Inversion method for composition of black carbon aerosol encapsulation layer under different particle sizes

Abstract

This invention relates to an inversion method for the composition of black carbon aerosol coatings of different particle sizes, comprising: sampling black carbon aerosol coatings and screening out black carbon particles with specific electromobility particle sizes; measuring the scattering coefficient, absorption coefficient, and single scattering albedo in multiple wavelength bands; passing the black carbon particles into a thermal ablation tube to remove the black carbon aerosol coating, and then measuring the electromobility particle size of the black carbon core; establishing a lookup table of optical property calculation results; constructing an objective function and searching the lookup table of optical property calculation results to obtain the equivalent complex refractive index of the coating that minimizes the objective function; calculating the complex refractive index of the coating after uniformly mixing different coating components according to different volume fractions based on various theories, and constructing a lookup table of complex refractive index calculation results; constructing an objective function, and searching the lookup table of refractive index calculation results based on the equivalent complex refractive index of the coating to obtain the volume fractions corresponding to different coating components that minimize the objective function.

Description

Technical Field

[0001] This invention relates to an aerosol composition inversion technique, specifically a method for inverting the composition of black carbon aerosol encapsulation layers with different particle sizes. Background Technology

[0002] Black carbon aerosols are a significant component of atmospheric aerosols, exhibiting strong light absorption and exerting complex influences on atmospheric radiation balance and global warming. The incomplete combustion of biomass and fossil fuels leads to the large-scale emission of black carbon. Influenced by the combustion materials and combustion states, black carbon aerosols manifest as exposed carbon particle clusters or encapsulated structures containing inorganic salts or organic matter produced during combustion. When black carbon aerosols are released into the atmosphere, under the influence of complex meteorological environments, they undergo processes such as collision and fusion, hygroscopic growth, and photochemical aging. This results in significant changes in the composition, thickness, and mixed structure of the encapsulation layer, leading to complex variations in the optical properties of black carbon aerosols and consequently, diverse impacts on their radiation climate effects. Therefore, developing methods to invert the composition of black carbon aerosol encapsulation layers is of great significance for assessing their radiation climate effects.

[0003] Current aerosol composition inversion techniques are mostly applicable to all types of aerosols, without considering aerosol mixing patterns. In 2019, Ni Changjian et al. from Chengdu University of Information Technology proposed an inversion method for the hygroscopic growth factor in uniformly mixed aerosols, but this method did not consider the aerosol mixing structure. In 2022, Li Zhengqiang et al. from the Aerospace Information Research Institute of the Chinese Academy of Sciences proposed an atmospheric aerosol composition inversion method to obtain the hygroscopic growth of water-soluble components. While these methods can invert the water content of aerosols based on hygroscopic growth, they cannot invert compositional changes caused by photochemical aging, nor can they invert the composition of different components in black carbon aerosol coatings. Summary of the Invention

[0004] The purpose of this invention is to provide a method for inverting the composition of black carbon aerosol encapsulation layers with different particle sizes, so as to solve the problem that existing aerosol composition inversion methods cannot invert the composition of black carbon aerosol encapsulation layers.

[0005] The present invention is implemented as follows: an inversion method for the composition of black carbon aerosol coatings with different particle sizes, comprising the following steps.

[0006] Step 1: Assume that the encapsulated black carbon particles have a double-shell structure, and the encapsulation layer contains one or more of sulfates, non-absorbent organic matter, absorbent organic matter, and water, and the different encapsulation layer components are uniformly mixed.

[0007] Step 2: Sample the encapsulated black carbon aerosol and use a differential electromobility analyzer to screen out particles with a specific electromobility size D.m,p Encapsulated black carbon particles.

[0008] Step 3: Select the electromobility particle size D of the screened black carbon particles. m,p Converted to equal volume particle size D ve,p .

[0009] Step 4: Pass the selected encapsulated black carbon particles into an aerosol single-scattering albedo spectrometer to measure the scattering coefficient σ in multiple wavelength bands. sca,mea,λ Absorption coefficient σ abs,mea,λ and single-scatter albedo (SSA) mea,λ .

[0010] Step 5: Pass the coated black carbon particles that have passed through the single-scattering albedo spectrometer into the thermal erosion tube to remove the coating layer of the black carbon aerosol. Then, pass the particles through a scanning electromobility particle size spectrometer to measure the electromobility particle size D of the black carbon core. m,c .

[0011] Step 6: Determine the electromobility particle size D of the black carbon core. m,c Converted to equal volume particle size D ve,c .

[0012] Step 7: Assuming the complex refractive index of the coating layer is m = n + ki, and using a black carbon core with a uniform volumetric particle size D... ve,c The volumetric particle size D of the encapsulated black carbon particles is... ve,p And the value of complex refractive index, and the scattering coefficient σ in multiple bands is calculated based on the core-shell Mie scattering theory. sca,cal,λ Absorption coefficient σ abs,cal,λ and single-scatter albedo (SSA) cal,λ Establish a lookup table for the calculation results of optical properties.

[0013] Step 8: Construct the objective function F1, using the scattering coefficient σ measured under different wavebands. sca,mea,λ Absorption coefficient σ abs,mea,λ Single-scatter albedo (SSA) mea,λ Based on this, the optical property calculation result lookup table is retrieved, and the equivalent complex refractive index of the cladding layer that minimizes the objective function F1 is denoted as m. coating,λ =n coating,λ +k coating,λ i, the objective function F1 is as follows:

[0014]

[0015] Step 9: Calculate the complex refractive index of the coating layer after uniformly mixing different coating layer components according to different volume fractions based on multiple theories, and construct a lookup table for the complex refractive index calculation results.

[0016] Step 10: Construct the objective function F2, using the equivalent complex refractive index m of the cladding layer obtained in Step 8. coating =n coating +k coating Based on i, the complex refractive index calculation result lookup table is retrieved to obtain the volume fraction V corresponding to different encapsulation components that minimize the objective function F2. j,ret The objective function F2 is as follows:

[0017]

[0018] In the formula, m coating,λ n coating,λ and k coating,λ These represent the equivalent complex refractive index, real part, and imaginary part of the black carbon coating at different wavelengths, m cal,λ n cal,λ and k cal,λ These represent the complex refractive index, real part, and imaginary part of the black carbon coating, calculated according to different theories for different wavelength bands.

[0019] In steps 3 and 6, the electromobility particle size D of the encapsulated black carbon particles is... m,p Converted to equal volume particle size D ve,p Or black carbon nuclear power mobility particle size D m,c Converted to equal volume particle size D ve,c The formula is as follows:

[0020]

[0021]

[0022] Where χ is the dynamic shape factor, D m D represents the particle size for electromobility. ve For equal-volume particle sizes, C is the conversion factor between the two particle sizes, α, β, and γ are slip correction factors, and λ... gas Let be the mean free path of the gas molecules.

[0023] In step 9, the complex refractive index of the coating layer after uniformly mixing different coating layer components with different volume fractions is calculated based on the Maxwell-Garnett, Bruggeman and Volume-Average theories.

[0024] The dielectric constant ε of any two components homogeneously mixed according to Maxwell-Garnett theory MG The calculation formula is as follows:

[0025]

[0026] In the formula, ε1 and ε2 are the dielectric constants of different components, V1 represents the volume fraction of the component corresponding to ε1, and λ is the wavelength;

[0027] When the black carbon coating is formed by mixing multiple components, the dielectric constant of any two components is first calculated according to the above formula. Then, the two components are regarded as a new component and uniformly mixed with a third coating component. The new dielectric constant is then calculated according to the above formula. The dielectric constant of all coating components is calculated in this way.

[0028] The real part n(λ) and imaginary part k(λ) of the complex refractive index of the black carbon coating are calculated using the following formula:

[0029]

[0030]

[0031] In the formula, ε r (λ) and ε i (λ) represents the dielectric constant ε of the cladding layer. MG The real and imaginary parts.

[0032] The dielectric constant ε of black carbon coating based on Bruggeman theory B It can be calculated using the following formula:

[0033]

[0034] In the formula, ε j V represents the dielectric constant of different cladding layer compositions. j ε j Volume fraction of the corresponding component;

[0035] The real part n(λ) and imaginary part k(λ) of the complex refractive index of the black carbon coating are calculated using the following formula:

[0036]

[0037]

[0038] In the formula, ε r (λ) and ε i (λ) represents the dielectric constant ε of the cladding layer. B The real and imaginary parts of λ, where λ is the wavelength.

[0039] The real part n of the complex refractive index of black carbon coating based on Volume-Average theory VA (λ) and the imaginary part k VA (λ) can be calculated using the following formula:

[0040] n VA (λ)=∑V j n j (λ)

[0041] k VA (λ)=∑V j k j (λ)

[0042] In the formula, n j (λ) and k j (λ) represents the real and imaginary parts of the complex refractive index for different components, respectively, and λ is the wavelength.

[0043] The volume fraction of different coating layer components ranges from 0 to 1.0, with a step size of less than or equal to 0.01. Sulfate, non-absorbable organic matter, absorbable organic matter, and one or more of water can be selected as needed, and the total volume fraction of all components is 1.

[0044] The complex refractive indices of sulfate and water are taken as 1.50+0i and 1.33+0i, respectively; the complex refractive indices of non-absorbing organic compounds in the 532nm and 1064nm bands are 1.53+0.006i and 1.52+0.02i, respectively, and the complex refractive indices of absorbing organic compounds in the 532nm and 1064nm bands are 1.55+0.28i and 1.55+0.18i, respectively.

[0045] This invention assumes that the coating layer consists of one or more homogeneous mixtures of sulfate, non-absorbent organic matter, absorbent organic matter, and water. It retrieves the proportions of different components by minimizing the relative differences between the real and imaginary parts measured and calculated separately. This invention can sieve black carbon aerosols of different particle sizes and obtain the mixing ratios of different coating layer components through optical measurement and inversion. Attached Figure Description

[0046] Figure 1 This invention is an inversion device for the composition of black carbon aerosol coatings with different particle sizes.

[0047] Figure 2 This is a flowchart of the inversion method for the composition of black carbon aerosol coatings with different particle sizes according to the present invention.

[0048] Figure 3 The water volume fraction is the preset and inverted value in the embodiments of the present invention. Detailed Implementation

[0049] This invention is an inversion method for the composition of black carbon aerosol coatings with different particle sizes, such as... Figure 1 , Figure 2 As shown, the inversion method of the present invention specifically includes the following steps.

[0050] Step 1: Assume that the encapsulated black carbon particles have a double-shell structure, and the encapsulation layer contains one or more of sulfates, non-absorbent organic matter, absorbent organic matter (brown carbon), and water, and the different encapsulation layer components are uniformly mixed.

[0051] Step 2: Sample the encapsulated black carbon aerosol and use a differential electromobility analyzer (DMA) to screen for particles with a specific electromobility size D. m,p Encapsulated black carbon particles, such as 100, 200, 300 nm, etc.

[0052] Step 3: Select the electromobility particle size D of the screened black carbon particles. m,p Converted to equal volume particle size D ve,p .

[0053] The conversion formula is as follows:

[0054]

[0055]

[0056] Where χ is the dynamic shape factor, D m D represents the particle size for electromobility. ve For equal-volume particle sizes, C is the conversion factor between the two particle sizes, α, β, and γ are slip correction factors, and λ... gas Let be the mean free path of the gas molecules.

[0057] The slip correction factors α, β, and γ are taken as 1.142, 0.558, and 0.999, respectively, and the mean free path λ of the gas molecules is... gas Take 65 nm. For encapsulated black carbon particles, the dynamic shape factor χ p Take 2.2.

[0058] Step 4: Pass the encapsulated black carbon particles selected by DMA into an aerosol single-scattering albedo spectrometer to measure the scattering coefficient σ in multiple bands. sca,mea,λ Absorption coefficient σ abs,mea,λ and single-scatter albedo (SSA) mea,λ .

[0059] Step 5: Pass the coated black carbon particles that have passed through the single-scattering albedo spectrometer into the thermal ablation tube to remove the coating layer of the black carbon aerosol. Then, pass the particles through a scanning electromobility particle size spectrometer (SMPS) to measure the electromobility particle size D of the black carbon core. m,c .

[0060] Step 6: Determine the electromobility particle size D of the black carbon core. m,c Converted to equal volume particle size D ve,c .

[0061] The conversion formula is as follows:

[0062]

[0063]

[0064] Where χ is the dynamic shape factor, D m D represents the particle size for electromobility. ve For equal-volume particle sizes, C is the conversion factor between the two particle sizes, α, β, and γ are slip correction factors, and λ... gas Let be the mean free path of the gas molecules.

[0065] The slip correction factors α, β, and γ are taken as 1.142, 0.558, and 0.999, respectively, and the mean free path λ of the gas molecules is... gas Take 65 nm. For black carbon cores, the dynamic shape factor χ c Take 1.4.

[0066] Step 7: Assume the complex refractive index of the coating layer is m = n + ki, the real part m ranges from 1.1 to 1.9 with a step size less than or equal to 0.01, and the imaginary part n ranges from 0 to 1.0 with a step size less than or equal to 0.01; the complex refractive index of black carbon is taken as 2.26 + 1.26i; and the uniform volume particle size D of the black carbon core is adopted. ve,c The volumetric particle size D of the encapsulated black carbon particles is... ve,p And the value of complex refractive index, and the scattering coefficient σ in multiple bands is calculated based on the core-shell Mie scattering theory. sca,cal,λ Absorption coefficient σ abs,cal,λ and single-scatter albedo (SSA) cal,λ Establish a lookup table for the calculation results of optical properties.

[0067] Step 8: Construct the objective function F1, using the scattering coefficient σ measured under different wavebands. sca,mea,λ Absorption coefficient σ abs,mea,λ Single-scatter albedo (SSA) mea,λ Based on this, the optical property calculation result lookup table is retrieved, and the equivalent complex refractive index of the cladding layer that minimizes the objective function F1 is denoted as m. coating,λ =n coating,λ +k coating,λ i, the objective function F1 is as follows:

[0068]

[0069] Step 9: Calculate the complex refractive index of the coating layer after uniformly mixing different coating layer components according to different volume fractions based on multiple theories, and construct a lookup table for the complex refractive index calculation results.

[0070] The complex refractive index of the coating layer after uniformly mixing different coating layer components with different volume fractions was calculated based on the Maxwell-Garnett, Bruggeman, and Volume-Average theories.

[0071] The volume fraction of different coating layer components ranges from 0 to 1.0, with a step size of less than or equal to 0.01. Sulfate, non-absorbable organic matter, absorbable organic matter, and one or more of water can be selected as needed, and the total volume fraction of all components is 1.

[0072] The complex refractive indices of sulfate and water are taken as 1.50+0i and 1.33+0i, respectively; the complex refractive indices of non-absorbing organic compounds in the 532nm and 1064nm bands are 1.53+0.006i and 1.52+0.02i, respectively, and the complex refractive indices of absorbing organic compounds in the 532nm and 1064nm bands are 1.55+0.28i and 1.55+0.18i, respectively.

[0073] The following are methods for calculating the complex refractive index of the cladding layer based on different theories:

[0074] (a) The dielectric constant ε of any two components homogeneously mixed based on Maxwell-Garnett theory MG The calculation formula is as follows:

[0075]

[0076] In the formula, ε1 and ε2 are the dielectric constants of different components, V1 represents the volume fraction of the component corresponding to ε1, and λ is the wavelength;

[0077] When the black carbon coating is formed by mixing multiple components, the dielectric constant of any two components is first calculated according to the above formula. Then, the two components are treated as a new component and uniformly mixed with a third coating component. The new dielectric constant is then calculated according to the above formula. The dielectric constant of all coating components is calculated in this way.

[0078] The real part n(λ) and imaginary part k(λ) of the complex refractive index of the black carbon coating are calculated using the following formula:

[0079]

[0080]

[0081] In the formula, ε r (λ) and ε i (λ) represents the dielectric constant ε of the cladding layer. MG The real and imaginary parts.

[0082] (b) Dielectric constant ε of black carbon coating based on Bruggeman theory B It can be calculated using the following formula:

[0083]

[0084] In the formula, ε j V represents the dielectric constant of different cladding layer compositions. j ε j Volume fraction of the corresponding component;

[0085] The real part n(λ) and imaginary part k(λ) of the complex refractive index of the black carbon coating are calculated using the following formula:

[0086]

[0087]

[0088] In the formula, ε r (λ) and ε i (λ) represents the dielectric constant ε of the cladding layer. B The real and imaginary parts of λ, where λ is the wavelength.

[0089] (c) The real part n of the complex refractive index of black carbon coating based on Volume-Average theory VA (λ) and the imaginary part k VA (λ) can be calculated using the following formula:

[0090] n VA (λ)=∑V j n j (λ)

[0091] k VA (λ)=∑V j k j (λ)

[0092] In the formula, n j (λ) and k j (λ) represents the real and imaginary parts of the complex refractive index for different components, respectively, and λ is the wavelength.

[0093] Step 10: Construct the objective function F2, using the equivalent complex refractive index m of the cladding layer obtained in Step 8. coating =n coating +k coating Based on i, the complex refractive index calculation result lookup table is retrieved to obtain the volume fraction V corresponding to different encapsulation components that minimize the objective function F2. j,ret The objective function F2 is as follows:

[0094]

[0095] In the formula, m coating,λ n coating,λ and k coating,λ These represent the equivalent complex refractive index, real part, and imaginary part of the black carbon coating at different wavelengths, m cal,λ n cal,λ and k cal,λ These represent the complex refractive index, real part, and imaginary part of the black carbon coating, calculated according to different theories for different wavelength bands.

[0096] The final volume fraction V corresponding to each of the different encapsulation components was obtained. j,ret That is what I wanted.

[0097] The following will provide a more detailed description of the inversion method for the composition of black carbon aerosol coatings with different particle sizes provided by the present invention, with reference to a specific embodiment.

[0098] Example:

[0099] This embodiment follows a process of "morphological modeling, optical simulation calculation, complex refractive index and composition inversion" to verify the effectiveness of the method provided by this invention through numerical simulation.

[0100] A fractal condensate model was chosen to represent the exposed black carbon particles. Under the preset dry conditions, the sulfate content of the encapsulated black carbon particles was 0.10, 0.075, and 0.05% of the volume, respectively, and the relative humidity was 30%. The composition of the black carbon encapsulation layer after moisture absorption was mainly sulfate and water, with the water volume fraction ranging from 0.19 to 0.20%.

[0101] Encapsulated black carbon particles with an electromobility range of 0.32–1.47 μm were selected. The equal volume particle size of the encapsulated black carbon particles and the exposed black carbon core were calculated, and a fractal black carbon model was generated accordingly. The complex refractive indices of sulfate and water were taken as 1.50+0i and 1.33+0i, respectively. The scattering coefficient, absorption coefficient, and single-scattering albedo of the fractal black carbon model at the 1064 nm wavelength were calculated and used as the measurement results of the single-scattering albedo spectrometer.

[0102] Assuming the complex refractive index of the cladding layer is m = n + ki, the real part m ranges from 1.1 to 1.9, and the step size is set to 0.006 after preliminary experimental comparison. Since neither water nor sulfate has absorptive properties, the imaginary part n is not considered. The complex refractive index of black carbon is taken as 2.26 + 1.26i. The optical properties are calculated based on the core-shell Mie scattering theory and a lookup table is established.

[0103] The complex refractive index of the coating layer was obtained by inversion using the scattering coefficient, absorption coefficient, and single-scattering albedo of the fractal black carbon model as a reference. Assuming that the volume fractions of sulfate and water both range from 0 to 1.0 with a step size of 0.01 and the sum of the volume fractions of the two components is 1, a lookup table for the complex refractive index calculation results was constructed based on Bruggeman theory.

[0104] Using the equivalent complex refractive index of the inverted coating as a reference, the volume fractions of sulfate and water were further inverted to obtain the inversion results as follows: Figure 3 As shown, the inversion results are distributed on both sides of the preset value. Under dry conditions, the larger the volume fraction of sulfate in the encapsulated black carbon particles, the greater the difference between the volume fraction of water obtained from the inversion and the preset value. In this embodiment, the inversion error of the water volume fraction is the smallest, at 5.9%. The method of the present invention can accurately invert the proportion of the encapsulation layer components.

[0105] This invention assumes that the coating layer consists of one or more homogeneous mixtures of sulfate, non-absorbent organic matter, absorbent organic matter, and water. It retrieves the proportions of different components by minimizing the relative differences between the real and imaginary parts measured and calculated separately. This invention can sieve black carbon aerosols of different particle sizes and obtain the mixing ratios of different coating layer components through optical measurement and inversion.

Claims

1. A method for inverting the composition of black carbon aerosol coatings with different particle sizes, characterized in that, Includes the following steps: Step 1: Assume that the encapsulated black carbon particles have a double-shell structure, and the encapsulation layer contains one or more of sulfates, non-absorbent organic matter, absorbent organic matter, and water, and the different encapsulation layer components are uniformly mixed. Step 2: Sample the encapsulated black carbon aerosol and use a differential electromobility analyzer to screen out particles with a specific electromobility size D. m,p Encapsulated black carbon particles; Step 3: Select the electromobility particle size D of the screened black carbon particles. m,p Converted to equal volume particle size D ve,p ; Step 4: Pass the selected encapsulated black carbon particles into an aerosol single-scattering albedo spectrometer to measure the scattering coefficient σ in multiple wavelength bands. sca,mea,λ Absorption coefficient σ abs,mea,λ and single-scatter albedo (SSA) mea,λ ; Step 5: Pass the coated black carbon particles that have passed through the single-scattering albedo spectrometer into the thermal erosion tube to remove the coating layer of the black carbon aerosol. Then, pass the particles through a scanning electromobility particle size spectrometer to measure the electromobility particle size D of the black carbon core. m,c ; Step 6: Determine the electromobility particle size D of the black carbon core. m,c Converted to equal volume particle size D ve,c ; Step 7: Assuming the complex refractive index of the coating layer is m = n + ki, and using a black carbon core with a uniform volumetric particle size D... ve,c The volumetric particle size D of the encapsulated black carbon particles is... ve,p And the value of complex refractive index, and the scattering coefficient σ in multiple bands is calculated based on the core-shell Mie scattering theory. sca,cal,λ Absorption coefficient σ abs,cal,λ and single-scatter albedo (SSA) cal,λ Establish a lookup table for optical property calculation results; Step 8: Construct the objective function F1, using the scattering coefficient σ measured under different wavebands. sca,mea,λ Absorption coefficient σ abs,mea,λ Single-scatter albedo (SSA) mea,λ Based on this, the optical property calculation result lookup table is retrieved, and the equivalent complex refractive index of the cladding layer that minimizes the objective function F1 is denoted as m. coating,λ =n coating,λ +k coating,λ i, the objective function F1 is as follows: Step 9: Calculate the complex refractive index of the coating layer after uniformly mixing different coating layer components according to different volume fractions based on multiple theories, and construct a lookup table for the complex refractive index calculation results; Step 10: Construct the objective function F2, using the equivalent complex refractive index m of the cladding layer obtained in Step 8. coating,λ =n coating,λ +k coating,λ Based on i, the complex refractive index calculation result lookup table is retrieved to obtain the volume fraction V corresponding to different encapsulation components that minimize the objective function F2. j,ret The objective function F2 is as follows: In the formula, m coating,λ n coating,λ and k coating,λ These represent the equivalent complex refractive index, real part, and imaginary part of the black carbon coating at different wavelengths, m cal,λ n cal,λ and k cal,λ These represent the complex refractive index, real part, and imaginary part of the black carbon coating, calculated according to different theories for different wavelength bands.

2. The method for inverting the composition of black carbon aerosol coatings with different particle sizes according to claim 1, characterized in that, In steps 3 and 6, the electromobility particle size D of the encapsulated black carbon particles is... m,p Converted to equal volume particle size D ve,p Or black carbon nuclear power mobility particle size D m,c Converted to equal volume particle size D ve,c The formula is as follows: Where χ is the dynamic shape factor, D m D represents the particle size for electromobility. ve For equal-volume particle sizes, C is the conversion factor between the two particle sizes, α, β, and γ are slip correction factors, and λ... gas Let be the mean free path of the gas molecules.

3. The method for inverting the composition of black carbon aerosol coatings with different particle sizes according to claim 1, characterized in that, In step 9, the complex refractive index of the coating layer after uniformly mixing different coating layer components with different volume fractions is calculated based on the Maxwell-Garnett, Bruggeman and Volume-Average theories.

4. The method for inverting the composition of black carbon aerosol coatings with different particle sizes according to claim 3, characterized in that, The dielectric constant ε of any two components homogeneously mixed according to Maxwell-Garnett theory MG The calculation formula is as follows: In the formula, ε1 and ε2 are the dielectric constants of different components, V1 represents the volume fraction of the component corresponding to ε1, and λ is the wavelength; When the black carbon coating is formed by mixing multiple components, the dielectric constant of any two components is first calculated according to the above formula. Then, the two components are regarded as a new component and uniformly mixed with a third coating component. The new dielectric constant is then calculated according to the above formula. The dielectric constant of all coating components is calculated in this way. The real part n(λ) and imaginary part k(λ) of the complex refractive index of the black carbon coating are calculated using the following formula: In the formula, ε r (λ) and ε i (λ) represents the dielectric constant ε of the cladding layer. MG The real and imaginary parts.

5. The method for inverting the composition of black carbon aerosol coatings with different particle sizes according to claim 3, characterized in that, The dielectric constant ε of black carbon coating based on Bruggeman theory B It can be calculated using the following formula: In the formula, ε j V represents the dielectric constant of different coating layer compositions. j ε j Volume fraction of the corresponding component; The real part n(λ) and imaginary part k(λ) of the complex refractive index of the black carbon coating are calculated using the following formula: In the formula, ε r (λ) and ε i (λ) represents the dielectric constant ε of the cladding layer. B The real and imaginary parts of λ, where λ is the wavelength.

6. The method for inverting the composition of black carbon aerosol coatings with different particle sizes according to claim 3, characterized in that, The real part n of the complex refractive index of black carbon coating based on Volume-Average theory VA (λ) and the imaginary part k VA (λ) can be calculated using the following formula: n VA (λ)=∑V j n j (l) k VA (λ)=∑V j k j (l) In the formula, n j (λ) and k j (λ) represents the real and imaginary parts of the complex refractive index for different components, respectively, and λ is the wavelength.

7. The method for inverting the composition of black carbon aerosol coatings with different particle sizes according to claim 1, characterized in that, The volume fraction of different coating layer components ranges from 0 to 1.0, with a step size of less than or equal to 0.

01. Sulfate, non-absorbable organic matter, absorbable organic matter, and one or more of water can be selected as needed, and the total volume fraction of all components is 1.

8. The method for inverting the composition of black carbon aerosol coatings with different particle sizes according to claim 1, characterized in that, The complex refractive indices of sulfate and water are taken as 1.50+0i and 1.33+0i, respectively; the complex refractive indices of non-absorbing organic compounds in the 532nm and 1064nm bands are 1.53+0.006i and 1.52+0.02i, respectively, and the complex refractive indices of absorbing organic compounds in the 532nm and 1064nm bands are 1.55+0.28i and 1.55+0.18i, respectively.

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