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  2. Cross-polarization - Wikipedia

    en.wikipedia.org/wiki/Cross-polarization

    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.

  3. XPIC - Wikipedia

    en.wikipedia.org/wiki/XPIC

    It is typically necessary in Polarization Division Multiplexing systems: the data sources to be transmitted are coded and mapped into QAM modulating symbols at the system's symbol rate and upconverted to a carrier frequency, generating two radio streams radiated by a single dual-polarized antenna (see feed pattern of Parabolic antenna).

  4. Electronic counter-countermeasure - Wikipedia

    en.wikipedia.org/wiki/Electronic_counter...

    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.

  5. Nuclear Overhauser effect - Wikipedia

    en.wikipedia.org/wiki/Nuclear_Overhauser_effect

    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 ...

  6. Insensitive nuclei enhanced by polarization transfer - Wikipedia

    en.wikipedia.org/wiki/Insensitive_nuclei...

    Insensitive nuclei enhancement by polarization transfer (INEPT) is a signal enhancement method used in NMR spectroscopy. It involves the transfer of nuclear spin polarization from spins with large Boltzmann population differences to nuclear spins of interest with lower Boltzmann population differences. [ 1 ]

  7. Chemical polarity - Wikipedia

    en.wikipedia.org/wiki/Chemical_polarity

    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.

  8. Magic angle spinning - Wikipedia

    en.wikipedia.org/wiki/Magic_angle_spinning

    Magic-angle spinning: The sample (blue) is rotating with high frequency inside the main magnetic field (B 0). The axis of rotation is tilted by the magic angle θ m with respect to the direction of B 0. In solid-state NMR spectroscopy, magic-angle spinning (MAS) is a technique routinely used to produce better resolution NMR spectra.

  9. Umpolung - Wikipedia

    en.wikipedia.org/wiki/Umpolung

    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.