63 research outputs found
Formation of quasi-periodic nano- and microstructures on silicon surface under IR and UV femtosecond laser pulses
Quasi-periodic nano- and microstructures have been formed on silicon surface using IR ( λ ≈ 744 nm) and UV ( λ ≈ 248 nm) femtosecond laser pulses. The influence of the incident laser fluence and the number of pulses on the structured surface topology has been investigatedyesBelgorod State Universit
Surface texturing of steel by femtosecond laser and accompanying structure/ phase transformations
Topography, structure, and phase composition of surface layers of AISI 321 stainless steel textured by 1030-nm 320-fs-laser pulses were studied by scanning electron microscopy and X-ray diffraction analysis. Variation in single-pulse fluence and the number of pulses was found to change the laser-produced surface texture from onedimensional quasi-periodic nanograting to microrelief of various roughnes
Regularities of formation and degradation of the microstructure and properties of new ultrafine-grained low-modulus Ti-Nb-Mo-Zr alloys
Regularities of the formation of ultrafine-grained (UFG) and submicrocrystalline (SMC) structures in new nickel-free low-modulus Ti-Nb-Mo-Zr titanium β alloys under the action of plastic deformation have been studied. Temperature-time ranges of the development of dynamic recrystallization processes under the simultaneous action of temperature and plastic deformation are determined. A type-II recrystallization diagram of the Ti-28Nb-8Mo-12Zr alloy is constructed and analyze
ЧИСЛЕННОЕ МОДЕЛИРОВАНИЕ ГРУНТОВЫХ СРЕД
The authors have created the numerical realization of a variant of finite element method to detect shifts and tensions in the soil mass. The software is based on mathematical apparatus of Fourier transform of compact functions.Разработана численная реализация варианта метода конечных элементов для определения перемещений и напряжений в массиве грунта. Программный комплекс построен на базе математического аппарата преобразования Фурье финитных функций
High-pressure effects on structural, magnetic, and vibrational properties of van der Waals antiferromagnet MnPS₃
The crystal structure, vibrational spectra, and magnetic structure of quasi-two-dimensional layered van der Waals material MnPS3 were studied using x-ray diffraction and Raman spectroscopy at high pressures up to 28 GPa, and neutron diffraction up to 3.6 GPa, respectively. A structural phase transition between two monoclinic modifications of the same C2/m symmetry was observed, evolving gradually in the pressure range of about 1–6 GPa. The transition is accompanied by abrupt shortening of lattice parameters, significant reduction of the monoclinic distortion, and anomalies in the pressure behavior of several Raman-mode frequencies. No more structural phase transitions were revealed in the studied pressure range. The antiferromagnetic (AFM) state with a propagation vector k= (0, 0, 0) remains stable in ambient pressure and high-pressure structural phases of MnPS3 at least up to 3.6 GPa. The Néel temperature increases noticeably with a pressure coefficient of dTN/dP=6.7 K/GPa, leading to modification of the dominant first-neighbor magnetic interaction exchange parameter with a relevant coefficient dJ1/dP≈−0.6 meV/GPa. This observation is in contrast to the pressure behavior of FePS3, demonstrating modification of the AFM state from 2D-like to 3D-like at the similar pressure-induced structural phase transition. The different pressure response of the magnetic states of MnPS3 and FePS3 is analyzed in terms of competing in-plane and interplane magnetic interactions
Synchronization of multi-phase oscillators: An Axelrod-inspired model
Inspired by Axelrod's model of culture dissemination, we introduce and
analyze a model for a population of coupled oscillators where different levels
of synchronization can be assimilated to different degrees of cultural
organization. The state of each oscillator is represented by a set of phases,
and the interaction --which occurs between homologous phases-- is weighted by a
decreasing function of the distance between individual states. Both ordered
arrays and random networks are considered. We find that the transition between
synchronization and incoherent behaviour is mediated by a clustering regime
with rich organizational structure, where some of the phases of a given
oscillator can be synchronized to a certain cluster, while its other phases are
synchronized to different clusters.Comment: 6 pages, 5 figure
CGAT-core: a python framework for building scalable, reproducible computational biology workflows
In the genomics era computational biologists regularly need to process, analyse and integrate large and complex biomedical datasets. Analysis inevitably involves multiple dependent steps, resulting in complex pipelines or workflows, often with several branches. Large data volumes mean that processing needs to be quick and efficient and scientific rigour requires that analysis be consistent and fully reproducible. We have developed CGAT-core, a python package for the rapid construction of complex computational workflows. CGAT-core seamlessly handles parallelisation across high performance computing clusters, integration of Conda environments, full parameterisation, database integration and logging. To illustrate our workflow framework, we present a pipeline for the analysis of RNAseq data using pseudo-alignment
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