Results 241 to 250 of about 1,099,567 (306)

Nitrogen-15: Microbiological Alteration of Abundance

Science, 1968
The abundance of N 15 relative to N 14 is significantly altered during experiments in vitro in which nitrate and nitrite are microbiologically reduced to nitrogen gas. In all studies to date, N 14 O 3 - and N 14
R P, Wellman, F D, Cook, H R, Krouse
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ChemInform Abstract: NITROGEN‐15 ‐ NITROGEN‐15 COUPLING CONSTANTS AND ROTATIONAL BARRIERS OF NITROSAMINES

Chemischer Informationsdienst, 1984
AbstractDie Verbindungen (I)‐(V), in denen die NO‐Gruppe "N‐markiert (99%) ist, werden "N‐ NMR‐spektroskopisch untersucht.
H. BANDMANN, P. HEYMANNS, C. SIEM, P. RADEMACHER   +3 more
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Variations of Nitrogen-15 Abundance in Soils

Science, 1964
A survey of the isotopic composition of soil nitrogen has shown that there is variation in the abundance of nitrogen-15 in soils and in different forms of soil nitrogen. The variation detected is small, but it cannot be attributed to analytical errors and should be considered in studies of nitrogen transformation in soils when nitrogen-15 is used as a ...
H H, Cheng, J M, Bremner, A P, Edwards
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The influence of nitrogen-15 proton-driven spin diffusion on the measurement of nitrogen-15 longitudinal relaxation times

Journal of Magnetic Resonance, 2007
The effect of nitrogen-15 proton-driven spin diffusion on quantitative (15)N T(1) measurements in solid proteins is investigated, and the impact on the measurement of dynamic parameters is assessed. A simple model of exchange between neighboring nitrogens is used to reproduce the evolution of (15)N spin systems whose longitudinal relaxation rates and ...
Giraud, N., Blackledge, M., Bockmann, A., Emsley, L.   +3 more
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Dynamic nuclear polarization of nitrogen-15 in benzamide

Solid State Nuclear Magnetic Resonance, 1997
A 15N dynamic nuclear polarization (DNP) experiment is reported in which a 15N DNP enhancement factor of approximately 2.6 x 10(2) is obtained on free radical doped samples of 99% 15N labeled benzamide. The free radicals BDPA (1:1 complex of alpha, gamma-bisdiphenylene-beta-phenylallyl with benzene) and DPPH (2,2-Di(4-tert-octylphenyl)-1-picrylhydrazyl)
J Z, Hu, J, Zhou, B, Yang, L, Li, J, Qiu, C, Ye, M S, Solum, R A, Wind, R J, Pugmire, D M, Grant   +9 more
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Nitrogen‐15 NMR spectroscopy: Nitrogen‐15 chemical shifts of alkylthioureas

Magnetic Resonance in Chemistry, 1991
AbstractNitrogen‐15 chemical shifts of alkylthioureas in dimethylsulphoxide and pyridine are reported.
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Nitrogen-15 chemical shifts and carbon-13-nitrogen-15 coupling constants of cyanide complexes

Inorganic Chemistry, 1982
The /sup 13/C NMR spectra of cyanide complexes have been reported by Hirota et al. and Pesek et al. However, no reports have been found concerning /sup 15/N resonances and C-N nuclear-spin coupling constants, J/sub C-N/, for cyano complexes. The data for J/sub C-N/ and /sup 15/N and /sup 13/C resonances may be useful in interpreting the NMR spetra of ...
Mitsuru Sano, Yuzo Yoshikawa, Hideo Yamatera   +2 more
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Nitrogen-15 spin relaxation in oximes

Journal of Magnetic Resonance (1969), 1979
Abstract 15N NMR spectral parameters are reported for several aldoximes and ketoximes. Syn and anti isomers are resolved and observed for acetaldoxime and propanaldoxime. 15N spin-lattice relaxation times (T1's) for the non-protonated nitrogens in these small molecules are not excessively long (∼25 to 50 sec).
George C Levy, Allen Godwin, Clive E Holloway   +2 more
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Nitrogen‐15 in apple nutrition investigations

Journal of the Science of Food and Agriculture, 1975
AbstractYoung apple trees growing in pots of soil were treated with N‐15 labelled potassium nitrate or urea at different times of year. Over periods of several months whole trees were harvested and divided into their component tissues for total N and N‐15 analyses; the latter were carried out using an emission spectrometer.
Dennis G. Hill‐Cottingham, Charles P. Lloyd‐Jones   +1 more
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Nitrogen‐15‐Depleted versus Nitrogen‐15‐Enriched Ammonium Sulfate as Tracers in Nitrogen Uptake Studies

Soil Science Society of America Journal, 1974
Abstract Fertilizer particles were prepared from ammonium sulfate with a lower (0.031) than natural (0.366) atom percentage of 15 N. The 15 N‐depleted material was compared with ammonium sulfate of a comparable level of
A. P. Edwards, R. D. Hauck
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