971 research outputs found
Gunn Oscillators Based on Shielded Dielectric Resonators with Mechanical Frequency Tuning
The features of Gunn oscillators based on shielded dielectric resonators with whispering gallery modes and ray oscillations are investigated. Their comparative analysis for oscillators with different dielectric resonant structures is carried out
Self-Adjointness of Generalized MIC-Kepler System
We have studied the self-adjointness of generalized MIC-Kepler Hamiltonian,
obtained from the formally self-adjoint generalized MIC-Kepler Hamiltonian. We
have shown that for \tilde l=0, the system admits a 1-parameter family of
self-adjoint extensions and for \tilde l \neq 0 but \tilde l <{1/2}, it has
also a 1-parameter family of self-adjoint extensions.Comment: 11 pages, Latex, no figur
Registration of Electrons with Energies Greater than 30 Kev in the Near-lunar Space
Measured high energy electron flux in lunar environment by gas-discharge counter on lunar prob
Registration of Solar Cosmic Rays on the AMS ''luna-11''
Proton flux measurements onboard lunar prob
Vertical Structure of the Milky Way Disk with Gaia DR3
Using a complete sample of about 330,000 dwarf stars, well measured by Gaia DR3, limited to the galactic north and south solid angles (Formula presented.) and up to a vertical distance of 2 kpc, we analyze the vertical structure of the Milky Way stellar disks, based on projected tangential velocities. From selected subsamples dominated by their corresponding population, we obtain the thin and thick disk scale heights as (Formula presented.) pc and (Formula presented.) pc, respectively. Then from the simultaneous fitting of the sum of two populations over the whole sample, assuming these scale heights, we estimate the thick-to-thin disk number density ratio at the galactic plane to be (Formula presented.), which is consistent with a previous result by the authors: in the galactic plane there is a significant number of thick disk stars, possibly as many as thin disk ones, which also points to the existence of more thick disk stars than generally thought. The overall fit does not closely follow the data for (Formula presented.) pc and points to the presence of more stars beyond the thin disk that cannot be accounted for by the two-disk model
Ways to improve the confinement of fast ions in stellarators by RF waves: general analysis and application to Wendelstein 7-X
Aneurysm of internal carotid artery, which simulated paratonsillary abscess (clinical case)
This article describes a rare case of paratonsillar abscess imitation among the patients with the aneurysm of ICA. The purpose of the study is to describe the methods of this disease diagnosing using the example of a clinical case, to give a general description of this nosology occurrence frequency, and to recommend a detailed approach to the differential diagnosis among this category of patient
Double-kink fishbone instability caused by circulating energetic ions
The destabilization of double kink modes by the circulating energetic ions in tokamaks with the plasma current having an off-axis maximum is studied. It is shown that the high-frequency fishbone instability [Energetic Particle Mode (EPM)] and the low-frequency (diamagnetic) fishbones are possible for such an equilibrium, their poloidal and toroidal mode numbers being not necessarily equal to unity. A new kind of the EPM instability, ''doublet fishbones,'' is predicted. This instability is characterized by two frequencies; it can occur in a plasma with a non-monotonic radial profile of the energetic ions when the particle orbit width is less than the width of the region where the mode is localized. It is found that the diamagnetic fishbone branch exists even when the orbit width exceeds the mode width; in this case, however, the instability growth rate is relatively small
Nonequidistant two-dimensional antenna arrays are based on Latin squares for registration of cosmic, atmospheric and lithospheric radiation
The possibility of using Latin squares for constructing two-dimensional non-equidistant antenna arrays that can be used for development of radio telescopes and systems for remote sensing of atmospheric and lithospheric radiation has been shown. An algorithm for calculating the coordinates of elements of a non-equidistant antenna array using the values of elements of Latin squares is proposed. It is shown that in this case, it is possible to obtain an almost complete coverage of the grid of spatial frequencies in the region of the arrangement of the elements at small filling coefficients of array. Directional patterns are studied and the side lobes levels are estimated for non-equidistant antennas obtained on the basis of Latin squares. The possibility of synthesizing of large antenna arrays on the basis of composite squares using the embedding of generative Latin squares is shown. The characteristics of the obtained arrays are studied. It is shown that using the shifts and mutual rotations of individual layers is involved in the synthesized array; its characteristics can be substantially improved
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