Quantum Size Effects and Transport Phenomena in PbSe Quantum Wells and PbSe/EuS Superlattices

It is established that the room-temperature dependences of transport properties on the total thickness of PbSe layers d in PbSe/EuS superlattices exhibit an oscillatory behavior. It is shown that the oscillation period Δd practically coincides with the period of the thickness oscillations observed earlier in single PbSe/EuS quantum well. The non-monotonic character of these dependences is attributed to quantum size effects. The theoretically estimated and experimentally determined Δd values are in good agreement

Gebrukothuria profundus, a new genus and species of laetmogonid holothurian (Elasipodida, Laetmogonidae) from around the Crozet Plateau in the Southern Indian Ocean

A new genus and species of laetmogonid holothurian (Elasipodida, Laetmogonidae), collected from around the Crozet Plateau in the Southern Indian Ocean, is described. It differs from other members of the family in that the body wall lacks the wheel-shaped calcareous deposits completely. Instead only rods are present. The genus is also distinguished by the combination of other morphological characters lacking in other known genera: absence of circum-oral and ventrolateral papillae together with development of midventral tube feet. All other members of the family Laetmogonidae are known to have wheel-shaped deposits, therefore diagnosis of the family is refined

THE ROLE OF GENE POLYMORPHISMS ETIOPATHOGENETIC IN SCHIZOPHRENIA

In a review article summarizes the role of polymorphisms in genes etiopathogenetic schizophrenia. A convincing relationship of polymorphic variants 5-HTR2A gene and gene DRD2 with clinical heterogeneity of schizophrenia.Found that genotype A2A2 in case 5-HTR2A gene and genotype of the DRD2 gene to A2A2, and their combination is significantly more common in patients with the chronic form of schizophrenia characterized by a significant degree of negative symptoms, formerly home and hereditary burdenedness on schizophrenia. Is set to increase in relative risk for schizophrenia different severity in the presence of genotype 5-HTR2A A2A2 compared to genotype A1A1.In addition, a relationship of genotype 5-HTR2A A2A2 family form of schizophrenia. An association of DD genotype and allele D angiotenzin converting enzyme gene with schizophrenia in men. This tended to increase the frequency of the genotype (DD) in patients with schizophrenia with duration of more than 15 years. Thus, topical is the study of genetic markers of risk for schizophrenia and their use of multivariate analysis of the etiopathogenesis of the disease

"Political Economy of Empathy" in the Decembrists' Ego Documents at the Yalutorovsk Colony

The article discusses political economy discourse of ego documents related to the life and work of Decembrists at the colony in Yalutorovsk, Tobolsk Province (1832-1856). We study the Decembrists' private letters, autobiographical texts by I. D. Yakushkin, I. I. Pushchin, N. D. Fonvizina, E. P. Obolensky, as well as the memoirs written by M. S. Znamensky, O. N. Balakshina, A. P. Sozonovich, S. M. Semenov, K. M. Golodnikov etc. The subject of the research is "the political economy of empathy" discourse, expressed in the system of recurring motifs in the epistolary and autobiographical prose of the XIX century.В статье рассматривается политэкономический дискурс эго-документов, связан­ных с жизнью и деятельностью колонии ссыльных декабрстов в Ялуторовске Тобольской губернии (1832-1856)

Size effects in chlorine doped PbSe thin films

The possibility of obtaining strongly degenerate (≈ 3·10²⁰ сm⁻³) PbSe thin films (d = 5 – 220 nm) with n-type conductivity by thermal evaporation in vacuum of PbSe crystals doped with PbCl₂, with subsequent condensation onto (001) KCl substrates was established. It was shown that the films had high homogeneity degree, no grain structure was observed. The thickness dependences of thermoelectric properties (the Seebeck coefficient S, the Hall coefficient RH and the electric conductivity σ) of thin films were obtained. In the thickness range d ≈ 5 ÷ 30 nm, oscillation properties were observed with growth of d that are attributable to electron gas quantization. The calculation of S(d) dependence on the assumption of size quantization with regard to contribution of several subbands and the thickness dependence of the Fermi energy was shown to be in agreement with the experimental data. In the region of d > 30 nm there was growth of S and σ with thickness, which is attributable to manifestation of classical size effect and interpreted in the framework of Fuchs-Sondheimer and Mayer theories

Siberia in the Artistic Vision of Anna Akhmatova (the Context of A Little Geography)

Поступила в редакцию 21.05.2019. Принята к печати 21.06.2019.Submitted on 21 May, 2019. Accepted on 21 June, 2019.В статье рассматривается структура сибирского текста в поэзии и прозе Анны Ахматовой, преимущественно сложившегося в ее творчестве 1930–1940-х гг. Цель исследования — установление повторяющихся, системных признаков авторского пространства Сибири с учетом методологических принципов рассмотрения «психофизиологических» пространств, сформулированных в ряде работ В. Н. Топорова. Сибирский локус Ахматовой диалогически и полемически соотнесен с лирикой О. Мандельштама, прозой Л. Н. Толстого, поэзией ссыльных декабристов. В нем нет привычных для русской литературы «общих мест», ландшафтных деталей, место которых занимают имена собственные (топонимы, наименования лиц). Основным объектом историко-культурного комментария является стихотворение «Немного географии» («Не столицею европейской»), написанное одновременно с поэмой «Реквием» в 1937 г. В статье выявлены контекстные связи стихотворения с другими произведениями Ахматовой (поэма «Русский Трианон», «Поэма без героя» и др.), с лирикой А. И. Одоевского, с романами Л. Н. Толстого «Воскресение», «Война и мир» и др. Установлена структура перцептивного пространства в стихотворениях Ахматовой о Сибири, которая основана на подавлении зрительного восприятия и повторении ольфакторных признаков. Отказ от внешнего изображения Сибирской земли, акцент на интертекстуальном характере сенсорных мотивов позволяют предположить, что в художественной оптике Ахматовой Сибирь представлена как точка зрения на мир, как исток катастрофического сознания лирического субъекта и мотивировка пророческих форм лирического высказывания с их принципиальной незавершенностью и фрагментарностью композиции.This article examines the structure of Siberian text in Anna Akhmatova’s poetry and prose; this type of text took shape in her works in the 1930s–1940s. The purpose of this study is to establish recurrent systematic attributes of the author’s image of Siberian space relying on the methodological principles of scrutiny of “psychophysiological spaces” put forward by V. N. Toporov in some of his research. Akhmatova’s Siberian locus establishes a dialogue and debate with Osip Mandelstam’s poetry, Leo Tolstoy’s prose, and exiled Decembrists’ poetry. It does not have the usual “commonplaces” of Russian literature or landscape details; in their place, there are proper names (toponyms and people’s names). The primary object of this historical and cultural commentary is the poem A Little Geography (Not like a European Capital), written in 1937, at the same time as Requiem. This research demonstrates the poem’s context connections with other poems by Akhmatova (The Russian Trianon, Poem without a Hero, etc.), with Alexander Odoevsky’s poetry, Leo Tolstoy’s novels Resurrection and War and Peace, etc. In Akhmatova’s poetry about Siberia, the author of the article observes the structure of perceptive space which restrains the visual perception and builds on the repetition of olfactory references. The absence of a formal description of the Siberian territory and emphasis on the intertextual character of sensory motifs makes it possible to suggest that in Akhmatova’s artistic vision, Siberia is a vantage point, a source of the poet’s calamitous perception and a reason for prophetic phrasing represented in the incompleteness and fragmentariness of the composition of the poem

Dependences of thermoelectric properties on the thickness of thin films of indium doped lead telluride

Dependences of thermoelectric properties (the Seebeck coefficient S, the electric conductivity σ, the Hall coefficient RH, the carrier mobilityμ and the thermoelectric power P = S²·σ) on the thickness d (d = 10 – 255 nm) of thin films prepared by vacuum evaporation of indiumdoped PbTe crystals and subsequent condensation on (111) BaF₂ substrates were obtained. With decreasing thickness of films to d ≈ 40 nm, there is n- to p-type inversion of conduction which is related to a change in thermodynamic equilibrium conditions and partial reevaporation of lead and/or indium atoms. Extremes were found on the thickness dependences of properties at d₁ ≈ 20 nm which is indicative of hole gas quantization. In the range of thicknesses with n-type conduction there is a smooth change in thermoelectric properties with thickness which testifies to manifestation of classical size effect and is sufficiently well described in the framework of the Fuchs-Sondheimer theory

Synthesis and properties of spherical catalysts TiO2-SiO2/МхOy (M = Co and Cr)

Layered spherical materials were obtained, the inner layer of which is represented by oxides of cobalt or chromium, and external oxides of titanium and silicon. D-metals were fixed on the surface of the polymer substrate through sorption from aqueous solutions of the corresponding salts. The outer layer of the oxide titanium-silicon matrix was obtained by the sol-gel method. Aggregative stability of sols was controlled by viscosimetry. The influence of the components on the stability of sol solutions has been established. The time interval for the stability of sols is in the range of 400-1000 h. The laminated structure, material characteristics are studied using 3D-microtomography. The catalytic activity of the obtained TiO2-SiO2/Cr2O3 and TiO2-SiO2/Co3O4 samples was compared to the n-heptane oxidation reaction. The maximum heptane conversion for the TiO2-SiO2/Co3O4 sample is 80 % at a temperature of 600 °C, for the TiO2-SiO2/Cr2O3 sample, the conversion of n-heptane reaches 100 % at 400 °C

Symmetries of Electrostatic Interaction between DNA Molecules

We study a model for pair interaction $U$ of DNA molecules generated by the discrete dipole moments of base-pairs and the charges of phosphate groups, and find noncommutative group of eighth order ${\cal S}$ of symmetries that leave $U$ invariant. We classify the minima using group ${\cal S}$ and employ numerical methods for finding them. The minima may correspond to several cholesteric phases, as well as phases formed by cross-like conformations of molecules at an angle close to $\rm{90}^{o}$, "snowflake phase". The results depend on the effective charge $Q$ of the phosphate group which can be modified by the polycations or the ions of metals. The snowflake phase could exist for $Q$ above the threshold $Q_C$. Below $Q_C$ there could be several cholesteric phases. Close to $Q_C$ the snowflake phase could change into the cholesteric one at constant distance between adjacent molecules.Comment: 13 pages, 4 figure