Rotational excitation of H2O, HDO and D2O by thermal electron impact is studied using the molecular R-matrix method. Rate coefficients are obtained up to electron temperatures of 8000 K. De-excitation rates and critical electron densities are also given. It is shown that the dominant transitions are those for which J = 0, ±1, as predicted by the dipolar Born approximation. However, a pure Born ...

We calculate the maximal Lyapunov exponent, the generalized entropies, the asymptotic distance between nearby trajectories and the fractal dimensions for a finite two dimensional system at different initial excitation energies. We show that these quantities have a maximum at about the same excitation energy. The presence of this maximum indicates the transition from a chaotic regime to a more r...

We discuss the dynamics of ultrashort pulsed laser excitation in bulk optical silica-based glasses (fused silica and borosilicate BK7) well-above the permanent modification threshold. We indicate subsequent structural and thermomechanical energy relaxation paths that translate into positive and negative refractive index changes, compression and rarefaction zones. If fast electronic decay occurs...

Conclusions The present study has investigated the problem of the elastic response of a generic space vehicle with degraded joints. The steppedbeam formulation based on elementary beam theory is employed for extracting modal parameters of a normalized generic space vehicle. Next, the modal superposition principle is used with a low damping value for obtaining the elastic response of the vehicle...

Straight elastically supported beams of variable width under the action of a periodic axial force are considered. Two shape optimization problems for reducing parametric resonance zones are studied. In the first problem, the range of resonant frequencies is minimized for a given parametric resonance zone and a fixed amplitude of excitation. In the second problem, the minimal (critical) amplitud...

The use of synchrotron radiation (SR) as an excitation source for total reflection X-ray fluorescence analysis (TXRF) offers several advantages over X-ray tube excitation. Detection limits in the fg range can be achieved with efficient excitation for low Z as well as high Z elements due to the features of synchrotron radiation and in particular the high brilliance in a wide spectral range and t...

Local recurrent networks in neocortex are critical nodes for sensory processing, but their regulation by experience is much less understood than for long-distance (translaminar or cross-columnar) projections. We studied local L2/3 recurrent networks in rat somatosensory cortex during deprivation-induced whisker map plasticity, by expressing channelrhodopsin-2 (ChR2) in L2/3 pyramidal cells and ...

Binaural integration in the central nucleus of inferior colliculus (ICC) plays a critical role in sound localization. However, its arithmetic nature and underlying synaptic mechanisms remain unclear. Here, we showed in mouse ICC neurons that the contralateral dominance is created by a "push-pull"-like mechanism, with contralaterally dominant excitation and more bilaterally balanced inhibition. ...

The generation of coherent and indistinguishable single photons is a critical step for photonic quantum technologies in information processing and metrology. A promising system is the resonant optical excitation of solid-state emitters embedded in wavelength-scale three-dimensional cavities. However, the challenge here is to reject the unwanted excitation to a level below the quantum signal. We...