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Single-crystal samples of the peptide N-acetyl-D,L-valine (NAV) with the exchangeable amide and carboxyl hydrogens replaced by deuterons were investigated by deuterium NMR spectroscopy. The electric field gradient (EFG) and chemical shift (CS) tensors for the amide and the carboxyl hydrogens, both of which are involved in intermolecular hydrogen bonds, were determined. The relationship of these tensors to the structure of NAV is discussed. The orientations of the EFG and the CS tensors of the amide hydrogen in a protein can provide information about the polypeptide backbone structure. For NAV the eigenvector of the largest eigenvalue of the EFG tensor coincides with the NH bond direction, as found by X-ray crystallography, within 2°, and the eigenvector of the intermediate eigenvalue with the normal (n peptide) to the peptide plane within 1°. The directions of largest and smallest shielding are similarly aligned with NH and n peptide respectively. However, the deviations are considerably larger, namely 9° and 11°, respectively. The anisotropy of the CS tensor is determined to be 13.4 +− 2.7 ppm, confirming that the amide hydrogen is involved in a weak hydrogen bond

The muon anomalous magnetic moment has been measured in a new experiment at Brookhaven. Polarized muons were stored in a superferric ring, and the angular frequency difference, v a , between the spin precession and orbital frequencies was determined by measuring the time distribution of highenergy decay positrons. The ratio R of v a to the Larmor precession frequency of free protons, v p , in the storage-ring magnetic field was measured. We find R 3.707 220͑48͒ 3 10 23. With m m ͞m p 3.183 345 47͑47͒ this gives a m 1 1 165 925͑15͒ 3 10 29 (613 ppm), in good agreement with the previous CERN measurements for m 1 and m 2 and of approximately the same precision.

Nuclear magnetic resonance spectra of Cue3 and AlZ7, Gaaa and In115 have been recorded in ternary IB-III-VI, semiconductors, which crystallize in the tetragonal chalcopyrite structure. Nuclear electric quadrupole coupling constants have been determined and are discussed in connection with the structural parameters of these compounds, which were determined by X-ray diffraction.Es wurden die Kernresonanzspektren von Cus3 und AP7, Ga60 und In115 in den ternaren IB-III-VI,-Halbleitern, die in der tetragonalen Chalkopyrit-Struktur kristallisieren, bestimmt. Die elektrischen Kern-Quadrupol-Kopplungskonstanten wurden bestimmt und werden in Verbindung mit den Strukturparametern dieser Verbindungen diskutiert, die durch Rontgenbeugung bestimmt wurden.

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