A presaturation pulse sequence has been used to observe exchangeable hydrogen atoms by 1H FT NMR in H2O. It is shown that by varying the length of the presaturation pulse, the peak areas, the spin-lattice relaxation times, and the rates of exchange of these hydrogens may be determined, ...
The superconducting state of NaCoO·yHO with three CoOlayers in a unit cell has been studied by Co-NMR. The Knight shift measured for a peak of the NMR spectra corresponding to the external magnetic field H along one of the principal directions within the CoOplane, exhibits a rapid decrease...
We present a 17O and 1H NMR study of molecular endofullerene H2O@C60 dissolved in the nematic liquid crystal N-(4-methoxybenzylidene)-4-butylaniline (MBBA). The 17O NMR peak is split into five components by the 17O residual quadrupolar coupling, each of which is split into a triplet by...
A modification to the recently proposed α/β-HN(CO)CA-J TROSY pulse sequence (P. Permi et al., J. Magn. Reson.146, 255–259 (2000)) makes it possible to determine 3J(Hαi, Ni+1) coupling constants from a single E.COSY-type cross-peak pattern rather than from two 1Hα spin-st...
in this photocatalytic system. In order to further verify the origin of HCOOH, the13CO2isotope trace experiment was performed. The13C NMR spectrum gave the corresponding isotope H13COOH signal with a peak at 168.4 ppm, and there was no such signal under the same condition as for12CO2(Fig....
Corresponding to the suppression of the free OH band, the absorption peak of the H-bonded OH stretch band rises at ∼3350 cm(-1). This spectral change is interpreted in terms of a signature of four-coordinated water sites in the clusters. 展开 ...
In contrast, for samples of DG and TCG, there are only "adsorbed water" and "macro-capillary water" peaks; the "bulk water" peak is negligible. The subbituminous coal TCG and high volatile bituminous coal DG contain no significant bulk water as a result of poor development of cleats to ...
Thermal analysis in combination with XRD and SEM, revealed that in the CaO-Al 2 O 3 -SiO 2 -H 2 O system the amount of hydrogarnet formed was the largest when gibbsite was used as the Al source, smallest for kaolin and intermediate for metakaolin. The endotherm peak temperature of the ...
Peak value of δ 155.33 (NH-C-C=N) in 13C NMR further confirmed the formation of tetrazole. In addition, melting point of the synthesized tetrazole (214-216 0C) derived from benzaldehyde (model reaction) matched with the reported data31. Another significant component in the current procedure...
In a typical USANS experiment rocking curve proffiiles are measured by rotating the analyzer crystal across the peak position and measuring the neutron intensity as a function of the momentum transfer (or scattering vectorr)) q at which data are collectedd at one value of q (or θθ)) at...