scholarly journals Line Intensity Measurements of the ν7+ν8 Band of Ethylene (12C2H4)

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
G. B. Lebron ◽  
T. L. Tan

From the four high-resolution FTIR absorbance spectra recorded at a spectral resolution of 0.0063 cm−1, 123 line intensities belonging to the ν7+ν8 band of 12C2H4 were measured and fit. The upper v7+v8=1 state rovibrational constants up to sextic terms determined using a Watson's A-reduced Hamiltonian model in Ir representation were used to calculate the line intensities of the band. Results of the experimental fit of the line intensities agree well with those obtained by calculations.

1974 ◽  
Vol 52 (9) ◽  
pp. 786-794 ◽  
Author(s):  
K-H. Tan ◽  
F. G. Donaldson ◽  
J. W. McConkey

Polarization free measurements are presented of the excitation of the 3s3p62S and 3s23p44s2P levels of Ar+ by electron impact. Line intensity measurements yielded relative transition probabilities in good agreement with the recent calculations of Luyken. A double peaked structure is demonstrated to be a common feature of the excitation functions and reasons for this are discussed. Cascade is shown to be an important excitation process for the 4s levels. Comparison is made with other work where available. As a means of calibration of some of the Ar line intensities, a careful measurement was made of the 736 Å Ne excitation function using the Bethe normalization procedure and the known optical oscillator strength.


1983 ◽  
Author(s):  
Max Loewenstein ◽  
James R. Podolske ◽  
Prasad Varanasi

Author(s):  
C. C. Ahn ◽  
D. H. Pearson ◽  
P. Rez ◽  
B. Fultz

Previous experimental measurements of the total white line intensities from L2,3 energy loss spectra of 3d transition metals reported a linear dependence of the white line intensity on 3d occupancy. These results are inconsistent, however, with behavior inferred from relativistic one electron Dirac-Fock calculations, which show an initial increase followed by a decrease of total white line intensity across the 3d series. This inconsistency with experimental data is especially puzzling in light of work by Thole, et al., which successfully calculates x-ray absorption spectra of the lanthanide M4,5 white lines by employing a less rigorous Hartree-Fock calculation with relativistic corrections based on the work of Cowan. When restricted to transitions allowed by dipole selection rules, the calculated spectra of the lanthanide M4,5 white lines show a decreasing intensity as a function of Z that was consistent with the available experimental data.Here we report the results of Dirac-Fock calculations of the L2,3 white lines of the 3d and 4d elements, and compare the results to the experimental work of Pearson et al. In a previous study, similar calculations helped to account for the non-statistical behavior of L3/L2 ratios of the 3d metals. We assumed that all metals had a single 4s electron. Because these calculations provide absolute transition probabilities, to compare the calculated white line intensities to the experimental data, we normalized the calculated intensities to the intensity of the continuum above the L3 edges. The continuum intensity was obtained by Hartree-Slater calculations, and the normalization factor for the white line intensities was the integrated intensity in an energy window of fixed width and position above the L3 edge of each element.


Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 323
Author(s):  
Zhiwei Feng ◽  
Guo Xia ◽  
Rongsheng Lu ◽  
Xiaobo Cai ◽  
Hao Cui ◽  
...  

A unique method to design a high-throughput and high-resolution ultrathin Czerny–Turner (UTCT) spectrometer is proposed. This paper reveals an infrequent design process of spectrometers based on Coddington’s equations, which will lead us to develop a high-performance spectrometer from scratch. The spectrometer is composed of cylindrical elements except a planar grating. In the simulation design, spot radius is sub-pixel size, which means that almost all of the energy is collected by the detector. The spectral resolution is 0.4 nm at central wavelength and 0.75 nm at edge wavelength when the width of slit is chosen to be 25 μm and the groove density is 900 lines/mm.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hua-Tian Tu ◽  
An-Qing Jiang ◽  
Jian-Ke Chen ◽  
Wei-Jie Lu ◽  
Kai-Yan Zang ◽  
...  

AbstractUnlike the single grating Czerny–Turner configuration spectrometers, a super-high spectral resolution optical spectrometer with zero coma aberration is first experimentally demonstrated by using a compound integrated diffraction grating module consisting of 44 high dispersion sub-gratings and a two-dimensional backside-illuminated charge-coupled device array photodetector. The demonstrated super-high resolution spectrometer gives 0.005 nm (5 pm) spectral resolution in ultra-violet range and 0.01 nm spectral resolution in the visible range, as well as a uniform efficiency of diffraction in a broad 200 nm to 1000 nm wavelength region. Our new zero-off-axis spectrometer configuration has the unique merit that enables it to be used for a wide range of spectral sensing and measurement applications.


2018 ◽  
Vol 3 (7) ◽  
pp. 171-178
Author(s):  
Arnis Asmat ◽  
Zamzami S.Z ◽  
Mansor S

The paper presents preliminary results of legal and illegal settlement extraction in Pulau Gaya, Sabah using high resolution Quickbird and SPOT- 5 multi-spectral imageries using automated house detection technique. The technique developed is spatial-based using tree counting approach. From the results, edge to edge of the house features was found precisely separated and can be delineated between houses that less than 2m distance. Results show that the technique able to delineate legal houses from Quickbird image more than SPOT-5. Differs results would be due to different spatial and spectral resolution of images. Keywords: Quickbird, SPOT, spatial filter, tree counting eISSN 2514-751X © 2018. The Authors. Published for AMER ABRA cE-Bs by e-International Publishing House, Ltd., UK. This is an open-access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer–review under responsibility of AMER (Association of Malaysian Environment-Behaviour Researchers), ABRA (Association of Behavioural Researchers on Asians) and cE-Bs (Centre for Environment-Behaviour Studies), Faculty of Architecture, Planning & Surveying, Universiti Teknologi MARA, Malaysia.


2020 ◽  
Author(s):  
Jean-Yves Chaufray ◽  
Majd Mayyasi ◽  
Michael Chaffin ◽  
Justin Deighan ◽  
Dolon Bhattacharyya ◽  
...  

<p>The recent observations performed with the high-resolution “echelle mode” by the Imaging Ultraviolet Spectrograph (IUVS) aboard the Mars Atmosphere and Volatile EvolutioN (MAVEN) mission indicated large deuterium brightness near Ls=270°. The deuterium brightness observed at the beginning of the mission, when Mars was close to its perihelion show brightness ~ 1 kR much larger than the first deuterium detection from Earth ~ 20-50R in 20-21 January 1997 (Ls = 67°). This low brightness of the deuterium emission is consistent with the lack of deuterium observation with the echelle mode of IUVS at solar longitudes around aphelion (Ls = 71°). During southern summer (Ls = 270°), especially near the terminator, the Lyman-α emission observed at 121.6 nm with the “low resolution mode” presents some vertical profiles that were not reproducible with models including only the emission from the thermal hydrogen population. In this study, we investigate the possibility to derive quantitative information on the D/H ratio at Mars from the vertical Lyman-α profiles observed with the “low resolution mode”, and the main limits of the method.</p>


2019 ◽  
Vol 27 (15) ◽  
pp. 20990 ◽  
Author(s):  
Michail Symeonidis ◽  
Radius N. S. Suryadharma ◽  
Rossella Grillo ◽  
Andreas Vetter ◽  
Carsten Rockstuhl ◽  
...  

1989 ◽  
Vol 67 (11) ◽  
pp. 1027-1035 ◽  
Author(s):  
A. R. W. McKellar

The spectrum of CH4 obtained in CH4 plus N2 mixtures at a temperature of 77 K has been recorded with a spectral resolution of 0.14 cm−1 in the region 3800 to 9100 cm−1. The experiments were performed with long paths (66 or 88 m) in a cooled absorption cell using a Fourier-transform spectrometer. Data are presented here at low and medium resolution, and examples of some spectral regions are also shown at high resolution. The complete results are available from the author in an Appendix. Comparisons are made with previous model calculations of CH4 absorption, and with the observed spectrum of Neptune's satellite, Triton. The results should be useful for the interpretation of the spectra of Triton, Titan, and Pluto. They will also be of value for testing model calculations of low-temperature CH4 absorption, which, thus verified, can be used with greater confidence to analyze observations of Jupiter, Saturn Uranus, and Neptune.


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