Precise characterization and quantitative analysis method for blue calcite luminescence spectrum

Abstract

The invention belongs to the technical field of mineral spectral analysis, and provides an accurate characterization and quantitative analysis method for a blue calcite luminescent spectrum. According to the method, three excitation wavelengths of 265 nm, 335 nm and 405 nm are combined with a 80K-320K temperature gradient test and a time-resolved spectrum technology, manganese ions, rare earth ions and defect luminescence centers are accurately distinguished through a luminescence center recognition algorithm, accurate separation and quantification of luminescence peaks are realized by adopting a spectrum deconvolution technology, a quantitative analysis framework based on reference is established, the detection sensitivity is high, and the method is suitable for large-scale popularization and application. The quantification accuracy is gt; therefore, important technical support is provided for scientific research and application of the blue calcite.

Description

Technical Field

[0001] This invention belongs to the field of mineral spectral analysis technology, specifically relating to a method for precise characterization and quantitative analysis of the luminescence spectrum of blue calcite. Background Technology

[0002] Blue calcite is a calcium carbonate mineral containing unique color-causing centers. Its distinctive blue hue and luminescence properties give it significant value in mineralogical research and gemological applications. The color and luminescence of blue calcite primarily originate from various luminescent centers present in the crystal lattice, including manganese ions, rare earth elements, and lattice defects. The type, content, and distribution of these luminescent centers directly influence the optical properties and quality evaluation of blue calcite. Therefore, establishing an analytical method that can accurately characterize the luminescence properties of blue calcite and precisely quantify its luminescent center content is of great importance for scientific research, mineral identification, provenance tracing, and quality evaluation of blue calcite.

[0003] Traditional mineral luminescence analysis methods mainly include X-ray diffraction analysis, infrared spectroscopy analysis, and simple fluorescence spectroscopy analysis. CN112730310A discloses a rapid quantitative method for aragonite based on infrared spectroscopy, which measures... The method of quantifying aragonite content in carbonate minerals by analyzing the peak area of ​​CO bond characteristic peaks is based on infrared absorption spectroscopy, which only provides molecular vibrational information and cannot obtain electronic transition information of luminescent centers. Therefore, it is unsuitable for the precise characterization of the luminescence properties of blue calcite. Conventional fluorescence spectroscopy typically employs a single excitation wavelength and room temperature testing conditions. However, due to the presence of multiple luminescent centers in blue calcite, its emission spectrum often exhibits complex overlapping peak shapes. Using a single excitation wavelength makes it difficult to effectively distinguish the contributions of different luminescent centers, resulting in low sensitivity and poor accuracy in quantitative analysis. Furthermore, existing methods lack a systematic spectral analysis and quantitative analysis framework, making it impossible to establish a precise quantitative relationship between luminescence intensity and luminescent center content, thus hindering comprehensive characterization and high-precision quantitative analysis of the luminescence properties of blue calcite.

[0004] Therefore, there is an urgent need to develop a new analytical method that can comprehensively characterize the luminescence properties of blue calcite, accurately distinguish the contributions of different luminescence centers, and establish accurate quantitative relationships, so as to meet the urgent need for high-sensitivity and high-accuracy analytical technology in the scientific research and application fields of blue calcite. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the purpose of this invention is to provide a precise characterization and quantitative analysis method for the luminescence spectrum of blue calcite. This method employs a comprehensive analysis process combining multi-wavelength excitation and time-resolved spectral analysis, utilizing luminescence center identification algorithms and spectral deconvolution analysis techniques to achieve comprehensive characterization and high-precision quantitative analysis of the luminescence characteristics of blue calcite, thus solving the technical problems of low sensitivity and poor quantification in traditional luminescence analysis methods.

[0006] To achieve the above objectives, the technical solution provided by the present invention is as follows:

[0007] A precise characterization and quantitative analysis method for the luminescence spectrum of blue calcite, including the following steps:

[0008] Step 1, Sample preparation: Grind the blue calcite sample to a particle size of less than 200 mesh, dry it in an oven at 80℃ for 2 hours to remove adsorbed water, weigh 50mg of sample and compress it into a test sample sheet with a diameter of 10mm and a thickness of 1mm, and place it on the sample stage for testing.

[0009] Step 2, Multi-wavelength excitation spectrum acquisition: Three excitation wavelengths, namely 265nm ultraviolet excitation light, 335nm near-ultraviolet excitation light and 405nm blue-violet excitation light, were used to excite the blue calcite sample. The emission spectrum was collected in the wavelength range of 300-700nm using a spectrometer to obtain three sets of emission spectrum data under different excitation wavelengths. Among them, the 265nm excitation light mainly excites the rare earth ion emission centers, the 335nm excitation light mainly excites the manganese ion emission centers, and the 405nm excitation light mainly excites the lattice defect emission centers.

[0010] Step 3, Temperature gradient spectroscopy test: Place the sample stage in the variable temperature spectroscopy test system, and use a 265nm excitation wavelength to test the emission spectrum of the sample at seven temperature points: 80K, 120K, 160K, 200K, 240K, 280K and 320K, to obtain temperature gradient emission spectrum data, which is used to analyze the temperature quenching characteristics and thermal stability of the emission center.

[0011] Step 4, Time-Resolved Spectroscopic Acquisition: A pulsed laser excitation system was used to excite the blue calcite sample with a 265nm pulsed laser. Within a 0-10ms time window after excitation, 100 sets of time-resolved emission spectra were acquired at 0.1ms intervals. Fluorescence lifetime parameters for different luminescent centers were obtained by analyzing the emission decay curves. The fluorescence lifetime range for manganese ion luminescent centers was 0.3-1.5ms, for rare earth ion luminescent centers it was 0.5-3.0ms, and for defect luminescent centers it was 0.05-0.3ms.

[0012] Step 5, Application of the luminescence center identification algorithm: Based on the multidimensional spectral data obtained in steps 2 to 4, the luminescence center identification algorithm is applied for comprehensive analysis. This algorithm establishes an excitation wavelength dependence matrix, a temperature response characteristic matrix, and a fluorescence lifetime characteristic matrix, compares them with a standard luminescence center spectral database, identifies and distinguishes manganese ion luminescence centers, rare earth ion luminescence centers, and lattice defect luminescence centers in blue calcite, and calculates the relative contribution rate of each luminescence center to the total luminescence intensity.

[0013] Step 6, Spectral Deconvolution Analysis: Baseline correction and normalization are performed on the three sets of emission spectrum data obtained in Step 2. A Gaussian-Lorentz mixture function is used to deconvolve and fit the overlapping emission peaks, separating each independent emission peak. The peak position, full width at half maximum (FWHM), and integral intensity of each emission peak are determined. The fitting parameters are optimized using the least squares method to optimize the correlation coefficient between the fitted curve and the measured spectrum. ;

[0014] Step 7, Establishing the quantitative relationship of the reference samples: Prepare a series of standard blue calcite reference samples containing known manganese and rare earth elements, with manganese content ranging from [value missing]. The rare earth content range is The reference sample was tested and analyzed according to the process from step 1 to step 6. A quantitative calibration curve between luminescence intensity and luminescence center content was established, and the calibration equation was fitted using linear regression or polynomial regression methods.

[0015] Step 8, Quantitative Analysis of Unknown Samples: Following steps 1 to 6, complete the spectral testing and analysis of the blue calcite sample to be tested, obtain the integral intensity of the characteristic peaks of each luminescence center, substitute them into the quantitative calibration equation established in step 7, and calculate the content of luminescence centers such as manganese ions and rare earth ions in the sample. The quantitative detection sensitivity reaches [value missing]. The quantitative accuracy is over 95%;

[0016] Step 9, Comprehensive Evaluation of Luminescence Characteristics: Based on the analysis results of Steps 5 to 8, comprehensively evaluate the luminescence characteristics of blue calcite, including indicators such as dominant luminescence center type, luminescence intensity, chromaticity parameters, fluorescence quantum yield, and luminescence uniformity, and generate a comprehensive characterization report of the luminescence characteristics of blue calcite to provide a scientific basis for mineral identification, quality evaluation, and origin tracing.

[0017] Furthermore, in step 2, the multi-wavelength excitation spectrum acquisition uses a steady-state fluorescence spectrometer, the excitation light source is a 150W xenon lamp, the spectral bandwidth of both the excitation monochromator and the emission monochromator is set to 2nm, the emission spectrum scanning speed is 600nm / min, the photomultiplier tube operating voltage is 700V, and the measurement is repeated 3 times at each excitation wavelength to take the average value to improve the reliability of the data.

[0018] Furthermore, in step 3, the temperature gradient spectroscopy test uses a variable-temperature fluorescence spectroscopy system, which includes a closed-loop helium cooler, a temperature controller, and an optical fiber transmission path. The sample is tested under a vacuum level superior to... The test was conducted in a low-temperature chamber with a temperature control accuracy of ±0.5K. After each temperature point was stabilized for 10 minutes, spectral acquisition began. The thermal quenching activation energy was calculated by analyzing the change in luminescence intensity with temperature.

[0019] Furthermore, in step 4, the time-resolved spectral acquisition uses a pulsed laser as the excitation source with a pulse width of 10 ns and a repetition frequency of 20 Hz. The detection gating timing is controlled by a delay generator with a gate width of 0.05 ms. The emission decay curve is recorded using time-correlated single-photon counting technology or gating integration method. The decay curve is then subjected to multi-exponential fitting to obtain the fluorescence lifetime of each emission center.

[0020] Furthermore, the specific process of the luminescence center identification algorithm in step 5 is as follows: First, an excitation wavelength dependence matrix is ​​established, and the ratio of the sample luminescence intensity at three excitation wavelengths of 265 nm, 335 nm, and 405 nm is calculated. and manganese ion luminescent center The ratio ranges from 0.3 to 0.7, indicating the presence of rare earth ion luminescent centers. The ratio ranges from 1.5 to 3.0; then, a temperature response characteristic matrix is ​​established, and the ratio of luminescence intensity at 80K and 320K is calculated. manganese ion luminescent center The ratio ranges from 2.0 to 4.5, indicating the presence of rare earth ion luminescent centers. The ratio ranges from 1.2 to 2.0. Finally, a fluorescence lifetime characteristic matrix is ​​established, and the fluorescence lifetime parameters obtained by fitting the fluorescence decay curve are used to assign luminescent centers. The types and relative contents of each luminescent center are determined by combining the analysis results of the three characteristic matrices.

[0021] Furthermore, the Gaussian-Lorentz mixture function expression used in the spectral deconvolution analysis in step 6 is as follows: ,in wavelength The luminous intensity at that location Let be the peak height of the i-th emission peak. Let be the peak position of the i-th emission peak. Let be the full width at half maximum (FWHM) of the i-th emission peak, and m be the Gaussian-Lorentz mixing ratio coefficient, ranging from 0 to 1. The parameters are optimized by nonlinear least square fitting using the Levenberg-Marquardt algorithm.

[0022] Further, the preparation method of the reference sample in step 7 is as follows: pure colorless transparent calcite is selected as the base material, crushed to below 200 mesh, soaked in dilute hydrochloric acid solution for 12 hours to remove surface impurities, repeatedly rinsed with deionized water until neutral, and dried in an oven at 80℃ for 2 hours; manganese ion standard solution and rare earth ion standard solution are prepared respectively, and manganese ions or rare earth ions are introduced into the calcite lattice by chemical deposition or ion implantation to prepare a series of reference samples containing different concentrations of manganese ions or rare earth ions. At least 3 parallel samples are prepared for each concentration point, and the actual content of manganese and rare earth in the reference sample is verified by inductively coupled plasma mass spectrometry (ICP-MS).

[0023] Furthermore, the quantitative calibration equation in step 8 is established using the following method: the integrated intensity of the characteristic emission peak of manganese ions at 580 nm under an excitation wavelength of 265 nm. The x-axis represents the manganese content determined by ICP-MS. Using the ordinate as the vertical axis, a calibration curve is plotted and linear regression is performed to obtain the quantitative equation. ,in The slope Intercept, linear correlation coefficient Similarly, the integrated intensity of the characteristic emission peak of rare earth ions at 615 nm under an excitation wavelength of 265 nm. Establish rare earth content Quantitative equations linear correlation coefficient For unknown samples, the content of luminescent centers can be calculated by substituting the integral intensity of the characteristic peak into the corresponding quantitative equation.

[0024] Furthermore, the calculation method for the comprehensive evaluation index of luminescence characteristics in step 9 is as follows: the chromaticity coordinate parameters (x, y) are calculated using the CIE 1931 chromaticity system through integrated emission spectroscopy, and the fluorescence quantum yield is... The integrating sphere method was used to determine the spectra of the sample placed inside the integrating sphere, and the spectra of the sample directly irradiated by the excitation light on the inner wall of the integrating sphere were measured. and the spectrum of the sample after excitation light irradiation According to the formula Calculate the fluorescence quantum yield, where and The spectra of the excitation region under two measurement conditions are shown respectively. The luminescence uniformity is evaluated by scanning the sample surface at multiple points (at least 9 points) and calculating the relative standard deviation (RSD) of the luminescence intensity. RSD < 5% indicates good luminescence uniformity.

[0025] Furthermore, the standard luminescence center spectral database used in the luminescence center identification algorithm contains the following information: manganese ions of The characteristic emission peak of the transition is located at 570-590 nm, and the excitation wavelength dependence coefficient is... The fluorescence lifetime is 0.3-0.7, the temperature quenching coefficient is 2.0-4.5 ms, and the fluorescence quenching coefficient is 0.3-1.5 ms. Europium ions of The characteristic emission peak of the transition is located at 610-625 nm, and the excitation wavelength dependence coefficient is... The fluorescence lifetime is 0.5-3.0 ms, and the temperature quenching coefficient is 1.2-2.0. The emission peak at the carbonate defect center is located at 420-480 nm, and the excitation wavelength dependence coefficient is [missing value]. The fluorescence lifetime is 0.05-1.0, the temperature quenching coefficient is 4.0-8.0; by matching the spectral characteristic parameters of the sample to be tested with the standard parameters in the database, the accurate identification and classification of the luminescent center can be achieved.

[0026] The beneficial effects of this invention are as follows:

[0027] 1. By employing a comprehensive analysis process that combines multi-wavelength excitation with temperature gradient testing, we can obtain comprehensive information on the luminescence characteristics of blue calcite. The three excitation wavelengths of 265nm, 335nm, and 405nm are respectively targeted at different types of luminescence centers, enabling in-depth analysis of the luminescence mechanism. Temperature gradient testing reveals the thermal stability and temperature quenching law of the luminescence centers, enriching the dimensions of luminescence characteristic characterization.

[0028] 2. An innovative luminescence center identification algorithm was developed. By establishing an excitation wavelength dependence matrix, a temperature response feature matrix, and a fluorescence lifetime feature matrix, the algorithm accurately distinguishes manganese ion luminescence centers, rare earth ion luminescence centers, and lattice defect luminescence centers in blue calcite. This solves the technical problem that traditional methods cannot distinguish the coexistence of multiple luminescence centers, and the identification accuracy rate reaches over 98%.

[0029] 3. By introducing time-resolved spectroscopy, the fluorescence lifetime parameters of different luminescent centers are measured, providing a key criterion for the accurate attribution of luminescent centers. The time resolution reaches 0.1 ms, which can effectively distinguish different luminescent centers with fluorescence lifetime differences of more than 0.2 ms.

[0030] 4. A Gaussian-Lorentz mixture function was used to deconvolve the overlapping emission peaks, achieving accurate separation and quantification of complex emission spectra and fitting correlation coefficients. This significantly improves the accuracy and reliability of spectral analysis;

[0031] 5. A quantitative analysis framework based on reference samples was established, and the precise quantitative relationship between luminescence intensity and the content of key elements was determined, improving the detection sensitivity of manganese and rare earth elements to [value missing]. The level is improved by 2-3 orders of magnitude compared to traditional methods, and the quantitative accuracy is improved to over 95%, meeting the needs of high-precision quantitative analysis;

[0032] 6. A complete comprehensive evaluation system for the luminescence properties of blue calcite is provided, including multiple indicators such as luminescence center type, luminescence intensity, color coordinates, fluorescence quantum yield and luminescence uniformity, which can provide comprehensive and reliable technical support for scientific research, mineral identification, quality evaluation, origin tracing and gemological applications of blue calcite;

[0033] 7. This method is simple to operate, fast to test, and has good repeatability. The complete test and analysis time for a single sample is within 2 hours, making it suitable for high-throughput analysis of batch samples. It has been successfully applied to the analysis of multiple geological and gemstone samples and has achieved good application results. Detailed Implementation

[0034] The technical solution of the present invention will be clearly and completely described below through specific embodiments. The described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] It should be noted that in the description of this invention, the terms "upper", "lower", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship, and are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0036] Example 1

[0037] This embodiment provides a complete implementation process for the precise characterization and quantitative analysis of the luminescence spectrum of blue calcite, and conducts a comprehensive analysis of a natural blue calcite sample collected from Hubei Province.

[0038] Sample Preparation: After cleaning the surface of the blue calcite sample, grind it to a particle size of less than 200 mesh using an agate mortar and pestle, then dry it in an 80℃ drying oven for 2 hours to remove adsorbed water. Weigh 50 mg of the ground sample powder and press it into a circular test sample disc with a diameter of 10 mm and a thickness of 1 mm using a tablet press under a pressure of 10 MPa. Fix the sample disc on the sample stage, ensuring the sample surface is flat and smooth, ready for testing.

[0039] Multi-wavelength excitation spectral acquisition: A Hitachi F-7000 steady-state fluorescence spectrometer was used for testing, equipped with a 150W xenon lamp as the excitation source. First, 265 nm was used as the excitation wavelength, with the spectral bandwidth of both the excitation and emission monochromators set to 2 nm. The emission spectral scanning range was 300-700 nm, the scanning speed was 600 nm / min, and the photomultiplier tube operating voltage was 700 V. At this excitation wavelength, the sample exhibited a moderate-intensity blue emission peak at 450 nm, a weak green emission peak at 550 nm, and a strong orange-red emission peak at 615 nm. Then, 335 nm was used as the excitation wavelength, with other test parameters remaining constant. At this excitation wavelength, the sample exhibited a strong yellow-green emission peak at 580 nm, significantly higher than the emission intensity under 265 nm excitation. Finally, 405 nm was used as the excitation wavelength, and the sample exhibited a moderate-intensity blue emission peak at 460 nm. Measurements were repeated three times at each excitation wavelength, and the average value was taken to obtain three sets of stable and reliable emission spectral data.

[0040] Temperature gradient spectroscopy: The sample was transferred to an Edinburgh FLS1000 variable-temperature fluorescence spectroscopy system, equipped with an Advanced Research Systems DE202 closed-loop helium cooler and a Lake Shore 336 temperature controller. The sample was fixed on the copper sample stage of the low-temperature chamber, and the chamber was evacuated to a vacuum level using a vacuum pump. The sample was cooled to 80K using a cooler with a temperature control accuracy of ±0.5K. After stabilizing for 10 minutes, the emission spectrum was collected using an excitation wavelength of 265nm. The temperature was then sequentially increased to 120K, 160K, 200K, 240K, 280K, and 320K, with the emission spectrum collected after stabilizing for 10 minutes at each temperature. The results showed that as the temperature increased from 80K to 320K, the intensity of the orange-red emission peak at 615nm gradually decreased, and the intensity ratio... The intensity of the yellow-green emission peak at 580 nm is 1.65, and the decrease is more pronounced, with an intensity ratio of 1.65. The intensity of the blue light emission peak at 460 nm decreased most significantly, with a value of 3.28. The value is 6.45, indicating that the three luminescent centers have different temperature quenching characteristics.

[0041] Time-resolved spectral acquisition: A time-resolved fluorescence spectroscopy system equipped with an Nd:YAG third-harmonic pulsed laser was used for testing. The laser wavelength was 266 nm (close to 265 nm), the pulse width was 10 ns, and the repetition frequency was 20 Hz. The detection gating timing was controlled using a Stanford SR400 delay generator with a gate width of 0.05 ms. One hundred sets of time-resolved emission spectra were acquired at 0.1 ms intervals within a 0-10 ms time window after the excitation pulse. Analysis of the emission decay curves at different wavelengths revealed a fluorescence lifetime of 1.85 ms for the emission decay curve measured at 615 nm, fitted with a single exponential function. The emission decay curve measured at 580 nm required a double exponential function fitting, yielding a short-lived component of 0.68 ms (65%) and a long-lived component of 1.12 ms (35%). The emission decay curve measured at 460 nm yielded a fluorescence lifetime of 0.15 ms. These fluorescence lifetime parameters provide crucial criteria for the accurate attribution of emission centers.

[0042] Application of the luminescence center identification algorithm: Based on the above multidimensional spectral data, a comprehensive analysis is performed using the luminescence center identification algorithm. First, an excitation wavelength dependence matrix is ​​established, and the emission peak at 615 nm is calculated. The ratio is 2.35, with an emission peak at 580nm. The ratio is 0.52, with an emission peak at 460 nm. The ratio is 0.73. Then, the temperature response characteristic matrix is ​​established, showing the emission peak at 615nm. The ratio is 1.65, with an emission peak at 580 nm. The ratio is 3.28, with an emission peak at 460nm. The ratio was 6.45. Finally, a fluorescence lifetime characteristic matrix was established. The fluorescence lifetime of the 615 nm emission peak was 1.85 ms, the 580 nm emission peak was 0.68–1.12 ms, and the 460 nm emission peak was 0.15 ms. These characteristic parameters were compared with a standard luminescence center spectral database, and the identification result was that the 615 nm emission peak belonged to europium ions. of The transition, with the 580nm emission peak belonging to manganese ions. of The emission peak at 460 nm is attributed to the carbonate defect center. The calculated relative contributions of each luminescent center to the total luminescence intensity are: europium ions 48%, manganese ions 37%, and defect centers 15%.

[0043] Spectral deconvolution analysis: Baseline correction was performed on the emission spectrum data obtained at an excitation wavelength of 265 nm. Background signal was subtracted using a polynomial fitting method, and then the spectrum was normalized to ensure the maximum peak intensity was 1.0. A Gaussian-Lorentz mixture function was used. ,

[0044] The overlapping emission peaks were deconvolved and fitted, with the Gaussian-Lorentz mixing ratio coefficient m=0.7. Nonlinear least-squares fitting was performed using the Levenberg-Marquardt algorithm, successfully separating the complex emission spectrum into five independent emission peaks located at 450nm, 485nm, 580nm, 615nm, and 650nm. The fitting parameters for each peak are shown in the table below.

[0045]

[0046] Correlation coefficient between the fitted curve and the measured spectrum The value of 0.988 indicates that the deconvolution analysis performed well. Through deconvolution analysis, accurate separation and quantization of complex emission spectra were successfully achieved.

[0047] Establishment of quantitative relationships for reference samples: Pure, colorless, and transparent calcite from Iceland was selected as the substrate material. It was pulverized to below 200 mesh, soaked in 0.1 mol / L dilute hydrochloric acid solution for 12 hours to remove surface impurities, then repeatedly rinsed with deionized water until pH=7, and dried in an oven at 80℃ for 2 hours. Concentrations of [missing information] were prepared separately. , , , , , , , , The manganese ion standard solution and concentration are , , , , , , Europium ion standard solutions were prepared. Manganese or europium ions were introduced into the calcite lattice using a chemical deposition method. Specifically, 10g of calcite base powder was added to 50mL of standard solution, and the mixture was stirred in an 80℃ water bath for 6 hours. After centrifugation, the samples were washed three times with deionized water and dried in an 80℃ oven for 2 hours to obtain a series of reference samples. Three parallel samples were prepared for each concentration point. The actual content of manganese and europium in the reference samples was verified using a Thermo iCAP RQ inductively coupled plasma mass spectrometer. The deviation between the measured results and the theoretical addition amount was within ±3%. All reference samples were tested and analyzed according to the method of this invention, with the integrated intensity of the characteristic emission peak of manganese ions at 580nm under an excitation wavelength of 265nm as the measurement. The x-axis represents the manganese content determined by ICP-MS. Using the ordinate as the vertical axis, a calibration curve is plotted and linear regression is performed to obtain the quantitative equation. linear correlation coefficient Similarly, the integrated intensity of the characteristic emission peak of europium ions at 615 nm under an excitation wavelength of 265 nm is... Establish europium content Quantitative equations linear correlation coefficient The establishment of quantitative calibration curves lays a solid foundation for the accurate quantitative analysis of unknown samples.

[0048] Quantitative analysis of unknown samples: For the blue calcite sample from Hubei in this embodiment, the integrated intensity of the characteristic emission peak of manganese ions at 580 nm was obtained based on spectral deconvolution analysis. The manganese content was calculated by substituting it into the quantitative equation. The integrated intensity of the characteristic emission peak of europium ions at 615 nm The europium content was calculated by substituting it into the quantitative equation. To verify the accuracy of the quantitative results, the sample was independently measured using ICP-MS, and the manganese content was found to be... europium content is The relative deviations between the quantitative results obtained by this method and the results obtained by ICP-MS were 3.9% and 3.6%, respectively, and the quantitative accuracy reached over 96%, demonstrating that this method has high-precision quantitative analysis capabilities.

[0049] Comprehensive Evaluation of Luminescent Properties: Based on the above analysis results, the luminescent properties of this blue calcite sample were comprehensively evaluated. The dominant luminescent centers were europium and manganese ions, with relative contribution rates of 48% and 37%, respectively, while the defect center contributed a smaller 15%. Under 265 nm excitation, the maximum emission wavelength of the sample was 615 nm, belonging to the orange-red light region. According to the CIE 1931 colorimetric system, the color coordinates were calculated as x=0.528, y=0.398, corresponding to an orange-red color, using integrated emission spectroscopy. The fluorescence quantum yield was determined using the integrating sphere method. The sample was placed inside an integrating sphere with a diameter of 150 mm. The spectra of the sample directly irradiated by excitation light and the spectra of the sample after excitation light irradiation were measured. The fluorescence quantum yield was calculated using the formula. Nine-point scanning tests were performed on the sample surface, and the measured luminescence intensities at each point were 18.1, 18.5, 17.8, 18.3, 18.6, 17.9, 18.4, 18.2, and 18.5, with an average value of 18.26 and a standard deviation of 0.28. The relative standard deviation (RSD) was 1.53% (<5%), indicating good luminescence uniformity of the sample. Based on the above evaluation indicators, this blue calcite sample exhibits excellent luminescence properties, with europium and manganese ions as the dominant luminescence centers, an orange-red luminescence color, high fluorescence quantum yield, and good luminescence uniformity, thus possessing high gemological application value.

[0050] Example 2

[0051] This embodiment uses luminescence spectroscopy to characterize and quantitatively analyze a blue calcite sample from Brazil, focusing on verifying the applicability of this method to samples from different origins.

[0052] Sample preparation: The Brazilian blue calcite sample was ground to a particle size of less than 200 mesh and dried in an oven at 80℃ for 2 hours. 50 mg of the sample was weighed and pressed into a test sample piece with a diameter of 10 mm and a thickness of 1 mm, and fixed on the sample stage for testing.

[0053] Multi-wavelength excitation spectral acquisition: A Hitachi F-7000 steady-state fluorescence spectrometer was used to measure the emission spectra of the samples at three excitation wavelengths: 265 nm, 335 nm, and 405 nm. Under 265 nm excitation, emission peaks appeared at 420 nm, 480 nm, and 590 nm; under 335 nm excitation, the intensity of the emission peak at 590 nm was significantly enhanced; and under 405 nm excitation, the blue emission peaks at 420 nm and 480 nm were significantly enhanced. Measurements were repeated three times at each excitation wavelength, and the average value was taken.

[0054] Temperature gradient spectroscopy: The emission spectra of the samples were measured using an Edinburgh FLS1000 variable-temperature fluorescence spectroscopy system at seven temperature points: 80K, 120K, 160K, 200K, 240K, 280K, and 320K. The results showed that the emission peak intensities at 420nm, 480nm, and 590nm all decreased with increasing temperature, but the magnitude of the decrease varied. The intensity of the emission peak at 420nm... The ratio is 5.82, with an emission peak at 480 nm. The ratio is 4.35, with an emission peak at 590 nm. The ratio is 2.87.

[0055] Time-resolved spectral acquisition: Using a 266nm pulsed laser excitation system, 100 sets of time-resolved emission spectra were acquired within a 0-10ms time window after excitation. Analysis of the emission decay curves revealed a fluorescence lifetime of 0.12ms at 420nm and 0.22ms at 480nm. The emission decay curve at 590nm required a double exponential function fitting to obtain a short-lived component of 0.58ms (72%) and a long-lived component of 0.95ms (28%).

[0056] Application of luminescence center identification algorithm: Comprehensive analysis based on multidimensional spectral data. Excitation wavelength dependence matrix: emission peak at 420nm. The ratio is 0.68, and the emission peak at 480nm is... The ratio is 0.81, and the emission peak at 590 nm is... The ratio is 0.48. Temperature response characteristic matrix: emission peak at 420nm. The ratio is 5.82, with an emission peak at 480 nm. The ratio is 4.35, with an emission peak at 590 nm. The ratio is 2.87. Fluorescence lifetime characteristic matrix: the fluorescence lifetime of the 420nm emission peak is 0.12ms, the 480nm emission peak is 0.22ms, and the 590nm emission peak is 0.58-0.95ms. Comparison with the standard luminescence center spectral database reveals that the 420nm and 480nm emission peaks belong to carbonate defect centers, and the 590nm emission peak belongs to manganese ions. The calculated relative contribution rates of each luminescent center to the total luminescence intensity are as follows: defect centers 52% (420nm peak 32%, 480nm peak 20%), manganese ions 48%.

[0057] Spectral deconvolution analysis: The emission spectrum at an excitation wavelength of 265 nm was baseline corrected and normalized. Deconvolution fitting was performed using a Gaussian-Lorentz mixture function, successfully separating the emission into four independent peaks located at 420 nm, 480 nm, 590 nm, and 640 nm. The correlation coefficient between the fitted curve and the measured spectrum was calculated. The value is 0.985. The fitting parameters for each peak are shown in the table below:

[0058]

[0059] Quantitative analysis of unknown samples: The integrated intensity of the characteristic emission peak of manganese ions at 590 nm was obtained based on spectral deconvolution analysis. Since the peak position differs slightly from the 580nm peak position in the standard quantitative equation, peak position correction is required, with a correction factor of [missing value]. The corrected integral intensity is The manganese content was calculated by substituting it into the quantitative equation. Since no obvious europium ion emission peak was detected in the sample, the europium content was below the detection limit. The sample was independently determined using ICP-MS, and the manganese content was found to be... The relative deviation between the quantitative results of this method and the ICP-MS results was 4.5%, and the quantitative accuracy reached 95.5%.

[0060] Comprehensive evaluation of luminescence properties: The dominant luminescence centers of this Brazilian blue calcite sample are manganese ions (48%) and defect centers (52%), with no significant rare earth ion luminescence detected. Under 265 nm excitation, the maximum emission wavelength of the sample is 590 nm, belonging to the yellow-green light region. The calculated color coordinates are x=0.418, y=0.485, corresponding to a yellow-green color. Fluorescence quantum yield... The luminescence intensity was slightly lower than that of the sample in Example 1. A 9-point scan test showed a relative standard deviation (RSD) of 2.87% (<5%), indicating good luminescence uniformity. This sample exhibited yellow-green luminescence, dominated by manganese ions and defect centers, a significantly different color from the orange-red luminescence of Example 1. This reflects the differences in luminescence characteristics of blue calcite from different origins, providing important evidence for tracing its origin.

[0061] Example 3

[0062] This embodiment uses luminescence spectroscopy to characterize and quantitatively analyze a light blue calcite sample collected from Mexico, verifying the detection capability of this method for samples with low concentrations of luminescent centers.

[0063] Sample preparation: The light blue Mexican calcite sample was ground to a particle size of less than 200 mesh, dried in an oven at 80℃ for 2 hours, and 50 mg of sample was weighed and pressed into a test sample piece, which was then fixed on the sample stage for testing.

[0064] Multi-wavelength excitation spectral acquisition: A Hitachi F-7000 steady-state fluorescence spectrometer was used for testing. Under 265 nm excitation, the sample exhibited weak luminescence intensity, with faint emission peaks at 450 nm, 580 nm, and 610 nm. Under 335 nm excitation, the intensity of the emission peak at 580 nm slightly increased; under 405 nm excitation, the blue light emission peak at 450 nm was relatively enhanced. To improve the signal-to-noise ratio, the photomultiplier tube operating voltage was increased to 800 V, and the scan speed was reduced to 300 nm / min. Measurements were repeated five times at each excitation wavelength, and the average value was taken.

[0065] Temperature gradient spectroscopy testing: The emission spectra of the sample were tested at seven temperature points: 80K, 120K, 160K, 200K, 240K, 280K, and 320K. Due to the weak emission intensity of the sample, the operating voltage of the photomultiplier tube was increased to 850V to improve detection sensitivity. The test results showed that the emission peak intensities at 450nm, 580nm, and 610nm all decreased with increasing temperature, and the intensity of the emission peak at 450nm decreased further. The ratio is 7.15, with an emission peak at 580nm. The ratio is 3.68, with an emission peak at 610 nm. The ratio is 1.82.

[0066] Time-resolved spectral acquisition: Using a 266nm pulsed laser excitation system, 100 sets of time-resolved emission spectra were acquired within a 0-10ms time window after excitation. Analysis of the emission decay curves revealed a fluorescence lifetime of 0.18ms at 450nm, 0.72ms at 580nm, and 1.68ms at 610nm.

[0067] Application of luminescence center identification algorithm: Comprehensive analysis based on multidimensional spectral data. Excitation wavelength dependence matrix: emission peak at 450nm. The ratio is 0.75, with an emission peak at 580 nm. The ratio is 0.55, and the emission peak at 610 nm is... The ratio is 2.18. Temperature response characteristic matrix: emission peak at 450nm. The ratio is 7.15, with an emission peak at 580nm. The ratio is 3.68, with an emission peak at 610 nm. The ratio is 1.82. Fluorescence lifetime characteristic matrix: the fluorescence lifetime of the 450nm emission peak is 0.18ms, the 580nm emission peak is 0.72ms, and the 610nm emission peak is 1.68ms. Comparison with the standard luminescence center spectral database reveals that the 450nm emission peak belongs to a carbonate defect center, and the 580nm emission peak belongs to a manganese ion. The emission peak at 610 nm belongs to europium ions. The calculated relative contribution rates of each luminescent center to the total luminescence intensity are as follows: defect centers 38%, manganese ions 35%, and europium ions 27%.

[0068] Spectral deconvolution analysis: The emission spectrum at an excitation wavelength of 265 nm was baseline-corrected and normalized. Deconvolution fitting was performed using a Gaussian-Lorentz mixture function, successfully separating the emission into three independent peaks located at 450 nm, 580 nm, and 610 nm. The correlation coefficient between the fitted curve and the measured spectrum was analyzed. The value is 0.992. The fitting parameters for each peak are shown in the table below:

[0069]

[0070] Quantitative analysis of unknown samples: The integrated intensity of the characteristic emission peak of manganese ions at 580 nm was obtained based on spectral deconvolution analysis. The manganese content was calculated by substituting it into the quantitative equation. The integrated intensity of the characteristic emission peak of europium ions at 610 nm Since the peak position differs slightly from the 615nm peak position in the standard quantitative equation, peak position correction is required, with a correction factor of [missing value]. The corrected integral intensity is The europium content was calculated by substituting it into the quantitative equation. The manganese content of this sample was determined independently using ICP-MS to be [value missing]. europium content is The relative deviations between the quantitative results obtained by this method and those obtained by ICP-MS were 3.4% and 3.1%, respectively, with a quantitative accuracy exceeding 96%. The contents of manganese and europium in this sample were both within [the specified range]. The results demonstrate that this method has good detection capability for samples with low concentrations of luminescent centers, and the detection sensitivity reaches [value missing]. level.

[0071] Comprehensive evaluation of luminescence properties: The dominant luminescence centers of this light blue Mexican calcite sample are defect centers (38%), manganese ions (35%), and europium ions (27%), with relatively similar relative contribution rates among the three luminescence centers. Under 265 nm excitation, the sample's main emission wavelength covers the range of 450-610 nm, exhibiting composite luminescence characteristics. The calculated color coordinates are x=0.382, y=0.425, corresponding to a blue-green color. Fluorescence quantum yield... The fluorescence intensity was lower than that of the samples in Examples 1 and 2, reflecting the lower fluorescence efficiency of the low-concentration luminescent centers. The relative standard deviation (RSD) of the luminescence intensity obtained from the 9-point scan test was 4.23% (<5%), indicating good luminescence uniformity. This sample exhibited a blue-green luminescence with weak intensity, characterized by a composite luminescent center, showing a significant difference from the samples in Examples 1 and 2.

[0072] Comparative Example 1

[0073] This comparative example uses traditional single-wavelength room-temperature fluorescence spectroscopy to analyze the Hubei blue calcite sample from Example 1 to verify the advantages of the method of the present invention.

[0074] The emission spectrum of the samples was tested using a single excitation wavelength of 365 nm at room temperature (25℃). The results showed a complex broadband characteristic in the emission spectrum, with multiple overlapping emission peaks in the 400-650 nm range, making it difficult to accurately distinguish the position and intensity of each peak. Due to the lack of multi-wavelength excitation and temperature gradient test data, the type of emission center could not be accurately identified. Attempts were made to perform peak fitting on the emission spectrum, but the reliability of the fitting results was poor due to the lack of fluorescence lifetime information provided by time-resolved spectroscopy, resulting in a low correlation coefficient. The value is only 0.82, far lower than the 0.988 of the method of this invention. In terms of quantitative analysis, since the luminescence contributions of manganese ions and europium ions cannot be accurately distinguished, the total content of luminescent centers can only be estimated to be approximately... The total content (manganese + europium) determined by ICP-MS was compared with that of other methods. Compared to the previous method, the relative deviation reached 9.3%, and the quantitative accuracy was only 90.7%, significantly lower than the over 96% of the method of this invention. The comparative results show that traditional single-wavelength room-temperature fluorescence spectroscopy, due to the lack of multidimensional spectral information and systematic analysis algorithms, is significantly inferior to the method of this invention in terms of luminescence center identification and quantitative analysis.

[0075] Comparative Example 2

[0076] In this comparative example, X-ray fluorescence spectrometry (XRF) was used to perform elemental quantitative analysis on the Hubei blue calcite sample from Example 1 to verify the advantages of the method of the present invention in terms of sensitivity.

[0077] The sample was tested using a Bruker S8 TIGER X-ray fluorescence spectrometer, equipped with a 4kW X-ray tube and various analytical crystals. The results showed a weak signal at the Mn Kα line (5.899 keV), but the signal intensity was close to the instrument's detection limit. After repeated measurements and data processing, the estimated manganese content was approximately [value missing]. , compared with ICP-MS measured values The results were close, with a relative deviation of 5.1%. However, no significant signal was detected at the Eu Lα line (5.846 keV), indicating that the europium content was below the detection limit of XRF (approximately). (At high levels), it is impossible to accurately quantify europium. Comparative results show that while XRF can perform semi-quantitative analysis of higher concentrations of manganese, it is less effective for... The sensitivity for europium, a rare earth element, is insufficient at low levels, with a detection limit of approximately [insert value here]. The level, compared to the detection sensitivity of the method of the present invention ( The XRF method is 2-3 orders of magnitude lower than the average. Furthermore, it can only provide the total elemental content, cannot distinguish between luminescent and non-luminescent centers, and cannot provide information on luminescence characteristics, thus limiting its application.

[0078] Comparative Example 3

[0079] This comparative example uses infrared absorption spectroscopy to analyze the Hubei blue calcite sample in Example 1 to verify the unique advantages of the method of the present invention in characterizing luminescence properties.

[0080] Samples were prepared using a Thermo Nicolet 6700 Fourier transform infrared spectrometer and the KBr pellet method. Infrared absorption spectra were collected within the wavenumber range. Test results show that... and Calcite appeared at the location Characteristic absorption peaks, in and A weak absorption peak for moisture was observed nearby, but no characteristic absorption peaks for manganese or rare earth ions were observed. Infrared spectroscopy can only provide information on molecular vibrations and cannot obtain information on electronic transitions at the luminescent center; therefore, it cannot be used to characterize luminescence properties. Infrared spectroscopy also cannot distinguish between luminescent and non-luminescent centers and cannot provide luminescence performance parameters such as luminescence intensity, fluorescence lifetime, and chromaticity coordinates. Comparative results show that infrared absorption spectroscopy is based on a completely different analytical principle. Although it can be used for the structural characterization of minerals and the quantitative analysis of certain components, it is not suitable for the precise characterization and quantitative analysis of the luminescence properties of blue calcite, and has fundamental limitations compared to the method of this invention in this application field.

[0081] The results of Examples 1-3 and Comparative Examples 1-3 show that the precise characterization and quantitative analysis method for the luminescence spectrum of blue calcite provided by this invention, through a comprehensive analysis process combining multi-wavelength excitation and temperature gradient testing, and employing luminescence center identification algorithms, time-resolved spectroscopy, and spectral deconvolution analysis techniques, achieves comprehensive characterization and high-precision quantitative analysis of the luminescence characteristics of blue calcite. This method can accurately identify multiple luminescence centers such as manganese ions, rare earth ions, and defect centers, precisely separate overlapping luminescence peaks, establish a quantitative relationship between luminescence intensity and luminescence center content, and achieve a detection sensitivity of [missing information]. This method achieves a quantitative accuracy of over 95%, significantly outperforming traditional single-wavelength fluorescence spectroscopy, X-ray fluorescence spectroscopy, and infrared absorption spectroscopy. It is simple to operate, rapid, and highly repeatable, suitable for analyzing blue calcite samples from different origins and with varying luminescent properties. It has been successfully applied in mineral identification, quality evaluation, and origin tracing, achieving excellent results and providing crucial technical support for the scientific research and gemological applications of blue calcite.

[0082] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for precise characterization and quantitative analysis of the luminescence spectrum of blue calcite, characterized in that, Includes the following steps: Step 1, Sample preparation: Grind the blue calcite sample to a particle size of less than 200 mesh, dry it in an oven at 80℃ for 2 hours, weigh 50mg of the sample and compress it into a test sample tablet with a diameter of 10mm and a thickness of 1mm. Step 2, Multi-wavelength excitation spectrum acquisition: The blue calcite sample was excited with three excitation wavelengths of 265nm, 335nm and 405nm respectively, and the emission spectrum was acquired in the wavelength range of 300-700nm to obtain three sets of emission spectrum data under different excitation wavelengths. Step 3, Temperature gradient spectroscopy test: At seven temperature points of 80K, 120K, 160K, 200K, 240K, 280K and 320K, the emission spectrum of the sample is tested using an excitation wavelength of 265nm to obtain temperature gradient emission spectrum data. Step 4, Time-resolved spectral acquisition: Using a pulsed laser excitation system, the sample is excited with a 265nm pulsed laser. Within a time window of 0-10ms after excitation, 100 sets of time-resolved emission spectra are acquired at 0.1ms intervals. The fluorescence lifetime parameters of different emission centers are obtained by analyzing the emission decay curves. Step 5, Application of the luminescence center identification algorithm: Based on the multidimensional spectral data obtained in steps 2 to 4, by establishing the excitation wavelength dependence matrix, temperature response characteristic matrix and fluorescence lifetime characteristic matrix, the algorithm identifies and distinguishes manganese ion luminescence centers, rare earth ion luminescence centers and lattice defect luminescence centers in blue calcite. Step 6, Spectral deconvolution analysis: Baseline correction and normalization are performed on the emission spectrum data obtained in Step 2. The Gaussian-Lorentz mixture function is used to deconvolve and fit the overlapping emission peaks to separate each independent emission peak and determine the peak position, half width at half maximum and integral intensity of each emission peak. Step 7, Establishing the quantitative relationship of the reference sample: Prepare a series of standard blue calcite reference samples with known manganese and rare earth contents, test and analyze the reference samples according to the process of steps 1 to 6, and establish a quantitative calibration curve between luminescence intensity and luminescence center content; Step 8, Quantitative analysis of unknown samples: The blue calcite sample to be tested is subjected to spectral testing and analysis according to the process of steps 1 to 6. The integral intensity of the characteristic peak of each luminescence center is obtained and substituted into the quantitative calibration equation established in step 7 to calculate the content of luminescence centers such as manganese ions and rare earth ions in the sample. Step 9, Comprehensive evaluation of luminescence properties: Based on the analysis results of steps 5 to 8, comprehensively evaluate the luminescence properties of blue calcite, including the dominant luminescence center type, luminescence intensity, chromaticity parameters, fluorescence quantum yield, and luminescence uniformity.

2. The method for precise characterization and quantitative analysis of the luminescence spectrum of blue calcite according to claim 1, characterized in that: In step 2, the multi-wavelength excitation spectrum acquisition was performed using a steady-state fluorescence spectrometer. The excitation light source was a 150W xenon lamp. The spectral bandwidth of both the excitation monochromator and the emission monochromator was set to 2nm. The emission spectrum scanning speed was 600nm / min. The photomultiplier tube operating voltage was 700V. Each excitation wavelength was measured three times and the average value was taken.

3. The method for precise characterization and quantitative analysis of the luminescence spectrum of blue calcite according to claim 1, characterized in that: In step 3, the temperature gradient spectroscopy test uses a variable-temperature fluorescence spectroscopy system, and the sample is subjected to a vacuum level superior to that of the standard temperature. The test was conducted in a low-temperature chamber with a temperature control accuracy of ±0.5K. Spectral acquisition began after each temperature point had been stable for 10 minutes.

4. The method for precise characterization and quantitative analysis of the luminescence spectrum of blue calcite according to claim 1, characterized in that: In step 4, time-resolved spectral acquisition uses a pulsed laser as the excitation source with a pulse width of 10 ns and a repetition frequency of 20 Hz. The detection gating timing is controlled by a delay generator with a gate width of 0.05 ms. The emission decay curve is recorded using time-correlated single-photon counting technology or gating integration method.

5. The method for precise characterization and quantitative analysis of the luminescence spectrum of blue calcite according to claim 1, characterized in that: The specific process of the luminescence center identification algorithm in step 5 is as follows: establish an excitation wavelength dependence matrix, and calculate the ratio of sample luminescence intensity at excitation wavelengths of 265nm, 335nm, and 405nm. and Establish a temperature response characteristic matrix and calculate the ratio of luminescence intensity at 80K and 320K temperatures. A fluorescence lifetime characteristic matrix was established, and the fluorescence lifetime parameters obtained by fitting the fluorescence decay curve were used to assign luminescent centers. The types and relative contents of each luminescent center were determined by combining the analysis results of the three characteristic matrices.

6. The method for precise characterization and quantitative analysis of the luminescence spectrum of blue calcite according to claim 1, characterized in that: The expression for the Gaussian-Lorentz mixture function used in the spectral deconvolution analysis in step 6 is as follows: ,in wavelength The luminous intensity at that location Let be the peak height of the i-th emission peak. Let be the peak position of the i-th emission peak. Let m be the full width at half maximum (FWHM) of the i-th emission peak, and m be the Gaussian-Lorentz mixing ratio coefficient, ranging from 0 to 1. The parameters are optimized using a nonlinear least-squares fitting algorithm based on the Levenberg-Marquardt algorithm to achieve the correlation coefficient between the fitted curve and the measured spectrum. .

7. The method for precise characterization and quantitative analysis of the luminescence spectrum of blue calcite according to claim 1, characterized in that: The preparation method of the reference sample in step 7 is as follows: Pure, colorless, transparent calcite is selected as the base material, pulverized to below 200 mesh, soaked in dilute hydrochloric acid solution for 12 hours, repeatedly rinsed with deionized water until neutral, and dried in an 80℃ oven for 2 hours; manganese ion standard solutions and rare earth ion standard solutions are prepared, and manganese ions or rare earth ions are introduced into the calcite lattice using chemical deposition or ion implantation methods to prepare a series of reference samples containing different concentrations of manganese ions or rare earth ions, with manganese content ranging from [specific range missing]. The rare earth content range is The actual content of manganese and rare earth elements in the reference sample was verified using inductively coupled plasma mass spectrometry.

8. The method for precise characterization and quantitative analysis of the luminescence spectrum of blue calcite according to claim 1, characterized in that: The quantitative calibration equation in step 8 is established using the following method: the integrated intensity of the characteristic emission peak of manganese ions at 580 nm under an excitation wavelength of 265 nm. The x-axis represents the manganese content determined by inductively coupled plasma mass spectrometry. Using the ordinate as the vertical axis, a calibration curve is plotted and linear regression is performed to obtain the quantitative equation. linear correlation coefficient The integrated intensity of the characteristic emission peak of rare earth ions at 615 nm under an excitation wavelength of 265 nm. Establish rare earth content Quantitative equations linear correlation coefficient Quantitative detection sensitivity reaches The quantitative accuracy is over 95%.

9. The method for precise characterization and quantitative analysis of the luminescence spectrum of blue calcite according to claim 1, characterized in that: The calculation method for the comprehensive evaluation index of luminescence properties in step 9 is as follows: the chromaticity coordinate parameters (x, y) are calculated using the CIE 1931 chromaticity system through integrated emission spectroscopy; the fluorescence quantum yield... The integrating sphere method was used to determine the spectra of the sample placed inside the integrating sphere, and the spectra of the sample directly irradiated by the excitation light on the inner wall of the integrating sphere were measured. and the spectrum of the sample after excitation light irradiation According to the formula The fluorescence quantum yield was calculated; the luminescence uniformity was evaluated by calculating the relative standard deviation (RSD) of the luminescence intensity through multi-point scanning tests on the sample surface.

10. The method for precise characterization and quantitative analysis of the luminescence spectrum of blue calcite according to claim 5, characterized in that: The standard luminescence center spectral database used in the luminescence center identification algorithm contains the following information: manganese ions The characteristic emission peak is located at 570-590 nm, and the excitation wavelength dependence coefficient is... The fluorescence lifetime is 0.3-0.7, the temperature quenching coefficient is 0.3-1.5 ms, and the fluorescence quenching coefficient is 0.3-0.

7. The range is 2.0-4.5; the characteristic emission peaks of rare earth ions are located at 610-625 nm, and the excitation wavelength dependence coefficient is 2.0-4.

5. The fluorescence lifetime is 0.5-3.0 ms, and the temperature quenching coefficient is 1.5-3.0 ms. The value is 1.2-2.0; the emission peak at the defect center is located at 420-480 nm, and the excitation wavelength dependence coefficient is 1.2-2.

0. The fluorescence lifetime is 0.05-1.0, and the temperature quenching coefficient is 0.05-0.3 ms. The range is 4.0-8.0.

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