Abstract:To supplement the scarce basic solubility data of cyclotetramethylene tetranitramine （HMX） in dimethyl sulfoxide （DMSO）-alcohol mixed solvent systems and solve the technical bottleneck restricting the optimization of HMX crystallization process， the solubility of HMX in three binary mixed solvents of DMSO-methanol， DMSO-ethanol and DMSO-n-propanol was measured via the static method within the temperature range of 293.15-343.15 K. The experimental solubility data were correlated and fitted by the Apelblat model， Jouyban-Acree model and NRTL model， and the dissolution thermodynamic properties of HMX were further calculated and analyzed based on the NRTL model. The results show that the solubility of HMX in the three mixed solvent systems increases significantly with the rise of temperature and DMSO mole concentration. The Apelblat model exhibits the optimal correlation performance for the solubility data of the systems， with the average relative deviation （ARD） less than 5% and the root-mean-square deviation （RMSD） less than 0.11%， which is superior to the other two models. Thermodynamic analysis indicates that the dissolution process of HMX in all three DMSO-alcohol mixed solvent systems is endothermic， entropy-driven and spontaneous.

Abstract:To investigate the effect of α-HMX content on the thermal safety of RDX produced via the acetic anhydride method， and thus addressing a gap in the existing research， five RDX samples （R1-R5） were prepared with α-HMX contents of 0， 9.50%， 12.41%， 17.00%， and 21.68%， respectively. The crystal form of HMX was identified using infrared spectroscopy and scanning electron microscopy. By employing differential scanning calorimetry （DSC） combined with the Ozawa method， Kissinger method， and modelling techniques， we systematically analyzed the thermal decomposition characteristics， kinetic patterns， and storage/transport safety parameters of the samples. Findings indicate that α-HMX reduces the activation energy and decomposition peak temperature of RDX. When the α-HMX content is ≤17.00%， compatibility remains satisfactory and thermal stability is maintained. However， when the α-HMX content reaches 21.68%， the apparent activation energy drastically decreases to 137.29 kJ·mol^-1， compatibility deteriorates， and the self-accelerating decomposition temperature （SADT） drops to approximately 108 ℃， which markedly increases the risk of thermal detonation. Both the RDX and RDX/α-HMX systems follow a three-step sequential reaction model： ‘autocatalysis → N-stage → autocatalysis’. The Ozawa and Kissinger methods can provide initial parameter values for kinetic model fitting. For storage and transportation， there were no significant differences in the SADT among the groups at load capacities of 10， 20 kg and 50 kg. The kinetic model and critical safety parameters established herein provide essential technical support for production control and storage/transport safety in acetic anhydride-based RDX manufacturing， and confirm that the α-HMX content in the product must be maintained below 17.00%.

Abstract:To investigate the reaction-growth behavior of propellant and polymer-bonded explosive （PBX） under mass-inertial confinement following non-shock ignition， a thick-walled cylinder/mass-block experimental configuration was developed. Laser ignition was used to initiate the reaction. Multiple photonic Doppler velocimetry （PDV） probes were arranged to synchronously measure the radial expansion velocity of the cylinder and the axial velocity of the top surface of the mass block. High-speed imaging was also employed. Post-test residue recovery and examination were further conducted to comparatively analyze the reaction-evolution process. The results show that mass-inertial confinement intensifies the early-stage pressurization during reaction growth. Under identical confinement conditions， however， the type of energetic material governs the reaction-growth characteristics and reaction violence. In the propellant tests， the early-stage pressurization is dominated by mass-inertial confinement. The system response is characterized primarily by axial motion of the mass block， and no yielding deformation occurs in the thick-walled cylinder. The peak reaction pressure remains below 50 MPa， the reacted fraction is less than 1%， and nearly all of the propellant is recovered， indicating a burning event. In the PBX tests， the early-stage pressurization is jointly governed by mass-inertial confinement and structural confinement. The cylinder undergoes yielding and radial expansion， while the mass block exhibits axial motion accompanied by local upsetting deformation. The peak reaction pressure reaches 2 GPa， the reacted fraction exceeds 50%， and no explosive residue is recovered， indicating a violent explosive reaction.

Abstract:To improve the rock failure effects in open-pit deep hole blasting， a hole-inner layered column charge was designed. Firstly， small charge quantity blasting experiments under different charge forms were conducted to obtain the blasting failure process and final failure morphology of rock specimens. Then， the DEM-PBM （Discrete Element Method - Particle Blast Method） coupled simulation technique was used to numerically simulate the blasting process of various charges， further visually revealing the blasting failure characteristics of rock specimens. Finally， field tests were conducted to investigate the practical application effects of this charge form. The results showed that under the blasting action of hole-inner continuous column charge， only one blasting crack occurs in the 1/4 section at the top of the rock specimen， dividing it into two parts. The horizontal moving velocity of the rock fragment is 2.0 m·s^-1， and a large rock fragment with a diameter of 9.0 cm is produced after blasting. Under the the blasting action of hole-inner layered column charge， multiple blasting cracks occur in the 1/4 section at the top of the rock specimen， dividing it into several fragments. The horizontal moving velocity of the rock fragment increase into 7.0 m·s^-1， and no large fragments with a diameter of more than 5 cm is formed. Numerical simulations visualized the blasting process of rock specimens， and verified that the hole-inner layered column charge could eliminate large fragments with a size exceeding 5.0 cm. In practical open-pit deep hole bench blasting， the use of hole-inner layered column charge could significantly enhance the failure degree of rock mass at the top of bench， reducing the large rock fragment rate from 48.1% to 5.6%， which proved its engineering practicality in improving rock failure effects of deep hole blasting.

Abstract:To address the treatment dilemma of HMX production wastewater characterized by complex components， high toxicity and poor biodegradability， a heterogeneous Fenton catalyst Fe_2.5Mo/AC loaded with Fe/Mo bimetals was prepared via the impregnation-high temperature carbonization method using chitosan-modified activated carbon （AC） as the carrier. The amino functional groups of chitosan were adopted to anchor metal active sites and inhibit the agglomeration of active components； meanwhile， Mo was introduced to construct a Fe-Mo bimetallic synergistic system， which accelerated the Fe³⁺/Fe²⁺ redox cycle and improved the generation efficiency of ·OH. Results showed that a stable Fe-Mo-O/N composite structure was formed inside the catalyst with uniformly distributed active sites. Batch experimental results indicated that the catalytic system was applicable to a wide pH range of 2.09-7.15. The removal efficiencies of HMX and COD reached 83.1% and 44.5%， respectively， and the B/C ratio of wastewater was increased from 0.011 to 0.367， presenting an obvious improvement in biodegradability. The optimal reaction conditions were determined as catalyst dosage of 5 g·L^-1， H₂O₂ concentration of 300 mM and reaction temperature of 25 ℃. Radical quenching experiments combined with electron paramagnetic resonance （EPR） tests verified that ·OH， ¹O₂ and ·O₂^- jointly participated in the degradation of HMX. After seven cycles of reuse， the HMX removal rate remained above 70% with extremely low metal leaching capacity. During 14 h continuous operation in the fixed bed reactor， the removal efficiencies of COD and HMX were stably maintained above 70% and 60%， respectively.

Abstract:To improve and optimize the description of high-temperature and high-pressure behaviors of complex nanostructured carbon cluster products in explosives such as triaminotrinitrobenzene （TATB） and benzotrifuroxan （BTF）， and effectively enhance the prediction accuracy of the detonation thermodynamic calculation program VPL for detonation parameters of the above explosives. Based on the physical model established by molecular dynamics research on carbon condensation， this study introduces a carbon phase fraction algorithm. Combined with the single-phase equations of state （EOS） of graphite and diamond， a novel equation of state named NDGP （Nano-Diamond-Graphite-Peng） is established to characterize diamond-graphite core-shell composite nanostructured carbon clusters. Meanwhile， by modifying the single-phase EOS of graphite， a new EOS denoted as NOCP （Nano-Onion-Carbon-Peng） is developed for describing onion-like nanocarbon clusters formed under high detonation temperature conditions. NDGP and NOCP are adopted to calculate the detonation velocity， detonation pressure， overdriven detonation Hugoniot relations and work capacity of detonation products for TATB （including TATB-based composite explosives） and BTF， respectively. By comparing the calculated results with the data obtained from two classic condensed carbon EOS （Fried and Cowan-Fickett models）， it is verified that the two newly developed EOS for condensed carbon products can achieve more accurate prediction of C-J detonation parameters of TATB and BTF. Specifically， the prediction accuracy of TATB detonation velocity is generally increased by 1.5%-2.5%， and more accurate evaluation results can also be obtained for product work capacity and overdriven detonation Hugoniot relations. In addition， an EOS for characterizing the thermodynamic properties of low-density disordered carbon products is introduced. The detonation velocity-density correlation of the typical primary explosive lead trinitroresorcinate （LTNR） is systematically calculated. Compared with the Fried and Cowan-Fickett EOS， the overall prediction accuracy is improved by 3%-7%.

Abstract:Tubular channel reactors possess superior advantages of efficient mass and heat transfer， which lays a solid foundation for the industrial transformation of mixing-controlled strongly exothermic reactions from traditional batch processes to continuous-flow processes. In this work， the synthesis of 3-amino-4-aminoximinofurazan （AAOF） was taken as the research subject. First， reaction calorimetry experiments were carried out to acquire the fundamental heat release data during the reaction process. Combined with material balance and heat balance calculations， the characteristic parameters of the exothermic model inside the tubular channel reactor were determined， and a coupled heat transfer-exothermic model was subsequently established. A numerical solution method was employed to simulate the jacket heat transfer capacity， heat transfer rate， and heat exchange efficiency of the heat transfer medium. On the basis of the simulation results， the thermal safety risks existing in the continuous-flow reaction process were analyzed， and a targeted heat exchange control scheme was proposed accordingly.The results reveal that under the fixed structural parameters of the tubular channel reactor （inner diameter of 0.01 m， tube length of 5 m） and AAOF production capacity of 2 kg·h^-1， when heat conduction oil is used as the heat exchange medium in the cocurrent flow mode， its mass flow rate exerts a remarkable influence on process thermal safety. When the mass flow rate is lower than 0.1 kg·h^-1， the outlet temperature of the tubular reactor exceeds 120 ℃， approaching the initial decomposition temperature of AAOF reaction solution （121.7 ℃）， which is liable to induce heat accumulation and further reaction runaway. The optimal heat removal performance is achieved at a mass flow rate range of 2-3.5 kg·h^-1. When the mass flow rate exceeds 4.5 kg·h^-1， the system temperature drops below 100 ℃ and cannot satisfy the required process temperature conditions. The optimal mass flow rate range of the heat transfer medium is finally determined to be 2-3.5 kg·h^-1. This study provides basic fundamental data and parametric guidance for the process safety design and stable long-term operation of AAOF preparation in tubular channel reactors.

Abstract:To address the challenges of complex components， difficult identification， and low intelligence of traditional detection methods for mixed explosives， two energetic material mixtures of m-dinitrobenzene/potassium nitrate and p-nitroaniline/ammonium nitrate were selected as research objects. A sequential detection strategy combining infrared preliminary screening and Raman confirmation was adopted. Combined with convolutional neural network （CNN）-based deep learning intelligent spectral image processing and recognition method， the spectral response characteristics of the samples in powder and flake forms were investigated. Meanwhile， the effects of component content and physical morphology on detection results were explored. The results indicate that for powdered energetic material samples， infrared spectroscopy can preliminarily identify the presence of m-dinitrobenzene and p-nitroaniline via characteristic peaks at specific wavenumbers， whereas it is difficult to independently distinguish inorganic oxidants such as potassium nitrate and ammonium nitrate. Raman spectroscopy can effectively characterize the nitrobenzene functional group structures of both powdered and flake samples. It can not only realize the qualitative identification of organic energetic components， but also detect characteristic signals unresponsive to infrared spectroscopy， thereby achieving accurate full-component identification of mixed explosives. Although instrumental parameters， excitation wavelength and sample morphology cause spectral peak shift and intensity fluctuation， the positions of core characteristic peaks and overall spectral profiles maintain favorable stability， which can provide a reliable spectral basis for the classification and identification of mixtures. The average recognition accuracy of the deep learning-based intelligent recognition model reaches 96.54% and 96.29% for mid-infrared and Raman spectral samples， respectively， with the average recognition time of a single sample being 0.044 s and 0.042 s.

Abstract:Energy level is the fundamental property of energetic compounds and is one of the core criterion for determining whether an energetic compound has application potential. Experimental determination of detonation parameters is the basic method to evaluate energy level. However， due to the large dosage required and the poor reproducibility of the result， it is impossible to directly provide the theoretical maximum energy， which fails to meet the needs of new compound development. Non-experimental methods， including detonation equations of state， semi-empirical formulas and machine learning models， can predict detonation parameters via basic physicochemical properties or even only molecular structures. These methods become effective approaches for designing and screening new energetic compounds. This study systematically reviews these non-experimental evaluation methods. It summarizes and analyzes their basic principles， applicable conditions， advantages and disadvantages. Equations of state are theoretically rigorous and reliable but need precise physicochemical properties as input. Semi-empirical formulas are the most convenient to apply but lack sufficient accuracy and still require physicochemical properties as input. Machine learning models can predict detonation parameters only by molecular structures but have poor generalization performance. Overall， all existing methods are established based on available experimental data. Their weak data foundation limits extrapolation capability for unknown compounds， failing to meet the requirements for the design and screening of novel energetic compounds. Herein， we propose physics-mechanism-constrained hybrid models and dimensional expansion of energy evaluation parameters， to overcome the experimental data dependence of existing methods and improve their prediction accuracy and generalizability.

Abstract:Gunshot residue （GSR） is a trace particle formed during the firing of a bullets. As an important research subject in forensic science， it plays a key role in the investigation of gun-related cases. Currently， conventional GSR detection mainly relies on large laboratory instruments. However， due to the complexity of sample pretreatment and the longthy submission process， it is difficult to provide analysis results quickly， thereby affecting the decision-making efficiency of on-site investigation work. In recent years， GSR on-site rapid detection technology has received widespread attention due to its simple operation， low cost， and portability. This type of technology can be directly implemented at the crime scene without relying on large precison instruments ， and can quickly output detection results. It is suitable for the preliminary screening of GSR and can also be used as the final confirmation detection method， and has become a research hotspot in this field. Therefore， a systematic review of the research progress on-site rapid detection technology for GSR is conducted， focusing on introducing five categories of methods： colorimetric methods， spectroscopic methods， mass spectrometry methods， electrochemical methods， and fluorescent labeling methods. Their advantages and limitations are thoroughly analyzed， and they are compared with the practical applications of laboratory detection technology. Finally， future research development directions are proposed， aiming to provide theoretical basis and methodological references for on-site technicians in actual detection work.