Saturation frequency

In Chapter 2, ENDOR (electron-nuclear double resonance) was briefly described. To perform an ENDOR experiment it is necessary to apply both a radiofrequency and a microwave frequency, effectively performing simultaneous NMR and ESR, respectively, on the sample. The experiment is performed at a fixed magnetic field, with the ESR saturating frequency centered on a... 

DNP at very low magnetic fields is attractive for two reasons. First, the electron saturation frequency at low fields is in the radiofrequency range, where it is much easier to obtain high-power radiation sources, amplifiers and transmission equipment. In fact, the first experimental verifications of the Overhauser effect were conducted between 1 and 5 mT,2/85/86 likely due to the ease of constructing a suitable magnet and equipment to perform ESR saturation. The second reason for adding DNP to a low-field system is to help overcome the limited thermal polarization at low... 

Magnetization transfer (MT) or cross-relaxation spectroscopy, also termed Z-spectroscopy by Grad and Bryant (1990), has been extensively used to obtain information on the spectral Uneshape of protons in macromolecules as well as on relaxation in heterogeneous systems (Calucd and Forte 2009). A MT spectrum was obtained by performing saturation transfer (ST) experiments at many discrete frequencies and plotting the ratio of the steady-state water signal with and without RF saturation as a function of the saturation frequency offset. For spatially homogeneous samples,... 

Frequency Spectrum of Noise Signal-to-Noise Ratio Noise-Equivalent Power Specific Detectivity (D ) Linearity and Saturation Frequency Response Spatial Considerations Crosstalk... 

Esters Saturated Aryl and a,/3-unsaturated Diesters Oxalates Phthalates C=C—CO—o— Carbamates 1741-1725 1727-1714 1763-1761 1738-1728 1716-1708 1694-1688 Alkyl branching on carbon adjacent to C=0 lowers frequency by 5-15 cm k... 

Molecules such as 3,4 and 5 in Figure 2.6, which have a zero velocity component away from the source, behave uniquely in that they absorb radiation of the same frequency Vj-es whether the radiation is travelling towards or away from R, and this may result in saturation (see Section 2.3.4). If saturation occurs for the set of molecules 3, 4 and 5 while the radiation is travelling towards R, no further absorption takes place as it travels back from R. The result is that a dip in the absorbance curve is observed at Vj-es, as indicated in Figure 2.5. This is known as a Lamb dip, an effect which was predicted by Lamb in 1964. The width of the dip is the natural line width, and observation of the dip results in much greater accuracy of measurement of v es. 

A popular metric of the speed performance of a EET is, the maximum frequency of unity current gain (49). Eor short gate length devices operating at the saturated velocity this metric can be expressed as follows, where... 

In Table 29 the u(C=0) and other characteristic bands are given for some saturated five-membered heterocycles, and compared with the corresponding absorption frequencies for cyclopentanone. Adjacent NH groups and sulfur atoms have the expected bathochromic effect on r (C=0), whereas an adjacent oxygen atom acts in the reverse direction. The CHa vibrations of cyclopentanone are repeated to a considerable extent in the heterocyclic analogs. 

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