Wavelengths, laser fluorescence

A number of investigations of the copper-group oxides and dioxygen complexes have been reported. The electronic spectra of CuO, AgO, and AuO were recorded in rare-gas matrices (9), and it was found that the three oxides could be formed effectively by cocondensation of the metal atoms with a dilute, oxygen matrix, followed by near-ultraviolet excitation. The effective wavelengths for CuO or AgO formation were X > 300 nm and for AuO was X > 200 nm. In addition, the laser fluorescence spectrum of CuO in solid Ar has been recorded (97). 

Fig. 6 (a) Schematic illustration of a flow cytometer used in a suspension array. The sample microspheres are hydrodynamically focused in a fluidic system and read-out by two laser beams. Laser 1 excites the encoding dyes and the fluorescence is detected at two wavelengths. Laser 2 is used to quantify the analyte, (b) Scheme of randomly ordered bead array concept. Beads are pooled and adsorbed into the etched wells of an optical fiber, (c) Scheme of randomly-ordered sedimentation array. A set of encoded microspheres is added to the analyte solution. Subsequent to binding of the analyte, microparticles sediment and assemble at the transparent bottom of a sample tube generating a randomly ordered array. This array is evaluated by microscope optics and a CCD-camera. Reproduced with permission from Refs. [85] and [101]. Copyright 1999, 2008 American Chemical Society... 

Raman scattering cross sections are small ( 10 cm ), thus fluorescence and luminescence can easily interfere with the data. This is particularly acute with surface carbon, which fluoresces strongly when the Raman is excited by visible wavelength lasers. In addition, catalyst... 

Curl et al. (255) have analyzed the fluorescence spectrum excited by the 4765 A Ar+ laser line. The A2A2 state produced must predissociate appreciably at this wavelength since fluorescence is very weak and some decomposition products are found. Since the photon energy used (2.601 eV) is higher than D0(OC1 — O) = 2.50 cV, dissociation is expected. 

Fig. 4.4 Schematic diagram of a typical arrangment for laser induced fluorescence measurements of lifetimes. A pulsed laser beam (or beams) passes through a heated glass cell containing alkali vapor and the time and wavelength resolved fluorescence is detected...

Table I. LASER FLUORESCENCE EXCITING AND DETECTING WAVELENGTHS...

The H + NO2 OH + NO reaction provides an excellent example of the use of laser fluorescence detection for the elucidation of the dynamics of a chemical reaction. This reaction is a protot5q)e example of a radical-radical reaction in that the reagents and products are all open-shell free radical species. Both the hydroxyl and nitric oxide products can be conveniently detected by electronic excitation in the UV at wavelengths near 226 and 308 nm, respectively. Atlases of rotational line positions for the lowest electronic band systems of these... 

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