Accurate pressure measurement in static high-pressure experiments relies on the equation of state (EOS) of standard materials, where uncertainties in EOS parameters can significantly affect the accuracy of pressure predictions. This study focuses on magnesium oxide (MgO, B1 phase) and rhenium (Re, hexagonal close packed phase), employing Bayesian statistical methods and Markov Chain Monte Carlo (MCMC) simulation techniques to systematically quantify the uncertainty in pressure prediction during diamond anvil cell (DAC) experiments. By constructing a Bayesian framework with uniform prior distributions and normal likelihood functions, and integrating multiple sets of experimental data for parameter calibration, the results demonstrate that the Bayesian statistical approach successfully quantifies the posterior distribution of EOS parameters, revealing strong correlations between them, e.g., a negative correlation between Grüneisen parameter and initial volume for MgO, and a positive correlation between bulk modulus and Grüneisen parameter for Re. The uncertainty in pressure predictions for both MgO and Re increases significantly at higher pressures; for Re, this uncertainty also rises markedly with increasing temperature, whereas no clear trend is observed for MgO. This study provides pressure benchmarks with quantified uncertainties, contributing to improved accuracy in high-pressure experimental measurements. It holds significant reference value for ensuring the reliability of experimental data in materials science and geophysical research.

Metallic tin is a focal point in high-pressure physics research and a critical material of strategic importance in defense-related technologies. Due to the rich physical phases of tin, it is crucial to study the multiphase equation of state and phase boundaries of tin, whether in basic research or industrial applications. This work systematically investigates the high-temperature and high-pressure multiphase equation of state (EOS), phase boundaries, elastic modulus, sound velocities, and Hugoniot curves of tin using density functional theory (DFT) combined with the mean-field potential (MFP) method. The results not only provide the multiphase EOS of tin under extreme conditions but also demonstrate good agreement with experimental data for the β-γ phase boundary and ambient-pressure sound velocities of β-Sn. Furthermore, this study evaluates the effects of different density functionals (LDA, PBEsol, and SCAN) on the high-pressure EOS. The LDA and PBEsol functionals show superior consistency with experimental Hugoniot curves and ambient-pressure elastic moduli, while the SCAN functional exhibits larger deviations in phase boundary predictions but achieves closer agreement with experimental ambient-pressure sound velocities for β-Sn.

Micro-jetting and micro-spallation at metal interfaces under intense shock loading play pivotal roles in applications such as inertial confinement fusion (ICF). These phenomena exhibit inherent complexity due to their multi-scale dynamics, strong nonlinearity, and coupled multi-field interactions. Under extreme irradiation conditions, the formation of high-pressure nanoscale helium bubbles significantly alters interface failure mechanisms. Using molecular dynamics methods, we investigate micro-jet growth and damage evolution in helium-containing copper subjected to double supported shock loadings. Helium bubbles demonstrate lower critical activation stress thresholds for expansion compared to void nucleation, with these thresholds being dependent on bubble distribution and number density. Under low-pressure primary shocks, helium-containing metals produce more pronounced micro-jets than pure metals. During secondary shocks, helium bubbles promote jet fragmentation, resulting in higher maximum velocities at micro-jet tips while maintaining comparable velocity distributions in micro-jet bodies. Secondary shocks show negligible effects on bulk helium bubbles that were previously compressed by initial shocks and partially rebounded due to rarefaction waves without complete recovery. Near-surface ruptured bubble walls may reattach to bubble bases after secondary shocks, temporarily re-trapping helium atoms that are subsequently released during unloading-induced re-expansion and rupture. The collapse mechanism of helium bubbles under secondary shock is closely related to the helium bubbles size and the strength of secondary shock. This study establishes fundamental physical understanding and provides a theoretical foundation for future cross-scale investigations of coupled micro-jetting and micro-spallation evolution in irradiated helium-containing metals.

By combining first-principles calculations under the framework of density functional theory (DFT) and the CALYPSO crystal structure prediction method, the structural stability of the inert element helium (He) and alkaline-earth metals under high-pressure conditions has been systematically investigated. The calculations reveal that among the alkaline-earth metals, strontium (Sr) forms compounds with He exhibiting relatively low energy values. Consequently, the crystal structure of Sr₂He at 400 GPa was predicted. Electron localization function (ELF) and density of states (DOS) analyses show no tendency for covalent bond formation between Sr and He atoms. Furthermore, Bader charge analysis reveals ionic bonding between Sr and He atoms, with charge transfer occurring from He to Sr. These results provide key insights into the bonding mechanism of Sr₂He. This study elucidates the crystal structure, bonding nature, and electronic properties of Sr₂He, offering theoretical support for understanding the stability and physical properties of such metastable materials and providing important guidance for their experimental synthesis.