"Analysis lends itself very nicely to the fluorescent excitation because you come in with very long wavelength radiation, which is less damaging, and then get the two-photon effect at the short wavelength excitation energy
just at the point of excitation of the cells."
All the normal modes (15a) and (15b) and the excitation energy
branches (16a)-(16c) are symmetric with respect to the permutation of the vectors [M.sub.1] and [M.sub.2].
For this reason, we matched the effective central photon energy of the laser pulse to the relevant density-functional (rather than experimental) excitation energy
and this should not affect the interpretation of the results.
However these results do not rule out the overall hypothesis which we consider: there is a possibility that nuclear synthesis involving o-Ps is cut off in the stage of formation of the "compound ion" [[sup.4*]He [e.sup.-].sup.+], with subsequent relaxation of nuclear excitation energy
(23.85 MeV) as kinetic energy of an "[alpha]-particle", as the "long-range atom" through an "atomic nucleus" can relinquish its non-recoil energy.
(The L[alpha] line offers the advantage of higher spatial resolution obtainable with the low accelerating voltage permitted by the lower excitation energy
, but is inappropriate for quantitative analysis for Z < 30, owing to uncertainties in the absorption correction.)
In this paper, we investigated the role of excitation energy
on the Raman intensity of these modes by choosing two laser energies, the green laser (514.5 nm = 2.41 eV) having energy larger than the bandgap energy of all the [In.sub.1-x][Ga.sub.x]N films we have studied here and the red laser (785 nm = 1.58 eV) having energy between the band gap energy of x = 0.3 film ([E.sub.g] = 1.30 eV) and of x = 0.54 film ([E.sub.g] = 1.85 eV).
Structure [E.sub.tot], (a.u.) [DELTA]E, (kcal/mol) (2b) -1794.994270 0 (2b)TTC-SP -1794.985809 5.3 (2b)TTC-TTC -1794.988572 3.6 Table 4: Excitation energy
[E.sub.ex] (eV), corrected  excitation energy
[E.sub.corr] (eV) and oscillator strength f of the first three singlet transitions of the merocyanine (2a)TTC-SP and (2a)TTC-TTC according to the TD DFT CPCM/PBE0/6-311G** calculation in toluene solution.
where [E.sub.0] is the incident beam energy (keV), [E.sub.c] is the critical excitation energy
for the characteristic x rays of interest (keV), A is the atomic weight (g/mol), Z is the atomic number, and [rho] is the density (g/[cm.sup.3]).
For particular tubular structures, besides the band structure and corresponding gap, excitation energy
and energy of folding (stretch energy) are also calculated.