scholarly journals The structure of the near infra-red bands of methane I-General survey, and a new band at 11,050 a

1936 ◽  
Vol 153 (880) ◽  
pp. 555-567 ◽  
Keyword(s):  
Organic Molecule ◽  
Polyatomic Molecules ◽  
Point Of View ◽  
Resolving Power ◽  
General Survey ◽  
Symmetry Properties ◽  
Infra Red ◽  
Bank Structure ◽  
Theoretical Physicist ◽  
First Time

Methane is the most important of the relatively few polyatomic molecules which may be expected to give rise to spectra suitable for investigation in that portion of the near infra-red which is as yet available to photography. To the chemist it is simplest organic molecule, whilst to Ike theoretical physicist the four directed valencies and their symmetry properties are its most interesting features, From a technical point of view its importance lies in Ike fact that its low moment of inertia gives to the bank structure a coarseness which brings it within reach of the diffraction grating. The amount of information which we possess of the spectrum is already fairly considerable. The first to make a resolution of the fine structure was Cooley, who investigated the bands at 7·7 μ and 3·3 μ and the measurements have since been extended, with the usual type of thermojunction infra-red spectrometer, by Ellis, Moorhead, and Norris and Unger. In the photographic infra-red, measurements at wave-lengths shorter than 1 μ have been made by Dennison and Ingram, and Vedder and Mecke. The present series of papers presents measurements made by the writer in the region λ10,000-12,000 A. They thus overlap into part of the region covered by Norris and Unger and include the bands found by them at λ 11,350, λ 11,620, and λ 11,870. The resolving power of the grating is of course far higher than that employed by them, and muck new detail not shown in their curves is now revealed for the first time. The regularities which they abstract from their measurements prove to be spurious, the result merely of the smoothing out of a many-lined spectrum by the use of too low a resolving power.

scholarly journals The absorption spectra of some polyatomic molecules containing methyl and ethyl radicals

1935 ◽  
Vol 150 (871) ◽  
pp. 603-614 ◽  
Keyword(s):  
Absorption Spectra ◽  
Excited States ◽  
Chemical Change ◽  
Ultra Violet ◽  
Polyatomic Molecules ◽  
Point Of View ◽  
Careful Examination ◽  
Discrete Band ◽  
Infra Red ◽  
Ethyl Radicals

Although measurements on the ultra-violet absorption spectra of polyatomic molecules have rapidly multiplied in recent years, probably in no case has the structure of the entire spectrum been satisfactorily and completely interpreted. From the chemical point of view, investi­gations have been mainly directed to the study of “predissociation” processes and their correlation with the primary processes of photo­ chemical change, whilst in addition some knowledge has been gained in regard to the products of photodissociation and energies of linkage. A more careful examination of the matter has now shown that the inferences to be drawn from predissociation phenomena must be made with care, and in many cases additional measurements—for example of fluorescence or of quantum efficiencies—have to be made before the interpretations become unambiguous. From the physical standpoint, only a few band systems have been analysed in detail ( e . g ., ClO 2 , Urey and Johnston*; SO 2 , Watson and Parker,) and even in these the interpretations given may not be accurate. One aspect of the matter which has not yet received much attention, is the nature and type of the vibrations excited in polyatomic molecules. This may prove to be of considerable importance in connection with chemical kinetics. The chief difficulty in the analysis of the spectra of polyatomic mole­cules usually arises from their complexity, whilst the frequent occurrence of purely continuous spectra which may or may not overlap band systems often makes it impossible to derive much knowledge of the molecular excited states. In such cases as the latter, it may be that further in the ultra-violet, i . e ., in the Schumann region, discrete band systems may lead to knowledge of higher electronic states, but this region has so far been little explored. Herzberg and Teller* have recently attempted to con­struct selection rules for electronic and vibrational transitions in poly­atomic molecules, but even when such rules as these are applied and when the infra-red and Raman frequencies are well known, the analysis of most band systems still remains very difficult.

scholarly journals Infra-Red Assisted Synthesis of Prebiotic Glycine

2019 ◽  
Author(s):  
Debora Scuderi ◽  
Ariel F. Perez-Mellor ◽  
Joël Lemaire ◽  
Suvasthika Indrajith ◽  
Jean-Xavier Bardaud ◽  
...  
Keyword(s):  
Organic Molecule ◽  
Photon Density ◽  
Ir Radiation ◽  
Ion Molecule Reactions ◽  
Ir Laser ◽  
Complex Organic Molecule ◽  
Quantum Chemistry Calculations ◽  
Infra Red ◽  
First Time ◽  
Complex Organic

<p>In the present study, we have shown for the first time how glycine can be synthesized under prebiotic-like conditions using an Infra-Red laser to trigger the reaction. In particular, we observed that in the low-density conditions it can be obtained from simple ion-molecule reactions of acetic acid and protonated hydroxylamine. This reaction, studied years ago in more dense conditions [<i>J. Am. Chem. Soc.</i> <b>2007</b>, <i>129</i>, 9910-9917R], was the center of a controversy, since accurate quantum chemistry calculations have shown that it is not barrierless [<i>Astrophys. J.</i> <b>2012</b>, <i>748</i>, 99] such that a source of energy is needed. In space, and more in general in prebiotic conditions (interstellar medium, comets, asteroids) temperature is very low but the photon density can be important. Here we propose a way of synthesizing such complex organic molecule in a very low-pressure environment (about 10<sup>-3</sup> mbar). This way of forming complex organic molecule is of relevance also beyond the prebiotic interest of finding a scenario which was at the origin of the synthesis of such molecules. In fact our work proposes a new way of assisting reactions using IR radiation. Only few cases were found in which IR can trigger complex reactions (i.e. not simple dissociations) while there is a clear interest of using such low-energy radiation. This study will be at the basis of new researches devoted to find other reactions which can be assisted by IR laser.</p>

scholarly journals Infra-Red Assisted Synthesis of Prebiotic Glycine

2019 ◽  
Author(s):  
Debora Scuderi ◽  
Ariel F. Perez-Mellor ◽  
Joël Lemaire ◽  
Suvasthika Indrajith ◽  
Jean-Xavier Bardaud ◽  
...  
Keyword(s):  
Organic Molecule ◽  
Photon Density ◽  
Ir Radiation ◽  
Ion Molecule Reactions ◽  
Ir Laser ◽  
Complex Organic Molecule ◽  
Quantum Chemistry Calculations ◽  
Infra Red ◽  
First Time ◽  
Complex Organic

<p>In the present study, we have shown for the first time how glycine can be synthesized under prebiotic-like conditions using an Infra-Red laser to trigger the reaction. In particular, we observed that in the low-density conditions it can be obtained from simple ion-molecule reactions of acetic acid and protonated hydroxylamine. This reaction, studied years ago in more dense conditions [<i>J. Am. Chem. Soc.</i> <b>2007</b>, <i>129</i>, 9910-9917R], was the center of a controversy, since accurate quantum chemistry calculations have shown that it is not barrierless [<i>Astrophys. J.</i> <b>2012</b>, <i>748</i>, 99] such that a source of energy is needed. In space, and more in general in prebiotic conditions (interstellar medium, comets, asteroids) temperature is very low but the photon density can be important. Here we propose a way of synthesizing such complex organic molecule in a very low-pressure environment (about 10<sup>-3</sup> mbar). This way of forming complex organic molecule is of relevance also beyond the prebiotic interest of finding a scenario which was at the origin of the synthesis of such molecules. In fact our work proposes a new way of assisting reactions using IR radiation. Only few cases were found in which IR can trigger complex reactions (i.e. not simple dissociations) while there is a clear interest of using such low-energy radiation. This study will be at the basis of new researches devoted to find other reactions which can be assisted by IR laser.</p>

Thanato-Laboratorien. Theorien von Tod und Sterben und Elias Canettis Buch gegen den Tod

2020 ◽  
Vol 4 (1) ◽  
pp. 67-86
Author(s):  
Elisabeth Heyne
Keyword(s):  
Human Life ◽  
Death And Dying ◽  
Point Of View ◽  
Visual Images ◽  
Elias Canetti ◽  
History Of ◽  
Series Of Experiments ◽  
First Time ◽  
Textual Form ◽  
Or History

AbstractAlthough visual culture of the 21th century increasingly focuses on representation of death and dying, contemporary discourses still lack a language of death adequate to the event shown by pictures and visual images from an outside point of view. Following this observation, this article suggests a re-reading of 20th century author Elias Canetti. His lifelong notes have been edited and published posthumously for the first time in 2014. Thanks to this edition Canetti's short texts and aphorisms can be focused as a textual laboratory in which he tries to model a language of death on experimental practices of natural sciences. The miniature series of experiments address the problem of death, not representable in discourses of cultural studies, system theory or history of knowledge, and in doing so, Canetti creates liminal texts at the margins of western concepts of (human) life, science and established textual form.

A Nabatean port on the Red Sea: note on the pottery finds from al-Qusayr (al-Wajh, Saudi Arabia)

2020 ◽  
Author(s):  
Caroline Durand
Keyword(s):  
Saudi Arabia ◽  
19Th Century ◽  
Red Sea ◽  
Point Of View ◽  
The Other ◽  
Trade Routes ◽  
Other Hand ◽  
Roman Egypt ◽  
Pottery Sherds ◽  
First Time

Al-Qusayr is located 40 km south of modern al-Wajh, roughly 7 km from the eastern Red Sea shore. This site is known since the mid-19th century, when the explorer R. Burton described it for the first time, in particular the remains of a monumental building so-called al-Qasr. In March 2016, a new survey of the site was undertaken by the al-‘Ula–al-Wajh Survey Project. This survey focused not only on al-Qasr but also on the surrounding site corresponding to the ancient settlement. A surface collection of pottery sherds revealed a striking combination of Mediterranean and Egyptian imports on one hand, and of Nabataean productions on the other hand. This material is particularly homogeneous on the chronological point of view, suggesting a rather limited occupation period for the site. Attesting contacts between Mediterranean merchants, Roman Egypt and the Nabataean kingdom, these new data allow a complete reassessment of the importance of this locality in the Red Sea trade routes during antiquity.

Ground state molecular parameters of phosphine, PH3, from the simultaneous analysis of the high-resolution infrared, microwave and submillimeterwave spectra

1985 ◽  
Vol 50 (11) ◽  
pp. 2480-2492 ◽  
Author(s):  
Soňa Přádná ◽  
Dušan Papoušek ◽  
Jyrki Kauppinen ◽  
Sergei P. Belov ◽  
Andrei F. Krupnov ◽  
...  
Keyword(s):  
Fourier Transform ◽  
High Resolution ◽  
Ground State ◽  
Unitary Transformation ◽  
Point Of View ◽  
Acoustic Detection ◽  
Molecular Parameters ◽  
Microwave Spectrometer ◽  
Fourier Transform Spectra ◽  
First Time

Fourier transform spectra of the ν2 band of PH3 have been remeasured with 0.0045 cm-1 resolution. Ground state combination differences from these data have been fitted simultaneously with the microwave and submillimeterwave data to determine the ground state spectroscopical parameters of PH3 including the parameters of the Δk = ± 3n interactions. The correlation between the latter parameters has been discussed from the point of view of the existence of two equivalent effective rotational operators which are related by a unitary transformation. The ΔJ = 0, +1, ΔK = 0 (A1 ↔ A2, E ↔ E) rotational transitions in the ν2 and ν4 states have been measured for the first time by using a microwave spectrometer and a radiofrequency spectrometer with acoustic detection.

scholarly journals Line observations of the 30-Dor complex and N159A5 with the MPE imaging NIR spectrometer FAST

1991 ◽  
Vol 148 ◽  
pp. 205-206 ◽  
Author(s):  
A. Krabbe ◽  
J. Storey ◽  
V. Rotaciuc ◽  
S. Drapatz ◽  
R. Genzel
Keyword(s):  
Spatial Resolution ◽  
Molecular Hydrogen ◽  
Near Infrared ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Emission Lines ◽  
Resolving Power ◽  
Max Planck ◽  
First Time ◽  
Infrared Array

Images with subarcsec spatial resolution in the light of near-infrared atomic (Bry) and molecular hydrogen H2 (S(1) v=1-0) emission lines were obtained for some extended, pointlike objects in the Large Magellanic Cloud (LMC) for the first time. We used the Max-Planck-Institut für extraterrestrische Physik (MPE) near-infrared array spectrometer FAST (image scale 0.8”/pix, spectral resolving power 950) at the ESO/MPI 2.2m telescope, La Silla. We present some results on the 30-Dor complex and N159A5.

scholarly journals An exceptionally preserved conulariid from Ordovician erratics of Northern European Lowlands

PalZ ◽  
2021 ◽  
Author(s):  
Consuelo Sendino ◽  
Martin M. Bochmann
Keyword(s):  
Internal Structure ◽  
Late Pleistocene ◽  
Point Of View ◽  
Three Dimensions ◽  
Northern European ◽  
Current Location ◽  
Transport Direction ◽  
First Time ◽  
Erratic Boulder

AbstractA conulariid preserved in three dimensions from Ordovician fluvioglacial erratics of the Northern European Lowlands (North German Plain) is described under open nomenclature. It is assigned to the genus Conularia with similarities to Baltoscandian conulariids. The lithology of the erratic boulder and fauna contained in it provide important information on the origin and transport direction of the sediment preserved in a kame from the Saalian glaciation. This paper deals with the site of origin of the boulder in Baltoscandia analysing the comprised palaeofauna, from a palaeostratigraphic and palaeogeographic point of view, from its deposition in Ordovician times until its arrival at its current location in the Late Pleistocene. It also reveals for the first time the internal structure of the conulariid aperture.

scholarly journals Fractional isospectral and non-isospectral AKNS hierarchies and their analytic methods for N-fractal solutions with Mittag-Leffler functions

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Bo Xu ◽  
Yufeng Zhang ◽  
Sheng Zhang
Keyword(s):  
Spectral Problem ◽  
Fractional Order ◽  
Point Of View ◽  
Adjoint Equations ◽  
Scattering Data ◽  
Bilinear Method ◽  
Soliton Equation ◽  
Scattering Transform ◽  
First Time ◽  
Hirota Bilinear

AbstractAblowitz–Kaup–Newell–Segur (AKNS) linear spectral problem gives birth to many important nonlinear mathematical physics equations including nonlocal ones. This paper derives two fractional order AKNS hierarchies which have not been reported in the literature by equipping the AKNS spectral problem and its adjoint equations with local fractional order partial derivative for the first time. One is the space-time fractional order isospectral AKNS (stfisAKNS) hierarchy, three reductions of which generate the fractional order local and nonlocal nonlinear Schrödinger (flnNLS) and modified Kortweg–de Vries (fmKdV) hierarchies as well as reverse-t NLS (frtNLS) hierarchy, and the other is the time-fractional order non-isospectral AKNS (tfnisAKNS) hierarchy. By transforming the stfisAKNS hierarchy into two fractional bilinear forms and reconstructing the potentials from fractional scattering data corresponding to the tfnisAKNS hierarchy, three pairs of uniform formulas of novel N-fractal solutions with Mittag-Leffler functions are obtained through the Hirota bilinear method (HBM) and the inverse scattering transform (IST). Restricted to the Cantor set, some obtained continuous everywhere but nondifferentiable one- and two-fractal solutions are shown by figures directly. More meaningfully, the problems worth exploring of constructing N-fractal solutions of soliton equation hierarchies by HBM and IST are solved, taking stfisAKNS and tfnisAKNS hierarchies as examples, from the point of view of local fractional order derivatives. Furthermore, this paper shows that HBM and IST can be used to construct some N-fractal solutions of other soliton equation hierarchies.

scholarly journals The SAMI Galaxy Survey: the third and final data release

2021 ◽  
Author(s):  
Scott M Croom ◽  
Matt S Owers ◽  
Nicholas Scott ◽  
Henry Poetrodjojo ◽  
Brent Groves ◽  
...  
Keyword(s):  
Large Scale ◽  
Resolving Power ◽  
Stellar Kinematics ◽  
New Era ◽  
Optical Wavelength ◽  
Astronomical Optics ◽  
Data Release ◽  
Gas Ionization ◽  
Release Data ◽  
First Time

Abstract We have entered a new era where integral-field spectroscopic surveys of galaxies are sufficiently large to adequately sample large-scale structure over a cosmologically significant volume. This was the primary design goal of the SAMI Galaxy Survey. Here, in Data Release 3 (DR3), we release data for the full sample of 3068 unique galaxies observed. This includes the SAMI cluster sample of 888 unique galaxies for the first time. For each galaxy, there are two primary spectral cubes covering the blue (370–570 nm) and red (630–740 nm) optical wavelength ranges at spectral resolving power of R = 1808 and 4304 respectively. For each primary cube, we also provide three spatially binned spectral cubes and a set of standardized aperture spectra. For each galaxy, we include complete 2D maps from parameterized fitting to the emission-line and absorption-line spectral data. These maps provide information on the gas ionization and kinematics, stellar kinematics and populations, and more. All data are available online through Australian Astronomical Optics (AAO) Data Central.

Sign in / Sign up

Export Citation Format

Share Document