Nuclear magnetic resonance cross-polarisation

The addition of a chemical species with a large dielectric constant to induce desired microwave effects in matrices devoid of such substances, or lacking substances with significantly different dielectric constants, can be compared, on a conceptual basis, to cross-polarisation experiments carried out in nuclear magnetic resonance spectroscopy (see Chapter 6). In that case, a nucleus that relaxes relatively rapidly is excited selectively and allowed to transfer that excitation energy to neighbouring nuclei with low or relatively lower relaxation rate (e.g., nuclei being cross-polarised to nuclei). 

Comparable starch-based materials with an amylose content close to zero, even in the presence of complexing agents, do not show any peak at 947 cm. The V-type structure formation can also be detected using X-ray diffraction analysis and cross-polarisation magic angle spinning solid-state nuclear magnetic resonance [122-125]. 

Cross-polarisation magic angle spinning nuclear magnetic resonance... 

As a result of relaxation, the nuclear Overhauser effect (NOE) is a phenomenon predicted by Albert Overhauser in 1953, which is the fractional change in intensity of one NMR resonance when another resonance is irradiated. It is the transfer of nuclear spin polarisation between nuclei by cross-relaxation and has become indispensable for the determination of the liquid structure of macromolecules, particularly biomolecules, since the first 2D methods were developed by K. Wiithrich, who was awarded the Nobel Prize in Chemistry in 2001 for his work [28]. It was first shown, theoretically, that saturating the electron magnetic resonance in a metal would cause the nuclear resonance intensity to increase by three orders of magnitude (Feiectron/ynuciei) Similar, albeit much less, enhancement was caused between two nuclei... 

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