Ultraviolet light vacuum

Biological sources account for the overwhelming fraction of O2 found in the present atmosphere. Considerable controversy and no small degree of uncertainty surrounds the mechanism of oxygen formation in the pre-biological atmosphere (Levine et al., 1981 Levine, 1982). The attractive suggestion that the photodecomposition of H2O by vacuum ultraviolet light in... 

When a solvated anion Br j j, is irradiated at the solution surface by a vacuum-ultraviolet light, it is photoionized if tne photon energy hv exceeds the minimum energy hv, or , necessary for the following reaction, hv. ... 

Where nanoscale dimensions are involved, this necessitates the use of vacuum ultraviolet light or x rays. Penetration of the x rays into the semiconductor must be avoided to prevent damage to the crystal, so wavelengths of 1.3 nm or 4.5 nm are preferred because the polymeric resist exhibits an absorption depth of about 1 micron at these wavelengths. 

Hozumi, A., Yokogawa, Y., Kameyama, T., Hiraku, K., Sugimura, H., Takai, M., and Okido, M. 2000. Photocalcination of mesoporous silica films using vacuum ultraviolet light. Advanced Materials 12, 985-987. 

Sugimura H, Ushiyama K, Hozumi A, Takai O (2000) Micropatteming of alkyl- and fluoro-alkylsilane self-assembled monolayers using vacuum ultraviolet light. Langmuir 16 885-888... 

There are several possible explanations which need to be considered for the formation of N2 in the photolysis of cyclohexane-nitrous oxide solutions. These include direct absorption of vacuum ultraviolet light by nitrous oxide, photoionization of the solvent followed by electron attachment by nitrous oxide, and reaction of nitrous oxide with either excited cyclohexene or excited cyclohexane molecules. Of these possibilities only the last explanation—reaction of excited cyclohexane molecules with nitrous oxide—is important. 

Many of the photochemical advances that have occurred during the past two decades have followed from the development of microwave discharge vacuum ultraviolet light sources, emitting either intense monochromatic atomic resonance radiation at fixed wavelengths (determined by nature rather than for utility) or over broad continua produced by the fluorescent decay of rare gas excimers which provide tunable sources after passage through a vacuum monochromator (but at the cost of reduced intensity). 

Plasma, also called the fourth state of matter, is a partially or fully ionized gas containing electrons, ions and neutral atoms or molecules, where the atoms have so much kinetic energy that the valence electrons are freed by atomic-level colhsions [51]. Peebles [52] describes a plasma gas as containing a few parts per million of ions, 2 20% free radicals and a large amount of extremely energetic vacuum-ultraviolet light. 

The effects observed in surface treatment of polymers are caused by the chemical energy of free radicals or ions (if there is a bias voltage on the parts) or by the photochemical energy of the ultraviolet light. The plasma gas contains a few parts per million of ions [2], a few percent (2% to 20%) of free radicals [3], and a large amoimt of extremely energetic vacuum-ultraviolet light (VUV). 

Carter KE, Farrell J (2008) Oxidative destruction of perfluorooctane sulfonate using boron-doped diamond film electrodes. Environ Sci Technol 42(16) 6111-6115 Chen J, Zhang PY et al (2007) Photodegradation of perfluorooctanoic acid by 185 nm vacuum ultraviolet light. J Environ Sci 19(4) 387-390... 

The quantity k r is equivalent to k r cos 0 = 27r r cos d/X, where 6 is the angle formed between the vectors k and r. The matrix elements ( m W t) k limit r to the molecular dimensions over which the wave functions k and molecular spectroscopy are on the order of 10 A for vacuum-ultraviolet light, and are of course much longer for visible, IR, and microwave spectroscopy. Hence k r is typically much less than 1, and the series expansion of exp(ik r) converges rapidly. In the special geometry we have assumed for our vector potential,... 

Illumination of the pure liquid by photons of sufficient energy creates electrons and positive ions. The photon energy hv has to be greater than ihe band gap of the liquid, Ijiq, which usually requires vacuum ultraviolet light. Since this light is strongly... 

Bottcher, E. H. and Schmidt, W. E, Photoconductivity of nonpolar liquids induced by vacuum-ultraviolet light, /. Chem. Phys., 80,1353,1984. 

From the photoconductivity induced by vacuum ultraviolet light, the band gap. Eg, of several simple polymers was determined. The data are summarized in Table 7. 

Kitani, L, Nojima, K., Yoshino, K., Inuishi, Y., and Kawatsu, M., Temperature dependence of photoconduction in polyethylene induced by vacuum-ultraviolet light,/pn. /. Appl. Phys., 21, 363, 1982. 

Cui, W., Thompson, M. S., Reilly, ]. P. (2005). Pathways of peptide ion fragmentation induced by vacuum ultraviolet light. Journal of The American Society for Mass Spectrometry, 15(8), 1384-1398. 

Devakumar, a. TIiompson, M. S. Reilly, J. P. Fragmentation of oligosaccharide ions with 157 nm vacuum ultraviolet light. Rapid Common. Mass Spectrom. 2005, 19, 2313-2320. 

Yuan, H. Killelea, D. R. Tepavcevic, S. Kelber, S. I. and Sibener, S. J., interfa-cial chemistry of poly(methyl methacrylate) arising from exposure to vacuum-ultraviolet light and atomic oxygen, J. Phys. Chem. A, 115, TI i6- nA5 (2011) D01.org/10.1021/jpl061368. 

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