The functional properties of glasses are governed by their formation history and the complex relaxation processes they undergo.However,under extreme conditions,glass behaviors are still elusive.In this study,we employ...The functional properties of glasses are governed by their formation history and the complex relaxation processes they undergo.However,under extreme conditions,glass behaviors are still elusive.In this study,we employ simulations with varied protocols to evaluate the effectiveness of different descriptors in predicting mechanical properties across both low-and high-pressure regimes.Our findings demonstrate that conventional structural and configurational descriptors fail to correlate with the mechanical response following pressure release,whereas the activation energy descriptor exhibits robust linearity with shear modulus after correcting for pressure effects.Notably,the soft mode parameter emerges as an ideal and computationally efficient alternative for capturing this mechanical behavior.These findings provide critical insights into the influence of pressure on glassy properties,integrating the distinct features of compressed glasses into a unified theoretical framework.展开更多
On approaching the glass transition,the structural relaxation of glass-forming liquids slows down drastically,along with a significant growth of dynamic heterogeneity.Recent studies have achieved substantial advanceme...On approaching the glass transition,the structural relaxation of glass-forming liquids slows down drastically,along with a significant growth of dynamic heterogeneity.Recent studies have achieved substantial advancements in elucidating the quantitative correlations between structural relaxation and dynamic heterogeneity.Here,we present the discovery of a novel dynamic crossover with possibly universal dynamic signatures by investigating the relationship between structural relaxation and dynamic heterogeneity.Specifically,the structural relaxation time at the dynamic crossoverτ_(c)is equal to the time scale for the maximum non-Gaussian parameter,which could serve as a quantitative characterization of dynamic heterogeneity.The degree of dynamic heterogeneity at the crossover is approximately equivalent across all investigated glass-forming liquids,leading to a scaling collapse between structural relaxation and dynamic heterogeneity.Moreover,the mean squared displacement at the structural relaxation time is nearly constant across different temperatures as long as the structural relaxation time does not exceedτ_(c).We further observe that the temperature at the dynamic crossover is lower than the onset temperature of slow dynamics.Our findings thus suggest the existence of a novel dynamic crossover with possibly universal dynamic signatures in glass-forming liquids,which merits in-depth investigations.展开更多
In this study,we propose an effective strategy for selecting alloying elements to suppress hydrogen diffusion inγ-uranium(γ-U)based on the first-principles investigation of the Niobium(Nb)influences on hydrogen diff...In this study,we propose an effective strategy for selecting alloying elements to suppress hydrogen diffusion inγ-uranium(γ-U)based on the first-principles investigation of the Niobium(Nb)influences on hydrogen diffusion behavior.The simulation results show that the substitution of Nb in the body-centered cubic(bcc)lattice ofγ-U significantly reduces the hydrogen diffusion rate,driven by two key factors:the thermodynamic stabilization of theγ-U bcc lattice and Nb’s strong hydrogen trapping effect.Diffusion energy pathway and electronic structure analyses reveal the presence of energy wells around Nb atoms,causing hydrogen to form cage-like diffusion pathways centered on Nb atoms,which effectively restricts long-range hydrogen diffusion inγ-U.Although Nb’s hydrogen trapping ability decreases at higher hydrogen concentrations,it still plays a crucial role in preventing the nucleation of UH3.Based on these findings,we propose a strategy for predicting hydrogen diffusion kinetics in a series of U-X(X=Ti,Tc,Nb,Mo,Re,Zr,In,Tl)alloys using first-principles static calculations,and establish a near-linear correlation between diffusion energy barriers,X-H bond lengths,and alloy formation energies.Our study underscores the importance of first-principles calculations in selecting suitable alloying elements to regulate hydrogen diffusion in uranium alloys,offering valuable insights with significant implications for engineering applications.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos.T2325004 and 52161160330)the National Natural Science Foundation of China (Grants No.12504233)+2 种基金Advanced MaterialsNational Science and Technology Major Project (Grant No.2024ZD0606900)the Talent Hub for “AI+New Materials” Basic Researchthe Key Research and Development Program of Ningbo (Grant No.2025Z088)。
文摘The functional properties of glasses are governed by their formation history and the complex relaxation processes they undergo.However,under extreme conditions,glass behaviors are still elusive.In this study,we employ simulations with varied protocols to evaluate the effectiveness of different descriptors in predicting mechanical properties across both low-and high-pressure regimes.Our findings demonstrate that conventional structural and configurational descriptors fail to correlate with the mechanical response following pressure release,whereas the activation energy descriptor exhibits robust linearity with shear modulus after correcting for pressure effects.Notably,the soft mode parameter emerges as an ideal and computationally efficient alternative for capturing this mechanical behavior.These findings provide critical insights into the influence of pressure on glassy properties,integrating the distinct features of compressed glasses into a unified theoretical framework.
基金support from the National Natural Science Foundation of China(Grant Nos.12374202 and 12004001)Anhui Projects(Grant Nos.2022AH020009,S020218016,and Z010118169),and Hefei City(Grant No.Z020132009)+3 种基金support from the National Natural Science Foundation of China(Grant Nos.T2325004 and 52161160330)Advanced Materials-National Science and Technology Major Project(Grant No.2024ZD0606900)the Talent Hub for“AI+New Materials”Basic ResearchHefei Advanced Computing Center,Beijing Super Cloud Computing Center,and the High-Performance Computing Platform of Anhui University for providing computing resources.
文摘On approaching the glass transition,the structural relaxation of glass-forming liquids slows down drastically,along with a significant growth of dynamic heterogeneity.Recent studies have achieved substantial advancements in elucidating the quantitative correlations between structural relaxation and dynamic heterogeneity.Here,we present the discovery of a novel dynamic crossover with possibly universal dynamic signatures by investigating the relationship between structural relaxation and dynamic heterogeneity.Specifically,the structural relaxation time at the dynamic crossoverτ_(c)is equal to the time scale for the maximum non-Gaussian parameter,which could serve as a quantitative characterization of dynamic heterogeneity.The degree of dynamic heterogeneity at the crossover is approximately equivalent across all investigated glass-forming liquids,leading to a scaling collapse between structural relaxation and dynamic heterogeneity.Moreover,the mean squared displacement at the structural relaxation time is nearly constant across different temperatures as long as the structural relaxation time does not exceedτ_(c).We further observe that the temperature at the dynamic crossover is lower than the onset temperature of slow dynamics.Our findings thus suggest the existence of a novel dynamic crossover with possibly universal dynamic signatures in glass-forming liquids,which merits in-depth investigations.
基金supported by the National Natural Science Foundation of China (Grant Nos. T2325004, and 52161160330)the computational support from the Beijing Computational Science Research Center (CSRC)
文摘In this study,we propose an effective strategy for selecting alloying elements to suppress hydrogen diffusion inγ-uranium(γ-U)based on the first-principles investigation of the Niobium(Nb)influences on hydrogen diffusion behavior.The simulation results show that the substitution of Nb in the body-centered cubic(bcc)lattice ofγ-U significantly reduces the hydrogen diffusion rate,driven by two key factors:the thermodynamic stabilization of theγ-U bcc lattice and Nb’s strong hydrogen trapping effect.Diffusion energy pathway and electronic structure analyses reveal the presence of energy wells around Nb atoms,causing hydrogen to form cage-like diffusion pathways centered on Nb atoms,which effectively restricts long-range hydrogen diffusion inγ-U.Although Nb’s hydrogen trapping ability decreases at higher hydrogen concentrations,it still plays a crucial role in preventing the nucleation of UH3.Based on these findings,we propose a strategy for predicting hydrogen diffusion kinetics in a series of U-X(X=Ti,Tc,Nb,Mo,Re,Zr,In,Tl)alloys using first-principles static calculations,and establish a near-linear correlation between diffusion energy barriers,X-H bond lengths,and alloy formation energies.Our study underscores the importance of first-principles calculations in selecting suitable alloying elements to regulate hydrogen diffusion in uranium alloys,offering valuable insights with significant implications for engineering applications.
