Combination reactions radiative

Several studies have examined the reactions of Mg+" with unsaturated molecules. Under the lower pressure conditions of FT-ICR mass spectrometry, Mg+" reacts with the polycyclic aromatic hydrocarbon, coronene, via a combination of radiative associative adduct formation (equation 16) and electron transfer (equation 17). The latter reaction is 8 times faster, consistent with it being exothermic. Adduct formation (equation 16) also readily occurs in reactions with Theoretical calculations suggest that related radiative... 

The emission spectrum consists of a series of weak bands starting at about 220 nm and then growing into a continuum from about 240 to 400 nm, with a maximum at approximately 270 nm as shown in Figure 5. Halstead and Thrush estimated that =65% of the emission occurs from the B2 state, =15% from the 3B3, and =20% from a combination of the A2 and Bi states [24, 28, 29] with a rate constant of 2 X 1CT31 cm6 molec 2 s 1 using argon as the bath gas at 300 K [53], As with the reaction of SO + 03 discussed above, collisional coupling results in a radiative lifetime that is pressure dependent. 

The pK of tyrosine explains the absence of measurable excited-state proton transfer in water. The pK is the negative logarithm of the ratio of the deprotonation and the bimolecular reprotonation rates. Since reprotonation is diffusion-controlled, this rate will be the same for tyrosine and 2-naphthol. The difference of nearly two in their respective pK values means that the excited-state deprotonation rate of tyrosine is nearly two orders of magnitude slower than that of 2-naphthol.(26) This means that the rate of excited-state proton transfer by tyrosine to water is on the order of 105s 1. With a fluorescence lifetime near 3 ns for tyrosine, the combined rates for radiative and nonradiative processes approach 109s-1. Thus, the proton transfer reaction is too slow to compete effectively with the other deactivation pathways. 

Reduced availability of SO2 would reduce the formation rate of new particles. Further studies are needed to elucidate the combined effect of these reactions of cloud microphysics and radiative forcing. Regions that cloud be affected most by these changes are the large regions of marine stratocumuli, especially the tradewind systems. 

The intermolecular reaction of BPHhDj) with the solvent molecules and the unimolecular cleavage of the O—H ketyl bond of BOH-GT) yielding BP and a hydrogen atom have been observed in the microsecond time scale [112-114]. Thus, the decay of BPH Di) can be attributed to the combination of a chemical reaction and nonradiative and radiative transition processes... 

A numerical model of a PDR has at least to combine radiative transfer, chemical kinetics and thermal balance. This means that the generalized radiative transfer equation 10.17) and the thermal balance equation (ID. 10) have to be solved self-consistently witli the rate equations describing the chemical reactions. Due to the very low densities prevailing in the interstellar mediimi only two-body interactions have to be accounted for. So the chemical rate system can be described by the following. set of equations ... 

Thermite itself (Formula 198) causes an extremely high heat concentration and is able to penetrate metal by means of one of its two reactions product, iron, in molten state high above its melting point at approximately 2500" C. Under some conditions, solid steel plates as thick as one inch can be perforated by a properly directed stream of the white-hot mass. While thermite can act as an incendiary because of its combination of convective or conductive and radiative heat, it is more valuable because of these penetrating properties, such as for demolition of machinery, Small amounts are too easily quenched to exert the proper persistent heat flow necessary for ignition of combustible structures. 

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