Autocatalytic Decomposition Research Articles

Thermal decomposition kinetics and storage life prediction of nitramine propellants with different energetic plasticizers based on model-fitting method

The research on the thermal decomposition of propellant is critical to determining its safe storage life. The thermogravimetry (TG) testing of nitramine propellants plasticized by nitroglycerin (NG), glycidyl azide polymer (GAP), 2,2-dinitropropanol hexanoate (DNPH), and N-butyl-2-nitratoethylnitramine (BuNENA) was performed under non-isothermal circumstances. The thermal decomposition mechanism of propellant was then analyzed using the model-fitting method, and the storage life was predicted based on the mechanism. The results show that when heated to the same mass loss, the temperature of GAP-NC-RDX, BuNENA-NC-RDX, and DNPH-NC-RDX is higher than that of NG-NC-RDX. GAP-NC-RDX, BuNENA-NC-RDX, and DNPH-NC-RDX propellants have superior thermal stability to that of NG-NC-RDX. The kinetic mechanism functions and equations of the propellants were calculated, and multi-step reaction models of the thermal decomposition were built. The major thermal decomposition mechanism of nitramine propellants was discovered to be composite autocatalytic decomposition (Kamal-Sourour equation), which means that the reaction of reactants and the reaction catalyzed by products occur in tandem. The decomposition depth of propellants increases as the temperature rises during the same storage time. The storage lifetimes of GAP-NC-RDX, BuNENA-NC-RDX, DNPH-NC-RDX, and NG-NC-RDX propellants at 288 K are 28.71 years, 24.49 years, 18.34 years, and 16.33 years, respectively. The inclusion of GAP, DNPH, and BuNENA in the formulation improves the storage life of propellant more than NG. This study offers an attractive strategy for analyzing the decomposition mechanism of propellant with a multi-step decomposition reaction and forecasting its storage life.

The stereochemistry of 1,4-dicarboxylic acids on Cu(110): Sergeants & soldiers, surface explosions and chiral reconstructions

Dicarboxylic acids, including tartaric acid, have played a crucial role alongside amino acids in the study of chiral recognition on metal surfaces. Over the past two decades, significant insights into surface stereochemistry have emerged, particularly on Cu(110). This review examines various phenomena observed during the interaction of 1,4-dicarboxylic acids with the Cu(110) surface. We explore diverse aspects such as chiral surface reconstructions, intermolecular chiral recognition, stereoselective autocatalytic decomposition, and chiral symmetry breaking through doping.

Study on the Thermal Decomposition Risk of 3,7-Dinitro-1,3,5,7-tetraazabicyclo[3,3,1]nonane under Different Conditions.

Given its role as a pivotal intermediate in octogen production, the thermal safety of DPT is of paramount importance due to its significant thermal hazard. To assess the potential thermal hazard associated with its decomposition, a nonisothermal DSC experiment and an ARC test were conducted. For the acquisition of more precise thermal decomposition kinetic parameters, the impact of various crucible types on the experimental outcomes was scrutinized. The DSC results indicate that the precise thermal decomposition process of DPT, an autocatalytic decomposition material, can be accurately ascertained by using a high-pressure sealed crucible test. The authentic thermal decomposition process of DPT encompasses two critical reactions: the decomposition of DPT itself and the secondary reaction and decomposition of its byproducts. A robust thermal decomposition kinetic model was established, integrating the findings from the DSC test results. Subsequently, the risk of thermal explosion during DPT storage was simulated by using a kinetic numerical simulation approach.

Advancing high-throughput combinatorial aging studies of hybrid perovskite thin films via precise automated characterization methods and machine learning assisted analysis.

To optimize material stability, automated high-throughput workflows are of increasing interest. However, many of those workflows either employ synthesis techniques not suitable for large-area depositions or are carried out in ambient conditions, which limits the transferability of the results. While combinatorial approaches based on vapour-based depositions are inherently scalable, their potential for controlled stability assessments has yet to be exploited. Based on MAPbI3 thin films as a prototypical system, we demonstrate a combinatorial inert-gas workflow to study intrinsic materials degradation, closely resembling conditions in encapsulated devices. Specifically, we probe the stability of MAPbI3 thin films with varying residual PbI2 content. A comprehensive set of automated characterization techniques is used to investigate the structure and phase constitution of pristine and aged thin films. A custom-designed in situ UV-Vis aging setup is used for real-time photospectroscopy measurements of the material libraries under relevant aging conditions, such as heat or light-bias exposure. These measurements are used to gain insights into the degradation kinetics, which can be linked to intrinsic degradation processes such as autocatalytic decomposition. Despite scattering effects, which complicate the conventional interpretation of in situ UV-Vis results, we demonstrate how a machine learning model trained on the comprehensive characterization data before and after the aging process can link changes in the optical spectra to phase changes during aging. Consequently, this approach does not only enable semi-quantitative comparisons of material stability but also provides detailed insights into the underlying degradation processes which are otherwise mostly reported for investigations on single samples.

CHEMICAL STABILITY OF CELLULOSE NITRATES: REVIEW

The results of the analysis of literature data on updated methods for determining the chemical stability of cellulose nitrates are presented. The relevance of research is due to the need to control the operation and storage of a widespread component of solid rocket fuels and explosive compositions. The criterion for chemical resistance is the value of the decomposition rate or the time dependence of the degree of decomposition of the sample. It is shown that methods for assessing the chemical resistance of cellulose nitrates are based on determining the rate of its thermal decomposition, which is measured by a specific parameter accompanying decomposition. These parameters include weight loss, amount of gaseous decomposition products released, decomposition temperature or thermal effects. Studies are carried out at elevated temperatures and allow you to control the magnitude or rate of change in the parameter that accompanies thermal decomposition. The possibility of using modern analytical methods for evaluating chemical resistance is shown: differential scanning calorimetry, thermogravimetric analysis, chemiluminescent analysis, infrared spectroscopy, high-performance liquid and thin-layer chromatography, gas chromatography, electron paramagnetic resonance, mass spectrometry, X-ray diffraction analysis. The preference for methods of differential scanning calorimetry or differential thermal analysis is substantiated. The results of studies on improving the chemical resistance of cellulose nitrates and compositions based on it with the use of new stabilizers of the aniline series, stabilizers of natural origin with the advantage of the latter on the examples of curcumin and lignins are presented. Due to the insufficient stability of cellulose nitrates, stabilizers added to the formulation of explosive compositions lengthen the induction period of the decomposition of nitro compounds and do not allow the development of the autocatalytic decomposition stage. Methods for determining the chemical stability of cellulose nitrates obtained from alternative sources of raw materials are presented. For citation: Vdovina N.P., Korchagina А.А., Budaev I.А. Chemical stability of cellulose nitrates: Review. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2023. V. 66. N 5. P. 6-20. DOI: 10.6060/ivkkt.20236605.6725.

Simulation of thermal hazards risk in octogen based on non-isothermal DSC data

To evaluate the possible thermal risks associated with the storage of octogen (HMX), non-isothermal differential scanning calorimetry (DSC) experiments were conducted in order to ascertain the kinetic model and parameters governing its thermal decomposition. DSC measurements indicate that HMX underwent a crystal transformation prior to thermal decomposition. A kinetic model for the autocatalytic thermal decomposition process was developed through the analysis of its primary exothermic peaks. Subsequently, numerical simulations were performed using the aforementioned kinetic model to assess the potential thermal explosion hazard of HMX under two distinct storage conditions. The comparison was made between the models of HMX autocatalytic decomposition temperature and thermal explosion critical temperature under two distinct storage conditions. The prediction of the influence of ambient temperature on the critical temperature of thermal explosion is conducted simultaneously. Finally, the thermal hazard parameters of HMX under different package quality are given.

A study on self-shielding effect of CaCO3 in cable pyrolysis using gas product analysis and PSO optimization

This paper investigates the self-shielding mechanism of CaCO3 during the pyrolysis of PVC-CaCO3 based cable. Previous studies have focused on HCl adsorption by CaCO3, neglecting the self-shielding effect. In this paper, thermogravimetric-infrared analyzer, pyrolysis gas chromatography-mass spectrometer and particle swarm optimization (PSO) algorithm are used to investigate the self-shielding mechanism. The results show a three-stage pyrolysis process. In the first stage, CaCO3 weakens the autocatalytic decomposition of PVC by absorbing HCl in the solid phase. The 3rd Avrami Erofeev model was obtained by PSO, representing the production of CaCl2 crystals. The second stage demonstrates self-shielding due to a reduction in solid-phase porosity. CaCO3 encapsulation inhibits the pyrolysis of PVC resulting in macromolecular intermediates. The 3rd order-based model was obtained by PSO, with a lower pyrolysis reaction rate compared to pure PVC. In the third stage, the stability of Cl in the solid phase is weakened at high temperatures, which converts the Cl to the gas phase in the form of chlorinated hydrocarbons, leading to the failure of self-shielding effect of CaCO3. The 2nd order-based model was obtained by PSO, which is considered as a result of the solid phase reactions instead of pyrolysis.

Model identification and classification of autocatalytic decomposition kinetics

Model identification and classification of autocatalytic decomposition kinetics

Reduction in the Thermal Stability of Nitro-Containing Compounds due to Cross-Catalyzed Autocatalytic Decomposition Caused by Nitro-Containing Impurities

Reduction in the Thermal Stability of Nitro-Containing Compounds due to Cross-Catalyzed Autocatalytic Decomposition Caused by Nitro-Containing Impurities

The influence of solvent selection on nitrocellulose-based, perchlorate-free red-and green-light illuminants

ABSTRACT Nitrocellulose (NC) has been used since the late 1800ʹs in numerous energetic formulations; however, the effect of processing agents (solvents, etc.) on performance has not been thoroughly detailed. For illuminate applications, this is critical as spectral purity and dominant wavelength must meet specifications. In this effort, six processing agents (water, ethanol (EtOH), isopropyl alcohol (IPA), ethyl acetate (EtAc), acetone, and tetrahydrofuran (THF)) are evaluated and the effect they have on the NC fibers and subsequent performance is detailed. XRD and FTIR analysis indicates that the choice of processing agent directly affects the molecular integrity of the NC fibers due to the inhibition of NO2 bonds as well as freeing of hydrogen bonds between polymer chains during solubilization. Time-step FTIR analysis indicated that the weak nitrate ester bond (RCH2-ONO2) is targeted when processed in tetrahydrofuran, ethyl acetate, or acetone, and if heavy solvent interaction occurs, can lead to the autocatalytic decomposition of NC, when heat treated at 110°C. Spectral performance is detrimentally impacted as a result of such interactions. While all six processing agents for red-light illuminant formulations met the military requirements (i.e., spectral purity and wavelength), only ethanol and isopropyl alcohol processed formulations met the military required wavelength of 540 ± 20 nm for green-light illuminants. The IPA processed formulations exhibited the best results with spectral purity values of 69.0% and 94.8% for green and red-light illuminants, respectively.

A facile approach of improving the inhibition of arylfulleropyrrolidine on the thermal decomposition of nitrocellulose by enhancing the thermal interaction

A series of aryl[70]fulleropyrrolidine (5a–5b’) were successfully designed and synthesized using Prato reaction. The results of non-isothermal thermal analysis showed that 5a–5b’ can increase the critical explosion temperature of nitrocellulose by 0.8–1.8 K. The results of isothermal experiments proved that 5a–5b’ can prolong the discoloration time of methyl violet test paper of nitrocellulose at 407.65 K and the safe storage life of nitrocellulose at 323.15 K by 87 min and 34.46 years, respectively. The adiabatic accelerated calorimetry analysis showed that 5a–5b’ can reduce the initial autocatalytic decomposition reaction of nitrocellulose. The thermal stability of 5a–5b’ to nitrocellulose was proved to mainly depends on the nitrogen oxide radical scavenging ability of fullerene. Obviously, a small amount of aryl[70]fulleropyrrolidine mixed with aryl[60]fulleropyrrolidine can significantly improve the inhibition of aryl[60]fulleropyrrolidine on the thermal decomposition of nitrocellulose. Subsequently, the feasibility of low-cost and large-scale preparation of arylfulleropyrrolidine stabilizer using fullerene soot as precursor was explored.

Kinetic Investigations of the Electrochemically Assisted Leaching of Metals for the Recycling of Photovoltaics

To describe and predict the leaching of Ag, Cu and Sn from waste photovoltaic modules with an electrochemical-assisted process kinetic investigations were performed. In this process, peroxydisulfate is generated from sulfuric acid to oxidize metals. It was found that under the reaction conditions peroxymonosulfate is formed as well and has a major contribution to the leaching process. For Ag, autocatalytic decomposition of the leaching reagents is determined to be a limiting step while for Sn passivation influences the process. The leaching is modeled for three different reaction types, a batch reaction, the reaction in a static H-cell with continuous generation of S₂O₈2− and a fed-batch reaction with an electrochemical flow cell for the production of peroxydisulfate.

Autocatalytic decomposition of tributyl phosphate in the spent extractant of the PUREX process for safe disposal of radioactive impurities

The possibility of processing the spent extractant of the PUREX-process by thermochemical decomposition of tributyl phosphate (TBP) to hydrocarbons and phosphoric acid was investigated. It was shown that the main condition for the intensive and complete decomposition of TBP is the presence of free phosphoric acid in the system, which ensures the course of the process in an autocatalytic mode. This is observed at a molar ratio of H3PO4: TBP > 2: 1 and can be achieved in the technological process using recycled phosphoric acid. Under these conditions, at a temperature of 190–200 °C, the decomposition of TBP proceeds quantitatively within 5–10 min. It was found that the process proceeds with the formation of butene and a large amount of alkanes and alkenes of various molecular weights, which is caused by secondary processes of polymerization and cyclization of decomposition products catalyzed by excess phosphoric acid. During the decomposition of TBP, radioactive impurities pass into the phosphoric acid phase, which creates the possibility of their neutralization and disposal in the form of phosphate glasses.

Enhanced degradation of tetracycline over FeS-based Fenton-like process: Autocatalytic decomposition of H2O2 and reduction of Fe(III)

This study constructed a FeS-based Fenton-like process to explore the degradation of TTC in the presence of copper ions. The acidic condition of pH 3 was more favorable to the H2O2 decomposition and TTC degradation, and it was slightly enhanced by Cu(II). The production of •OH from H2O2 was revealed through radical scavenging and benzoic acid probe experiments, and the ratio of H2O2 decomposition to •OH production was about 1–1.5, which is comparatively consistent with the theoretical ratio. FeS-based Fenton process was proved to be a homogenous system, the slow release of Fe(II) source and the autocatalytic cycle of Fe(III) to Fe(II) resulting from the reductive species of TTC and dissolved S(-II) improved the production of •OH and the degradation of TTC, which was proved by comparing TTC degradation, TOC removal, H2O2 decomposition and Fe(II) concentration with different iron sources (FeS, Fe(II) and Fe(III)) and external addition of dissolved S(-II). The possible degradation pathways of TTC were subsequently inferred according to the detected products by LC-MS. Understanding these autocatalytic processes is essential to reveal the transformation of redox-active substances in environments and may have potential significance in applying FeS-based Fenton-like process for the treatment of wastewater containing reductive organic matters.

Effect of aniline-fullerene-based stabilizer on thermal decomposition of nitrocellulose

<p indent="0mm">The influence of aniline-fullerene-based stabilizer on the thermal decomposition behavior of nitrocellulose was studied by thermal analysis, isotherm thermogravimetric test, methyl purple paper test, adiabatic accelerated calorimetry and differential scanning calorimetry. The results of the differential thermal analysis showed that the critical temperature of the thermal explosion of nitrocellulose increased <sc>0.36–7.62 °C</sc> with the addition of aniline-fullerene-based stabilizer. The results of the isothermal thermogravimetric analysis are in good agreement with the conclusions of the methyl violet test paper. The results show that an aniline-fullerene-based stabilizer can effectively prolong the discoloration time of methyl violet test paper and the time required to achieve the same weight loss rate of nitrocellulose samples. The results of adiabatic accelerated calorimetry showed that although aniline-fullerene-based stabilizer had little effect on the pressure and temperature at the initial stage of adiabatic decomposition of nitrocellulose, it could effectively reduce the maximum temperature rise rate. The effects of thermal history on the thermal decomposition of nitrocellulose samples are investigated by DSC interruption and re-scanning method. The results showed that the aniline-fullerene-based stabilizer had obvious thermal stability effect on nitrocellulose and inhibited the autocatalytic decomposition of nitrocellulose.

Holistic Case Study on the Explosion of Ammonium Nitrate in Tianjin Port

On 12 August 2015, Tianjin port, Tianjin City, China, a catastrophic explosion of Ruihai International Logistics Co., Ltd. (Tianjin, China) killed 173 and hurt almost 798 people, accompanying a financial loss of almost USD 2 billion. The ignition of the first fire due to the autocatalytic decomposition of nitrocellulose was verified by differential scanning calorimeter (DSC) isothermal tests. A crater with a diameter of 97 m was created by the second explosion. For the second catastrophic explosion, an amount of 577 tons of trinitrotoluene was determined by the average through scaling law, crater inverse analysis and blast effects on structures. The overpressure against distance for consequence analysis was conducted using Baker’s, Sadovski’s and Alonso’s methodologies. A distinctive scenario of “two-successive-sympathetic detonations-following-a-fire” was proposed and discussed. Isothermal time-to-maximum-rate was validated to be approximately 9 days for the nitrocellulose inside the containers with an internal temperature of 60 °C stored at Tianjin port. A fatality radius chosen at the overpressure of 0.6 bar was ascertained to be nearly 410 m from the explosion origin.

Autocatalytic decomposition of energetic materials: interplay of theory and thermal analysis in the study of 5-amino-3,4-dinitropyrazole thermolysis.

A reliable kinetic description of the thermal stability of energetic materials (EM) is very important for safety and storage-related problems. Among other pertinent issues, autocatalysis very often complicates the decomposition kinetics of EM. In the present study, the kinetics and decomposition mechanism of a promising energetic compound, 5-amino-3,4-dinitro-1H-pyrazole (5-ADP) were studied using a set of complementary experimental (e.g., differential scanning calorimetry in the solid state, melt, and solution along with advanced thermokinetic models, accelerating rate calorimetry, and evolved gas analysis) and theoretical techniques (CCSD(T)-F12 and DLPNO-CCSD(T) predictive quantum chemical calculations). The experimental study revealed that the strong acceleration of the decomposition rate of 5-ADP is caused by two factors: the progressive liquefaction of the sample directly observed using in situ optical microscopy, and the autocatalysis by reaction products. For the first time, the processing of the non-isothermal data was performed with a formal Manelis-Dubovitsky kinetic model that accounts for both factors. With the aid of quantum chemical calculations, we have rationalized the autocatalysis present in the formal kinetic models at the molecular level. Theory revealed an unusual primary decomposition channel of 5-ADP, viz., the two subsequent sigmatropic H-shifts in the pyrazole ring followed by the C-NO2 bond scission yielding a pyrazolyl and nitrogen dioxide radicals as simple primary products. Moreover, we found the secondary reactions of the latter radical with the 5-ADP to be kinetically unimportant. On the contrary, the substituted pyrazolyl radical turned out to undergo a facile addition to 5-ADP, followed by a fast exothermic elimination of another ˙NO2 species. We believe the latter process to contribute remarkably to the observed autocatalytic behavior of 5-ADP. Most importantly, the calculations provide detailed mechanistic evidence complementing the thermoanalytical experiment and formal kinetic models.

Study on Autocatalytic Decomposition of Dimethyl Sulfoxide (DMSO) II: Analysis of Intermediate Substances Obtained in the Induction Period and Investigations Regarding Formic Acid

Dimethyl sulfoxide (DMSO) is a good solvent as well as a mild oxidizing agent. Several severe incidents associated with DMSO decomposition have been reported in spite of its wide use. The goal of t...

Chloramphenicol loaded polylactide melt electrospun scaffolds for biomedical applications

Melt electrospinning of polylactide (PLA) loaded with chloramphenicol (CAM) has been performed and characteristics of fibers, physical properties of scaffolds, CAM release behavior, antibacterial properties and biocompatibility have been evaluated. The interest of CAM loaded samples is nowadays enhanced for biomedical applications since this antibiotic has been demonstrated to be efficient for the treatment of cancer. Melt electrospinning has been selected as an ideal preparation process because it avoids the use of toxic solvents which are harmful to the environment and could be problematic for biomedical applications. The electrospinning process rendered fibers with a relatively large diameter (between 20 μm and 40 μm depending on the load) and minimum polymer degradation. Characteristics of melt electrospun scaffolds were also compared with those prepared by solution electrospinning. Differences consisted in a more sustained release and a higher biocompatibility for the melt processed samples. Bactericide effect was evaluated as an evidence of the maintenance of the CAM bioactivity after melt processing at high temperature and the slower release caused by the relatively high diameter of the constitutive fibers. Since pure CAM showed thermal degradation at temperatures relatively close to the PLA melting temperature, a complete analysis of the degradation process of pure CAM as well as of PLA samples loaded with CAM was performed. The Invariant Kinetic Parameters method allowed determining an initial decomposition step that followed an autoaccelatory Avrami model, and then an autocatalytic decomposition reaction took place for conversions higher than 50%. Dispersion in the PLA matrix enhances the thermal stability of the antibiotic, with an onset temperature of degradation that was higher by 16 °C in the melt-electrospun fibers than in the liquid state of pure CAM.

(Invited) Novel Fullerene-Based Stabilizer and Its Behavior during Thermal Decomposition of Nitrocellulose

Propellants are composed of a large number of high-energy components and used widely in rocket and ammunition[ 1,2]. The interaction between components could lead to deterioration of propellants during long-term storage. The main energy components of propellants, such as nitrocellulose and nitroglycerin, decompose slowly while releasing nitrogen oxides[ 3-5]. Traditional stabilizers, such as diphenylamine (DPA), N,N ’-dimethyl-N,N ’-diphenylurea (C2), and N,N'-Dimethyldiphenylurea (AKⅡ), are added into propellants to restrain the autocatalytic decomposition of nitrocellulose[6,7]. However, these traditional stabilizers are consumed immediately at high-temperature or high-pressure environments that do not satisfy the increasing demands of weapon systems for wide temperature range and strict environmental requirement. Moreover, these stabilizers are not environmentally friendly because of the toxicity of the secondary derivatives[ 8,9]. Therefore, it is important to design a new stabilizer that will not deteriorate even under strict conditions. A novel highly functional fullerene derivative, C60-DBTMP, is successfully designed to obtain high performance stabilizers. The thermal stability of this novel fullerene-based stabilizer is investigated by methyl violet test, vacuum stability test, and constant temperature TG were shown in Table 1. The results indicate that C60-DBTMP has good compatibility with nitrocellulose, and the stability is found to be more superiority than other traditional stabilizers (DPA, C2, AKⅡ). Further thermal analysis showed that C60-DBTMP interact with the decomposition products during the thermal decomposition of nitrocellulose, which changed the decomposition mechanism of nitrocellulose at the initial stage of thermal decomposition from self-accelerating catalytic model to non-autocatalytic reaction model. The stabilization mechanism is also investigated in detail, the electron spin resonance (ESR) test showed that the nitroxide radicals scavenging efficiency of C60-DBTMP is 73.39%, and effectively inhibit the acidity change caused by the thermal decomposition of nitrocellulose, which provided a precondition for the thermal stability of nitrocellulose. The results showed that C60-PhO(PhOMe)4 can react with nitric oxide and nitric due to the conjugate structure of the carbon cage and the electron affinity of substituent is considered. The consumption process of C60-DBTMP is found to follow the pseudo-first-order kinetics. Our study demonstrated the potential application of this highly functionalized fullerene derivative as a stabilizer for nitrocellulose and provided a new strategy for designing high-performance stabilizers.Table 1 The test date of vacuum stability test, isothermal TG and methyl violet test Samples S-1 S-2 S-3 S-4 S-5 Stabilizers — DPA C2 AKⅡ C60-DBTMP The time used for weightloss of 1%/min 7.2914.11 15.60 17.10 18.09 The gas volume per unit mass/mL·g−1 4.67 2.79 1.73 1.65 1.19 Time/min 58 75 95 99 129 Storage for 5 h Non-burning and non-exploding Figure 1. The synthesis of C60-DBTMP, and the interruption and re-scanning curves of (a) S-1 and (b) S-5, (c) α-T of S-1 and S-5, (d) Plots of theoretical and experimental y(α), and the ESR spectra of NO-Fe(DETC)2 in different concentrations of (e) AKⅡ and (f) C60-DBTMP. Acknowledgement This work was supported by the financial support received from the Frontier Innovation Project of Military Commission Science and Technology Commission(project no. 19-163-13-ZT-002-004-04), and the China Academy of Engineering Physics (project no. 18zh0080), and the Project of State Key Laboratory of Environment-friendly Energy Materials, Southwest University of Science and Technology (project no. 19fksy04).