65,633 research outputs found
Deformation-strain field in Sichuan and its surrounding areas based on GPS data
AbstractThe strain rate in Sichuan and its surrounding areas, and the activity rate and strain rate in two block boundary fault zones were calculated according to the block movement parameters estimated using the station speed obtained from regional GPS station observation data in these areas for 2009–2011 and GPS continuous station data for 2011–2013. The movement field characteristics in these areas were analyzed with the Sichuan Basin as the reference. Results show that the principal strain rate and maximum shear strain rate of the Bayan Har block were the largest, followed by those of the Sichuan–Yunnan block and Sichuan Basin. The deep normal strain rate in the Longmenshan fault zone was compressive and large over the study period. The normal strain rate in the Xianshuihe fault zone was tensile
Direct observation of pitting corrosion evolutions on carbon steel surfaces at the nano-to-micro- scales.
The Cl--induced corrosion of metals and alloys is of relevance to a wide range of engineered materials, structures, and systems. Because of the challenges in studying pitting corrosion in a quantitative and statistically significant manner, its kinetics remain poorly understood. Herein, by direct, nano- to micro-scale observations using vertical scanning interferometry (VSI), we examine the temporal evolution of pitting corrosion on AISI 1045 carbon steel over large surface areas in Cl--free, and Cl--enriched solutions. Special focus is paid to examine the nucleation and growth of pits, and the associated formation of roughened regions on steel surfaces. By statistical analysis of hundreds of individual pits, three stages of pitting corrosion, namely, induction, propagation, and saturation, are quantitatively distinguished. By quantifying the kinetics of these processes, we contextualize our current understanding of electrochemical corrosion within a framework that considers spatial dynamics and morphology evolutions. In the presence of Cl- ions, corrosion is highly accelerated due to multiple autocatalytic factors including destabilization of protective surface oxide films and preservation of aggressive microenvironments within the pits, both of which promote continued pit nucleation and growth. These findings offer new insights into predicting and modeling steel corrosion processes in mid-pH aqueous environments
Diffuse Neutron Scattering Study of Relaxor Ferroelectric (1-x)Pb(Zn1/3Nb2/3)O3-xPbTiO3(PZN-xPT)
Diffuse neutron scattering is a valuable tool to obtain information about the
size and orientation of the polar nanoregions that are a characteristic feature
of relaxor ferroelectrics. In this paper, we present new diffuse scattering
results obtained on Pb(Zn1/3Nb2/3)O3 (PZN for short) and
(1-x)Pb(Zn1/3Nb2/3)O3-xPbTiO3(PZN-xPT)single crystals (with x=4.5 and 9%),
around various Bragg reflections and along three symmetry directions in the
[100]-[011] zone. Diffuse scattering is observed around reflections with mixed
indices, (100), (011) and (300), and along transverse and diagonal directions
only. No diffuse scattering is found in longitudinal scans. The diffuse
scattering peaks can be fitted well with a Lorentzian function, from which a
correlation length is extracted. The correlation length increases with
decreasing temperatures down to the transition at Tc, first following a
Curie-Weiss law, then departing from it and becoming flat at very low
temperatures. These results are interpreted in terms of three temperature
regions: 1) dynamic polarization fluctuations (i.e. with a finite lifetime) at
high temperatures, 2) static polarization reorientations (condensation of polar
nanoregions) that can still reorient as a unit (relaxor behavior) at
intermediate temperatures and 3) orientational freezing of the polar
nanoregions with random strain fields in pure PZN or a structural phase
transition in PZN-xPT at low temperatures. The addition of PT leads to a
broadening of the diffuse scattering along the diagonal ([111]) relative to the
transverse ([100]) direction, indicating a change in the orientation of the
polar regions. Also, with the addition of PT, the polar nanoregions condense at
a higher temperature above Tc.Comment: AIP 6x9 style files, 9 pages, 5 figures, Conference-Fundamental
Physics of Ferroelectrics 200
Globalizing Hayden White
This conversation originated in a plenary session organized by Ewa DomaÅ„ska and MarÃa Inés La Greca under the same title of ‘Globalizing Hayden White’ at the III International Network for Theory of History Conference ‘Place and Displacement: The Spacing of History’ held at Södertörn University, Stockholm, in August 2018. In order to pay homage to Hayden White’s life work 5 months after his passing we knew that what was needed–and what he himself would have wanted–was a vibrant intellectual exchange. Our ‘celebration by discussion’ contains elaborated and revised versions of the presentations by scholars from China (Xin Chen), Latin America (MarÃa Inés La Greca, Veronica Tozzi Thompson), United States (Paul Roth), Western (Kalle Pihlainen) and East-Central Europe (Ewa DomaÅ„ska). We took this opportunity of gathering scholars who represent different parts of the world, different cultures and approaches to reflect on White’s ideas in a global context. Our interest was in discussing how his work has been read and used (or even misread and misused) and how it has influenced theoretical discussions in different parts of the globe. Rather than just offering an account as experts, we mainly wanted to reflect on the current state of our field and the ways that White’s inheritance might and should be carried forward in the future.Fil: Domanska, Ewa. Adam Mickiewicz University in PoznaÅ„; PoloniaFil: la Greca, MarÃa Inés. Consejo Nacional de Investigaciones CientÃficas y Técnicas; Argentina. Universidad Nacional de Tres de Febrero. Departamento de MetodologÃa, EstadÃstica y Matemáticas; Argentina. Universidad de Buenos Aires. Facultad de FilosofÃa y Letras. Departamento de FilosofÃa; ArgentinaFil: Roth, Paul A.. University of California at Santa Cruz; Estados UnidosFil: Chen, Xin. Zhejiang University; ChinaFil: Tozzi, MarÃa Verónica. Consejo Nacional de Investigaciones CientÃficas y Técnicas; Argentina. Universidad Nacional de Tres de Febrero. Departamento de MetodologÃa, EstadÃstica y Matemáticas; Argentina. Universidad de Buenos Aires. Facultad de FilosofÃa y Letras. Departamento de FilosofÃa; ArgentinaFil: Pihlainen, Kalle. Tallinn University; Estoni
Three-Nucleon Continuum by means of the Hyperspherical Adiabatic Method
This paper investigates the possible use of the Hyperspherical Adiabatic
basis in the description of scattering states of a three-body system. In
particular, we analyze a 1+2 collision process below the three-body breakup.
The convergence patterns for the observables of interest are analyzed by
comparison to a unitary equivalent Hyperspherical Harmonic expansion.
Furthermore, we compare and discuss two different possible choices for
describing the asymptotic configurations of the system, related to the use of
Jacobi or hyperspherical coordinates. In order to illustrate the difficulties
and advantages of the approach two simple numerical applications are shown in
the case of neutron-deuteron scattering at low energies using s-wave
interactions. We found that the optimization driven by the Hyperspherical
Adiabatic basis is not as efficient for scattering states as in bound state
applications.Comment: 29 pages, 5 figures, accepted for publication in Few-Body Systems (in
press
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