Nuclear magnetic resonance experiment

Carr H Y and Purcell E M 1954 Effects of diffusion on free precession in nuclear magnetic resonance experiments Rhys. Rev. 94 630-8... 

Aqueous GPC can also be semiprepped in manner just like nonaqueous GPC. In this case one must consider carefully the buffers, salts, and biocides used in the eluant. If the fractions are destined for nuclear magnetic resonance experiments it will be imperative to either reduce the salt concentration in the eluant or remove salt after the initial fractionation. Likewise, if the collected samples are destined for infrared (IR) analysis, it is important to choose salts and buffers that have good IR transparency in the wavenumber ranges of interest. 

D. I. Hoult, R. E. Richards 1976, (The signal-to-noise ratio of the nuclear magnetic resonance experiment), J. Magn. Reson. 24, 71. 

Y. Pan, P- F rotational-echo double resonance nuclear magnetic resonance experiment on fluoridated hydroxyapatite. Solid State Nucl. Magn. Reson. 5 (1995) 263-268. L. Wu, W. Forsling, P.W. Schindler, Surface complexation of calcium mineral in aqueous solution, surface protonation at fluorapatite surface, J. Colloid Interface Sci. 147 (1991) 178-185. 

Nerdal, W. and Andersen, 0.M., Intermolecular aromatic acid association of an anthocyanin (petanin) evidenced by two-dimensional nuclear Overhauser enhancement nuclear magnetic resonance experiments and distance geometry calculations, Phytochem. Anal, 3, 182, 1992. 

Inverse-Detected 15N Nuclear Magnetic Resonance Experiments... 

The models in Figures 2 and 3 show that a part of the low molecular weight liquid obviously separates the polymer chains from each other, thus facilitating segment mobility. Another part of it fills the cavities and displays almost liquid state behavior in them. This rather simplified model of the glass structure has been verified in some by nuclear magnetic resonance experiments. 

D. The table below shows signal-to-noise ratios recorded in a nuclear magnetic resonance experiment. Construct graphs of... 

The small difference in population among the Af/ or Ms levels allows the magnetic resonance experiments. From now on we will focus on the nuclear magnetic resonance experiment, but little would be changed if we dealt with EPR. 

The previous three chapters have shown that nuclear magnetic resonance experiments with 1H and 13C nuclei are enormously useful to the chemist working with organic compounds. There is no need, however, to limit ourselves to these two important nuclei. Indeed, there are 120 different nuclei whose spin number, /, is greater than zero and, therefore, theoretically observable in an NMR experiment. Of these 120 nuclei, 31 of them are dipolar, which means that their spin number is one-half (/ = ). 

The application of Fourier transform methods to nuclear magnetic resonance experiments improved the signal-to-noise ratio and permitted extraction of data heretofore inaccessible. 

Recent single-molecule experimental studies of proteins provide more detailed views of protein motions, and confirm that a wide variety of timescales is involved in, e.g., catalytic action of enzymes [7,14,15,19,33], Of course, molecular dynamics simulations have been used to probe motions in single proteins for many years, and advances in both theory and computational science have made simulations a powerful approach to building theoretical understanding of protein dynamics [1], The recent introduction of accelerated molecular dynamics methods is helpful in this context [11]. Although detailed dynamical information is sacrificed to the enhanced sampling of conformational space in these methods, which have been shown to access conformational fluctuations that are revealed by nuclear magnetic resonance experiments on the millisecond... 

Saturation transfer difference nuclear magnetic resonance experiments have shown that there is a strong interaction between the enzyme and the (R)-enantiomers of the alcohols, but not the (S)-enantiomers (H. W. Anthonsen, unpublished results). As described above, addition of a small amount of pure (R)-alcohols increased the 5-value of kinetic resolution and, moreover, the effect disappeared quickly. The reason is probably that the alcohol moves into the active site where it is esterified. A future goal is to find an additive that can bind irreversibly to this unknown allosteric site, thus causing a lasting effect. 

Carr HY, Purcell EM. Effects of diffusion on free preces- 46. sion in nuclear magnetic resonance experiments. Phys. Rev. 1954 94 630. 

Okamoto, Cooper, and Root (1992) derived the following expectation model of coupled spin relaxation of and C nuclei for their nuclear magnetic resonance experiments with block copolymers ... 

In the case of colorless aqua ions, one has to use other techniques. The hona fide existence of Be(H20)4" Al(H20)6 and Ga(H20)6" is indicated by nuclear magnetic resonance experiments (12). Eigen (19) reviewed the various techniques available for very short-lived aqua ions. The alkaline metal ions, Ba(II), Sr(II), Ca(II), and surprisingly enough... 

Jost S, Bar NK, Fritzsche S, Haberlandt R, and Karger J. Diffusion of a mixture of methane and xenon in silicalite A molecular dynamics study and pulsed field gradient nuclear magnetic resonance experiments. J Phys Chem B 1998 102 6375-6381. 

Nuclear magnetic resonance experiments indicate that both staggered and eclipsed conformations of substituted arene chromium tricarbonyls exist in solution 177, 235). The preferred conformations are attributed to both steric and electronic effects. 

X-ray experiments show that RbaCeo also has the same fee structure.[F191b, St92a, Zh91b] However, that conclusion seems to be inconsistent with recent Rb nuclear magnetic resonance experiments, which indicate that the tetrahedral cations are not all equivalent.[Wa93]... 

P. Mansfield, M. J. Orchard, D. C. Stalker and K. H. B. Richards, Symmetrized multipulse nuclear-magnetic-resonance experiments in solids measurement of the chemical-shift shielding tensor in some compounds. Phys. Rev., 1973, B7, 90-105. 

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