Emissive-absorptive

To allow for the difference between emissivity and absorptivity and combine them into a single emissivity-absorptivity term called effec-... 

A. Sapinski, Arch Procesow Spalania 3 (2), 179-90 (1972) CA 78, 99929 (1973) Temp mesurement of a flame containing solid particles by the emission-absorption method The method was used for investigation of solid proplnts con-... 

A transition linearly coupled to the phonon field gradient will experience, from the perturbation theory perspective, a frequency shift and a drag force owing to phonon emission/absorption. Here we resort to the simplest way to model these effects by assuming that our degree of freedom behaves like a localized boson with frequency (s>i. The corresponding Hamiltonian reads... 

No emission/absorption of a photon in FRET spectroscopic transition dipoles... 

Greek pots and European bronzes - archaeological applications of emission/absorption spectrometries... 

Being related to a resonant behavior of the opacity for the extraordinary mode, the proton cyclotron line appears as an absorption feature in the spectrum. Atmospheres comprised of heavy elements (Fe) were studied by Rajagopal et al. (1997) the emergent spectra exhibit a variety of emission/absorption features produced by atomic transitions. Such models, however, suffer from our lack of knowledge of the ionization states and opacities of metals in a strong magnetic field. 

There are a variety of radiative transfer models for the atmosphere that incorporate all of the emission, absorption, and scattering processes as a function of altitude. These are used to predict the total radiance as... 

A recent development in physical techniques which may be of aid in evaluating the relative merits of theory is the Mossbauer effect. This effect is based upon recoilless y-ray emission (absorption) resulting from a nuclear transition in a particular atom with the resonance condition of zero-phonon processes. Since such nuclear transitions can be obtained with... 

It would appear in all cases that measurements should be based on atomic absorption instead of flame emission. Absorption spectra are simpler than emission spectra. In reality, however, the absorption measurements can be complicated by the presence of interferences, chemical interaction, instability of the energy level, and other phenomena that occur at elevated temperatures (Fig. 14.3). 

According to Eq. 3.5, yi may be considered the total absorption in the translational band. We, however, prefer to consider Mq the total intensity, Eq. 3.4 with n = 0, because the spectral function g(v) is more closely related to the emission (absorption) process than a(v). For rare gas mixtures, we have the relationships of Eqs. 3.7. In other words, yo may be considered a total intensity of the spectral function, g(v), and the ratio yi /yo is a mean width of the spectral function (in units of cm-1). Both moments increase with temperature as Table 3.1 shows. With increasing temperature closer encounters occur, which leads to increased induced dipole moments and thus greater intensities. 

Figure A1.10 The superposition of net enhanced absorption A) with multiplet emission-absorption ElA). The lowest level, jSaj8x, has the largest excess population and the highest, aAax, a smaller excess. The lines A2 and X2, appearing in absorption, are more intense than the lines Al5 X1( which are in emission. The overall spectrum shows net absorption. From S. H. Pine, J. Chetn. Educ., 49, 664 (1972). Reproduced by permission of the Division of Chemical Education.

In general, a thorough spectroscopic study, as routinely carried out in the group of Prof. Dr. Dirk M. Guldi by means of steady-state emission/absorption measurements and time-resolved techniques in numerous solvents, sheds light onto the photophysical processes following photoexcitation of these systems. Equally, a detailed description of the employed spectroscopic methods will be given in the next sections. 

Flame Atomic Emission /Absorption Spectrometry FAES has been applied in milk samples for the determination of the major elements K and Na [35, 36]. Other elements such as Sr can be also determined by FAES [37]. 

E/A, emission-absorption CIDNP net effect EPI, echo planar imaging EPR, electron paramagnetic resonance ESR, electron spin resonance (same as EPR) exp, exponentiation on the base e... 

The energies of the triplet states of sensitizers TX (ITX) and of Pis TPO (BAPO) are close to each other ( 260 kJ/mol), allowing for slightly exothermic or thermoneutral T-T energy transfer from sensitizer to PI. Direct photolysis of phosphine oxides results in a well-documented initial strong absorptive (A) pattern of ESR spectra (see Fig. 12.2). Sensitization by TX or ITX of the photolysis of phosphine oxides leads evidently to the same radicals, but an initial polarization pattern is quite different, namely, emission/absorption (E/A) pattern (see Fig. 12.3). 

A, E, A/E, E/A-absorptive, emissive, absorptive/emissive, emissive/absorptive pattern of CIDEP spectra, respectively MFE-magnetic filed effect (general)... 

A recent experiment in a laboratory MHD channel at Stanford ( ) has shown that, under MHD conditions (high potassium loading), the addition of phosphorus, even in amounts much greater than those found in coal, has a much smaller effect on electron concentration and conductivity than would be predicted by the above modeling. That experiment Involved simultaneous measurement of electron concentration by submillimeter interferometry, of positive ion concentration by a swept electric probe, and of plasma temperature by the emission-absorption (line-reversal) technique, made in an ethanol-fueled, potassium-seeded combustion plasma. 

Microspectrometry is an indispensable technique in criminalistic analyses, being a combination of optical microscopy and spectrometry. Microscopy creates, records and interprets magnified images, whereas spectrometry uses emission, absorption and reflection of radiant energy by matter to determine its structure, properties and composition. On the basis of the type of energy applied, microspectrometry can be divided into IR, visual and ultraviolet (UV-vis), and Raman microspectrometry. This group also includes X-ray microspectrometry, in which an electron microscope takes the place of an optical microscope. Infrared and Raman microspectrometry enable determination and comparison of the chemical composition of studied samples UV-vis microspectrometry serves to compare the colour of samples in an objective way that is independent of the observer and X-ray microspectrometry allows determination of the elemental composition. 

Since both phonon and emission absorption are possible when hv> Eg + Bp, the absorphon coefficient is then... 

Thus, the ratio of the P values of this case becomes as follows from the low field to high field + V3 +6 V2 +15 0 -15 -6 /2 --s/3. Because a positive P value means an emissive signal, the ratio of the CIDEP signals as follows -1 -3.46 -8.66 0 8.66 3.46 1. Here, a negative (positive) intensity means an emissive (absorptive) signal. 

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