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Cross-polarization (CP), originally published as proton-enhanced nuclear induction spectroscopy (PENIS) [1] [2] is a solid-state nuclear magnetic resonance (ssNMR) technique to transfer nuclear magnetization from different types of nuclei via heteronuclear dipolar interactions.
Polarization can be used to filter out unwanted signals, such as jamming. If a jammer and receiver do not have the same polarization, the jamming signal will incur a loss that reduces its effectiveness. The four basic polarizations are linear horizontal, linear vertical, right-hand circular, and left-hand circular.
Nuclear Overhauser Effect Spectroscopy (NOESY) is a 2D NMR spectroscopic method used to identify nuclear spins undergoing cross-relaxation and to measure their cross-relaxation rates. Since 1 H dipole-dipole couplings provide the primary means of cross-relaxation for organic molecules in solution, spins undergoing cross-relaxation are those ...
Dithiane chemistry is a classic example of polarity inversion. This can be observed in the Corey-Seebach reaction. Ordinarily the oxygen atom in the carbonyl group is more electronegative than the carbon atom and therefore the carbonyl group reacts as an electrophile at carbon.
The Raman cross section for the vibration of the aromatic ring in toluene around 1000 cm −1 is on the order of 10 −29 cm 2 /molecule·steradian. Therefore, the Raman signal is around 26×10 −23 W/molecule·steradian or 3.3×10 −21 W/molecule (over 4π steradians). That is 0.014 photon/sec·molecule.
In chemistry, polarity is a separation of electric charge leading to a molecule or its chemical groups having an electric dipole moment, with a negatively charged end and a positively charged end. Polar molecules must contain one or more polar bonds due to a difference in electronegativity between the bonded atoms.
Polarization mode dispersion, polarization-dependent loss. and cross-polarization modulation are other phenomena that can cause problems in PDM systems. For this reason, PDM is generally used in conjunction with advanced channel coding techniques, allowing the use of digital signal processing to decode the signal in a way that is resilient to ...
Jamming during discharge of granular material is due to arch formation (red spheres) Jamming is the physical process by which the viscosity of some mesoscopic materials, such as granular materials , glasses , foams , polymers , emulsions , and other complex fluids , increases with increasing particle density.