Calculations of exchange interaction in impurity band of two-dimensional semiconductors with out of plane impurities

We calculate the singlet-triplet splitting for a couple of two-dimensional electrons in the potential of two positively charged impurities which are located out of plane. We consider different relations between vertical distances of impurities $h_1$ and $h_2$ and their lateral distance $R$. Such a system has never been studied in atomic physics but the methods, worked out for regular two-atomic molecules and helium atom, have been found to be useful. Analytical expressions for several different limiting configurations of impurities are obtained an interpolated formula for intermediate range of parameters is proposed. The $R$-dependence of the splitting is shown to become weaker with increasing $h_1,h_2$.Comment: 14 pages, RevTeX, 5 figures. Submitted to Phys Rev.

Second Josephson excitations beyond mean field as a toy model for thermal pressure: exact quantum dynamics and the quantum phase model

A simple four-mode Bose-Hubbard model with intrinsic time scale separation can be considered as a paradigm for mesoscopic quantum systems in thermal contact. In our previous work we showed that in addition to coherent particle exchange, a novel slow collective excitation can be identified by a series of Holstein-Primakoff transformations. This resonant energy exchange mode is not predicted by linear Bogoliubov theory, and its frequency is sensitive to interactions among Bogoliubov quasi-particles; it may be referred to as a second Josephson oscillation, in analogy to the second sound mode of liquid Helium II. In this paper we will explore this system beyond the Gross-Pitaevskii mean field regime. We directly compare the classical mean field dynamics to the exact full quantum many-particle dynamics and show good agreement over a large range of the system parameters. The second Josephson frequency becomes imaginary for stronger interactions, however, indicating dynamical instability of the symmetric state. By means of a generalized quantum phase model for the full four-mode system, we then show that, in this regime, high-energy Bogoliubov quasiparticles tend to accumulate in one pair of sites, while the actual particles preferentially occupy the opposite pair. We interpret this as a simple model for thermal pressure

Loneliness as one of the stress factors of the penitentiary system

he article is devoted to the problem of the phenomenon of prison loneliness. The relevance of this study is due to the fact that the phenomenon of prison loneliness underlies penitentiary stress, as a complex psychophysiological reaction of the body to being in a penitentiary space. One of the functions of the execution of punishment as a response of society to the unlawful actions of a criminal is punishment for a committed crime, which acts in the form of induction of mental suffering of a person as a result of his artificial separation from the usual social environment, the creation of prison loneliness. At the same time, the effect of transferring suffering from the body of the criminal to his soul, noted by M. Foucault, is realized. The purpose of the work involves the analysis of the phenomenon of loneliness in the conditions of places of deprivation of liberty. The main characteristic features of prison loneliness are described. It is shown that the punishment of a criminal by imprisonment, his forcible isolation from the mainstream society is based on the mechanism of creating artificial prison deprivation. It is noted that one of the attributes of punishing a criminal is the intentional creation of a special type of loneliness — prison, causing a high level of penitentiary stress. The article shows that two types of prison loneliness can be considered. The first one is proposed to be called “physical loneliness”, which is created by the physical isolation of the convict. At the heart of the generation of suffering of the personality of this type of loneliness is the effect of a violation of the human need inherent at the gene level to communicate with other members of society. This type of prison loneliness leads to a change in the psyche of the prisoner, the loss of communication skills, his slow emotional and mental degradation. The second type of prison loneliness (loneliness in the crowd) is characterized by the fact that in conditions of prison isolation, the prisoner is almost never left alone and is constantly under the influence of carriers of the penitentiary subculture, which has a powerful negative impact on the personality of the person serving the sentence. In an environment where interests are reduced to the satisfaction of vital needs, and interpersonal aggression is the norm of behavior, negative emotions prevail in the prisoner’s sense of self, the dominant of which will be a feeling of loneliness

Methodology of designing an air cascade separator

The calculation technique of industrial cascade separators based on experimental and analytical research process methods for air fractionation of bulk materials is considered. The main technological factors and process defining parameters used in calculation of separator design are presented. It is shown that for the design of an industrial separator, it is necessary to find a relationship between the initial granulometric distribution and the fractional requirements for the finished product from the concentration of the material flow and the air flow velocity to the complete cross-section of the separator. The experiment results of material flow concentration influence on division efficiency for various cascade separator constructions are given. Mathematical relationship of the air flow rate through the apparatus on the separation boundary and bulk concentration is proposed. The correlation of these parameters with the constructive sizes of the separator is shown. The initial particle size distribution of bulk, the set restrictions for fractional characteristics of the received powder and the approximating equations of fractional extraction function of fineness narrow classes in a large or small product based on experimental data are used for calculation of the equipment. © Published under licence by IOP Publishing Ltd

Prison subculture in the context of the dialectic triad

The article contains the experience of socio-philosophical analysis of the prison subculture phenomenon. The relevance of this study is due to the transformation of the basic culture of society traditional values under the influence of the criminal subculture, the development of its new socio-cultural spaces, observed in recent decades. The aim of the work is to analyze the evolution of the prison subculture from the perspective of its interaction with the culture of society in the context of the dialectical triad «thesis-antithesis-synthesis». The definition and the main characteristic features of the prison subculture are given. The main stages of its evolution are considered in the context of interaction with the basic culture of Russian society. It is shown that the main factors influencing the metamorphosis of the prison subculture are: the high number of convicts, the presence of passionarity in the Soviet penitentiary system, the detachment system of containing convicts, the unsuccessful results of the experiment carried out in the 60s of the twentieth century to reform the penal system, negative consequences economic and social reforms of the 90s. It is noted that as a result of long-term cultural genesis, the prison subculture has the following characteristics : 1) a rigid hierarchy of the social structure of the prison community with the existence of strata of «outcasts» 2) the presence of a developed system of prison mythology, customs, symbols and taboos 3) the presence of a «control center» as the group «Thieves in law», as well as channels of information transmission 4) high adaptability of the penitentiary subculture to external conditions 5) the presence of a catchy and attractive «thieves ‘ro¬mance» and «thieves’ ideology» 6) the ability of the prison subculture to reproduce itself 7) a high degree of cohesion of prison carriers subcultures 8) the spread of the norms of the prison subculture to the majority of the population of correctional institutions. In the development of the prison subculture, the authors have identified two cycles («big» and «small»). The «big cycle» describes the global relationship between the prison subculture and the basic culture of Russian society, «small» – the interaction of collectives of convicts and staff of correctional institutions influenced by the prison subculture. In both cycles, three stages of development are distinguished, characteristic of the dialec¬tical triad. The practical significance of the work lies in comprehending the ongoing changes with the subsequent adoption of managerial decisions aimed at leveling the spread of the norms of the prison subculture in society

Oscillons: an encounter with dynamical chaos in 1953?

We present evidences that Ben F. Laposky (1914-2000) might have been the first person who created a family of nonlinear analog circuits that allowed him to observe chaotic attractors and other trademarks of nonlinear science as early as 1953.Comment: accepted to Chao

Investigation of LiFeAs by means of "Break-junction" Technique

In our tunneling investigation using Andreev superconductor - normal metal - superconductor contacts on LiFeAs single crystals we observed two reproducible independent subharmonic gap structures at dynamic conductance characteristics. From these results, we can derive the energy of the large superconducting gap $\Delta_L=(2.5 \div 3.4)$ meV and the small gap $\Delta_L=(0.9 \div 1)$ meV at $T = 4.2$ K for the $T_C^{local} \approx (10.5 \div 14)$ K (the contact area critical temperature which deviation causes the variation of $\Delta_L$). The BCS-ratio is found to be $2\Delta_L/k_BT_C = (4.6 \div 5.6)$, whereas $2\Delta_S/k_BT_C \ll 3.52$ results from induced superconductivity in the bands with the small gap.Comment: 7 pages, 5 figures. Published in Pis'ma v ZhETF 95, 604-610 (2012

Two-dimensional quantum interference contributions to the magnetoresistance of Nd{2-x}Ce{x}CuO{4-d} single crystals

The 2D weak localization effects at low temperatures T = (0.2-4.2)K have been investigated in nonsuperconducting sample Nd{1.88}Ce{0.12}CuO{4-d} and in the normal state of the superconducting sample Nd{1.82}Ce{0.18}CuO{4-d} for B>B_c2. The phase coherence time and the effective thickness $d$ of a conducting CuO_2 layer have been estimated by the fitting of 2D weak localization theory expressions to the magnetoresistivity data for the normal to plane and the in-plane magnetic fields.Comment: 5 pages, 4 postscript figure

Giant crystals inside mitochondria of equine chondrocytes

The present study reports for the first time the presence of giant crystals in mitochondria of equine chondrocytes. These structures show dark contrast in TEM images as well as a granular substructure of regularly aligned 12 nm small units. Different zone axes of the crystalline structure were analysed by means of Fourier transformation of lattice-resolution TEM images proving the crystalline nature of the structure. Elemental analysis reveals a high content of nitrogen referring to protein. The outer shape of the crystals is geometrical with an up to hexagonal profile in cross sections. It is elongated, spanning a length of several micrometres through the whole cell. In some chondrocytes, several crystals were found, sometimes combined in a single mitochondrion. Crystals were preferentially aligned along the long axis of the cells, thus appearing in the same orientation as the chondrocytes in the tissue. Although no similar structures have been found in the cartilage of any other species investigated, they have been found in cartilage repair tissue formed within a mechanically stimulated equine chondrocyte construct. Crystals were mainly located in superficial regions of cartilage, especially in joint regions of well-developed superficial layers, more often in yearlings than in adult horses. These results indicate that intramitochondrial crystals are related to the high mechanical stress in the horse joint and potentially also to the increased metabolic activity of immature individuals.(VLID)353386