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21.
N. T. Zung 《Regular and Chaotic Dynamics》2007,12(6):680-688
In this paper we show that, if an integrable Hamiltonian system admits a nondegenerate hyperbolic singularity then it will
satisfy the Kolmogorov condegeneracy condition near that singularity (under a mild additional condition, which is trivial
if the singularity contains a fixed point).
相似文献
22.
The aim of this paper is to extend the notion of commutativity of vector fields to the category of singular foliations using Nambu structures, i.e., integrable multi-vector fields. We will classify the relationship between singular foliations and Nambu structures and show some basic results about commuting Nambu structures. 相似文献
23.
We perform molecular dynamics (MD) simulation of diffusion in liquid GeO2 at the temperatures ranged from 3000 to 5000 K and densities ranged from 3.65 to 7.90 g/cm3. Simulations were done in a model containing 3000 particles with the new interatomic potentials for liquid and amorphous GeO2, which have weak Coulomb interaction and Morse-type short-range interaction. We found a liquid–liquid phase transition in simulated liquid GeO2 from a tetrahedral to an octahedral network structure upon compression. Moreover, such phase transition accompanied with an anomalous diffusion of particles in liquid GeO2 that the diffusion constant of both Ge and O particles strongly increases with increasing density (e.g. with increasing pressure) and it shows a maximum at the density around 4.95 g/cm3. The possible relation between anomalous diffusion of particles and structural phase transition in the system has been discussed. 相似文献
24.
V. V. Hoang H. Zung N. H.B. Trong 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2007,44(3):515-524
Structural properties of amorphous TiO2 spherical nanoparticles have
been studied in models with different sizes of 2 nm, 3 nm, 4 nm and 5 nm under
non-periodic boundary conditions. We use the pairwise interatomic potentials
proposed by Matsui and Akaogi. Models have been obtained by cooling from the
melt via molecular dynamics (MD) simulation. Structural properties of an
amorphous nanoparticle obtained at 350 K have been analyzed in detail
through the partial radial distribution functions (PRDFs), coordination
number distributions, bond-angle distributions and interatomic distances.
Moreover, we show the radial density profile in a nanoparticle. Calculations
show that size effects on structure of a model are significant and that if
the size is larger than 3 nm, amorphous TiO2 nanoparticles have a
distorted octahedral network structure with the mean coordination number
ZTi-O ≈6.0 and ZO-Ti ≈3.0 like those observed in the
bulk. Surface structure and surface energy of nanoparticles have been
obtained and presented. 相似文献
25.
N.T. Zung 《Commentarii Mathematici Helvetici》2000,75(2):271-283
We prove that, in a neighborhood of a corank-1 singularity of an analytic integrable Hamiltonian system with n degrees of freedom, there is a locally-free analytic symplectic
\Bbb Tn-1 {\Bbb T}^{n-1} -action which preserves the moment map, under some mild conditions. This result allows one to classify generic degenerate corank-one singularities of integrable Hamiltonian systems. It can also be applied to the study of (non)integrability of perturbations of integrable systems. 相似文献
26.
27.
B. T. H. L. Khanh V. V. Hoang H. Zung 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,49(3):325-332
We have investigated the microstructure of amorphous Fe2O3 nanoparticles by using molecular dynamics (MD) simulations. Non-periodic boundary conditions with Born-Mayer type pair potentials
were used to simulate a spherical model of different diameters of 2, 3, 4 and 5 nm. Structural properties of an amorphous
model obtained at 350 K have been analyzed in detail through the partial radial distribution functions (PRPFs), coordination
number distributions, bond-angle distributions and interatomic distances. Calculations showed that structural characteristics
of the model are in qualitative agreement with the experimental data. The observation of a large amount of structural defects
as the particle size is decreased suggested that surface structure strongly depends on the size of nanoparticles. In addition,
surface structure of amorphous Fe2O3 nanoparticles have been studied and compared with that observed in the core and in the bulk counterpart. Radial density profiles
and stoichiometry in morphous Fe2O3 nanoparticles were also found and discussed. 相似文献
28.
We show a natural relation between the monodromy formula for focus-focus singularities of integrable Hamiltonian systems and a formula of Duistermaat–Heckman, and extend the main results of our previous note (
1-action, monodromy, and topological classification) to the case of degenerate focus-focus singularities. We also consider the non-Hamiltonian case, local normal forms, etc. 相似文献
29.
Din' Zung 《Journal of Mathematical Sciences》1986,35(6):2859-2875
The paper deals with imbedding theorems and harmonic approximation for classes of periodic functions of several variables. Necessary and sufficient conditions for imbedding are found for various classes of smooth functions. The paper contains asymptotic estimates for fractional order derivatives of multidimensional Dirichlet and Favard kernels, for Fourier best approximation and for the Kolmogorov diameter of smooth function classes.Translated from Trudy Seminara imeni I. G. Petrovskogo, No. 10, pp. 207–226, 1984. 相似文献
30.
Nguen T'en Zung L. S. Polyakova E. N. Selivanova 《Functional Analysis and Its Applications》1993,27(3):186-196
Moscow State University. Translated from Funktsional'nyi Analiz i Ego Prilozheniya, Vol. 27, No. 3, pp. 42–56, July–September, 1993. 相似文献