parameters provided in this application enables fully automated processing of standard sample scattering data used in small-angle neutron scattering / small-angle X-ray scattering / ultra-small-angle X-ray scattering. It can obtain spectrometer layout parameters that are indispensable for subsequent processing of experimental sample data, such as the coordinates of the two-dimensional scattering spectrum center and the distance from the sample to the detector. It can be used to further design automated preprocessing programs for small-angle scattering data. It avoids human error introduced by manual processing and has the advantages of being fast, simple, efficient, accurate, stable, and easy to operate.

[0021] The method for automatically calibrating small-angle scattering layout parameters provided in this application can perform fully automated data analysis and is applicable to various small-angle scattering spectrometers based on circular apertures and two-dimensional position-sensitive detectors, such as small-angle neutron scattering, small-angle X-ray scattering, and ultra-small-angle X-ray scattering spectrometers.

[0022] Figure 1 For a flowchart of the method for automatically calibrating small-angle scattering layout parameters provided in this application, please refer to [link / reference]. Figure 1 The method for automatically calibrating small-angle scattering layout parameters provided in this application includes the following steps:

[0023] S110: Obtain the two-dimensional small-angle scattering spectrum of the standard sample.

[0024] In this application, the two-dimensional small-angle scattering spectrum can be: a two-dimensional small-angle neutron scattering spectrum, a two-dimensional small-angle X-ray scattering spectrum, or a two-dimensional ultra-small-angle X-ray scattering spectrum.

[0025] In this application, the method for obtaining the two-dimensional small-angle scattering spectrum of a standard sample includes:

[0026] S111, Standard sample preparation.

[0027] In some optional embodiments of this application, the standard sample is often a silver behenate powder sample or a tendon sample.

[0028] The method for automatically calibrating small-angle scattering layout parameters provided in this application is particularly suitable for two commonly used standard samples for small-angle scattering: silver behenate powder and ox tendon. It has been specifically designed to fully consider the scattering spectrum characteristics of these two commonly used standard samples, has high discriminative power, and ensures accuracy.

[0029] S112, Standard sample measurement.

[0030] The standard sample is placed on a small-angle scattering sample stage and the light path passes through the standard sample. The standard sample is measured at a specific wavelength to obtain a two-dimensional scattering data file of the standard sample.

[0031] As an example, small-angle X-ray scattering and ultra-small-angle X-ray scattering spectrometers are based on one of synchrotron radiation sources and laboratory X-ray sources; small-angle neutron scattering spectrometers are based on one of reactor neutron sources, pulsed reactor neutron sources, spallation neutron sources and accelerator neutron sources.

[0032] S113, Backside measurement.

[0033] Measure the background signal and obtain a two-dimensional background data file.

[0034] S114, Data Correction.

[0035] The software loads the two-dimensional scattering data file and two-dimensional background data file of the standard sample, reads the scattering data as a two-dimensional matrix, performs background subtraction on the experimental data of the standard sample, and obtains the corrected two-dimensional small-angle scattering spectrum of the standard sample.

[0036] In this application, relying on the fully automated processing flow of the algorithm program, only the original measurement data files of the standard sample scattering and background need to be loaded, and the layout parameters such as the center of the two-dimensional scattering spectrum and the distance from the sample to the detector can be automatically obtained in subsequent steps, freeing up manpower.

[0037] Furthermore, in some optional embodiments of this application, if necessary, the scattering spectrum may also be corrected for detector efficiency and anomaly masking may be performed during the data correction step.

[0038] S120 utilizes the central symmetry of the two-dimensional scattering intensity distribution to obtain the estimated center coordinates of the two-dimensional small-angle scattering spectrum of the standard sample.

[0039] In this application, the estimated center coordinates of the two-dimensional small-angle scattering spectrum of the obtained standard sample are pixel coordinates. Utilizing the principle that the two-dimensional small-angle scattering spectrum has central symmetry, the center adaptive estimation method is used to estimate the center pixel coordinates of the two-dimensional small-angle scattering spectrum of the standard sample.

[0040] Specifically, the estimated center coordinates (x, y) are obtained according to formulas (1) and (2). c0 ,z c0 Formula (1) is as follows:

[0041] x c0 =[ <x> 0.045×max(I)<I<0.055×max(I) ]

[0042] Formula (2) is as follows:

[0043] z c0 =[ <z> 0.045×max(I)<I<0.055×max(I) ]

[0044] In the formula:

[0045] x c0 The estimated value of the horizontal pixel coordinates of the center of the two-dimensional small-angle scattering spectrum.

[0046] z c0 The estimated value of the vertical pixel coordinates of the center of the two-dimensional small-angle scattering spectrum.

[0047] <x> C It is the average value of the horizontal pixel coordinates of each pixel point on the two-dimensional small-angle scattering spectrum map that satisfies the limiting condition C (the limiting condition C is 0.045×max(I) < I < 0.055×max(I)).

[0048] <z> C It is the average value of the vertical pixel coordinates of each pixel point on the two-dimensional small-angle scattering spectrum that satisfies the limiting condition C (the limiting condition C is 0.045×max(I) < I < 0.055×max(I)).

[0049] I is the scattering intensity, the neutron count or the X-ray count of each pixel point on the two-dimensional small-angle scattering spectrum.

[0050] max(I) is the maximum value of I.

[0051] […] means rounding.

[0052] In the above manner, the estimated center coordinates can be quickly obtained through the programmed formulas (1) and (2).

[0053] S130, calibrate the estimated center coordinates by optimizing the deviation value of the one-dimensional scattering intensity distribution in the symmetric direction to obtain the calibrated center coordinates.

[0054] In this application, the calibrated center coordinates are pixel coordinates, and the center pixel coordinates of the two-dimensional small-angle scattering spectrum are calibrated using the center automatic calibration algorithm.

[0055] Specifically, the steps for calibrating the estimated center coordinates include:

[0056] S131, with x c0 -n as the minimum value, x c0 +n as the maximum value, and m as the interval, generate an array {x ca}; with z c0 -n as the minimum value, z c0 +n as the maximum value, and m as the interval, generate an array {z ca}; where, ±n is the scanning range centered on the estimated center coordinates (x c0 , z c0 ), and m is the accuracy of the calibrated center coordinates (x c , z c ).

[0057] As an example, n can take the value of 10, and m can take the value of 0.5; it should be noted that the values of n and m can be adjusted according to the actual situation.

[0058] S132, with (x i , z c0 ) as the integration center, integrate the -x direction (horizontally to the left) R° sector to obtain a one-dimensional curve I -x (r|(x i , z c0 )), and integrate the +x direction (horizontally to the right) R° sector to obtain a one-dimensional curve I +x (r|(x i ,z c0 )); with (x c0 ,z i Using ) as the integration center, integrate over a sector R° in the -z direction (vertically downward) to obtain a one-dimensional curve I. -z (r|(x c0 ,z i Integrating over the +z direction (vertically upward) R° sector yields a one-dimensional curve I. +z (r|(x c0 ,z i )); where x i ∈{x ca }, z i ∈{z ca }, R° is the degree range of the sector, and r is the pixel distance between the pixel point of the two-dimensional small-angle scattering spectrum and the integration center.

[0059] For example, R° can be 30°; it should be noted that the value of R° can be adjusted according to the actual situation.

[0060] The sector is integrated according to formula (9); formula (9) is as follows:

[0061]

[0062] In the formula:

[0063] 'a' represents the pixel coordinates of the integration center in the horizontal direction on the two-dimensional small-angle scattering spectrum during integration.

[0064] b represents the pixel coordinates of the integration center in the vertical direction on the two-dimensional small-angle scattering spectrum during integration.

[0065] r is the pixel distance between the pixel point of the two-dimensional small-angle scattering spectrum and the center of integration.

[0066] x represents the horizontal pixel coordinates of each pixel on the two-dimensional small-angle scattering spectrum.

[0067] z represents the vertical pixel coordinates of each pixel in the two-dimensional small-angle scattering spectrum.

[0068] Indicates azimuth. Let be the angle between the line connecting each pixel in the two-dimensional small-angle scattering spectrum to the integration center (a, b) and the +z direction, expressed in rad, with positive values ​​in the counterclockwise direction. and These are the starting and ending azimuth angles of the sector, respectively.

[0069] As an example, the interval of the sequence is taken as 1.

[0070] S133, remove I -x (r|(x i ,z c0 )), I +x (r|(x i ,z c0 )), I -z (r|(x c0 ,z i )) and I +z (r|(x c0 ,z i Non-numerical points in the curve are extracted, and the edges of the one-dimensional curve are automatically detected through differential calculation, and the data of the beam blocker region is subtracted; I is truncated. -x (r|(x i ,z c0 )) and I +x (r|(x i ,z c0 I within the overlapping range of r values -x (r|(x i ,z c0 )) for I -x (r|(x i ,z c0 ))′ sequence, in I -x (r|(x i ,z c0 At the value of r of ))′ for I +x (r|(x i ,z c0 Linear interpolation is performed to obtain I. +x (r|(x i ,z c0 ))′ sequence; extract I -z (r|(x c0 ,z i )) and I +z (r|(x c0 ,z i I within the overlapping range of r values -z (r|(x c0 ,z i )) for I -z (r|(x c0 ,z i ))′ sequence, in I -z (r|(x c0 ,z i At the value of r of ))′ for I +z (r|(x c0 ,z i Linear interpolation is performed to obtain I. +z (r|(x c0 ,z i ))'sequence.

[0071] S134, I is obtained according to formula (3) and formula (4). -x (r|(x i ,z c0 ))′ and I +x (r|(x i ,z c0 The degree of deviation of ))′

[0072] Formula (3) is as follows:

[0073]

[0074] Formula (4) is as follows:

[0075]

[0076] In the formula:

[0077] To set the integration center of the two-dimensional small-angle scattering spectrum as (x i ,z c0 ) time I -x (r|(x i ,z c0 ))′ and I +x (r|(x i ,z c0 The degree of deviation of ))′.

[0078] N is the total number of elements corresponding to the sequence.

[0079] j is the element number corresponding to the sequence, j = 1, 2, 3, ...

[0080] Obtained through step S134 Regarding x i The function.

[0081] S135, I is obtained according to formulas (5) and (6). -z (r|(x c0 ,z i ))′ and I +z (r|(x c0 ,z i The degree of deviation between ))′

[0082] Formula (5) is as follows:

[0083]

[0084] Formula (6) is as follows:

[0085]

[0086] In the formula:

[0087] To set the integration center of the two-dimensional small-angle scattering spectrum as (x c0 ,z i ) time I -z (r|(x c0 ,z i ))′ and I +z (r|(x c0 ,z i The degree of deviation of ))′.

[0088] N is the total number of elements corresponding to the sequence.

[0089] j is the element number corresponding to the sequence, j = 1, 2, 3, ...

[0090] Obtained through step S135 Regarding z i The function.

[0091] S136, according to formulas (7) and (8), for and The minimum value is used to obtain the calibration center coordinates (x). C ,z c ).

[0092] Formula (7) is as follows:

[0093]

[0094] Formula (8) is as follows:

[0095]

[0096] In the formula:

[0097] x c This is the calibration value for the horizontal pixel coordinates of the center of the two-dimensional small-angle scattering spectrum.

[0098] z c The vertical pixel coordinate calibration value is the center of the two-dimensional small-angle scattering spectrum.

[0099] min(...) means taking the minimum value.

[0100] The above method allows for the rapid acquisition of calibration center coordinates through programmed steps S131 to S136.

[0101] S140. Obtain the ring integral one-dimensional scattering curve based on the calibration center coordinates.

[0102] Based on formula (13) and the coordinates of the calibration center, the two-dimensional small-angle scattering spectrum of the standard sample is ring-integrated to obtain the ring-integrated one-dimensional scattering curve I(r) of the standard sample.

[0103] Formula (13) is as follows:

[0104]

[0105] In the formula:

[0106] x represents the horizontal pixel coordinates of each pixel on the two-dimensional small-angle scattering spectrum.

[0107] z represents the vertical pixel coordinates of each pixel in the two-dimensional small-angle scattering spectrum.

[0108] x C This is the calibration value for the horizontal pixel coordinates of the center of the two-dimensional small-angle scattering spectrum.

[0109] z C The vertical pixel coordinate calibration value is the center of the two-dimensional small-angle scattering spectrum.

[0110] r is the pixel distance between the pixel point of the two-dimensional small-angle scattering spectrum and the calibration center.

[0111] θ is the azimuth angle, in rad; I is the scattering intensity, neutron count or X-ray count of each pixel on the two-dimensional small-angle scattering spectrum.

[0112] S150, obtain the x-coordinate of the first scattering peak in the one-dimensional scattering curve of the ring integral.

[0113] In this application, based on the shape characteristics of the ring integral one-dimensional scattering curve, an automatic peak-finding algorithm is used to obtain the abscissa corresponding to the vertex of the first scattering peak in the ring integral one-dimensional scattering curve of the standard sample.

[0114] For small-angle neutron scattering, according to formula (10), the x-coordinate of the first scattering peak in the one-dimensional scattering curve of the ring integral is obtained.

[0115] Formula (10) is as follows:

[0116] r1=r| I(r)＝max(I(r))

[0117] In the formula:

[0118] r1 is the pixel x-coordinate corresponding to the vertex of the first scattering peak in the one-dimensional scattering curve of the ring integral.

[0119] I(r) is the one-dimensional scattering curve of the ring integral.

[0120] max(...) means taking the maximum value.

[0121] The above method can quickly and accurately obtain the abscissa corresponding to the first scattering peak in the ring integral one-dimensional scattering curve of a small-angle neutron scattering experiment, and is particularly suitable for standard samples commonly used in small-angle scattering, such as silver behenate powder.

[0122] For small-angle X-ray scattering or ultra-small-angle X-ray scattering, an intensity band scan is performed on the vertical axis of the ring integral one-dimensional scattering curve using an iterative algorithm to obtain the horizontal axis corresponding to the vertex of the first scattering peak in the ring integral one-dimensional scattering curve.

[0123] Specifically, for small-angle X-ray scattering or ultra-small-angle X-ray scattering, methods for obtaining the x-coordinate corresponding to the vertex of the first scattering peak in the one-dimensional scattering curve of the ring integral include:

[0124] (1) The edge of the ring integral one-dimensional scattering curve is automatically detected by differential calculation, and the data of the beam blocker region is deducted.

[0125] (2) Based on the shape characteristics of the one-dimensional scattering curve of the ring integral of the standard sample, let the initial value of the iteration identifier I1 be as shown in formula (11), which is as follows:

[0126] I1 = max(I(r))

[0127] In the formula:

[0128] I(r) is the one-dimensional scattering curve of the ring integral.

[0129] max(...) means taking the maximum value.

[0130] The iterative assignment is shown in formula (12), which is as follows:

[0131]

[0132] The iteration process ends when both conditions A and B are met simultaneously.

[0133] Condition A is: the number of discrete elements of I(r) that satisfy the condition 0.9I1<I(r)<1.1I1 is ≥2.

[0134] Condition B is: the maximum value of the difference between the index of the sequence corresponding to I(r) that satisfies the condition 0.9I1<I(r)<1.1I1 and the index of the sequence (i.e., the position of the corresponding r value in the discrete r sequence from smallest to largest) is >2.

[0135] Condition A is shown in formula (15), and condition B is shown in formula (16).

[0136] Formula (15) is as follows:

[0137] numel(I(r|0.9I1<I(r)<1.1I1)≥2

[0138] Formula (16) is as follows:

[0139] max(diff(index(r|0.9I1<I(r)<1.1I1)))>2

[0140] In the formula:

[0141] numel(...) represents the number of discrete elements.

[0142] diff(...) represents difference calculation.

[0143] index(r|0.9I1<I(r)<1.1I1) represents the sequence of numbers corresponding to I(r) that satisfy the condition 0.9I1<I(r)<1.1I1.

[0144] max(...) means taking the maximum value.

[0145] The above conditions being met indicates that the intensity of the first scattering peak of the standard sample is between 0.9I1 and 1.1I1.

[0146] (3) Let the element to the right of the first difference > 2 in the index be n1; if there is only 1 difference > 2 in the index, let the last element of the index be n2; if there are ≥ 2 differences > 2 in the index, let the element to the left of the second difference > 2 in the index be n2.

[0147] Therefore, the n1 to n2 points of I(r) can be considered to be located in the region near the vertex of the first scattering peak of the standard sample.

[0148] (4) Take the point with the largest I value among the n1 to n2 points of I(r) as the x-coordinate r1 of the pixel corresponding to the vertex of the first scattering peak in the one-dimensional scattering curve of the standard sample ring integral.

[0149] As shown in formula (17), formula (17) is as follows:

[0150]

[0151] In the formula, max(...) represents taking the maximum value.

[0152] The above method can quickly and accurately obtain the abscissa corresponding to the first scattering peak in the ring integral one-dimensional scattering curve of small-angle X-ray scattering or ultra-small-angle X-ray scattering experiments. It is particularly suitable for silver behenate powder and tendon, two commonly used standard samples for small-angle scattering.

[0153] S160. Based on the x-coordinate of the first scattering peak in the one-dimensional scattering curve of the ring integral and the magnitude of the scattering vector of the first scattering peak of the standard sample, calculate the distance from the standard sample to the detector.

[0154] Based on the known scattering vector magnitude of the first scattering peak of the standard sample, and combined with formula (14), the distance SDD from the standard sample to the detector is obtained.

[0155] Formula (14) is as follows:

[0156]

[0157] In the formula:

[0158] r1 is the pixel x-coordinate corresponding to the vertex of the first scattering peak in the one-dimensional scattering curve of the ring integral.

[0159] p represents the pixel width of the detector.

[0160] λ is the wavelength of a neutron or an X-ray.

[0161] q1 is the magnitude of the scattering vector of the first scattering peak of the standard sample.

[0162] If the standard sample is silver behenate powder, then the scattering vector magnitude of the first small-angle scattering peak of the standard sample is q1 = 1.076 nm. -1 If the standard sample is made of gluten, then the magnitude of the scattering vector of the first small-angle scattering peak of the standard sample is q1 = 0.098 nm. -1 .

[0163] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0164] Example 1

[0165] This embodiment provides a method for automatically calibrating small-angle scattering (SAS) configuration parameters. The standard sample is silver behenate powder, and the SES is the Suanni small-angle scattering spectrometer from the Mianyang Research Reactor in China. The specific steps include the following:

[0166] (1) Preparation of standard samples

[0167] Prepare standard samples of silver behenate powder.

[0168] (2) Standard sample measurement

[0169] The silver behenate powder sample was placed on a small-angle neutron scattering sample stage and the light path was made to pass through the sample. The silver behenate powder sample was measured under the condition of neutron wavelength λ = 0.53 nm, and the two-dimensional scattering sample data file was saved.

[0170] (3) Back-bottom measurement

[0171] Measure the background signal and save the two-dimensional scattering background data file.

[0172] (4) Data correction

[0173] The two-dimensional scattering sample data file and the two-dimensional scattering background data file of silver behenate powder were loaded into MATLAB software. The scattering data was read as a two-dimensional matrix. The background was subtracted from the experimental data of silver behenate powder to obtain the corrected two-dimensional small-angle neutron scattering spectrum of silver behenate powder.

[0174] (5) Central Estimation

[0175] The estimated center coordinates (x) are obtained using formulas (1) and (2). c0 ,z c0 Formula (1) is as follows:

[0176] x c0 =[ <x> 0.045×max(I)<I<0.055×max(I) ]

[0177] Formula (2) is as follows:

[0178] z c0 =[ <z> 0.045×max(I)<I<0.055×max(I) ]

[0179] In the formula:

[0180] z c0 The estimated value of the horizontal pixel coordinates of the center of the two-dimensional small-angle scattering spectrum.

[0181] z c0 The estimated value of the vertical pixel coordinates of the center of the two-dimensional small-angle scattering spectrum.

[0182] <x> C It is the average value of the horizontal pixel coordinates of each pixel point on the two-dimensional small-angle scattering spectrum that satisfies the limiting condition C (the limiting condition C is 0.045×max(I) < I < 0.055×max(I)).

[0183] <z> C It is the average of the vertical pixel coordinates of each pixel point on the two-dimensional small-angle scattering spectrum that satisfies the limiting condition C (the limiting condition C is 0.045×max(I) < I < 0.055×max(I)).

[0184] I is the scattering intensity, the neutron count or the X-ray count of each pixel point on the two-dimensional small-angle scattering spectrum.

[0185] max(I) is the maximum value of I.

[0186] […] means rounding down.

[0187] (6) Center calibration

[0188] With x c0 -10 as the minimum value, x c0 +10 as the maximum value, and 0.5 as the interval, generate an array {x ca}; with z c0 -10 as the minimum value, z c0 +10 as the maximum value, and 0.5 as the interval, generate an array {z ca}; where, ±10 is the scanning range centered on the estimated center coordinates (x c0 , z c0 ), and 0.5 is the accuracy for calibrating the center coordinates (x c , z c ).

[0189] With (x[[ID=4⃣0]] i , z c0 ) as the integration center, integrate the -x direction (horizontally to the left) 30° sector to obtain a one-dimensional curve I -x (r|(x i , z c0 )), integrate the +x direction (horizontally to the right) 30° sector to obtain a one-dimensional curve I +x (r|(x i , z c0 )); with (x c0 , z i ) as the integration center, integrate the -z direction (vertically downwards) 30° sector to obtain a one-dimensional curve I -z (r|(x c0 , z i )), integrate the +z direction (vertically upwards) 30° sector to obtain a one-dimensional curve I +z (r|(x c0 , z i )); where, x i ∈ {x ca}, z i ∈ {z ca}, where 30° is the degree range of the sector, and r is the pixel distance between the pixel point of the two-dimensional small-angle scattering spectrum and the integration center.

[0190] The sector is integrated according to formula (9); formula (9) is as follows:

[0191]

[0192] In the formula:

[0193] 'a' represents the pixel coordinates of the integration center in the horizontal direction on the two-dimensional small-angle scattering spectrum during integration.

[0194] b represents the pixel coordinates of the integration center in the vertical direction on the two-dimensional small-angle scattering spectrum during integration.

[0195] r is the pixel distance between the pixel point of the two-dimensional small-angle scattering spectrum and the center of integration.

[0196] x represents the horizontal pixel coordinates of each pixel on the two-dimensional small-angle scattering spectrum.

[0197] z represents the vertical pixel coordinates of each pixel in the two-dimensional small-angle scattering spectrum.

[0198] Indicates azimuth. Let be the angle between the line connecting each pixel in the two-dimensional small-angle scattering spectrum to the integration center (a, b) and the +z direction, expressed in rad, with positive values ​​in the counterclockwise direction. and These are the starting and ending azimuth angles of the sector, respectively.

[0199] The interval of the sequence is 1.

[0200] Remove I -x (r|(x i ,z c0 )), I +x (r|(x i ,z c0 )), I -z (r|(x c0 ,z i )) and I +z (r|(x c0 ,z i Non-numerical points in the curve are extracted, and the edges of the one-dimensional curve are automatically detected through differential calculation, and the data of the beam blocker region is subtracted; I is truncated. -x (r|(x i ,z c0 )) and I +x (r|(x i ,z c0 I within the overlapping range of r values -x (r|(x i ,z c0 )) for I -x (r|(x i ,z c0 ))′ sequence, in I -x (r|(x i ,z c0 At the value of r of ))′ for I +x (r|(x i ,z c0 Linear interpolation is performed to obtain I. +x (r|(x i ,z c0 ))′ sequence; extract I -z (r|(x c0 ,z i )) and I +z (r|(x c0 ,z i I within the overlapping range of r values -z (r|(x c0 ,z i )) for I -z (r|(x c0 ,z i ))′ sequence, in I -z (r|(x c0 ,z i At the value of r of ))′ for I +z (r|(x c0 ,z i Linear interpolation is performed to obtain I. +z (r|(x c0 ,z i ))'sequence.

[0201] According to formulas (3) and (4), I is obtained -x (r|(x i ,z c0 ))′ and I +x (r|(x i ,z c0 The degree of deviation of ))′

[0202] Formula (3) is as follows:

[0203]

[0204] Formula (4) is as follows:

[0205]

[0206] In the formula:

[0207] To set the integration center of the two-dimensional small-angle scattering spectrum as (x i ,z c0 ) time I -x (r|(x i ,z c0 ))′ and I +x (r|(x i ,z c0 The degree of deviation of ))′.

[0208] N is the total number of elements corresponding to the sequence.

[0209] j is the element number corresponding to the sequence, j = 1, 2, 3, ...

[0210] According to formulas (5) and (6), I is obtained -z (r|(x c0 ,z i ))′ and I +z (r|(x c0 ,z i The degree of deviation between ))′

[0211] Formula (5) is as follows:

[0212]

[0213] Formula (6) is as follows:

[0214]

[0215] In the formula:

[0216] To set the integration center of the two-dimensional small-angle scattering spectrum as (x c0 ,z i ) time I -z (r|(x c0 ,z i ))′ and I +z (r|(x c0 ,z i The degree of deviation of ))′.

[0217] N is the total number of elements corresponding to the sequence.

[0218] j is the element number corresponding to the sequence, j = 1, 2, 3, ...

[0219] According to formulas (7) and (8), for and The minimum value is used to obtain the calibration center coordinates (x). c ,z c ).

[0220] Formula (7) is as follows:

[0221]

[0222] Formula (8) is as follows:

[0223]

[0224] In the formula:

[0225] x c This is the calibration value for the horizontal pixel coordinates of the center of the two-dimensional small-angle scattering spectrum.

[0226] z c The vertical pixel coordinate calibration value is the center of the two-dimensional small-angle scattering spectrum.

[0227] min(...) means taking the minimum value.

[0228] (7) One-dimensional transformation

[0229] Based on formula (13) and the coordinates of the calibration center, the two-dimensional small-angle scattering spectrum of the standard sample is ring-integrated to obtain the ring-integrated one-dimensional scattering curve I(r) of the standard sample.

[0230] Formula (13) is as follows:

[0231]

[0232] In the formula:

[0233] x represents the horizontal pixel coordinates of each pixel on the two-dimensional small-angle scattering spectrum.

[0234] z represents the vertical pixel coordinates of each pixel in the two-dimensional small-angle scattering spectrum.

[0235] x c This is the calibration value for the horizontal pixel coordinates of the center of the two-dimensional small-angle scattering spectrum.

[0236] z c The vertical pixel coordinate calibration value is the center of the two-dimensional small-angle scattering spectrum.

[0237] r is the pixel distance between the pixel point of the two-dimensional small-angle scattering spectrum and the calibration center.

[0238] θ is the azimuth angle, in rad; I is the scattering intensity, neutron count or X-ray count of each pixel on the two-dimensional small-angle scattering spectrum.

[0239] (8) Automatic peak finding

[0240] According to formula (10), obtain the x-coordinate corresponding to the vertex of the first scattering peak in the one-dimensional scattering curve of the ring integral.

[0241] Formula (10) is as follows:

[0242] r1=r| I(r)＝max(I(r))

[0243] In the formula:

[0244] r1 is the pixel x-coordinate corresponding to the vertex of the first scattering peak in the one-dimensional scattering curve of the ring integral.

[0245] I(r) is the one-dimensional scattering curve of the ring integral.

[0246] max(...) means taking the maximum value.

[0247] (9) SDD calculation

[0248] Based on the known scattering vector magnitude q1 = 1.076 nm of the first small-angle scattering peak of the silver behenate powder sample. -1 Combined with formula (14), the distance SDD from the standard sample to the detector is obtained.

[0249] Formula (14) is as follows:

[0250]

[0251] In the formula:

[0252] r1 is the pixel x-coordinate corresponding to the vertex of the first scattering peak in the one-dimensional scattering curve of the ring integral.

[0253] p represents the pixel width of the detector.

[0254] λ is the wavelength of a neutron or an X-ray.

[0255] q1 is the magnitude of the scattering vector of the first scattering peak of the standard sample.

[0256] The one-dimensional small-angle neutron scattering data of silver behenate powder obtained in this embodiment are as follows: Figure 2 As shown.

[0257] Example 2

[0258] This embodiment provides a method for automatically calibrating small-angle scattering (SAS) layout parameters. The standard sample is silver behenate powder, and the SAS small-angle X-ray scattering spectrometer is the BL19U2 beamline SAS small-angle X-ray scattering spectrometer of the Shanghai Synchrotron Radiation Facility.

[0259] The only difference between this embodiment and embodiment 1 is the difference in the specific operation steps: step (2) and step (8).

[0260] Step (2): Standard sample measurement

[0261] The silver behenate powder sample was placed on a small-angle X-ray scattering stage and the light path was made to pass through the sample. The silver behenate powder sample was measured under the condition of X-ray wavelength λ = 0.124 nm, and the two-dimensional scattering sample data file was saved.

[0262] Step (8): Automatic peak finding

[0263] The edge of the one-dimensional scattering curve of the ring integral is automatically detected by differential calculation, and the data of the beam blocker region is deducted.

[0264] Based on the shape characteristics of the one-dimensional scattering curve of the ring integral of the standard sample, let the initial value of the iteration identifier I1 be as shown in formula (11), which is as follows:

[0265] I1 = max(I(r))

[0266] In the formula:

[0267] I(r) is the one-dimensional scattering curve of the ring integral.

[0268] max(...) means taking the maximum value.

[0269] The iterative assignment is shown in formula (12), which is as follows:

[0270]

[0271] The iteration process ends when both conditions A and B are met simultaneously.

[0272] Condition A is: the number of discrete elements of I(r) that satisfy the condition 0.9I1<I(r)<1.1I1 is ≥2.

[0273] Condition B is: the maximum value of the difference between the index of the sequence corresponding to I(r) that satisfies the condition 0.9I1<I(r)<1.1I1 and the index of the sequence (i.e., the position of the corresponding r value in the discrete r sequence from smallest to largest) is >2.

[0274] Condition A is shown in formula (15), and condition B is shown in formula (16).

[0275] Formula (15) is as follows:

[0276] numel(I(r|0.9I1<I(r)<1.1I1)≥2

[0277] Formula (16) is as follows:

[0278] max(diff(index(r|0.9I1<I(r)<1.1I1)))>2

[0279] In the formula:

[0280] numel(...) represents the number of discrete elements.

[0281] diff(...) represents difference calculation.

[0282] index(r|0.9I1<I(r)<1.1I1) represents the sequence of numbers corresponding to I(r) that satisfy the condition 0.9I1<I(r)<1.1I1.

[0283] max(...) means taking the maximum value.

[0284] Let n1 be the element to the right of the first difference > 2 in the index; if there is only one difference > 2 in the index, let n2 be the last element of the index; if there are ≥ 2 differences > 2 in the index, let n2 be the element to the left of the second difference > 2 in the index.

[0285] The r value corresponding to the point with the largest I value among the n1 to n2 points of I(r) is the pixel x-coordinate r1 corresponding to the vertex of the first scattering peak in the one-dimensional scattering curve of the standard sample ring integral.

[0286] As shown in formula (17), formula (17) is as follows:

[0287]

[0288] In the formula, max(...) represents taking the maximum value.

[0289] The one-dimensional small-angle X-ray scattering data of silver behenate powder obtained in this embodiment are as follows: Figure 3 As shown.

[0290] Example 3

[0291] This embodiment provides a method for automatically calibrating small-angle scattering layout parameters. The standard sample is selected as Niujin, and the ultra-small-angle X-ray scattering spectrometer is the BL10U1 beamline ultra-small-angle X-ray scattering spectrometer of the Shanghai Synchrotron Radiation Facility.

[0292] The only difference between this embodiment and embodiment 1 is the difference in the specific operation steps: steps (2), (8) and (9).

[0293] Step (2): Standard sample measurement

[0294] The tendon sample was placed on an ultra-small angle X-ray scattering sample stage and the light path was made to pass through the sample. The tendon sample was measured under the condition of X-ray wavelength λ = 0.124 nm, and the two-dimensional scattering sample data file was saved.

[0295] Step (8): Automatic peak finding

[0296] The edge of the one-dimensional scattering curve of the ring integral is automatically detected by differential calculation, and the data of the beam blocker region is deducted.

[0297] Based on the shape characteristics of the one-dimensional scattering curve of the ring integral of the standard sample, let the initial value of the iteration identifier I1 be as shown in formula (11), which is as follows:

[0298] I1 = max(I(r))

[0299] In the formula:

[0300] I(r) is the one-dimensional scattering curve of the ring integral.

[0301] max(...) means taking the maximum value.

[0302] The iterative assignment is shown in formula (12), which is as follows:

[0303]

[0304] The iteration process ends when both conditions A and B are met simultaneously.

[0305] Condition A is: the number of discrete elements of I(r) that satisfy the condition 0.9I1<I(r)<1.1I1 is ≥2.

[0306] Condition B is: the maximum value of the difference between the index of the sequence corresponding to I(r) that satisfies the condition 0.9I1<I(r)<1.1I1 and the index of the sequence (i.e., the position of the corresponding r value in the discrete r sequence from smallest to largest) is >2.

[0307] Condition A is shown in formula (15), and condition B is shown in formula (16).

[0308] Formula (15) is as follows:

[0309] numel(I(r|0.9I1<I(r)<1.1I1)≥2

[0310] Formula (16) is as follows:

[0311] max(diff(index(r|0.9I1<I(r)<1.1I1)))>2

[0312] In the formula:

[0313] numel(...) represents the number of discrete elements.

[0314] diff(...) represents difference calculation.

[0315] index(r|0.9I1<I(r)<1.1I1) represents the sequence of numbers corresponding to I(r) that satisfy the condition 0.9I1<I(r)<1.1I1.

[0316] max(...) means taking the maximum value.

[0317] Let n1 be the element to the right of the first difference > 2 in the index; if there is only one difference > 2 in the index, let n2 be the last element of the index; if there are ≥ 2 differences > 2 in the index, let n2 be the element to the left of the second difference > 2 in the index.

[0318] The r value corresponding to the point with the largest I value among the n1 to n2 points of I(r) is the pixel x-coordinate r1 corresponding to the vertex of the first scattering peak in the one-dimensional scattering curve of the standard sample ring integral.

[0319] As shown in formula (17), formula (17) is as follows:

[0320]

[0321] In the formula, max(...) represents taking the maximum value.

[0322] Step (9): SDD Calculation

[0323] Based on the known magnitude of the scattering vector of the first small-angle scattering peak of the beef tendon sample, q1 = 0.098 nm. -1 Combined with formula (14), the distance SDD from the standard sample to the detector is obtained.

[0324] Formula (14) is as follows:

[0325]

[0326] In the formula:

[0327] r1 is the pixel x-coordinate corresponding to the vertex of the first scattering peak in the one-dimensional scattering curve of the ring integral.

[0328] p represents the pixel width of the detector.

[0329] λ is the wavelength of a neutron or an X-ray.

[0330] q1 is the magnitude of the scattering vector of the first scattering peak of the standard sample.

[0331] The one-dimensional data of ultrasmall angle X-ray scattering obtained in this embodiment are as follows: Figure 4 As shown.

[0332] Comparative Example 1

[0333] This comparative example provides a method for obtaining small-angle scattering (SAS) configuration parameters. The standard sample is silver behenate powder, and the SAS spectrometer used is the Suanni small-angle neutron scattering spectrometer from the Mianyang Research Reactor in China. The specific steps include the following:

[0334] (1) Preparation of standard samples

[0335] Prepare standard samples of silver behenate powder.

[0336] (2) Standard sample measurement

[0337] The silver behenate powder sample was placed on a small-angle neutron scattering sample stage and the light path was made to pass through the sample. The silver behenate powder sample was measured under the condition of neutron wavelength λ = 0.53 nm, and the two-dimensional scattering sample data file was saved.

[0338] (3) Back-bottom measurement

[0339] Measure the background signal and save the two-dimensional scattering background data file.

[0340] (4) Data correction

[0341] The two-dimensional scattering sample data file and the two-dimensional scattering background data file of the silver behenate powder sample were loaded using BerSANS software. The scattering data was read as a two-dimensional matrix. The background was subtracted from the experimental data of the silver behenate powder sample to obtain the corrected two-dimensional small-angle neutron scattering spectrum of the silver behenate powder.

[0342] (5) Obtain the center coordinates of the two-dimensional map

[0343] In the BerSANS software, input the preset center coordinates of the spectrum. Draw a circle C1 with these coordinates as the center, and adjust the radius of circle C1 to make circle C1 approach the scattering ring C2 of the standard sample. If C1 and C2 can completely overlap, then the preset center coordinates of the spectrum are the obtained center coordinates of the two-dimensional spectrum. If adjusting the radius of C1 cannot make C1 and C2 completely overlap, re-enter new preset center coordinates of the spectrum and try again until C1 and C2 can completely overlap.

[0344] (6) One-dimensional transformation

[0345] The one-dimensional scattering curve of the standard sample was obtained by ring integration of the two-dimensional small-angle scattering spectrum of the silver behenate powder sample.

[0346] (7) Fitting and Peak Finding

[0347] The scattering peaks of the one-dimensional scattering curve of the silver behenate powder sample were fitted with a Gaussian function to obtain the pixel x-coordinates of the peak positions.

[0348] (8) SDD calculation

[0349] Based on the known scattering vector magnitude q1 = 1.076 nm of the first small-angle scattering peak of the silver behenate powder sample. -1 Combined with formula (14), the distance SDD from the standard sample to the detector is obtained.

[0350] Formula (14) is as follows:

[0351]

[0352] In the formula:

[0353] r1 is the pixel x-coordinate corresponding to the vertex of the first scattering peak in the one-dimensional scattering curve of the ring integral.

[0354] p represents the pixel width of the detector.

[0355] λ is the wavelength of a neutron or an X-ray.

[0356] q1 is the magnitude of the scattering vector of the first scattering peak of the standard sample.

[0357] Comparative Example 2

[0358] This comparative example provides a method for automatically calibrating small-angle scattering (SAS) layout parameters. The standard sample is silver behenate powder, and the SAS small-angle X-ray scattering spectrometer is the BL19U2 beamline SAS small-angle X-ray scattering spectrometer at the Shanghai Synchrotron Radiation Facility.

[0359] The only difference between this comparative example and Comparative Example 1 is the specific operation steps: steps (2), (4), (5), and (7).

[0360] Step (2): Standard sample measurement

[0361] The silver behenate powder sample was placed on a small-angle X-ray scattering stage and the light path was made to pass through the sample. The silver behenate powder sample was measured under the condition of X-ray wavelength λ = 0.124 nm, and the two-dimensional scattering sample data file was saved.

[0362] Step (4): Data Correction

[0363] The two-dimensional scattering sample data file and the two-dimensional scattering background data file of the silver behenate powder sample were loaded using FIT2D software. The scattering data was read as a two-dimensional matrix. The background was subtracted from the experimental data of the silver behenate powder sample to obtain the corrected two-dimensional small-angle X-ray scattering spectrum of the silver behenate powder.

[0364] Step (5): Obtain the center coordinates of the two-dimensional map.

[0365] In the FIT2D software, click to select a series of pixels that are distributed in a circle around the center of the map. The software will analyze and provide the coordinates of the center of the circle, which are the coordinates of the center of the two-dimensional map.

[0366] Step (7): Manual peak finding

[0367] Manually locate the scattering peaks of the one-dimensional scattering curve of the silver behenate powder sample and obtain the pixel x-coordinates of the peak positions.

[0368] Comparative Example 3

[0369] This comparative example provides a method for automatically calibrating small-angle scattering layout parameters. The standard sample is Niujin, and the ultra-small-angle X-ray scattering spectrometer is the BL10U1 beamline ultra-small-angle X-ray scattering spectrometer of the Shanghai Synchrotron Radiation Facility.

[0370] The only difference between this comparative example and Comparative Example 1 lies in the specific operational steps: steps (2), (4), (5), (6), (7), and (8).

[0371] Step (2): Standard sample measurement

[0372] The tendon sample was placed on an ultra-small angle X-ray scattering sample stage and the light path was made to pass through the sample. The tendon sample was measured under the condition of X-ray wavelength λ = 0.124 nm, and the two-dimensional scattering sample data file was saved.

[0373] Step (4): Data Correction

[0374] The two-dimensional scattering sample data file and the two-dimensional scattering background data file of the beef tendon sample were loaded using FIT2D software. The scattering data was read as a two-dimensional matrix. The background was subtracted from the experimental data of the silver behenate powder sample to obtain the corrected two-dimensional small-angle X-ray scattering spectrum of the silver behenate powder.

[0375] Step (5): Obtain the center coordinates of the two-dimensional map.

[0376] In the FIT2D software, click to select a series of pixels that are distributed in a circle around the center of the map. The software will analyze and provide the coordinates of the center of the circle, which are the coordinates of the center of the two-dimensional map.

[0377] Step (6): One-dimensional transformation

[0378] By performing a ring integral on the two-dimensional small-angle scattering spectrum of the beef tendon sample, a one-dimensional scattering curve of the standard sample is obtained.

[0379] Step (7): Manual peak finding

[0380] Manually locate the scattering peaks of the one-dimensional scattering curve of the silver behenate powder sample and obtain the pixel x-coordinates of the peak positions.

[0381] Step (8): SDD Calculation

[0382] Based on the known scattering vector magnitude q1 = 0.098 nm of the first small-angle scattering peak of the ox-tendon sample. -1 Combined with formula (14), the distance SDD from the standard sample to the detector is obtained.

[0383] Formula (14) is as follows:

[0384]

[0385] In the formula:

[0386] r1 is the pixel x-coordinate corresponding to the vertex of the first scattering peak in the one-dimensional scattering curve of the ring integral.

[0387] p represents the pixel width of the detector.

[0388] λ is the wavelength of a neutron or an X-ray.

[0389] q1 is the magnitude of the scattering vector of the first scattering peak of the standard sample.

[0390] The layout parameters obtained from Examples 1-3 and Comparative Examples 1-3 are shown in Table 1.

[0391] Table 1

[0392]

[0393]

[0394] Table 1 shows that, through the comparison of Example 1 with Comparative Example 1, Example 2 with Comparative Example 2, and Example 3 with Comparative Example 3, it can be seen that the center coordinates of the two-dimensional spectra obtained in Examples 1-3 are basically consistent with the center coordinates of the two-dimensional spectra obtained by the traditional manual operation method (i.e., Comparative Examples 1-3). The sample-to-detector distances in Examples 1-3 are also basically consistent with the sample-to-detector distances obtained by the traditional manual operation method (i.e., Comparative Examples 1-3). This indicates that the layout parameters obtained by the automatic calibration method for small-angle scattering layout parameters provided in this application are comparable to those obtained by the traditional manual operation method. Since the automatic calibration method for small-angle scattering layout parameters provided in this application is a fully automatic data analysis, it has the advantages of being fast, efficient, highly accurate, and easy to operate compared to the traditional manual operation method.

[0395] In summary, the method for automatically calibrating small-angle scattering (SAS) layout parameters provided in this application achieves fully automated processing of standard sample scattering data used in small-angle neutron scattering, small-angle X-ray scattering, and ultra-small-angle X-ray scattering. It can obtain essential spectrometer layout parameters for subsequent processing of experimental sample data, such as the coordinates of the two-dimensional scattering spectrum center and the sample-to-detector distance, which can be used to further design automated preprocessing programs for SOS data. It avoids human error introduced by manual processing and has the advantages of being fast, simple, efficient, highly accurate, highly stable, and easy to operate. The method for automatically calibrating SOS layout parameters provided in this application can perform fully automated data analysis and is applicable to various types of SOS spectrometers based on circular apertures and two-dimensional position-sensitive detectors, including small-angle neutron scattering, small-angle X-ray scattering, and ultra-small-angle X-ray scattering spectrometers.

[0396] The embodiments described above are some, but not all, of the embodiments of this application. The detailed description of the embodiments in this application is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.< / z> < / x> < / z> < / x> < / z> < / x> < / z> < / x>

Claims

1. A method for automatically calibrating small-angle scattering layout parameters, characterized in that, include: By utilizing the central symmetry of the two-dimensional scattering intensity distribution, the estimated center coordinates of the two-dimensional small-angle scattering spectrum of the standard sample are obtained; The estimated center coordinates are calibrated by optimizing the deviation value of the one-dimensional scattering intensity distribution in the symmetrical direction; Based on the coordinates of the calibration center, obtain the ring integral one-dimensional scattering curve; Obtain the x-coordinate of the first scattering peak in the one-dimensional scattering curve of the ring integral; The distance from the standard sample to the detector is calculated based on the x-coordinate of the first scattering peak in the one-dimensional scattering curve of the ring integral and the magnitude of the scattering vector of the first scattering peak of the standard sample.

2. The method for automatically calibrating small-angle scattering layout parameters according to claim 1, characterized in that, The estimated center coordinates (x) are obtained according to formulas (1) and (2). c0 ,z c0 ); Formula (1) is as follows: x c0 ＝[ <x> 0.045×max(I)＜I＜0.055×max(I) ]< / x> Formula (2) is as follows: z c0 ＝[ <z> 0.045×max(I)<I<0.055×max(I) ]< / z> In the formula: x c0 The estimated value of the horizontal pixel coordinates of the center of the two-dimensional small-angle scattering spectrum; z c0 The estimated value of the vertical pixel coordinates of the center of the two-dimensional small-angle scattering spectrum; <x> C The average value of the horizontal pixel coordinates of each pixel point satisfying the constraint C on the two-dimensional small-angle scattering spectrum;< / x> <z> C The average value of the vertical pixel coordinates of each pixel point satisfying the constraint C on the two-dimensional small-angle scattering spectrum;< / z> I represents the scattering intensity, the neutron count or X-ray count of each pixel in the two-dimensional small-angle scattering spectrum; max(I) is the maximum value of I; [...] indicates rounding; Wherein, the limiting condition C is 0.045 × max(I). <I<0.055×max(I)。 3. The method for automatically calibrating small-angle scattering layout parameters according to claim 2, characterized in that, The steps for calibrating the estimated center coordinates include: With x c0 -n is the minimum value, x c0 +n represents the maximum value, m represents the interval, and the generated array is {x} ca };with z c0 -n is the minimum value, z c0 +n represents the maximum value, m represents the interval, and the generated array is {z} ca }; where ±n is the estimated center coordinates (x c0 ,z c0 The scanning range centered on ) is m, where m is the coordinate of the calibration center (x, y). c ,z c The accuracy of ) With (x i ,z c0 Using ) as the integration center, integrate over the R° sector in the -x direction to obtain the one-dimensional curve I. -x (r|(x i ,z c0 Integrating over the R° sector in the +x direction yields a one-dimensional curve I. +x (r|(x i ,z c0 )); with (x c0 ,z i Using ) as the integration center, integrate over the R° sector in the -z direction to obtain a one-dimensional curve I. -z (r|(x c0 ,z i Integrating over the R° sector in the +z direction yields a one-dimensional curve I. +z (r|(x c0 ,z i )); where x i ∈{x ca }, z i ∈{z ca }, R° is the degree range of the sector, and r is the pixel distance between the pixel point of the two-dimensional small angle scattering spectrum and the integration center; Remove I -x (r|(x i ,z c0 )), I +x (r|(x i ,z c0 )), I -z (r|(x c0 ,z i )) and I +z (r|(x c0 ,z i Non-numerical points in the curve are processed, and the edges of the one-dimensional curve are automatically detected through differential calculation, and the data of the beam blocker region is deducted; I is truncated. -x (r|(x i ,z c0 )) and I +x (r|(x i ,z c0 I within the overlapping range of r values -x (r|(x i ,z c0 )) for I -x (r|(x i ,z c0 ))′ sequence, in I -x (r|(x i ,z c0 At the r value of ))′ for I +x (r|(x i ,z c0 Linear interpolation is performed to obtain I. +x (r|(x i ,z c0 ))′ sequence; extract I -z (r|(x c0 ,z i )) and I +z (r|(x co ,z i I within the overlapping range of r values -z (r|(x c0 ,z i )) for I -z (r|(x c0 ,z i ))′ sequence, in I -z (r|(x c0 ,z i At the r value of ))′ for I +z (r|(x c0 ,z i Linear interpolation is performed to obtain I. +z (r|(x c0 ,z i ))'sequence; According to formulas (3) and (4), I is obtained -x (r|(x i ,z c0 ))′ and I +x (r|(x i ,z c0 The degree of deviation of ))′ Formula (3) is as follows: Formula (4) is as follows: In the formula: To set the integration center of the two-dimensional small-angle scattering spectrum as (x i ,z c0 ) time I -x (r|(x i ,z c0 ))′ and I +x (r|(x i ,z c0 The degree of deviation of ))′; N is the total number of elements corresponding to the sequence; j is the element number corresponding to the sequence; According to formulas (5) and (6), I is obtained -z (r|(x c0 ,z i ))′ and I +z (r|(x c0 ,z i The degree of deviation between ))′ Formula (5) is as follows: Formula (6) is as follows: In the formula: To set the integration center of the two-dimensional small-angle scattering spectrum as (x c0 ,z i ) time I -z (r|(x c0 ,z i ))′ and I +z (r|(x c0 ,z i The degree of deviation of ))′; N is the total number of elements corresponding to the sequence; j is the element number corresponding to the sequence; According to formulas (7) and (8), for and The minimum value is used to obtain the calibration center coordinates (x). c ,z c ); Formula (7) is as follows: Formula (8) is as follows: In the formula: x c The calibration value for the horizontal pixel coordinates of the center of the two-dimensional small-angle scattering spectrum; z c The vertical pixel coordinate calibration value of the center of the two-dimensional small-angle scattering spectrum; min(...) means taking the minimum value.

4. The method for automatically calibrating small-angle scattering layout parameters according to claim 3, characterized in that, The sector is integrated according to formula (9); Formula (9) is as follows: In the formula: a is the pixel coordinate of the integration center in the horizontal direction on the two-dimensional small-angle scattering spectrum when the integration is performed; b represents the pixel coordinates of the integration center in the vertical direction on the two-dimensional small-angle scattering spectrum when performing the integration. r is the pixel distance between the pixel point of the two-dimensional small-angle scattering spectrum and the integration center; x is the horizontal pixel coordinate of each pixel point on the two-dimensional small-angle scattering spectrum; z represents the vertical pixel coordinates of each pixel point on the two-dimensional small-angle scattering spectrum; Indicates azimuth. Let be the angle between the line connecting each pixel in the two-dimensional small-angle scattering spectrum to the integration center (a, b) and the +z direction, expressed in rad, with positive values ​​in the counterclockwise direction. and These are the starting azimuth and ending azimuth of the sector, respectively.

5. The method for automatically calibrating small-angle scattering layout parameters according to claim 1, characterized in that, For small-angle neutron scattering, according to formula (10), the abscissa corresponding to the vertex of the first scattering peak in the one-dimensional scattering curve of the ring integral is obtained; Formula (10) is as follows: r1＝r| I(r)＝max(I(r)) In the formula: r1 is the pixel x-coordinate corresponding to the vertex of the first scattering peak in the ring integral one-dimensional scattering curve; I(r) is the one-dimensional scattering curve of the ring integral; max(...) means taking the maximum value.

6. The method for automatically calibrating small-angle scattering layout parameters according to claim 1, characterized in that, For small-angle X-ray scattering or ultra-small-angle X-ray scattering, the method for obtaining the x-coordinate corresponding to the vertex of the first scattering peak in the ring integral one-dimensional scattering curve includes: The edges of the ring integral one-dimensional scattering curve are automatically detected by differential calculation, and the data of the beam blocker region is deducted. Based on the shape characteristics of the one-dimensional scattering curve of the ring integral, let the initial value of the iteration identifier I1 be as shown in formula (11), which is as follows: I1 = max(I(r)) In the formula: I(r) is the one-dimensional scattering curve of the ring integral; max(...) represents taking the maximum value; The iterative assignment is shown in formula (12), which is as follows: The iteration process continues until both conditions A and B are simultaneously satisfied, at which point the process exits. Condition A is: the number of discrete elements of I(r) that satisfy the condition 0.9I1<I(r)<1.1I1 is ≥2; Condition B is: the maximum value of the difference between the indexes corresponding to the numbering sequence I(r) that satisfies the condition 0.9I1 < I(r) < 1.1I1 is greater than 2; Let n1 be the element to the right of the first difference > 2 in the index; if there is only one difference > 2 in the index, let n2 be the last element of the index; if there are ≥ 2 differences > 2 in the index, let n2 be the element to the left of the second difference > 2 in the index. The r value corresponding to the point with the largest I value among the n1 to n2 points of I(r) is the pixel x-coordinate of the vertex of the first scattering peak in the one-dimensional scattering curve of the ring integral.

7. The method for automatically calibrating small-angle scattering layout parameters according to any one of claims 1 to 6, characterized in that, According to formula (13) and the calibration center coordinates, the two-dimensional small-angle scattering spectrum is ring-integrated to obtain the ring-integrated one-dimensional scattering curve I(r); Formula (13) is as follows: In the formula: x is the horizontal pixel coordinate of each pixel point on the two-dimensional small-angle scattering spectrum; z represents the vertical pixel coordinates of each pixel point on the two-dimensional small-angle scattering spectrum; x c The calibration value for the horizontal pixel coordinates of the center of the two-dimensional small-angle scattering spectrum; z c The vertical pixel coordinate calibration value of the center of the two-dimensional small-angle scattering spectrum; r is the pixel distance between the pixel point of the two-dimensional small-angle scattering spectrum and the calibration center; This is the azimuth angle, measured in rad. I represents the scattering intensity, the neutron count or X-ray count of each pixel on the two-dimensional small-angle scattering spectrum.

8. The method for automatically calibrating small-angle scattering layout parameters according to any one of claims 1 to 6, characterized in that, According to formula (14), the distance SDD from the standard sample to the detector is obtained; Formula (14) is as follows: In the formula: r1 is the pixel x-coordinate corresponding to the vertex of the first scattering peak in the ring integral one-dimensional scattering curve; p is the pixel width of the detector; λ is the wavelength of a neutron or an X-ray; q1 is the magnitude of the scattering vector of the first scattering peak of the standard sample.

9. The method for automatically calibrating small-angle scattering layout parameters according to any one of claims 1 to 6, characterized in that, The method for obtaining the two-dimensional small-angle scattering spectrum of the standard sample includes: The standard sample is placed on a small-angle scattering sample stage and the light path passes through the standard sample. The standard sample is measured at a specific wavelength to obtain a two-dimensional scattering data file of the standard sample. Measure the background signal and acquire a two-dimensional background data file; The software loads the two-dimensional scattering data file and the two-dimensional background data file of the standard sample, reads the scattering data as a two-dimensional matrix, and performs background subtraction processing on the experimental data of the standard sample to obtain the two-dimensional small-angle scattering spectrum of the standard sample.

10. The method for automatically calibrating small-angle scattering layout parameters according to any one of claims 1 to 6, characterized in that, The two-dimensional small-angle scattering spectrum is: a two-dimensional small-angle neutron scattering spectrum, a two-dimensional small-angle X-ray scattering spectrum, or a two-dimensional ultra-small-angle X-ray scattering spectrum.

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