Resonance relation

P. J. Kanyha and S. Brey, 22nd Congr. AMPERE Magn. Reson. Relat. Phenom. Proc., 341 (1984). 

Confirmation analysis In most cases, the occurrence of dynamic resonance can be quickly confirmed. When monitoring phase and amplitude, resonance is indicated by a 180° phase shift as the rotor passes through the resonant zone. Figure 44.44 illustrates a dynamic resonance at 500 rpm, which shows a dramatic amplitude increase in the frequency-domain display. This is confirmed by the 180° phase shift in the time-domain plot. Note that the peak at 1200 rpm is not resonance. The absence of a phase shift, coupled with the apparent modulations in the FFT, discount the possibility that this peak is resonance-related. 

The following are rules that apply to drawing resonance structures. Remember that resonance relates to different ways of placing electrons in the structures, not ways of arranging the atoms themselves. 

Conclusions, some of them contrary to the above, were reached more recently by Zhuang et al. (145) from a combination of 31P and 1H MAS NMR spectroscopy of adsorbed trimethylphosphine. These authors found not only Lewis acid sites (vide infra), but also Brpnsted acid sites in TS-1 (145). They claimed that the 1H, 29Si MAS NMR spectra and the resonance related to Brpnsted acid sites in the 31P MAS NMR demonstrated clearly that the presence of Ti in the framework results in the formation of a new OH group, titanols, which is more acidic than the silanols of silicalite-1 (145) . The peak at 4.3 ppm in the 31P MAS NMR spectra was assigned to a ((CH3)3P-H)+ complex arising from the interaction of (CH3)3P with Brpnsted acid sites present on TS-1. The origin of this proton is not clear at present, especially because the MAS NMR spectra of the same TS-1 samples did not differ significantly from those of silicalite-1 (145) the latter, when free from impurities, is not known to be a Brpnsted acid. 

With substituted phenols, there can be similar delocalization of charge into the aromatic ring as with phenol, but substituents will introduce their own effects, be it inductive or resonance related. It can be seen that the nitro group allows further... 

Conjugated Dipole absorption-A specific type of dipole absorption represented by a structural resonance related to the conjugated backbone of a molecule and characterized by isotropic absorption in the visual spectmm. 

A. Raizman and J. T. Suss, Magn. Reson. Relat. Phenom., Proc. Congr. Ampere 18th, 1974, 1, 121 (Chem. Abslr.,... 

Then the resonance-relations of the hexagons e B exactly match the edge-incidence relations of the-edges T Since a caterpillar tree T (mj, m2, —, m ) is constructed by the addition of m. monovalent vertices to v. of a path P the proposition is proved, i e T (m,m., > -------------------------------------.. ... 

Fiber optic chemical and biological sensors, based on SPR in continuous metallic films deposited on optical fibers, have been previously reported. " Sensors based on optical fibers have advantages like high response times, ability to be remotely interrogated, and low electromagnetic interference. In our study, fiber optic devices were developed based on excitation of LSPs in gold nanoparticles, deposited on the surface and tip of different optical fiber stractures. As refractive index of the medium around the sensors was varied, or biological molecules attached to the nanoparticles, a shift in the plasmon resonance related dip in the transmission spectram was observed. 

The spectral response of fiber tip based sensors are shown in Figure 5. It was observed that in air, the position of the plasmon resonance related dip was -526 nm. When the fiber sensor was placed in methanol, having a refractive index of 1.33, the plasmon resonance related dip moved to 541 nm and when it was placed in acetone, having a refractive index of 1.36, the plasmon resonance related dip moved to 545 nm. 

Figure 6. Spectral response of in-line fiber structiwes having gold nanoparticles on their surface showing the shift in plasmon resonance related dip when placed in water for (A) Shncture A (B) Shncture B. Lines labeled P are in air and lines labeled Q are in water. Figiwe reprinted from Optics Letters. ...

Figure 7. (A) Shift in plasmon resonance peak wavelength upon addition of Biotin Peak wavelength before Biotin addition was at 539.48 nm (P), right after Biotin addition was at 546.36 nm (Q), 1 minute after Biotin addition was at 547.85 nm (R), 2 minutes after Biotin addition was at 548.8 nm (S), 3 minutes after Biotin addition was at 548.88 nm (T), and (B) Response of Streptavidin addition to a Biotin coated fiber The value of the wavelength at which plasmon resonance-related dip occurs was plotted vs. time for an in-line fiber optic biosensor based on structure A.

Figure 7 shows extinction spectra calculated for randomly oriented linear chains of 13-nm gold spheres with interparticle spacing 1.1 mn. It is the same model that has been considered in Ref [70]. We note two spectral resonances related to the transversal and longitudinal (red-shifted) plasmon excitations. Such properties are analogous to the randomly oriented metal spheroids [45, 72]. By contrast to Fig. 8 in Ref [70], we conclude that random chain orientations do not eliminate the red-shifted longitudinal resonance. Perhaps, the spectra of Fig. 8 from [70] were calculated with an insufficiently large multipole expansion order. 

R 519 H. Murai, S. Yamauchi, A. Kawai, K. Obi and N. Hirota, Developments of Magnetic-Resonance-Related Spin Chemistry in Japan , Appl. Magn. Reson., 2003, 23, 249... 

Moel Mobius, K., Van Willigen, H., Maki, A.H. Magn. Resonance Relat. Phenomena, Proc. Congr. AMPERE, 16th 1970,1114. 

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