Method for measuring combustion performance of plants in early chalkage environment

Abstract

The invention discloses a method for measuring plant combustion performance in an early chalkage environment, and relates to the technical field of plant combustion performance. In order to understand the combustion characteristics of early chalkiness plants; comprising the following steps: selecting a fiddlehead and gymnosperm species combination in a specific proportion, and simulating early chalkage tropical-subtropical and temperate plant communities; regulating and controlling air pressure, oxygen concentration, temperature and humidity to a geological historical period range through a multi-parameter environment simulation system; and combining parameters such as air pressure, oxygen concentration, material humidity, combustion temperature and residue mass to construct a combustion performance and combustion efficiency calculation method of the ancient plant, and carrying out ancient environment verification. According to the invention, early chalkage air pressure (0.12-0.36 MPa) and oxygen (22%-35%) gradient are simulated through the hyperbaric oxygen chamber, and temperature and humidity partition control (tropical-subtropical VS temperature zone) is combined, so that the reduction degree of a wildfire scene in a geological history period is remarkably improved, and an experimental result is closer to a real ancient ecological background.

Description

Technical Field

[0001] The present invention relates to the technical field of plant combustion performance, and particularly to a method for measuring the combustion performance of plants in the Early Cretaceous environment. Background Art

[0002] In geological history, the Early Cretaceous is an important period, and its environmental conditions and ecosystems are significantly different from those of the modern era. Understanding the combustion performance of plants in this period is of great significance for revealing the evolution of paleoclimate, paleoenvironment, and paleoecology. However, it is extremely difficult to directly study their combustion performance. Therefore, scientists need to adopt indirect methods, such as simulation experiments, to explore the combustion characteristics of plants in this period. The plant communities in the Early Cretaceous were mainly composed of ferns and gymnosperms. Although there are differences in the morphology and structure between modern plants and ancient plants, the chemical composition is less different. During the combustion of Early Cretaceous plants, the release of gases, particulate matter, and the mass of residues are affected by various factors, including plant species, water content, environmental temperature, oxygen concentration, atmospheric pressure, etc.

[0003] In order to accurately simulate the combustion process of Early Cretaceous plants, environmental factors such as the atmospheric composition, atmospheric pressure, temperature, and humidity at that time need to be considered. The atmospheric composition in the Early Cretaceous is significantly different from that of the modern atmosphere, especially the higher oxygen concentration, which will have an important impact on the combustion process of plants. In addition, there are also differences in the climatic conditions in different regions. The environmental conditions in the tropical to subtropical regions are completely different from those in the temperate regions, which will also affect the combustion performance of plants.

[0004] Therefore, in order to deeply study the combustion performance of Early Cretaceous plants, a comprehensive measurement method needs to be developed. This method should be able to simulate the environmental conditions in the Early Cretaceous and analyze the combustion performance and combustion efficiency of plants. Through this method, we can more accurately understand the combustion characteristics of Early Cretaceous plants and provide important clues for revealing the evolution of paleoclimate, paleoenvironment, and paleoecology.

[0005] In summary, the present application proposes a method for measuring the combustion performance of plants in the Early Cretaceous environment, which can simulate the environmental conditions in the Early Cretaceous and provide important scientific basis for the research of paleoclimate, paleoenvironment, and paleoecology. Summary of the Invention

[0006] The purpose of the present invention is to solve the deficiencies in the prior art and propose a method for measuring the combustion performance of plants in the Early Cretaceous environment.

[0007] To achieve the above purpose, the present invention adopts the following technical solutions:

[0008] A method for measuring the combustion performance of plants in the Early Cretaceous environment, comprising the following steps:

[0009] Select a specific proportion of fern and gymnosperm species combinations to simulate the tropical-subtropical and temperate plant communities in the Early Cretaceous;

[0010] Regulate the air pressure, oxygen concentration, temperature and humidity to the range of the geological history period through a multi-parameter environmental simulation system;

[0011] Construct a calculation model for the combustion efficiency of ancient plants by combining air pressure, oxygen concentration, temperature, humidity and residue mass, and conduct paleoenvironmental verification.

[0012] Preferably: the fern species include Osmunda, Alsophila, Gymnosphaera, Dicranopteris, Polypodiodes, Dipteris; the gymnosperm species include Ginkgo, Cycas, Pinus, Abies, Picea, Sequoia, Metasequoia, Araucaria, Agathis, Ephedra, Gnetum, Welwitschia, Taxus, Torreya.

[0013] Further: the combination ratio of the plant communities is set according to the tropical-subtropical and temperate gradients: tropical-subtropical ferns account for 40%-50%, gymnosperms account for 50%-60%; temperate ferns account for 20%-35%, gymnosperms account for 65%-80%.

[0014] Further: the environmental simulation system includes a high-pressure oxygen chamber, the air pressure regulation range is 0.12-0.36 MPa, the oxygen concentration gradient is 22%-35%, the temperature and humidity control accuracy is ±1 °C, where the tropical-subtropical group is set at 30-40 °C and 60%-80% humidity, and the temperate group is set at 15-25 °C and 40%-60% humidity.

[0015] As a preferred solution of the present invention: the combustion kinetic parameters monitor the flame temperature with a resolution of 0.1 °C through an infrared thermal imager, combine a high-speed camera to record the combustion duration, and the ignition delay time is controlled by an electric spark igniter, with the energy set at 10 J and the electrode spacing at 5 mm.

[0016] As a further solution of the present invention: the gas emission characteristic analysis includes real-time monitoring of the CO2 / CO ratio by a mass spectrometer, real-time recording of the emission gas concentration, and determination of the particle size distribution of combustion particles by a laser particle size analyzer.

[0017] As a still further solution of the present invention: establish a calculation method for the combustion performance of ancient plants, comprising the following steps:

[0018] S7-1. Use the range normalization method to standardize the experimental data, where the moisture content is inversely normalized Z xi =(Z max -Z xi) / (Z max -Z min ); The air pressure value, oxygen concentration, temperature, and ignition point are positively correlated with combustibility, and positive normalization is performed [Z xi =(Z xi -Z min ) / (Z max -Z min )].

[0019] S7-2. Calculate the combustion control factor score:

[0020]

[0021] f i is the combustion control factor score value in the principal component analysis; αi is the score coefficient of each component; Z xi is the value after standardizing each index, and n1 is the number of indexes.

[0022] S7-3. Combustion performance calculation formula:

[0023]

[0024] λi is the weight of each principal component; n2 is the number of principal components.

[0025] On the basis of the above scheme: Establish a combustion efficiency calculation method, including the following steps:

[0026] S8-1. Standardize the air pressure P, oxygen concentration O2, temperature T, and humidity H:

[0027]

[0028] where μ i is the variable mean, and σi is the standard deviation.

[0029] S8-2. Apply the theory of the polynomial regression model to calculate the combustion efficiency method of plants. The formula is

[0030] (1) Fit the mass of combustion residues. The formula is

[0031] R = f(P, O2, T, H)

[0032] R - mass of residues;

[0033]

[0034] Constraint conditions: β1 < 0, β2 < 0, β3 < 0, β4 > 0

[0035] P is the air pressure value; O2 is the oxygen concentration; T is the ambient temperature; H is the humidity of the combusted plant;

[0036] β i Calculated by matrix inversion or numerical calculation tools; β0 is the reference residue mass when all independent variables are zero; β1 is the independent change in residue when the air pressure increases by 0.01 MPa; β2 is the independent change in residue when the oxygen concentration increases by 1%; β3 is the independent change in residue when the temperature increases by 1 °C; β4 is the independent change in residue when the humidity increases by 1 unit; β5 is the change in residue under the synergistic effect of air pressure and oxygen; β6 is the change in residue under the synergistic effect of air pressure and temperature; β7 is the change in residue under the synergistic effect of temperature and humidity; β8 is the numerical value of the non-linear effect of oxygen concentration;

[0037] (2) Calculate the combustion efficiency of plants: η = R / M

[0038] η is the combustion efficiency of plants; R is the mass of combustion residues (kg); M is the total amount of plants participating in combustion.

[0039] Based on the foregoing scheme: The combustion efficiency performance index and combustion efficiency are calculated through air pressure, oxygen concentration, combustion temperature, plant humidity, combustion mass, and plant type, and cross-validated with data from Early Cretaceous wildfire sediment layers (such as charcoal fragments). The experimental material pretreatment process includes natural air-drying until the humidity ≤ 10%, vacuum-sealing in a light-proof aluminum foil bag, and storing in a drying oven with a humidity < 15%.

[0040] The beneficial effects of the present invention are as follows:

[0041] 1. A method for measuring the combustion performance of plants in the Early Cretaceous environment, which simulates the air pressure (0.12 - 0.36 MPa) and oxygen gradient (22% - 35%) of the Early Cretaceous through a high-pressure oxygen chamber, combined with temperature and humidity zoning control (tropical - subtropical VS temperate), significantly improves the restoration degree of wildfire scenarios in the geological history period, makes the experimental results closer to the real paleoecological background, and provides key parameters for validating paleoclimate models.

[0042] 2. A method for measuring the combustion performance of plants in the Early Cretaceous environment, which integrates infrared thermal imaging, real-time mass spectrometry monitoring, and laser particle size analysis technologies, realizes the full-scale data coupling from macroscopic combustion behaviors (air pressure, oxygen concentration, ambient temperature, material humidity, residue mass) to microscopic particulate matter components, supports the quantitative construction of combustion performance indexes and combustion efficiency, and provides multi-dimensional calibration basis for wildfire carbon emission models.

[0043] 3. A method for measuring the combustion performance of plants in the Early Cretaceous environment, which adopts a standardized pretreatment process (low-temperature crushing, vacuum sealing) and a repeated experimental design (20 repetitions per group + outlier rejection), effectively eliminates the interference of sample heterogeneity, ensures the statistical significance of combustion performance evaluation, and provides reliable data support for ranking the flammability of different plant groups.

[0044] 4. A method for measuring the combustion performance of plants in the Early Cretaceous environment, combining the observation of the microscopic morphology by scanning electron microscopy and the analysis of organic components by GC-MS, reveals the pore structure of the ash, the formation mechanism of vitrified particles and the generation rule of polycyclic aromatic hydrocarbons, provides an experimental scale for the origin identification of paleo-wildfire residues (such as charred fragments and black carbon), and promotes the cross-validation between geological records and combustion experiments.

[0045] 5. A method for measuring the combustion performance of plants in the Early Cretaceous environment, sets up control experiments of modern atmosphere (21% O2) and ancient high-oxygen gradient (25%-35% O2), combines the dynamic monitoring of CO2 / CO ratio, and for the first time quantifies the threshold effect of oxygen concentration on the combustion efficiency of plants, providing an experimental evidence chain for understanding the mechanism of frequent wildfires and carbon cycle disturbance in the high-oxygen environment of the Early Cretaceous. Description of the Drawings

[0046] Figure 1 is a schematic flow chart of a method for measuring the combustion performance of plants in the Early Cretaceous environment proposed by the present invention. Detailed Embodiments

[0047] The technical solutions of this patent will be further described in detail below in combination with the specific embodiments.

[0048] The embodiments of this patent are described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements with the same or similar functions from beginning to end. The embodiments described below by referring to the drawings are exemplary and are only used to explain this patent and should not be construed as a limitation of this patent.

[0049] Example 1:

[0050] A method for measuring the combustion performance of plants in the Early Cretaceous environment, comprising the following steps:

[0051] S1: Prepare experimental materials for measuring the combustion performance of plants

[0052] The selected fern genera include:

[0053] [[ID=3,3]]Osmunda in Osmundaceae; Alsophila and Gymnosphaera in Cyatheaceae; Dicranopteris in Gleicheniaceae; Polypodium in Polypodiaceae; Dipteris in Dipteridaceae;

[0054] The selected gymnosperm genera include:

[0055] Ginkgo in Ginkgopsida; Cycas in Cycadopsida; Pinus, Abies, Picea, Sequoia, Metasequoia, Araucaria, Agathis in Coniferopsida; Ephedra, Gnetum, Welwitschia in Gnetopsida; Taxus and Torreya in Taxopsida;

[0056] In the Early Cretaceous, the fern and gymnosperm assemblages in tropical to subtropical regions were as follows: ferns accounted for 40%-50% of the species, and gymnosperms accounted for 50%-60% of the species; in temperate regions, the fern and gymnosperm assemblage was: ferns accounted for 20%-35% of the species, and gymnosperms accounted for 80%-65% of the species;

[0057] S2: Pretreatment of experimental materials:

[0058] Naturally air-dry the experimental materials to a constant weight (humidity ≤ 10%), avoiding photodegradation caused by direct sunlight, vacuum-seal them in a light-proof aluminum foil bag, and store them in a drying oven (humidity < 15%);

[0059] S3: Simulate the measurement environment

[0060] Use a hyperbaric oxygen chamber to adjust the air pressure range from 0.12 to 0.36 MPa (simulating the air pressure gradient from the Earth's surface to low altitude in the Early Cretaceous), the oxygen concentration from 22% to 35% (set in gradients based on the paleoatmospheric model), equipped with a temperature and humidity control system (15 - 50 °C), among which the tropical - subtropical group: 30 - 40 °C, humidity 60% - 80%, and the temperate group: 15 - 25 °C, humidity 40% - 60%;

[0061] Use a gas analyzer to monitor the concentrations of CO2, CO, CH4, NO X 、SO2 and the particle size of particulate matter (PM10, PM2.5) in real time, measured by the beta-ray method;

[0062] Use a combustion parameter instrument to record the ignition delay time (accuracy ±0.1 s), flame temperature (infrared thermal imager, resolution 0.1 °C), and combustion duration (record the flame dynamics with a high-speed camera);

[0063] Scanning electron microscope (SEM): Observe the pore structure of the ash (acceleration voltage 5 kV, magnification 1000×);

[0064] GC-MS: Qualitative and quantitative analysis of organic components (DB-5MS chromatographic column, helium carrier gas);

[0065] Thermogravimetric analyzer (TGA): Determine the mass loss rate (heating rate 10 °C / min, N2 atmosphere);

[0066] S4: Measure the combustion performance of plants through experiments

[0067] S41: Set the air pressure and oxygen concentration

[0068] According to the oxygen gradient of the Early Cretaceous atmospheric model, set 4 groups of experimental groups (O2 concentrations are 21%, 25%, 30%, 35% respectively), and the control group is the modern atmosphere (21%);

[0069] Control the temperature and humidity

[0070] For the tropical - subtropical group, set the temperature at 30 - 40°C and the humidity at 60% - 80%; for the temperate group, set the temperature at 15 - 25°C and the humidity at 40% - 60%.

[0071] S42: Combustion experiment design

[0072] Mix 200 g of plant samples (mix ferns and gymnosperms in proportion) and spread them evenly on an alumina refractory tray (size 50×50 cm).

[0073] Use an electric spark igniter to ignite the central area of the sample. The electric spark igniter (energy 10 J, electrode spacing 5 mm), and record the ignition success time (≤30 seconds is considered a valid ignition).

[0074] Repeat each set of parameters 20 times, excluding outliers (such as ignition failure or combustion interruption) to ensure data reliability.

[0075] S43: Real - time data acquisition

[0076] An infrared thermal imager records the maximum temperature and temperature distribution. The infrared thermal imager scans once every 0.5 seconds to generate a thermal map.

[0077] A mass spectrometer samples every second and records the CO2 / CO ratio and the peak concentration of toxic gases (such as an alarm when CO > 100 ppm).

[0078] A laser particle size analyzer monitors the PM2.5 particle size distribution (0.1 - 10 μm) in real - time. After sampling with a filter membrane, the K + , Ca 2+ content is determined by ion chromatography.

[0079] S44: Residue analysis

[0080] After the combustion residue cools to room temperature, weigh it and calculate the mass loss rate: (original weight - residual weight) / original weight × 100%.

[0081] Observe the surface structure of the ash (such as porosity, vitrified particles) with a scanning electron microscope.

[0082] Analyze the soluble organic matter (such as tar, polycyclic aromatic hydrocarbons) in the residue by Soxhlet extraction, and identify the components by GC - MS.

[0083] S45: Data processing and model verification

[0084] Calculate the combustion performance and combustion efficiency based on air pressure, oxygen concentration, combustion temperature, plant humidity, mass of the combustible, and plant type.

[0085] Establish a calculation method for combustion performance, including the following steps:

[0086] S7-1. Standardize the experimental data using the range normalization method, where the moisture content is inversely standardized as Z xi =(Z max -Z xi ) / (Z max -Z min ); The air pressure value, oxygen concentration, temperature, and ignition point are positively correlated with combustibility, and are directly standardized as [Z xi =(Z xi -Z min) ) / (Z max -Z min )].

[0087] S7-2. Calculate the combustion control factor score:

[0088]

[0089] f i is the score value of the combustion control factor in the principal component analysis; α i is the score coefficient of each component; Z xi is the value after standardizing each index, and n1 is the number of indexes.

[0090] S7-3. Combustion performance calculation:

[0091]

[0092] λ i is the weight of each principal component; n2 is the number of principal components;

[0093] Establish a combustion efficiency calculation method, including the following steps:

[0094] S8-1. Standardize the air pressure P, oxygen concentration O2, temperature T, and humidity H:

[0095]

[0096] where μ i is the variable mean, and σ i is the standard deviation.

[0097] S8-2. Apply the theory of the polynomial regression model to calculate the combustion efficiency of plants. The formula is

[0098] (1) Fit the mass of combustion residues. The formula is

[0099] R = f(P, O2, T, H)

[0100] R is the residue;

[0101]

[0102] Constraints: β1 < 0, β2 < 0, β3 < 0, β4 > 0

[0103] P is the air pressure value; O2 is the oxygen concentration; T is the ambient temperature; H is the humidity of the burning plant;

[0104] β i Calculated by matrix inversion or numerical calculation tools (such as numpy.linalg.inv in Python); β0 is the reference residue mass when all independent variables are zero; β1 is the independent change in residue when the air pressure increases by 0.01 MP; β2 is the independent change in residue when the oxygen concentration increases by 1%; β3 is the independent change in residue when the temperature rises by 1 °C; β4 is the independent change in residue when the humidity increases by 1 unit; β5 is the change in residue under the synergistic effect of air pressure and oxygen; β6 is the change in residue under the synergistic effect of air pressure and temperature; β7 is the change in residue under the synergistic effect of temperature and humidity; β8 is the numerical value of the non - linear effect of oxygen concentration;

[0105] Combustion efficiency of the plant: η = R / M

[0106] R is the residue mass; M is the combustion mass of the plant;

[0107] Compare the experimental results with the data of Early Cretaceous wildfire sediment layers (such as charcoal fragments, black carbon isotopes) to verify the reliability of the simulation.

[0108] Example 2:

[0109] A method for measuring the combustion performance of plants in the Early Cretaceous environment. To facilitate the determination of the combustion performance of plants in different environments, in this example, combustion performance experiments are carried out using the four experimental groups and the control group in step S41 of Example 1. The experimental results are shown in Table 1:

[0110]

[0111]

[0112] Table 1

[0113] The following conclusions can be drawn from Table 1:

[0114] (1) Combustion performance:

[0115] Increases significantly with the increase in oxygen concentration. The tropical - subtropical group burns more fully due to high temperature and high humidity conditions, and its combustion performance is higher than that of the temperate group;

[0116] (2) Mass loss rate:

[0117] Burning is more complete at high oxygen concentrations, and the mass loss rate is higher;

[0118] (3) CO2 / CO ratio:

[0119] The increase in oxygen concentration promotes complete combustion, resulting in an increase in the proportion of CO2 and a decrease in the generation of CO.

[0120] As described above, this is a preferred specific embodiment of the present invention. The protection scope of the present invention is not limited thereto. Any modification, equivalent replacement, improvement, etc. made by those skilled in the art within the technical scope disclosed by the present invention in combination with the prior art or common knowledge, within the spirit and principle of the present invention, shall be covered by the protection scope of the present invention.

Claims

1. A method for measuring the combustion performance of plants in the Early Cretaceous environment, characterized in that, It includes the following steps: Select a specific proportion of fern and gymnosperm species combinations to simulate the Early Cretaceous tropical-subtropical and temperate plant communities; Regulate the air pressure, oxygen concentration, temperature and humidity to the range of the geological history period through a multi-parameter environmental simulation system; Construct a calculation model for the combustion performance and combustion efficiency of ancient plants by combining air pressure, oxygen concentration, temperature, humidity, and residue mass, and conduct paleoenvironmental verification.

2. The method for measuring the combustion performance of plants in the early Cretaceous environment according to claim 1, characterized in that The fern species include Osmunda, Alsophila, Gymnosphaera, Dicranopteris, Polypodiodes, Dipteris; the gymnosperm species include Ginkgo, Cycas, Pinus, Abies, Picea, Sequoia, Metasequoia, Araucaria, Agathis, Ephedra, Gnetum, Welwitschia, Taxus, Torreya.

3. A method for measuring the combustion performance of plants in the Early Cretaceous environment according to claim 2, characterized in that The combination ratio of the plant communities is set according to the tropical-subtropical and temperate gradients: tropical-subtropical ferns account for 40%-50%, gymnosperms account for 50%-60%; temperate ferns account for 20%-35%, gymnosperms account for 65%-80%.

4. A method for measuring the combustion performance of plants in the Early Cretaceous environment according to claim 3, characterized in that, The environmental simulation system includes a high-pressure oxygen chamber, the air pressure regulation range is 0.12-0.36 MPa, the oxygen concentration gradient is 22%-35%, the temperature and humidity control accuracy is ±1 °C, of which the tropical-subtropical group is set at 30-40 °C and 60%-80% humidity, and the temperate group is set at 15-25 °C and 40%-60% humidity.

5. A method for measuring the combustion performance of plants in the Early Cretaceous environment according to claim 4, characterized in that, The combustion kinetic parameters monitor the flame temperature with a resolution of 0.1 °C by an infrared thermal imager, record the combustion duration in combination with a high-speed camera, and the ignition delay time is controlled by an electric spark igniter, with the energy set at 10 J and the electrode spacing at 5 mm.

6. A method for measuring the combustion performance of plants in the Early Cretaceous environment according to claim 5, characterized in that The analysis of the gas emission characteristics includes real-time monitoring of the CO2 / CO ratio by a mass spectrometer, real-time recording of the emission gas concentration, and determination of the particle size distribution of the combustion particulates by a laser particle size analyzer.

7. A method for measuring the combustion performance of plants in the Early Cretaceous environment according to claim 6, characterized in that, Establish a calculation method for the combustion performance of ancient plants, including the following steps: S7-1. Standardize the experimental data using the range normalization method, where the moisture content is inversely standardized as Z xi =(Z max -Z xi ) / (Z max -Z min ); The air pressure value, oxygen concentration, temperature, ignition point are positively correlated with combustibility, and are positively standardized as [Z xi =(Z xi -Z min ) / (Z max -Z min )]. S7-2. Calculate the combustion control factor score: f i is the score value of the combustion control factor in the principal component analysis; a i is the score coefficient of each component; z xi is the value after standardizing each index, and n1 is the number of indexes. S7-3. Combustion performance calculation formula: λ i is the weight of each principal component; n2 is the number of principal components.

8. A method for measuring the combustion performance of plants in the Early Cretaceous environment according to claim 7, characterized in that, Establish a calculation method for the combustion efficiency, including the following steps: S8-1. Standardize the air pressure P, oxygen concentration O2, temperature T, and humidity H: where μ i is the variable mean, and σ i is the standard deviation. S8-2. Apply the theoretical calculation method of the polynomial regression model to calculate the combustion efficiency of plants. The formula is (1) Fit the combustion residue mass, the formula is R = f(P, O2, T, H) R - residue mass; Constraint conditions: β1 < 0, β2 < 0, β3 < 0, β4 > 0 P is the air pressure value; O2 is the oxygen concentration; T is the environmental temperature; H is the humidity of the combusted plant; β i Calculated by matrix inversion or numerical calculation tools; β0 is the reference residue mass when all independent variables are zero; β1 is the independent change in residue when the air pressure increases by 0.01 MP; β2 is the independent change in residue when the oxygen concentration increases by 1%; β3 is the independent change in residue when the temperature increases by 1 °C; β4 is the independent change in residue when the humidity increases by 1 unit; β5 is the change in residue under the synergistic effect of air pressure and oxygen; β6 is the change in residue under the synergistic effect of air pressure and temperature; β7 is the change in residue under the synergistic effect of temperature and humidity; β8 is the numerical value of the non-linear effect of oxygen concentration; (2) Calculate the combustion efficiency of plants: η = R / M η is the combustion efficiency of plants; R is the mass of the combustion residue (kg); M is the total mass of the plants participating in the combustion (kg).

9. A method for measuring the combustion performance of plants in the Early Cretaceous environment according to claim 8, characterized in that, The combustion efficiency performance and combustion efficiency are calculated through air pressure, oxygen concentration, combustion temperature, plant humidity, combustion mass, and plant type, and cross-validated with the data of the Early Cretaceous wildfire sediment layer (such as charcoal fragments). The pretreatment process of the experimental materials includes natural air drying to a humidity ≤ 10%, vacuum sealing in a light-proof aluminum foil bag, and storing in a drying oven with a humidity < 15%.

Images