137 research outputs found
Optimal values of rovibronic energy levels for triplet electronic states of molecular deuterium
Optimal set of 1050 rovibronic energy levels for 35 triplet electronic states
of has been obtained by means of a statistical analysis of all available
wavenumbers of triplet-triplet rovibronic transitions studied in emission,
absorption, laser and anticrossing spectroscopic experiments of various
authors. We used a new method of the analysis (Lavrov, Ryazanov, JETP Letters,
2005), which does not need any \it a priory \rm assumptions concerning the
molecular structure being based on only two fundamental principles:
Rydberg-Ritz and maximum likelihood. The method provides the opportunity to
obtain the RMS estimates for uncertainties of the experimental wavenumbers
independent from those presented in original papers. 234 from 3822 published
wavenumber values were found to be spurious, while the remaining set of the
data may be divided into 20 subsets (samples) of uniformly precise data having
close to normal distributions of random errors within the samples. New
experimental wavenumber values of 125 questionable lines were obtained in the
present work. Optimal values of the rovibronic levels were obtained from the
experimental data set consisting of 3713 wavenumber values (3588 old and 125
new). The unknown shift between levels of ortho- and para- deuterium was found
by least squares analysis of the , ,
rovibronic levels with odd and even values of . All the energy levels were
obtained relative to the lowest vibro-rotational level (, ) of
the electronic state, and presented in tabular form together
with the standard deviations of the empirical determination. New energy level
values differ significantly from those available in literature.Comment: 46 pages, 9 picture
On the measurement of laser-induced plasma breakdown thresholds
The breakdown threshold of a gas exposed to intense laser-radiation is a function of gas and laser properties. Breakdown thresholds reported in the literature often vary greatly and these differences can partially be traced back to the method that is typically used to determine breakdown thresholds. This paper discusses the traditional method used to determine breakdown thresholds and the potential errors that can arise using this approach, and presents an alternative method which can yield more accurate data especially when determining breakdown thresholds as functions of gas pressure
Oscillator Strengths and Damping Constants for Atomic Lines in the J and H Bands
We have built a line list in the near-infrared J and H bands (1.00-1.34,
1.49-1.80 um) by gathering a series of laboratory and computed line lists.
Oscillator strengths and damping constants were computed or obtained by fitting
the solar spectrum.
The line list presented in this paper is, to our knowledge, the most complete
one now available, and supersedes previous lists.Comment: Accepted, Astrophysical Journal Supplement, tentatively scheduled for
the Sep. 1999 Vol. 124 #1 issue. Text and tables also available at
http://www.iagusp.usp.br/~jorge
Volatile and Organic Compositions of Sedimentary Rocks in Yellowknife Bay, Gale crater, Mars
HâO, COâ, SOâ, Oâ, Hâ, HâS, HCl, chlorinated hydrocarbons, NO and other trace gases were evolved during pyrolysis of two mudstone samples acquired by the Curiosity rover at Yellowknife Bay within Gale crater, Mars. HâO/OH-bearing phases included 2:1 phyllosilicate(s), bassanite, akaganeite, and amorphous materials. Thermal decomposition of carbonates and combustion of organic materials are candidate sources for the COâ. Concurrent evolution of Oâ and chlorinated hydrocarbons suggest the presence of oxychlorine phase(s). Sulfides are likely sources for S-bearing species. Higher abundances of chlorinated hydrocarbons in the mudstone compared with Rocknest windblown materials previously analyzed by Curiosity suggest that indigenous martian or meteoritic organic C sources may be preserved in the mudstone; however, the C source for the chlorinated hydrocarbons is not definitively of martian origin
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