431 research outputs found
Weekly report for R.V. Polarstern expedition ANT-XXII/4, report no. 6 (21.05.2005), german version
Weekly report for R.V. Polarstern expedition ANT-XXII/4, report no. 5 (14.5.2005), german version
Nonadiabatic creation of macroscopic superpositions with strongly correlated 1D bosons on a ring trap
We consider a strongly interacting quasi-one dimensional Bose gas on a tight
ring trap subjected to a localized barrier potential. We explore the
possibility to form a macroscopic superposition of a rotating and a nonrotating
state under nonequilibrium conditions, achieved by a sudden quench of the
barrier velocity. Using an exact solution for the dynamical evolution in the
impenetrable-boson (Tonks-Girardeau) limit, we find an expression for the
many-body wavefunction corresponding to a superposition state. The
superposition is formed when the barrier velocity is tuned close to multiples
of integer or half-integer number of Coriolis flux quanta. As a consequence of
the strong interactions, we find that (i) the state of the system can be mapped
onto a macroscopic superposition of two Fermi spheres, rather than two
macroscopically occupied single-particle states as in a weakly interacting gas,
and (ii) the barrier velocity should be larger than the sound velocity to
better discriminate the two components of the superposition.Comment: 5 pages, 3 figures, revised introduction and new Fig3, final version
to appear in PR
The Bender Visual-Motor Gestalt Test as a Measure of Aggression in Children
The Bender-Gestalt Test has been routinely used for the past two years at the Annie Wittenmyer Home, an institution for dependent and neglected children in Iowa. This simple test was first designed by Bender (1938), as a performance test for young children. Her manual also indicates that the test can be used in the differentiation of organic brain anomolies, schizophrenias and psychoneuroses. This area of research has been covered by Hutt (1945) Swenson and Pascal (1953), Guertin (1954), and others. The observations of the writers have indicated that there is a wide difference in the way apparently normal children respond to these designs. These differences have heretofore been interpreted in the light of Hutt\u27s (1945) findings with an adult population. For example, he indicated that such things as diminution of the figures, conservation of space and the use of light pressure in drawing are indicative of social withdrawal, limited activity and unassertiveness. In another article Hutt (1953) stated that, aggressive and rebellious individuals usually show an excessive use of space. On the other hand an inordinately small amount of space between successive drawings is indicative of repressed hostility, occasionally turned inwards in the form of masochistic strivings or needs. Peek (1953) has shown that the direction of drawing a single line such as the diagonal on the figure 5 (an incomplete circle with an intersecting slanting line both composed of dots) can be indicative of differences in personality adjustment. He found that patients drawing the diagonal toward the half-circle rather than in the popular direction, i.e., away from the halfcircle were significantly more immature and dependent than the control group. Rather than being able to direct their hostility upon the sources of their frustration they were inclined to use less adaptive mechanisms such as headaches and other somatic complaints. They were therefore more apt to build up frustrations which spill over into poorly controlled and indirect forms of aggressive hostility
Boundary crossing in R&D projects in schools: learning through cross-professional collaboration
Schools as professional learning communities: what can schools do to support professional development of their teachers?
Boundary crossing in R&D projects in schools: learning through cross-professional collaboration
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