scholarly journals Устойчивость углеродной нанолуковицы в контакте с графитовой подложкой

2019 ◽  
Vol 45 (12) ◽  
pp. 9
Author(s):  
С.Ш. Рехвиашвили ◽  
М.М. Бухурова
Keyword(s):  
Theoretical Model ◽  
Interaction Potential ◽  
Interatomic Interaction ◽  
Continuum Approximation ◽  
Graphite Phase ◽  
Interatomic Interaction Potential ◽  
The Stability ◽  
The Continuum

AbstractA theoretical model describing the stability of a carbon nano-onion in the presence of a bulk catalytic graphite phase is constructed based on the continuum approximation of interatomic interaction potential and mechanics of deformed systems. It is shown that a carbon nano-onion becomes unstable when its radius exceeds double value of the radius of a fullerene C_60 molecule.

scholarly journals History dependence and the continuum approximation breakdown: the impact of domain growth on Turing’s instability

2017 ◽  
Vol 473 (2199) ◽  
pp. 20160744 ◽  
Author(s):  
Václav Klika ◽  
Eamonn A. Gaffney
Keyword(s):  
Domain Size ◽  
Turing Instability ◽  
Domain Growth ◽  
Continuum Approximation ◽  
Growing Domain ◽  
Spatial Frequencies ◽  
History Of ◽  
The Stability ◽  
The Impact ◽  
The Continuum

A diffusively driven instability has been hypothesized as a mechanism to drive spatial self-organization in biological systems since the seminal work of Turing. Such systems are often considered on a growing domain, but traditional theoretical studies have only treated the domain size as a bifurcation parameter, neglecting the system non-autonomy. More recently, the conditions for a diffusively driven instability on a growing domain have been determined under stringent conditions, including slow growth, a restriction on the temporal interval over which the prospect of an instability can be considered and a neglect of the impact that time evolution has on the stability properties of the homogeneous reference state from which heterogeneity emerges. Here, we firstly relax this latter assumption and observe that the conditions for the Turing instability are much more complex and depend on the history of the system in general. We proceed to relax all the above constraints, making analytical progress by focusing on specific examples. With faster growth, instabilities can grow transiently and decay, making the prediction of a prospective Turing instability much more difficult. In addition, arbitrarily high spatial frequencies can destabilize, in which case the continuum approximation is predicted to break down.

scholarly journals Расчет ядерных тормозных способностей в квазиклассическом приближении

2021 ◽  
Vol 91 (12) ◽  
pp. 1901
Author(s):  
П.Ю. Бабенко ◽  
А.Н. Зиновьев
Keyword(s):  
Angular Momentum ◽  
Interaction Potential ◽  
Semiclassical Approximation ◽  
Interatomic Interaction ◽  
Hydrogen Isotopes ◽  
Interatomic Interaction Potential ◽  
Nuclear Stopping ◽  
Additional Maximum ◽  
Good Agreement

The results of calculating nuclear stopping in the semiclassical approximation for the systems H-Be, H-C, H-W, O-C, O-Be, O-Al are presented. It was found that in the presence of a well in the interatomic interaction potential, an additional maximum appears in the dependence of the nuclear stopping on the energy of the bombarding particles. When using the universal potential without a well, this feature is absent. It is shown that by scaling the data obtained for systems with hydrogen are recalculated for collisions with the participation of hydrogen isotopes D and T. The results obtained are in good agreement with classical calculations, which is explained by the fact that large scattering angles make the main contribution to the nuclear stopping, and the applicability criterion changes to the condition: angular momentum ℓ >> 1.

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