The handedness of nanometrical helices based on surfactant assemblies was inverted when these helices were in contact with an excess solution of chiral anions with opposite enantiomers. An important difference in the kinetics of chirality inversion at the molecular level and mesoscopic level was observed.

We introduce the notion of semigroup with a tight ideal series and investigate their closures in semitopological semigroups, particularly inverse semigroups with continuous inversion. As a corollary we show that the symmetric inverse semigroup of finite transformations I n λ of the rank 6 n is algebraically closed in the class of (semi)topological inverse semigroups with continuous inversion. W...

In the title compound, C22H24O3S, the cyclo-hexyl ring adopts a chair conformation. The dihedral angle between the mean plane [r.m.s. deviation = 0.010 (1) Å] of the benzo-furan ring system and the benzene ring is 81.78 (4)°. In the crystal, mol-ecules are linked via pairs of C-H⋯π inter-actions into inversion dimers. These dimers are further linked by C-H⋯π inter-actions into supra-molecular c...

Rates of pyramidal motion in an aziridine are controlled by reversible trans to cis photoisomerisation of an azobenzene unit attached to the ring nitrogen atom. The dynamics of the inversion process and activation parameters are derived by variable temperature NMR, and are supported by ab initio calculations.

We model one strand of DNA by a one-dimensional lattice (ODL) of negative charges and consider the problem of inversion of its charge by a positive polyelectrolyte (PE). In the neutral state of the ODL-PE complex, each of the ODL charges is locally compensated by a PE charge. When an additional PE molecule is adsorbed by ODL, its charge gets fractionalized into monomer charges of defects (tails...

Koen BESTEMAN natuurkunding ingenieur geboren te Den Haag.

In two experiments, participants searched for a difference between two views of a scene. In Experiment 1, the authors extended the change-blindness findings from previous work by R. A. Rensink, J. K. O'Regan, and J. J. Clark (1997), which used an experimenter-induced global transient, to a less artificial situation in which participants searched for a difference in a pair of photographic images...

A method is proposed to construct spiral curves by inversion of a spiral arc of parabola. The resulting curve is rational of 4-th order. Proper selection of the parabolic arc and parameters of inversion allows to match a wide range of boundary conditions, namely, tangents and curvatures at the endpoints, including those, assuming inflection.

The number of inversions in a random permutation is a way to measure the extent to which the permutation is “out of order”. Let In(k) denote the number of permutations of length n with k inversions. This paper gives asymptotic formulae for the sequences {In+k(n), n = 1, 2, . . .} for fixed k.