Calcium line spectrum

Figure 3.5 Doppler effect with calcium source, indicated by 4. The calcium line in the spectrum at top is redshifted in the bottom spectrum because the source is moving away from Mr. Plex. For stars moving tens of thousands of miles per second away from us, the redshift can be quite pronounced.

In calcium chelators Indo-1 (17) and Fura-3 (18b) (Figure 2.9),(18) the fluoropho-res have donor-acceptor stilbene-like structures rigidified so as to avoid photoisomerization. Based on the same principle, Fura-2 (18a)a8) is one of the most popular calcium indicator for microscopy of individual cells because, in contrast to Quin-2 (see Section 2.2.5.), the excitation spectrum is blue shifted on cation binding, thus allowing intensity-ratio measurements. On the other hand, there is almost no shift of the emission spectrum, which can be interpreted along the same line as DCM-crown (see earlier in this section). 

The plasmodia of the wild type of Physarum polycephalum are bright yellow and produce an orange-red pigment that is also present in a white mutant [120]. This compound, named physarorubinic acid (64), binds calcium and other metals very well and this made acquisition of the H-NMR spectrum difficult (line broadening) unless the sample was washed with aq. EDTA solution. The structure contains a decapentaene system and signals at 5 102.4 (C-3), 172.6 (C-7), 174.5 (C-2) and 194.0 (C-4) are characteristic of C-3 acylated tetramic acid unit. 

The transport of protons from HTD surface on Ca(OH)2 surface is accompanied by redistribution of electron densities on neighboring calcium and titanium atoms [50]. According to XPS (Fig. 6.12), the binding energy of the Ti 2p3/2 level in the initial HTD is weakly sensitive to the presence of OH" groups and H2O it is quite the same for HTD and anhydrous anatase [51]. In the activated HTD, the position of the maximum ofTi 2p3/2 line is not changed but broadening of the line occurs that is connected with the formation of defects on the surface. However, in the spectrum of activated... 

FIGURE 5. The absorption spectrum of MDH lacking calcium (broken line), isolated from mxaA mutant, and the effect of incorporation of calcium into the enzyme (solid line). Reproduced with permission from Goodwin et al. (1996), Biochemical Journal, 319, 839n842). the Biochemical Society. 

Fig. 1. Spectral scan of the emission of calcium hollow cathode tube (Ransley Glass, Melbourne, Australia). The emission spectrum is dominated by the strong resonance line of calcium at 4227 A (reproduced from reference (Z3) by permission from the editor of Clinical Chemistry).

Figure 7 shows the relative increase in sideband intensities for CP over BD as HPO4" and CO3" ions are introduced into the lattice and the considerable broadening of the CHA-B peaks [42]. The effect of HPO " ions is obvious, since they give pronounced sideband patterns and cross-polarize very efficiently. This has already been explained during the discussion of BRU. Figure 8 proves that the appearance of sideband patterns is very sensitive to the structure of the material [20]. It was found [42] that decrease in crystallinity results in considerable increase of linewidths and sideband intensities, and in dramatic reduction or disappearance of DD peaks (Fig. 9) [42]. The centreband in the CP spectrum of poorly crystalline HA looked like a superposition of a sharp line on a broader background. The CP and BD spectra of amorphous calcium phosphate were virtually identical within the experimental error. Aue et al. [42] admitted that they found no satisfactory explanation for the latter observation. Likewise, the discussion of the CO3" effect (Fig. 7) did not go very far. It was stated that the CHA-B lines were 5-10 times broader than those from various HA samples and that this broadening showed rather small dependence on carbonate concentration. It was inferred that the introduction of CO3" increased the CP efficiency of some PO " ions in the crystal lattice and imparted some changes in the PO " shift anisotropies. The former is questionable, because no protons were introduced into intracrystalline sites proximate to PO ions and the latter acceptable, because the CHA lattice must be less ordered, at least in the...

Line spectra occur when the radiating species are individual atomic particles that are well separated, as in a gas. The individual particles in a gaseous medium behave independently of one another, and the spectrum in most media consists of a series of sharp fines with widths of 10 to 10 - A (10 to 10 nm). In Figure 24-19, fines for sodium, potassium, strontium, calcium, and magnesium are identified. 

Both atomic and molecular emission and absoiption can be measured when a sample is atomized in a flame. A typical flame-emission spectrum was shown in Figure 24-19. Atomic emissions in this spectrum are made up of narrow lines, such as that for sodium at about 330 nm, potassium at approximately 404 nm, and calcium at 423 nm. Atomic spectra are thus called line spectra. Also present are emission bands that result from excitation of molecular species such as MgOH, MgO, CaOH, and OH. Here, vibrational transitions superimposed on electronic transitions produce... 

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