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showing 10 items of 2156 documents
Hydrogen Formation on Phase Boundaries of Sn/Al
2002
The present paper continues our earlier study of the embrittlement of Sn-Al eutectic alloy in water vapor and hydrogen emission from it, Atomically clean interfaces of solid phase joints of Sn with Al served as simple phase boundary models for this system. It was found by SIMS, X-ray and SEM techniques that the brittleness is caused by chemical adsorption of hydrogen on phase boundaries. This process is facilitated by structural defects. The reaction of hydrogen with phase boundary occurs first in regions of micro-and submicrocracks. The effect is irreversible one and it is associated with the formation of SnH4 that is instable and decomposes at the room temperature. The phase boundary of S…
Polymorphic and regular localized activity structures in a two-dimensional two-component reaction–diffusion lattice with complex threshold excitation
2010
Abstract Space–time dynamics of the system modeling collective behaviour of electrically coupled nonlinear units is investigated. The dynamics of a local cell is described by the FitzHugh–Nagumo system with complex threshold excitation. It is shown that such a system supports formation of two distinct kinds of stable two-dimensional spatially localized moving structures without any external stabilizing actions. These are regular and polymorphic structures. The regular structures preserve their shape and velocity under propagation while the shape and velocity as well as other integral characteristics of polymorphic structures show rather complex temporal behaviour. Both kinds of structures r…
Supplementary optical phase transition in photorefractive coherent oscillator
2001
The semilinear photorefractive coherent oscillator with two counterpropagating pump waves may exhibit two optical phase transitions: one from a disordered state of wide-angle photorefractive scattering into a high-ordered state with the immobile photorefractive grating and the other one from the state with immobile grating into the state with two moving photorefractive gratings. We show, both experimentally and from calculations, that two these phase transitions are the second-order phase transitions.
Dis-Identity: New Forms of Identity and Psychopathology—Socioanthropological Changes and Self-Development
2014
The passage from modernity to postmodernity deeply upset the group dimension, and, consequently, personal identity itself. Transformations involving the entire planet, socioanthropological changes our society had to cope with, are producing a change in the dynamics of identity formation and the appearance of new psychopathological figures. The loss of cohesion of the sense of belonging and the weak internalization process of the elements that form the individual identity (cultural, linguistic, religious traditions, etc.) draw an essentially uncertain and temporary existence. Drawing on some themes of subjectual group analysis theory of personality, the article proposes the concept of dis-id…
Hypersensitive tunable Josephson escape sensor for gigahertz astronomy
2020
Sensitive photon detection in the gigahertz band constitutes the cornerstone to study different phenomena in astronomy, such as radio burst sources, galaxy formation, cosmic microwave background, axions, comets, gigahertz-peaked spectrum radio sources and supermassive black holes. Nowadays, state of the art detectors for astrophysics are mainly based on transition edge sensors and kinetic inductance detectors. Overall, most sensible nanobolometers so far are superconducting detectors showing a noise equivalent power (NEP) as low as 2x10-20 W/Hz1/2. Yet, fast thermometry at the nanoscale was demonstrated as well with Josephson junctions through switching current measurements. In general, det…
Clues on the Milky Way disc formation from population synthesis simulations
2016
Toward Understanding Rich Superclusters
2008
We present a morphological study of the two richest superclusters from the 2dF Galaxy Redshift Survey (SCL126, the Sloan Great Wall, and SCL9, the Sculptor supercluster). We use Minkowski functionals, shapefinders, and galaxy group information to study the substructure of these superclusters as formed by different populations of galaxies. We compare the properties of grouped and isolated galaxies in the core region and in the outskirts of superclusters. The fourth Minkowski functional $V_3$ and the morphological signature $K_1$- $K_2$ show a crossover from low-density morphology (outskirts of supercluster) to high-density morphology (core of supercluster) at mass fraction $m_f \approx 0.7$.…
Spectroscopic Confirmation of an Ultramassive and Compact Galaxy at z = 3.35: a Detailed Look at an Early Progenitor of Local Giant Ellipticals
2014
et al.
Temporal Soliton “Molecules” in Mode-Locked Lasers: Collisions, Pulsations, and Vibrations
2008
A few years after the discovery of the stable dissipative soliton pairs in passively mode-locked lasers, a large variety of multi-soliton complexes were studied in both experiments and numerical simulations, revealing interesting new behaviors. This chapter focuses on the following three subjects: collisions between dissipative solitons, pulsations of dissipative solitons, and vibrations of soliton pairs. Different outcomes of collisions between a soliton pair and a soliton singlet are discussed, showing possible experimental control in the formation or dissociation of ‘soliton molecules’. Long-period pulsations of single and multiple dissipative solitons are presented as limit cycles and o…
Spectral incoherent solitons
2009
Solitons have been usually considered as inherently coherent localized structures and the discovery of incoherent optical solitons has represented a significant progress [1]. As occurs for standard coherent solitons, incoherent solitons are characterized by a confinement of the field in the spatial or in the temporal domain. We introduce here a novel type of incoherent solitons that are neither spatial nor temporal, i.e., the incoherent field does not exhibit any confinement in the spatiotemporal domain; however, the uncorrelated frequency components that constitute the incoherent field exhibit a localized soliton behavior in the frequency domain [2].