Showing papers on "Fourier transform spectroscopy published in 1983"
TL;DR: New pulse sequences for solvent suppression in Fourier transform NMR are derived and evaluated, and the most satisfactory sequences consist of equally spaced hard pulses with lengths in the ratio of binomial coefficients and phases alternating between 0 and 180°.
805 citations
TL;DR: The data appear to present the first direct spectroscopic evidence of turns in a native protein, as seen in Fourier transform infrared spectra obtained in deuterium oxide solution from 1350 to 1800 cm-1.
485 citations
136 citations
TL;DR: In this article, subtractively normalized interfacial Fourier transform infrared spectroscopy applied to the in situ study of the electrode-electrolyte solution interphase is presented, which is used to obtain difference infrared spectra of electrogenerated intermediates and species adsorbed at the electrode surface.
130 citations
TL;DR: In this article, a Fourier transform ion cyclotron resonance spectrometer (FT ICR) utilizing a superconducting magnet was described, where a narrow-band ultrahigh resolution and a wide-band medium resolution mode can be used.
111 citations
TL;DR: More than 2000 absolute wave numbers of 7 vibrational bands of H216O, H217O, HDO, and H218O were measured with a Fourier interferometer between 1066 and 2296 cm−1 with the greatest uncertainty about 50 × 10−6 cm −1 (1.5 MHz) as discussed by the authors.
Abstract: More than 2000 absolute wave numbers of 7 vibrational bands of H216O, H217O, H218O, and HDO (natural abundance) measured with a Fourier interferometer between 1066 and 2296 cm−1 are provided, with the greatest uncertainty about 50 × 10−6 cm−1 (1.5 MHz). These experimental values extracted from 12 different absorption spectra reveal a much greater consistency and are consequently given in inverse centimeters to the sixth decimal place. The spectral range covered corresponds to a large zone for which experimental accurate data were almost nonexistent. The precise knowledge of these strong atmospheric ν2 bands is of interest for astronomical studies. It will also improve with complementary recent similar work on N2O, the calibration of diode lasers, and Fourier-transform and classical spectrometers and will facilitate the coincidence search with laser radiation. For convenience, the wave numbers of the lines and their absolute uncertainty are given with their rotational and vibrational assignments and their experimental half-widths and intensities.
99 citations
TL;DR: Events occurring during thermally induced fibrillogenesis process can be monitored, in aqueous media and in real time, by Fourier transform infrared spectroscopic techniques.
Abstract: When a solution of collagen molecules, at neutral pH and moderate ionic strength, is warmed from 4 degrees to 30 degrees C, a spontaneous self-assembly process takes place in which native-type collagen fibers are produced. Events occurring during thermally induced fibrillogenesis process can be monitored, in aqueous media and in real time, by Fourier transform infrared spectroscopic techniques. Tentative assignments of observed spectral bands are given.
96 citations
TL;DR: Glycophorin from the human erythrocyte membrane has been isolated in pure form and reconstituted into large unilamellar vesicles comprised of binary mixtures of DPPC and chain perdeuterated 1,2-dimyristoyl-3-sn-phosphatidylcholine (DMPC-d54).
Abstract: Glycophorin from the human erythrocyte membrane has been isolated in pure form and reconstituted into large unilamellar vesicles comprised of binary mixtures of 1,2-dipalmitoyl-3-sn-phosphatidylcholine (DPPC) and chain perdeuterated 1,2-dimyristoyl-3-sn-phosphatidylcholine (DMPC-d54) The effect of temperature and protein on lipid structure and mixing was monitored by using Fourier transform infrared spectroscopy; deuteration of one of the components of the mixture permits observation of the protein interaction with each lipid species The melting curves were analyzed by assuming that each lipid chain can exist in one of two physical states (ie, gel or liquid crystalline), characterized by a temperature-dependent Lorentzian distribution for the line shape of the C-H or C-D stretching vibrations The fraction of each lipid component melted at temperatures within the two-phase region of the phase diagram was calculated and approximate phase diagrams were constructed Addition of protein lowers the liquidus line of the phase diagram while leaving the solidus line essentially unchanged No lipid phase separation is observed The effect of protein is more pronounced on the DPPC component than on the DMPC-d54 The former is significantly more disordered and/or fluidized at all lipid mole fractions in the ternary system than in the binary phospholipid mixture
81 citations
TL;DR: In this paper, the new technique of IR photothermal beam deflection Fourier transform spectroscopy (IR-PDS) is outlined and the applications of IR PDS to carbon materials is described.
68 citations
TL;DR: In this paper, the use of a high-resolution Fourier transform spectrometer was used to analyse the laser-induced fluorescence from a ring dye laser, which allowed the first time of the first use of such a high resolution Fourier Transform Spectrometer.
TL;DR: The maximum entropy method (MEM) is applied to the interferogram data obtained using the technique of Fourier transform spectroscopy for estimating its spectrum with a resolution far exceeding the value set by the spectrometer.
Abstract: The maximum entropy method (MEM) is applied to the interferogram data obtained using the technique of Fourier transform spectroscopy for estimating its spectrum with a resolution far exceeding the value set by the spectrometer. For emission line data, the MEM process is directly used with the interferogram data in place of the regular Fourier transformation process required in Fourier transform spectroscopy. It produces a spectral estimate with an enhanced resolution. For absorption data with a broad background spectrum, the method is applied to a modified interferogram which corresponds to the Fourier transform of the absorptance spectrum. Two results are presented to demonstrate the power of the technique: for the visible emission spectrum of a spectral, calibration lamp and for the infrared chloroform absorption spectrum. Included in the paper is a discussion of the problems associated with practical use of the MEM.
IBM1
TL;DR: In this paper, a switching circuit was incorporated into the data acquisition electronics of an air-equilibrated IBM IR/98 FTIR Spectrometer such that it is possible to obtain simultaneously both reference and polarization modulated spectrum.
TL;DR: A fast Fourier transform technique is described for simulating the distortion effects of the interferometric spectrum and it is shown that correct information can be retrieved from the distorted spectrum using the nonlinear least-squares method.
Abstract: A fast Fourier transform technique is given for the simulation of those distortion effects in the instrument line shape of the interferometric spectrum that are due to errors in the measured interferogram. The technique is applied to analyses of atmospheric absorption spectra and laboratory spectra. It is shown that the nonlinear least squares method can retrieve the correct information from the distorted spectrum. Analyses of HF absorption spectra obtained in a laboratory and solar CO absorption spectra gathered by a balloon-borne interferometer indicate that the retrieved amount of absorbing gas is less than the correct value in most cases, if the interferogram distortion effects are not included in the analysis.
TL;DR: In this paper, phase error is corrected by multiplying the inverse transform of the measured interferogram by e−iϕ(ω), where ϕ is the phase error in the spectrum.
Abstract: The correction of phase error in Fourier transform spectroscopy is discussed. Phase error is corrected by multiplying the inverse transform of the measured interferogram by e−iϕ(ω), where ϕ(ω) is the phase error in the spectrum. This error is determined from a low-resolution, two-sided interferogram. It is absolutely essential that the truncation-apodization function which multiplies the interferogram have an even part which is symmetric about the x=0 position. If this function is not properly located, large errors in the corrected spectrum can occur.
TL;DR: In this paper, a laser-controlled interferometer was constructed for determining the optical constants of solids by dispersive Fourier transform spectroscopy in the visible and ultraviolet.
TL;DR: In this paper, the authors describe the construction of a Microwave Fourier Transform Spectrometer (MFTS) and demonstrate the achievable linewidth of the system.
TL;DR: In this article, the spectrum of CO2 has been recorded in the 2'μm region using high-resolution Fourier transform spectroscopy, and the effective constants have been determined with good accuracy for the (2001, 0401) and (211l, 0511) triads and the 0112-0000 transition.
Abstract: The spectrum of CO2 has been recorded in the 2 μm region using high resolution Fourier transform spectroscopy. The effective constants have been determined with good accuracy for the (2001, 0401) and (211l, 0511) triads and the 0112–0000 transition. In addition, the vibrational energy of the (3001, 0601)1V level, previously given, has been corrected. The Coriolis resonance, strongly perturbing the (211e1, 051e1)m and (4000, 0800)n levels, has been studied.
TL;DR: In this paper, recent progress toward the application of Fourier transform mass spectrometry to the related problems of mass spectral investigation of polar or high mass nonvolatile molecules is described, and a resolution of 9,000-10,000 is demonstrated for both laser desorption and collision induced dissociation analysis of a number of samples.
TL;DR: In this paper, the versatility of a computer controlled double resonance microwave spectrometer has been exploited in three widely differing ways; for quantitative chemical analysis at the percentage level of specific constituents of a gas mixture; for the spectroscopy of forbidden transitions and wideband spectral searches for allowed transitions in torsional states of acetaldehyde.
TL;DR: In this article, a single human hair was recorded using IR Fourier transform photothermal beam deflection spectroscopy (PBDS) with a single hair, and the results showed that it is possible to examine objects which are very small.
Abstract: We have recently shown that it is possible to carry out nondestructive infrared (IR) spectroscopic studies of solid objects which are very large1–4. It is, however, of equal interest to be able to examine objects which are very small. Consequently, we have recorded spectra of a single human hair, using IR Fourier transform photothermal beam deflection spectroscopy (PBDS)1–8.
TL;DR: In this paper, a new interpolation procedure for interpolation of Fourier transform spectral data, which is based upon interpolation with the "magnitude-Lorentzian" function, is applied to FT-NMR spectroscopy.
TL;DR: In this article, a three and four level double resonance spectroscopy in the microwave region is presented, where a pulsed pump radiation and Fourier transform technique for detection of the signal radiation is used.
Abstract: Abstract We present a new three and four level double resonance spectroscopy in the microwave region. A pulsed pump radiation and Fourier transform technique for detection of the signal radiation is used. This method is complementary to that using continuous microwave pump radiation.
TL;DR: In this paper, a newly developed time resolved Fourier transform infrared spectroscopy was applied to follow microstructural changes in two semicrystalline polymers with time resolution in the order of milliseconds.
Abstract: We have applied a newly developed time resolved Fourier transform infrared spectroscopy to follow microstructural changes in two semicrystalline polymers with time resolution in the order of milliseconds. This is the first demonstration of a spectroscopic technique which is capable of measuring structural changes at the segmental level and relating them to macroscopic changes measured by dynamical mechanical spectroscopy.