208 research outputs found
Dimension on Discrete Spaces
In this paper we develop some combinatorial models for continuous spaces. In
this spirit we study the approximations of continuous spaces by graphs,
molecular spaces and coordinate matrices. We define the dimension on a discrete
space by means of axioms, and the axioms are based on an obvious geometrical
background. This work presents some discrete models of n-dimensional Euclidean
spaces, n-dimensional spheres, a torus and a projective plane. It explains how
to construct new discrete spaces and describes in this connection several
three-dimensional closed surfaces with some topological singularities
It also analyzes the topology of (3+1)-spacetime. We are also discussing the
question by R. Sorkin [19] about how to derive the system of simplicial
complexes from a system of open covering of a topological space S.Comment: 16 pages, 8 figures, Latex. Figures are not included, available from
the author upon request. Preprint SU-GP-93/1-1. To appear in "International
Journal of Theoretical Physics
Phase transformation B1 to B2 in TiC, TiN, ZrC and ZrN under pressure
Phase stability of various phases of MX (M = Ti, Zr; X = C, N) at equilibrium
and under pressure is examined based on first-principles calculations of the
electronic and phonon structures. The results reveal that all B1 (NaCl-type) MX
structures undergo a phase transition to the B2-structures under high pressure
in agreement with the previous total-energy calculations. The B1-MX structures
are dynamically stable under very high pressure (210-570 GPa). The
pressure-induced B2 (CsCl-type) MC phases are dynamically unstable even at high
pressures, and TiN and ZrN are found to crystallize with the B2-structure only
at pressures above 55 GPa. The first-order B1-to-B2 phase transition in these
nitrides is not related to the softening of phonon modes, and the dynamical
instability of B2-MX is associated with a high density of states at the Fermi
level.Comment: 9 pages, 4 figure
Training as a method of future psychologists’ moral values development
The article has the definition of moral values and moral values development (besides for better understanding of this definition we have analysed such notions as morality, values, development, values development).We have examined fundamental moral values of future psychologists and we describe the methods of training as a way of moral values development.В статье дается определение таким понятиям, как моральные ценности и развитие моральных ценностей (кроме того, для лучшего понимания сути данных понятий мы рассмотрели такие понятия: мораль, ценности, развитие, ценностное развитие). Также коротко рассматриваются основные моральные ценности будущих психологов и описываются методы тренинга как способа развития моральных ценностей
Cosmological scalar fields that mimic the cosmological model
We look for cosmologies with a scalar field (dark energy without cosmological
constant), which mimic the standard cosmological model yielding
exactly the same large-scale geometry described by the evolution of the Hubble
parameter (i.e. photometric distance and angular diameter distance as functions
on ). Asymptotic behavior of the field solutions is studied in the case of
spatially flat Universe with pressureless matter and separable scalar field
Lagrangians (power-law kinetic term + power-law potential). Exact analytic
solutions are found in some special cases. A number of models have the field
solutions with infinite behavior in the past or even singular behavior at
finite redshifts. We point out that introduction of the cosmological scalar
field involves some degeneracy leading to lower precision in determination of
. To remove this degeneracy additional information is needed beyond
the data on large-scale geometry.Comment: VIII International Conference "Relativistic Astrophysics, Gravitation
and Cosmology": May 21-23, 2008, Kyiv, Ukrain
Improving the assay-gravimetric method for determining the content of noble metals
The study considers the current state and problems of analytical control as the most important component of all stages of technology and production of noble metals. Based on the analysis carried out, a universal method for measuring the mass fraction of gold and silver in ores, products of their enrichment and metallurgical processing by the assay-gravimetric method was improved, and the optimal parameters for determining gold and silver were determined
Breeding value of potato hybrid clones from the VIR collection revealed in the environments of Kamchatka Territory
Background. Potato breeding involves planned artificial hybridization between previously selected parental lines. A way to make potato breeding more efficient is to use the diversity of the germplasm and broaden the gene pool of parental lines. Interspecific potato hybrids originated on the elite potato germplasm display a set of valuable traits. The current challenge is to assess the performance of potato hybrids under specific soil and climate conditions to clarify their breeding value.The objective of the study was to evaluate potato hybrids in the environments of Kamchatka Territory according to a set of traits, identify the best parental lines, develop new hybrid combinations, and select promising breeding material.Materials and methods. Eleven potato hybrids from VIR were studied over three years (2020–2022) in the fields of Kamchatka Research Institute of Agriculture. The hybrids were benchmarked against two reference potato cultivars, ‘Fresco’ and ‘Vulkan’, belonging to the early and mid-early maturity groups, respectively. Crosses between the hybrids and 28 potato cultivars were carried out in the greenhouse. The new hybrid material was tested in a preliminary trial nursery for yield and earliness.Results. Hybrid 117-2 was better in yield (899 g/plant) than cvs. ‘Vulkan’ and ‘Fresco’ (700–739 g/plant). Hybrids 94-5, 99-10- 1, 8-1-2004, 8-3-2004, 8-5-2004, 135-3-2005, 135-5-2005, 99-6-6, and 134-2-2006 in most traits matched the potato cultivars, manifesting good berry formation and seed setting when crossed. Out of 140 crosses between 11 hybrids and 28 cultivars, 35 crosses between 10 hybrids and 13 cultivars were successful. Most hybrids were effectively used in crossings as maternal forms.Conclusion. VIR’s hybrids 94-5, 8-1-2004, and 8-5-2004 proved the most promising as source material for the development of new early potatoes under the conditions of Kamchatka Territory
Percolation in Models of Thin Film Depositions
We have studied the percolation behaviour of deposits for different
(2+1)-dimensional models of surface layer formation. The mixed model of
deposition was used, where particles were deposited selectively according to
the random (RD) and ballistic (BD) deposition rules. In the mixed one-component
models with deposition of only conducting particles, the mean height of the
percolation layer (measured in monolayers) grows continuously from 0.89832 for
the pure RD model to 2.605 for the pure RD model, but the percolation
transition belong to the same universality class, as in the 2- dimensional
random percolation problem. In two- component models with deposition of
conducting and isolating particles, the percolation layer height approaches
infinity as concentration of the isolating particles becomes higher than some
critical value. The crossover from 2d to 3d percolation was observed with
increase of the percolation layer height.Comment: 4 pages, 5 figure
Gravitational Ionization: A Chaotic Net in the Kepler System
The long term nonlinear dynamics of a Keplerian binary system under the
combined influences of gravitational radiation damping and external tidal
perturbations is analyzed. Gravitational radiation reaction leads the binary
system towards eventual collapse, while the external periodic perturbations
could lead to the ionization of the system via Arnold diffusion. When these two
opposing tendencies nearly balance each other, interesting chaotic behavior
occurs that is briefly studied in this paper. It is possible to show that
periodic orbits can exist in this system for sufficiently small damping.
Moreover, we employ the method of averaging to investigate the phenomenon of
capture into resonance.Comment: REVTEX Style, Submitte
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