Showing papers in "Journal of Magnetic Resonance in 1976"

TL;DR: A fresh approach to the calculation of signal-to-noise ratio, using the Principle of Reciprocity, is formulated, to give the same results as the traditional method of calculation, but its advantage lies in its ability to predict the ratio for other coil configurations.

TL;DR: In this article, a theory has been worked out for the influence of cross relaxation between protons on the relaxation behavior of the protons in a protein at high frequencies, the effect being particularly evident above 10,000 molecular weight at frequencies exceeding 200 MHz.

TL;DR: In this paper, a simple pulse sequence was illustrated by added multiplet subspectra in the Fourier transform 13C NMR of Me2C:CHNMe2.

TL;DR: In this article, a sinusoidal window function was used to filter the high-field region of the 1 H NMR spectrum at 360 MHz of the basic pancreatic trypsin inhibitor.

TL;DR: In this paper, the saturation of a solvent peak is, in most cases, the best method of reducing the dynamic range of a free induction decay from a solution of low concentration, and the factors involved in obtaining a reduction of the order of a thousandfold are discussed.

TL;DR: In this paper, the density matrix formalism developed in a previous paper has been applied to a system containing one spin-1 particle, and the extension of the formalism to an anisotropic phase has been carried out.

TL;DR: In this article, the minimum energy staggered rotamers for the αCH-βCH 2 side-chains of amino acids were estimated from data from model compounds, and the component vicinal coupling constants were derived from the stochastic equation.

TL;DR: In this article, a quick, accurate procedure (LSF method) is developed, using Feynman's theorem, for application of a least-squares-fitting method to the analysis of electron paramagnetic resonance data.

TL;DR: Spin-lattice relaxation times (T1e) of the simple nitroxides 1-oxyl-2,2,6,6-tetra-methyl-4-hydroxypiperidine (tanol), perdeutero-loxyl, 2,2.6, 6,6tetramethyl-4piperidone (tanone), and 15N-substituted tanone were measured from +30 to -85dg as discussed by the authors.

TL;DR: In this paper, the spectrum is broken down into sep. responses from individual C sites in the mol and the magnetic field inhomogeneity is not a fundamental limitation on the resolving power since spin-echo refocusing methods are used to counteract the dispersal of signal components from different regions of the sample.

TL;DR: In this paper, three pulse spacings in T 1 and NOE determinations are considered; viz., acquisition times, pulse delays, and the recovery intervals in the inversion-recovery experiment.

TL;DR: In this paper, the effects of the different substituents and structural features on alkyl carbon chemical shifts are additive, and the dependence of the chemical shift on the protonation state of nearby amino and carboxyl groups is accounted for by having separate substituent parameters for the proptonated and deprotonated forms of amino and carbon substitution.

TL;DR: In this article, the deuterium e2qQ values for N+−D…Cl− bonds are found to follow a similar relation, e 2qQ/h = 239 − (728/R3) kHz, where 282 is the e2Q for a free ND3, molecule and the coefficient of 1R3 is the same as that found for N−D..O bonds where the nitrogen is in a tetrahedral configuration.

TL;DR: In this paper, the Forsen-Hoffman double irradiation method of relating exchange rates to T 1 has been applied to the 13 C NMR spectrum of cis-decalin.

TL;DR: In this paper, the second moment of a methylammonium hexachloroplatinate (IV) ion was measured at various temperatures between 4.2 and 400 K, and the potential barrier for the internal reorientation of the ion was evaluated by using Woessner's method for the analysis of T 1 data.

TL;DR: In this article, an iterative method is presented to evaluate relaxation parameters from experimental data and confidence intervals for the parameters can also be calculated, which is more reliable than semilogarithmic regression.

TL;DR: In this article, the phase of the 90° pulse is shifted by 180° on every repetition of the sequence, while the 180° pulse remains unaltered, and the phase shifted pulse sequence is discussed for a JEOL PFT-100 single phase detector spectrometer.

TL;DR: Membrane permeability to slowly penetrating molecules may be studied using a pulse gradient NMR technique, without otherwise disturbing the system, as illustrated by the measurement of Li+ uptake by human red blood cells.

TL;DR: In this article, a single crystal electron paramagnetic resonance study on Cu(II)-doped in hexaimidazole zinc(1I) dichloride tetrahydrate gives an isotropic quartet spectrum at room temperature with giso = 2.67 gauss.

TL;DR: In this paper, the effect of a misadjusted flip angle on the T1 estimates is discussed for two different estimation methods and a general nonlinear estimation method is developed suitable for the analysis of data from temperature-, frequency-, or pH-dependent T1 studies.

TL;DR: In this article, the spin-lattice relaxation time T1 on the proton Larmor frequency at various temperatures in powdery polyvinyl chloride (PVC) is reported.

TL;DR: Using nuclear double resonance with spin mixing by level crossing (DRLC) the nuclear quadrupole resonance spectrum for 2 D and 7 O have been obtained at 77 K in isotopically enriched Ice II, a proton-ordered high-pressure phase of ice as mentioned in this paper.

TL;DR: In this paper, an approach for the observation of high-resolution NMR spectra in flowing, chemically reacting systems is described, where transient chemical species and effects with lifetimes of less than 1 sec can be detected and their associated kinetic parameters measured.

TL;DR: In this article, the 13 C NMR spectra of 1 and 2-X-naphthalenes (X=NO 2, CHO, CO 2 H, CN, COCH 3, OH, NH 2, F, OCH 3 and CH 3 ) were assigned by selective 13 C{ 1 H} decoupling, 13C{ 1H} off-resonance noise decoupled, and interpretation of 1 H-coupled 13 C spectra.

TL;DR: In this article, the effects of spin echoes in liquids and echo decays in solids caused by the presence of nonresonant nuclei have been studied and conditions for the occurrence of these effects are formulated.