J levels

Figure 9.24 shows part of the laser Stark spectrum of the bent triatomic molecule FNO obtained with a CO infrared laser operating at 1837.430 cm All the transitions shown are Stark components of the rotational line of the Ig vibrational transition, where Vj is the N-F stretching vibration. The rotational symbolism is that for a symmetric rotor (to which FNO approximates) for which q implies that AA = 0, P implies that A/ = — 1 and the numbers indicate that K" = 7 and J" = 8 (see Section 6.2.4.2). In an electric field each J level is split into (J + 1) components (see Section 5.2.3), each specified by its value of Mj. The selection mle when the radiation is polarized perpendicular to the field (as here) is AMj = 1. Eight of the resulting Stark components are shown. 

Third, there are clear differences in the images for dissociation at the same wavelength while probing different spin-orbit states. Two effects contribute to these differences. One is the slight difference in energy in the atomic states, most easily seen in the data at 234 nm where the 0(3P2) data clearly has the strong contribution from vibrationally-excited O2 while the other spin-orbit states do not. In this case the threshold for the dynamical process that forms the vibrationally-excited products has been crossed by the 158.265 cm-1 of the spin-orbit excitation. The second effect is that due to the nature of the J-level. It is known that there is a v—J correlation from the angular fits as well as from the fact that when the polarization of the... 

The rotational spectrum of a molecule involves transitions between energy levels, say the R(8) transition / = 8 and J = 9, but if there are no molecules rotating in the J = 8 level then there can be no R(8) transition. The local thermal collisions will populate some of the higher J levels in a general principle called equipartition. The general expression is the Boltzmann Law, given by ... 

FIG. 2. Mechanism of phenylephrine (PE)-mediated wave-like [Ca2+] oscillations in the rabbit inferior vena cava. (A) PE-mediated [Ca2+]j oscillations are completely inhibited by 10 fiM cyclopiazonic acid (CPA), but the average [Ca2+ ]j remains elevated. (B) PE-mediated [Ca2+]j oscillations are abolished by 75 /iM 2-aminoethoxydiphenyl borate (2-APB). (C) Application of 10 piM nifedipine (Nif) reduced the frequency of PE-mediated [Ca2+]j oscillations while additional application of SKF96365 (SKF) completely abolished the remaining [Ca2+] oscillations. (D) Application of 100 /iM 2,4-dichlorobenzamil (2,4-DCB) completely inhibited nifedipine-resistant PE-induced [Ca2+]j oscillations and lowered the [Ca2+]j to a level that is slightly higher than baseline. Additional application of SKF96365 returned the [Ca2+]j level to baseline. (Experimental traces reproduced with permission from Lee et al 2001.)... 

Minimal risk J level for effects Vi/ other than cancer... 

With this procedure, as with the double-resonance methods in atomic physics, Zeeman and Stark splittings, hyperfine structures and A doublings in molecules can be measured with high precision, even if the observed level splittings are far less than the optical dopp-ler width. From the width of the rf resonance and from the time response of the pumped systems, orientation relaxation rates can be evaluated for individual v J") levels. Other possible applications of this promising technique have been outlined by Zare 30) Experiments to test some of these proposals are currently under investigation and their results will be reported elsewhere. 

The inclusion of the crystal field destroys the rotational symmetry of the ion and lifts the degeneracy of J levels (except of course Kramer s degeneracy) the only good quantum numbers will be T s, the irreducible representations of the point-group symmetry operation. If the crystal field interaction is comparable to J-J splitting (and we see from Table 2 that this is the case of actinides) it will also cause an admixture of different J multiplets. 

It is to be emphasized that such transitions involve the full set of coupled on-site /-electrons. The residual set is left above with the whole series of excited J levels, 5/2 to 15/2, spread over 3/4 eV. The lowest J level probably lies 1/2 eV below the above quoted averaged peak values. The present task is to make some representation of these/ d optical transitions on a one-electron basis. This requires consideration of the response in on-site potential under transference of one electron into a t2g wavefunction. 

FBPase-2). (b) Both enzymes are part of the same polypeptide chain, and both are regulated, in a reciprocal fashion, by insulin and glucagon. Here and elsewhere, arrows are used to indicate increasing (f) and decreasing (J,) levels of metabolites. 

Not knowing otherwise, we make the a priori assumption that any set of populations Nj (that is consistent with the two constraints above) is possible, and must be considered. Assume that the probability of finding the system with a certain set of j-level populations Nj is proportional to W ( Nj ) of Eq. 8.28, which is the total number of ways of arranging the N molecules into that set Ay of populations (consistent with the constraints). 

For C22H2, the nuclear spin of C12 is zero and contributes a factor of 1 to the nuclear statistical weights. The statistical weights are therefore the same as in H2. For the ground vibronic state, the even J levels are s and have nuclear statistical weight 1, corresponding to the one possible ns the odd J levels are a and have nuclear statistical weight 3. The usual selection rule (4.138) holds for collisions as well as radiative transitions, and we have ortho and para acetylene. The two forms have not been separated. 

M. Herman Prof. Troe explicitly referred to the Stark effect in his talk. In the strong-field limit, the Stark effect will mix the j levels. Does his model explicitly take that mixing into account ... 

In solution rare earths also show very sharp spectral transitions similar to those in the crystalline state. These transitions are again to be identified with the excitation of the electrons from the ground level to the excited J levels of the 4fn configuration. 

The quantity g(J)/g(LS) stands for the relative statistical weight of the J level in the LS term. Therefore, formulas (24.12) and (24.13) show that the sum of relative line strengths of the multiplet with given initial or final level is equal to the relative statistical weight of this level in the term. 

Work from our group was the first to demonstrate that resting intracellular free calcium ([Ca2+]j) levels are elevated, both in isolated, non-enzymatically-treated myofibers (Turner et al., 1988) and in cultured myotubes (Fong et al., 1990). Since... 

Fig. 9. Schematic energy level diagrams for Nd3+ in various MPO4 and MBO3 crystals, showing the positions of the 4f"5d and 2G(2)j levels (from Wegh et al., 2001). Levels exhibiting emission are marked with a semicircle.

---