Consistency of Term <i>star</i>: a Statistical Analysis of the Productive Types of System Relations with Related Terminological Units

The article is devoted to the study of the term as a system unit in its interconnections with contiguous linguistic facts on the example of semantic relations existing in the term star in the field of scientific knowledge “astrophysics”. The study is based on an analysis of the systemic correlation of units in the field of astrophysics. The authors focus on terms representing various categories of concepts in accordance with the nature of the referents they represent. The most and least productive semantic relations are established and analyzed with related first-order terms presented in the definition and second-order terms, the relations with which are represented in the texts of scientific publications outside of the definitions. The categorical pertaining of related terms with which the term star has a systemic relationship is also determined in the study. Using a statistical analysis of a selection of terms in the field of “astrophysics”, we found that the most productive semantic relationships for them are relationships such as generic, attribution, and “part-whole”

Static Polycode Text Modeling Using Network Analysis (Demotivator Dedicated to Problems of Self-Isolation)

The features of modeling a graphic-verbal polycode text, including a static image and an accompanying inscription, are considered. The study was conducted on the example of a demotivator dedicated to the problems of mass self-isolation at the very beginning of the pandemic and the introduction of restrictive measures. Significant semantic components, represented as part of only the iconic component, only the verbal component, and also as part of the verbal and iconic components at the same time are established. The semantic relations between the selected semantic components are revealed, the types of these links, revealing the different nature of their correlation are determined. On the basis of the data obtained, a network model of the considered static polycode text in the form of a semantic network was built. Cases of semantic components correlation are considered, reflecting the generally objective aspects of the situation and unrealistic ideas based on irony and hyperbole to create a comic effect. Based on quantitative analysis, representative semantic relations were established: “partitive”, “localization (in)”, “attributive”, “subject-object”. Non-representative semantic relations between the semantic components in the analyzed polycode text are revealed: “coincidence”, “localization (on)”, “temporal”, “subject-instrument”, “subject-result”

Addition Spectra of Chaotic Quantum Dots: Interplay between Interactions and Geometry

We investigate the influence of interactions and geometry on ground states of clean chaotic quantum dots using the self-consistent Hartree-Fock method. We find two distinct regimes of interaction strength: While capacitive energy fluctuations $\delta \chi$ follow approximately a random matrix prediction for weak interactions, there is a crossover to a regime where $\delta \chi$ is strongly enhanced and scales roughly with interaction strength. This enhancement is related to the rearrangement of charges into ordered states near the dot edge. This effect is non-universal depending on dot shape and size. It may provide additional insight into recent experiments on statistics of Coulomb blockade peak spacings.Comment: 4 pages, final version to appear in Phys. Rev. Let

Adaptive response and enlargement of dynamic range

Many membrane channels and receptors exhibit adaptive, or desensitized, response to a strong sustained input stimulus, often supported by protein activity-dependent inactivation. Adaptive response is thought to be related to various cellular functions such as homeostasis and enlargement of dynamic range by background compensation. Here we study the quantitative relation between adaptive response and background compensation within a modeling framework. We show that any particular type of adaptive response is neither sufficient nor necessary for adaptive enlargement of dynamic range. In particular a precise adaptive response, where system activity is maintained at a constant level at steady state, does not ensure a large dynamic range neither in input signal nor in system output. A general mechanism for input dynamic range enlargement can come about from the activity-dependent modulation of protein responsiveness by multiple biochemical modification, regardless of the type of adaptive response it induces. Therefore hierarchical biochemical processes such as methylation and phosphorylation are natural candidates to induce this property in signaling systems.Comment: Corrected typos, minor text revision

Coulomb Drag of Edge Excitations in the Chern-Simons Theory of the Fractional Quantum Hall Effect

Long range Coulomb interaction between the edges of a Hall bar changes the nature of the gapless edge excitations. Instead of independent modes propagating in opposite directions on each edge as expected for a short range interaction one finds elementary excitations living simultaneously on both edges, i.e. composed of correlated density waves propagating in the same direction on opposite edges. We discuss the microscopic features of this Coulomb drag of excitations in the fractional quantum Hall regime within the framework of the bosonic Chern-Simons Landau-Ginzburg theory. The dispersion law of these novel excitations is non linear and depends on the distance between the edges as well as on the current that flows through the sample. The latter dependence indicates a possibility of parametric excitation of these modes. The bulk distributions of the density and currents of the edge excitations differ significantly for short and long range interactions.Comment: 11 pages, REVTEX, 2 uuencoded postscript figure

Quantum and frustration effects on fluctuations of the inverse compressibility in two-dimensional Coulomb glasses

We consider interacting electrons in a two-dimensional quantum Coulomb glass and investigate by means of the Hartree-Fock approximation the combined effects of the electron-electron interaction and the transverse magnetic field on fluctuations of the inverse compressibility. Preceding systematic study of the system in the absence of the magnetic field identifies the source of the fluctuations, interplay of disorder and interaction, and effects of hopping. Revealed in sufficiently clean samples with strong interactions is an unusual right-biased distribution of the inverse compressibility, which is neither of the Gaussian nor of the Wigner-Dyson type. While in most cases weak magnetic fields tend to suppress fluctuations, in relatively clean samples with weak interactions fluctuations are found to grow with the magnetic field. This is attributed to the localization properties of the electron states, which may be measured by the participation ratio and the inverse participation number. It is also observed that at the frustration where the Fermi level is degenerate, localization or modulation of electrons is enhanced, raising fluctuations. Strong frustration in general suppresses effects of the interaction on the inverse compressibility and on the configuration of electrons.Comment: 15 pages, 18 figures, To appear in Phys. Rev.

Inelastic semiclassical Coulomb scattering

We present a semiclassical S-matrix study of inelastic collinear electron-hydrogen scattering. A simple way to extract all necessary information from the deflection function alone without having to compute the stability matrix is described. This includes the determination of the relevant Maslov indices. Results of singlet and triplet cross sections for excitation and ionization are reported. The different levels of approximation -- classical, semiclassical, and uniform semiclassical -- are compared among each other and to the full quantum result.Comment: 9 figure

Mesoscopic fluctuations of the ground state spin of a small metal particle

We study the statistical distribution of the ground state spin for an ensemble of small metallic grains, using a random-matrix toy model. Using the Hartree Fock approximation, we find that already for interaction strengths well below the Stoner criterion there is an appreciable probability that the ground state has a finite, nonzero spin. Possible relations to experiments are discussed.Comment: 4 pages, RevTeX; 1 figure included with eps

Theories for multiple resonances

Two microscopic theories for multiple resonances in nuclei are compared, n-particle-hole RPA and quantized Time-Dependent Hartree-Fock (TDHF). The Lipkin-Meshkov-Glick model is used as test case. We find that quantized TDHF is superior in many respects, except for very small systems.Comment: 14 Pages, 3 figures available upon request