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Configuration shifts

In keeping with tlie arrangements ot Mayer s magnets, Thoinrou s configuration shifted to a second ring at six electrons, wailed until 10 electrons lo add a first electron to the sec-... [Pg.36]

Step 1. The substrate, RH, associates with the active site of the enzyme and perturbs the spin-state equilibrium. Water is ejected from the active site and the electronic configuration shifts to favor the high-spin form in which pentaco-ordinated heme Fe3+ becomes the dominant form-binding substrate. In this coordination state, Fe3+ is puckered out and above the plane in the direction of the sixth ligand site. The change in spin state alters the redox potential of the system so that the substrate-bound enzyme is now more easily reduced. [Pg.36]

A similar effect as in the case of CsSmp has been observed by Yoo et al. (1991). In their study on the Sm2+ ions in SrF2 they could demonstrate an electronic crossover connected with a phase transition starting at pressures around 4.5 GPa. At this pressure, the f-d configuration shifted below the 5Dq multiplet. [Pg.549]

Analysis of the charge transfer (CT) NLO mechanism in the four-wave mixing configuration (shifts in oscillator strength as a result of photoinduced charge transfer) leads to an expression for the intensity of the diffracted wave [45] ... [Pg.162]

Fig. 16.2 A model for the energetics of electron transfer reactions. The two potential surfaces are associated with two electronic states that transform to each other when the electron is transferred. The coordinate X stands for the nuclear configuration. The model may be characterized by the curvature of these surfaces, by the energy gap AE between the two electronic origins and by the reorganization energy Ex. Other important parameters that can be expressed in terms of these are the equilibrium configuration shift Ay, — Xa and the activation energy E. ... Fig. 16.2 A model for the energetics of electron transfer reactions. The two potential surfaces are associated with two electronic states that transform to each other when the electron is transferred. The coordinate X stands for the nuclear configuration. The model may be characterized by the curvature of these surfaces, by the energy gap AE between the two electronic origins and by the reorganization energy Ex. Other important parameters that can be expressed in terms of these are the equilibrium configuration shift Ay, — Xa and the activation energy E. ...
The configuration shift results from a configuration change from G , the real bulk configuration, to G the configuration supposed to occur at the surface. The two remaining contributions can be evaluated within the density functional formalism. [Pg.34]

This paper deals with the control of weld depth penetration for cylinders in gold-nickel alloy and tantalum. After introducing the experimental set-up and the samples description, the study and the optimization of the testing are presented for single-sided measurements either in a pulse-echo configuration or when the pump and the probe laser beams are shifted (influence of a thermal phenomenon), and for different kind of laser impact (a line or a circular spot). First, the ultrasonic system is used to detect and to size a flat bottom hole in an aluminium plate. Indeed, when the width of the hole is reduced, its shape is nearly similar to the one of a slot. Then, the optimization is accomplished for... [Pg.693]

Then, the weld depths penetration are controlled in a pulse-echo configuration because the weld bead (of width 2 mm) disturbs the detection when the pump and the probe beams are shifted of 2.2 mm. The results are presented in figure 8 (identical experimental parameters as in figure 7). The slow propagation velocities for gold-nickel alloy involve that the thermal component does not overlap the ultrasonic components, in particular for the echo due to the interaction with a lack of weld penetration. The acoustic response (V shape) is still well observed both for the slot of height 1.7 mm and for a weld depth penetration of 0.8 mm (lack of weld penetration of 1.7 mm), even with the weld bead. This is hopeful with regard to the difficulties encountered by conventional ultrasound in the case of the weld depths penetration. [Pg.698]

The third alternative is a more robust, sensitive and specialized fonn of the first, in that only hydrogen nuclei indirectly spin-spin coupled to in a specific molecular configuration are imaged. In achieving selectivity, the technique exploits the much wider chemical shift dispersion of compared to H. The metliod involves cyclic transfer from selected H nuclei to indirectly spin-spin coupled C nuclei and back according to the sequence... [Pg.1533]

Figure Bl.26.10. Various polarization configurations corresponding to different values of the phase shift, 4)... Figure Bl.26.10. Various polarization configurations corresponding to different values of the phase shift, 4)...

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See also in sourсe #XX -- [ Pg.2 , Pg.3 , Pg.115 , Pg.187 , Pg.192 , Pg.209 , Pg.210 , Pg.215 , Pg.225 , Pg.229 , Pg.241 , Pg.246 , Pg.274 ]




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