Resonance condition interactions

Before we develop the resonance conditions for systems with hyperhne and with zero-held interactions, we return to the electronic Zeeman term S B as an example interaction to discuss a hitherto ignored complexity that is key to the usefulness of EPR spectroscopy in (bio)chemistry, namely anisotropy the fact that all interactions... 

Let us rewrite the resonance condition of an S = 1/2 system subject to the Zeeman interaction only as... 

When the hyperfine interaction is much smaller than the Zeeman interaction ( much means approximately two orders of magnitude or more), as is usually the case in X-band, then the resonance condition is... 

The example of nitrogen lines in the spectrum of cobalamin points to the necessity of also writing out resonance conditions for the presence of ligand hyperfine interaction. In general we have ... 

In general, no simple, consistent set of analytical expressions for the resonance condition of all intradoublet transitions and all possible rhombicities can be derived with the perturbation theory for these systems. Therefore, the rather different approach is taken to numerically compute all effective g-values using quantum mechanics and matrix diagonalization techniques (Chapters 7-9) and to tabulate the results in the form of graphs of geff,s versus the rhombicity r = E/D. This is a useful approach because it turns out that if the zero-field interaction is sufficiently dominant over... 

The superhyperfine splittings are sufficiently small to ignore second-order effects at X-band, and for adducts of the nitrone compounds splitting from the nitrone-N and the beta-H are the only resolved hyperfine interactions, thus affording the extremely simple resonance condition (cf. Equation 5.10)... 

Here 2tt Aft = trm is imposed to eliminate the effect by the zero-order interaction of the RF field, otherwise a term containing Ix will remain and it will distort the longitudinal magnetization, transverse magnetization, as well as the BSPS of the 13C . For the on-resonance condition, 5 = 0, all the higher-order average Hamiltonians vanish since [7f(/ ), = 0 for arbitrary l and... 

What is the mechanism by which this energy transfer occurs 86) Figure 9 shows that should happen. We start with the system S (excited)-)- A (ground state) and end up with the system S (ground state) -f A (excited). This is only possible, if one of the levels of A lies at the same height as the luminescent level of S (resonance condition). Further we need an interaction between S and A. 

Perhaps enzyme-substrate recognition and interaction are facilitated by an oscillating active site Its correlated motion could position more readily and reliably the catalytically essential groups of atoms. Recognition of the substrate could be visualized as a nonlinear resonance phenomenon, perhaps providing the mechanism of energy transfer from the entatic active site region to the substrate. An off-resonance condition could characterize an enzyme-inhibitor interaction. 

When an electron is injected into a polar solvent such as water or alcohols, the electron is solvated and forms so-called the solvated electron. This solvated electron is considered the most basic anionic species in solutions and it has been extensively studied by variety of experimental and theoretical methods. Especially, the solvated electron in water (the hydrated electron) has been attracting much interest in wide fields because of its fundamental importance. It is well-known that the solvated electron in water exhibits a very broad absorption band peaked around 720 nm. This broad absorption is mainly attributed to the s- p transition of the electron in a solvent cavity. Recently, we measured picosecond time-resolved Raman scattering from water under the resonance condition with the s- p transition of the solvated electron, and found that strong transient Raman bands appeared in accordance with the generation of the solvated electron [1]. It was concluded that the observed transient Raman scattering was due to the water molecules that directly interact with the electron in the first solvation shell. Similar results were also obtained by a nanosecond Raman study [2]. This finding implies that we are now able to study the solvated electron by using vibrational spectroscopy. In this paper, we describe new information about the ultrafast dynamics of the solvated electron in water, which are obtained by time-resolved resonance Raman spectroscopy. 

As shown in Fig. 6b, for a dump laser pulse overlapping with the pump laser pulse no net population transfer occurs. It is particularly interesting that the intermediate level 2 is not significantly populated at any time although level 3 is weakly populated during the interaction. This surprising population dynamics can be exploited to check whether the dump laser frequency is in resonance with the 2 - 3 transition and thus the double-resonance condition is fulfilled As in SEP experiments it is possible to monitor the population of level 2 either by fluorescence from level 2 or by ionization after absorption of an additional photon (see Fig. 4). In a simple model the ionization process from level 2 can be introduced by a time-dependent decay rate of level 2 [6, 60] that is proportional to the intensity of the laser pulses, whereas the fluorescence is only proportional to the population in level 2 after interaction with both laser pulses [54]. 

We have considered here the influence of dispersion asymmetry and Zee-man splitting on the Josephson current through a superconductor/quantum wire/superconductor junction. We showed that the violation of chiral symmetry in a quantum wire results in qualitatively new effects in a weak superconductivity. In particularly, the interplay of Zeeman and Rashba interactions induces a Josephson current through the hybrid ID structure even in the absence of any phase difference between the superconductors. At low temperatures (T critical Josephson current. For a transparent junction with small or moderate dispersion asymmetry (characterized by the dimensionless parameter Aa = (vif — v2f)/(vif + V2f)) it appears, as a function of the Zeeman splitting Az, abruptly at Az hvp/L. In a low transparency (D Josephson current at special (resonance) conditions is of the order of yfD. In zero magnetic field the anomalous supercurrent disappears (as it should) since the spin-orbit interaction itself respects T-symmetry. However, the influence of the spin-orbit interaction on the critical Josephson current through a quasi-ID structure is still anomalous. Contrary to what holds... 

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