Dependence on wavelength

This treatment assumes that a single complex is present, but this assumption may not be valid. When only one complex is present, the value of xm lx is independent of the wavelength at which the absorbance or fluorescence intensity is measured. A dependence on wavelength is an indication of the presence of more than one complex. 

Depending on their function, radiometers can be either thermal or photon detectors. In thermal detectors, the incident photon energy is converted into heat, which is then measured. The measured data are independent of wavelength. Photon detectors are based on photoelectric effect and measure spectrum intensity. The results are dependent on wavelength. 

Photon detectors are based on photoelectric effect and measure spectrum intensity. The results are dependent on wavelength. 

Pigments become transparent in binders when the difference between the refractive index of the pigment (which depends on wavelength) and that of the binder is low, and when the particle size of the pigment is in the range 2-15 nm. The decisive factor for transparency is, however, the thickness of the pigment particles in the direction in which the light travels. 

For higher concentrations, we need all the terms in Equation 18-12. As concentration increases, a peak emission is reached. Then emission decreases because absorption increases more rapidly than the emission. We say the emission is quenched (decreased) by self-absorption, which is the absorption of excitation or emission energy by analyte molecules in the solution. At high concentration, even the shape of the emission spectrum can change, because absorption and emission both depend on wavelength. 

Thus various lines of evidence lead to the conclusion that there is a process which is of varying importance dependent on wavelength and probably on other conditions which destroy the singlet or the triplet state, or both. Since the extent of this process depends on wavelength one must conclude that the rate of crossover depends on the vibrational level of the upper electronic state. 

Phase Index of Refraction. Phase index of refraction is the ratio of the phase velocity of light in a vacuum to its velocity in another medium, such as glass. The value of this parameter depends on wavelength, and the composition, temperature and pressure of the medium. The higher the re aclive index of a material, the lower the phase velocity of light in the material, and the more a light ray is bent as it enters the. material from air. 

PPX-composite films containing semiconductor nanocrystals of PbO (formed by oxidation of Pb nanocrystals) and PbS show photoconductivity [71, 89]. In the PbO-PPX films the photocurrent value (/ph) in the wavelength range 250-350 nm does not depend on wavelength and the ratio between 7ph and dark current is close to 104. Then /ph is gradually reduced to zero at increase of wavelength to 450 nm [89],... 

The amplitude of the composite wave is no longer a periodic function because of the factor defined by the second cosine term. The total wave packet moves along without change in shape providing the component waves have the same velocity. The only instance where this is known to apply is for electromagnetic photons in vacuum. In all other cases, for instance electrons, the velocity depends on wavelength (and k). 

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