Polarization bremsstrahlung by fast charge on atomic bound electrons—Analog of nuclear M¨ossbauer’s effect

Features of polarization bremsstrahlung radiation (PB) by a relativistic charge on medium electrons bound in atoms are discussed. PB is considered as a dispersion of virtual photons of an electromagnetic field of a fast charge on atomic bound electrons. In this case atomic electron can get dispersed at a recoil energy in only certain portions, as in the nuclear M¨ossbauer process. Because of this a spectrum of dispersed photons is degenerated in a series of narrow peaks

Angular variation of the magnetoresistance of the superconducting ferromagnet UCoGe

We report a magnetoresistance study of the superconducting ferromagnet UCoGe. The data, taken on single-crystalline samples, show a pronounced structure at $B^* = 8.5$~T for a field applied along the ordered moment $m_0$. Angle dependent measurements reveal this field-induced phenomenon has an uniaxial anisotropy. Magnetoresistance measurements under pressure show a rapid increase of $B^*$ to 12.8~T at 1.0~GPa. We discuss $B^*$ in terms of a field induced polarization change. Upper critical field measurements corroborate the unusual S-shaped $B_{c2}(T)$-curve for a field along the $b$-axis of the orthorhombic unit cell.Comment: 6 pages, 5 figures; accepted for publication in Phys. Rev.

Method for obtaining ingots of the A34 solder based on an investigation into the relation between the structure and properties of liquid and solid metals

A comparative analysis of the influence of the modifying method on the structure and phase composition of the ingots of the A34 solder is performed. Modification is performed by force of heating the melt to 1000°C and introducing the fine-crystalline remelt in an amount of 5% of the charge amount into the melt. The investigation is performed using DTA and metallographic analysis. The structure of the ingot of the A34 solder is additionally investigated at elevated temperatures (150 and 300°C) by the sc-AFM method using the NTEGRA Therma probe nanolaboratory, and recommendations are given to optimize the modes of casting and thermal treatment. © 2013 Allerton Press, Inc

Superconductivity and magnetic order in the non-centrosymmetric Half Heusler compound ErPdBi

We report superconductivity at $T_c = 1.22$ K and magnetic order at $T_N = 1.06$ K in the semi-metallic noncentrosymmetric Half Heusler compound ErPdBi. The upper critical field, $B_{c2}$, has an unusual quasi-linear temperature variation and reaches a value of 1.6 T for $T \rightarrow 0$. Magnetic order is found below $T_c$ and is suppressed at $B{_M} \sim 2.5$ T for $T \rightarrow 0$. Since $T_c \simeq T_N$, the interaction of superconductivity and magnetism is expected to give rise to a complex ground state. Moreover, electronic structure calculations show ErPdBi has a topologically nontrivial band inversion and thus may serve as a new platform to study the interplay of topological states, superconductivity and magnetic order.Comment: 6 pages, 5 figures; accepted for publication in Europhysics Letter

O campo problemático das práticas de comunicação no contexto da globalização: o aspecto linguístico

The article examines the features of modern communication that are greatly influenced by globalization and new information communication technologies. Against this background the virtualization of communicative space accelerated in modern civilization. The role of language in the system of culture codes at the present stage of globalization was analysed. It is argued that accumulation and reproduction of socio-cultural experience, implementation of spiritual and moral continuity, and preservation of the defining signs of ethno-cultural identity are associated with the increasing role of language in the execution of these processes and in the preservation and reproduction of the specific nature of ethnic cultures.Aquí se analizan los rasgos de comunicación moderna que estan muy afectados por la globalización y tecnologías nuevas de información y comunicación. Las tecnologías acceleran la virtualización del espacio comunicativo de la civilización moderna. Se también el papel del idioma en el sistema de códigos culturales en la fase moderna de globalización. Se muestra que la acumulación y reproducción de experiencias socioculturales, implementación de continuidad moral y espiritual y preservación de características determinantes de identidad cultural étnica se vinculan al papel creciente del idioma en el transcurso de estos procesos y en la preservación y reproducción de la esencia distinta de culturas étnicas.O artigo examina as características dos processos contemporâneos de comunicação, altamente expostos à globalização e as novas tecnologias de informação e comunicação, através das quais a virtualização do espaço de comunicação da civilização moderna se acelera; está a ser analisado o papel de linguagem no sistema de códigos culturais na fase atual da globalização; prova-se que existe uma ligação entre a acumulação e reprodução de experiência sociocultural, a realização de continuidade espiritual e moral e preservação dos atributos de identidade etnocultural, e o papel crescente de linguagem em implementação destes processos, em preservação e reprodução das características específicas de culturas nacionais

Optimal processing of noisy images in a photodetector with limited dynamic range

A study aimed at optimizing noisy image processing under conditions of strong additive noise has been performed. An algorithm of optimal signal processing was developed and a possibility of improving image quality due to the subtraction of excess additive noise (which limits the photodetector dynamic range) was substantiated. The possibility of technical implementation of noise subtraction due to forced recombination of charge carriers in the photodetector is experimentally confirmed. The proposed approach to design processing systems makes it possible to improve the quality of recorded images under noisy conditions without any changes in the photodetector desig