Nanometer-Scale Shock-Front Structure in Metals

1988 ◽  
Vol 141 ◽  
Author(s):  
Paul A. Taylor ◽  
Brian W. Dodson
Keyword(s):  
Shock Wave ◽  
Molecular Dynamics ◽  
Shock Front ◽  
Nanometer Scale ◽  
Many Body ◽  
Front Structure ◽  
Atomic Interactions ◽  
The Many ◽  
First Time ◽  
Structural Instabilities

AbstractMolecular dynamics shock wave simulations have been performed, which for the first time include a realistic many-body description of the atomic interactions. The structural instabilities observed in the shock-front structure are dramatically influenced by the many-body effects of these atomic interactions.

scholarly journals Shock-wave model of the earthquake and Poincaré quantum theorem give an insight into the aftershock physics.

2018 ◽  
Vol 62 ◽  
pp. 03006
Author(s):  
Vladimir Kuznetsov
Keyword(s):  
Shock Wave ◽  
Wave Model ◽  
Particle Systems ◽  
Many Body ◽  
Initial State ◽  
Recurrence Theorem ◽  
Shock Wave Model ◽  
Quantum Phenomena ◽  
First Time ◽  
Insight Into

A fundamentally new model of aftershocks evident from the shock-wave model of the earthquake and Poincaré Recurrence Theorem [H. Poincare, Acta Mathematica 13, 1 (1890)] is proposed here. The authors (Recurrences in an isolated quantum many-body system, Science 2018) argue that the theorem should be formulated as “Complex systems return almost exactly into their initial state”. For the first time, this recurrence theorem has been demonstrated with complex quantum multi-particle systems. Our shock-wave model of an earthquake proceeds from the quantum entanglement of protons in hydrogen bonds of lithosphere material. Clearly aftershocks are quantum phenomena which mechanism follows the recurrence theorem.

Effects of Nanoscale Voids on the Sensitivity of Model Energetic Materials

1995 ◽  
Vol 418 ◽  
Author(s):  
C. T Whitea ◽  
J. J. C. Barretta ◽  
J. W. Mintmirea ◽  
M. L. Elert ◽  
D. H. Robertson
Keyword(s):  
Shock Wave ◽  
Molecular Dynamics ◽  
Hot Spots ◽  
Energetic Materials ◽  
Theoretical Study ◽  
Atomic Scale ◽  
Nanometer Scale ◽  
Higher Temperature ◽  
Detonation Transition ◽  
Dynamics Simulations

AbstractBecause of its importance in designing safer, more reliable explosives the shock to detonation transition in condensed phase energetic materials has long been a subject of experimental and theoretical study. This transition is thought to involve local hot-spots which represent regions in the material which couple efficiently to the shock wave leading to a locally higher temperature and ultimately initiation. However, how at the atomic scale energy is transferred from the shock front into these local “hot spots” remains a key question to be answered in studies of the predetonation process. In this paper we report results of molecular dynamics simulations that suggest that even nanometer scale defects can play an important role in the shock to detonation transition.

scholarly journals Static and Dynamic Statistical Correlations in Water: Comparison of Classical Ab Initio Molecular Dynamics at Elevated Temperature With Path Integral Simulations at Ambient Temperature

2022 ◽  
Author(s):  
Chenghan Li ◽  
Francesco Paesani ◽  
Gregory A. Voth
Keyword(s):  
Molecular Dynamics ◽  
Elevated Temperature ◽  
Ambient Temperature ◽  
Ab Initio ◽  
Density Functional ◽  
Ab Initio Molecular Dynamics ◽  
Many Body ◽  
Statistical Correlations ◽  
Higher Temperature ◽  
The Many

It is a common practice in ab initio molecular dynamics (AIMD) simulations of water to use an elevated temperature to overcome the over-structuring and slow diffusion predicted by most current density functional theory (DFT) models. The simulation results obtained in this distinct thermodynamic state are then compared with experimental data at ambient temperature based on the rationale that a higher temperature effectively recovers nuclear quantum effects (NQEs) that are missing in the classical AIMD simulations. In this work, we systematically examine the foundation of this assumption for several DFT models as well as for the many-body MB-pol model. We find for the cases studied that a higher temperature does not correctly mimic NQEs at room temperature, which is especially manifest in significantly different three-molecule correlations as well as hydrogen bond dynamics. In many of these cases, the effects of NQEs are the opposite of the effects of carrying out the simulations at an elevated temperature.

GOLD DEPOSITION ON GaAs(001) SURFACES: MOLECULAR-DYNAMICS SIMULATIONS

2002 ◽  
Vol 13 (06) ◽  
pp. 759-769 ◽  
Author(s):  
ŞAKIR ERKOÇ ◽  
LYNDA AMIROUCHE ◽  
LEILA ROUAIGUIA
Keyword(s):  
Molecular Dynamics ◽  
Gold Atom ◽  
Potential Energy Function ◽  
Gold Deposition ◽  
Many Body ◽  
Atomic Interactions ◽  
Dynamics Simulations ◽  
Three Body ◽  
Body Potential ◽  
Different Characteristics

We have simulated the gold deposition on arsenic and gallium terminated GaAs(001) surfaces at low and room temperatures. It has been found that gallium terminated surface is relatively less stable in comparison to the arsenic terminated surface. On the other hand, a single gold adatom on the surface has different characteristics than full coverage gold atoms on the surface; a single gold atom diffuses into the surface at room temperature. Simulations have been performed by considering classical molecular-dynamics technique using an empirical many-body potential energy function comprising two- and three-body atomic interactions.

Self Diffusion and Activation Energy of Liquid Palladium

1997 ◽  
Vol 08 (06) ◽  
pp. 1217-1221 ◽  
Author(s):  
J. I. Akhter ◽  
K. Yaldram
Keyword(s):  
Activation Energy ◽  
Molecular Dynamics ◽  
Embedded Atom Method ◽  
Many Body ◽  
Fcc Metals ◽  
Self Diffusion ◽  
Embedded Atom ◽  
The Many ◽  
Body Potential ◽  
Self Diffusion Coefficient

Molecular dynamics studies of the temperature dependence of self diffusion coefficient of palladium has been carried out using the many body potential generated by the Embedded Atom Method of Daw and Baskes. These values as well as the results for activation energy are compared with similar results for other fcc metals.

Effect of Potential Function on Molecular Dynamics Simulation of Copper Processing

2009 ◽  
Vol 407-408 ◽  
pp. 368-371 ◽  
Author(s):  
Jia Chun Wang ◽  
Ji Min Zhang ◽  
Na Li ◽  
Yun Peng Kou
Keyword(s):  
Molecular Dynamics ◽  
Potential Function ◽  
Morse Potential ◽  
Cutting Parameters ◽  
Cutting Process ◽  
Dynamics Simulation ◽  
Many Body ◽  
Actual Material ◽  
The Many ◽  
Eam Potential

In nanometric cutting process, the actual material removal can take place at atomic level, which makes it difficult or impossible to observe the machining phenomena and measure the cutting parameters in experiments. However, it is crucial to investigate the cutting process in nanoscale. In this study, the molecular dynamics (MD) method is employed to model and simulate the process of cutting monocrystalline copper. The two-body Morse potential and the many-body EAM potential are used for the atoms interaction in the workpiece to study the effect of different potential function on the simulation results. It is found that there are no obvious differences in the chip formation between Morse and EAM potential, but the Morse potential results in higher potential energy and more chips generated in the cutting process.

Three-dimensional shock tube flows for dense gases

2007 ◽  
Vol 583 ◽  
pp. 423-442 ◽  
Author(s):  
ALBERTO GUARDONE
Keyword(s):  
Shock Wave ◽  
Shock Tube ◽  
Shock Front ◽  
Numerical Simulations ◽  
Three Dimensional ◽  
Dense Gas ◽  
Complex Flow ◽  
The Many ◽  
The One ◽  
Rarefaction Shock

The formation process of a non-classical rarefaction shock wave in dense gas shock tubes is investigated by means of numerical simulations. To this purpose, a novel numerical scheme for the solution of the Euler equations under non-ideal thermodynamics is presented, and applied for the first time to the simulation of non-classical fully three-dimensional flows. Numerical simulations are carried out to study the complex flow field resulting from the partial burst of the shock tube diaphragm, a situation that has been observed in preliminary trials of a dense gas shock tube experiment. Beyond the many similarities with the corresponding classical flow, the non-classical wave field is characterized by the occurrence of anomalous compression isentropic waves and rarefaction shocks propagating past the leading rarefaction shock front. Negative mass flow through the rarefaction shock wave results in a limited interaction with the contact surface close to the diaphragm, a peculiarity of the non-classical regime. The geometrical asymmetry does not prevent the formation of a single rarefaction shock front, though the pressure difference across the rarefaction wave is predicted to be weaker than the one which would be obtained by the complete burst of the diaphragm.

scholarly journals Dynamics, morphogenesis and convergence of evolutionary quantum Prisoner's Dilemma games on networks

2016 ◽  
Vol 472 (2186) ◽  
pp. 20150280 ◽  
Author(s):  
Angsheng Li ◽  
Xi Yong
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
Nash Equilibrium ◽  
Prisoner's Dilemma ◽  
Natural Extension ◽  
Prisoner’S Dilemma ◽  
Evolutionary Games ◽  
Many Body ◽  
The Many ◽  
First Time

The authors proposed a quantum Prisoner's Dilemma (PD) game as a natural extension of the classic PD game to resolve the dilemma. Here, we establish a new Nash equilibrium principle of the game, propose the notion of convergence and discover the convergence and phase-transition phenomena of the evolutionary games on networks. We investigate the many-body extension of the game or evolutionary games in networks. For homogeneous networks, we show that entanglement guarantees a quick convergence of super cooperation, that there is a phase transition from the convergence of defection to the convergence of super cooperation, and that the threshold for the phase transitions is principally determined by the Nash equilibrium principle of the game, with an accompanying perturbation by the variations of structures of networks. For heterogeneous networks, we show that the equilibrium frequencies of super-cooperators are divergent, that entanglement guarantees emergence of super-cooperation and that there is a phase transition of the emergence with the threshold determined by the Nash equilibrium principle, accompanied by a perturbation by the variations of structures of networks. Our results explore systematically, for the first time, the dynamics, morphogenesis and convergence of evolutionary games in interacting and competing systems.

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