@article {358, title = {Measurement of dipolar couplings in partially oriented molecules by local field NMR spectroscopy with low-power decoupling}, journal = {Journal of Magnetic Resonance}, volume = {158}, year = {2002}, note = {J Magn Reson619VETimes Cited:8Cited References Count:23}, month = {Sep-Oct}, pages = {52-59}, abstract = {

Low-power phase-modulated Lee-Goldburg homonuclear decoupling was used to record PDLF spectra of fluorine-substituted benzene derivatives dissolved in nematic thermotropic liquid crystalline solvents. The low-power decoupling minimizes sample heating during RE irradiation while still achieving highly resolved PDLF spectra. The method is illustrated by recording spectra for 1,3-dichloro-4-fluoro-5-nitrobenzene, 1,3-dichloro-4-fluorobenzene, and 1, 2-difluoro benzene dissolved in different nematic solvents. (C) 2002 Elsevier Science (USA). All rights reserved.

}, keywords = {resolution}, isbn = {1090-7807}, doi = {Doi 10.1016/S1090-7807(02)00059-9}, url = {://WOS:000179497500006}, author = {Marjanska, M. and Castiglione, F. and Walls, J. D. and Pines, A.} } @article {415, title = {A novel detection-estimation scheme for noisy NMR signals: Applications to delayed acquisition data}, journal = {Journal of Magnetic Resonance}, volume = {128}, year = {1997}, note = {J Magn ResonYc696Times Cited:47Cited References Count:59}, month = {Sep}, pages = {30-41}, abstract = {

Many potentially interesting and useful classes of NMR experiments generate data for which conventional spectral estimation and quantification aa the Fourier transform are unsatisfactory. In particular, recently introduced solid-state NMR experiments which involve long delays before data acquisition fall into this category, as the free induction decays are heavily \&$\#$39;\&$\#$39;truncated\&$\#$39;\&$\#$39; and have low signal-to-noise ratios. A novel detection-estimation scheme is introduced in order to analyze data from such experiments and others where the sensitivity is low and/or the data record is strongly damped or truncated, Based on the assumption of exponential data modeling, the number of signals present is first detected using criteria derived from information theory and the spectral parameters are then estimated using the matrix pencil method, Monte Carlo simulations and experimental. applications are carried out to demonstrate its superior statistical and computational performances and its general applicability to delayed acquisition data. Over the range of note levels investigated, it is found that this approach is essentially near-optimal in the sense that the estimated spectral parameters have biases almost equal to zero and variances very close to their theoretical Cramer-Rao lower bounds. Compared to the popular method of linear prediction with singular value decomposition, this method not only improves the estimation accuracy (by a factor of 2-4) with a lower \&$\#$39;\&$\#$39;break-down\&$\#$39;\&$\#$39; signal-to-noise threshold (approximate to 1.5 dB), but also reduces the computational cost by about an order of magnitude, It also holds great promise in effectively reducing truncation artifacts. It is concluded that this approach not only facilitates the analysis of delayed acquisition data, but can also become a valuable tool in the routine quantification of general NMR spectra, ia listing of programs is also included in the Appendix. (C) 1997 Academic Press.

}, keywords = {resolution}, isbn = {1090-7807}, doi = {Doi 10.1006/Jmre.1997.1215}, url = {://WOS:A1997YC69600004}, author = {Lin, Y. Y. and Hodgkinson, P. and Ernst, M. and Pines, A.} } @article {479, title = {Dynamic-Angle Spinning without Side-Band}, journal = {Chemical Physics Letters}, volume = {210}, year = {1993}, note = {Chem Phys LettLp038Times Cited:18Cited References Count:16}, month = {Jul 30}, pages = {405-410}, abstract = {

By means of rotor-synchronized pi-pulses, it is possible to eliminate the spinning sidebands (while retaining their full intensity in the isotropic centerband) that usually arise in dynamic-angle spinning (DAS) NMR. The theory of this approach, dynamic-angle hopping (DAH-180), is described and illustrated with experimental results on quadrupolar nuclei. A magic-angle hopping (MAH-180) version of magic-angle spinning is also possible and can be used in a two-dimensional NMR experiment to produce sideband-free isotropic-anisotropic correlation spectra for spin-1/2 nuclei.

}, keywords = {resolution}, isbn = {0009-2614}, doi = {Doi 10.1016/0009-2614(93)87045-5}, url = {://WOS:A1993LP03800018}, author = {Gann, S. L. and Baltisberger, J. H. and Pines, A.} }