STUDY OF LAKES MORPHOMETRY IN THE BORDERS OF PLEISTOCENE GLACIATIONS OF THE NORTHWEST RUSSIA

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Domain wall conduction in multiaxial ferroelectrics

The conductance of domain wall structures consisting of either stripes or cylindrical domains in multi-axial ferroelectric-semiconductors is analyzed. The effects of the domain size, wall tilt and curvature, on charge accumulation, are analyzed using the Landau-Ginsburg Devonshire (LGD) theory for polarization combined with Poisson equation for charge distributions. Both the classical ferroelectric parameters including expansion coefficients in 2-4-6 Landau potential and gradient terms, as well as flexoelectric coupling, inhomogeneous elastic strains and electrostriction are included in the present analysis. Spatial distributions of the ionized donors, free electrons and holes were found self-consistently using the effective mass approximation for the respective densities of states. The proximity and size effect of the electron and donor accumulation/depletion by thin stripe domains and cylindrical nanodomains are revealed. In contrast to thick domain stripes and thicker cylindrical domains, in which the carrier accumulation (and so the static conductivity) sharply increases at the domain walls only, small nanodomains of radius less then 5-10 correlation length appeared conducting across entire cross-section. Implications of such conductive nanosized channels may be promising for nanoelectronics.Comment: 39 pages, 11 figures, 3 tables, 4 appendice

Paleolimnological studies in Russian northern Eurasia: A review

© 2017, Pleiades Publishing, Ltd. This article presents a review of the current data on the level of paleolimnological knowledge about lakes in the Russian part of the northern Eurasia. The results of investigation of the northwestern European part of Russia as the best paleolimnologically studied sector of the Russian north is presented in detail. The conditions of lacustrine sedimentation at the boundary between the Late Pleistocene and Holocene and the role of different external factors in formation of their chemical composition, including active volcanic activity and possible large meteorite impacts, are also discussed. The results of major paleoclimatic and paleoecological reconstructions in northern Siberia are presented. Particular attention is given to the databases of abiotic and biotic parameters of lake ecosystems as an important basis for quantitative reconstructions of climatic and ecological changes in the Late Pleistocene and Holocene. Keywords: paleolimnology, lakes, bottom sediments, northern

КЛАССИФИКАЦИЯ ДИСКОВЫХ СОШНИКОВ ПО ТЕХНОЛОГИЧЕСКИМ И КОНСТРУКТИВНЫМ ПАРАМЕТРАМ

When cultivating agricultural crops, pre-sowing tillage and sowing are of primary importance. The quality of these operations is determined by the choice of technological means and technical condition, adjustment and alignment, as well as compliance with all the agrotechnical requirements. Nowadays foreign and local seeding machines are often equipped with disc combined coulters. These units allow to combine operations of soil preparation, intrasoil application of initial dose of phosphorus fertilizers and sowing of agricultural crops. This article presents structural and morphological classification of coulters in 2 basic, 12 constructive and 6 engineering features. Application of this classification table is presented for description of purpose and characteristics of sowing operating units, as well as formation of digital indication record for them. The possibility of reproducing digital information about seeding operating unit in the form of variety of its characteristics is considered under specific examples of the existing combined disc coulters. The advantage of this classification table in comparison with the available ones is that its structure and form allow to easily supplement the features characterizing the studied operating unit without changing the algorithm for digital code generation. The proposed classification of combined disc coulters will contribute to a deeper solution of problems of synthesis and analysis of these operating units, will allow to use the digital coding to describe the entire diversity of features thereof.При возделывании сельскохозяйственных культур важнейшее значение имеют предпосевная обработка почвы и посев. Качество выполнения этих операций определяется выбором технологических средств, их техническим состоянием, настройкой и регулировкой, а также соблюдением всех агротехнических требований. В настоящее время зарубежные и отечественные посевные машины все чаще оборудуются дисковыми комбинированными сошниками. Эти агрегаты позволяют комбинировать операции подготовки почвы, внутрипочвенного внесения стартовой дозы фосфорных удобрений и посева сельскохозяйственных культур. В данной статье приведена структурно-морфологическая классификация сошников по 2 основополагающим, 12 конструктивным и 6 технологическим признакам. Показано применение этой классификационной таблицы для описания предназначения и характеристик посевных рабочих органов, а также формирования для них цифровой индикационной записи. На конкретных примерах существующих комбинированных дисковых сошников рассмотрена возможность воспроизведения цифровой информации о посевном рабочем органе в виде многообразия его характеристик. Преимущество данной классификационной таблицы по сравнению с имеющимися заключается в том, что ее структура и форма позволяют легко дополнять признаки, характеризующие изучаемый рабочий орган, не изменяя алгоритм образования цифрового кода. Предлагаемая классификация комбинированных дисковых сошников будет способствовать более глубокому решению задач синтеза и анализа этих рабочих органов, позволит применять цифровое кодирование для описания всего многообразия их признако

Genetics of Host Response to Leishmania tropica in Mice – Different Control of Skin Pathology, Chemokine Reaction, and Invasion into Spleen and Liver

Several hundred million people are exposed to the risk of leishmaniasis, a disease caused by intracellular protozoan parasites of several Leishmania species and transmitted by phlebotomine sand flies. In humans, L. tropica causes cutaneous form of leishmaniasis with painful and long-persisting lesions in the site of the insect bite, but the parasites can also penetrate to internal organs. The relationship between the host genes and development of the disease was demonstrated for numerous infectious diseases. However, the search for susceptibility genes in the human population could be a difficult task. In such cases, animal models may help to discover the role of different genes in interactions between the parasite and the host. Unfortunately, the literature contains only a few publications about the use of animals for L. tropica studies. Here, we report an animal model suitable for genetic, pathological and drug studies in L. tropica infection. We show how the host genotype influences different disease symptoms: skin lesions, parasite dissemination to the lymph nodes, spleen and liver, and increase of levels of chemokines CCL2, CCL3 and CCL5 in serum