Full-text resources of PSJD and other databases are now available in the new Library of Science.
Visit https://bibliotekanauki.pl
Preferences help
Polish version English version Language
enabled [disable] Abstract
Number of results

Results found: 2

Number of results on page
first rewind previous Page / 1 next fast forward last

Search results

help Sort By:

help Limit search:
first rewind previous Page / 1 next fast forward last
1
Content available remote

Single-Quantum NMR Spinning-Side-Band Patterns for Spin-3/2 System

100%
Lupulescu A., Fechete R., Demco D. E., Cozar O.
Acta Physica Polonica A
|
1997
|
vol. 92
|
issue 6
1125-1134
EN
The NMR response of an isolated spin-3/2 system with an axially symmetric quadrupolar interaction under magic-angle sample spinning to an ideal radio-frequency pulse using irreducible tensor operators is evaluated analytically. The excited single-quantum spin coherences are modulated by the sample spinning. The effects of spinning frequency, quadrupole coupling constant and the orientation of quadrupolar interaction relative to rotor axis on the spinning-side-band patterns are simulated. High-resolution single-quantum spinning-side-band pattern detected for ^{23}Na (I=3/2) nuclei in sodium nitrate powder is compared with the simulation based on the theory and the quadrupole coupling is estimated.
2
Content available remote

Homonuclear Separated Local-Field Spectroscopy by Magnetization-Exchange NMR

88%
Demco D. E., Filip X., Filip C., Chira D., Cozar O.
Acta Physica Polonica A
|
1997
|
vol. 92
|
issue 6
1135-1149
EN
The possibility to perform homonuclear separated-local field NMR spectroscopy by magnetization-exchange is presented. Solid-state one-dimensional proton magnetization-exchange NMR is used to investigate intergroup residual dipolar couplings in cis-1,4-polybutadiene elastomer. A three-spin model is employed, in which the CH- and CH_{2}-protons are considered to be coupled by residual dipolar interactions. The magnetization-exchange process between the CH- and the CH_{2}-group in the regime of short mixing time provides valuable insight regarding molecular order. The spin-system response reflects well-localized dipolar interactions. The residual intergroup dipolar couplings are measured along the average polymer-chain direction for different temperatures. The dynamic order parameter along the chains is also evaluated.
first rewind previous Page / 1 next fast forward last
JavaScript is turned off in your web browser. Turn it on to take full advantage of this site, then refresh the page.