HMX/RDX composites were prepared using the solvent-antisolvent alternating method. The morphology and structure of the composites were characterized by optical microscopy, high-performance liquid chromatography (HPLC), Fourier transform infrared spectroscopy (FT-IR), and powder X-ray diffraction (PXRD). The composite exhibited a morphology with HMX as the core and RDX as the coating layer. The HMX existed in the β-phase, and molecular interactions were observed between the two components (a blue shift of 2.06 cm− 1 in the NO2 symmetric stretching vibration peak of HMX and a red shift of 2.06 cm− 1 in the C-H stretching vibration peak of RDX). Thermal analysis revealed synergistic effects in the thermal decomposition process (lower decomposition peak temperature for HMX and higher for RDX), with an apparent activation energy (149.41 kJ/mol) in the first decomposition stage lower than that of the physical mixture and pure RDX component. Concurrently, both the critical thermal detonation temperature (227.74 ℃) and self-accelerating decomposition temperature (213.78 ℃) exceed those of the physical mixture and pure RDX component, thereby demonstrating superior thermal safety. This composite material strikes a balance between energy release efficiency and safety, offering significant application value for weapon systems that pursue higher performance and lower vulnerability. It also provides a novel approach and technical pathway for high-energy explosive formulation design.

The thermal decomposition and metal-driving performance of four HMX/RDX-based PBXs with varying Al/TiH2 ratios (0–8 mass T_SADT ) showed only a marginal reduction, suggesting that macroscopic thermal safety remains manageable. Cylinder tests revealed that within the investigated range, the 4 mass

This study investigates the influence of aluminum powder content on the metal-driving capability and underwater explosion energy of HMX/RDX-based aluminized explosives. Through the preparation of polymer-bonded explosives (PBX) with aluminum content ranging from 0 to 15%, we conducted explosive-driven metal plate test and established JWL-Miller equation of state model incorporating aluminum secondary reactions for underwater explosion simulations using LS-DYNA. Experimental results demonstrated that increasing aluminum content in aluminized explosives resulted in a gradual decline in metal-driving capability, with an 8% reduction observed at 15% aluminum content. Underwater explosion simulations revealed that where the aluminum-oxygen ratio reached 0.15, the shock wave energy achieved 1.846 MJ/kg. Bubble energy showed positive correlation with aluminum content, when the 15% aluminum formulation exhibited prolonged bubble pulsation period (249.6 ms) and expanded bubble radius (107.4 cm). The research validates the effectiveness of the JWL-Miller equation in modeling non-ideal detonation characteristics of aluminized explosives, the impact of aluminum powder on explosive performance is not only reflected in its heat value but also in the timing of energy release. These findings provide critical theoretical guidance for the design of high-energy explosive systems requiring optimized performance.

In this manuscript, the internal crystallization of fused silica crucible samples during the isothermal vacuum annealing (VA) treatment was studied. The results reveal that with the extension of VA time, the internal crystallization of fused silica crucible is different depending on the element composition of raw materials, i.e., quartz sands. Specifically, the fused silica crucible fabricated from quartz sands with an iron concentration of 1.28 ppma presents rapid internal crystallization behavior. At the initial stage of VA treatment, the equivalent crystallization rates in BF and BC layers were as high as 4.35 & micro;m/h and 1.36 & micro;m/h, respectively, but they decreased markedly over time and eventually plateaued at 0.15 & micro;m/h and 0.21 & micro;m/h. Micro-Raman analysis demonstrated that the accelerated crystallization is associated with the formation of second-phase Fe3O4 and FeO nanocrystals near gas bubbles within the fused silica crucible. These Fe3O4 and FeO nanocrystals acted as nucleation sites for cristobalite, facilitating the rapid formation of extensive cristobalite in a short VA treatment period, which may significantly affect the long-term operational stability of the fused silica crucibles. These results reveal the mechanism of the second-phase nanocrystals induced and promoted internal crystallization behavior in fused silica crucibles, which can provide insights into quality evaluation and future optimization of fused silica crucible and quartz sands for Cz-Si growth.

The growing need for next-generation flexible and wearable optoelectronic devices has driven the development of highly sensitive, low-cost flexible photodetectors. Organic-inorganic hybrid perovskite, known for their exceptional optoelectronic properties, are considered ideal candidates for flexible electronics. However, most existing perovskite devices are fabricated on expensive and brittle indium tin oxide (ITO)-coated polymer substrates, which limits their breathability and applicability in wearable systems. In this work, we present a facile and effective solution-based method for fabricating a high-performance perovskite photodetector (PD) on a low-cost, wearable natural silk fabric substrate. Silk fabric offers inherent flexibility, mechanical durability, and biocompatibility, providing an excellent platform for electronic skin applications. Under white light illumination at a 5 V bias, the device demonstrates remarkable performance, with a responsivity of 1.919 A/W and a detectivity of 3.55 × 1012 Jones. It maintains stable operation after 60 bending cycles and even at bending angles approaching 90°, with a rapid response time below 100 ms. This work introduces a practice approach for designing low-cost, highly sensitive, and stable flexible photodetectors, highlighting their broad potential in wearable electronics, smart skin, and low-power optoelectronic systems.

Minimizing platinum-group metal (PGM) usage in anion-exchange membrane fuel cells (AEMFCs) and proton-exchange membrane fuel cells (PEMFCs) is essential for cost reduction. However, achieving power densities exceeding 1 W cm-2 requires high PGM loadings at the anode, particularly in AEMFCs (>0.1 mg cm-2), to sustain hydrogen oxidation reaction (HOR) kinetics. Nickel-based catalysts offer a low-cost alternative but are typically limited by poor activity and oxidative instability. Here, we address these limitations by developing a core-shell nanoreactor comprising Ni nanoparticles (NPs) encapsulated by N-doped graphitic carbon (NC) that is embedded with atomic Ru and Ni species. With an ultralow Ru loading of 1 µg cm-2, anodes using this catalyst deliver peak power densities of 2.36 and 3.26 W cm-2 in AEMFC and PEMFC, respectively, with negligible structure change after 200 h of continuous operation at 1 A cm-2 in both devices. Mechanistic studies in alkaline media reveal a tandem catalytic pathway in which NPs shielded from the electrolyte dissociate H2 to H*, and adjacent atomic metal species enable H* spillover across the NC shell to react with surface-anchored OH*. This work provides a general strategy for designing tandem electrocatalysts for multi-step catalytic processes.

To gain insights into the combustion mechanism of turpentine oil, the oxidation reaction of turpentine was investigated using ReaxFF reactive molecular dynamics simulations. The results revealed that the decomposition of camphene, a component of turpentine, was significantly slow due to the presence of bridged rings in the molecular structure. The oxidation of camphene requires the destruction of six-membered and five-membered rings in sequence. Different oxygen concentrations influenced the initial reactions of turpentine oil. In oxygen-rich conditions, O radicals primarily attacked the CC bonds of turpentine, resulting in the formation of an epoxy structure, C-O-C. In oxygen-poor environments, the thermal decomposition of turpentine is primarily associated with reactions involving C-C bonds. In oxidation, free radicals such as OH, HO2, and H played a significant role in accelerating the reaction rate, with OH exerting the most substantial influence on the reaction involving turpentine oil. The oxidation products of turpentine (C10H16O2 and C10H15O) were unstable at high temperatures and decomposed to yield the earliest intermediate, acetone (C3H6O), with the dehydrogenation reaction mainly assisted by OH radicals. The formation and consumption of intermediate ketene were closely linked to C2 compounds. Furthermore, almost all formaldehyde was consumed by the free radical OH. The activation energy value of alpha-pinene is 80.68 kJ/mol, aligns well with the experimentally estimated activation energy (81.3 +/- 3.1 kJ/mol). This study elucidates the intricate effects of environmental variations on the oxidation process of turpentine oil, providing crucial atomic-level insights for designing environmentally friendly fuels.

ReaxFF molecular dynamics simulations were employed to investigate the behavior of ammonia and ethanol mixed fuel in different conditions, focusing on their combustion reaction mechanisms, intermediates, free radicals, and final product formation at different equivalence ratios. The results reveal that ammonia is primarily consumed by OH free radicals, leading to the formation of the NH2 free radical. NH2 radical undergoes further transformations, forming H2NO, H3NO, HNO, HO2, NO, NO2, HONO, and NH free radicals. The CH3, an intermediate of ethanol, influences the abundance of other free radicals such as H and OH, which also leads to a significant increase in CH2O. In oxygen-rich conditions, OH, HO2, and H2O2 demonstrate higher concentrations compared to oxygen-poor conditions. The NOx species include NO, NO2, and NO3 in rich- and stoichiometricoxygen conditions, whereas in oxygen-poor conditions, only NO is formed. The number of H2O decreases as the proportion of ethanol decreases due to the lack of O atoms, and the amount of H2 continues to increase in the oxygen-poor system. The limited availability of oxygen alters the reaction mechanism, reducing the occurrence of primary form reactions of H2O with the assistance of O, OH, and HO2. Instead, an increasing number of branching chain reactions become prominent at high temperature, leading to the formation of a significant amount of H2.

Aluminum readily undergoes oxidation under ambient conditions, forming a dense Al2O3 surface layer that retards the energy release by oxidation. To enhance the energy release of aluminum powder oxidation, this study focused on the preparation of liquid metal (LM) mediated thermite (LM-Al@oxide) by combining the aluminum powder with the nanosized metal oxides. The thermal properties of thermite and its catalytic effects on the thermal decomposition of dihydroxylammonium 5,5 '-bistetrazole-1,1 '-diolate (TKX-50) were investigated by differential scanning calorimetry (DSC). Specifically, WO3 and Fe2O3 significantly reduced the onset oxidation temperature of aluminum to near its melting point. Upon incorporating LM-Al@oxide composites, both the peak decomposition temperature and activation energy of TKX-50 decreased. Among them, LM-Al@Fe2O3 exhibited optimal catalytic activity for TKX-50 decomposition, reducing its peak decomposition temperature (Tp1) and mean apparent activation energy (Ea) by 24.5 degrees C and 59.0 kJmol-1, respectively, which could be attributed to electron acceptance from TKX-50 through Lewis acid sites in the oxides, thereby lowering the decomposition energy barrier.

Hydrogen can be easily captured by the rare-earth (RE) elements in hydrogen-rich environments, which significantly affect the phase compositions and mechanical performance of Mg-RE based alloys. However, the morphology of RE hydrides and their orientation relationships (ORs) with the Mg matrix have not been well explained. Here, a stable face-centered cubic (FCC) Gd,YH2 hydride was introduced and uniformly distributed in a Mg-15Gd-2.5Y-1Al alloy after hydrogenation treatment at 500 °C and 2 MPa for 40 h. The plate-like Gd,YH2 hydride with six variants was identified to exhibit an OR with the magnesium (Mg) matrix, which is [0001]Mg//[001]Gd,YH2, (101¯0)Mg10.5∘ from (002)Gd,YH2, (12¯10)Mg10.5∘ from (020)Gd,YH2. Further crystallographic matching calculations based on the edge-to-edge matching model suggest that such an OR is energetically favorable and provides the actual interface between the RE hydrides and the Mg matrix during precipitation. Our findings offer new insights into the microstructural regulation of Mg alloys in hydrogenation environments.

To achieve a balance between the high energy performance and the enhanced safety in mixed explosives, two mixed explosive formulations based on CL-20 and NTO were designed, and cellulose acetate butyrate (CAB) and fluoroelastomer (F2603) were selected as binders, respectively. A molecular dynamics simulation of the CL-20/NTO/binder system was conducted, and CL-20/NTO-based PBXs were prepared via the water suspension method. The properties of the CL-20/NTO-based PBX were subsequently investigated. The results indicated that the binding energy (Ebind) and cohesion energy density (CED) between CAB and CL-20/NTO were superior to the interactions observed between F2603 and the explosives. Furthermore, the morphology of powder particles in the CL-20/NTO-based PBX, utilizing both binder systems, yielded particles that were more intact, exhibiting ellipsoidal or globular shapes with uniform sizes. The activation energy of the PBXs prepared with the CAB binder system increased by 56.25 kJmol(-)(1) compared to that of CL-20, and were 6.11 kJmol(-)(1) higher than that prepared with the F2603 binder system, indicating the improved thermal stability of the CAB PBX. With the same composition of CL-20 and NTO, the CAB binder system demonstrated a higher detonation velocity, thus providing better energy performance. Slow cook-off test of the PBX using the CAB system at a heating rate of 2 K/min exhibited a combustion response level, whereas the F2603 system displayed the explosion behavior, suggesting that the CAB PBX system possesses superior insensitivity. Additionally, the influence of varying pressure and temperature on the formability of CL-20/NTO-based PBX under both binder systems was studied to enhance data support for the preparation of high-energy, blunt explosives.

Due to the inherently low thermal conductivity of both explosives and binders, polymer-bonded explosives (PBXs) generally exhibit poor thermal conductivity. As a result, during external temperature fluctuations, internal temperature gradients and thermal stresses are prone to develop, thereby increasing the risk of structural damage. In this study, a bioinspired composite thermal conductive layer was facilely fabricated by in situ polymerizing phase-transitioned lysozyme (PTL) on the surface of graphene (Gr), forming a Gr@PTL composite layer. Subsequently, the Gr@PTL composite was incorporated into PBX system to enhance its thermal performance. The successful coating of PTL onto the graphene nanosheets was verified through characterization methods including SEM and XPS. Thermal analyses revealed that the composite thermal conductive layer not only improved the thermal stability but also increased the thermal diffusivity of the PBX by 52.94% and its thermal conductivity by 44.44%. Furthermore, the composite layer effectively reduced the sensitivity of energetic crystals. Consequently, the proposed biomimetic composite thermal conductive layer offers a novel strategy for enhancing the operational safety of energetic materials and the thermal performance of PBXs.

Polymer-bonded explosives (PBX) based on HMX offer exceptional detonation performance but are limited by high costs. This study investigates the feasibility of reducing costs by partially substituting HMX with RDX while maintaining energy output. Four HMX-based PBXs with RDX doping ratios of 0%, 8.3%, 16.6%, and 24.9% were prepared and characterized. Results indicate that RDX incorporation has minimal impact on the formulation's microstructure. However, at 24.9% RDX content, Differential Scanning Calorimetry (DSC) revealed a 6 degrees C decrease in decomposition peak temperature and a 15 kJ/mol drop in activation energy. Cylinder tests showed only a marginal reduction in Gurney energy (2.99 mmmu s(-)(1) vs. 2.97 mmmu s(-)(1)). Validated by explosive driving tests and multi-physics simulations across various media, the velocity differences remain negligible. These findings confirm that partially replacing HMX with RDX is a viable, cost-effective strategy for PBX formulations without significantly compromising performance.

Plasticizer migration is a significant issue in the utilization of polymer materials. For cellulose derivatives substituted with two or more different groups, such as cellulose acetate butyrate (CAB), the varying proportions of acetyl and butyryl groups lead to different chemical structures, which influence the plasticizer migration properties. This paper investigates the effects of the butyryl substitution degree on plasticizer migration properties through experimental testing and molecular dynamics simulations. Results from experiments and simulations indicate that as the temperature increases, the plasticizer in the mixed system is more likely to migrate with the increase in CAB butyryl substitution. Microscopic and mesoscopic mechanism studies reveal that the strength of intermolecular forces between the plasticizer and CAB is not the primary reason for the differences in plasticizer migration. The main reasons could be attributed to the reduction in steric hindrance effect and plasticizer migration pathway as the degree of butyryl substitution increases.

This case study explored the mechanisms influencing anoxic/oxic processes in 100 ton/h treatment system of coal gasification gray water (CGGW). It was experiencing "spiked" NH+4 -N and COD, and unstable operation. To identify the issues and find a solution, sideline simulation experiments were commenced by installing 600 times miniaturized bioreactor of 14 m3 with 70 L/h inlet flow rate. Data during the start-up revealed that the period of sludge acclimation (24 days) and stabilization (10 days), 30 % reflux from oxic- to anoxic-pond, and 0.8-1.2 mg L- 1 DO maintained in the oxic-pond favored nitrification. However, it could not sustain denitrification without adding organic carbon to the anoxic-pond. Therefore, two co-substrates (glucose and methanol) were supplemented separately to study metabolic response of aerobic/anaerobic ammonia-oxidizing bacteria (AerAOB/ AnAOB), and denitrifying bacteria (DNB). Glucose increased the COD, NH+4 -N and NO- 2 in both ponds, reflecting hampered partial denitrification and anammox in anoxic-pond by heterotrophic non-function bacteria over DNB, and intolerance of AOB to organic carbon. Glucose also declined NO- 3 in oxic-pond by depriving AerAOB and AnAOB. Methanol addition (15 L) quickly enhanced denitrification; however, later NO- 2 and NO- 3 in oxic-pond declined, and NH+4 -N spiked. By reducing methanol dose (7 L), effluent COD and NH+4 -N met the discharge standard again. It indicated that overdosed methanol exceeded DNB usage, caused COD increase, inhibited the growth and activity of AnAOB, and was carried to the oxic-pond, where it restricted the AOB's growth and ammonium oxidation/nitrification. On this basis, methanol dosage in the main plant was reduced from 2400 to 1540 kg/day, which reduced COD and NH+4 -N to meet the standard, and achieved the plant's operational stability. These findings conceptualized the anoxic/oxic CGGW treatment model "synergistic partial anammoxnitrification and denitrification-anammox (SPANDA)" regulated by lower methanol dosage.

The monitoring and analysis of chemical reaction processes are essential for improving reaction efficiency, optimizing production conditions, and ensuring product quality. Infrared spectroscopy, as a non-destructive and real-time analytical technique, provides dynamic insights into the evolution of component concentrations within reaction systems. In this study, the monitoring software was developed by combining infrared spectra with multivariate curve resolution-alternating least squares (MCR-ALS) to dynamically track complex chemical reactions. Using the synthesis of 3,7-dinitro-1,3,5,7-tetraazabicyclo[3.3.1]nonane (DPT) as a case study, the concentration profiles and pure spectra of the reactant hexamethylenetetramine (HMTA), the esterified intermediate (3-acetoxymethyl-7-nitro-1,3,5,7-tetraazabicyclo[3.3.1]nonane), and the product (DPT) were successfully resolved. Computed infrared spectra for HMTA and DPT showed high similarity to measured spectra, with similarity scores of 0.937 and 0.915, respectively. MCR-ALS analysis allowed deduction of the intermediate structure and proposal of the DPT synthesis mechanism, consistent with prior reports and validating the accuracy of the method. Kinetic modeling revealed a three-stage reaction pathway following an A -* B -* C model, where A, B, and C correspond to HMTA, the esterified intermediate, and DPT, respectively. The process follows firstorder kinetics with rate constants of k1 = 0.095 min-1 and k2 = 0.00419 min-1. Overall, this study demonstrates the potential of the developed software for monitoring complex reaction systems, supporting process optimization, quality control, and risk management.

ReaxFF-MD were employed to study the thermal decomposition of the composite structure of CL-20 with graphene and its derivatives. The analysis of the consumption rate of CL-20 shows that the catalytic activity of graphene and its derivatives is related to density and temperature. The increase in reaction temperature accelerates the thermal decomposition of CL-20, while the increase of density inhibits the initial decomposition. The addition of graphene did not alter the main decomposition pathway of CL-20. The main decomposition products of CL-20 are N-2, H2O, and CO2, among which N-2 is the most abundant and its generation rate depends on the density. The order of N-2 formation rate at different densities is N-N2 (0.8 V-0) > N-N2 (0.9 V-0) > N-N2 (V-0). The formation of sp(3) carbon atoms at the peaks and valleys on graphene have a significant catalytic effect. The increase in temperature and compression density led to the appearance of additional pores on the wrinkled GR, GR(p), and G-OH sheets, forming dangling sp(2) carbon atoms. The formation of these defect structures enhanced the adsorption of intermediates and free radicals on graphene sheets and accelerated the interatomic exchange between active groups. However, atomic exchange hardly damages the integrity of the graphene layer.

The adiabatic decomposition of a reaction mixture prepared in DPT using the acetic anhydride method was analyzed using an Accelerating Rate Calorimeter (ARC) to determine the thermal decomposition characteristics and kinetic parameters of the reaction solution at different reaction times. The adiabatic decomposition kinetics were modeled using TSS software, and the corresponding kinetic parameters were derived. Subsequently, a numerical simulation was employed to predict the critical ambient temperature of the reaction liquid in the reactor in case of cooling failure. The results indicated that the CT value was lowest at a feeding time of 10 minutes, highest at a holding time of 15 minutes, and closest to the cooling temperature of the reactor at a feeding time of 30 minutes.