1,917 research outputs found
Priming Effects on Commitment to Help and on Real Helping Behavior
Years of research on bystander apathy have demonstrated that the physical presence of
others can reduce the tendency to help individuals needing assistance. Recent research
on the implicit bystander effect has suggested that simply imagining the presence of
others can lead to less helping behavior on a subsequent unrelated task. The present
study was designed to contribute to previous findings on the implicit bystander effect
by demonstrating these effects on commitment to help and on real helping behavior,
rather than simply on intentions to help. Studies 1a and 1b demonstrate that merely
priming participants with the construct of being in a group at Time 1 created significantly
less commitment to future helping on a subsequent task at Time 2. Study 2 aimed
to extend this effect to behavioral measures and verified that participants exposed to a
group prime helped less than those who were exposed to a single-person prime. The
implications of these findings for the literature on the bystander effect are discussed
Cooling to the Ground State of Axial Motion for One Atom Strongly Coupled to an Optical Cavity
Localization to the ground state of axial motion is demonstrated for a
single, trapped atom strongly coupled to the field of a high finesse optical
resonator. The axial atomic motion is cooled by way of coherent Raman
transitions on the red vibrational sideband. An efficient state detection
scheme enabled by strong coupling in cavity QED is used to record the Raman
spectrum, from which the state of atomic motion is inferred. We find that the
lowest vibrational level of the axial potential with zero-point energy 13uK is
occupied with probability P0~0.95.Comment: 5 pages, 4 figure
Iron(III) Complexes on a Dendrimeric Basis and Various Amine Core Investigated by Mössbauer Spectroscopy
Dendrimers of various generations were synthesized by the divergent method. Starting from various amine cores (G(0a), G(0b), G(0c)) the generations were built by reaction of the amine with acrylnitrile followed by hydrogenation with DIBAL-H. Treatment with salicylaldehyde creates a fivefold coordination sphere for iron in the molecular periphery. The resulting multinuclear coordination compounds are investigated by Mossbauer spectroscopy
Recent Results on the Periodic Lorentz Gas
The Drude-Lorentz model for the motion of electrons in a solid is a classical
model in statistical mechanics, where electrons are represented as point
particles bouncing on a fixed system of obstacles (the atoms in the solid).
Under some appropriate scaling assumption -- known as the Boltzmann-Grad
scaling by analogy with the kinetic theory of rarefied gases -- this system can
be described in some limit by a linear Boltzmann equation, assuming that the
configuration of obstacles is random [G. Gallavotti, [Phys. Rev. (2) vol. 185
(1969), 308]). The case of a periodic configuration of obstacles (like atoms in
a crystal) leads to a completely different limiting dynamics. These lecture
notes review several results on this problem obtained in the past decade as
joint work with J. Bourgain, E. Caglioti and B. Wennberg.Comment: 62 pages. Course at the conference "Topics in PDEs and applications
2008" held in Granada, April 7-11 2008; figure 13 and a misprint in Theorem
4.6 corrected in the new versio
Linear and nonlinear optical spectroscopy of a strongly-coupled microdisk-quantum dot system
A fiber taper waveguide is used to perform direct optical spectroscopy of a
microdisk-quantum-dot system, exciting the system through the photonic (light)
channel rather than the excitonic (matter) channel. Strong coupling, the regime
of coherent quantum interactions, is demonstrated through observation of vacuum
Rabi splitting in the transmitted and reflected signals from the cavity. The
fiber coupling method also allows the examination of the system's steady-state
nonlinear properties, where saturation of the cavity-QD response is observed
for less than one intracavity photon.Comment: adjusted references, added minor clarification
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