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In isotropic solution molecular tumbling reduces the average value of to zero. We thus observe no dipolar coupling. If the solution is not isotropic then the average value of may be different from zero, and one may observe residual couplings.
Magnetic dipole–dipole interaction, also called dipolar coupling, refers to the direct interaction between two magnetic dipoles. Roughly speaking, the magnetic field of a dipole goes as the inverse cube of the distance, and the force of its magnetic field on another dipole goes as the first derivative of the magnetic field. It follows that ...
Solid-state 900 MHz (21.1 T [1]) NMR spectrometer at the Canadian National Ultrahigh-field NMR Facility for Solids. Solid-state nuclear magnetic resonance (ssNMR) is a spectroscopy technique used to characterize atomic-level structure and dynamics in solid materials. ssNMR spectra are broader due to nuclear spin interactions which can be categorized as dipolar coupling, chemical shielding ...
In nuclear chemistry and nuclear physics, J-couplings (also called spin-spin coupling or indirect dipole–dipole coupling) are mediated through chemical bonds connecting two spins. It is an indirect interaction between two nuclear spins that arises from hyperfine interactions between the nuclei and local electrons. [ 1 ]
Dispersion is a process that occurs in soils that are particularly vulnerable to erosion by water. In soil layers where clays are saturated with sodium ions ("sodic soils"), soil can break down very easily into fine particles and wash away. This can lead to a variety of soil and water quality problems, including:
Soil physics is the study of soil's physical properties and processes. It is applied to management and prediction under natural and managed ecosystems . Soil physics deals with the dynamics of physical soil components and their phases as solids , liquids , and gases .
Soil contamination, soil pollution, or land pollution as a part of land degradation is caused by the presence of xenobiotic (human-made) chemicals or other alteration in the natural soil environment. It is typically caused by industrial activity, agricultural chemicals or improper disposal of waste .
They are reactants in 1,3-dipolar cycloadditions. [ 1 ] [ 2 ] The dipole has at least one resonance structure with positive and negative charges having a 1,3 relationship which can generally be denoted as + a−b−c − , where a may be a carbon , oxygen or nitrogen , b may be nitrogen or oxygen, and c may be a carbon, oxygen or nitrogen.