306 research outputs found

    New type of stable particle like states in chiral magnets (Chiral bobbers)

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    We present a new type of a thermodynamically stable magnetic state at interfaces and surfaces of chiral magnets. The state is a soliton solution of micromagnetic equations localized in all three dimensions near a boundary and contains a singularity, but nevertheless has a finite energy. Both features combine to a quasi-particle state for which we expect unusual transport and dynamical properties. It exhibits high thermal stability and thereby can be considered as promising object for fundamental research and practical applications in spintronic devices. We provide arguments that such a state can be found in different B20-type alloys e.g. Mn1x_{1-x}Fex_xGe, Mn1x_{1-x}Fex_xSi, Fe1x_{1-x}Cox_xSi.Comment: accepted in PR

    Multiple Conclusion Rules in Logics with the Disjunction Property

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    We prove that for the intermediate logics with the disjunction property any basis of admissible rules can be reduced to a basis of admissible m-rules (multiple-conclusion rules), and every basis of admissible m-rules can be reduced to a basis of admissible rules. These results can be generalized to a broad class of logics including positive logic and its extensions, Johansson logic, normal extensions of S4, n-transitive logics and intuitionistic modal logics

    SU(2) Skyrme Vortices

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    A regular method for constructing vortex-like solutions with cylindrical symmetry to the equations of the SU(2) Skyrme chiral model is proposed. A numerical estimate for the length density of mass is given

    Interaction of Individual Skyrmions in Nanostructured Cubic Chiral Magnet

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    We report the direct evidence of field-dependent character of the interaction between individual magnetic skyrmions as well as between skyrmions and edges in B20-type FeGe nanostripes observed by means of high resolution Lorentz transmission electron microscopy. It is shown that above certain critical values of external magnetic field the character of such long-range skyrmion interactions change from attraction to repulsion. Experimentally measured equilibrium inter-skyrmion and skrymion-edge distances as function of applied magnetic field shows quantitative agreement with the results of micromagnetic simulations. Important role of demagnetizing fields and internal symmetry of three-dimensional magnetic skyrmions are discussed in details.Comment: accepted in PR

    Exact Self-consistent Particle-like Solutions to the Equations of Nonlinear Scalar Electrodynamics in General Relativity

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    Exact self-consistent particle-like solutions with spherical and/or cylindrical symmetry to the equations governing the interacting system of scalar, electromagnetic and gravitational fields have been obtained. As a particular case it is shown that the equations of motion admit a special kind of solutions with sharp boundary known as droplets. For these solutions, the physical fields vanish and the space-time is flat outside of the critical sphere or cylinder. Therefore, the mass and the electric charge of these configurations are zero.Comment: 17 pages, Submitted to the International Journal of Theoretical Physic

    Latex agglutination test for rapid detection of antibodies to infectious hematopoietic necrosis virus of salmon

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    Latex-agglutination preparations were produced for detection of antibodies to infectious hematopoietic necrosis virus of salmon with analytical sensitivity of 0,9 цд/ті. While testing 40 blood samples using latex-agglutination test the diagnostic sensitivity and specificity were 92 and 100%, respectively. The latex-agglutination is a simple and rapid test; it can be used for retrospective diagnostics of the disease and determination of the titer of antibodies to the virus under conditions of a veterinary laboratory and even a fish farm

    VECTORIZATION OF SMALL-SIZED SPECIAL-TYPE MATRICES MULTIPLICATION USING INSTRUCTIONS AVX-512

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    Modern software packages for supercomputer calculations require a large amount of computing resources. At the same time there are new hardware architectures that open up new opportunities for program code optimizing. The AVX-512 instruction set is a unique tool with many useful features that allow creating high-performance parallel code for supercomputer calculations. The most striking features of AVX-512 instruction set are special mask registers that allow selecting the elements of vectors for processing, combined arithmetic instructions, vector transcendental instructions, operations of multiple memory access with different arbitrary offsets, and many others. Some numerical methods use special objects, the processing speed of which critically affects the speed of the entire calculation package. Matrices of size 5 by 5, represented as submatrices of 8-by-8 matrices, are such critical objects for the numerical RANS/ILES method, which is used for nonstationary turbulent flows calculating. The main operation for working with such matrices is multiplication. In this paper we consider an effective approach to vectorizing the multiplication of 8-by-8 matrices. Further, the effect of decreasing the dimension of the matrices on the efficiency of vectorization is estimated. The considered approach is realized with the help of special intrinsic functions for the AVX-512 instruction set and it is checked on a supercomputer located in JSCC RAS

    Finitely generated free Heyting algebras via Birkhoff duality and coalgebra

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    Algebras axiomatized entirely by rank 1 axioms are algebras for a functor and thus the free algebras can be obtained by a direct limit process. Dually, the final coalgebras can be obtained by an inverse limit process. In order to explore the limits of this method we look at Heyting algebras which have mixed rank 0-1 axiomatizations. We will see that Heyting algebras are special in that they are almost rank 1 axiomatized and can be handled by a slight variant of the rank 1 coalgebraic methods

    Resistance to causal agents of late blight and golden potato nematode of the modern cultivars of seed potatoes and their phytosanitary status in various agroclimatic zones of the European part of Russia

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    The active expansion of foreign potato cultivars on the territory of the Russian Federation has led to a change in the dominant pathogen species and to the emergence of new pathotypes of causal agents of harmful potato diseases. The aim of the study was to evaluate resistance to Phytophthora infestans and Globodera rostochiensis of modern potato cultivars and determine the distribution of fungal and oomycetic diseases on potato cultivars in various agroclimatic zones of Russia. The resistance of 41 foreign cultivars was evaluated to pathotype Ro1 G. rostochiensis and to isolate VZR17 P. infestans with virulence genes 1.2.3.4.5.6.7.8.9.10.11. Resistant to G. rostochiensis were 38 cultivars. 57R marker of the H1 gene conferring resistance to the Ro1 pathotype of G. rostochiensis was detected in 96.6 % of the nematode resistant cultivars studied; susceptible varieties did not possess this marker. Absolute resistance to the causative agent of late blight was demonstrated by the cultivars Alouette and Sarpo Mira (score 9); high levels of resistance (score 6 and 7) were determined for the cultivars Evolution, Red Fantasy and Ricarda. The cultivars Baltic Rose, Damaris, Desiree, Gala, Labella, Laperla, Mia, Sanibel, Zekura, Queen Anne, Red Lady and ‘7 for 7’ were classified as susceptible, although the characteristics of originators indicated average resistance to late blight. A phytopathological test was conducted on 92 samples of 39 varieties of seed potatoes from four federal districts of the Russian Federation: Volga, NorthWest, Central and North Caucasus. Rhizoctonia solani, Fusarium spp. and Helminthosporium solani are most common on all varieties. 100 % defeat of tubers by H. solani was recorded in various regions on the cultivars Red Scarlett, Evolution, Labella, Colombo, Gala and Nevsky. Widespread Colletotrichum coccodes on tubers of the elite and 2nd reproductions of the potato cultivar Red Scarlett (50.0–71.4 %) was recorded in the Central District

    Pecularities of training of qualified specialists in condition of establishment of ural engineering school

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    В статье рассматриваются вопросы подготовки кадров для наукоемких отраслей промышленности, в частности металлургии. Обозначена специфика начального, среднего и высшего профессионального образования. Авторами представлен алгоритм создания и апробации учебно-методических материалов, используемых для подготовки специалистов со средним профессиональным образованием, готовых по окончанию колледжа работать в компаниях со сложным наукоемким оборудованием.Personnel training for knowledge-intensive industries, in particular metallurgy, is analyzed in the article. The article includes general characteristics of the personnel training with primary, secondary and higher professional education. The authors show the algorithm of creation and testing of educational-methodological documentation for training of specialists with secondary professional education and training procedure of specialists who are ready to work for companies with complex manufacturing equipment immediately after graduating from college
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