1,337 research outputs found
Examining the Influence of Time-Use Preferences on Technology Acceptance: The Role of Computer Polychronicity
Past research recognizes the important influence of individual beliefs on technology acceptance and use. This line of research has also identified a variety of factors that drive the formation of these beliefs. One category of variables that has not received much attention in this research stream consists of individual preferences, in particular time-use preferences. In the current study we add to the literature on technology acceptance, and belief formation in particular, by introducing and empirically testing a new construct labeled computer polychronicity, which captures individualsâ time-use preferences regarding IT. Computer polychronicity is positioned in this study as a key driver of perceived usefulness, mediating the effects of computer anxiety and computer playfulness. Overall, the results support the notion that preferences play important roles in the formation of technology-related beliefs
Correlation of conductivity and angle integrated valence band photoemission characteristics in single crystal iron perovskites for 300 K < T < 800 K: Comparison of surface and bulk sensitive methods
A single crystal monolith of La0.9Sr0.1FeO3 and thin pulsed laser deposited
film of La0.8Sr0.2Fe0.8Ni0.2O3 were subject to angle integrated valence band
photoemission spectroscopy in ultra high vacuum and conductivity experiments in
ambient air at temperatures from 300 K to 800 K. Except for several sputtering
and annealing cycles, the specimen were not prepared in-situ.. Peculiar changes
in the temperature dependent, bulk representative conductivity profile as a
result of reversible phase transitions, and irreversible chemical changes are
semi-quantitatively reflected by the intensity variation in the more surface
representative valence band spectra near the Fermi energy. X-ray photoelectron
diffraction images reflect the symmetry as expected from bulk iron perovskites.
The correlation of spectral details in the valence band photoemission spectra
(VB PES) and details of the conductivity during temperature variation suggest
that valuable information on electronic structure and transport properties of
complex materials may be obtained without in-situ preparation
Direct Observation of High-Temperature Polaronic Behavior In Colossal Magnetoresistive Manganites
The temperature dependence of the electronic and atomic structure of the
colossal magnetoresistive oxides (x = 0.3, 0.4) has
been studied using core and valence level photoemission, x-ray absorption and
emission, and extended x-ray absorption fine structure spectroscopy. A dramatic
and reversible change of the electronic structure is observed on crossing the
Curie temperature, including charge localization and spin moment increase of
Mn, together with Jahn-Teller distortions, both signatures of polaron
formation. Our data are also consistent with a phase-separation scenario.Comment: 5 pages, 4 figures, revte
Effect of sintering temperature under high pressure in the uperconductivity for MgB2
We report the effect of the sintering temperature on the superconductivity of
MgB2 pellets prepared under a high pressure of 3 GPa. The superconducting
properties of the non-heated MgB2 in this high pressure were poor. However, as
the sintering temperature increased, the superconducting properties were vastly
enhanced, which was shown by the narrow transition width for the resistivity
and the low-field magnetizations. This shows that heat treatment under high
pressure is essential to improve superconducting properties. These changes were
found to be closely related to changes in the surface morphology observed using
scanning electron microscopy.Comment: 3 Pages including 3 figure
Missed prediction of the neutron halo in Mg
Halo phenomena have long been an important frontier in both experimental and
theoretical nuclear physics. Mg was identified as a halo nucleus in 2014
and remains the heaviest nuclear halo system to date. While the halo phenomenon
in Mg was not predicted before the discovery, its description has been
still challenging afterwards. In this Letter, we report a microscopic,
self-consistent, and density-functional independent description of the neutron
halo in Mg by the deformed relativistic Hartree-Bogoliubov theory in
continuum (DRHBc) that was developed in 2010. The experimental neutron
separation energies and empirical matter radii of neutron-rich magnesium
isotopes as well as the deformed -wave halo characteristics of Mg are
well reproduced without any free parameters. The DRHBc theory investigated only
even-even magnesium isotopes in previous works and for that reason missed
predicting Mg as a halo nucleus before 2014. Although the core and the
halo of Mg are both prolate, higher-order shape decoupling on the
hexadecapole and hexacontatetrapole levels is predicted.Comment: 8 pages, 4 figures, 1 tabl
The Infrared Einstein Ring in the Gravitational Lens MG1131+0456 and the Death of the Dusty Lens Hypothesis
We have obtained and modeled new NICMOS images of the lens system
MG1131+0456, which show that its lens galaxy is an H=18.6 mag, transparent,
early-type galaxy at a redshift of about z_l = 0.85; it has a major axis
effective radius R_e=0.68+/-0.05 arcsec, projected axis ratio b/a=0.77+/-0.02,
and major axis PA=60+/-2 degrees. The lens is the brightest member of a group
of seven galaxies with similar R-I and I-H colors, and the two closest group
members produce sufficient tidal perturbations to explain the ring morphology.
The host galaxy of the MG1131+0456 source is a z_s > 2 ERO (``extremely red
object'') which is lensed into optical and infrared rings of dramatically
different morphologies. These differences imply a strongly wavelength-dependent
source morphology that could be explained by embedding the host in a larger,
dusty disk. At 1.6 micron (H), the ring is spectacularly luminous, with a total
observed flux of H=17.4 mag and a de-magnified flux of 19.3 mag, corresponding
to a 1-2L_* galaxy at the probable source redshift of z_s > 2. Thus, it is
primarily the stellar emission of the radio source host galaxy that produces
the overall colors of two of the reddest radio lenses, MG1131+0456 and
B~1938+666, aided by the suppression of optical AGN emission by dust in the
source galaxy. The dusty lens hypothesis -- that many massive early-type
galaxies with 0.2 < z_l < 1.0 have large, uniform dust opacities -- is ruled
out.Comment: 27 pages, 8 COLOR figures, submitted to ApJ. Black and white version
available at http://cfa-www.harvard.edu/castle
Role of preferential weak hybridization between the surface-state of a metal and the oxygen atom in the chemical adsorption mechanism
We report on the chemical adsorption mechanism of atomic oxygen on the Pt(111) surface using angle-resolved-photoemission spectroscopy (ARPES) and density functional calculations. The detailed band structure of Pt(111) from ARPES reveals that most of the bands near the Fermi level are surface-states. By comparing band maps of Pt and O/Pt, we identify that dxz (dyz) and dz2 orbitals are strongly correlated in the surface-states around the symmetry point M and K, respectively. Additionally, we demonstrate that the s- or p-orbital of oxygen atoms hybridizes preferentially with the dxz (dyz) orbital near the M symmetry point. This weak hybridization occurs with minimal charge transfer
Cuticular protein with a low complexity sequence becomes cross-linked during insect cuticle sclerotization and is required for the adult molt
Citation: Mun, S., Noh, M. Y., Dittmer, N. T., Muthukrishnan, S., Kramer, K. J., Kanost, M. R., & Arakane, Y. (2015). Cuticular protein with a low complexity sequence becomes cross-linked during insect cuticle sclerotization and is required for the adult molt. Scientific Reports, 5, 11. doi:10.1038/srep10484In the insect cuticle, structural proteins (CPs) and the polysaccharide chitin are the major components. It has been hypothesized that CPs are cross-linked to other CPs and possibly to chitin by quinones or quinone methides produced by the laccase2-mediated oxidation of N-acylcatechols. In this study we investigated functions of TcCP30, the third most abundant CP in protein extracts of elytra (wing covers) from Tribolium castaneum adults. The mature TcCP30 protein has a low complexity and highly polar amino acid sequence. TcCP30 is localized with chitin in horizontal laminae and vertically oriented columnar structures in rigid cuticles, but not in soft and membranous cuticles. Immunoblot analysis revealed that TcCP30 undergoes laccase2-mediated cross-linking during cuticle maturation in vivo, a process confirmed in vitro using recombinant rTcCP30. We identified TcCPR27 and TcCPR18, the two most abundant proteins in the elytra, as putative crosslinking partners of TcCP30. RNAi for the TcCP30 gene had no effect on larval and pupal growth and development. However, during adult eclosion, similar to 70% of the adults were unable to shed their exuvium and died. These results support the hypothesis that TcCP30 plays an integral role as a cross-linked structural protein in the formation of lightweight rigid cuticle of the beetle
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