Method, device, medium and computer equipment for calculating aerosol mass concentration

Abstract

The present invention provides a method, device, medium and computer equipment for calculating aerosol mass concentration. The method includes: after using an injection module to focus an aerosol sample into a particle beam, receiving a bimodal sizing signal generated by the injection particles in the particle beam reaching the first position of a sizing module; using a mass spectrometry module to analyze the injection particles to obtain mass spectrum data; based on the mass spectrum data, calculating the original source-parsed distribution of a single category of particles; using the bimodal sizing signal, quantitatively correcting the original source-parsed distribution to obtain the true source-parsed distribution of the single category of particles; and calculating the mass concentration of the single category of particles based on the true source-parsed distribution. This method calculates the true particle size distribution of the single category of particles in the aerosol sample by correcting the original source-parsed data of a certain type of particle within each particle size range, thereby obtaining the mass concentration of the particle matter.

Description

Technical Field

[0001] The present invention relates to the technical field of aerosol mass spectrometry analysis, and more specifically, to an aerosol mass concentration calculation method, device, medium and computer equipment. Background Art

[0002] Source apportionment refers to the use of various scientific methods and techniques to determine the sources of atmospheric pollutants (such as aerosols, particulate matter, and gaseous pollutants) and their relative contributions. The difference in particle size of particles of the same substance in aerosols is mainly due to various physical and chemical factors during their formation and evolution. Taking nitrate aerosol as an example, nitrogen oxides (NOx) from automobile exhaust are oxidized to form nitrate particles, which are generally small in size, mostly between 0.1 and 1 micron. Ammonia released during agricultural fertilization reacts with acidic substances in the atmosphere to form nitrate particles, which may be larger in size, mostly between 1 and 5 microns. Therefore, by analyzing the particle size distribution of particles of a certain substance in aerosols, it is possible to calculate the main source of the substance, which in turn provides an important basis for formulating corresponding control measures (such as motor vehicle restrictions, coal-fired power conversion, industrial emission control, etc.).

[0003] In summary, obtaining the true particle size distribution of various particles from aerosols is of great significance for the analysis of environmental pollution. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a method, device, medium and computer equipment for calculating aerosol mass concentration to overcome the defect of the existing technology that it is difficult to obtain the true particle size distribution from the aerosol.

[0005] The above technical objectives of the present invention are achieved through the following technical solutions: a method for calculating aerosol mass concentration, applied to a single-particle aerosol mass spectrometer source desorption device, the source desorption device comprising: a sampling module, a diameter measurement module, and a mass spectrometry module; the mass concentration calculation method specifically comprises:

[0006] After the aerosol sample is focused into a particle beam using the sampling module, a double-peak sizing signal generated when the sample particles in the particle beam arrive at a first position of the sizing module is received, wherein the double-peak sizing signal is generated when the sample particles arriving at the first position are irradiated by a first laser unit in the sizing module;

[0007] Analyzing the injected particles using the mass spectrometry module to obtain mass spectrometry data;

[0008] Based on the mass spectrometry data, the original source-attributed distribution of the single-category particles is calculated; and using the bimodal sizing signal, the original source-attributed distribution is quantitatively corrected to obtain the true source-attributed distribution of the single-category particles;

[0009] Based on the true source-apportioned distribution, the mass concentration of a single type of particles is calculated.

[0010] In one embodiment, the laser generated by the first laser unit is two parallel laser beams; the receiving of the double-peak sizing signal generated by the sampled particles in the particle beam arriving at the first position of the sizing module specifically includes: respectively receiving two first light signals generated by each of the sampled particles passing through the two parallel laser beams in sequence, and generating a double-peak sizing signal based on the time difference between the two first light signals.

[0011] In one embodiment, the original source-analyzed distribution of single-category particles is calculated based on the mass spectrometry data, specifically including: determining the particle type of each ionized sampled particle and the number of particles corresponding to each particle type based on the mass spectrometry data; determining the original source-analyzed distribution of each single-category particle based on the particle type of the sampled particles and the number of particles corresponding to each particle type in the mass spectrometry data; the original source-analyzed distribution is specifically the number of the single-category particles in each particle size range.

[0012] In one embodiment, the bimodal sizing signal is used to perform a quantitative correction on the original source-parsed distribution to obtain a true source-parsed distribution of single-category particles, specifically including: calculating the statistical efficiency in each particle size range based on the bimodal sizing signal and the mass spectrometry data; calculating the ratio of the target number of each particle type in each particle size segment of the original source-parsed distribution to the statistical efficiency corresponding to the particle size segment to obtain the true source-parsed distribution.

[0013] In one embodiment, the statistical efficiency in each particle size segment is calculated based on the bimodal sizing signal and the mass spectrometry data, specifically including: generating a bimodal particle size distribution corresponding to the injected particles based on the time difference between the bimodal sizing signals; generating a mass spectrometry particle size distribution based on the particle information in the mass spectrometry data and the bimodal sizing distribution; and calculating the statistical efficiency in each particle size segment based on the bimodal sizing distribution and the mass spectrometry particle size distribution.

[0014] In one embodiment, the use of the mass spectrometry module to analyze the injected particles to obtain mass spectrometry data specifically includes: calculating the flight speed of the injected particles based on the time difference between the two first light signals and the distance between the two parallel laser beams; calculating the ionization time when the injected particles reach the ionization position based on the flight speed of the injected particles; and emitting an ionization laser to ionize the injected particles to generate ions according to the ionization time, measuring the mass-to-charge ratio of the ions, and obtaining the mass spectrometry data of the injected particles.

[0015] In one embodiment, the mass concentration of a single type of particle is calculated based on the true source-analyzed distribution, specifically comprising: quantitatively analyzing the aerosol sample based on the true source-analyzed distribution to obtain the true mass concentration ρ corresponding to any substance in all particle size ranges. N_Mj , the true mass concentration ρ of all substances within any particle size range N_di And the total mass concentration ρ corresponding to all substances in all particle size ranges N .

[0016] An aerosol mass concentration calculation device, wherein the source analysis device specifically comprises:

[0017] An optical signal receiving module is configured to receive a double-peak sizing signal generated when the sampled particles in the particle beam reach the first position of the sizing module after the aerosol sample is focused into a particle beam by the sampling module, wherein the double-peak sizing signal is generated when the sampled particles in the particle beam reach the first position of the sizing module by irradiating the sampled particles that reach the first position;

[0018] Mass spectrometry analysis module: used to analyze the injected particles using the mass spectrometry module to obtain mass spectrometry data;

[0019] Source-attributed calculation and correction module: used to calculate the original source-attributed distribution of a single type of particles based on the mass spectrometry data, and to perform quantitative correction on the original source-attributed distribution using the bimodal caliper signal to obtain the true source-attributed distribution of the single type of particles;

[0020] Mass concentration calculation module: used to calculate the mass concentration of a single type of particles based on the true source analysis distribution.

[0021] A computer-readable storage medium stores a computer program, which implements the steps of the above method when executed by a processor.

[0022] A computer device includes a memory and a processor, wherein the memory stores a computer program and the processor implements the steps of the above method when executing the computer program.

[0023] In summary, the present invention has the following beneficial effects: this method measures the first kinetic particle size of the particulate matter to obtain the first particle size distribution of the particulate matter, and then measures the second kinetic particle size of the particulate matter to obtain the second particle size distribution of the particles, and unifies the two particle size distributions to the volume equivalent diameter scale, so as to obtain the particle size statistical efficiency of the source analysis device in different particle size ranges. By using the method of the present application, the original source analysis data of a certain particle matter can be corrected in each particle size range during the use of a high-precision single-particle aerosol mass spectrometer, and the true particle size distribution of a single category of particles in the aerosol sample can be calculated. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a flow chart of a method for calculating aerosol mass concentration according to the present invention;

[0025] Figure 2 This is a structural diagram of an aerosol mass concentration calculation device of the present invention;

[0026] Figure 3 is a diagram showing the internal structure of a computer device in an embodiment of the present invention;

[0027] Figure 4 Schematic diagram of the structure of a SOMS device for aerosol source analysis in an embodiment of the present invention;

[0028] Figure 5 Schematic diagram of the ratio of the bimodal sizing signal and mass spectrometry data within each particle size range of the present invention;

[0029] Figure 6 This is a schematic diagram of the present invention of correcting the original source parsed distribution to obtain the true source parsed distribution.

[0030] In the figure, 1. aerodynamic lens; 2. optical signal receiver; 3. first laser emitter; 4. convex lens; 5. concave reflector; 6. beam splitter; 7. mass spectrometry equipment; 8. ionization laser; 9. reflector; 10. optical signal receiving module; 11. mass spectrometry module; 12. source resolution calculation and correction module; 13. mass concentration calculation module. DETAILED DESCRIPTION

[0031] To make the objectives, features, and advantages of the present invention more readily apparent, the following detailed description of the present invention is provided with reference to the accompanying drawings. The accompanying drawings illustrate several embodiments of the present invention. However, the present invention may be implemented in many different forms and is not limited to the embodiments described herein.

[0032] In the present invention, unless otherwise expressly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be a communication between the two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances. The terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of such features.

[0033] In the present invention, unless otherwise expressly specified and limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature includes the first feature being directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature. The terms "vertical," "horizontal," "left," "right," "above," "below," and similar expressions are for illustrative purposes only and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting the present invention.

[0034] The present invention is described in detail below with reference to the accompanying drawings and examples. To facilitate understanding of the examples, the relevant technology will first be described. In the prior art, particle number concentration is primarily measured using optical particle counters. Among these, an aerodynamic particle sizer (APS) is an instrument used to measure the aerodynamic size distribution of particles. It is widely used in particle measurement. The APS focuses particles using an aerodynamic lens and accelerates the airflow through an accelerator nozzle, producing a particle beam with a specific flight velocity. Particles of different sizes in the airflow experience different accelerations due to inertia. After the particles exit the nozzle, they are scattered by two parallel laser beams within the detection area, generating light signals. These scattered signals are converted into electrical pulses by a photodetector, with each particle generating two separate signals. This provides the time of flight between the two laser beams. The time of flight is then correlated with particle size using a formula to determine the particle size distribution. However, the APS cannot measure the chemical composition of particles, let alone provide information on the chemical composition of individual particles. Therefore, it is not suitable for accurate particle source analysis.

[0035] A single-particle aerosol mass spectrometer (SPMS) can measure the size and analyze the chemical composition of individual particles, addressing the shortcomings of APS devices. Existing SPMSs use an aerodynamic lens to focus particles into a collimated beam. When particles leave the aerodynamic lens exit, a velocity distribution related to the particle size is generated. In the sizing area, two laser beams, separated by a certain distance, generate light scattered by the particles. A photomultiplier tube measures the time difference between the two scattered beams to determine the particle's flight velocity and, thus, its aerodynamic size. Simultaneously, the particle's velocity is used to precisely trigger the downstream ionization laser, ionizing the particle at the precise moment it reaches the ion source. This process determines the particle size and chemical composition of individual particles. Because the chemical composition of a particle is closely related to its source, the mass spectral signature of a single particle can be considered its fingerprint, enabling source analysis. After a period of sampling, such as half an hour, SPMS can obtain information on the particle size and chemical composition of tens of thousands of individual particles. By classifying these large quantities of particulate matter, the proportion of different types of particles can be determined, as well as their temporal changes. This information provides a crucial reference for understanding the evolution of particulate matter, how to control particulate pollution, and evaluating measures to address it. Therefore, SPMS plays a vital role in atmospheric particulate matter source apportionment.

[0036] Although the use of SPMS equipment can obtain the particle size distribution and chemical composition of particulate matter, and plays an important role in aerosol analysis, in actual use, due to certain differences in the transmission efficiency of the equipment for particles of different particle sizes, the source analysis distribution of single-category particles measured by the equipment is difficult to reflect the true distribution of aerosol particles. A Chinese invention patent (patent number ZL201910043196.5) discloses a real-time quantitative analysis method for single-particle aerosols. In this application, the measurement results of some foreign equipment such as semi-continuous atmospheric monitors and beta-ray continuous particle monitors are used as standard results. The concept of strike rate is introduced to correct the sum of the peak areas of each component obtained by the SPAMS instrument analysis, thereby improving the correlation between the corrected peak area and the mass concentration of the particle. The mass concentration of the particle can then be calculated through the peak area, thereby achieving quantitative analysis of aerosol particles in a certain particle size range.

[0037] However, the application still has the following defects: the single particle aerosol mass spectrometer used in the application is model: SPAMS 0515 (produced by Guangzhou Hexin Analytical Instrument Co., Ltd.), which uses two parallel lasers to measure the particle size in the focused particle beam. Due to the phenomenon of particles overtaking each other during the sizing process and the low measurement accuracy, the number of particles that can be ionized is extremely small, the particle loss is large, and the number of particles that can be ionized and the mass spectrum data can be obtained is extremely small. According to the appendix of the description of the application, Figure 2 a and instructions Figure 2 From the order of magnitude of the vertical coordinate in b, it can be seen that there is a gap of nearly 10 times between CPA (sum of peak areas after correction) and PA (sum of peak areas before correction), and there will be certain losses in the process from the aerosol passing through the aerodynamic lens into the sizing module to the completion of sizing. Therefore, the strike rate obtained by calculating the ratio of the number of particles that simultaneously obtain particle size and mass spectrum information to the number of all particles containing particle size information in this application cannot reflect the true number concentration of particulate matter in the atmosphere.

[0038] In addition, the application also uses the mass concentration measured by some foreign equipment as standard data, and correlates the number concentration after correction of the equipment with the mass concentration to prove the effectiveness of the strike rate calculation. This method has the following problems: first, the mass concentration of aerosol particles measured by instruments is affected by many factors, and it is difficult to judge whether the data measured by the equipment is accurate; second, the correlation between the peak area and mass concentration after the strike rate correction is still difficult to be called a strong correlation. For example, in the particle size range of PM2.5, the K after the strike efficiency correction is + , Ca + Mg 2+ 、Na +The correlation coefficients with the test results of the standard equipment were only 0.77, 0.78, 0.39, and 0.47.

[0039] Example 1

[0040] In order to solve the above problems, the present invention provides a method for calculating aerosol mass concentration based on the source analysis method of single particle aerosol mass spectrometer. Figure 1 As shown, it is applied to a single-particle aerosol mass spectrometer source desorption device, which includes: a sampling module, a diameter measurement module and a mass spectrometry module; the mass concentration calculation method specifically includes:

[0041] S1. After focusing the aerosol sample into a particle beam using the sampling module, receiving a double-peak sizing signal generated when the sample particles in the particle beam arrive at a first position of the sizing module, wherein the double-peak sizing signal is generated when the sample particles arriving at the first position are irradiated by a first laser unit in the sizing module;

[0042] S2. Analyzing the injected particles using the mass spectrometry module to obtain mass spectrometry data;

[0043] S3. Calculating the original source-attributed distribution of the single-class particles based on the mass spectrometry data; and performing quantitative correction on the original source-attributed distribution using the bimodal sizing signal to obtain the true source-attributed distribution of the single-class particles.

[0044] S4. Calculate the mass concentration of a single type of particles based on the true source analysis distribution.

[0045] In order to improve the success rate of diameter measurement, the mass concentration calculation method of this application is based on the following Figure 4 A single-particle mass spectrometry device is shown, and the single-particle aerosol mass spectrometry device includes an injection module, a sizing module and a mass spectrometry module. The injection module is used to focus the particles in the aerosol into a particle beam. In this embodiment, the injection module can use an aerodynamic lens or a nozzle; the sizing module is used to measure and count the particles in the particle beam, and the mass spectrometry module is used to perform mass spectrometry analysis on the particles in the particle beam to determine the type of particles. When the source analysis is finally performed, the particle size of each substance can be identified separately according to the mass spectrometry data, and then the distribution of the actual source of the substance can be determined.

[0046] In order to make the measured data closer to the real data, the data actually measured by the device needs to be calibrated. Before calibration, it is necessary to calculate the calibration parameters of the device based on the measurement principle of the device, and then calibrate the measurement results of the device.

[0047] In the prior art, the transmission efficiency of an aerodynamic lens in the process of transmitting aerosol particles of 0.1 to 10 μm can be as high as over 95%. Therefore, the aerosol particles transmitted to the sizing module through the aerodynamic lens can be approximately regarded as having the same size distribution characteristics as the particles in the atmosphere. In summary, the loss of particles in the process of the aerodynamic lens transmitting particles is not obvious. Traditional SPMS equipment uses two parallel laser beams for sizing, and the time when the particles reach the second laser beam is also used to calculate the trigger time of the ionization laser. That is, when the particles are successively irradiated by the two laser beams, two laser scattered light signals are generated. By calculating the time difference between the two signals, the flight speed of the sampled particles, the kinetic particle size of the particles, and the precise time when the particles fly to the ionization position can be inferred, so that the measured particles can be hit by the ionization laser and ionized at the ionization position, so that their mass-to-charge ratio can be measured in subsequent mass spectrometry analysis. The velocities of the particles output by the aerodynamic lens are different, and particles may overtake each other during the sizing process. The calculated velocity after passing through the two lasers differs from the actual particle velocity, and the ionization laser cannot accurately ionize the particles, affecting the final particle mass spectrum statistics and the correspondence between the mass spectrum data and the particles. To address the above problems, this application proposes a new method for calculating aerosol mass concentration. First, a bimodal sizing signal is used to perform a preliminary measurement of the number of particles and the diameter of the particles in the aerosol sample. Based on the above content, it can be seen that the counting result of the bimodal sizing signal can be approximately regarded as the number of particles in the aerosol sample. Although the particle size measured by the bimodal sizing signal has a low accuracy, it can still meet the statistical requirements of the particle size range. Because the particle size range is inherently a relatively wide range, although there is an error in the particle size measurement, as long as the error is much smaller than the particle size range, the particle size range statistical requirements can be met. Therefore, the particle size distribution of all particles in the aerosol sample can be obtained through the bimodal sizing signal. Then, based on the interval time of the double-peak sizing signal and the distance between the two lasers that generate the double-peak sizing signal, the particle's flight speed can be inferred, and the time when the particle enters the mass spectrometer can be determined. Then, at a specific time, an ionization laser is emitted to ionize the particles. When the particles are ionized, the mass-to-charge ratio of the particles is measured to obtain the type of particles. Since the data of the particles is bound to the particles, when the mass spectrometer data of the particles is obtained, the particle size distribution of the particles obtained by the mass spectrometer data can also be established. Without distinguishing the type of particles, the particle transmission efficiency of each particle size segment can be calculated based on the number of particles distributed in each particle size segment. Using the particle transmission efficiency of each particle size segment, based on the particle size distribution of single-category particles obtained by mass spectrometer data, the single-category particles are corrected using the transmission efficiency in each particle size segment, and the particle size distribution of single-category particles in the aerosol sample can be obtained, which is the true source-resolved distribution.Using the true source resolved distribution, combined with the average particle size of each size range and the average density of a single type of particle, the true mass concentration of the particulate matter can be calculated.

[0048] In summary, this application proposes a method for calculating the mass concentration of aerosol particles. By correcting the original source parsed distribution to obtain the true source parsed distribution, and then using the true source parsed distribution to determine the mass concentration of each type of particulate matter, the mass concentration of a single type of particulate matter can be obtained more accurately.

[0049] In one embodiment, the laser generated by the first laser unit is two parallel laser beams; the receiving of the double-peak sizing signal generated by the sampled particles in the particle beam arriving at the first position of the sizing module specifically includes: respectively receiving two first light signals generated by each of the sampled particles passing through the two parallel laser beams in sequence, and generating a double-peak sizing signal based on the time difference between the two first light signals.

[0050] The double-peak sizing signal is the scattered light signal generated after the sampled particles pass through two parallel lasers in sequence. It is reflected on the signal receiver as two peak-shaped signal points. The time interval between the two peak-shaped signal points is the time interval for the particles to pass through the two lasers. Then, based on the distance between the two lasers, the flight speed of the particles can be calculated. Since the flight speed of the particles corresponds to the kinetic diameter of the particles, the particle size distribution of the sampled particles in the aerosol sample can be obtained by counting the number of double-peak sizing signals and the time difference between the double-peak sizing signals. At this time, the particle size distribution does not distinguish between the types of particles. The particles are mixed with each other, so the particles can be regarded as uniformly mixed. In the subsequent ionization process, the particles that are not ionized can also be regarded as uniformly lost, so the category ratio of the particles can remain unchanged.

[0051] In one embodiment, the use of the mass spectrometry module to analyze the injected particles to obtain mass spectrometry data specifically includes: calculating the flight speed of the injected particles based on the time difference between the two first light signals and the distance between the two parallel laser beams; calculating the ionization time when the injected particles reach the ionization position based on the flight speed of the injected particles; and emitting an ionization laser to ionize the injected particles to generate ions according to the ionization time, measuring the mass-to-charge ratio of the ions, and obtaining the mass spectrometry data of the injected particles.

[0052] In practical applications, the mass spectrometry process requires the particles to be ionized first, such as Figure 4 As shown, particles enter the mass spectrometer, and the ionization laser in the mass spectrometer ionizes the particles that reach the ionization position to generate ions. After the ions fly in the mass spectrometer, they fall onto the receiving device to generate mass-to-charge ratio data.

[0053] In one embodiment, the original source-analyzed distribution of single-category particles is calculated based on the mass spectrometry data, specifically including: determining the particle type of each ionized sampled particle and the number of particles corresponding to each particle type based on the mass spectrometry data; determining the original source-analyzed distribution of each single-category particle based on the particle type of the sampled particles and the number of particles corresponding to each particle type in the mass spectrometry data; the original source-analyzed distribution is specifically the number of the single-category particles in each particle size range.

[0054] During the mass spectrometry data acquisition process, the mass-to-charge ratio of each particle is matched one-to-one with the double-peak signal obtained by the parallel laser. Therefore, after acquiring the mass spectrometry information of the particles, the particle size data can also be traced back, that is, the type and size of each particle can be determined. First, the sampled particles are classified according to their type, and then the size distribution of each type of particle is analyzed to obtain the original source-attributed distribution of each type of particle.

[0055] In one embodiment, the bimodal sizing signal is used to perform a quantitative correction on the original source-parsed distribution to obtain a true source-parsed distribution of single-category particles, specifically including: calculating the statistical efficiency in each particle size range based on the bimodal sizing signal and the mass spectrometry data; calculating the ratio of the target number of each particle type in each particle size segment of the original source-parsed distribution to the statistical efficiency corresponding to the particle size segment to obtain the true source-parsed distribution.

[0056] In practical applications, since the injected particles do not distinguish between the types of particles and the particles are mixed with each other, the particles can be regarded as uniformly mixed. In the subsequent ionization process, the particles that are not ionized can also be regarded as uniformly lost. Therefore, the category ratio of the particles can remain unchanged. Then, based on the overall statistical efficiency, the original source-attributed distribution of single-category particles can be corrected separately to obtain the true source-attributed distribution.

[0057] In one embodiment, the statistical efficiency in each particle size segment is calculated based on the bimodal sizing signal and the mass spectrometry data, specifically including: generating a bimodal particle size distribution corresponding to the injected particles based on the time difference between the bimodal sizing signals; generating a mass spectrometry particle size distribution based on the particle information in the mass spectrometry data and the bimodal sizing distribution; and calculating the statistical efficiency in each particle size segment based on the bimodal sizing distribution and the mass spectrometry particle size distribution.

[0058] In one embodiment, the mass concentration of a single type of particle is calculated based on the true source-analyzed distribution, specifically comprising: quantitatively analyzing the aerosol sample based on the true source-analyzed distribution to obtain the true mass concentration ρ corresponding to any substance in all particle size ranges. N_Mj , the true mass concentration ρ of all substances within any particle size range N_di And the total mass concentration ρ corresponding to all substances in all particle size ranges N .

[0059] Specifically, calculate the true mass concentration ρ corresponding to any substance in all particle size ranges N_Mj ,include:

[0060]

[0061] Among them, N i represents the total number of particles in the mass spectrometry data within the i-th particle size range; a i,j represents the proportion of the jth substance in the i-th particle size range; Q represents the injection flow rate of the instrument, in L / min; η i represents the statistical efficiency within the i-th particle size range; d i It represents the average particle size within the i-th particle size range.

[0062] Specifically, calculate the true mass concentration ρ of all substances within any particle size range N_di ,include:

[0063]

[0064] Among them, N i represents the total number of particles in the mass spectrum data within the i-th particle size range; d i represents the average particle size within the i-th particle size range; a i,j represents the proportion of the jth substance in the i-th particle size range; ρ j Indicates the density of the jth substance in g / m 3 ; Q represents the sample flow rate of the instrument, in L / min; η i It represents the statistical efficiency within the i-th particle size range.

[0065] Specifically, calculate the total mass concentration ρ of all substances within all particle size ranges N ,include:

[0066]

[0067] Among them, N irepresents the total number of particles in the mass spectrum data within the i-th particle size range; d i represents the average particle size within the i-th particle size range; a i,j represents the proportion of the jth substance in the i-th particle size range; ρ j Indicates the density of the jth substance in g / m 3 ; Q represents the sample flow rate of the instrument, in L / min; η i It represents the statistical efficiency within the i-th particle size range.

[0068] In summary, this application proposes a method for calculating aerosol mass concentration. By calculating the statistical efficiency of the sampled particles in each particle size segment, the number of single-category particles in each particle size segment is corrected, and then the actual number of single-category particles in each particle size segment is obtained, and the true source-resolved distribution of single-category particles is obtained, and finally the true mass concentration of the target particles can be calculated.

[0069] Example 2

[0070] Applied to a single-particle aerosol mass spectrometry device, the single-particle aerosol mass spectrometry device includes: an injection module, a diameter measurement module and a mass spectrometry module; the mass concentration calculation method specifically includes:

[0071] S1. After focusing the aerosol sample into a particle beam using the sampling module, receiving a double-peak sizing signal generated by sample particles in the particle beam arriving at a first position of the sizing module, and a second sizing signal generated by particles to be analyzed in the particle beam arriving at a second position of the sizing module; wherein the double-peak sizing signal is generated by the first laser unit in the sizing module irradiating particles arriving at the first position, and the second sizing signal is generated by the second laser unit in the sizing module irradiating particles arriving at the second position;

[0072] S2. emitting an ionization laser based on the second diameter measurement signal to ionize the particles to be analyzed into ions, and analyzing the ions using the mass spectrometry module to obtain mass spectrum data of the ions;

[0073] S3. Calculating an original source-attributed distribution of a single type of particles based on the mass spectrometry data, and quantitatively correcting the original source-attributed distribution using the bimodal sizing signal and the second sizing signal to obtain a true source-attributed distribution of the single type of particles;

[0074] S4. Calculate the mass concentration of a single type of particles based on the true source analysis distribution.

[0075] Specifically, compared to Example 1, this embodiment incorporates an additional second laser unit. This second laser unit is used to further identify particle size based on the bimodal sizing signal. Specifically, the bimodal sizing signal is used to perform a preliminary measurement of the number and diameter of particles in the aerosol sample. Based on the previous discussion, the bimodal sizing signal count can be roughly interpreted as the number of particles in the aerosol sample. While the particle size measured by the bimodal sizing signal has lower accuracy, it can still meet the statistical requirements for particle size ranges. This is because the particle size range is inherently broad. While there may be errors in particle size measurement, as long as the errors are significantly smaller than the particle size range, the requirements for particle size range statistics can be met. Therefore, the bimodal sizing signal can be used to obtain the size distribution of all particles in the aerosol sample. The particles are then controlled to arrive at a second location, where they are illuminated by a second sizing laser beam, generating a second sizing signal. The purpose of providing this second sizing signal in this application is to determine the specific moment at which the particles reach the ionization location by measuring their time of flight, thereby facilitating accurate ionization of the particles. In addition, the use of the bimodal sizing signal and the second sizing signal can further accurately measure the diameter of the particles. Please refer to the subsequent content for the specific calculation process. After laser ionization, the particles finally enter the mass spectrometry module to measure the properties of the particles to determine the type of particles and count the number of each particle. Through the above steps, the true source parsed distribution of the particles corresponding to each substance in the aerosol sample can be determined. Using the true source parsed distribution, combined with the average particle size of each particle size range and the average density of a single type of particles, the true mass concentration of the particles can be calculated.

[0076] To ensure that the detection results more closely match the particle size distribution of the input aerosol, the present application incorporates a first laser unit and a second laser unit in the sizing module. The first laser unit emits two parallel laser beams, closely spaced. Therefore, when a particle passes through the area illuminated by the first laser unit, a double-peaked sizing signal is generated. Since the time interval between the two parallel laser beams is known, the particle's first velocity can be calculated by dividing the laser interval by the flight time. Due to the small spacing between the laser beams emitted by the first laser unit, the resulting first velocity is not an exact velocity but rather an estimate used to predict the time it will take for the particle to reach the location of the laser beam from the second laser unit. Furthermore, because the spacing between the two laser beams emitted by the first laser unit is extremely small, the likelihood of multiple particles occurring within this spacing is extremely low. As can be seen, when multiple particles traverse the laser beams within a predetermined timeframe, multiple light signals are generated. In this case, it is impossible to distinguish which two light signals are generated by the same particle traversing the two laser beams, making it impossible to calculate velocity. Therefore, when more than two optical signals appear, it can be assumed that more than two particles passed through the two parallel laser beams within a preset time range. It is impossible to distinguish which particle these optical signals belong to, so the particle corresponding to this optical signal must be excluded. When a double-peaked diameter measurement signal is obtained, the first velocity is further accurately calculated to obtain the estimated time and estimated range of the particle's arrival at the second laser position. The distance between the first and second laser units is also known, so the time it takes for the particle to reach the laser beam emitted by the second laser unit can be calculated based on the first velocity. However, due to the low accuracy of the first velocity, the resulting time will not be highly accurate. In some cases, two particles are sufficiently far apart that only two signals are generated within the preset time range when they pass through the first laser unit, resulting in the first laser unit identifying two valid signals. However, the distance between the two particles is smaller than the distance between the first and second laser units. Therefore, when the two particles pass through the laser beam emitted by the second laser unit, the identity of the generated optical signals is unknown, making it impossible to accurately calculate the velocity of each particle. Therefore, it is necessary to calculate an estimated time and time range for each particle that generates a valid signal to distinguish particles in this situation. By using the above-mentioned velocity calculation method, particles passing through the two laser units can be distinguished as much as possible, thereby reducing the number of particles whose velocity cannot be measured.

[0077] In one embodiment, the original source-analyzed distribution of single-category particles is calculated based on the mass spectrometry data, specifically including: determining the particle type of each ionized sampled particle and the number of particles corresponding to each particle type based on the mass spectrometry data; determining the original source-analyzed distribution of each single-category particle based on the particle type of the sampled particles and the number of particles corresponding to each particle type in the mass spectrometry data; the original source-analyzed distribution is specifically the number of the single-category particles in each particle size range.

[0078] In practical applications, when acquiring mass spectrometry data, the mass-to-charge ratio of each particle is consistently correlated with the double-peak signal obtained by the parallel laser. Therefore, after acquiring the mass spectrometry information, the particle size data can also be traced back, that is, the type and size of each particle can be determined. By first classifying the sampled particles based on their type, and then analyzing the size distribution of each particle type, the original source-attributed distribution of each particle type can be obtained.

[0079] In one embodiment, the bimodal sizing signal and the second sizing signal are used to perform a quantitative correction on the original source-parsed distribution to obtain a true source-parsed distribution of single-category particles, specifically including: calculating the statistical efficiency in each particle size range based on the bimodal sizing signal, the second sizing signal and the mass spectrometry data; calculating the ratio of the target number of each particle type in each particle size segment of the original source-parsed distribution to the statistical efficiency corresponding to the particle size segment to obtain a true source-parsed distribution.

[0080] In one embodiment, the statistical efficiency in each particle size segment is calculated based on the bimodal sizing signal, the second sizing signal and the mass spectrum data, specifically including: generating a first sizing distribution corresponding to the injected particles based on the time difference between the bimodal sizing signals and the time difference between the second sizing signal and the bimodal sizing signal; generating a mass spectrum particle size distribution corresponding to the particles to be detected based on the number of particles in the mass spectrum data; and calculating the statistical efficiency in each particle size segment based on the first sizing distribution and the mass spectrum particle size distribution.

[0081] In practical applications, since the transmission efficiency of the equipment in each particle size segment is different, when calculating the statistical efficiency, it is necessary to calculate the statistical efficiency separately according to the pre-divided particle size segment range. Then, based on the statistical efficiency corresponding to each particle size segment, the particle size segment range of the original source analysis distribution is corrected separately. In this application, the transmission speed of the particles is only related to the diameter of the particles, and has nothing to do with the type of particles and the density of the particles. Therefore, in this application, the particles of all substances are regarded as a uniformly mixed whole, and only the statistical efficiency of each particle size range of the whole is analyzed. The statistical efficiency can be regarded as the statistical efficiency of each particle size of a certain substance.

[0082] In one embodiment, the first sizing distribution corresponding to the injected particles is generated based on the time difference between the bimodal sizing signals and the time difference between the second sizing signal and the bimodal sizing signal, specifically including: calculating the first flight velocity of each injected particle based on the time difference between the bimodal sizing signals and the distance between the two parallel laser beams emitted by the first laser unit; calculating the second flight velocity of each injected particle using the time difference between the bimodal sizing signal and the second sizing signal, and the distance between the laser beam emitted by the first laser unit and the laser beam emitted by the second laser unit; calculating the first volume equivalent diameter of the injected particles based on the first flight velocity and the second flight velocity of each injected particle, counting the number of injected particles in each particle size range, and generating a first particle size distribution.

[0083] In practical applications, when particles are initially input into the sizing module, all particles are counted. Simply counting the number of double-peak sizing signals yields the particle count. However, to determine the particle size distribution, not only the total number of particles but also their diameter is necessary. Using three parallel laser beams, the particle velocity can be accurately measured, allowing the volume-equivalent diameter to be precisely calculated. This precisely calculated particle diameter is then used to determine the primary particle size distribution.

[0084] In this application, most of the particles in the aerosol are between 0.1μm and 10μm. Therefore, in order to accurately capture the light signal scattered by the irradiated particles, the laser emitting laser in this application is a continuous laser with a wavelength range of 300-1500nm. The shorter the wavelength, the better the detection performance for small-diameter particles.

[0085] The first laser unit emits two parallel lasers, which can be achieved by using a beam splitter 6. The beam splitter 6 can split the light into two parallel laser beams with a certain distance according to the polarization state of the light. The distance between the two laser beams is related to the thickness and crystal orientation of the crystal. The optical crystal material can be quartz, calcite, yttrium vanadate, etc. Its principle is to utilize the different refractive indices of light with different polarization properties in the birefringent crystal. Therefore, the beam splitter 6 can generate two parallel polarization states with a certain offset and orthogonal light beams. In the present application, the distance between the two laser beams generated by the refraction of the beam splitter is about 300μm.

[0086] In one embodiment, the original source-analyzed distribution of single-category particles is calculated based on the mass spectrometry data, specifically including: determining the particle type of each ionized sampled particle and the number of particles corresponding to each particle type based on the mass spectrometry data; determining the original source-analyzed distribution of each single-category particle based on the particle type of the sampled particles and the number of particles corresponding to each particle type in the mass spectrometry data; the original source-analyzed distribution is specifically the number of the single-category particles in each particle size range.

[0087] In the process of acquiring mass spectrometry data, the mass-to-charge ratio data of each particle can correspond one-to-one to the double-peak signal obtained by the parallel laser. Therefore, after obtaining the mass spectrometry information of the particle, the particle size data of the particle can also be traced back, that is, the type and particle size of each particle can be obtained. Then, the sampled particles are first classified based on the type of particle, and then the particle size distribution of each category of particles is analyzed to obtain the original source analysis distribution of a single category of particles. In one embodiment, the statistical efficiency within each particle size range is calculated based on the first diameter measurement distribution and the mass spectrum particle size distribution, specifically including:

[0088] Convert the kinetic particle size of each particle into a volume equivalent diameter;

[0089] Recalculating the first diameter distribution based on the volume equivalent diameter of each particle;

[0090] Recalculate the mass spectrometry particle size distribution based on the volume equivalent diameter of each particle;

[0091] The ratio of the number of each particle size segment in the first size distribution to the number of each particle size segment in the mass spectrum particle size distribution is used as the statistical efficiency of each particle size segment.

[0092] In practical applications, the specific principle of measuring the flight time of particles based on the first laser unit and the second laser unit and then calculating the kinetic particle size of the particles has been explained in detail above and will not be repeated here. Based on the kinetic particle size of the particles and the number of particles, the particle size distribution based on the kinetic particle size can be obtained. The laser distance between the first laser and the second laser is relatively far, so the particle overtaking phenomenon between the lasers is more serious. Since there is a large loss of particles in the kinetic particle size algorithm, the statistical efficiency of particles in each particle size segment can be calculated based on the first sizing distribution and the mass spectrometry particle size distribution. In addition, the accuracy of particle size measurement can be further improved based on the bimodal sizing signal and the second sizing signal.

[0093] In this application, the particle size of the particles is based on the statistics of the dynamic particle size, so the particle size needs to be unified to the physical particle size before comparison. The aerodynamic diameter is defined as the diameter of a sphere with a unit density (1g / cm3) that has the same terminal sedimentation rate as the object of study. Therefore, the particles have the same dynamic performance as the sphere with a unit density under this diameter. In the active sampling method, the particle size is characterized by the aerodynamic diameter. Aerodynamic diameter d a The conversion to geometric diameter d is calculated using the following formula:

[0094] d=kd a

[0095] Where k is the conversion factor.

[0096] In this application, if Figure 5 As shown in Figure 2, since particles can be considered uniformly mixed during transport, the loss of each type of particle, if distributed within this size range, also conforms to the law of statistical efficiency. Therefore, once the original source-attributed distribution of a substance is obtained, the true source-attributed distribution of that substance in the aerosol can be obtained by correcting it using statistical efficiency.

[0097] In one embodiment, the counting of the corresponding number of the single-category particles in each particle size segment to generate the original source parsed distribution of the single-category particles also includes: using the ART-2A model to cluster the particle size segments of the single-category particles to generate the original source parsed distribution of the single-category particles.

[0098] Specifically, source apportionment distribution is the analysis of the source of a single category of particles based on their size. Since the size changes of single-category particles are usually continuous, and the source of single-category particles is also affected by various factors, it is difficult to accurately classify particles under the influence of multiple factors using manual means. The ART-2A model can well perceive the inherent correlation of particles and cluster particles from different sources together. After clustering is completed, the particle sizes after clustering are corrected according to statistical efficiency to obtain the true source of aerosol particles.

[0099] In one embodiment, the mass concentration of a single type of particle is calculated based on the true source-analyzed distribution, specifically comprising: quantitatively analyzing the aerosol sample based on the true source-analyzed distribution to obtain the true mass concentration ρ corresponding to any substance in all particle size ranges. N_Mj , the true mass concentration ρ of all substances within any particle size range N_di And the total mass concentration ρ corresponding to all substances in all particle size ranges N For details on how to calculate the mass concentration, please refer to Example 1 and Example 6.

[0100] Example 3

[0101] See also Figure 2 , an aerosol mass concentration calculation device, the source analysis device specifically comprising:

[0102] The optical signal receiving module 10 is configured to receive a double-peak sizing signal generated when the sampled particles in the particle beam reach the first position of the sizing module after the aerosol sample is focused into a particle beam by the sampling module, wherein the double-peak sizing signal is generated when the sampled particles in the particle beam reach the first position of the sizing module by irradiating the sampled particles that reach the first position.

[0103] Mass spectrometry analysis module 11: configured to analyze the sampled particles using the mass spectrometry module to obtain mass spectrometry data;

[0104] Source-attributed calculation and correction module 12: used to calculate the original source-attributed distribution of a single type of particles based on the mass spectrometry data; and to perform quantitative correction on the original source-attributed distribution using the bimodal caliper signal to obtain the true source-attributed distribution of the single type of particles;

[0105] The mass concentration calculation module 13 is used to calculate the mass concentration of a single type of particles based on the true source analysis distribution.

[0106] The specific definition of an aerosol mass concentration calculation device can be found in the definition of an aerosol mass concentration calculation method described above and will not be repeated here. Each module in the aforementioned aerosol mass concentration calculation device can be implemented in whole or in part through software, hardware, or a combination thereof. Each of these modules can be embedded in or independent of a processor in a computer device in hardware form, or stored in a computer device memory in software form, so that the processor can call and execute the corresponding operations of each module.

[0107] Furthermore, the present application also provides a conversion formula for converting volume equivalent diameter to aerodynamic diameter, including:

[0108]

[0109] d ve : volume equivalent diameter; d a : aerodynamic diameter; χ: dynamic shape factor (taken as 1.4 in ambient air); ρ p : The true density of the particle; ρ0 reference density (usually 1 g / cm 3 ).

[0110] Those skilled in the art will understand that Figure 2 The structure shown in the figure is only a block diagram of a part of the structure related to the scheme of the present application and does not constitute a limitation of the scheme of the present application. A specific aerosol mass concentration calculation device may include more or fewer components than those shown in the figure, or combine certain components, or have a different component arrangement.

[0111] Example 4

[0112] A computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, an aerosol mass concentration calculation method as described in Example 1 is implemented.

[0113] Example 5

[0114] In one embodiment, a specific implementation method based on the above mass concentration calculation method is also provided.

[0115] An aerosol sample was obtained and passed through the SPMS device for analysis for one minute. The spectrum was obtained by the time-of-flight mass spectrometer and compared with the database. The composition of the particulate matter was found to be silicate, organic carbon, rust, polycyclic aromatic hydrocarbons, biomass, and the number concentration ratio of each substance. The density of the above substances was then found to be 2400 kg / m 3 , 800kg / m 3 , 1200kg / m 3 , 5000kg / m 3、1180kg / m 3 . Aerodynamic diameter d a The conversion coefficient k to geometric diameter d is 0.6, and the instrument injection flow rate is 0.6 L / min. The specific data are shown in the following table.

[0116]

[0117]

[0118] Among them, in this application, the average diameter refers to the average diameter of a certain particle size range, which is obtained by taking the average of the maximum and minimum values ​​within the particle size range; the sizing efficiency is calculated using the method in Example 1 or Example 2; the silicate content ratio refers to the content ratio of silicate in the particle size range. For example, if you want to perform source analysis on silicate particles, the silicate particles are the single-category particles referred to in Example 1. Taking the data in the first row as an example, in the particle size range of 0.15μm to 0.25μm, the silicate content ratio is 0.212, that is, in the particle size range of 0.15μm to 0.25μm, the number of sizing particles of the second kinetic particle size of silicate is 0.212*6914≈1466. In this embodiment, regardless of whether the statistical efficiency is calculated by the method of Example 1 or Example 2, the subsequent calculation method is the same, and the number of particles of the first kinetic particle size measured by silicate should be 1466 / 0.51=2874. In this particle size segment, the number concentration N of silicate should be In this application, the particles are approximately regarded as spheres, and the mass concentration of silicates can be calculated based on the number concentration and density of silicates. Where d is the average diameter of the particle size range, 0.2 μm, and the density of silicate is ρ = 2.4*10 6 g / m 3 , it can be deduced that the mass concentration of silicate in this particle size range is

[0119] Through the above steps, it can be seen that the true number concentration of silicate particles in each particle size segment can be calculated using statistical efficiency. Based on this method, the mass concentration of silicate in each particle size range can be further calculated.

[0120] Example 6

[0121] Furthermore, in addition to the calculation process for calculating mass concentration provided in Example 1, this application also provides other quantitative calculation processes, specifically including the true number concentration and the true content, specifically including:

[0122] Calculate the true number concentration C corresponding to any substance in all particle size rangest_Mi ,include:

[0123]

[0124] Among them, N i represents the total number of particles in the mass spectrometry data within the i-th particle size range; a i,j represents the proportion of the jth substance in the i-th particle size range; Q represents the injection flow rate of the instrument, in L / min; η i It represents the statistical efficiency within the i-th particle size range.

[0125] Calculate the true content of each substance α T_Mj ,include:

[0126]

[0127] Among them, a i,j Indicates the proportion of the jth substance in the i-th particle size range; N i represents the total number of particles in the mass spectrum data within the i-th particle size range; η i It represents the statistical efficiency within the i-th particle size range.

[0128] Example 7

[0129] In one embodiment, a computer device is provided. The computer device may be a server, and its internal structure diagram may be as follows: Figure 3 As shown. The computer device includes a processor, memory, a network interface, and a database connected via a system bus. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the operation of the operating system and computer program in the non-volatile storage medium. When executed by the processor, the computer program implements an aerosol mass concentration calculation method.

[0130] Those skilled in the art will understand that Figure 3 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than shown in the figure, or combine certain components, or have a different component arrangement.

[0131] In one embodiment, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and when the processor executes the computer program, the following steps are implemented:

[0132] After the aerosol sample is focused into a particle beam using the sampling module, a double-peak sizing signal generated when the sample particles in the particle beam arrive at a first position of the sizing module is received, wherein the double-peak sizing signal is generated when the sample particles arriving at the first position are irradiated by a first laser unit in the sizing module;

[0133] Analyzing the injected particles using the mass spectrometry module to obtain mass spectrometry data;

[0134] Based on the mass spectrometry data, the original source-attributed distribution of the single-category particles is calculated; and using the bimodal sizing signal, the original source-attributed distribution is quantitatively corrected to obtain the true source-attributed distribution of the single-category particles;

[0135] Based on the true source-apportioned distribution, the mass concentration of a single type of particles is calculated.

[0136] In one embodiment, the laser generated by the first laser unit is two parallel laser beams; the receiving of the double-peak sizing signal generated by the sampled particles in the particle beam arriving at the first position of the sizing module specifically includes: respectively receiving two first light signals generated by each of the sampled particles passing through the two parallel laser beams in sequence, and generating a double-peak sizing signal based on the time difference between the two first light signals.

[0137] In one embodiment, the original source-analyzed distribution of single-category particles is calculated based on the mass spectrometry data, specifically including: determining the particle type of each ionized sampled particle and the number of particles corresponding to each particle type based on the mass spectrometry data; determining the original source-analyzed distribution of each single-category particle based on the particle type of the sampled particles and the number of particles corresponding to each particle type in the mass spectrometry data; the original source-analyzed distribution is specifically the number of the single-category particles in each particle size range.

[0138] In one embodiment, the bimodal sizing signal is used to perform a quantitative correction on the original source-parsed distribution to obtain a true source-parsed distribution of single-category particles, specifically including: calculating the statistical efficiency in each particle size range based on the bimodal sizing signal and the mass spectrometry data; calculating the ratio of the target number of each particle type in each particle size segment of the original source-parsed distribution to the statistical efficiency corresponding to the particle size segment to obtain the true source-parsed distribution.

[0139] In one embodiment, the statistical efficiency in each particle size segment is calculated based on the bimodal sizing signal and the mass spectrometry data, specifically including: generating a bimodal particle size distribution corresponding to the injected particles based on the time difference between the bimodal sizing signals; generating a mass spectrometry particle size distribution based on the particle information in the mass spectrometry data and the bimodal sizing distribution; and calculating the statistical efficiency in each particle size segment based on the bimodal sizing distribution and the mass spectrometry particle size distribution.

[0140] In one embodiment, the use of the mass spectrometry module to analyze the injected particles to obtain mass spectrometry data specifically includes: calculating the flight speed of the injected particles based on the time difference between the two first light signals and the distance between the two parallel laser beams; calculating the ionization time when the injected particles reach the ionization position based on the flight speed of the injected particles; and emitting an ionization laser to ionize the injected particles to generate ions according to the ionization time, measuring the mass-to-charge ratio of the ions, and obtaining the mass spectrometry data of the injected particles.

[0141] In one embodiment, the mass concentration of a single type of particle is calculated based on the true source-analyzed distribution, specifically comprising: quantitatively analyzing the aerosol sample based on the true source-analyzed distribution to obtain the true mass concentration ρ corresponding to any substance in all particle size ranges. N_Mj , the true mass concentration ρ of all substances within any particle size range N_di And the total mass concentration ρ corresponding to all substances in all particle size ranges N .

[0142] Those skilled in the art will appreciate that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0143] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0144] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiment. All technical solutions based on the concept of the present invention are within the scope of protection of the present invention. It should be noted that for those skilled in the art, various improvements and modifications that do not depart from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A method for calculating aerosol mass concentration, characterized in that: Applied to a single-particle aerosol mass spectrometer source desorption device, the single-particle aerosol mass spectrometer source desorption device includes: an injection module, a diameter measurement module and a mass spectrometer module; the mass concentration calculation method specifically includes: After the aerosol sample is focused into a particle beam using the sampling module, a double-peak sizing signal generated by the sampled particles in the particle beam arriving at the first position of the sizing module is received, wherein the double-peak sizing signal is generated by the first laser unit in the sizing module irradiating the sampled particles arriving at the first position; the laser generated by the first laser unit is two parallel laser beams; the receiving of the double-peak sizing signal generated by the sampled particles in the particle beam arriving at the first position of the sizing module specifically comprises: respectively receiving two first light signals generated by each of the sampled particles sequentially passing through the two parallel laser beams, and generating the double-peak sizing signal based on the time difference between the two first light signals; Analyzing the injected particles using the mass spectrometry module to obtain mass spectrometry data; Based on the mass spectrometry data, the particle type of each ionized sampled particle and the number of particles corresponding to each particle type are determined respectively; based on the particle type of the sampled particles and the number of particles corresponding to each particle type in the mass spectrometry data, the original source-analyzed distribution of each single-category particle is determined; the original source-analyzed distribution is specifically the number of the single-category particles within each particle size range; the statistical efficiency within each particle size range is calculated based on the bimodal sizing signal and the mass spectrometry data; the ratio of the target number of each particle type in each particle size range of the original source-analyzed distribution to the statistical efficiency corresponding to the particle size range is calculated to obtain a true source-analyzed distribution; Based on the true source-apportioned distribution, the mass concentration of a single type of particles is calculated.

2. The method for calculating aerosol mass concentration according to claim 1, wherein: The calculating of the statistical efficiency in each particle size range based on the bimodal sizing signal and the mass spectrum data specifically includes: generating a bimodal particle size distribution corresponding to the injected particles based on a time difference between the bimodal sizing signals; generating a mass spectral particle size distribution based on the particle information in the mass spectral data and the bimodal size distribution; Based on the bimodal size distribution and mass spectrometry particle size distribution, the statistical efficiency within each particle size range is calculated.

3. The method for calculating aerosol mass concentration according to claim 2, wherein: The using the mass spectrometry module to analyze the sampled particles to obtain mass spectrometry data specifically includes: Calculating the flight speed of the injected particle based on the time difference between the two first light signals and the distance between the two parallel laser beams; Based on the flight speed of the injected particles, the ionization time when the injected particles reach the ionization position is calculated; According to the ionization time, ionization laser is emitted to ionize the sample particles to generate ions, The mass-to-charge ratio of the ions is measured to obtain mass spectrum data of the injected particles.

4. The method for calculating aerosol mass concentration according to claim 3, wherein: Calculating the mass concentration of a single type of particles based on the true source analysis distribution specifically includes: Based on the true source analysis distribution, the aerosol sample is quantitatively analyzed to obtain the true mass concentration corresponding to any substance in all particle size ranges. , the true mass concentration of all substances within any particle size range And the total mass concentration of all substances in all particle size ranges .

5. An aerosol mass concentration calculation device, applied to a single-particle aerosol mass spectrometer source apportionment device, the single-particle aerosol mass spectrometer source apportionment device comprising: Sampling module, diameter measurement module and mass spectrometry module; characterized in that the aerosol mass concentration calculation device specifically includes: An optical signal receiving module is configured to receive, after the aerosol sample is focused into a particle beam using the sampling module, a double-peak sizing signal generated when the sampled particles in the particle beam arrive at the first position of the sizing module, wherein the double-peak sizing signal is generated when the sampled particles arriving at the first position are irradiated by a first laser unit in the sizing module; the laser light generated by the first laser unit is two parallel laser beams; receiving the double-peak sizing signal generated when the sampled particles in the particle beam arrive at the first position of the sizing module specifically comprises: receiving two first optical signals generated by each of the sampled particles sequentially passing through the two parallel laser beams, and generating the double-peak sizing signal based on the time difference between the two first optical signals; Mass spectrometry analysis module: used to analyze the injected particles using the mass spectrometry module to obtain mass spectrometry data; Source apportionment calculation and correction module: used to determine the particle type of each ionized sampled particle and the number of particles corresponding to each particle type based on the mass spectrometry data; determine the original source apportionment distribution of each single-category particle based on the particle type of the sampled particles and the number of particles corresponding to each particle type in the mass spectrometry data; the original source apportionment distribution is specifically the number of the single-category particles in each particle size range; calculate the statistical efficiency in each particle size range based on the bimodal sizing signal and the mass spectrometry data; calculate the ratio of the target number of each particle type in each particle size range of the original source apportionment distribution to the statistical efficiency corresponding to the particle size range to obtain the true source apportionment distribution; Mass concentration calculation module: used to calculate the mass concentration of a single type of particles based on the true source analysis distribution.

6. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the aerosol mass concentration calculation method according to any one of claims 1 to 4 is implemented.

7. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the aerosol mass concentration calculation method according to any one of claims 1 to 4 is implemented.

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