2,132 research outputs found

    New evidence of the nonglaciated development of the northern part of the Western Siberian lowland in the Quaternary period

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    To solve the controversially debated problem related to the areal extent of the ice sheet in Western Siberia in the Quaternary period, we have studied the development of cold born objects of this area estimating the relationships between them in terms of cryogenic diversity. We have obtained a field of new cross data related to the development of cryogenic and glacial phenomena, their relationship, and traces they left. The research showed that, in this area, the trend of rock freezing is clearly reflected in the Quaternary formations, but there were no conditions for ice sheet development even during the cryochrons

    Morphological record of pedogenesis and landscape evolution in the upper quaternary pedosediments within the upper Volga river basin

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    The morphological record of pedogenesis (mostly at a micromorphological scale) and the features of paleosols developed at the northern geographical extremity of the MIS3 paleopedoshpere (including the Bryansk fossil soils) are described. The profiles of the MIS3 paleosols (dark humic gley and peaty gley with the14Π‘-age around 29-50 cal kyr BP) are located within the periglacial zone in the centre of the Russian Plain (56.7Β°-58.5Β° N) within the Upper Volga drainage basin. An assemblage of stable micromorphological features of paleosols studied includes the following: 1) ferruginous nodules and other pedofeatures, occasionally fragmented; 2) concentration (separation) of sand grains within certain microzones; 3) inclusions of raw organic matter, often deformed and oriented to different degrees within the matrix. Despite being buried for a long time period and superimposed by the Holocene pedogenetic processes (clay illuviation), the paleosols preserve some features of short-term (101-102 yr) and medium-term (102-103-4 yr) elementary pedogenetic processes (EPP). The short-term EPP include gleying, structure forming and cryogenic processes. The medium-term EPP include humus formation, peat formation and organic matter accumulation. A hypothesis of cryogenic formation of the paleosols studied is substantiated. Only an almost impermeable layer of permafrost could cause water-logging and gleying in these geological and geomorphological conditions

    Low-Mass Star Formation, Triggered by Supernova in Primordial Clouds

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    The evolution of a gas shell, swept by the supernova remnant of a massive first generation star, is studied with H_2 and HD chemistry taken into account. When a first-generation star explodes as a supernova, H_2 and HD molecules are formed in the swept gas shell and effectively cool the gas shell to temperatures of 32 K - 154 K. If the supernova remnant can sweep to gather the ambient gas, the gas shell comes to be dominated by its self-gravity, and hence, is expected to fragment. Our result shows that for a reasonable range of temperatures (200 K - 1000 K) of interstellar gas, the formation of second-generation stars can be triggered by a single supernova or hypernova.Comment: 38pages, 10 figures, The Astrophysical Journal, accepted 8 Dec. 200

    Breeding columnar apple-tree cultivars for supercompact growth habit

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    This work was based on the combinatorial breeding technique using donors of the columnar growth type (Co gene), sources of winter hardiness and high consumer qualities, and scab immunity donors (Rvi6 gene). The selection in the columnar apple-tree hybrid progeny was accompanied by the assessment of growth vigor, compactness degree, and seedling cultivability in accordance with the guidelines.Due to the increasing popularity of apple trees with the columnar crown type, the volume of breeding work for columnar growthΒ  habitΒ  atΒ  theΒ  RussianΒ  ResearchΒ  InstituteΒ  ofΒ  FruitΒ  CropΒ  BreedingΒ  (VNIISPK)Β  overΒ  theΒ  pastΒ  9 yearsΒ  amountedΒ  to 133,582 flowers, or one third of the entire hybridization envisaged by the apple-tree breeding program. Meticulous selection of parent forms is carried out in order to incorporate a set of useful traits in the columnar growth habit genotype. Both cultivars and hybrid forms serve as sources and donors of the traits interesting for breeders. All the studied cultivars released by VNIISPK are dwarf: their height is within the range from 287 cm (cv. β€˜Priokskoe’) to 198 cm (cv. β€˜Orlovskaya Yesenia’), and they can be recommended for both commercial plantations and amateur gardens. The columnar form 34-34-98 is characterized by a unique degree of compactness (the ratio of the internode length to the shoot diameter) equal to 0.4 versus the average value of 1.6 for this indicator in the studied columnar cultivars. This form was involved in the release of 78 promising hybrid seedlings, the best of which (38.5%) were transferred to the garden for primary variety trials. A large yield of seedlings characterized by high compactness in the progeny of the columnar apple tree 34-34-98 makes it possible to recommend it for the development of new apple-tree genotypes for highly cost-effective orchards with high tree planting density

    The Supernova Triggered Formation and Enrichment of Our Solar System

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    We investigate the enrichment of the pre-solar cloud core with short lived radionuclides (SLRs), especially 26Al. The homogeneity and the surprisingly small spread in the ratio 26Al/27Al observed in the overwhelming majority of calcium-aluminium-rich inclusions (CAIs) in a vast variety of primitive chondritic meteorites places strong constraints on the formation of the the solar system. Freshly synthesized radioactive 26Al has to be included and well mixed within 20kyr. After discussing various scenarios including X-winds, AGB stars and Wolf-Rayet stars, we come to the conclusion that triggering the collapse of a cold cloud core by a nearby supernova is the most promising scenario. We then narrow down the vast parameter space by considering the pre-explosion survivability of such a clump as well as the cross-section necessary for sufficient enrichment. We employ numerical simulations to address the mixing of the radioactively enriched SN gas with the pre-existing gas and the forced collapse within 20kyr. We show that a cold clump of 10Msun at a distance of 5pc can be sufficiently enriched in 26Al and triggered into collapse fast enough - within 18kyr after encountering the supernova shock - for a range of different metallicities and progenitor masses, even if the enriched material is assumed to be distributed homogeneously in the entire supernova bubble. In summary, we envision an environment for the birth place of the Solar System 4.567Gyr ago similar to the situation of the pillars in M16 nowadays, where molecular cloud cores adjacent to an HII region will be hit by a supernova explosion in the future. We show that the triggered collapse and formation of the Solar System as well as the required enrichment with radioactive 26Al are possible in this scenario.Comment: 12 pages, 8 figures, accepted for publication in ApJ. Resolution of most figures degraded to fit within arXiv size limits. A full resolution version is available at http://www.usm.uni-muenchen.de/~gritschm/Gritschneder_2011_sun.pd

    Fractional Variations for Dynamical Systems: Hamilton and Lagrange Approaches

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    Fractional generalization of an exterior derivative for calculus of variations is defined. The Hamilton and Lagrange approaches are considered. Fractional Hamilton and Euler-Lagrange equations are derived. Fractional equations of motion are obtained by fractional variation of Lagrangian and Hamiltonian that have only integer derivatives.Comment: 21 pages, LaTe

    Coronal mass ejections as expanding force-free structures

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    We mode Solar coronal mass ejections (CMEs) as expanding force-fee magnetic structures and find the self-similar dynamics of configurations with spatially constant \alpha, where {\bf J} =\alpha {\bf B}, in spherical and cylindrical geometries, expanding spheromaks and expanding Lundquist fields correspondingly. The field structures remain force-free, under the conventional non-relativistic assumption that the dynamical effects of the inductive electric fields can be neglected. While keeping the internal magnetic field structure of the stationary solutions, expansion leads to complicated internal velocities and rotation, induced by inductive electric field. The structures depends only on overall radius R(t) and rate of expansion \dot{R}(t) measured at a given moment, and thus are applicable to arbitrary expansion laws. In case of cylindrical Lundquist fields, the flux conservation requires that both axial and radial expansion proceed with equal rates. In accordance with observations, the model predicts that the maximum magnetic field is reached before the spacecraft reaches the geometric center of a CME.Comment: 19 pages, 9 Figures, accepted by Solar Physic

    ΠŸΠΎΠ΄Π³ΠΎΡ‚ΠΎΠ²ΠΊΠ° ΠΊ анСстСзии Π±ΠΎΠ»ΡŒΠ½Ρ‹Ρ… с ΡΠΎΠΏΡƒΡ‚ΡΡ‚Π²ΡƒΡŽΡ‰Π΅ΠΉ ΠΏΠ°Ρ‚ΠΎΠ»ΠΎΠ³ΠΈΠ΅ΠΉ Π»Π΅Π³ΠΊΠΈΡ… ΠΈ высоким риском развития послСопСрационных Π»Π΅Π³ΠΎΡ‡Π½Ρ‹Ρ… ослоТнСний

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    The objective:Β basing on published data, to highlight the main issues of preparation of patients with concomitant lung pathology and a high risk of developing postoperative pulmonary complications for planned surgical interventions.Results:Β changes made to international guidelines over the past 5 years based on evidence-based studies and meta-analyzes have been analyzed. The article presents data on preoperative management of patients with concomitant lung pathologies and a high risk of postoperative pulmonary complications, assessment of the risk of developing these complications based on evaluation of the functional status of patients. It analyzes the contemporary recommendations on the perioperative prevention of pulmonary complications, the use of physical exercises and respiratory gymnastics in the perioperative period in patients with a high risk of postoperative pulmonary complications. It is concluded that the implementation of comprehensive strategy aimed at reducing the risk of pulmonary complications should ensure decrease in their frequency and mortality due to them.ЦСль:Β Π½Π° основании Π΄Π°Π½Π½Ρ‹Ρ… Π»ΠΈΡ‚Π΅Ρ€Π°Ρ‚ΡƒΡ€Ρ‹ ΠΎΡΠ²Π΅Ρ‚ΠΈΡ‚ΡŒ основныС полоТСния ΠΏΡ€ΠΎΠ±Π»Π΅ΠΌΡ‹ ΠΏΠΎΠ΄Π³ΠΎΡ‚ΠΎΠ²ΠΊΠΈ ΠΏΠ°Ρ†ΠΈΠ΅Π½Ρ‚ΠΎΠ² с ΡΠΎΠΏΡƒΡ‚ΡΡ‚Π²ΡƒΡŽΡ‰Π΅ΠΉ ΠΏΠ°Ρ‚ΠΎΠ»ΠΎΠ³ΠΈΠ΅ΠΉ Π»Π΅Π³ΠΊΠΈΡ… ΠΈ высоким риском развития послСопСрационных Π»Π΅Π³ΠΎΡ‡Π½Ρ‹Ρ… ослоТнСний ΠΊ ΠΏΠ»Π°Π½ΠΎΠ²Ρ‹ΠΌ ΠΎΠΏΠ΅Ρ€Π°Ρ‚ΠΈΠ²Π½Ρ‹ΠΌ Π²ΠΌΠ΅ΡˆΠ°Ρ‚Π΅Π»ΡŒΡΡ‚Π²Π°ΠΌ.Π Π΅Π·ΡƒΠ»ΡŒΡ‚Π°Ρ‚Ρ‹:Β Π²Ρ‹ΠΏΠΎΠ»Π½Π΅Π½ Π°Π½Π°Π»ΠΈΠ· ΠΈΠ·ΠΌΠ΅Π½Π΅Π½ΠΈΠΉ, внСсСнных Π² ΠΌΠ΅ΠΆΠ΄ΡƒΠ½Π°Ρ€ΠΎΠ΄Π½Ρ‹Π΅ клиничСскиС Ρ€Π΅ΠΊΠΎΠΌΠ΅Π½Π΄Π°Ρ†ΠΈΠΈ Π·Π° послСдниС 5 Π»Π΅Ρ‚ Π½Π° основС Π΄ΠΎΠΊΠ°Π·Π°Ρ‚Π΅Π»ΡŒΠ½Ρ‹Ρ… исслСдований ΠΈ ΠΌΠ΅Ρ‚Π°Π°Π½Π°Π»ΠΈΠ·ΠΎΠ². ΠŸΡ€Π΅Π΄ΡΡ‚Π°Π²Π»Π΅Π½Ρ‹ Π΄Π°Π½Π½Ρ‹Π΅ Π² ΠΎΡ‚Π½ΠΎΡˆΠ΅Π½ΠΈΠΈ вСдСния Π² ΠΏΡ€Π΅Π΄ΠΎΠΏΠ΅Ρ€Π°Ρ†ΠΈΠΎΠ½Π½ΠΎΠΌ ΠΏΠ΅Ρ€ΠΈΠΎΠ΄Π΅ Π±ΠΎΠ»ΡŒΠ½Ρ‹Ρ… с ΡΠΎΠΏΡƒΡ‚ΡΡ‚Π²ΡƒΡŽΡ‰Π΅ΠΉ ΠΏΠ°Ρ‚ΠΎΠ»ΠΎΠ³ΠΈΠ΅ΠΉ Π»Π΅Π³ΠΊΠΈΡ… ΠΈ высоким риском послСопСрационных Π»Π΅Π³ΠΎΡ‡Π½Ρ‹Ρ… ослоТнСний, опрСдСлСния риска развития этих ослоТнСний Π½Π° основС ΠΎΡ†Π΅Π½ΠΊΠΈ Ρ„ΡƒΠ½ΠΊΡ†ΠΈΠΎΠ½Π°Π»ΡŒΠ½ΠΎΠ³ΠΎ статуса Π±ΠΎΠ»ΡŒΠ½Ρ‹Ρ…. ΠŸΡ€ΠΎΠ°Π½Π°Π»ΠΈΠ·ΠΈΡ€ΠΎΠ²Π°Π½Ρ‹ соврСмСнныС Ρ€Π΅ΠΊΠΎΠΌΠ΅Π½Π΄Π°Ρ†ΠΈΠΈ ΠΏΠΎ ΠΏΠ΅Ρ€ΠΈΠΎΠΏΠ΅Ρ€Π°Ρ†ΠΈΠΎΠ½Π½ΠΎΠΉ ΠΏΡ€ΠΎΡ„ΠΈΠ»Π°ΠΊΡ‚ΠΈΠΊΠ΅ Π»Π΅Π³ΠΎΡ‡Π½Ρ‹Ρ… ослоТнСний, ΠΏΡ€ΠΈΠΌΠ΅Π½Π΅Π½ΠΈΡŽ физичСских ΡƒΠΏΡ€Π°ΠΆΠ½Π΅Π½ΠΈΠΉ ΠΈ Π΄Ρ‹Ρ…Π°Ρ‚Π΅Π»ΡŒΠ½ΠΎΠΉ гимнастики Π² ΠΏΠ΅Ρ€ΠΈΠΎΠΏΠ΅Ρ€Π°Ρ†ΠΈΠΎΠ½Π½ΠΎΠΌ ΠΏΠ΅Ρ€ΠΈΠΎΠ΄Π΅ Ρƒ Π±ΠΎΠ»ΡŒΠ½Ρ‹Ρ… с высоким риском послСопСрационных Π»Π΅Π³ΠΎΡ‡Π½Ρ‹Ρ… ослоТнСний. Π‘Π΄Π΅Π»Π°Π½ Π²Ρ‹Π²ΠΎΠ΄, Ρ‡Ρ‚ΠΎ практичСская рСализация комплСксной стратСгии, Π½Π°ΠΏΡ€Π°Π²Π»Π΅Π½Π½ΠΎΠΉ Π½Π° сниТСниС риска Π»Π΅Π³ΠΎΡ‡Π½Ρ‹Ρ… ослоТнСний, Π΄ΠΎΠ»ΠΆΠ½Π° ΠΎΠ±Π΅ΡΠΏΠ΅Ρ‡ΠΈΡ‚ΡŒ сниТСниС ΠΈΡ… частоты ΠΈ ΠΎΠ±ΡƒΡΠ»ΠΎΠ²Π»Π΅Π½Π½ΡƒΡŽ ΠΈΠΌΠΈ Π»Π΅Ρ‚Π°Π»ΡŒΠ½ΠΎΡΡ‚ΡŒ

    Use of different types of active carbons in adsorption process of precious metals

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    In the article the different types of activated carbons for using in adsorption process of precious metals from solution leaching is considered. Brand industrial sorbents possessing better sorption properties are considered. One of the types of carbon sorbents is revealed by the example of one way of increasing the sorption capacity of the manufacturing process.Π’ Ρ€Π°Π±ΠΎΡ‚Π΅ рассмотрСны Ρ€Π°Π·Π½Ρ‹Π΅ Π²ΠΈΠ΄Ρ‹ Π°ΠΊΡ‚ΠΈΠ²ΠΈΡ€ΠΎΠ²Π°Π½Π½Ρ‹Ρ… ΡƒΠ³Π»Π΅ΠΉ для использования Π² процСссС адсорбции Π΄Ρ€Π°Π³ΠΎΡ†Π΅Π½Π½Ρ‹Ρ… ΠΌΠ΅Ρ‚Π°Π»Π»ΠΎΠ² ΠΈΠ· растворов выщСлачивания. ΠŸΠΎΠΊΠ°Π·Π°Π½Ρ‹ ΠΌΠ°Ρ€ΠΊΠΈ ΠΏΡ€ΠΎΠΌΡ‹ΡˆΠ»Π΅Π½Π½Ρ‹Ρ… сорбСнтов, ΠΎΠ±Π»Π°Π΄Π°ΡŽΡ‰ΠΈΠ΅ Π½Π°ΠΈΠ»ΡƒΡ‡ΡˆΠΈΠΌΠΈ сорбционными свойствами. ВыявлСн ΠΎΠ΄ΠΈΠ½ ΠΈΠ· ΠΏΡƒΡ‚Π΅ΠΉ ΠΏΠΎΠ²Ρ‹ΡˆΠ΅Π½ΠΈΡ сорбционной способности Π² процСссС производства Π½Π° ΠΏΡ€ΠΈΠΌΠ΅Ρ€Π΅ ΠΎΠ΄Π½ΠΎΠ³ΠΎ ΠΈΠ· Π²ΠΈΠ΄ΠΎΠ² ΡƒΠ³Π»Π΅Ρ€ΠΎΠ΄Π½Ρ‹Ρ… сорбСнтов
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