Shift of spectral lines

What is more, the shape and shift of spectral lines tell us about the motions of emitting or absorbing atoms. Temporal variations in light emissions inform us of the stable or changing nature of the phenomena that cause them. 

Stark effect Sphtting or shifts of spectral lines in an electric field. Also called elec-trochromic effect. 

Zeeman effect The splitting or shift of spectral lines due to the presence of external magnetic field. 

Efforts to determine Neptune s rotation period from Earth-based observations using spectroscopy to find it from Doppler shifts of spectral lines across Neptune s disk and searches for periodic brightness changes gave conflicting and almost always incorrect results. 

Once spectra have been obtained, it is necessary to obtain valid assignments for each resonance. As a first step, comparison of chemical shifts of spectral lines with shifts of known metabolites obtained in vitro under physiological conditions (see Fig. 10) permits tentative assignments. These tentative assignments can be checked by conventional analysis of tissue extracts, to see if the amount observed in the extract corresponds to the amount indicated by the in vivo spectrum. Another approach is to obtain spectra of extracts as a function of pH, assigning on the basis of pK [17]. These approaches become less reliable as spectra become more complex (as is often the case for in vivo (see, e.g., Ref. 18) and H-NMR [19] (Fig. 16)), or broad, overlapping lines are encountered (e.g., the monophosphate ester region of P-NMR spectra). 

As mentioned, stellar spectra with right circular polarization obtained in the first exposure and left circular polarization in the second exposure are projeeted in turn on the same section of the CCD detector. Thus, errors in the flat-fielding procedure for two spectra with opposite eireular polarization are practically the same and do not affect the calculation of GMF in the ease of weak magnetic fields. Additionally, this observational technique automatieally allows us to rale out shifts of spectral lines caused by inaccurate adjustment of the CCD plane to the focal plane of the spectrograph and instrumental drift of contours of spectral lines during the second exposure relative to the first one. 

The results which follow allow us to derive conclusions concerning glasses and aqueous solutions with respect to the following parameters 1. change in line intensity, 2. shift of spectral lines, and 3. splitting and broadening of the spectral lines. 

James, D.F.V. E. Wolf (1994) A class of scattering media which generate Doppler-like frequency shifts of spectral lines, Phys. Lett., 1994 (188) 239-244. 

The combination of laser- and mass-spectrometry has brought a wealth of new information on the structure and dynamics of molecules [494]. If, for instance a mixture of different isotopomers of a molecular species (these are molecules with different atomic isotopes) is present, the absorption spectra of the different isotopomers might overlap which impedes the analysis of the spectrum. Therefore the separation of these isotopomers by a mass spectrometer will facilitate the unambiguous analysis. The isotope shift of spectral lines gives additional information on the molecular structure. 

In Vol. 1, Sect. 3.3. we discussed how elastic and inelastic collisions contribute to the broadening and shifts of spectral lines. In a semiclassical model of a collision between partners A and B, the particle B travels along a definite path r(t) in a coordinate system with its origin at the location of A. The path r t) is completely determined by the initial conditions r(0) and (dr/df)o and by the interaction potential V(r, Ex, E-b), which may depend on the internal energies Ex and b of the collision partners. In most models a spherically symmetric potential V r) is assumed, which may have a minimum at r = ro (Fig. 8.1). If the impact parameter b is large compared to tq the collision is classified as a soft collision, while for b hard collisions occur. 

An interesting application of frequency combs in astronomy allows the accurate determination of the Doppler-shift of spectral lines from stars due to their velocity relative to the earth. While former measurements had an uncertainty of An = 10 m/s the comb measurements could resolve velocity changes down to 10 cm/s [1338]. 

In Sect. 3.3. we discussed how elastic and inelastic collisions contribute to the broadening and shifts of spectral lines. In a semiclassical model of a collision between partners A and B, the particle B travels along a definite path r t) in a coordinate system with its origin at the location of A. The path r t) is... 

S.Yi Chen, M. Takeo Broadening and shift of spectral lines due to the presence of foreign gases. Rev. Mod. Phys. 29, 20 (1957)... 

The adiabatic theory enables quite accurate theoretical estimates of the broadening and shift of spectral lines to be made in simple cases. For interaction potentials of the form it predicts a unique ratio of linewidth to line... 

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