170 research outputs found

    Emergent Calabi-Yau Geometry

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    We show how the smooth geometry of Calabi-Yau manifolds emerges from the thermodynamic limit of the statistical mechanical model of crystal melting defined in our previous paper arXiv:0811.2801. In particular, the thermodynamic partition function of molten crystals is shown to be equal to the classical limit of the partition function of the topological string theory by relating the Ronkin function of the characteristic polynomial of the crystal melting model to the holomorphic 3-form on the corresponding Calabi-Yau manifold.Comment: 4 pages; v2: revised discussion on wall crossing; v3: typos corrected, published versio

    The tax burden in Russia

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    Main directions of fiscal policy allow economic agents to identify their business objectives, given the proposed changes in the tax area. This increases the certainty of the terms of reference of the economic activities on the territory of the Russian Federation

    New data on geochemical features, fluid mode, age and potential ore content of granitoids of Isherim anticlinorium (North Ural)

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    Granitoids of Ishirim anticlinorium which is one of the major Precambrian structures of the North Urals, are poorly studied by modern geochemical and isotope-geochronological methods that led to the existence of different points of view on formation conditions and age of these rocks. The authors performed a study of the composition of rocks from three massifs - Vels, Moiva and Pos’mak, by chemical analysis and ICP-MS; age determination on zircons by the methods of LA-ICP-MS and SHRIMP, as well as the study of the composition of rock-forming and accessory minerals using microprobe SX-100, which allowed us to obtain fundamentally new data about the age, fluid regime of formation and potential ore content of granitoids. It is shown that the granitoids were probably formed in environments of active continental margin and orogen; the first has the Ediacaran (567.2-558 Ma), the second - Cambrian (530.3-511.1 Ma) age. Discrete intervals of the formation and a fairly significant geochemical differences of Precambrian and Paleozoic granites, allow to attribute them to different complexes - the Ediacaran Moiva complex and Cambrian Vels complex. The complexes are different in composition of fluids which change over time from substantially chlorine to fluorine. With more ancient (Ediacaran) granitoids of Moiva massif can be associated gold-bearing Mo-W mineralization, and with Cambrian granites - rare-metal mineralization (W, Nb, Ta, REE)

    Sc, Cr, Co, Ni, Th and rare earth elements systematics in black shales of Murav’inskaya and Velsovskaya formations (Lyapin-Kutim anticlinorium, the Northern Urals): to the provenance reconstructions

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    The features of the Sc, Cr, Co, Ni, Th and rare earth elements distribution in the black shales of the Riphean Murav’inskaya and Velsovskaya formations in southern part of the Lyapin-Kutim anticlinorium (Northern Ural) are analyzed. The contents of the listed elements in 20 samples of black shales are determined by the ICP-MS method at the IGG UB RAS (Ekaterinburg). Samples of the shales of the Murav’insky formation are selected from the outcrops along the river Vels, below the mouth of Pos’mak River, as well as along Pravaya Rassokha River. The selection was made from outcrops more or less evenly distributed over the studied area. The shales of the Velsovskaya formation were studied from the drilling holes in the basin of Sur’ya Vagranskaya River, as well as in outcrops along the Sibiryakovskaya Martayka and Pravaya Rassokha rivers. In the Sc-Th/Sc diagram, the data points of the black shales of the Murav’inskaya and Velsovskaya formations are fairly compact located between the points of the average composition of the Archean and Proterozoic granites, on the one hand, and tonalite-trondhjemite-granite (TTG) associations of the same age. Approximately the same distribution of the data points of the black shales of these formations can be seen in the La/Sc-Th/Co and La/Sm-Sc/Th diagrams. The average value of ΣРЗЭ in black shales of the Murav’inskaya formation is 316 ± 90 ppm, in the shales of the Velsovskaya Formation it is noticeably lower - 200 ± 47 ppm. The black shales of the Murav’inskaya Formation are substantially enriched with light lanthanides (La/Yb)Nmean = 40, and noticeably depleted by heavy lanthanides, (Gd/Yb)Nmean = 5.4. For the black shales of the Velsovsky formation (La/Yb)Nmean = 22, (Gd/Yb)Nmean = 3.1. This ones and a number of the other data make it possible to conclude that the complexes of rock-sources of fine aluminosiliciclastics for black shales of Murav’inskaya and Velsovskaya formations had a rather specific composition. On the basis of a comparison of the geochemical features of the black shales of the southern part of the Lyapin-Kutim anticlinorium and potential sources of fine aluminosiliciclastics, the conclusion is based that such rock complexes could be, from one side, the Archean and/or Proterozoic TTG associations and granites of the same age of the Eastern European platform, and, from another side, certain local rocks with high Cr contents and significant differentiation of REE, similar in composition to the products of kimberlite magmatism

    B2 sequences whose terms are squares

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    6 páginas.Peer reviewe

    Повышение эффективности статистического подхода к обработке данных контроля технологического процесса транспорта нефти

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    Тема научной работы выбрана согласно стратегии совместного сотрудничества РФ и КНР, в которой возрастают требования к эффективности использования нефтетранспортных предприятий. Целью данной дипломной работы является изучение котроля техгологического процесса во времени на примере транспорта жидкости, при помощи метода контрольных карт Шухарта, метод главных компонент и стандарт статистика. В данной работе был произведен расчет и рассмотрена возможность осуществления технологического контроля при мониторинге многопараметрового процесса транспорта жидкости по трубопроводу.The theme of the scientific work is selected according to the strategy of joint cooperation between the Russian Federation and the PRC, in which the requirements to the effectiveness of the use of oil transportation enterprises are increasing. The purpose of this thesis is to study the control of the technological process in time using the example of fluid transport, using the method of Shewhart control charts, the method of main components and the standard statistic. In this paper, a calculation was made and the possibility of implementing technological control in monitoring a multi-parameter fluid transport process through a pipeline was considered

    Bochner transforms, perturbations and amoebae of holomorphic almost periodic mappings in tube domains

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    We give an alternative representation of the closure of the Bochner transform of a holomorphic almost periodic mapping in a tube domain. For such mappings we introduce a new notion of amoeba and we show that, for mappings which are regular in the sense of Ronkin, this new notion agrees with Favorov's one. We prove that the amoeba complement of a regular holomorphic almost periodic mapping, defined on Cn and taking its values in Cm+1, is a Henriques m-convex subset of Rn. Finally, we compare some different notions of regularity
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