Volume 115, Issue 14, 08 October 2001
Index of content:
115(2001); http://dx.doi.org/10.1063/1.1409351View Description Hide Description
Collision-induced rotational alignment of NO is measured for rotationally inelastic scattering of NO with Ar at 65 meV collision energy. The experiments are performed by velocity-mapped ion imaging with polarized REMPI probing of the scattered NO products. It is shown that the azimuthal information intrinsic to imaging detection allows the measurement of additional alignment moments not previously reported. The measured alignment shows only qualitative agreement with the predictions of the kinematic apse conservation model.
Pump–probe polarization anisotropy study of doubly degenerate electronic reorientation in silicon naphthalocyanine115(2001); http://dx.doi.org/10.1063/1.1409352View Description Hide Description
Measurements with 26 fs pulses that cover the band of silicon 2,3-naphthalocyanine bis(trihexylsilyloxide) yielded an initial anisotropy of 0.40 that decayed to 0.12 over 200 fs. This contradicts theories predicting anisotropy decay from 7/10 to 1/10. Including ground state bleaching and excited state absorption, anisotropy decay from 2/5 to 1/10 is predicted for degenerate electronic reorientation and dephasing.
115(2001); http://dx.doi.org/10.1063/1.1409957View Description Hide Description
We have calculated generalized longitudinal, shear, and bulk, viscosity of argon at two thermodynamic states by molecular-dynamics simulation. Bulk viscosity has been evaluated with two independent methods that give results in good agreement. We find that bulk viscosity stays positive at all wave numbers k, and show that negative values of are due to a straightforward (and incorrect) extension to finite k’s of the relation only valid at vanishing k’s.