Two-dimensional resonance enhanced multiphoton ionization of H(i)Cl; i = 35, 37: state interactions, photofragmentations and energetics of high energy Rydberg states

Mass spectra were recorded for (2 + n) resonance enhanced multiphoton ionization (REMPI) of HCl as a function of resonance excitation energy in the 88865-89285 cm(-1) region to obtain two-dimensional REMPI data. Band spectra due to two-photon resonance transitions to number of Rydberg states (Ω' = 0, 1, and 2) and the ion-pair state V((1)Σ(+)(Ω' = 0)) for H(35)Cl and H(37)Cl were identified, assigned, and analyzed with respect to Rydberg to ion-pair interactions. Perturbations show as line-, hence energy level-, shifts, as well as ion signal intensity variations with rotational quantum numbers, J', which, together, allowed determination of parameters relevant to the nature and strength of the state interactions as well as dissociation and ionization processes. Whereas near-resonance, level-to-level, interactions are found to be dominant in heterogeneous state interactions (ΔΩ ≠ 0) significant off-resonance interactions are observed in homogeneous interactions (ΔΩ = 0). The alterations in Cl(+) and HCl(+) signal intensities prove to be very useful for spectra assignments. Data relevant to excitations to the j(3)Σ(0(+)) Rydberg states and comparison with (3 + n) REMPI spectra allowed reassignment of corresponding spectra peaks. A band previously assigned to an Ω = 0 Rydberg state was reassigned to an Ω = 2 state (ν(0) = 88957.6 cm(-1)).     

Evolutive and nonlinear vibrations of rotor on aerodynamic bearings

The use of air as a lubricant in aerodynamic bearings is advantageous, particularly in the food industry. Aerodynamic bearings with tilting pads have complicated stiffness and damping properties and need a very detailed theoretical and experimental research. Response curves of rigid rotor supported on aerodynamic bearings are presented for a linear but evolutive mathematical model. Due to non-monotone properties of stiffness and damping matrices at variable revolutions, a new resonance appears. The mathematical model of rotor vibrations in the whole area of bearing clearance is also developed in the consideration of strongly nonlinear properties of aerodynamic bearing.     

A simple expression for the microwave surface impedance in the ferromagnetic antiresonance region

There is derived a simple analytical expression for the real component of the microwave surface impedance in the ferromagnetic antiresonance region at the external field parallel to the ferromagnetic metal sample surface. The formula for the field derivative of the surface impedance (the quantity usually measured in the experiment) is evaluated. Some properties of this expression are investigated and there are analyzed two definitions of the ferromagnetic antiresonance curve width which are suitable for the Landau-Lifshitz relaxation parameter determination from the experiment.