Analysis of the high resolution spectrum of the ν2 and ν5 absorption bands of methyl chloride

1984 ◽  
Vol 62 (3) ◽  
pp. 247-253 ◽  
Author(s):  
M. Morillon-Chapey ◽  
G. Guelachvili ◽  
Per Jensen
Keyword(s):  
Standard Deviation ◽  
High Resolution ◽  
Infrared Spectrum ◽  
Least Squares ◽  
Methyl Chloride ◽  
High Resolution Spectrum ◽  
Vibrational States ◽  
Absorption Bands ◽  
Least Squares Fit

The infrared spectrum of methyl chloride CH3Cl between 1280 and 1650 cm−1 has been recorded at high resolution (0.005 cm−1). The Coriolis interactions between ν2(A1) and ν5(E) and between 2ν3(A1) and ν5 have been investigated through a least squares fit to the transitions observed for CH335Cl. Ten parameters for the three upper vibrational states and three interaction constants have been determined, reproducing the 1200 observed wavenumbers with a standard deviation of 0.002 cm−1. An accidental resonance of the type l(ΔK = 2, Δl = −1) between ν2 and ν5 was found to be present in the spectrum.

Étude des bandes infrarouges en résonance 2ν2, ν2 + ν5, , , 2ν3 + ν5 et 4ν3 du chlorure de méthyle

1982 ◽  
Vol 60 (6) ◽  
pp. 825-843 ◽  
Author(s):  
Najath Binsari-Zizi ◽  
Claude Alamichel ◽  
Guy Guelachvili
Keyword(s):  
Fourier Transform ◽  
Standard Deviation ◽  
High Resolution ◽  
Least Squares ◽  
Methyl Chloride ◽  
Coupling Model ◽  
Fermi Resonance ◽  
Simplified Model ◽  
Interaction Scheme ◽  
Very High

The spectrum of methyl chloride has been analyzed between 2650 and 2950 cm−1 from Fourier transform recordings obtained with a very high resolution. More than 3000 lines of CH335Cl and more than 1500 lines of CH337Cl, most of them belonging to ν2 + ν5 and [Formula: see text], have been assigned: the 2ν2, [Formula: see text], 4ν3 and 2ν3 + ν5 bands are very weak and only appear when there are level crossings. The main interaction is the Coriolis resonance between the ν2 and ν5 modes, which links the rovibrational levels six by six. The Fermi resonance between [Formula: see text] and ν1, whose existence has just been shown, does not seem to have important consequences. Numerous other resonances, particularly making the 4ν3 and 2ν3 + ν5 bands visible, must be added to the basic coupling model; they make the general interaction scheme extremely complex. A least squares calculation, according to a simplified model, has given a standard deviation of 0.029 cm−1 over 784 lines of CH337Cl, from which crossings and locally perturbed subbands were excluded.

A Wind Wave Co-Cumulative Spectral Model

1970 ◽  
Vol 14 (04) ◽  
pp. 277-295
Author(s):  
Carl F. Kottler
Keyword(s):  
Standard Deviation ◽  
Least Squares ◽  
Wind Velocity ◽  
Wind Wave ◽  
Surface Wind ◽  
Systematic Investigation ◽  
Spectral Model ◽  
Least Squares Fit ◽  
Wind Sea ◽  
Cumulative Model

A systematic investigation was made of the parameters chosen to define the Pierson-Moskowitz wind sea spectral model. The model was generalized and the form was extended to give a better fit of the data. Using the same sets of data as those selected by Pierson and Moskowitz for building their model, a least-squares fit of each set of the co-cumulative data gave a corresponding optimum set of parameters. These unique optimum sets of parameters yielded an eightfold decrease in the standard deviation. From this family of parameter sets, a co-cumulative spectral model was. developed to fix some of the parameters and relate the others to surface wind velocity. This modification and extension show that at least a twofold improvement in accuracy over the associated Pierson-Moskowitz co-cumulative model can be achieved.

High-Resolution Infrared Spectrum of Diazirine, H2CN2. Rovibrational Analysis of the Methylene Deformation Band

1988 ◽  
Vol 43 (4) ◽  
pp. 331-337 ◽  
Author(s):  
A. Gambi ◽  
A. Baldacci ◽  
S. Giorgianni
Keyword(s):  
Fourier Transform ◽  
High Resolution ◽  
Infrared Spectrum ◽  
Least Squares ◽  
Deformation Band ◽  
Fourier Transform Spectrometer ◽  
Centrifugal Distortion ◽  
Molecular Constants ◽  
Centrifugal Distortion Constants

Abstract The infrared spectrum of diazirine has been recorded at Doppler resolution with a high informa­tion Fourier transform spectrometer. The ν3 fundamental has been reinvestigated and the overall assignment of the rovibrational transitions has been carried out. From the least-squares analysis a more accurate set of molecular constants including the sextic centrifugal distortion constants has been determined for the level υ3 = 1 and will be reported here. The higher resolution achieved here allowed the assignment of weaker lines and many Q branch transitions. Moreover many blended lines have now been resolved and could be properly assigned.

The high-resolution infrared spectrum of BrCl

1994 ◽  
Vol 72 (11-12) ◽  
pp. 1145-1154 ◽  
Author(s):  
Hiromichi Uehara ◽  
Toichi Konno ◽  
Yasushi Ozaki ◽  
Koui Horiai ◽  
Kuniaki Nakagawa ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Standard Deviation ◽  
High Resolution ◽  
Infrared Spectrum ◽  
Potential Function ◽  
Internuclear Distance ◽  
Spectral Lines ◽  
Fourier Transform Spectrometer ◽  
Isotopic Species ◽  
Correction Terms

The high-resolution infrared spectrum of BrCl has been observed with a Fourier transform spectrometer. About 850 spectral lines for the Δν = 1 sequences of the four isotopic species, 79Br35Cl, 81Br35Cl, 79Br37Cl, and 81Br37Cl have been measured between 417 and 461 cm−1. They have been fitted with a standard deviation of 0.000 146 cm−1 to a Dunham potential function using eight coefficients that included two Watson-type Δ correction terms. Dunham Yij coefficients have been derived for each of the four isotopic species. The equilibrium internuclear distance re of BrCl is 2.136 053 28 (67) Å.

scholarly journals Cumulative Gaussian Curve Fitter for Boundary Parameterization

2005 ◽  
Author(s):  
David Wang ◽  
Robert Tamburo ◽  
George Stetten
Keyword(s):  
Standard Deviation ◽  
Least Squares ◽  
Rapid Method ◽  
Finite Sample ◽  
Pixel Resolution ◽  
First Derivative ◽  
Gaussian Curve ◽  
Least Squares Fit ◽  
Boundary Location ◽  
Boundary Width

We have previously developed an algorithm for locating boundaries in an image with sub-pixel resolution, as well as estimating boundary width and image intensity within the adjoining objects. The algorithm operates by finding the parameters of a cumulative Gaussian curve that best approximates an intensity profile taken across a boundary. If intensity is sampled along the image gradient across a boundary, it is reasonable to assume the profile approximates a finite portion of a cumulative Gaussian. Given that assumption, the first derivative of the profile should be the corresponding portion of a Gaussian, completely described by its mean, standard deviation, and amplitude. We present here a simple and rapid method to find those parameters, given that we only have a potentially skewed sample of the Gaussian. The parameters are approximated first for the finite sample, and then both ends of the Gaussian are extrapolated using the resulting parameters. New parameters are then calculated and the procedure is repeated. The optimization rapidly converges, yielding boundary location (mean) with sub-pixel accuracy as well boundary width (standard deviation). Integration then reproduces the cumulative Gaussian, and a least-squares fit is applied to estimate the constant of integration, from which intensity of the adjoining regions can be estimated.

scholarly journals The Wilson-Bappu Effect for MG II K-Line Emission Widths

1985 ◽  
Vol 111 ◽  
pp. 381-383
Author(s):  
M. Parthasarathy
Keyword(s):  
High Resolution ◽  
Least Squares ◽  
Linear Correlation ◽  
Line Emission ◽  
Absolute Magnitude ◽  
Late Type ◽  
Least Squares Fit ◽  
Image Position

The existence of a tight linear correlation between the stellar absolute magnitude Mv and the Mg II k-line emission width log WMg II k (kms−1) is confirmed using IUE high-resolution (0.2A) data for 100 late-type stars. A least-squares fit to the data gives the relation:

Calculated energy levels and intensities for the ν1 + ν2 and 3ν2 bands of HDO

1986 ◽  
Vol 64 (6) ◽  
pp. 736-742 ◽  
Author(s):  
A. Perrin ◽  
C. Camy-Peyret ◽  
J. -M. Flaud
Keyword(s):  
Least Squares ◽  
Strong Influence ◽  
Energy Levels ◽  
Rotational Energy ◽  
Transition Moment ◽  
Synthetic Spectrum ◽  
Vibrational States ◽  
Line Intensities ◽  
Least Squares Fit ◽  
Line Positions

A Hamiltonian taking into account both Fermi- and Coriolis-type interactions has been used to reproduce very satisfactorily the available rotational energy levels of the (1 1 0) and (0 3 0) interacting vibrational states of HDO. Then, a least squares fit of the line intensities of the ν1 + ν2 and 3ν2 bands of HDO has provided us with the transformed transition-moment operators of these two bands expanded in a form adapted to the Cs symmetry type of the molecule. The strong influence of the resonances on both line positions and intensities has been exemplified. Finally, the synthetic spectrum of the ν1 + ν2 and 3ν2 hybrid bands of HDO has been computed.

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