1,175 research outputs found
Exact equation for classical many-particle systems in closed form: from mechanics to statistical thermodynamics
The exact equations of motion for microscopic density of classical particles
number with account of inter-particle interactions and external field in closed
form are derived. An integral equation for equilibrium distributions of the
particles is deduced. No statistical or probabilistic hypotheses and assumption
in these deductions have been used. Some well known results of equilibrium
statistical mechanics are deduced from the obtained equations as simple
limiting cases. The wave equation for almost homogeneous systems with
inter-particle interactions are obtained. Connection between inter-particle
potential and dispersion law of sound is established.
Keywords: Many-body systems dynamics; inter-atomic potentials; phase
equilibrium
PACS 05.20.-y; 05.10.-a; 05.70.LnComment: 7 page
Irreversibility in two-body system. Toy model
It is shown that the irreversible behavior of classical systems of
interacting particles is a common property for both few-body and many-body
systems. It is due to the delay in the interactions between the particles.
PACS: 45.50.Jf Few- and many-body systems; 82.40.Bj Oscillations, chaos, and
bifurcations; 05.70.-a Thermodynamics.
Keywords: irreversibility, interactions retardation.Comment: 7 pages, 1 figur
On physical principles and mathematical mechanisms of the phenomenon of irreversibility
It is shown that the phenomenon of irreversibility in many-body and few-body
systems can be explained and described within the framework of the concept of
direct (not instantaneous) interaction of particles without using probabilistic
hypotheses. The exact solution of the model of a two-particle classical
oscillator with retarded interaction between particles is presented. It is
established that the interactions retardation leads to appearance of an
infinite spectrum of both stationary and non-stationary oscillations, and to
non-invariance of the solution with respect to time reversal as well.Comment: 12 pages, 1 figure. arXiv admin note: substantial text overlap with
arXiv:1712.0005
Exact closed probability-free kinetic equation for system of classical particles with retarded interactions: towards microscopic foundation of kinetics
The exact closed equation of motion for microscopic distribution function of
classical many-body system with account of interactions retardation between
particles is derived. It is shown that interactions retardation leads to
irreversible behaviour of many-body systems.
PACS: 05.20.Dd ; 05.60.-k; 45.20.-dComment: 5 pages, 21 ref
Relativistic kinetic theory of classical systems of charged particles: towards the microscopic foundation of thermodynamics and kinetics
In the complete system of equations of evolution of the classical system of
charges and the electromagnetic field generated by them, the field variables
are excluded. An exact closed relativistic non-Hamiltonian system of nonlocal
kinetic equations, that describes the evolution of a system of charges in terms
of their microscopic distribution functions, is obtained . The solutions of
this system of equations are non-invariant with respect to time reversal, and
also have the property of hereditarity.Comment: 19 pages, 50 reference
A fast algorithm of coexisting phases compositions calculation in binary systems
A simple fast algorithm of the conodes calculation in binary systems is
proposed. The method is based on exact solution of the problem on common
tangent to pair of approximating parabolas. Sequence of approximating parabolas
pairs having second order tangency points on separated concave parts of free
energy isotherm is generated. The sequences of the tangency points pairs
conodes with approximating parabolas converge to equilibrium compositions of
phases in binary systems.
PACS: 64.75.-g; 64.10.+h; 05.70.Ce; 82.60.-s
Key words: Phase equilibria; Free energy; Binary systems; Conode; Phase
diagrams.Comment: 10 pages, 4 figure
Low- and high-temperature anomalies in the physical properties of solid methane
Near 20.48K and in the temperature range 60--70K, anomalous behavior of
thermodynamic, spectral, plastic, elastic and other properties of solid methane
is observed. The anomalies in the vicinity of 20.48K are due to the phase
transition. Anomalies in a relatively wide range of 60--70K are
shown to be related to the essentially quantum nature of the collective
rotation of methane molecules. The provided analysis of the high-temperature
anomalies encompasses a more extensive set of phenomena in comparison with the
low-temperature ones.
Key words: solid methane, anomalies of physical properties, phase transition,
rotational temperature, quantum-classical transition.Comment: 12 pages, 16 figures, 18 reference
Generalized Lattice Model of Multi-Component Systems with Internal Degrees of Freedom. II. Quasiequilibrium States
The paper contains an application of the generalized lattice model to
multicomponent systems with internal degrees of freedom. The short-range
inter-atomic repulsions and smooth long-range parts of the inter-atomic
potentials are considered separately by means of packing condition and in
effective field approximation, respectively. The dependence of the inter-atomic
potentials on the internal degrees of freedoms (such as atomic electric and/or
magnetic momentum) taken into account. The Helmholtz free energy functional in
the generalized lattice model is reduced to the
Ginzburg-Landau-Cahn-Hilliard-like form. The connection between the
inter-atomic potentials characteristics and the parameters of the GLCH-like
functional is obtained. Equations for both equilibrium and quasi-equilibrium
states in condensed systems are derived. It is shown that equilibrium
distribution of the fast internal degrees of freedom by frozen space
distribution of the components obeys to the Schroedinger-like equation.Comment: 12 page
Modeling of hysteresis phenomena in crystalline ferroelectrics: hysteresis loops shape control by means of electric field parameters
Description of domains switching processes in crystalline ferroelectrics by
means of relaxation type equations with account of variable external electric
field is proposed. Exact solution of these equations in closed analytical form
at arbitrary dependence of electric field on time is obtained. A connection
between frequency of sinusoidal external field and hysteresis loops shapes is
analysed by numerical way. The calculation results are in qualitative
accordance with experimental data.
PACS: 77.80.Fm, 77.80.Dj, 77.80.-e
Keywords: ferroelectrics, switching process, hysteresis, polarizationComment: 10 pages, 2 figure
Low-frequency internal friction (LFIF) as express-method for identification of cryocrystals in pores of the solids
We show that studying of low-frequency internal friction (LFIF) of solid
samples at low temperatures allows determining the presence of various gases
absorbed, for some reasons, in pores and caverns of the solids. The gases come
over to a solid state (cryocrystals) and exist in the pores under corresponding
thermodynamic conditions giving an additional contribution to the LFIF spectra.
The spectra reflect the special points of the gases (temperatures of melting or
phase transitions). This information gives a real opportunity for
identification of gas in the matrix, i.e. the studied solids. This may be of
great importance for investigations of cosmic or geological samples, for
instance, asteroids, meteorites, rock formations, etc. The LFIF method allows
identification of gas media surrounding the studied sample.Comment: 14 pages, 8 figures, 39 ref
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