Lasers liquids

FBAs are used to brighten not only textile materials but also paper, leather and plastics. They are important constituents of household detergent formulations. More specialised areas of application include lasers, liquid crystals and biological stains. By far the most important uses for FBAs, however, are in applications to textiles and paper. Much of what follows will be concerned with these two categories. 

The thermal decomposition of 8 in tetrachloroethene at 134 C gave a chromatographically separable mixture of cyclobutane 9 and 1,8-divinylnaphthalene 10 in 7 1 ratio. Although several experiments have been carried out to identify the spin multiplicity of the intermediate diradical, the results were inconclusive.17 A recent report stated that while triplet-sensitized photolysis resulted in predominant denitrogenation, laser/liquid jet photochemical reaction also gave cyclopentenes by 1,2-hydrogen shift.18 Indications are that the amounts of cyclopentenes increase with increasing lifetime of the intermediary 1,3-cyclopentadiyl triplet diradical.18... 

The laser liquids prepared by these techniques possess properties, such as high gain and sharpness of the emission, that are more characteristic of crystalline hosts (Nd3+ CaWC>4 or Nd3+ YAG) than glass lasers (Heller, 1966 Heller, 1968a Lempicki and Heller, 1966). Moreover, under identical excitation conditions, the solutions have 4F3/2 -> 4In/2 emission... 

Use (Gas) Luminescent electric tubes and photoelectric bulbs, electronic industry, high-voltage indicators, lasers. (Liquid) cryogenic research. 

The benzophenone sensitized photodenitrogenation of 2,3-diazabicyclo[2.2.1]alkanes 1 has been achieved using the laser/liquid jet technique with a CW argon ion laser. 

Benzophenone sensitized laser/liquid jet photochemistry generated electronically excited cyclopentadiyl species by two-photon processes. The first photon is required to generate the ground state cyclopentadiyl triplet diradical by benzophenone sensitized denitrogenation of the diazoalkane, the second one to produce the excited cyclopentadiyl and subsequent photo-... 

Cyclopropane derivatives are the major products of photoelimination of nitrogen from 1-pyrazolines. Conversion of the fused pyrazoline (10) into the cyclopropane (11) was achieved in this way in 85% yield by irradiation in the presence of acetophenone and constitutes a valuable step in a synthesis of a diquinane alcohol. The short-lived triplet 1,3-cyclopentadiyl biradical, generated by benzophenone-sensitised irradiation of diazabicyclo-(2.2.1]hept-2-ene, has been trapped as a Jbis-alkoxyamine by a nitroxide. The diazabicycloheptenes (12) gave in a similar fashion the bicydo[2.1.0]pentanes (13) on triplet-sensitised photolysis, whereas laser/liquid jet excitation of the same compounds gave in addition the cyclopentenes (14), derived by 1,2-hydrogen shift evidence for a two-photon process is described. The results of a time-resolved spectroscopic study of the photodecomposition of 2,3-diazabicyclo[2.2.l]hept-2-ene in the vapour phase have also been reported.Photolysis of 2,3-diaza-5-methylenebicyclo[2.2.l]hept-2-ene affords the semi-localised... 

Study of Laser Liquid Organic Compound Interactions. A Particular Case Laser- vinylacetate Interaction. A New Phenomenon Multiphoton Absorption. Laserolysis... 

The spectroscopic properties and chemistry of aprotic Nd + laser liquids plus references to earlier studies are discussed by Brecher and French (V7). The oscillator strengths and fluorescence lifetimes are comparable to those in solids with quantum efficiencies near unity. Since fluorescence line-widths are smaller than in glasses, the stimulated emission cross sections are larger (1 8), although still less than in crystals. Aprotic liquid laser materials and references are listed in Ref. 19. Thus far only Nd3+ has been used as the laser ion although other lanthanide ions could also be used. 

Hartge et al. fast fluidized bed quartz sand probe I probe II 25 mW HcNc laser liquid-solid bed... 

R. Subrcuncmian, P. E. Denney, J. Singh, M. Otooni, A Novel Technique for Synthesis of Silver Nanoparticles by Laser-Liquid Interaction. Journal of Materials Science 1998,33,3471-3477. 

We would like to note that the designing of tunable diode lasers is one of the most promising approaches used for the development of gas analyzers aimed for detection of a spedlic gas (Somesfalean et al. 2005). Gas analyzers based on tunable diode lasers are considerably simpler in comparison with conventional systems. A tunable laser is a laser whose wavelength of operation can be altered in a controlled manner. There are many types and categories of tunable lasers. They exist in the gas, liquid, and solid slates. Among the types of tunable lasers are excimer lasers, COj lasers, dye lasers (liquid and solid slate), transition-metal solid-state lasers, semiconductor crystal and diode lasers, and free-electron lasers (Duarte 1995). 

In some absorbing (at the 5145 A line of an Ar laser) liquid crystals [4-4 -bis(heptyloxy )azoxybertzene], a study ° has shown peculiar polarization dependences on the optical fields. These effects are undoubtedly related to the electronic stmctures of these liquid crystals and their changes following photoabsorption, but the exact mechanisms remain to be ascertained. 

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