3,850 research outputs found
Cannot Live without Facebook? An Expectation Confirmation Model with the Moderating Effects of Narcissism
Facebook provides an ideal channel for people to admire their own performance. People tend to show off themselves to others and confirming their feedback on Facebook. With behavior on Facebook, narcissism is now highlighted by many researchers. Hence, based on the expectation confirmation theory (ECT), our study looks into continuance Facebook usage behaviors. It explores the relationship between perceived feedback, confirmation, satisfaction, and continuance intentions, and most important of all, it examines the moderating effects of narcissistic traits on these relationships. Data are collected from 420 valid respondents through self-administered questionnaires. Results revealed that: (1) Continuance Facebook behavior intention is jointly influenced by perceived feedback and satisfaction, which in turn is determined by confirmation. Then, confirmation is influenced by perceived feedback; (2) Narcissism has the moderating effect on the relationships between feedback and confirmation as well as confirmation and satisfaction. Finally, interpretations and implication of these findings are discussed
Anomalous electronic Raman scattering in Na_xCoO_2 H_2O
Raman scattering experiments on Na_{x}CoO_2 yH_2O single crystals show a
broad electronic continuum with a pronounced peak around 100 cm-1 and a cutoff
at approximately 560 cm-1over a wide range of doping levels. The electronic
Raman spectra in superconducting and non-superconducting samples are similar at
room temperature, but evolve in markedly different ways with decreasing
temperature. For superconducting samples, the low-energy spectral weight is
depleted upon cooling below T* sim 150K, indicating a opening of a pseudogap
that is not present in non-superconducting materials. Weak additional phonon
modes observed below T* suggest that the pseudogap is associated with charge
ordering.Comment: 5 pages, 4 figures, for further information see www.peter-lemmens.d
The Numerical Solution of Scalar Field for Nariai Case in 5D Ricci-flat SdS Black String Space with Polynomial Approximation
As one exact candidate of the higher dimensional black hole, the 5D
Ricci-flat Schwarzschild-de Sitter black string space presents something
interesting. In this paper, we give a numerical solution to the real scalar
field around the Nariai black hole by the polynomial approximation. Unlike the
previous tangent approximation, this fitting function makes a perfect match in
the leading intermediate region and gives a good description near both the
event and the cosmological horizons. We can read from our results that the wave
is close to a harmonic one with the tortoise coordinate. Furthermore, with the
actual radial coordinate the waves pile up almost equally near the both
horizons.Comment: 8 pages, 4 figure
New Analytical Formula for Supercritical Accretion Flows
We examine a new family of global analytic solutions for optically thick
accretion disks, which includes the supercritical accretion regime. We found
that the ratio of the advection cooling rate, , to the viscous
heating rate, , i.e., , can be
represented by an analytical form dependent on the radius and the mass
accretion rate. The new analytic solutions can be characterized by the
photon-trapping radius, \rtrap, inside which the accretion time is less than
the photon diffusion time in the vertical direction; the nature of the
solutions changes significantly as this radius is crossed. Inside the trapping
radius,
approaches , which corresponds to the advection-dominated
limit (), whereas outside the trapping radius, the radial dependence
of changes to , which corresponds to the
radiative-cooling-dominated limit. The analytical formula for derived here
smoothly connects these two regimes. The set of new analytic solutions
reproduces well the global disk structure obtained by numerical integration
over a wide range of mass accretion rates, including the supercritical
accretion regime. In particular, the effective temperature profiles for our new
solutions are in good agreement with those obtained from numerical solutions.
Therefore, the new solutions will provide a useful tool not only for evaluating
the observational properties of accretion flows, but also for investigating the
mass evolution of black holes in the presence of supercritical accretion flows.Comment: 14 pages, 7 figures, accepted for publication in the Astrophysical
Journa
Fermion Pairing Dynamics in the Relativistic Scalar Plasma
Using many-body techniques we obtain the time-dependent Gaussian
approximation for interacting fermion-scalar field models. This method is
applied to an uniform system of relativistic spin-1/2 fermion field coupled,
through a Yukawa term, to a scalar field in 3+1 dimensions, the so-called
quantum scalar plasma model. The renormalization for the resulting Gaussian
mean-field equations, both static and dynamical, are examined and initial
conditions discussed. We also investigate solutions for the gap equation and
show that the energy density has a single minimum.Comment: 21 pages, latex, 4 postscript figures, new sections, some literary
changes, notation corrections, accepted for publication in Phys. Rev
Weighted ergodic theorems for Banach-Kantorovich lattice
In the present paper we prove weighted ergodic theorems and multiparameter
weighted ergodic theorems for positive contractions acting on
. Our main tool is the use of methods of
measurable bundles of Banach-Kantorovich lattices.Comment: 11 page
Stent implantation for a totally occluded right coronary artery in a six-year-old boy after Kawasaki disease: a case report
<p>Abstract</p> <p>Introduction</p> <p>Coronary stenting has previously been considered to be less feasible in children under 12 years old due to the limitation of vascular access. We report the case of a six-year-old boy who successfully underwent stent implantation for his totally occluded right coronary artery.</p> <p>Case presentation</p> <p>A Taiwanese boy aged six years and nine months old was found to have giant aneurysms after an acute episode of Kawasaki disease. An angiography revealed that his middle right coronary artery was totally occluded. A 0.014-inch guidewire was advanced to cross the totally occluded site. After pre-dilating the middle portion of his right coronary artery with a 1.5 mm balloon, stenting of his right coronary artery was accomplished using a 2.5 × 28 mm and a 2.5 × 18 mm bare metal stent. A final angiography demonstrated no residual stenosis or dissection.</p> <p>Conclusion</p> <p>Coronary stenting could be a therapeutic option for children as young as six years old. Close follow-up is mandatory because the long-term outcome is still unclear, especially in a small child.</p
The Minimum Stellar Mass in Early Galaxies
The conditions for the fragmentation of the baryonic component during merging
of dark matter halos in the early Universe are studied. We assume that the
baryonic component undergoes a shock compression. The characteristic masses of
protostellar molecular clouds and the minimum masses of protostars formed in
these clouds decrease with increasing halo mass. This may indicate that the
initial stellar mass function in more massive galaxies was shifted towards
lower masses during the initial stages of their formation. This would result in
an increase of the number of stars per unit halo mass, i.e., the efficiency of
star formation.Comment: 18 pages, 7 figure
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