The propagation behavior of reaction wave for Ni/Al clad particle composites under shock loading.

Prior studies indicate that the reaction wave can propagate from the impact surface, but the possibility and the influencing factors of the reaction wave formation are still unclear. This work investigates the propagation behavior of the shock-induced reaction wave for Ni/Al clad particle composites with varying stoichiometry (from 0.5 to 0.75 of the Ni mole fraction) through molecular dynamics simulations. It is found that the solid-state reaction processes with or without wave propagation strongly depend on the conjunction of stoichiometry and shock intensity. Within the cases of wave propagation, the calculated propagation velocity (in the range of 135-170 m/s) increases linearly or exponentially with the Ni mole fraction. Furthermore, the thermodynamic criteria for the reaction wave formation, including Al melting at the collision surface and higher temperature gradient, are established by analysis of the shock-induced high-entropy layer. In addition, microstructural characterization reveals the intrinsic mechanisms of the propagation of the reaction wave and the formation of additional reaction wave, namely, the dissolution of Ni into Al and the coalescence of reaction zones. Apart from the propagation behavior, the initial stoichiometry influences the crystallization-dissolution of B2-NiAl during reaction processes, notably through an exponential growth relationship between maximum crystallinity and the Ni mole fraction. These findings may provide a physical basis for improving traditional reaction rate models to break through phenomenological understanding.

Deformation, damage, and reaction characteristics during the collision between Ni and Al nanoparticles.

The exothermic reaction during the collision between nanoparticles is of importance for the engineering applications of energetic powder materials. This work investigates collision-induced nanoparticle deformation, damage and reaction characteristics in a reactive Ni/Al system via molecular dynamics simulations. The morphological changes and reaction process are explored thoroughly for a wide range of impact velocities v and initial particle radius R. For lower impact velocities (1 km s-1 ≤ v ≤ 1.5 km s-1), the fully melted Al gradually clad the plastic deformed Ni nanoparticles to form an Al-shell/Ni-core structure, and the morphology ultimately develop into a nearly spherical shape possessing minimal surface energy. During this period, the self-sustaining reaction driven by the diffusion of Ni atoms into molten Al leads to slow melting of Ni nanoparticles, and the reaction and melting rates increase with the decrease of the particle radius. There exists one critical radius (R = 10 nm) beyond which the reaction is severely blocked due to the occurrence of fracture behavior at v = 1.5 km s-1. For intermediate velocities (2 km s-1 ≤ v < 3 km s-1), collision-induced debris clouds are observed, which satisfies the power-law distribution in the size of debris and results in an obvious reduction of the final reaction degree. Interestingly, we found that the reactive component in generated debris is lower for the larger-radius nanoparticle, which is also responsible for the lower final reaction degree and thermal kinetic energy. For higher velocities (v ≥ 3 km s-1), the occurrence of spallation damage reduces the contact area due to the formed micro-voids within Al and Ni nanoparticles and consequently the final reaction degree further.

Atomic insights into shock-induced alloying reaction of premixed Ni/Al nanolaminates.

In material processing and handling processes, premixed interlayer often replace the ideal Ni/Al interface, which would become a new origin of alloying reaction. This work investigates shock-induced reaction mechanism and kinetics of premixed Ni/Al nanolaminates with molecular dynamics simulations and theoretical analysis. The reaction is found to be driven by the crystallization evolution in premixed interlayer and the diffusion of premixed atoms. Among them, multi-stage reaction patterns are strongly manifested by the crystallization evolution characteristics. Specifically, "crystallization-dissolution-secondary growth" and "crystallization-dissolution" of B2 phase respectively correspond to the solid-state and solid-liquid reaction cases, where crystallizations are fitted well by Johnson-Mehl-Avrami kinetics model. Interestingly, the different growth mechanisms of B2 grain are revealed, namely nuclei coalescence and atomic diffusion. Moreover, the analysis of microscopic diffusion theory indicates a certain non-random diffusion nature for solid-state reaction initiation, but near-purely random diffusion for solid-liquid reaction initiation. The diffused Al atoms possess a limited diffusion coefficient and enhanced diffusion correlation, resulting in extremely slow mixing rate in Ni layer. In addition, the influence law of Ni concentration in premixed interlayer on reactivity parameters can be quantitatively described by a quadratic function.

Atomistic study on reaction kinetics and reactivity of Ni/Al clad particles composites under shock loading.

In prior research on shock-induced reaction, the interfacial crystallization of intermetallics, which plays an important role in solid-state reaction kinetics, has not been explored in detail. This work comprehensively investigates the reaction kinetics and reactivity of Ni/Al clad particle composites under shock loading with molecular dynamics simulations. It is found that the reaction acceleration in a small particle system or the reaction propagation in a large particle system breaks down the heterogeneous nucleation and continuous growth of B2 phase at the Ni/Al interface. This makes the generation and dissolution of B2-NiAl show a staged pattern consistent with chemical evolution. Importantly, the crystallization processes are appropriately described by the well-established Johnson-Mehl-Avrami kinetics model. With the increase in Al particle size, the maximum crystallinity and growth rate of B2 phase decrease and the value of the fitted Avrami exponent decreases from 0.55 to 0.39, showing a good agreement with the solid-state reaction experiment. In addition, the calculations of reactivity reveal that the reaction initiation and propagation will be retarded, but the adiabatic reaction temperature can be elevated when Al particle size increases. An exponential decay relationship is found between the propagation velocity of the chemical front and the particle size. As expected, the shock simulations at non-ambient conditions indicate that elevating the initial temperature significantly enhances the reactivity of large particle systems and results in a power-law decrease in the ignition delay time and a linear-law increase in the propagation velocity.

Determining the origin of poor electronic conductivity and ultrafast ionic conductivity in Na3V2(PO4)2FO2 based on first principles and ab initio molecular dynamics methods.

Sodium ion technology is increasingly investigated as a low-cost solution for grid storage applications. Among the reported cathode materials for sodium-ion batteries, Na3V2(PO4)2FO2 is considered as one of the most promising materials due to its high operation voltage and good cyclability. Here, the de-sodiumization process of Na3V2(PO4)2FO2 has been systematically examined using first-principles calculations to uncover the fundamental questions at the atomic level. Four stable intermediate products during the de-sodiumization process are firstly determined based on the convex hull, and three voltage platforms are then predicted. Except for two voltage platforms (3.37 V and 3.75 V) close to the experimental values, the platform up to 5.28 V exceeds the stability window (4.8 V) of a typical electrolyte, which was not observed experimentally. Excitingly, the change of volume is only 2% during the sodiumization process, which should be the reason for the good cycling stability of this material. Electronic structure analysis also reveals that the valence states of V ions will be changed from V5+ to V4+ during the sodiumization process, resulting in a weak Jahn-Teller distortion in VO5F octahedra, and then making the lattice-constants asymmetrically change. More seriously, combined with a bandgap of 2.0 eV, the conduction band minimum mainly composed of V-t2g non-bonding orbitals has strong localized characteristics, which should be the intrinsic origin of poor electron transport properties for NaxV2(PO4)2FO2. Nonetheless, benefiting from the layer-like structure features with F-segmentation, this material has an ultrafast sodium ionic conductivity comparable to that of NASICON, with an activation energy of only 82 meV. Therefore, our results indicate that maintaining layer-like features and regulating V atoms will be important directions to improve the performance of NaxV2(PO4)2FO2.

Photoacoustically assisted material ejection from fused SiO2 following UV nanosecond laser ablation.

When an ultraviolet nanosecond laser focuses on the rear surface of a fused SiO2 sample through its front surface, two internal shock waves (SWs) generating from the rear surface propagate toward the front surface. These SWs are derived as the consequence of different physical processes giving rise to ablation particles. They will induce micro-ejection particles from the existing micro-crater sculpted by the laser at the front surface, if their intensities are higher than the yield strength of the material. Atomistic simulations reveal the formation mechanism of shock-induced ejection from the ablated defects. Photoacoustically assisted material ejection has been theoretically and experimentally verified.

A boron-exposed TiB3 monolayer with a lower electrostatic-potential surface as a higher-performance anode material for Li-ion and Na-ion batteries.

The lack of high-performance anode materials has become a major obstacle to the development of Li- and Na-ion batteries. Recently, 2D transition metal borides (e.g. MBenes) have attracted much attention due to their excellent stability and electrical conductivity. Unfortunately, most of the reported MBene phases typically have an intrinsic metal-rich structure with metal atoms exposed on the surface, which harmfully affect the adsorption of Li/Na atoms. Here, through crystal structure prediction combined with the first-principles density functional theory, a novel TiB3 MBene has been determined by altering the proportion of non-metallic element boron to wrap metal atoms and weaken nearest-neighbor electrostatic repulsion. Electrostatic potential analysis visually shows a surface with low potential on the TiB3 monolayer implying high adsorption capacity, and also can be used to quickly screen out the Li/Na adsorption sites. Accurate half-cell battery simulation confirmably shows that the TiB3 monolayer possesses a theoretical specific capacity of 1335.04 and 667.52 mA h g-1 for Li and Na, respectively. The TiB3 monolayer can remain metallic after adsorbing Li/Na atoms, which ensures good conductivity during battery cycling. The ultra-low barrier energy (only 38 meV for Li) and suitable open-circuit voltage indicate excellent charging and discharging capabilities. These results suggest that the TiB3 monolayer could be a promising anode material for Li- and Na-ion batteries, and provide a simple design principle for exposing non-metallic atoms on the surface.

Suppression of LINC00707 alleviates lipopolysaccharide-induced inflammation and apoptosis in PC-12 cells by regulated miR-30a-5p/Neurod 1.

Long noncoding RNA (lncRNA) has emerged as a pivotal regulator improving neural regeneration in the progression of spinal cord injury (SCI). However, whether lncRNAs can be targeted for therapeutic intervention of SCI remains unclear. In this study, we found that LINC00707 expression was significantly up-regulated in lipopolysaccharide (LPS)-treated PC-12, a model that mimics nerve cell injury in an inflammatory environment after SCI. Suppression of LINC00707 alleviated LPS-induced inflammation and apoptosis in PC-12 cells. Furthermore, we found that LINC00707 adsorbed miR-30a-5p and silenced miR-30a-5p or overexpressed Neurod 1 reversed the effect of LINC00707 on the inflammation and apoptosis of LPS-treated PC-12 cells. These findings revealed that LINC00707 alleviates LPS-induced inflammation and apoptosis in PC-12 cells by targeting miR-30a-5p/Neurod 1, providing a preliminary theoretical basis for the clinical application of LINC00707 in SCI.

microRNA-338-3p inhibits proliferation, migration, invasion, and EMT in osteosarcoma cells by targeting activator of 90 kDa heat shock protein ATPase homolog 1.

BACKGROUND: Osteosarcoma (OS) is a rare, malignant bone tumor that primarily affects adolescents and has a high degree of malignancy and high incidence of recurrence and metastasis. Our study aimed to explore the role of miR-338-3p in OS cells. METHODS: qRT-qPCR was performed to quantify miR-338-3p expression levels in OS tissue samples and in three common OS cell lines. MG-63 and Saos2 cells were separately transfected with miR-338-3p or NC mimics and miR-338-3p expression levels was determined by qRT-PCR. Cell proliferation was monitored using the Cell Counting Kit-8. Flow cytometer analysis was carried out to determine the distribution of cell cycle stages and apoptosis. Transwell assay was performed to measure the migratory and invasive capacities of MG-63 and Saos2 cells. The expression of Vimentin and E-cadherin was detected by western blot. Luciferase reporter assay, qRT-PCR and western blotting were performed to confirm the target of miR-338-3p. RESULTS: Analysis by qRT-PCR revealed that miR-338-3p was downregulated in the tissue samples of 20 OS patients when compared with that in their matched adjacent non-tumor tissues. Furthermore, miR-338-3p was significantly downregulated in three common OS cell lines, namely, MG-63, Saos2, and HOS, when compared with that in the human osteoblast cell line hFOB1.19. Analysis by luciferase reporter assay, qRT-PCR, and western blotting revealed that activator of 90 kDa heat shock protein ATPase homolog 1 (AHSA1) is a direct target of miR-338-3p. miR-338-3p overexpression led to significant reduction in AHSA1 protein levels in MG63 and Saos2 cells. miR-338-3p overexpression reduced cell viability and migration and invasion behavior of MG63 and Saos2 cells. In addition, miR-338-3p overexpression suppressed epithelial-mesenchymal transition (EMT), induced a significant G1-phase arrest and did not affect the apoptosis in both MG-63 and Saos2 cells. Moreover, overexpression of AHSA1 reversed the inhibitory effect of miR-338-3p overexpression on proliferation, cell cycle, apoptosis, EMT, migration, and invasion of MG63 and Saos2 cells, thereby suggesting that miR-338-3p acts as a tumor suppressor in OS cells by targeting AHSA1. CONCLUSIONS: miR-338-3p/AHSA1 can serve as a potential therapeutic target for OS therapy.

microRNA-377 suppresses the proliferation of human osteosarcoma MG-63 cells by targeting CDK6.

MicroRNAs (miRNAs) are essential to the progression of osteosarcoma. Previous research using osteosarcoma samples confirmed that miR-377 expression is less than that observed in normal human osteoblast expression. These data suggest a role for miR-377 in osteosarcoma that warrants investigation. To address this concept, we measured miR-377 expression in two cell models, and we also observed that miR-377 was less expressed in osteosarcoma MG-63 cells compared to the hFOB1.19 human fetal osteoblastic cell line. Moreover, miR-377 overexpression reduced cell proliferation and suppressed invasion of MG-63 cells but had no effect on MG-63 cell apoptosis. Because cyclin-dependent kinase 6 (CDK6) may be a potential target of miR-377 in osteosarcoma cells, we overexpressed CDK6 and observed that overexpression attenuated tumor suppressive effects of miR-377 on cell proliferation. Our data suggest that miR-377 can suppress proliferation in MG-63 cells in part by targeting CDK6.

Investigation of fragment sizes in laser-driven shock-loaded tin with improved watershed segmentation method.

Studying dynamic fragmentation in shock-loaded metals and evaluating the geometrical and kinematical properties of the resulting fragments are of significant importance in shock physics, material science as well as microstructural modeling. In this paper, we performed the laser-driven shock-loaded experiment on the Shenguang-Ш (SGШ) prototype laser facility, and employed X-ray micro-tomography technique to give a whole insight into the actual fragmentation process. To investigate the size distribution of the soft recovered fragments from Poly 4-methyl-1-pentene (PMP) foam sample, we further developed an automatic analysis approach based on the improved watershed segmentation. Comparison results of segmenting fragments in slices with different methods demonstrated that our proposed segmentation method can overcome the drawbacks of under-segmentation and over-segmentation, and has the best performance in both segmentation accuracy and robustness. With the proposed automatic analysis approach, other parameters such as the position distribution and penetration depth are also obtained, which are very helpful for understanding the dynamic failure mechanisms.

Mechanism and early warning of coal mine rockburst accident based on SD-STAMP-DEMATEL.

As coal mines shift from shallow to deeper excavation, the number of mines facing the risk of rock burst disasters is gradually increasing. Rockburst, with their characteristics of vibration, suddenness, complexity, and unpredictability, make it increasingly difficult to prevent and control these disasters. Therefore, the challenges of preventing and controlling rock burst disasters are becoming more and more severe. This paper, based on the system-theoretic accident model and processes (STAMP) theory, extracts the causal factors affecting coal mine rock burst accidents. Using the interpretative structural modeling (ISM) and decision-making trial and evaluation laboratory (DEMATEL) method, the accident-causing factors are quantitatively assigned. By constructing model equations and drawing causal loop diagrams and stock-flow diagrams, the event is dynamically simulated and early warnings are issued. The results show that the control defects leading to the accident are analyzed from the perspectives of the government level, management level, grassroots level, physical layer, and the dynamic process of the accident. In the short term, safety investment in grassroots operations is the most effective control. In the long run, the most effective measure is for the management level to strengthen its supervisory work. By changing the input ratios of various variables, it can be seen that different variables in the system dynamics (SD) model have different impacts on coal mine rock burst accidents. It is necessary to continuously strengthen the implementation of the safety responsibility system, improve the work efficiency of the government and management level, and enhance the timeliness of emergency decision-making.

Time series prediction model using LSTM-Transformer neural network for mine water inflow.

Mine flooding accidents have occurred frequently in recent years, and the predicting of mine water inflow is one of the most crucial flood warning indicators. Further, the mine water inflow is characterized by non-linearity and instability, making it difficult to predict. Accordingly, we propose a time series prediction model based on the fusion of the Transformer algorithm, which relies on self-attention, and the LSTM algorithm, which captures long-term dependencies. In this paper, Baotailong mine water inflow in Heilongjiang Province is used as sample data, and the sample data is divided into different ratios of the training set and test set in order to obtain optimal prediction results. In this study, we demonstrate that the LSTM-Transformer model exhibits the highest training accuracy when the ratio is 7:3. To improve the efficiency of search, the combination of random search and Bayesian optimization is used to determine the network model parameters and regularization parameters. Finally, in order to verify the accuracy of the LSTM-Transformer model, the LSTM-Transformer model is compared with LSTM, CNN, Transformer and CNN-LSTM models. The results prove that LSTM-Transformer has the highest prediction accuracy, and all the indicators of its model are well improved.

Atomistic Insights into Impact-Induced Energy Release and Deformation of Core-Shell-Structured Ni/Al Nanoparticle in an Oxygen Environment.

In actual atmospheric environments, Ni/Al composites subjected to high-velocity impact will undergo both intermetallic reaction and oxidative combustion simultaneously, and the coupling of mechanical and multiple chemical processes leads to extremely complex characteristics of energy release. This work employs ReaxFF molecular dynamics simulations to investigate the impact-induced deformation and energy release of a core-shell-structured Ni/Al nanoparticle in an oxygen environment. It was found that Al directly undergoes fragmentation, while Ni experiences plastic deformation, melting, and fragmentation in sequence as the impact velocity increased. This results in the final morphology of the nanoparticles being an ellipsoidal-clad nanoparticle, spherical Ni/Al melt, and debris cloud. Furthermore, these deformation characteristics are strongly related to the material property of the shell, manifested as Ni shell-Al core particle, being more prone to breakage. Interestingly, the dissociation phenomenon of Ni-Al-O clusters during deformation is observed, which is driven by Ni dissociation and Al oxidation. In addition, the energy release is strongly related to the deformation behavior. When the nanoparticle is not completely broken (Ni undergoes plastic deformation and melting), the energy release comes from the oxidative combustion of Al fragments and the intermetallic reaction driven by atomic mixing. When the nanoparticle is completely broken, the energy release mainly comes from the oxidative combustion of the debris cloud. At the same time, the promoting effect of oxygen concentration on the energy release efficiency is examined. These findings can provide atomic insights into the regulation of impact-induced energy release for reactive intermetallic materials.

Unraveling Anisotropy in Crystalline Orientation under Shock-Induced Dynamic Responses in High-Entropy Alloy Co25Ni25Fe25Al7.5Cu17.5.

Shock-induced plastic deformation and spall damage in the single-crystalline FCC Co25Ni25Fe25Al7.5Cu17.5 high-entropy alloy (HEA) under varying shock intensities were systematically investigated using large-scale molecular dynamics simulations. The study reveals the significant influence of crystalline orientation on the deformation mechanism and spall damage. Specifically, the shock wave velocities in the [110] and [111] directions are significantly higher than that in the [001] direction, resulting in a two-zone elastic-plastic shock wave structure observed in the [110] and [111] samples, while only a single-wave structure is found in the [001] sample. The plastic deformation is dominated by the FCC to BCC transformation following the Bain path and a small amount of stacking faults during the compression stage in the [001] sample, whereas it depends on the stacking faults induced by Shockley dislocation motion in the [110] and [111] samples. The stacking faults and phase transformation in the [001] sample exhibit high reversibility under release effects, while extensive dislocations are present in the [110] and [111] samples after release. Interestingly, tension-strain-induced FCC to BCC phase transformation is observed in the [001] sample during the release stage, resulting in increased spall strength compared to the [110] and [111] samples. The spall strength estimated from both bulk and free surface velocity history shows reasonable consistency. Additionally, the spall strength remains stable with increasing shock intensities. The study discusses in detail the shock wave propagation, microstructure change, and spall damage evolution. Overall, our comprehensive studies provide deep insights into the deformation and fracture mechanisms of Co25Ni25Fe25Al7.5Cu17.5 HEA under shock loading, contributing to a better understanding of dynamic deformation under extreme environments.

The Shock-Induced Deformation and Spallation Failure of Bicrystal Copper with a Nanoscale Helium Bubble via Molecular Dynamics Simulations.

Both the nanoscale helium (He) bubble and grain boundaries (GBs) play important roles in the dynamic mechanical behavior of irradiated nanocrystalline materials. Using molecular dynamics simulations, we study the shock-induced deformation and spallation failure of bicrystal copper with a nanoscale He bubble. Two extreme loading directions (perpendicular or parallel to the GB plane) and various impact velocities (0.5-2.5 km/s) are considered. Our results reveal that the He bubble shows hindrance to the propagation of shock waves at lower impact velocities but will accelerate shock wave propagation at higher impact velocities due to the local compression wave generated by the collapse of the He bubble. The parallel loading direction is found to have a greater effect on He bubble deformation during shock compression. The He bubble will slightly reduce the spall strength of the material at lower impact velocities but has a limited effect on the spallation process, which is dominated by the evolution of the GB. At lower impact velocities, the mechanism of spall damage is dominated by the cleavage fracture along the GB plane for the perpendicular loading condition but dominated by the He bubble expansion and void growth for the parallel loading condition. At higher impact velocities, micro-spallation occurs for both loading conditions, and the effects of GBs and He bubbles can be ignored.

Strategic sampling with stochastic surface walking for machine learning force fields in iron's bcc-hcp phase transitions.

This study developed a machine learning-based force field for simulating the bcc-hcp phase transitions of iron. By employing traditional molecular dynamics sampling methods and stochastic surface walking sampling methods, combined with Bayesian inference, we construct an efficient machine learning potential for iron. By using SOAP descriptors to map structural data, we find that the machine learning force field exhibits good coverage in the phase transition space. Accuracy evaluation shows that the machine learning force field has small errors compared to DFT calculations in terms of energy, force, and stress evaluations, indicating excellent reproducibility. Additionally, the machine learning force field accurately predicts the stable crystal structure parameters, elastic constants, and bulk modulus of bcc and hcp phases of iron, and demonstrates good performance in predicting higher-order derivatives and phase transition processes, as evidenced by comparisons with DFT calculations and existing experimental data. Therefore, our study provides an effective tool for investigating the phase transitions of iron using machine learning methods, offering new insights and approaches for materials science and solid-state physics research.

Rock Damage Model Coupled Stress-Seepage and Its Application in Water Inrush from Faults in Coal Mines.

Mining-induced fractures often constitute water inrush channels, which lead to mine water inrush accidents. In this paper, a coupled model of stress-seepage-damage based on micromechanics is established, which simulates the initiation and propagation of cracks in rock materials and their interaction with fluid flow. The method combines the continuous damage model with the effective stress principle, in which the elastic modulus and permeability are related to the damage variables. The model is implemented via the COMSOL code based on the finite element method, and the reliability of the model is verified by the axial compression-seepage test of standard rock samples. According to the actual geological conditions of F13 fault in Wugou Coal Mine, Anhui Province, the damage of the floor rock mass and the risk of fault water inrush in the 1033 mining face with 50, 40, 30, and 20 m waterproof coal pillars are predicted. When the coal pillar width is 30 or 20 m, the fault, the surrounding rock of the fault, and the failure zone of the floor constitute the water inrush channel. This model provides an intuitive understanding of the rock damage and water inrush evolution, which is difficult to observe, and will contribute to prevent water inrush disasters in practical engineering.

Simulation of the activation of mining faults and grouting reinforcement under thick loose layer and thin bedrock.

We have investigated the activation characteristics of mining faults and the effect of grouting reinforcement under thick loose layer and thin bedrock of the working face and evaluate their impact on the safety of mining at similar working faces. Implementing the geological conditions of the 331 working face of the Yangcun Coal Mine (China) of the Yankuang Energy Group Corporation, we have analyzed mechanically the process of fault activation at first. Subsequently, we have obtained the mechanical criterion of fault slip and the expression of relative strength of the nearby rock mass. Using numerical software we have simulated and analyzed the damage characteristics of different bedrock thicknesses on overlying rocks and faults in the fluid-solid coupling mode. In addition, we have studied the controlling effect of grouting reinforcement on fault activation, which has been verified in the field. The main results of our study show that: 1. The mechanical properties of the rock mass near the fault interface have changed and they are related to the cohesive force of the interface; 2. The water inrush mode of the working face changes under different bedrock thickness, and the thinner the bedrock, the less easily the fault is destroyed 3. The slip of the high-level fault is reduced after the grouting of the fault, the propagation of the fracture zone at the fault is suppressed, the seepage of the aquifer water is prevented, and the safe recovery is realized. The results of our study provide a scientific basis for the secure mining across the fault of the 331 working face of Yangcun Coal Mine. Based on the results of our study the working face can be mined safely from now on and in the future.