Temperature independent diffuse scattering and elastic lattice deformations in relaxor PbMg1/3Nb2/3O3

The results of diffuse neutron scattering experiment on PbMg1/3Nb2/3O3 single crystal above the Burns temperature are reported. It is shown that the high temperature elastic diffuse component is highly anisotropic in low-symmetry Brillouin zones and this anisotropy can be described using Huang scattering formalism assuming that the scattering originates from mesoscopic lattice deformations due to elastic defects. The qualitative agreement between this model and the experimental data is achieved with simple isotropic defects. It is demonstrated that weak satellite maxima near the Bragg reflections can be interpreted as the finite resolution effect.Comment: 7 pages, 7 figure

Применение кластеризации k-means и анализа гистограмм для автоматизации предварительной обработки изображений дискомицетов, полученных в среде обитания

The study of biological diversity requires a thorough inventory of all groups of organisms, including destructors, among which fungi play a significant role. Discomycetes, a group of orders of fungi of the Ascomycota phylum, require close attention from researchers due to their low level of knowledge. The paper proposes an approach to automating the process of inventory of representatives of this group of orders and presents a prototype of a software package that allows one to identify the presence of fruit bodies of discomycetes in photographs taken in the natural habitat. A feature of the proposed solution is the application of the k-means clustering method, the use of scaled histograms to determine the presence of an image of the fruit body of Discomycetes in this image, and the prospects for using this tool in machine learning are described using neural networks

Low-temperature magnetostriction and distortions in the rare-earth Laves phases

The effects of partial substitution of dysprosium in Tb0.2Dy0.8Co2 by terbium and gadolinium on the structure and magnetic properties have been studied. Two compositions, Tb0.3Dy0.7Co2 and Tb0.2Dy0.7Gd0.1Co2 have been synthesized. Their crystal structure, in contrast to the structure of the original compound, has both tetragonal distortions and rhombohedral distortions at lower temperatures. Anomalies of magnetostriction and magnetocaloric effect near the observed magnetic phase transitions have been studied. The sign-alternating temperature dependences of the longitudinal and transverse magnetostrictions associated with various types of crystal structure distortions of the alloys are revealed

Fabrication and properties of L-arginine-doped PCL electrospun composite scaffolds

The article describes fabrication and properties of composite fibrous scaffolds obtained by electrospinning of the solution of poly({\epsilon}-caprolactone) and arginine in common solvent. The influence of arginine content on structure, mechanical, surface and biological properties of the scaffolds was investigated. It was found that with an increase of arginine concentration diameter of the scaffold fibers was reduced, which was accompanied by an increase of scaffold strength and Young modulus. It was demonstrated that porosity and water contact angle of the scaffold are independent from arginine content. The best cell adhesion and viability was shown on scaffolds with arginine concentration from 0.5 to 1 % wt

Large Angle Hadron Correlations from Medium-Induced Gluon Radiation

Final state medium-induced gluon radiation in ultradense nuclear matter is examined and shown to favor large angle emission when compared to vacuum bremsstrahlung due to the suppression of collinear gluons. Perturbative expression for the contribution of its hadronic fragments to the back-to-back particle correlations is derived. It is found that in the limit of large jet energy loss gluon radiation determines the yield and angular distribution of | Delta phi | > Pi/2 di-hadrons to transverse momenta pT2 of the associated particles. Clear transition from enhancement to suppression of the away-side hadron correlations is established at moderate pT2 and its experimentally accessible features are predicted versus the trigger particle momentum pT1.Comment: 5 pages, 3 figures. Figures 1 and 2 and some of the text revised. Footnote added. As published in Phys. Lett.

Structural heterogeneity and diffuse scattering in morphotropic lead zirconate-titanate single crystals

Complementary diffuse and inelastic synchrotron X-ray scattering measurements of lead zirconate-titanate single crystals with composition near the morphotropic phase boundary (x=0.475) are reported. In the temperature range 293 K < T < 400 K a highly anisotropic quasielastic diffuse scattering is observed. Above 400 K this scattering disappears. Its main features can be reproduced by model of inhomogeneous lattice deformations caused by inclusions of a tetragonal phase into a rhombohedral or monoclinic phase. This observation supports the idea that PZT at its morphotropic phase boundary is essentially structurally inhomogeneous.Comment: 4 pages, 4 figure