2,314 research outputs found
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Upgrade to the SHARP EUV mask microscope
The Sharp High-NA Actinic Reticle review Project (SHARP) is a synchrotron-based, extreme ultraviolet (EUV) microscope dedicated to photomask research. A potential upgrade to the SHARP microscope is presented. The upgrade includes changing the light path in the instrument from its current off-Axis configuration to an on-Axis configuration. This change allows for an increased working distance of 2.5 mm or more. A central obscuration, added to the zoneplate aperture, blocks stray light from reaching the central part of the image, thus improving the image contrast. The imaging performance of the two configurations is evaluated by means of ray tracing
Phase separation in a boson-fermion mixture of Lithium atoms
We use a semiclassical three-fluid model to analyze the conditions for
spatial phase separation in a mixture of fermionic Li-6 and a (stable)
Bose-Einstein condensate of Li-7 atoms under cylindrical harmonic confinement,
both at zero and finite temperature. We show that with the parameters of the
Paris experiment [F. Schrek et al., Phys. Rev. Lett. 87 080403 (2001)] an
increase of the boson-fermion scattering length by a factor five would be
sufficient to enter the phase-separated regime. We give examples of
configurations for the density profiles in phase separation and estimate that
the transition should persist at temperatures typical of current experiments.
For higher values of the boson-fermion coupling we also find a new phase
separation between the fermions and the bosonic thermal cloud at finite
temperature.Comment: 8 pages, 4 figures, new version of Fig. 4 and typos correcte
Bose-Fermi Mixtures in One Dimension
We analyze the phase stability and the response of a mixture of bosons and
spin-polarized fermions in one dimension (1D). Unlike in 3D, phase separation
happens for low fermion densities. The dynamics of the mixture at low energy is
independent of the spin-statistics of the components, and zero-sound-like modes
exist that are essentially undamped.Comment: 5 pages; 1 figur
The Experimental plan of the 4m Resonant Sideband Extraction Prototype for The LCGT
The 4m Resonant Sideband Extraction (RSE) interferometer is a planned prototype of the LCGT interferometer. The aim of the experiment is to operate a powerrecycled Broadband RSE interferometer with suspended optics and to achieve diagonalization of length signals of the central part of the interferometer directly through the optical setup. Details of the 4m RSE interferometer control method as well as the design of the experimental setup will be presented
M4 muscarinic receptor knockout mice display abnormal social behavior and decreased prepulse inhibition
<p>Abstract</p> <p>Background</p> <p>In the central nervous system (CNS), the muscarinic system plays key roles in learning and memory, as well as in the regulation of many sensory, motor, and autonomic processes, and is thought to be involved in the pathophysiology of several major diseases of the CNS, such as Alzheimer's disease, depression, and schizophrenia. Previous studies reveal that M<sub>4 </sub>muscarinic receptor knockout (M<sub>4</sub>R KO) mice displayed an increase in basal locomotor activity, an increase in sensitivity to the prepulse inhibition (PPI)-disrupting effect of psychotomimetics, and normal basal PPI. However, other behaviorally significant roles of M<sub>4</sub>R remain unclear.</p> <p>Results</p> <p>In this study, to further investigate precise functional roles of M<sub>4</sub>R in the CNS, M<sub>4</sub>R KO mice were subjected to a battery of behavioral tests. M<sub>4</sub>R KO mice showed no significant impairments in nociception, neuromuscular strength, or motor coordination/learning. In open field, light/dark transition, and social interaction tests, consistent with previous studies, M<sub>4</sub>R KO mice displayed enhanced locomotor activity compared to their wild-type littermates. In the open field test, M<sub>4</sub>R KO mice exhibited novelty-induced locomotor hyperactivity. In the social interaction test, contacts between pairs of M<sub>4</sub>R KO mice lasted shorter than those of wild-type mice. In the sensorimotor gating test, M<sub>4</sub>R KO mice showed a decrease in PPI, whereas in the startle response test, in contrast to a previous study, M<sub>4</sub>R KO mice demonstrated normal startle response. M<sub>4</sub>R KO mice also displayed normal performance in the Morris water maze test.</p> <p>Conclusions</p> <p>These findings indicate that M<sub>4</sub>R is involved in regulation of locomotor activity, social behavior, and sensorimotor gating in mice. Together with decreased PPI, abnormal social behavior, which was newly identified in the present study, may represent a behavioral abnormality related to psychiatric disorders including schizophrenia.</p
Phase Coherence in a Driven Double-Well System
We analyze the dynamics of the molecular field incoherently pumped by the
photoassociation of fermionic atoms and coupled by quantum tunnelling in a
double-well potential. The relative phase distribution of the molecular modes
in each well and their phase coherence are shown to build up owing to quantum
mechanical fluctuations starting from the vacuum state. We identify three
qualitatively different steady-state phase distributions, depending on the
ratio of the molecule-molecule interaction strength to interwell tunnelling,
and examine the crossover from a phase-coherent regime to a phase-incoherent
regime as this ratio increases.Comment: 5 pages, 2 figure
Random-phase approximation study of collective excitations in the Bose-Fermi mixed condensate of alkali-metal gases
We perform Random Phase Approximation (RPA) study of collective excitations
in the bose-fermi mixed degenerate gas of Alkali-metal atoms at T=0. The
calculation is done by diagonalization in a model space composed of
particle-hole type excitations from the ground state, the latter being obtained
from the coupled Gross-Pitaevskii and Thomas-Fermi equations. We investigate
strength distributions for different combinations of bose and fermi multipole
() operators with . Transition densities and dynamical structure
factors are calculated for collective excitations. Comparison with the sum rule
prediction for the collective frequency is given. Time dependent behavior of
the system after an external impulse is studied.Comment: 28 pages, 13 figures, submitted to Phys. Rev.
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Evolution of mixing state of black carbon particles: Aircraft measurements over the western Pacific in March 2004
We report the evolution of the mixing state of black carbon (BC) particles in urban plumes measured by an airborne single particle soot photometer. The aircraft observations were conducted over the ocean near the coast of Japan in March 2004. The number fiaction of coated BC particles with a core diameter of 180 mn increased from 0.35 to 0.63 within 12 hours (h), namely 2.3% h-1, after being emitted from the Nagoya urban area in Japan. BC particles with a core diameter of 250 nm increased at the slower rate of 1.0% h-1. The increase in coated BC particles was associated with increases in non-sea salt sulfate and water-soluble organic carbon by a factor of approximately two, indicating that these compounds contributed to the coating on the BC particles. These results give direct evidence that BC particles become internally mixed on a time scale of 12 h in urban plumes. Copyright 2007 by the American Geophysical Union
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