22,858 research outputs found
Regulatory Focus and Interdependent Economic Decision-Making
Traditional theories of self-interest cannot predict when individuals pursue relative and absolute economic outcomes in interdependent decision-making, but we argue that regulatory focus (Higgins, 1997) can. We propose that a concern with security (prevention focus) motivates concerns with social status, leading to the regulation of relative economic outcomes, but a concern with growth (promotion focus) motivates the maximization of opportunities, leading to a focus on absolute outcomes. Two studies supported our predictions; regardless of prosocial or proself motivations, a promotion focus yielded greater concern with absolute outcomes, but a prevention focus yielded greater concern with relative outcomes. Also, Study 3 revealed that a prevention focus led to a greater rejection of a negative relative but positive absolute outcome in an ultimatum game because of concerns with status. This research reveals that apparently opposing orientations to interdependence – equality and relative gain – serve the same self-regulatory purpose: the establishment of security
Spectral Representation Theory for Dielectric Behavior of Nonspherical Cell Suspensions
Recent experiments revealed that the dielectric dispersion spectrum of
fission yeast cells in a suspension was mainly composed of two sub-dispersions.
The low-frequency sub-dispersion depended on the cell length, while the
high-frequency one was independent of it. The cell shape effect was simulated
by an ellipsoidal cell model but the comparison between theory and experiment
was far from being satisfactory. Prompted by the discrepancy, we proposed the
use of spectral representation to analyze more realistic cell models. We
adopted a shell-spheroidal model to analyze the effects of the cell membrane.
It is found that the dielectric property of the cell membrane has only a minor
effect on the dispersion magnitude ratio and the characteristic frequency
ratio. We further included the effect of rotation of dipole induced by an
external electric field, and solved the dipole-rotation spheroidal model in the
spectral representation. Good agreement between theory and experiment has been
obtained.Comment: 19 pages, 5 eps figure
Comparison of Magnetic Flux Distribution between a Coronal Hole and a Quiet Region
Employing Big Bear Solar Observatory (BBSO) deep magnetograms and H
images in a quiet region and a coronal hole, observed on September 14 and 16,
2004, respectively, we have explored the magnetic flux emergence, disappearance
and distribution in the two regions. The following results are obtained: (1)
The evolution of magnetic flux in the quiet region is much faster than that in
the coronal hole, as the flux appeared in the form of ephemeral regions in the
quiet region is 4.3 times as large as that in the coronal hole, and the flux
disappeared in the form of flux cancellation, 2.9 times as fast as in the
coronal hole. (2) More magnetic elements with opposite polarities in the quiet
region are connected by arch filaments, estimating from magnetograms and
H images. (3) We measured the magnetic flux of about 1000 magnetic
elements in each observing region. The flux distribution of network and
intranetwork (IN) elements is similar in both polarities in the quiet region.
For network fields in the coronal hole, the number of negative elements is much
more than that of positive elements. However for the IN fields, the number of
positive elements is much more than that of negative elements. (4) In the
coronal hole, the fraction of negative flux change obviously with different
threshold flux density. 73% of the magnetic fields with flux density larger
than 2 Gauss is negative polarity, and 95% of the magnetic fields is negative,
if we only measure the fields with their flux density larger than 20 Gauss. Our
results display that in a coronal hole, stronger fields is occupied by one
predominant polarity; however the majority of weaker fields, occupied by the
other polarity
The dynamics of loop formation in a semiflexible polymer
The dynamics of loop formation by linear polymer chains has been a topic of
several theoretical/experimental studies. Formation of loops and their opening
are key processes in many important biological processes. Loop formation in
flexible chains has been extensively studied by many groups. However, in the
more realistic case of semiflexible polymers, not much results are available.
In a recent study (K. P. Santo and K. L. Sebastian, Phys. Rev. E, \textbf{73},
031293 (2006)), we investigated opening dynamics of semiflexible loops in the
short chain limit and presented results for opening rates as a function of the
length of the chain. We presented an approximate model for a semiflexible
polymer in the rod limit, based on a semiclassical expansion of the bending
energy of the chain. The model provided an easy way to describe the dynamics.
In this paper, using this model, we investigate the reverse process, i.e., the
loop formation dynamics of a semiflexible polymer chain by describing the
process as a diffusion-controlled reaction. We perform a detailed
multidimensional analysis of the problem and calculate closing times for a
semiflexible chain which leads to results that are physically expected. Such a
multidimensional analysis leading to these results does not seem to exist in
the literature so far.Comment: 37 pages 4 figure
20 K superconductivity in heavily electron doped surface layer of FeSe bulk crystal
A superconducting transition temperature Tc as high as 100 K was recently
discovered in 1 monolayer (1ML) FeSe grown on SrTiO3 (STO). The discovery
immediately ignited efforts to identify the mechanism for the dramatically
enhanced Tc from its bulk value of 7 K. Currently, there are two main views on
the origin of the enhanced Tc; in the first view, the enhancement comes from an
interfacial effect while in the other it is from excess electrons with strong
correlation strength. The issue is controversial and there are evidences that
support each view. Finding the origin of the Tc enhancement could be the key to
achieving even higher Tc and to identifying the microscopic mechanism for the
superconductivity in iron-based materials. Here, we report the observation of
20 K superconductivity in the electron doped surface layer of FeSe. The
electronic state of the surface layer possesses all the key spectroscopic
aspects of the 1ML FeSe on STO. Without any interface effect, the surface layer
state is found to have a moderate Tc of 20 K with a smaller gap opening of 4
meV. Our results clearly show that excess electrons with strong correlation
strength alone cannot induce the maximum Tc, which in turn strongly suggests
need for an interfacial effect to reach the enhanced Tc found in 1ML FeSe/STO.Comment: 5 pages, 4 figure
The double charm decays of B Mesons in the mSUGRA model
Based on the low energy effective Hamiltonian with naive factorization, we
calculate the branching ratios(BRs) and CP asymmetries (CPAs) for the twenty
three double charm decays in both the
standard model (SM) and the minimal supergravity (mSUGRA) model. Within the
considered parameter space, we find that (a) the theoretical predictions for
the BRs, CPAs and the polarization fractions in the SM and the mSUGRA model are
all consistent with the currently available data within errors;
(b) For all the considered decays, the supersymmetric contributions in the
mSUGRA model are very small, less than numerically. It may be difficult
to observe so small SUSY contributions even at LHC.Comment: 15 pages, 5tables, no figure
Dipole-Allowed Direct Band Gap Silicon Superlattices
Silicon is the most popular material used in electronic devices. However, its
poor optical properties owing to its indirect band gap nature limit its usage
in optoelectronic devices. Here we present the discovery of super-stable
pure-silicon superlattice structures that can serve as promising materials for
solar cell applications and can lead to the realization of pure Si-based
optoelectronic devices. The structures are almost identical to that of bulk Si
except that defective layers are intercalated in the diamond lattice. The
superlattices exhibit dipole-allowed direct band gaps as well as indirect band
gaps, providing ideal conditions for the investigation of a direct-to-indirect
band gap transition. The transition can be understood in terms of a novel
conduction band originating from defective layers, an overlap between the
valence- and conduction-band edge states at the interface layers, and zone
folding with quantum confinement effects on the conduction band of
non-defective bulk-like Si. The fact that almost all structural portions of the
superlattices originate from bulk Si warrants their stability and good lattice
matching with bulk Si. Through first-principles molecular dynamics simulations,
we confirmed their thermal stability and propose a possible method to
synthesize the defective layer through wafer bonding
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