Dynamic Stabilization of Cubic AuZn

A recently developed temperature-dependent effective potential method is employed to study the martensitic phase transformation in AuZn. This method is based on ab initio molecular dynamics and allows to obtain finite-temperature lattice vibrational properties. We show that the transversal acoustic TA_2[110] mode associated with the phase transition is stabilized at 300 K. Temperature evolution of single-phonon dynamic structure factor at the wave vector q=1/3[1,1,0], associated with phonon softening and Fermi surface nesting, was also studied

Hyperbolic chaos in self-oscillating systems based on mechanical triple linkage: Testing absence of tangencies of stable and unstable manifolds for phase trajectories

Dynamical equations are formulated and a numerical study is provided for self-oscillatory model systems based on the triple linkage hinge mechanism of Thurston -- Weeks -- Hunt -- MacKay. We consider systems with holonomic mechanical constraint of three rotators as well as systems, where three rotators interact by potential forces. We present and discuss some quantitative characteristics of the chaotic regimes (Lyapunov exponents, power spectrum). Chaotic dynamics of the models we consider are associated with hyperbolic attractors, at least, at relatively small supercriticality of the self-oscillating modes; that follows from numerical analysis of the distribution for angles of intersection of stable and unstable manifolds of phase trajectories on the attractors. In systems based on rotators with interacting potential the hyperbolicity is violated starting from a certain level of excitation.Comment: 30 pages, 18 figure

Aspects of a multi-level study of competitive performance of objects and subjects of economic management

This article discusses the questions of analysis and evaluation of competitive performance at different levels of the economic system. It substantiates the separation of a micro-level study of competitive performance of objects and subjects of economic management. It introduces a new product level. Great attention is given to formalization of the competitive performance indicator for objects and subjects at the product, micro-, meso- and macro-levels. It is shown that competitive performance of products and services is studied at the product level, competitive performance of companies and enterprises is studied at the micro-level, competitive performance of industry sectors, various company associations, etc. is studied at the meso-level and competitive performance of national economies, countries, regions, etc. is studied at the macro-level. © IDOSI Publications, 2013

Impact of Mn-Pn intermixing on magnetic properties of an intrinsic magnetic topological insulator: the µSR perspective

We investigated the magnetic properties of polycrystalline samples of the intrinsic magnetic topological insulators MnPn2Te4, with pnictogen Pn = Sb, Bi, by bulk magnetization and μSR. DC susceptibility detects the onset of magnetic ordering at TN = 27 K and 24 K and a field dependence of the macroscopic magnetization compatible with ferri- (or ferro-) and atiferro- magnetic ordering, respectively. Weak transverse field (wTF) Muon Spin Rotation (μSR) confirms the homogeneous bulk nature of magnetic ordering at the same two distinct transition temperatures. Zero Field (ZF) μSR shows that the Sb based material displays a broader distribution of internal field at the muon, in accordance with a larger deviation from the stoichiomectric composition and a higher degree of positional disorder (Mn at the Pn(6c) site), which however does not affect significantly the sharpness of the thermodynamic transition, as detected by the muon magnetic volume fraction and the observability of a critical divergence in the longitudinal and transverse muon relaxation rates

Evaluation of commercial traits in the accessions of Medicago sativa L. from Asia Minor

Background. One of the main tasks of the present-day breeding practice is the development of high-yielding intensive-type fodder crop cultivars for indoor feeding of livestock. Alfalfa, as a productive and high-protein crop, deserves special attention. An offer of new breeding sources would enable breeders to broaden the diversity of alfalfa cultivars. Objective. The present study involved 65 local varieties and wild accessions of alfalfa from Turkey preserved in the VIR collection. Material and methods. Yekaterinino Experiment Station of VIR (Tambov Province) was chosen as the research site. Evaluation of the alfalfa collection was carried out in 2015–2017, using the methods developed at VIR for fodder crop research targeted at such traits as green biomass yield, seed productivity, and leafiness. The cultivar ‘Marusinskaya 425’ was used as the reference. Results and conclusions. In 2015, four accessions were identified as promising for their green matter yield and seed productivity: local varieties k-3373 and k-3378 from Konya Province, k-5992 from Isparta Province, and k-6116 from Sivas Province. In 2016, three accessions exceeded the reference in the yield of green matter, and three accessions had higher seed productivity. Eight accessions surpassed the reference in leafiness. In 2017, only one accession, k-6009 (Kayseri Province), significantly exceeded the reference in green matter yield. Nine accessions were selected for their high seed yield. The maximum seed productivity was observed in the accession k-3379 (Konya). Leafiness was notably higher than the reference’s in 15 accessions. The average for three years shows that none of the accessions credibly surpassed the reference in green matter yield. Four accessions had higher seed productivity than the reference. According to the three-year average, 11 accessions exceeded the reference in leafiness. All in all, in the three years of study, the accessions k-3373, k-3378 and k-3379 (Konya) were selected for high green matter yield and seed productivity. High seed productivity and leafiness, with satisfactory green matter yield, were registered in the accession k-5992 (Isparta). The accession k-6009 (Kayseri) significantly exceeded the reference in green matter yield, but demonstrated low seed productivity and poor leafiness. The place of origin for the identified local accessions had been Central Anatolia, with its continental climate. These accessions are valuable breeding sources with noteworthy commercial traits. Alfalfa from Asia Minor can be recommended for use in breeding practice, targeted at the development of new high-yielding intensive-type cultivars

Hourly average values of solar wing parameters (flow rate and ion temperatures) according to data of measurements of the Venera-9 and Venera-10 automatic interplanetary stations on an Earth-Venus during the period June 1975 - April 1976

Four electrostatic analyzers with channel electron multipliers as detectors were used to measure solar wind ionic flow. The axes of the fields of vision of two of these analyzers were directed along the axis of the automatic interplanetary station, oriented towards the Sun, while the other two were turned in one plane at angles of +15 deg and -15 deg. The full hemisphere of the angular diagram of each analyzer was approximately 5 deg. The energetic resolution was approximately 6%, and the geometric energy was 0.002 sq cm ave. keV. Each analyzer covered an energetic range of approximately 10 in eight energetic intervals. Spectral distributions were processed in order to obtain the velocity and temperature of the protons. Tabular data show the hour interval (universal time) and the average solar wind velocity in kilometers per second

Gastric Microbiota and Morphological Changes of the Gastroduodenal Tract Associated with Helicobacter Pylori Infection

© 2016, Springer Science+Business Media New York.Investigation of the microbiota at morphological changes of a gastrointestinal tract. One hundred four patients were examined by cytologic, bacteriological methods, and mass-spectrometry techniques. Studying of the microbial association of stomach has demonstrated the mixed microflora presented by Helicobacter pylori, cocci, fungi Candida, rods, and protozoa. Bacteria of the following species were found: Actinomyces, Arthrobacter, Bacillus, Corynebacterium, Lactobacillus, Neisseria, Pseudomonas, Rothia, Staphylococcus, Streptococcus, and Streptomyces. The microbial flora of esophageal samples was less various (opportunistic bacteria Neisseria, Gemella, and Rothia mucilaginosa were revealed). In group of Helicobacter-positive patients, bacteria were found in fungi Candida, Colletotrichum, and bacterias Thauera and Mycoplasma, while in H.pylori-negative patients, samples have more different species. Intensity of morphological changes (the atrophy, the intestinal metaplasia, and the dysplasia) correlated with a frequency of detection of H. pylori and eukaryotic microbiota (fungi Candida and protozoa)

THE RESULTS OF THE STUDY OF VARIETIES OF ALFALFA IN THE CENTRAL-CHERNOZEM ZONE

Three-year study of one hundred world collection of alfalfa was conducted in Central Black-Earth zone of Russia. The varieties of Medicago × varia ‘Zheltogibridnaya 99’, ‘Flora 2’, ‘Karlygash’ and ‘№ 152’ (hybrid ‘Severnaya hybridnaya’ בAugune II’) were recommended for breeding programs. The most variable were character of seed production, productivity of green mass and hay yield productivity; character of foliage and the intensity of regrowth of plants on the 20-th day after spring regrowth had medium variability. The height before the first mowing and height in the phase of full flowering had low variability. There was a significant correlation between the yield of green mass and hay, the yield of green mass and intensity of regrowth and a weak negative correlation between the yield of green mass and seed yield

All-thermal switching of amorphous Gd-Fe alloys: Analysis of structural properties and magnetization dynamics

In recent years, there has been an intense interest in understanding the microscopic mechanism of thermally induced magnetization switching driven by a femtosecond laser pulse. Most of the effort has been dedicated to periodic crystalline structures while the amorphous counterparts have been less studied. By using a multiscale approach, i.e. first-principles density functional theory combined with atomistic spin dynamics, we report here on the very intricate structural and magnetic nature of amorphous Gd-Fe alloys for a wide range of Gd and Fe atomic concentrations at the nanoscale level. Both structural and dynamical properties of Gd-Fe alloys reported in this work are in good agreement with previous experiments. We calculated the dynamic behavior of homogeneous and inhomogeneous amorphous Gd-Fe alloys and their response under the influence of a femtosecond laser pulse. In the homogeneous sample, the Fe sublattice switches its magnetization before the Gd one. However, the temporal sequence of the switching of the two sublattices is reversed in the inhomogeneous sample. We propose a possible explanation based on a mechanism driven by a combination of the Dzyaloshiskii-Moriya interaction and exchange frustration, modeled by an antiferromagnetic second-neighbour exchange interaction between Gd atoms in the Gd-rich region. We also report on the influence of laser fluence and damping effects in the all-thermal switching