Non-Lorentzian line shapes for interfering rotational resonances in the predissociation of O(2)

Rotationally resolved measurements are presented of interacting predissociating resonances in the Schumann-Runge bands of O₂that exhibit destructive quantum interference for energies between the line centers. The interacting resonances are described using a coupled line shape derived by treating simultaneously the perturbation and predissociation processes using the method of Fano.B. R. Lewis, P. M. Dooley, J. P. England, S. T. Gibson, and K. G. H. Baldwin, L. W. Toro

Asymmetry sum rule for molecular predissociation

© 2000 American Physical SocietyIn the case of weak diatomic molecular predissociation by noninteracting, optically inactive continuum states, it is demonstrated that the predissociation line shape is more accurately represented by a Beutler-Fano profile than by a Lorentzian. The weak asymmetry that is found to occur is due principally to interactions with neighboring vibrational resonances. For this type of predissociation in the case of multiple continua, a sum rule for the corresponding line-shape asymmetry is derived. This sum rule is verified numerically using single-channel and multichannel coupled Schrödinger-equation calculations for the Schumann-Runge band system of O2. Similar results are presented for the case of optically active continua.F. T. Hawes, L. W. Torop, B. R. Lewis and S. T. Gibso

Morphing in nature and beyond: a review of natural and synthetic shape-changing materials and mechanisms

Shape-changing materials open an entirely new solution space for a wide range of disciplines: from architecture that responds to the environment and medical devices that unpack inside the body, to passive sensors and novel robotic actuators. While synthetic shape-changing materials are still in their infancy, studies of biological morphing materials have revealed key paradigms and features which underlie efficient natural shape-change. Here, we review some of these insights and how they have been, or may be, translated to artificial solutions. We focus on soft matter due to its prevalence in nature, compatibility with users and potential for novel design. Initially, we review examples of natural shape-changing materials—skeletal muscle, tendons and plant tissues—and compare with synthetic examples with similar methods of operation. Stimuli to motion are outlined in general principle, with examples of their use and potential in manufactured systems. Anisotropy is identified as a crucial element in directing shape-change to fulfil designed tasks, and some manufacturing routes to its achievement are highlighted. We conclude with potential directions for future work, including the simultaneous development of materials and manufacturing techniques and the hierarchical combination of effects at multiple length scales.</p

The NaI A0+ state potential curve: some criteria and their implications

Information about the NaI A0+ potential curve is assessed, leading to a statement of the best current information on that potential. By critically examining the literature on that potential, by modelling our photoabsorption measurements, and by using our and other ab initio calculations we obtain criteria that the potential must meet. Although the criteria do not specify the potential, they are sufficient to show that several published suggestions for the potential must be rejected and that one is acceptable. The criteria do strongly restrict the potential and we use them to obtain a not very complicated reasonable analytic form that satisfies all the criteria. © 2001 Elsevier Science B.V

An investigation of the photodissociation of molecular oxygen in the 75 to 85 nm region.

Jones, A.L.; Blake, A.J.; Torop, L.; McCoy, D.G