Preparation and characterization of Bi26–2xMn2xMo10O69-d and Bi26.4Mn0.6Mo10–2yMe2yO69-d(Me = V, Fe) solid solutions

Received: 06.06.2017; accepted: 23.06.2017; published: 14.07.2017.Single phase samples of bismuth molybdate, Bi26Mo10O69, doped with Mn on the bismuth sublattice and V, Fe on the molybdenum sublattice were found to crystallize in the triclinic Bi26Mo10O69 structure at low doping levels and in the monoclinic Bi26Mo10O69 structure - at higher dopant concentration. The assumption that all Mn ions have an oxidation state of +2 was confirmed by means of magnetic measurement results analysis using Curie-Weiss law. Conductivity was investigated using impedance spectroscopy. The conductivity of Bi26.4Mn0.6Mo9.6Fe0.4O69-d was 1.2*10-2 S*cm-1 at 973 K and 2.2*10-4 S*cm-1 at 623 K, and the conductivity of Bi26.4Mn0.6Mo9.2V0.8O69-d was 2.2*10-3 S*cm-1 at 973 K and 2.2*10-5 S*cm-1 at 623 K

Crystal structure and conductivity of bismuth-containing complex oxides

In the paper, a comprehensive systematic study of different classes of bismuth containing oxide compounds was carried out. The relationship between composition, temperature and concentration regions of existence of stable, specific structure and properties of solid solutions on the basis of vanadates, molybdates, niobates and bismuth was found. The general regularities of synthesis of solid solutions with different variants of solid-phase and soluble methods were determined. On this basis, the optimal conditions for obtaining single-phase materials were formulated. For the first time the temperature and concentration boundaries of the regions of homogeneity and areas of stable existence of polymorphic modifications of solid solutions were defined and/or refined. The structural parameters of the synthesized phases were determined. By the method of electrochemical impedance spectroscopy the nature and features of impedance spectra, the temperature and concentration dependences of electrical conductivity of ceramic materials based on bismuth containing complex oxides were identified

General Relativistic Effect of Gravitomagnetic Charge on Pulsar Magnetosphere and Particle Acceleration in a Polar Cap

We study magnetospheric structure surrounding rotating magnetized neutron star with nonvanishing NUT (Newman-Tamburino-Unti) parameter. For the simplicity of calculations Goldreich-Julian charge density is analyzed for the aligned neutron star with zero inclination between magnetic field, gravitomagnetic field and rotation axis. From the system of Maxwell equations in spacetime of slowly rotating NUT star, second-order differential equation for electrostatic potential is derived. Analytical solution of this equation indicates the general relativistic modification of an accelerating electric field and charge density along the open field lines by the gravitomagnetic charge. The implication of this effect to the magnetospheric energy loss problem is underlined. In the second part of the paper we derive the equations of motion of test particles in magnetosphere of slowly rotating NUT star. Then we analyze particle motion in the polar cap and show that NUT parameter can significantly change conditions for particle acceleration.Comment: 21 pages, 6 figures, accepted for publication in Ap

The optimization of the system of taxpayers’ state registration using road mapping method

In the state registration of taxpayers is the basis for creation of Unified State Register of Taxpayers (as to legal entities and individual entrepreneurs), which allows controlling completeness and timeliness of taxes’ payment and, consequently, providing formation of budget. The paper analyses legal framework for regulation of taxpayers’ registration, distinguishes the particularities of registration of organizations and private persons (individual entrepreneurs). There is also an analysis of applicable practice of taxpayers’ registration in Russia and the Republic of Mordovia. The positive trends (formation of unified federal registration base for taxpayers’ recording; openness and general availability of information about all taxpayers registered on the territory of Russia; wide list of services on state registration that are rendered by tax authorities to taxpayers; transition to the regime of “single window” in interaction between registering structures; prejudicial regulation of appeal of decisions on state registration of legal entities and individual entrepreneurs) and system problems (impossibility of use of unified registration number of a taxpayer for coordination of information about him in different state organizations; irrelevance and incompleteness of information contained in databases of different state institutions; conscious evasion of taxpayers of performance of tax obligations on registration; difficulty of timely detection of short-lived companies; significant volume of migrant organizations; insufficient technical and program support of regional tax inspections) linked to registration processes are elicited.peer-reviewe

NMR and LDA evidence for spiral magnetic order in the chain cuprate LiCu2O2

We report on {6,7}Li nuclear magnetic resonance measurements of the spin-chain compound LiCu2O2 in the paramagnetic and magnetically ordered states. Below T about 24 K the NMR lineshape presents a clear signature of incommensurate (IC) static modulation of the local magnetic field consistent with an IC spiral modulation of the magnetic moments. {7}Li NMR reveals strong phason-like dynamical fluctuations extending well below 24 K. We hypothesize that a series of phase transitions at 24.2, 22.5, and 9 K reflects a "Devil's staircase" type behavior generic for IC systems. LDA based calculations of exchange integrals reveal a large in-chain frustration leading to a magnetical spiral.Comment: 4 pages, 4 figure

The Indicative Potential of the Forest-Tundra Landscape Component

In order to expand the possibilities of soil-cover remote monitoring and improve prognostic models of active-layer depth dynamics in connection with global climatic changes, the verification of correspondence between plant and soil components of subarctic landscapes is necessary. This is most relevant for the forest-tundra zone,where the variety and mosaicity of soils and vegetation is great due to its ecotonic position. The purpose of this work was to study the relationship of vegetation with the characteristics of cryogenic soils and the dynamics of the active layer in forest-tundra landscapes. Data were obtained during monitoring studies at key sites in diverse landscapes of forest-tundra in the vicinity of Labytnangi. It was revealed that the thickness of the organogenic horizons, as well as the value of the moss phytomass, determine the active-layer thickness. A close connection with relief and soils allows the use of vegetation as an indicator of the soil texture and the depth of active-layer occurrence and features. Keywords: plant communities, cryogenic soils, active layer, landscape, forest-tundra, Western Siberi