We performed experiments with electrons in a Malmberg-Penning trap, as well as 2D fluid simulations, and found conditions that lead to off-axis equilibrium states. We found that unstable initial distributions whose average distance from the axis is larger than about half the wall radius end up in off-axis states. These states consist of a small strong vortex and a large diffuse background, each...

The title compound, UCu(0.60(4))Sb(2), crystallizes in the tetragonal space group P4/nmm. The U atom and one independent Sb atom have 4mm site symmetry, whereas the Cu atom and the other Sb atom have \overline{4}2m site symmetry. Zigzag USb sheets stack perpendicular to the c axis. These sheets are separated by square-planar nets of Sb atoms and Cu atoms. The length of the a axis for UCu(x)Sb(2...

Bilateral symmetry is an extremely salient feature for the human visual system. An interesting issue is whether the perceptual salience of symmetry is rooted in normal visual development. In this review, we discuss empirical work on visual and tactile symmetry detection in normally sighted and visually impaired individuals. On the one hand, available evidence suggests that efficient visual symm...

In the title hydrated salt, C(15)H(11)Br(2)N(2) (+)·Cl(-)·2H(2)O, the complete imidazolium cation is generated by a crystallographic twofold axis, with one C atom lying on the axis. The chloride ion and both water mol-ecules of crystallization also lie on a crystallographic twofold axis of symmetry. The cation is non-planar, the dihedral angle formed between the central imidazolium and benzene ...

An analysis of previous studies of bilateral symmetry detection in dot patterns revealed what appeared to be an almost arbitrary choice of pattern parameters and constraints with no systemic examination of the effects of these parameters and constraints on observer performance. In Expt 1, 100-dot patterns either had no constraints on how they were plotted or had one or both of two constraints: ...

A large number of viral capsids, as well as other macromolecular assemblies, have icosahedral structure or structures with other rotational symmetries. This symmetry can be exploited during molecular dynamics (MD) to model in effect the full viral capsid using only a subset of primary atoms plus copies of image atoms generated from rotational symmetry boundary conditions (RSBC). A pure rotation...

We describe a simple and novel approach to identify main similarity axes by maximizing self-similarity of object contour parts divided by the axes. For a symmetric or approximately symmetric shape, the main self-similarity axis coincides with the main axis of symmetry. However, the concept of the main self-similarity axis is more general, and significantly easier to compute. By identifying crit...

The title compound, C(2)H(2)·C(12)H(24)O(6)·2NH(3), was formed by co-crystallization of 18-crown-6 and acetyl-ene in liquid ammonia. The 18-crown-6 mol-ecule has threefold rotoinversion symmetry. The acteylene mol-ecule lies on the threefold axis and the whole mol-ecule is generated by an inversion center. The two ammonia mol-ecules are also located on the threefold axis and are related by inve...

Humans are very sensitive to symmetry in visual patterns. Symmetry is detected and recognized very rapidly, and eye fixations are concentrated along the axis of symmetry or the symmetrical center of the patterns. This suggests that symmetry is a highly salient feature. Existing computational models of saliency, however, have mainly focused on contrast as a measure of saliency. These models do n...

The complete molecule of the title compound, C(5)H(6)O(4)S(3), is generated by crystallographic twofold symmetry with the C=S group lying on the rotation axis. The molecules are linked through weak hydrogen-bond contacts by glide-plane operations to form R(2) (2)(20) rings and ladder-like C(4) chains along the c axis.