1,399 research outputs found

    Guideline on therapeutic dentistry for the 5-th term

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    РУКОВОДСТВАСТОМАТОЛОГИЯ ЛЕЧЕБНО-ВОССТАНОВИТЕЛЬНАЯСТОМАТОЛОГИЯ ТЕРАПЕВТИЧЕСКАЯИНОСТРАННЫЕ СТУДЕНТЫУЧЕБНО-МЕТОДИЧЕСКИЕ ПОСОБИЯПособие составлено в соответствии с учебной программой для медицинских вузов по терапевтической стоматологии. Предназначено для внутреннего использования

    Hybridization and spin-orbit coupling effects in quasi-one-dimensional spin-1/2 magnet Ba3Cu3Sc4O12

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    We study electronic and magnetic properties of the quasi-one-dimensional spin-1/2 magnet Ba3Cu3Sc4O12 with a distinct orthogonal connectivity of CuO4 plaquettes. An effective low-energy model taking into account spin-orbit coupling was constructed by means of first-principles calculations. On this basis a complete microscopic magnetic model of Ba3Cu3Sc4O12, including symmetric and antisymmetric anisotropic exchange interactions, is derived. The anisotropic exchanges are obtained from a distinct first-principles numerical scheme combining, on one hand, the local density approximation taking into account spin-orbit coupling, and, on the other hand, projection procedure along with the microscopic theory by Toru Moriya. The resulting tensors of the symmetric anisotropy favor collinear magnetic order along the structural chains with the leading ferromagnetic coupling J1 = -9.88 meV. The interchain interactions J8 = 0.21 meV and J5 = 0.093 meV are antiferromagnetic. Quantum Monte Carlo simulations demonstrated that the proposed model reproduces the experimental Neel temperature, magnetization and magnetic susceptibility data. The modeling of neutron diffraction data reveals an important role of the covalent Cu-O bonding in Ba3Cu3Sc4O12.Comment: 11 pages, 12 figure

    Phase equilibria and thermodynamic properties of oxide systems on the basis of rare earth, alkaline earth and 3d-transition (Mn, Fe, Co) metals. A short overview of

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    Review is dedicated studies of phase equilibria in the systems based on rare earth elements and 3d transition metals. It’s highlighted several structural families of these compounds and is shown that many were found interesting properties for practical application, such as high conductivity up to the superconducting state, magnetic properties, catalytic activity of the processes of afterburning of exhaust gases, the high mobility in the oxygen sublattice and more

    Highly mobile carriers in orthorhombic phases of iron-based superconductors FeSe1x{}_{1-x}Sx{}_{x}

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    The field and temperature dependencies of the longitudinal and Hall resistivity have been measured for FeSe1x{}_{1-x}Sx{}_{x} (x=0.04, 0.09 and 0.19) single crystals. The sample FeSe0.81{}_{0.81}S0.19{}_{0.19} does not show a transition to an orthorhombic phase and exhibits at low temperatures the transport properties quite different from those of orthorhombic samples. The behavior of FeSe0.81{}_{0.81}S0.19{}_{0.19} is well described by the simple two band model with comparable values of hole and electron mobility. In particular, at low temperatures the transverse resistance shows a linear field dependence, the magnetoresistance follow a quadratic field dependence and obeys to Kohler's rule. In contrast, Kohler's rule is strongly violated for samples having an orthorhombic low temperature structure. However, the transport properties of the orthorhombic samples can be satisfactory described by the three band model with the pair of almost equivalent to the tetragonal sample hole and electron bands, supplemented with the highly mobile electron band which has two order smaller carrier number. Therefore, the peculiarity of the low temperature transport properties of the orthorhombic Fe(SeS) samples, as probably of many other orthorhombic iron superconductors, is due to the presence of a small number of highly mobile carriers which originate from the local regions of the Fermi surface, presumably, nearby the Van Hove singularity points

    Magnetotransport properties of FeSe in fields up to 50T

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    Magnetotransport properties of the high-quality FeSe crystal, measured in a wide temperature range and in magnetic fields up to 50 T, show the symmetry of the main holelike and electronlike bands in this compound. In addition to the main two bands, there is also a tiny, highly mobile, electronlike band which is responsible for the non-linear behavior of ρxy\rho_{xy}(B) at low temperatures and some other peculiarities of FeSe. We observe the inversion of the ρxx\rho_{xx} temperature coeficient at a magnetic field higher than about 20 T which is an implicit conformation of the electron-hole symmetry in the main bands.Comment: MISM 201

    Features of the crystal structure and electrical properties of sodium chloride at pressure 20-50 GPa

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    The electrical properties of polycrystalline samples of sodium chloride are studied at direct and alternating current in a wide range of frequencies at high pressure and room temperature. Graphic analysis of the experimental data [1-3] in the view of equivalent circuits allowed us to separate the contributions to conductivity caused by grains and intergrain boundaries. Features of impedance at pressure up to 37 GPa are in good agreement with earlier data and structural changes. It is shown that in the studied materials the electrical resistance of grains is much greater than the resistance of intergrain boundaries. © 2013 Allerton Press, Inc

    THE PECULARITIES OF CREATION AND IMPLEMENTATION OF NATIONAL INDUSTRIAL POLICIES IN FOREIGN COUNTRIES IN THE TIMES OF INNOVATIONAL ECONOMICS

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    Thе article reviews various peculiarities of formation and implementation of industrial policy in foreign countries that maintain different types of industrial policy. Moreover, it contains the analysis of the foreign experience. It also highlights the prospects for the implementation of foreign experience in Russian Federation, as well as its pros and cons
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