Simulations of Femtosecond-Laser Near-Field Ablation Using Nanosphere under Dynamic Excitation.

Femtosecond lasers have garnered widespread attention owing to their subdiffraction processing capabilities. However, their intricate natures, involving intrapulse feedbacks between transient material excitation and laser propagation, often present significant challenges for near-field ablation predictions and simulations. To address these challenges, the current study introduces an improved finite-difference time-domain method (FDTD)-plasma model (plasma)-two-temperature model (TTM) framework for simulating the ablation processes of various nanospheres on diverse substrates, particularly in scenarios wherein dynamic and heterogeneous excitations significantly influence optical-field distributions. Initially, FDTD simulations of a single Au nanosphere on a Si substrate reveal that, with transitions in the excitation states of the substrate, the field-intensity distribution transforms from a profile with a single central peak to a bimodal structure, consistent with experimental reports. Subsequently, simulations of a polystyrene nanosphere array on a SiO2 substrate reveal that different excitation states of the nanospheres yield two distinct modes, namely near-field enhancement and masking. These modes cannot be adequately modeled in the FDTD simulations. Our combined model also considers the intrapulse feedback between the electromagnetic-field distribution resulting from near-field effects and material excitations. Furthermore, the model can quantitatively analyze subsequent electron-phonon coupling and material removal processes resulting from thermal-phase transitions. Consequently, our model facilitates predictions of the femtosecond-laser ablation of single nanospheres or nanosphere arrays with varying sizes and materials placed on substrates subjected to near-field effects.

Quasi-Planar Core based Spiro-Type Hole-Transporting Material for Dopant-Free Perovskite Solar Cells.

Hole-transporting materials (HTMs) are crucial for obtaining the stability and high efficiency of perovskite solar cells (PSCs). However, the current state-of-the-art n-i-p PSCs relied on the use of 2,2',7,7'-tetrakis(N,N-di-p-methoxyphenylamine)-9,9'-spirobifluorene (spiro-OMeTAD) exhibit inferior intrinsic and ambient stability due to the p-dopant and hydrophilic Li-TFSI additive. In this study, a new spiro-type HTM with a critical quasi-planar core (Z-W-03) is developed to improve both the thermal and ambient stability of PSCs. The results suggest that the planar carbazole structure effectively passivates the trap states compared to the triphenylamine with a propeller-like conformation in spiro-OMeTAD. This passivation effect leads to the shallower trap states when the quasi-planar HTMs interact with the Pb-dimer. Consequently, the device using Z-W-03 achieves a higher Voc of 1.178 V compared to the spiro-OMeTAD's 1.155 V, resulting in an enhanced efficiency of 24.02%. In addition, the double-column π-π stacking of Z-W-03 results in high hole mobility (~10-4 cm2 V-1 s-1) even without p-dopant. Moreover, when the surface interface is modified, the undoped Z-W-03 device can achieve an efficiency of nearly 23%. Compared to the PSCs using spiro-OMeTAD, those with Z-W-03 exhibit enhanced stability under N2 and ambient conditions.

Identification and Comprehensive Analysis of circRNA-miRNA-mRNA Regulatory Networks in A2780 Cells Treated with Resveratrol.

Ovarian cancer (OC) is one of the most commonplace gynecological malignancies. This study explored the effects of resveratrol (RES) on OC cell proliferation and apoptosis. Proliferation activity was measured for A2780 cells treated with RES for 24 h and 48 h at concentrations of 0, 10, 25, 50, 75, 100, 150, 200, and 300 µM. RNA sequencing (RNA-seq) was performed to analyze the circular RNA (circRNA), microRNA (miRNA), and messenger RNA (mRNA) expression spectrum. The differentially expressed genes included 460 circRNAs, 1988 miRNAs, and 1671 mRNAs, and they were subjected to analyses including Gene Ontology, the Kyoto Encyclopedia of Genes and Genomes (KEGG), and Reactome enrichment. We selected signaling pathways enriched in the cell processes by mRNA KEGG, comprehensively analyzed the circRNA-miRNA-mRNA regulatory network, and verified several miRNAs expressed in the regulatory network diagram using the quantitative real-time polymerase chain reaction. The data showed that the cell proliferation of A2780 cells treated with RES for 24 h or 48 h decreased with increasing concentrations of RES. The circRNA-miRNA-mRNA regulatory network that we constructed provides new insights into the ability of RES to inhibit cell proliferation and promote apoptosis in A2780 cells.

Thermal curing mechanisms and cross-linking network structure of a novel silicon-containing arylacetylene resin with 2,7-diethynylnaphthalene unit.

Silicon-containing arylacetylene resin and its composites have attracted great interest as emerging heat-resistant materials, but their curing mechanisms and products are still elusive. In this work, the influences of the terminal and inner acetylenes on the curing mechanisms of silicon-containing arylacetylene resin with 2,7-diethynylnaphthalene were first identified by density functional theory. Two reaction pathways were proposed and their products include polyenes, anthracene dimers, and benzene trimers. To gain a distinct observation of the cross-linking process, molecular dynamics simulations were used to construct a cross-linking polymerization model. The effects of the temperature on the cured structure were investigated by analyzing the characteristics of the cross-linked network. As expected, higher curing temperature will make the larger proportion of polyene chain and aromatic ring in the terminal alkyne-terminal alkyne route, meanwhile, for the inner alkyne-inner alkyne route, the short chains and a small amount of aromatic rings are major productions. Overall, our cross-linking method may provide an unique guidance for studying the cured structure of other thermosetting resins.

Novel metalloporphyrin covalently functionalized polyphosphazene nanotubes for boosting the hydrogen evolution reaction.

Herein, we demonstrate the first example of a novel electrocatalytic hybrid system (CoTPP-PZSNT) with a push-pull motif to boost hydrogen evolution reaction (HER) activity. CoTPP-PZSNT exhibits an efficient HER activity, with overpotentials of 157 and 109 mV at 10 mA cm-2 in 1.0 M KOH and 0.5 M H2SO4 solutions, respectively. The HER performance of CoTPP-PZSNT outperforms many previously reported HER catalysts, due to efficient charge transfer between each component.

Bayesian decision based fusion algorithm for remote sensing images.

Remote sensing image fusion is dedicated to obtain a high-resolution multispectral (HRMS) image without spatial or spectral distortion compared to the single source image. In this paper, a novel fusion algorithm based on Bayesian estimation for remote sensing images is proposed from the new perspective of risk decisions. In this study, an observation model based on Bayesian estimation for remote sensing image fusion is constructed. Three categories of probabilities including prior, conditional and posterior probabilities are calculated after an intensity-hue-saturation (IHS) transformation is applied to the original low-resolution MS image. To obtain the desired HRMS image, with the corrected posterior probability, a fusion rule based on Bayesian decisions is designed to estimate which pixels to select from the panchromatic (PAN) image and the intensity component of the MS image. The selected pixels constitute a new component that will participate in an IHS inverse transformation to yield the fused image. Extensive experiments were performed on the Pleiades, WorldView-3, and IKONOS datasets, and the results demonstrate the effectiveness of the proposed method.

Recent progress in the advanced strategies, rational design, and engineering of electrocatalysts for nitrate reduction toward ammonia.

Ammonia is a valuable feedstock for most chemicals, pharmaceuticals, and fertilizer products. It is a promising carbon-free energy source. Under severe experimental circumstances (high temperature and high pressure), ammonia is manufactured industrially using the standard Haber-Bosch process. This process uses a lot of energy and emits a huge amount of CO2 into the environment. One method that is seen to be promising and could eventually replace the Haber-Bosch process is the electrocatalytic production of ammonia. However, in ambient conditions, the cleavage of the nitrogen molecule is exceedingly difficult. As a result, the yield of ammonia remains modest and the study's scope is still restricted to the lab. When the catalytic performance is significantly increased, nitrate and nitrite contaminations in water systems can be effectively removed and simultaneously transformed into energy sources if nitrites or nitrates are employed as nitrogen sources instead of nitrogen gas. This may become a new substitute for the synthesis of ammonia, but nitrate and nitrite reduction are not getting enough attention. In this review, we discuss the performance of the electrocatalytic nitrate reduction reaction, which includes cycling stability, reactivity, selectivity, and faradaic efficiency. Following this summary, we look into the crucial elements, the rate-determining step, and the reaction mechanisms that govern the performance of the nitrate reduction reaction. In order to support the practical use of the electrocatalytic nitrate reduction reaction, we finally provided a summary of the challenges and future directions guiding the design of efficient catalyst and reaction systems.

An empirical study of the flag rugby game programme to promote gross motor skills and physical fitness in 5-6 year old preschool children.

In order to investigate the effects of a flag rugby game programs on the development of gross motor skills and physical fitness in 5-6 year old preschool children. An overall random sampling method was adopted to select 56 preschoolers aged 5-6 years from class A and class B,class A was the ExG (28) implemented a flag rugby games intervention program,and class B was the ConG (28) implemented a regular physical education program,with a 12-week intervention period.The content and requirements of the experimental intervention program were determined through a systematic analysis method, and the subjects' gross motor skills level was tested using the TGMD-3, and their physical fitness level was measured using China's fifth national physical fitness monitoring of early childhood (3-6 years) component.Experimental data were statistically analyzed using independent samples t-test, paired samples t-test, and repeated measures ANOVA test.After 12 weeks of practice, 1）We found that the ExG outperformed the ConG in Skip,One hand stationary dribble, Overhand throw, Underhand throw, Forehand strike of self-bounced,Kick a stationary ball, Total object control subject score, Total gross motor score test results with significant differences (p < 0.05).The ExG differed significantly (p < 0.01) in Grip strength, Stand long jump,Sit forward bend, Continuous jump on both feet,15 m obstacle run,Walk the balance beam, while the ConG differed significantly (p < 0.05) only in Continuous jump on both feet,15 m obstacle run and Stand long jump.2）We also found gender differences in gross motor skills and Physical fitness test results, this difference is manifested in boys outperformed girls in Total object control subject Score, Grip strength and 15 m obstacle run with significant difference (p < 0.05), girls outperformed boys in Sit forward bend with significant difference (p < 0.05).The 12-week flag rugby game programs improved gross motor skills and physical fitness levels of 5-6 year old preschoolers more comprehensively than the regular program, and we recommend the purposeful and organized promotion of a flag rugby game programs in the physical activity curriculum for 5-6 year old preschoolers.

Angiotensin II type-2 receptor signaling facilitates liver injury repair and regeneration via inactivation of Hippo pathway.

The angiotensin II type 2 receptor (AT2R) is a well-established component of the renin-angiotensin system and is known to counteract classical activation of this system and protect against organ damage. Pharmacological activation of the AT2R has significant therapeutic benefits, including vasodilation, natriuresis, anti-inflammatory activity, and improved insulin sensitivity. However, the precise biological functions of the AT2R in maintaining homeostasis in liver tissue remain largely unexplored. In this study, we found that the AT2R facilitates liver repair and regeneration following acute injury by deactivating Hippo signaling and that interleukin-6 transcriptionally upregulates expression of the AT2R in hepatocytes through STAT3 acting as a transcription activator binding to promoter regions of the AT2R. Subsequently, elevated AT2R levels activate downstream signaling via heterotrimeric G protein Gα12/13-coupled signals to induce Yap activity, thereby contributing to repair and regeneration processes in the liver. Conversely, a deficiency in the AT2R attenuates regeneration of the liver while increasing susceptibility to acetaminophen-induced liver injury. Administration of an AT2R agonist significantly enhances the repair and regeneration capacity of injured liver tissue. Our findings suggest that the AT2R acts as an upstream regulator in the Hippo pathway and is a potential target in the treatment of liver damage.

Incentive policy for the comprehensive development of young medical talents: an evolutionary game study.

Introduction: Currently in China, there is a lack of well-defined and viable incentive mechanisms at the governmental and hospital levels to support the development of young medical talents, thereby hindering their growth Existing studies primarily investigate the current state and trajectory of incentives, yet they inadequately address the distinctive characteristics of various stakeholders involved in medical talent incentive processes, particularly the lack of research on incentive mechanisms with Chinese attributes. Methods: This study adopts evolutionary game theory to investigate the dynamics of replication and the strategies for achieving evolutionary stability in the comprehensive development of young medical talents, considering both scenarios with and without supportive policies. Results: In the absence of any supportive policy measures, the evolutionarily stable strategy (ESS) point is O(0,0), the unstable equilibrium point is C(1,1), and the saddle points are A(0,1), B(1,0). The initial state of the system is at the unstable equilibrium point C(1,1), which means that the young medical talents and medical institutions adopt a combination of strategies (actively seeking comprehensive development and taking incentive measures). Under the scenario with supportive policies, the ESS point is C(1,1), the unstable equilibrium point is O(0,0), and the saddle points are A(0,1), B(1,0). The initial state of the system is at the unstable equilibrium point O(0,0), which means that young medical talents and medical institutions adopt (N,N) strategy combinations (inactively seeking comprehensive development, implementing no incentive measure). Discussion: (1) Government incentives play a crucial role in motivating young medical talents to seek comprehensive development. (2) The level of government incentive support for young medical talents should exceed the cost increment of individual efforts. Additionally, the policy support provided by the government to medical institutions should surpass the incentive support offered by these institutions to young medical talents. This will enhance the motivation and encouragement efforts of medical institutions in actively promoting comprehensive development among young medical talents. (3) With the backing of certain government incentive policies, medical institutions implementing incentive measures and young medical talents actively seeking comprehensive development will establish a virtuous cycle of mutual promotion.

A nomogram based on CT intratumoral and peritumoral radiomics features preoperatively predicts poorly differentiated invasive pulmonary adenocarcinoma manifesting as subsolid or solid lesions: a double-center study.

Background: The novel International Association for the Study of Lung Cancer (IASLC) grading system suggests that poorly differentiated invasive pulmonary adenocarcinoma (IPA) has a worse prognosis. Therefore, prediction of poorly differentiated IPA before treatment can provide an essential reference for therapeutic modality and personalized follow-up strategy. This study intended to train a nomogram based on CT intratumoral and peritumoral radiomics features combined with clinical semantic features, which predicted poorly differentiated IPA and was tested in independent data cohorts regarding models' generalization ability. Methods: We retrospectively recruited 480 patients with IPA appearing as subsolid or solid lesions, confirmed by surgical pathology from two medical centers and collected their CT images and clinical information. Patients from the first center (n =363) were randomly assigned to the development cohort (n = 254) and internal testing cohort (n = 109) in a 7:3 ratio; patients (n = 117) from the second center served as the external testing cohort. Feature selection was performed by univariate analysis, multivariate analysis, Spearman correlation analysis, minimum redundancy maximum relevance, and least absolute shrinkage and selection operator. The area under the receiver operating characteristic curve (AUC) was calculated to evaluate the model performance. Results: The AUCs of the combined model based on intratumoral and peritumoral radiomics signatures in internal testing cohort and external testing cohort were 0.906 and 0.886, respectively. The AUCs of the nomogram that integrated clinical semantic features and combined radiomics signatures in internal testing cohort and external testing cohort were 0.921 and 0.887, respectively. The Delong test showed that the AUCs of the nomogram were significantly higher than that of the clinical semantic model in both the internal testing cohort(0.921 vs 0.789, p< 0.05) and external testing cohort(0.887 vs 0.829, p< 0.05). Conclusion: The nomogram based on CT intratumoral and peritumoral radiomics signatures with clinical semantic features has the potential to predict poorly differentiated IPA manifesting as subsolid or solid lesions preoperatively.

Acenaphthenediimine complex-bridged porphyrin porous organic polymer with enriched active sites as a robust water splitting electrocatalyst.

To realize efficient water splitting, a highly promising hydrogen evolution reaction (HER) electrocatalyst is needed for the generation of hydrogen. Herein, we demonstrate a novel acenaphthenediimine complex-bridged porphyrin porous organic polymer (NiTAPP-NiACQ) with enriched active metal sites and hierarchical pores. The as-prepared NiTAPP-NiACQ exhibits good long-term durability and remarkable HER performance in 1.0 M KOH with a low overpotential of 117 mV at 10 mA cm-2, which is comparable to many previously reported electrocatalytic HER systems. Furthermore, a simple water-alkali electrolyzer using NiTAPP-NiACQ as the cathode requires a small cell voltage of 1.59 V to deliver a current density of 10 mA cm-2 at room temperature, along with outstanding durability. NiTAPP-NiACQ features not only a metal ion as the catalytic active center in the porphyrin core but also metal ion coordination on the anthraquinone component to promote HER performance, enabling multiple metal ions as the electrocatalytic active sites for the HER reaction. The excellent HER activity of NiTAPP-NiACQ is ascribed to a combination of mechanisms. These findings highlight the viability of porphyrin-derived porous organic polymers in energy conversion processes.

Does Prophylactic Closure Improve Outcomes After Colorectal Endoscopic Submucosal Dissection? A Systematic Review and Meta-analysis.

BACKGROUND: Several studies have described prophylactic closure after endoscopic submucosal dissection (ESD) of colorectal lesions for improving postoperative outcomes. We reviewed the evidence on the impact of prophylactic closure after ESD. METHODS: A literature search was conducted on PubMed, Embase, CENTRAL, and Web of Science by 2 reviewers independently for studies published up to July 9, 2023. All types of comparative studies were eligible. RESULTS: Ten studies compared 939 patients undergoing prophylactic closure with 1074 controls. Three were randomized controlled trials (RCTs) while the rest were observational. Pooled data from all included studies showed that prophylactic closure resulted in reduced incidence of delayed bleeding after ESD [odds ratio (OR): 0.30; 95% CI: 0.15, 0.72; I2 =0%]. These results were significant only for observational studies but not for RCTs. Meta-analysis showed no significant difference in the risk of delayed perforation (OR: 0.55; 95% CI: 0.18, 1.70; I2 =0%) or post-ESD coagulation syndrome (PECS) (OR: 1.15; 95% CI: 0.41, 3.19; I2 =63%) between closure and nonclosure groups. CONCLUSIONS: Observational data suggest that prophylactic closure of colorectal mucosal defects after ESD may reduce the risk of delayed bleeding. However, the results are not concurred by RCTs. Furthermore, there seems to be no impact of prophylactic closure on the risk of delayed perforation and PECS.

Angiotensin II type-2 receptor attenuates liver fibrosis progression by suppressing IRE1α-XBP1 pathway.

The renin-angiotensin system (RAS) has been recognized as a crucial contributor to the development of liver fibrosis, and AT2R, an essential component of RAS, is involved in the progression of liver fibrosis. However, the underlying mechanisms by which AT2R modulates liver fibrosis remain elusive. Here, we report that AT2R was induced to be highly expressed during the progression of liver fibrosis, and the elevated AT2R attenuates liver fibrosis by suppressing IRE1α-XBP1 pathway. In this study, we found that AT2R is not expressed in the no cirrhotic adult liver, but is induced expression during liver fibrosis in both cirrhotic patients and fibrotic mice models. Upregulated AT2R inhibits the activation and proliferation of hepatic stellate cells (HSCs). In addition, our study showed that during liver fibrosis, AT2R deletion increased the dimerization activation of IRE1α and promoted XBP1 splicing, and the spliced XBP1s could promote their transcription by binding to the AT2R promoter and repress the IRE1α-XBP1 axis, forming an AT2R-IRE1α-XBP1 negative feedback loop. Importantly, the combination treatment of an AT2R agonist and an endoplasmic reticulum stress (ER stress) alleviator significantly attenuated liver fibrosis in a mouse model of liver fibrosis. Therefore, we conclude that the AT2R-IRE1α signaling pathway can regulate the progression of liver fibrosis, and AT2R is a new potential therapeutic target for treating liver fibrosis.

A trusted medical data sharing framework for edge computing leveraging blockchain and outsourced computation.

Traditional cloud-centric approaches to medical data sharing pose risks related to real-time performance, security, and stability. Medical and healthcare data encounter challenges like data silos, privacy breaches, and transmission latency. In response to these challenges, this paper introduces a blockchain-based framework for trustworthy medical data sharing in edge computing environments. Leveraging healthcare consortium edge blockchains, this framework enables fine-grained access control to medical data. Specifically, it addresses the real-time, multi-attribute authorization challenge in CP-ABE through a Distributed Attribute Authorization strategy (DAA) based on blockchain. Furthermore, it tackles the key security issues in CP-ABE through a Distributed Key Generation protocol (DKG) based on blockchain. To address computational resource constraints in CP-ABE, we enhance a Distributed Modular Exponentiation Outsourcing algorithm (DME) and elevate its verifiable probability to "1". Theoretical analysis establishes the IND-CPA security of this framework in the Random Oracle Model. Experimental results demonstrate the effectiveness of our solution for resource-constrained end-user devices in edge computing environments.

Controllable Photoreduction of Graphene Oxide/Gold Composite Using a Shaped Femtosecond Laser for Multifunctional Sensors.

The mixture of graphene oxide and noble metal nanoparticles has been widely used in flexible multifunctional sensors. Femtosecond lasers are regarded as useful tools for sensor fabrication through direct inscribing. Normally, the laser power is adjusted to optimize the sensing performances. However, the process between the laser and the sample can be effectively altered by the temporal distribution of the pulse and the laser wavelength. This paper proposes a controllable photoreduction of graphene oxide/gold composite method using a shaped femtosecond laser and promotes its application on multifunctional sensors. Different from the strong reliance of the photoreduction process on laser fluence, femtosecond laser shaping expands the controllability range of the photoreduction degree. By combining the parameters of fluence, temporal distribution, laser wavelength, humidity, and strain multifunctional sensors can be both optimized by controlling the laser reduction. The strain sensor exhibits good linearity with a gauge factor of 67.2 in a strain range of 28.2%; the sensitivity of the humidity sensor is improved by 68.4%. The humidity sensor maintains its performance after 28 days, and the strain sensor maintains its stability after 5000 cycles of stretching. The multifunctional sensor can be applied to detect human breath and human pulse and holds value for human health monitoring.

Copper monatomic wire supported on graphene nanoribbons as an electrocatalyst for nitric oxide reduction: pre-adsorption mechanism of reactant.

CONTEXT: This work theoretically demonstrates a catalyst of copper monatomic wire supported on graphene nanoribbons (Cu-GNR) with a high efficiency for nitric oxide electroreduction reaction (NORR). This not only decreases the usage rate of noble metals but also possesses superior limiting potential comparable to pure Cu (- 0.69 and - 0.61 V, vs. reversible hydrogen electrode (RHE)). The key is that Cu-GNR will have more efficient catalytic activity for NORR when fully covered by NO, since these weaken the adsorption ability of the reduction steps at the beginning. In sum, our findings may offer a platform for clarifying the effects of the concentration of reactants on catalytic process. METHODS: Spin-polarized DFT with ultrasoft pseudopotentials as implemented in the CASTEP code was used in this work. The exchange correlation effects were described by generalized gradient approximation (GGA) with Perdew-Burke-Ernzerhof (PBE) functional. The dispersion correction within Grimme scheme (DFT-D2) was employed to accurately describe the van der Waals (vdW) interactions. The Hirshfeld population analysis was adopted to evaluate the charge transfer.

Renal hemodynamic evaluation protocol based on the pathophysiological mechanism of acute kidney injury: Critical Care UltraSound Guided-A(KI)BCDE.

The multiple etiological characteristics of acute kidney injury (AKI) have brought great challenges to its clinical diagnosis and treatment. Renal injury in critically ill patients always indicates hemodynamic injury. The Critical Care UltraSound Guided (CCUSG)-A(KI)BCDE protocol developed by the Chinese Critical Ultrasound Study Group (CCUSG), respectively, includes A(KI) diagnosis and risk assessment and uses B-mode ultrasound, Color doppler ultrasound, spectral Doppler ultrasound, and contrast Enhanced ultrasound to obtain the hemodynamic characteristics of the kidney so that the pathophysiological mechanism of the occurrence and progression of AKI can be captured and the prognosis of AKI can be predicted combined with other clinical information; therefore, the corresponding intervention and treatment strategies can be formulated to achieve targeted, protocolized, and individualized therapy.

Theoretical insight into the essential role of charged surface for ammonia synthesis: Si-decorated carbon nitride electrode.

We report a new Si-decorated carbon nitride (C5N2H2) electrode for the sustainable generation of a hydrogen storage medium, ammonia (NH3), which not only possesses sound electrical conductivity, dynamic stability, and electrochemical activity for the nitric oxide/nitrogen reduction reaction (NORR/NRR), but also provides an option for designing metal-free electrodes. Most importantly, it is found that the charged surface is of great significance to the improved catalytic performance compared to the neutral condition, but this has always been overlooked. Herein, by means of DFT computations, the stubborn chemical bonds of NO and N2 can be entirely activated under an electron density of -2.15 × 10-2 e Å-2 on the Si-C5N2H2 material with an inconsiderable kinetic energy barrier (0.28 eV) along the protonation path. In brief, this finding paves a way for understanding false results by theoretical calculations compared to experiments.

Reactive molecular dynamics simulations on the decomposition process of 1,3,5-trinitro-1,3,5-triazine crystal under high temperatures and pressure.

CONTEXT: Reactive molecular dynamics simulations were performed to study the decomposition processes of 1,3,5-trinitro-1,3,5-triazine (RDX) crystal under high temperatures (2100, 2400, 2700, and 3000 K) and detonation pressure (34.5 GPa) and 0 GPa. It is found that the initial decomposition paths of RDX under different temperatures coupled with detonation pressure are similar, which is due to the N-NO2 bond breakage to release NO2. The formation rates of N2 and H2O are significantly affected by temperature, while those of CO2 are less influenced. The C atoms finally formed C clusters. As the temperature rises, the decomposition speeds up, indicating that the high temperature accelerates the decomposition. Applying pressure can reduce the reaction energy barrier and accelerate the decomposition. METHODS: The RDX model was constructed using the Materials Studio 7.0 package. All MD simulations were performed based on the ReaxFF force field in the LAMMPS software package, and the crystals were visualized using the OVITO software package. The time step was 0.1 fs, and the total MD simulation time was 200 ps. DFT calculations were carried out at the B3LYP/6-311G(d,p) level using the Gaussian 09 package.