Planar coupling

The planar coupling coefficient kp is related to the parallel and series resonant frequencies by... 

Planar zero-quantum coupling tensors are characteristic for most heteronuclear Hartmann-Hahn experiments (see Section XI). Here the effective coupling constant between two heteronuclei i and j is scaled by s, <1/2 [see Eq. (115)]. Planar /-coupling tensors (with... 

For the case of three coupled spins 1 /2 with planar coupling tensors (C = P), analytical polarization-transfer functions have been reported. 

If the coupling constants are known in advance, the total mixing time can be reduced in multiple-step selective coherence-transfer experiments by using the selective homonuclear analog of the optimized heteronuclear two-step Hartmann-Hahn transfer technique proposed by Majumdar and Zuiderweg (1995). In this technique [concatenated cross-polarization (CCP)] a doubly selective transfer step (DCP) is concatenated with a triple selective mking step (TCP). For the case of a linear three-spin system with effective planar coupling tensors, a CCP experiment yields complete polarization transfer between the first and the third spin and the total transfer... 

In 7 5 spin systems, coherence-order-selective coherence transfer (COS-CT), for example, from 2S to F , can be achieved with the help of an effective planar coupling Hamiltonian of the form +... 

Fig. 11. Energy dependence of the local susceptibility of YBajCujOs, 5 for the (a) acoustic and (b) optic spin-wave modes. The optic mode gap of 74meV implies an inter-planar coupling of llmeV From Hayden et al. (1998).

As stated above the SQUID amplifier demands a low inductance Eddy current probe in order to be able to amplify signals up to 1 MHz. Low inductance Eddy current probes can be obtained by reducing the number of turns and by loosing the magnetic coupling between the tums. So magnetic cores should be avoided as well as tight wounded tums. For this purpose planar coils are the best... 

The Champ-Sons model is a most effieient tool allowing quantitative predictions of the field radiated by arbitrary transducers and possibly complex interfaces. It allows one to easily define the complete set of transducer characteristics (shape of the piezoelectric element, planar or focused lens, contact or immersion, single or multi-element), the excitation pulse (possibly an experimentally measured signal), to define the characteristics of the testing configuration (geometry of the piece, transducer position relatively to the piece, characteristics of both the coupling medium and the piece), and finally to define the calculation to run (field-points position, acoustical quantity considered). 

The microwave spectrum of isothiazole shows that the molecule is planar, and enables rotational constants and NQR hyperfine coupling constants to be determined (67MI41700>. The total dipole moment was estimated to be 2.4 0.2D, which agrees with dielectric measurements. Asymmetry parameters and NQR coupling constants show small differences between the solid and gaseous states (79ZN(A)220>, and the principal dipole moment axis approximately bisects the S—N and C(4)—C(5) bonds. 

Reductive coupling reaction of fluonnated vinyl iodides or bromides has been used as a route to fluorinated dienes [246, 247, 248, 249, 250. Generally, the vinyl iodide is heated with copper metal in DMSO or DMF no 1 ntermediate perfluorovmy I-copper reagent is detected. Typical examples are shown m equations 163-165 [246, 247, 249. The X-ray crystal structure of perfluorotetracyclobutacyclooctatetraene, prepared via coupling of tetrafluoro-l,2-diiodocyclobutene with copper, is planar... 

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