Discharge plasma reaction path mapping and analysis method based on node force relationship

Abstract

The present application relates to gas discharge technology, specifically relates to discharge plasma reaction path mapping and analysis method based on node force relationship, including deriving the time-varying data of parameters such as substance number density, reaction rate and reduced field strength from the simulation model of atmospheric pressure wet air discharge, and forming the initial reaction system layout in two-dimensional space according to the data. The force rules between nodes are formulated. According to the force of the node, iteration is carried out, and finally the stable reaction system layout is obtained; based on the information in the drawing image, the correlation between the substances and the importance of the substances to the system are distinguished from the complex reaction system according to the node arrangement. Compared with the traditional reaction path diagram, the calculation and analysis method does not need manual arrangement, is more simple, and is more in line with the internal physical facts of the reaction system; compared with the traditional analysis method considering only the number density of the substance, the role of the substance in the connected reaction system is considered.

Description

Technical Field

[0001] This invention belongs to the field of gas discharge technology, and specifically relates to a method for drawing and analyzing discharge plasma reaction paths based on nodal force relationships. Background Technology

[0002] The atmospheric pressure humid air low temperature plasma discharge process involves dozens of substances, mainly nitrogen, oxygen and water vapor, including their numerous reaction products, as well as hundreds or thousands of reactions. Analyzing the correlation and system structure of substances in this highly nonlinear system is quite difficult.

[0003] In global model simulation studies, the changes in the number density of each substance are affected by chemical reactions. The reaction path diagram drawn based on the generation and consumption relationship of each substance is helpful for us to understand the reaction system.

[0004] Due to the complexity of the reaction system, traditional reaction path drawing often makes it difficult to arrange the distribution of substances in the diagram. Manually specifying the arrangement of substances based on their correlation is time-consuming and laborious, and the arrangement of substances is difficult to balance aesthetics and logic.

[0005] In simplified analysis of reaction systems, the traditional method for determining the importance of substances is to analyze the relationship between substance number density and electron number density, setting a screening threshold to judge the importance of a substance in the reaction system. The chemical reaction rate is the product of the reaction rate constant and the number density of each reactant, directly influenced by substance number density; substances with higher number densities tend to participate in faster reaction rates, making screening for important particles based on substance number density reasonable. However, when assessing the importance of a substance to a reaction system, its substance number density should not be the sole criterion; its correlation with other substances should also be considered. Some substances may have high number densities but only interact with a few particles in their formation or consumption, while others may have low number densities but play an irreplaceable role as intermediate products in the reaction system. Summary of the Invention

[0006] To address the problems existing in the background technology, the present invention provides a method for conveniently drawing chemical reaction pathway diagrams involved in discharge and analyzing atmospheric pressure humid air reaction systems based on the topology, mass density, and reaction rate of the reaction system.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a method for drawing and analyzing discharge plasma reaction paths based on nodal force relationships, comprising the following steps:

[0008] Step 1: Extract the data on the changes of mass number density, reaction rate and reduced field strength over time from the atmospheric pressure wet air discharge simulation model, and form the initial reaction system layout in two-dimensional space based on the data;

[0009] Step 2: Formulate the force rules between nodes, and iterate according to the force on the nodes to obtain the layout of the reaction system;

[0010] Step 3: Analyze the interrelationships of substances and the importance of substances to the reaction system by examining the node arrangement of the reaction system layout.

[0011] In the above-mentioned method for drawing and analyzing discharge plasma reaction paths based on nodal force relationships, step 1 includes: taking the types of substances in the reaction system as nodes in a two-dimensional space, with the node value being the substance number density value; taking the reaction generated between substances as a directed edge, with the starting point being the reactant in the reaction formula and the ending point being the product in the reaction formula, the edge length value being the reciprocal of the reaction rate value, and the edge width and opacity value being the reaction rate value.

[0012] In the above-mentioned method for drawing and analyzing discharge plasma reaction paths based on nodal force relationships, step 2 includes the following specific steps:

[0013] Step 2.1: The forces between nodes include attraction and repulsion; the repulsion between nodes is positively correlated with the product of the magnitudes of the two nodes and negatively correlated with the distance between the nodes; the attraction between nodes is positively correlated with the difference between the length of the edge between the nodes and the current distance between the nodes.

[0014] Step 2.2: Derive the reaction rate change data over time from the model, sum the rates of all reactions where reactant i contains product j, and denot this sum as R. ij Within a single time step, two nested loops are performed. The first loop iterates through each node j and calculates the repulsive force F between two points. cij With gravity F hij The net force at node i is accumulated, and the net force on all nodes is obtained by traversing node i in the second layer. Then, the damped velocity V under the influence of the forces on all nodes is calculated iteratively. i And update position P i The total kinetic energy of the system is calculated once at each time step. The iteration ends if the total kinetic energy is 0.

[0015] In the above-mentioned method for drawing and analyzing discharge plasma reaction paths based on nodal force relationships, step 3 includes the following specific steps:

[0016] Step 3.1: Take the logarithm of the density values ​​and reaction rate values ​​for each type of substance, specifically as follows:

[0017] Ni.D=1.5*|log10(Densityi)| (1)

[0018] L ij .wid = (log 10 (rate ij (2) + 15) / 10

[0019] L ij .len = 100 / ((log 10 (rate ij (3) + 15) / 18)

[0020] L ij .opacity = (log 10 (rate ij ))+15) / 18 (4)

[0021] Density i N represents the average number density of substance i during the selected time period. i Let N be the node corresponding to the i-th substance, and its attribute N i .D represents the magnitude of the node corresponding to the i-th substance, L ij All are from node N i Pointing to N j A directed edge, the sum of the reaction rates of substance i in the formation of substance j, and its property L ij .wid represents the width of the directed edge, L ij .len represents the natural length of the directed edge, L ij .opacity represents the opacity of the directed edge, with a value ranging from 0 to 1;

[0022] Step 3.2: Randomly assign initial positions to the nodes corresponding to each type of material and then perform force analysis;

[0023] The forces between nodes i and j include the repulsive force F between nodes, which is affected by the size of the nodes and the distance between them. c The inter-node gravitational force F, which is influenced by the natural length of the directed edge between nodes and the current distance between nodes. h ;

[0024] The repulsive force F between nodes i and j c With gravity F h The calculation is as follows:

[0025] F cij =k c *N i .D*N j .D / (Dis ij 2 (5)

[0026] F hij =k h *(Dis ij -L ij .len) (6)

[0027] Where kc N is the repulsion coefficient. i D and N j .D represents the magnitude of node i and node j, respectively. ij L is the distance between node i and node j at the current time step. ij .len is the natural length of the directed edge between node i and node j;

[0028] Step 3.3: After two rounds of iterative traversal of each node, the net force acting on each node is equal to the sum of the repulsive and attractive forces between it and all other points.

[0029] F i =Σ(Fc ij +Fh ij (7)

[0030] The node undergoes damped motion under the influence of forces within the current time step, and its velocity after iteration is expressed as:

[0031] V i '=(V i +F i *t d / m i )*k damp (8)

[0032] Where V i V represents the velocity at the previous time step. i 'm' represents the velocity at the current time step after force analysis. i k is the mass of the substance. damp As the damping coefficient is used, the particle velocity gradually decreases with iteration, and the system tends to stabilize.

[0033] Step 3.4: Calculate the current time step velocity and then update the material position P. i Its expression is:

[0034] P i '=P i +V i '*t d (9)

[0035] The total kinetic energy of the system is calculated by the following formula:

[0036] E=ΣM i *V i 2 (10)

[0037] The system stops iterating when the total kinetic energy of the system is 0.

[0038] Compared with existing technologies, the beneficial effects of this invention are as follows: Under the influence of the defining forces between nodes, the types of substances represented by the nodes automatically update their positions in two-dimensional space, which is simpler than traditional reaction path diagrams that do not require manual arrangement. The distance between substances and their proximity to the center in the reaction path diagram can intuitively show the strength of the correlation between substances in the system and their importance to the reaction system. This reaction path diagram allows for intuitive analysis of complex and highly nonlinear chemical reaction systems, and it is more consistent with the inherent physical facts of the reaction system than traditional reaction path diagrams. By analyzing the importance of substances to the system through their proximity to the center, this method of analyzing key particles takes into account the role of substances in the connected reaction system, compared to traditional methods that only consider the number density of substances. Attached Figure Description

[0039] Figure 1 This is a flowchart of the calculation method for visualizing and analyzing the reaction path of an atmospheric pressure humid air discharge reaction system based on nodal force relationships, according to an embodiment of the present invention.

[0040] Figure 2 This is a reaction path diagram of each substance in the global model simulation of atmospheric pressure wet air discharge plasma obtained by the calculation method of one embodiment of the present invention;

[0041] Figure 3 This is a schematic diagram of the reaction path diagram of the global model simulation of atmospheric pressure humid air discharge plasma according to an embodiment of the present invention, showing the situation near water vapor.

[0042] Figure 4 This is a reaction pathway diagram of each substance in the discharge process obtained by changing the initial water vapor molar ratio to 1e-6 according to an embodiment of the present invention;

[0043] Figure 5 This is a schematic diagram of the situation near water vapor in the discharge process reaction path diagram obtained by changing the initial water vapor molar ratio to 1e-6 according to one embodiment of the present invention;

[0044] Figure 6 This is a schematic diagram showing the change of negative ion particle number density over time obtained from atmospheric pressure humid air discharge simulation under different humidity conditions according to an embodiment of the present invention.

[0045] Figure 7 This is a schematic diagram showing the change of positive ion particle number density over time obtained from atmospheric pressure wet air discharge simulation under different humidity conditions in one embodiment of the present invention. Detailed Implementation

[0046] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0047] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0048] The present invention will be further described below with reference to specific embodiments, but these are not intended to limit the scope of the invention.

[0049] This embodiment describes a method for drawing and analyzing discharge plasma reaction paths based on nodal force relationships, including the following steps:

[0050] S1. Data on the time-varying parameters such as mass number density, reaction rate, and reduced field strength are derived from the atmospheric pressure humid air discharge simulation model, and the initial reaction system layout is formed in two-dimensional space based on this data.

[0051] S2. Establish the force rules between nodes. Iterate based on the forces acting on the nodes to ultimately obtain a stable reaction system layout.

[0052] S3. Based on the information in the image drawn in S1, analysis can be performed to identify the interrelationships of substances and their importance to the system from the node arrangement in a complex reaction system. This calculation and analysis method is simpler than traditional reaction path diagrams, which do not require manual arrangement, and is more consistent with the inherent physical facts of the reaction system; compared with traditional analysis methods that only consider the number density of substances, it takes into account the role of substances in the connected reaction system.

[0053] Furthermore, S1 includes the following specific steps:

[0054] 1) Because the number density of substances and the reaction rate span multiple orders of magnitude, the data are processed to the logarithm of 10 in order to clearly reflect the relationship between substances in the graph. The types of substances in the reaction system are treated as nodes in a two-dimensional space, and the node values ​​are taken as the number density values; the reactions between substances are treated as directed edges, with the starting point being the reactant in the reaction formula and the ending point being the product in the reaction formula. The edge length is taken as the reciprocal of the reaction rate value, and the edge width and opacity values ​​are taken as the reaction rate values.

[0055] 2) The forces between nodes are divided into attractive and repulsive forces. The repulsive force between nodes is positively correlated with the product of the magnitudes of the two nodes and negatively correlated with the distance between the nodes; the attractive force between nodes is positively correlated with the difference between the length of the edge between the nodes and the current distance between the nodes.

[0056] 3) The force acting on the node causes damped motion at the current time step, and after updating the position, the next iteration begins until the reaction system is stable.

[0057] Furthermore, S2 includes the following specific steps:

[0058] 1) Analyzing the distance of a substance from the center of the image can reveal the importance of that substance in the reaction system. The closer the substance is to the center, the more important it is to the reaction system.

[0059] 2) Analyzing the distance between two substances can reveal the correlation between their number densities in the system. The closer the distance, the stronger the correlation between the two substances in the system, and the number densities often rise or fall synchronously.

[0060] 3) Analyzing the density of nodes and edges around the density node of the same substance under different simulation conditions can help analyze the changes in its importance in the reaction system.

[0061] In specific implementation, such as Figure 1 As shown, the method for drawing and analyzing discharge plasma reaction paths based on nodal force relationships includes: deriving time-varying data for parameters such as mass number density, reaction rate, and reduced field strength from an atmospheric pressure humid air discharge simulation model, and forming an initial reaction system layout in two-dimensional space based on this data; formulating force rules between nodes; and iterating based on the nodal forces to finally obtain a stable reaction system layout. Specifically, the steps involve summing the time-varying reaction rates of all reactions involving reactants i and products j, denoted as R. ij Within a single time step, two nested loops are performed. The first loop iterates through each node j and calculates the repulsive force F between two points. cij With gravity F hij The net force at node i is accumulated, and the net force on all nodes is obtained by traversing node i in the second layer. Then, the damped velocity V under the influence of the forces on all nodes is calculated iteratively. i And update position P i The total kinetic energy of the system is calculated once at each time step. The iteration ends if the total kinetic energy is 0.

[0062] In atmospheric pressure humid air discharge, the density and reaction rate values ​​of various substances span tens of orders of magnitude. Directly using these values ​​as references for node size and edge length and width would result in significant discrepancies. To clearly reflect the relationships between substances in the diagram, the data is processed using the logarithm of 10. The substances in the reaction system are represented as nodes in a two-dimensional space, with node values ​​based on the substance number density. Reactions between substances are represented as directed edges, starting from reactants and ending at products. Edge length is the reciprocal of the reaction rate, while edge width and opacity are also based on the reaction rate. The forces between nodes are divided into attractive and repulsive forces. The repulsive force is positively correlated with the product of the two node sizes and negatively correlated with the distance between nodes. The attractive force is positively correlated with the difference between the edge length and the current distance between nodes. The forces acting on nodes cause damped motion at the current time step, updating the position before the next iteration, until the reaction system stabilizes.

[0063] To identify the correlation relationships and importance of substances in a complex reaction system, the following methods can be used: Analyzing the distance of a substance from the center of the image can reveal its importance in the reaction system; the closer the substance is to the center, the more important it is. Analyzing the distance between two substances can reveal the correlation between their number densities in the system; the closer the distance, the stronger the correlation between the two substances in the system, and their number densities often rise or fall synchronously. Analyzing the density of nodes and edges around the density nodes of the same substance under different simulation conditions can reveal changes in its importance in the reaction system.

[0064] Example 1

[0065] The reaction was carried out under the following conditions: atmospheric pressure air discharge gap of 4mm, applied voltage of 15kV, temperature of 300K, and air pressure of 760Pa. The humid air was a mixture of nitrogen, oxygen and water vapor in a ratio of 79:20:1. The reaction path of the reaction system was visualized and analyzed during a certain period of time.

[0066] Table 1. All particles contained in the reaction system

[0067]

[0068] In atmospheric pressure humid air discharge, the density and reaction rate values ​​of various substances span tens of orders of magnitude. If their density and reaction rate values ​​are directly used as references for node size and side length and width, the discrepancies would be too large. Therefore, their logarithms are taken:

[0069] Ni.D=1.5*|log10(Densityi)| (1)

[0070] Lij .wid = (log 10 (rate ij (2) + 15) / 10

[0071] L ij .len = 100 / ((log 10 (rate ij (3) + 15) / 18)

[0072] L ij .opacity = (log 10 (rate ij ))+15) / 18 (4)

[0073] Density i N represents the average number density of substance i during the selected time period. i Let N be the node corresponding to the i-th substance, and its attribute N i .D represents the magnitude of the node corresponding to the i-th substance, L ij All are from node N i Pointing to N j A directed edge, the sum of the reaction rates of substance i in the formation of substance j, and its property L ij .wid represents the width of the directed edge, L ij .len represents the natural length of the directed edge, L ij .opacity represents the opacity of the directed edge (with a value between 0 and 1).

[0074] After randomly assigning initial positions to nodes corresponding to each type of material, force analysis is performed.

[0075] When performing force analysis between two nodes i and j, the force is divided into inter-node repulsive force F, which is affected by the size of the nodes and the distance between them. c The inter-node gravitational force F, which is influenced by the natural length of the directed edge between nodes and the current distance between nodes. h .

[0076] The repulsive force F between nodes i and j c With gravity F h The calculation is as follows:

[0077] F cij =k c *N i .D*N j .D / (Dis ij 2 (5)

[0078] F hij =k h *(Disij -L ij .len) (6)

[0079] Where k c N is the repulsion coefficient. i D and N j .D represents the magnitude of node i and node j, respectively. ij L is the distance between node i and node j at the current time step. ij .len is the natural length of the directed edge between node i and node j.

[0080] After two rounds of iterative traversal of each node, the net force acting on each node is equal to the sum of the repulsive and attractive forces between it and all other nodes.

[0081] F i =Σ(Fc ij +Fh ij (7)

[0082] The node undergoes damped motion under the influence of forces within the current time step, and its velocity after iteration is expressed as:

[0083] V i '=(V i +F i *t d / m i )*k damp (8)

[0084] Where V i V represents the velocity at the previous time step. i 'm' represents the velocity at the current time step after force analysis. i For specific types of substances, such as nitrogen, oxygen, and water vapor, a larger mass can be used to ensure relatively stable positions, while other substances can use the same default value; k damp The damping coefficient causes the particle velocity to gradually decrease with each iteration, thus stabilizing the system.

[0085] Once the current time step velocity is calculated, the matter position P can be updated. i Its expression is:

[0086] P i '=P i +V i '*t d (9)

[0087] The total kinetic energy of the system is calculated by the following formula:

[0088] E=ΣM i *V i 2(10)

[0089] The system stops iterating when the total kinetic energy reaches 0. The current steady state, i.e., the reaction roadmap, is obtained and plotted. Figure 2 The diagram shown illustrates the reaction pathways of various substances in a global model simulation of atmospheric pressure wet air discharge plasma with an applied voltage of 15kV, a gap of 4mm, a temperature of 300K, and an initial water vapor molar ratio of 1e-2.

[0090] analyze Figure 2 As can be seen, in this embodiment 1, the discharge plasma reaction path drawing and analysis method based on nodal force relationships will exert a greater gravitational force on particles with higher generation rates for other types of matter. Since this embodiment uses atmospheric pressure humid air discharge plasma, the particle number density of nitrogen and oxygen is much higher than that of other particles. Electrons, as the most active particles in the discharge process, are also of significant importance. Therefore, these three types of particles form the center of the reaction system, and the remaining particles are arranged from the inside out according to their importance to the reaction system. Although the excited-state particles of nitrogen and oxygen molecules have a high number density, they only have reaction pathways with their ground-state particles. The forces exerted on them by other particles are mainly repulsive, so the net force they experience should be to move them away from the center of the reaction system. Therefore, by observing the reaction path diagram, the importance of different types of matter to the reaction system can be intuitively determined.

[0091] Example 1 is a study of atmospheric pressure humid air discharge plasma. During the reaction, charged particles are relatively active, while the accumulation of neutral particles often takes place over a considerable period after the discharge. The number density of positive and negative ions during the discharge process can also be studied using the reaction path diagram of the atmospheric pressure humid air discharge reaction system based on nodal force relationships generated in Example 1.

[0092] There is no obvious direct pathway between nitrate ions and water vapor molecules, but they are quite close in the reaction pathway diagram. This means that although they do not have a direct generation-consumption relationship, their number densities are strongly correlated when connected by other substances in the nonlinear system as intermediate products. For example... Figure 6 As shown, the results of negative ion particle number density changes over time obtained from atmospheric pressure wet air discharge simulations under different humidity levels were compared. It was found that among several key negative ions, nitrate ions showed the most significant difference in variation with humidity. Correlation analysis confirmed a strong correlation between the mass density of water vapor molecules and nitrate ions. Similar analysis can be performed on the more important positive ions during the discharge process, such as... Figure 7 The analysis of the actual critical positive ion number density over time under different humidity levels shows that hydrated hydrogen ions are more sensitive to humidity among the critical positive ions. Figure 3 and Figure 5In the simulation, among the nodes surrounding the node corresponding to the water vapor molecule, the closest node is precisely the node corresponding to the hydrated hydrogen ion, which is consistent with the result obtained from the simulation calculation. That is, the reaction path diagram of the atmospheric pressure humid air discharge reaction system based on the nodal force relationship drawn in Example 1 can accurately and intuitively reflect the physical facts of the changes in the number density of matter in the actual atmospheric pressure humid air discharge plasma.

[0093] This demonstrates that the visualization and analysis method for the reaction path of the atmospheric pressure wet air discharge reaction system based on nodal force relationships does not rely on direct generation or consumption relationships, but intuitively reveals the strength of the correlation between substances in a nonlinear system. This is significant for the regulation of low-temperature plasma. It means that by observing the generated reaction path diagram, when it is necessary to increase the generation of the target product, the number density of the substance types corresponding to the nodes that are strongly correlated with it in the path diagram can be increased during the discharge.

[0094] In the simulation study, humidity is characterized by the water vapor molar ratio. When different initial water vapor molar ratios are adopted, the reaction path diagram generated by the simulation process can clearly show the changes in the role of water vapor in the reaction system under different humidity levels.

[0095] Figure 3 This is the situation near the nodes corresponding to water vapor molecules in the reaction pathway diagram when the initial molar ratio of water vapor is 1e⁻². Figure 5 This is the situation near the nodes corresponding to water vapor molecules in the reaction pathway diagram when the initial molar ratio of water vapor is 1e⁻⁶. This can be derived from... Figure 3 , Figure 4 The comparison clearly shows that when humidity increases, the number of nodes around the nodes corresponding to water vapor molecules increases, and the number, width and opacity of directed edges also increase, which means that the importance of water vapor molecules in the system is significantly enhanced.

[0096] Therefore, we can conclude that the discharge plasma reaction path drawing and analysis method based on nodal force relationship proposed in this embodiment is simpler to draw reaction path diagrams than traditional methods, and the visual effect is more beautiful, and the interface layout is more logical in relation to the relevant physical facts.

[0097] The above are merely preferred embodiments of the present invention and are not intended to limit the implementation methods and protection scope of the present invention. Those skilled in the art should recognize that any equivalent substitutions and obvious changes made based on the content of this specification should be included within the protection scope of the present invention.

Claims

1. A method for discharge plasma reaction path mapping and analysis based on nodal force relationships, characterized by, The method comprises the following steps: Step 1, data of the number density of substances, reaction rate and reduced field strength changing with time are derived from a simulation model of discharge in atmospheric moist air, and an initial reaction system layout is formed in a two-dimensional space according to the data; the specific steps are as follows: The species in the reaction system are taken as nodes in the two-dimensional space, and the node value is the number density value; the generation reaction between substances is taken as a directed edge, the starting point is the reactant in the reaction formula, the end point is the product in the reaction formula, the edge length value is the inverse of the reaction rate value, and the edge width and opacity value are the reaction rate value; Step 2, a force rule between nodes is formulated, and iteration is carried out according to the force of nodes to obtain the reaction system layout; the specific steps are as follows: Step 2.1, the force between nodes includes attraction and repulsion; wherein the repulsion between nodes is positively correlated with the product of the size values of two nodes and is negatively correlated with the distance between nodes; the attraction between nodes is positively correlated with the difference between the length of the edge and the current distance between nodes; Step 2.

2. Derive reaction rate versus time data from the model, include i products j Sum the rates of all reactions and call this R ij ; perform a two-layer loop over a single time step, the first layer iterating over each node j calculating the repulsive force between two points F cij and the attractive force F hij accumulating the net force on the node i , the second layer iterating over each node i to get the net force on all nodes; Subsequently, the damping motion velocity of all nodes under the force influence is calculated in a loop V i and updating the position P i The total kinetic energy of the system is calculated in each time step, and the iteration ends if the total kinetic energy is 0. Step 3, the node arrangement of the reaction system layout is used to analyze the correlation between substances and the importance of substances to the reaction system.

2. The method of claim 1, wherein the method is based on a node force relationship of a discharge plasma reaction path. Step 3 includes the following specific steps: Step 3.1, the density value and the reaction rate value of each substance species are logarithmically processed, specifically: wherein Density i for a selected time period i average substance number density of the substance, N i for the i node corresponding to the substance, whose attribute N i . D size value of the node corresponding to the substance, i L ij all directed edges pointing to the node N i , j i sum of the reaction rates of the substance participating in the generation j L ij . wid represents the width of the directed edge, L ij . len represents the natural length of the directed edge, L ij . opacity represents the opacity of the directed edge, taking values from 0 to 1;​​​ Step 3.2, the nodes corresponding to each substance species are randomly assigned initial positions and then subjected to force analysis; Two nodes i , j The force between the two nodes includes a repulsive force between the nodes affected by the node size value and the distance between the nodes F c , and an attractive force between the nodes affected by the natural length of the directed edge between the nodes and the current distance between the nodes F h ; Nodes i ,repulsion between nodes j F c and attraction F h are calculated as follows: wherein k c is a repulsion coefficient, N i .D and N j .D are the size values of the nodes i and the node j , Dis ij is the distance between the nodes i and the node j at the current time step, L ij .len is the natural length of the directed edge between the nodes i and the node j . Step 3.3, after two rounds of node-by-node circulation traversal, the resultant force currently suffered by each node is equal to the sum of the repulsion and attraction between it and the other points: The action of the force of the node on the current time step is a damped motion, and the iteration speed is expressed as: wherein V i is the velocity of the previous time step, V i ’ is the velocity of the current time step after force analysis, m i is the mass of the substance; k damp is the damping coefficient, the particle velocity gradually decreases with iteration, and the system tends to be stable. Step 3.4, update the material position after calculating the current time step velocity P i The expression is: The total kinetic energy of the system is calculated by the following formula: When the total kinetic energy of the system is 0, the system stops iteration.

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