This review is devoted to a discussion of the prospects for solving the problem of a low degree of integration of the traditional elements for promising (due to the high performance and extremely low energy dissipation) superconducting digital electronics. We define three main directions on the path to compact multi-element Josephson electronic systems: (1) reduction of the Josephson junction to submicron size, (2) decrease of the area of standard logic cells, and (3) fabrication of a compact and rapid Josephson memory. We present the physical foundations of Josephson elements in order to show the fundamental constraints on establishing standard submicron tunnel contacts and compact logic cells/memory elements. This survey clearly demonstrates the essence of breakthrough technological solutions to create ultrasmall heterostructures with desired settings, reduce and optimize logic cells, and create memory unit cells based on Josephson junctions with magnetic layers.
Show AbstractColor-magnetic thermal monopoles in $SU$(2) lattice gluodynamics with improved Simanzik action were studied. The density of the monopoles, the monopole chemical potential, the cluster susceptibility, and the cluster magnetization were studied. These results were compared with results that were reported elsewhere.
Show AbstractThe specific features of the formation of impulse acoustic and seismic signals, as well as their propagation to relatively short distances under various conditions of their excitation, based on the registration of consistent data on a pressure field and an oscillation speed field are discussed. It is shown that the “delayed” character of the signals, especially at low exit angles of projectiles, is due to the intense interaction of a wave excited by a shot with the ground and to multiple reflections of the signals. The use of signals registered by the channels of a vector receiver makes it possible to obtain information on the spatial distribution of the signals. When a projectile bursts in air, the sound wave that is incident on the land surface induces a seismoacoustic wave that is first registered by channels of a combined receiving unit (CRU).
Show AbstractThe accuracy of calculating the gravitational constant, $G$, using a method based on the numerical integration of an equation of oscillations and a method based on the nonlinear oscillation theory is analyzed. Taking account of a higher (the seventh) power at an amplitude of 80 mrad reduces the error of calculating the moment of attraction forces by 47 times. This reduces the error of calculating $G$ from 15 to 0.3 ppm.
Show AbstractTheoretical and experimental studies of the local statistical characteristics of Gaussian beams propagated through the paths with strong turbulence were carried out and their results are presented. It is ascertained that the applicability of the scintillation index meanings are substantially limited for the assessment of the performance quality of the optical data transmitting channels. On the basis of the experimental data got under different propagation conditions the peculiarities of the localized intensity distributions and those of the scintillation index are revealed.
Show AbstractFeatures of the behavior of long vertically distributed receiving systems (VDRSs) for use in the low-frequency tomography of the ocean are considered. In the most common design variant, VDRSs are structures that consist of a cable rope of up to several hundreds of meters in length with receiving modules placed coaxially (hydrophones) or axis-perpendicularly (accelerometers) on it, a buoy, and an anchor, which support the predetermined spatial position of the system. The results of the experiments carried out using VDRSs of 32 and 128 m in the White Sea are discussed. Underwater-current forces on a VDRS result in vibrations on system elements, especially on the cable-rope, which are transmitted to hydrophones and are responsible for the formation of a pseudo sound signal at frequencies below 10–12 Hz that, under certain conditions, can considerably exceed the background noise level of the water area. These facts may considerably reduce the efficiency of a VDRS and limit the frequency range of measurements from the bottom. The similarity of the results obtained by different experiments suggests that there is a general mechanism for the occurrence of vibrations and pseudo sound. The definition of such a mechanism can point the way to eliminating these undesirable effects and extending the frequency range of a VDRS into the infrasonic range.
Show AbstractWe obtained a metal-dielectric composite by thermal restoration of silver atoms from an alcohol solution of a precursor in nanoporous glass with pores with a radius of 2 nm. The concentration, size, and asphericity degree of metal nanoparticles formed in the pores are characterized according to the measured extinction spectra of the material.
Show AbstractThe concentration dependence of the short-range order parameters in gold-rich polycrystalline disordered solid gold-copper solutions was investigated using the X-ray diffuse-scattering method. On the X-ray diffuse-scattering patterns of disordered alloys with 75, 83, and 90% gold, diffuse maximums that are typical of short-range order were absent in the region of the possible superstructure reflex (100), but in the region of the possible reflex (110), an intensity rise on the scattering patterns was revealed that noticeably depended on the gold concentration. The application of the method, taking the effects of static displacements on the considered coordination spheres into account, allowed the determination of short-range order parameters for nine coordination spheres. The spectra of short-range order parameters, which was calculated using the least-squares method, had the long-range sign-alternating representation that is inherent in the Cu$_3$Au superstructure. The absolute values of short-range order parameters were detected to decrease with an increase of the gold content in the alloys. The concentration dependence and small values of ordering energy of investigated polycrystalline alloys were revealed on the first coordination sphere using the Clapp-Moss method.
Show AbstractExperimental results on the visualization of the density of states in InAs/GaSa(001) quantum dots that were obtained by tunnel atomic-force microscopy in an ultrahigh vacuum are presented. A one-dimensional (1D) model of dissipative quantum tunneling is proposed for describing experimental current-voltage characteristics of a tunnel contact between an atomic force microscope probe and the surface of InAs/GaAs (001) quantum dots. It was found that the influence of two local modes of the wide-band matrix on the probability of 1D dissipative tunneling leads to the appearance of several randomly spaced peaks in the field dependence. It was shown that the theoretical dependence agrees qualitatively with experimental the current-voltage characteristic of the atomic force microscope tip and the surface of InAs/GaAs(001) quantum dots.
Show AbstractThe structural X-ray analysis of the phase-structure state of the Pd-In-Ru alloy foil after two types of hydrogenation and relaxation (during 8200 h) was carried out. The broadening of the distibution function of the coherent scattering regions (CSRs) with respect to the concentration of indium atoms in the alloy matrix was found to be independent of the foil hydrogenation. The differences in the phase-separation processes on the opposite sides of and the orientation dependencies in the additional phase enriched by vacancies or indium atoms were revealed.
Show AbstractThe project of the scintillation complex of the upgraded Tunka-133 detector is described. Software for simulation of recording and processing of events by the future scintillation part of the Tunka-133 detector is presented. Highlights of the simulation are given. Results of the simulation of extensive air showers using Aires software are listed.
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