Molecular dynamics simulation of irradiation damage is critical for understanding microstructural evolution and defect formation in zirconium carbide (ZrC). However, the absence of a suitable interatomic potential rem...
Molecular dynamics simulation of irradiation damage is critical for understanding microstructural evolution and defect formation in zirconium carbide (ZrC). However, the absence of a suitable interatomic potential remains a challenge. Here, we develop a precise deep-neural-network based machine learning interatomic potential tailored for investigating irradiation damage in ZrC. Our model accurately reproduces the energetics and kinetics of native point defects, thermodynamics properties, surface energies, and generalized stacking fault energies. We further explore collision cascades spanning a range of primary knock-on atom energies (from 1 keV to 40 keV), types (C and Zr), and directions (〈100〉, 〈010〉, and 〈111〉) at 300 K. The results reveal carbon interstitial atoms and vacancies as the dominant point defects, consistent with first-principles calculations, with the notable formation of carbon-rich clusters within collision cascades. These carbon-rich defect clusters, resembling “black-dot” structures in experimental observations, emerge directly in collision cascades and remain thermodynamically stable at low temperatures due to the low mobility of Zr interstitial atoms. In contrast to the absence of dislocation loops in the collision cascade simulations, our results suggest a thermally-driven mechanism for the formation and transformation of 1/3 〈111〉 and 1/2 〈110〉 dislocation loops. This work enriches our understanding of the irradiation damage mechanism in ZrC and other carbide ceramics.
Impurity agglomeration has a significant influence on shock response of metal *** this paper,the mechanism of Ti-clusters in metal Al under shock loading is investigated by non-equilibrium molecular dynamics *** resul...
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Impurity agglomeration has a significant influence on shock response of metal *** this paper,the mechanism of Ti-clusters in metal Al under shock loading is investigated by non-equilibrium molecular dynamics *** results show that the Ti-cluster has obvious effects on the dislocation initiation and melting of bulk ***,the Ti clusters induces the strain concentrate and leads the dislocations to be initiated from the interface of Ti ***,dislocation distribution from the Ti-cluster model results in a formation of a grid-like structure,while the dislocation density is reduced compared with that from the perfect Al ***,the critical shock velocity of dislocation from the Ti-cluster model is lower than from perfect Al ***,it is also found that the temperature near the interface of Ti-cluster is100 K–150 K higher than in the other areas,which means that Ti-cluster interface melts earlier than the bulk area.
At present, the technology of reactor neutron noise is developing rapidly, which can not only be used to measure some intrinsic parameters of the reactor core, but also be used for core fault diagnosis. The theoretica...
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We consider a non-isentropic Euler-Poisson system with two small parameters arising in the modeling of unmagnetized plasmas and *** the basis of the energy estimates and the compactness theorem,the uniform global exis...
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We consider a non-isentropic Euler-Poisson system with two small parameters arising in the modeling of unmagnetized plasmas and *** the basis of the energy estimates and the compactness theorem,the uniform global existence of the solutions and the combined quasi-neutral and zero-electron-mass limit of the system are proved when the initial data are close to the constant equilibrium *** particular,the limit is rigorously justified as the two parameters tend to zero independently.
Determining the mass of plutonium metal is an important research objective in the field of nuclear material accounting and *** on the 3D neutron and photon transport code JMCT(Jointed Monte Carlo Transport),the gamma ...
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Determining the mass of plutonium metal is an important research objective in the field of nuclear material accounting and *** on the 3D neutron and photon transport code JMCT(Jointed Monte Carlo Transport),the gamma ray multiplicity of ^(240)Pu was simulated in this study,and the average number of gamma rays leaking from ^(240)Pu solid spheres with different masses was also *** simulation results show that there is a oneto-one correspondence between the average number of gamma rays and the mass of ^(240)Pu solid spheres in the range of 0.50–3.00 *** result provides a basis for using the average number of gamma rays to account for the mass of ^(240)Pu.
The paper investigates the well-posedness of global solutions and the existence of global attractors for weakly damped FDS nonlinear wave *** establishes the well-posedness of weak solutions using Galerkin approximati...
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The paper investigates the well-posedness of global solutions and the existence of global attractors for weakly damped FDS nonlinear wave *** establishes the well-posedness of weak solutions using Galerkin approximation and a priori ***,a dynamical system is constructed based on the well-posedness of the *** existence of a bounded absorbing set for the equations and the smooth properties of the operator semigroup are presented,leading to the existence of a global attractor.
Disordered hyperuniform many-body systems are exotic states of matter with novel optical, transport, and mechanical properties. These systems are characterized by an anomalous suppression of large-scale density fluctu...
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Disordered hyperuniform many-body systems are exotic states of matter with novel optical, transport, and mechanical properties. These systems are characterized by an anomalous suppression of large-scale density fluctuations compared to ordinary liquids. The structure factor of disordered hyperuniform systems often obeys the scaling relation S(k)∼Bkα with B,α>0 in the limit k→0. Ground states of d-dimensional free fermionic gases, which are fundamental models for many metals and semiconductors, are key examples of quantum disordered hyperuniform states with important connections to random matrix theory. However, the effects of electron-electron interactions as well as the polarization of the electron liquid on hyperuniformity have not been explored thus far. In this paper, we systematically address these questions by deriving the analytical small-k behaviors (and, associated, α and B) of the total and spin-resolved structure factors of quasi-one-dimensional, two-dimensional, and three-dimensional electron liquids for varying polarizations and interaction parameters. We validate that these equilibrium disordered ground states are hyperuniform, as dictated by the fluctuation-compressibility relation. Interestingly, free fermions, partially polarized interacting fermions, and fully polarized interacting fermions are characterized by different values of the small-k scaling exponent α and coefficient B. In particular, partially polarized fermionic liquids exhibit a unique form of multihyperuniformity, in which the net configuration exhibits a stronger form of hyperuniformity (i.e., larger α) than each individual spin component. The detailed theoretical analysis of such small-k behaviors enables the construction of corresponding equilibrium classical systems under effective one- and two-body interactions that mimic the pair statistics of quantum electron liquids. Our paper thus reveals that highly unusual hyperuniform and multihyperuniform states can be achieved in simple
A partial Runge-Kutta Discontinuous Galerkin(RKDG)method which preserves the exactly divergence-free property of the magnetic field is proposed in this paper to solve the two-dimensional ideal compressible magnetohydr...
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A partial Runge-Kutta Discontinuous Galerkin(RKDG)method which preserves the exactly divergence-free property of the magnetic field is proposed in this paper to solve the two-dimensional ideal compressible magnetohydrodynamics(MHD)equations written in semi-Lagrangian formulation on moving quadrilateral *** this method,the fluid part of the ideal MHD equations along with zcomponent of the magnetic induction equation is discretized by the RKDG method as our previous paper[47].The numerical magnetic field in the remaining two directions(i.e.,x and y)are constructed by using the magnetic flux-freezing principle which is the integral form of the magnetic induction equation of the ideal *** the divergence of the magnetic field in 2D is independent of its z-direction component,an exactly divergence-free numerical magnetic field can be obtained by this *** propose a new nodal solver to improve the calculation accuracy of velocities of the moving meshes.A limiter is presented for the numerical solution of the fluid part of the MHD equations and it can avoid calculating the complex eigen-system of the MHD *** numerical examples are presented to demonstrate the accuracy,non-oscillatory property and preservation of the exactly divergence-free property of our method.
Quantitative phase imaging (QPI) has emerged as method for investigating biological specimen and technical objects. However, conventional methods often suffer from shortcomings in image quality, such as the twin image...
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Quantitative phase imaging (QPI) has emerged as method for investigating biological specimen and technical objects. However, conventional methods often suffer from shortcomings in image quality, such as the twin image artifact. A novel computational framework for QPI is presented with high quality inline holographic imaging from a single intensity image. This paradigm shift is promising for advanced QPI of cells and tissues.
Diagnosis of fluids is extremely significant at high temperatures and high *** an advanced imaging technique,high-energy proton radiography has great potential for application to the diagnosis of high-density *** high...
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Diagnosis of fluids is extremely significant at high temperatures and high *** an advanced imaging technique,high-energy proton radiography has great potential for application to the diagnosis of high-density *** high-energy proton radiography,an angular collimator can control the proton flux and thus enable material diagnosis and reconstruction of *** this paper,we propose a multimaterial diagnostic method using angular *** method is verified by reconstructing the density distribution from the proton flux obtained via theoretical calculations and numerical *** simulate a 20 GeV proton imaging system using the Geant4 software toolkit and obtain the characteristic parameters of single-material *** design several concentric spherical objects to verify the *** discuss its application to detonation *** results show that this method can determine the material and boundary information about each component of a multi-material ***,it can be used to diagnose a mixed material and reconstruct densities in a detonation.
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