649 research outputs found

    Speeding Strings

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    There is a class of single trace operators in N=4{\cal N}=4 Yang-Mills theory which are related by the AdS/CFT correspondence to classical string solutions. Interesting examples of such solutions corresponding to periodic trajectories of the Neumann system were studied recently. In our paper we study a generalization of these solutions. We consider strings moving with large velocities. We show that the worldsheet of the fast moving string can be considered as a perturbation of the degenerate worldsheet, with the small parameter being the relativistic factor 1v2\sqrt{1-v^2}. The series expansion in this relativistic factor should correspond to the perturbative expansion in the dual Yang-Mills theory. The operators minimizing the anomalous dimension in the sector with given charges correspond to periodic trajectories in the mechanical system which is closely related to the product of two Neumann systems.Comment: v3: added a reference to the earlier wor

    Study of the dynamic structure of the near-lunar orbital space

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    The knowledge of the dynamic features of the near-lunar space is necessary for its optimal mastering. This work is devoted to a study of the special features of the dynamics of the artificial Moon satellites (AMS) with intermediate and high orbits in the range of semimajor axes from 2500 to 26000 km

    ASSESSMENT OF REFRACTORY GOLD-BEARING ORES BASED OF INTERPRETATION OF THERMAL ANALYSIS DATA

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    The article presents the results of a study on the possibility to assess refractory gold-bearing ores using thermal analysis data. It studies the flotation concentrates obtained during the enrichment of double refractory sulfide gold-bearing ores. This type of ore is complicated by the fine impregnation of gold in sulphide minerals and the presence of sorption-active scattered carbonaceous matter, which is in close association with sulphides. The results of thermogravimetric and mass spectrometric studies of refractory gold-bearing ores are presented. The obtained fragments for kerogen CH (m/z = 15), C2H (m/z = 29) and C3H (m/z = 43) indicate the presence of various types of carbonaceous matter in the studied samples. It is justified that the degree of sorption activity of carbonaceous matter depends on the presence of kerogen and bitumen in the ore. High sorption activity of scattered carbonaceous material significantly affects the processing technology of ores and concentrates, both flotation and pyro- and hydrometallurgical methods. Thermogravimetric and mass spectroscopic analyzes can be used to determine the degree of preg-robbing of refractory gold-bearing ores. The obtained results predetermine the direction of creating new methods and technologies in the field of decarburization of refractory gold-bearing ores in the integrated development of solid minerals in the mining regions of Russia

    Monitoring technology: The qualimetric foundations of the educational process of the university

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    © 2016 Krokhina et al.The relevance of the research problem is determined by the current discrepancy between the requirements of society to quality of students’ training– future specialists with higher education, on the one hand, and level of training received by graduates on the other hand. The tendency of the discrepancies noted is a consequence of the properties of the inertia of the educational process that gives it stability, but also hindering rapid response to the recent changes in the sphere of science, production, culture, industry and other spheres of life. The current controversy requires scientific correction and rethinking of the methodology of quality evaluation of the educational process. In this regard, priority attention in this article is devoted to justification of qualimetric grounds for the projecting and implementation of monitoring technologies in the educational process of the University. A leading research method is a simulation method allowing justification of monitoring technologies as qualimetric bases of educational process of the University and rethinking their valuable content in the students’ training. The article presents the discourse of the concept "monitoring technology"; it reveals the essence, structure and content of qualimetric grounds of the monitoring technologies in the educational process of the University; on the basis of the study’s results conducted the elective interdisciplinary course "Qualimetric grounds of monitoring technologies" is justified. Productivity of its implementation is proven using the criteria: formation of knowledge of the content of studied course, of the experience in using the acquired knowledge in standard and non-standard situations in the educational process; the integrity of knowledge about the qualimetric basis of the monitoring technologies in the students’ training; the students' readiness to be engaged professionally in any activity; formation of competences of the culture of mental labor in accordance with the personal position of the student in self-organization and self-transformation; the personal creativity of the student – future specialist, relevant to qualimetric objectives of the monitoring technology. The paper can be useful to teachers, methodologists, managers of the universities

    Folded Three-Spin String Solutions in AdS_5 x S^5

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    We construct a spinning closed string solution in AdS_5 x S^5 which is folded in the radial direction and has two equal spins in AdS_5 and a spin in S^5. The energy expression of the three-spin solution specified by the folding and winding numbers for the small S^5 spin shows a logarithmic behavior and a one-third power behavior of the large total AdS_5 spin, in the long string and in the short string located near the boundary of AdS_5 respectively. It exhibits the non-regular expansion in the 't Hooft coupling constant, while it takes the regular one when the S^5 spin becomes large.Comment: 14 pages, LaTeX, no figures, a reference adde

    Multi-spin strings on AdS(5)xT(1,1) and operators of N=1 superconformal theory

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    We study rotating strings with multiple spins in the background of AdS5×T1,1AdS_5\times T^{1,1}, which is dual to a N=1\mathcal{N}=1 superconformal field theory with global symmetry SU(2)×SU(2)×U(1)SU(2)\times SU(2)\times U(1) via the AdS/CFT correspondence. We analyse the limiting behaviour of macroscopic strings and discuss the identification of the dual operators and how their anomalous dimensions should behave as the global charges vary. A class of string solutions we find are dual to operators in SU(2) subsector, and our result implies that the one-loop planar dilatation operator restricted to the SU(2) subsector should be equivalent to the hamiltonian of the integrable Heisenberg spin chain.Comment: 8 pages, revtex4, twocolum

    ROCK FAILURE INFLUENCE OF THE BLOCK-HIERARCHICAL STRUCTURE OF ROCKS ON THE PECULIARITIES OF SEISMIC WAVE PROPAGATION

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    The analysis is performed for the parameters of long pendulum-type waves in a one-dimensional periodic system with an arbitrary hierarchical structure. A case study is carried out into the wave propagation peculiarities in an impact-excited system of equal rigid blocks with parting layers differing in rigidity. The pendulum wave velocity in the automodel block-hierarchical system is determined

    Spinning Pulsating String Solitons in AdS_5 x S^5

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    We point out the existence of some simple string solitons in AdS_5 x S^5, which at the same time are spinning in AdS_5 and pulsating in S^5, or vice-versa. This introduces an additional arbitrary constant into the scaling relations between energy and spin or R-charge. The arbitrary constant is not an angular momentum, but can be related to the amplitude of the pulsation. We discuss the solutions in detail and consider the scaling relations. Pulsating multi spin or multi R-charge solutions can also be constructed.Comment: 15 pages, Late

    SPECIES DIVERSITY OF THE VIR COLLECTION OF GRAIN LEGUME GENETIC RESOURCES AND ITS USE IN DOMESTIC BREEDING

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    The world’s genebanks hold 7.5 million germplasm accessions of plant genetic resources (PGR). One of the qualitative characteristics of the PGR collections is the species diversity, in particular, the presence of crop wild relatives (CWR), which makes it possible to widen the use of gene pools in the breeding process. The collection of the Vavilov Institute (VIR) is one of the most diverse holdings in the number of plant species. A survey is provided here of the species diversity in VIR’s grain legume collection, and its use in domestic breeding practice is analyzed. Comparison of this diversity with the state of PGR exploitation in the world makes it possible to assess the prospects of more efficient utilization of gene pool potential, especially for species that are unjustifiably cultivated on a too small scale or even neglected as crops in this country. The VIR collection of grain legumes incorporates 196 species from 9 genera of the family Fabaceae. This number includes cultigens and CWR. The cultivars of 21 species of grain legumes listed in the State Register of Breeding Achievements (2018) are adapted to the soil and climate conditions of this country. However, the species diversity of the collection could be used more efficiently in domestic plant breeding and crop production. This concerns both underutilized crops in Russia (broad beans, lima beans and grass pea) and those whose adaptive potential is adjusted only to certain and limited areas of the Russian Federation (Tepary beans and Vigna spp.). It is also necessary to exploit more efficiently species of the wild flora, both for direct utilization as pastures, green manure or phytoremediation crops and for introgressive breeding and domestication (Vicia benghalensis L., V. narbonensis L., Lathyrus sylvestris L., Lupinus hartwegii Lindl., etc.). Incorporation of crop wild relatives into the breeding process is promising for crop improvement in a number of aspects: for example, to increase resistance to diseases, pests, abiotic stressors, etc
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