33,883 research outputs found
Engineering direct-indirect band gap transition in wurtzite GaAs nanowires through size and uniaxial strain
Electronic structures of wurtzite GaAs nanowires in the [0001] direction were
studied using first-principles calculations. It was found that the band gap of
GaAs nanowires experience a direct-to-indirect transition when the diameter of
the nanowires is smaller than ~28 {\AA}. For those thin GaAs nanowires with an
indirect band gap, it was found that the gap can be tuned to be direct if a
moderate external uniaxial strain is applied. Both tensile and compressive
strain can trigger the indirect-to-direct gap transition. The critical strains
for the gap-transition are determined by the energy crossover of two states in
conduction bands.Comment: 4 pages, 4 figure
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A Palette of Deepened Emotions: Exploring Emotional Challenge in Virtual Reality Games
Recent work introduced the notion of ‘emotional challenge’promising for understanding more unique and diverse player experiences (PX). Although emotional challenge has immediately attracted HCI researchers’ attention, the concept has not been experimentally explored, especially in virtual reality (VR), one of the latest gaming environments. We conducted two experiments to investigate how emotional challenge affects PX when separately from or jointly with conventional challenge in VR and PC conditions. We found that relatively exclusive emotional challenge induced a wider range of different emotions in both conditions, while the adding of emotional challenge broadened emotional responses only in VR. In both experiments, VR significantly enhanced the measured PX of emotional responses, appreciation, immersion and presence. Our findings indicate that VR may be an ideal medium to present emotional challenge and also extend the understanding of emotional (and conventional) challenge in video games
In-medium Properties of as a KN structure in Relativistic Mean Field Theory
The properties of nuclear matter are discussed with the relativistic
mean-field theory (RMF).Then, we use two models in studying the in-medium
properties of : one is the point-like in the usual RMF and
the other is a KN structure for the pentaquark. It is found that the
in-medium properties of are dramatically modified by its internal
structure. The effective mass of in medium is, at normal nuclear
density, about 1030 MeV in the point-like model, while it is about 1120 MeV in
the model of KN pentaquark. The nuclear potential depth of in
the KN model is approximately -37.5 MeV, much shallower than -90 MeV in
the usual point-like RMF model.Comment: 8 pages, 5 figure
The properties of kaonic nuclei in relativistic mean-field theory
The static properties of some possible light and moderate kaonic nuclei, from
C to Ti, are studied in the relativistic mean-field theory. The 1s and 1p state
binding energies of are in the range of MeV and
MeV, respectively. The binding energies of 1p states increase monotonically
with the nucleon number A. The upper limit of the widths are about
MeV for the 1s states, and about MeV for the 1p states. The lower
limit of the widths are about MeV for the 1s states, and
MeV for the 1p states. If MeV, the discrete bound states
should be identified in experiment. The shrinkage effect is found in the
possible kaonic nuclei. The interior nuclear density increases obviously, the
densest center density is about .Comment: 9 pages, 2 tables and 1 figure, widths are considered, changes a lo
A discussion of the scaling effect in numerical simulation of the extrusion process
The main objective of the work of this paper is to study the possibility of using a small scale geometrical model in the numerical simulation of aluminium extrusion. The advantages and shortcomings of the application of the
geometrically similar model in FEM simulation are discussed. Thermal – mechanical and metallurgical combined
simulations are performed within two tests using geometrically similar models and assessment is made in terms of mechanical and material properties. It was found that small scale simulation could not reproduce most of the
important forming parameters of the original process, although it could help to bring about significant savings in
computation time
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