Double-exciton component of the cyclotron spin-flip mode in a quantum Hall ferromagnet

We report on the calculation of the cyclotron spin-flip excitation (CSFE) in a spin-polarized quantum Hall system at unit filling. This mode has a double-exciton component which contributes to the CSFE correlation energy but can not be found by means of a mean field approach. The result is compared with available experimental data.Comment: 9 pages, 2 figure

Investigation of the influence of carbon alloying on structure formation and thermal properties of new carbon-containing superinvar alloys

В работе изучены суперинварные сплавы на Fe-Ni-Co основе с дополнительным легированием углеродом в широком диапазоне (0,6%, 0,8% и 1,7% С). По результатам металлографического анализа показано, что графит распространен по всему объёму шлифа в мелкодисперсном состоянии, причем при повышении содержания в сплаве графитные включения становятся крупнее. Показано, что после термических обработок по режимам отжига (680С, 3ч; 800С, 3ч), закалки в воду от 860С и закалки в воду от 860С с последующим низкотемпературным отпуском (315 С, 1,5ч) может происходить изменение морфологии графитных включений. По результатам термического анализа предложено повышать температуру отжига до 800С с целью более полного завершения процессов графитизации. Также показано, что после отжига по режиму 800С, 3ч анализируемые сплавы проявляют минимальные значения температурного коэффициента линейного расширения (20-100 < 1,510-6К-1).Super-invar alloys based on Fe-Ni-Co with additions of carbon in wide range (0,6%, 0,8% and 1,7% С) have been investigated. Metallography analysis showed that graphite phase distributed throughout the volume of alloy in a fine state. Moreover, the size of graphite inclusions rises with the increasing of the total contents of carbon. It is showed, that after a heat treatment the morphology of graphite phases may change. Thermal analysis revealed that it is necessary to up the temperature of annealing unto 800С because at that temperature the graphitization processes proceeds more fully. It is also showed that after annealing (800С, 3h) investigated alloys induce minimal thermal expansion (20-100 < 1,510-6К-1).Программа развития УрФУ на 2013 год (п.2.1.1.1

Crystallography of grain refinement in cast zinc-copper alloys

Adding the peritectic forming element Cu effectively reduced the average grain size of cast Zn by over 85%. At a specified cast condition, the smallest grain size was obtained at 2wt% Cu addition. A further increase in Cu content led to grain coarsening in the cast Zn-Cu alloys. Although the solute effect of Cu was predominately responsible for the grain refinement through restriction of the grain growth, it was found that the variation of grain size is also closely related to the formation of the pro-peritectic phase, -CuZn4. Crystallographic calculations using the edge-to-edge matching model showed low interatomic misfit and interplanar mismatch between Zn and the -CuZn4 phase. In addition, a reproducible h.c.p.-h.c.p. (h.c.p. denotes hexagonal close-packed) orientation relationship between Zn and the -CuZn4 particles (located within the Zn grain centres) was also experimentally determined using the electron backscattered diffraction method. This indicated the high potency of the pro-peritectic -CuZn4 particles as effective heterogeneous nucleation sites for η-Zn, which further refined the Zn grains. However, when the Cu content was over 2.0wt%, formation of large -CuZn4 particles resulted in grain coarsening of the cast alloys

Neural Cross-Lingual Named Entity Recognition with Minimal Resources

For languages with no annotated resources, unsupervised transfer of natural language processing models such as named-entity recognition (NER) from resource-rich languages would be an appealing capability. However, differences in words and word order across languages make it a challenging problem. To improve mapping of lexical items across languages, we propose a method that finds translations based on bilingual word embeddings. To improve robustness to word order differences, we propose to use self-attention, which allows for a degree of flexibility with respect to word order. We demonstrate that these methods achieve state-of-the-art or competitive NER performance on commonly tested languages under a cross-lingual setting, with much lower resource requirements than past approaches. We also evaluate the challenges of applying these methods to Uyghur, a low-resource language.Comment: EMNLP 2018 long pape

Stability of Spatio-Temporal Structures in a Lattice Model of Pulse-Coupled Oscillators

We analyze the collective behavior of a lattice model of pulse-coupled oscillators. By studying the intrinsic dynamics of each member of the population and their mutual interactions we observe the emergence of either spatio-temporal structures or synchronized regimes. We perform a linear stability analysis of these structures.Comment: 15 pages, 2 PostScript available upon request at [email protected], Accepted in Physica

MESOLITHIC HUMAN BONES FROM THE UPPER VOLGA BASIN:RADIOCARBON AND TRACE ELEMENTS

Human bones from 3 Mesolithic sites in the Upper Volga basin were analyzed for trace elements, and dated by accelerator mass spectrometry (AMS). The radiocarbon dates of the bones correspond to the Mesolithic era. However, some dates differ from those obtained for the enclosing deposits and for the worked wood fragments in the cultural layer. The elemental composition of the bones is interpreted in terms of increased concentrations of some elements and their impact on human health and behavior.</p