Abstracts - faqs.org

Abstracts

Zoology and wildlife conservation

Search abstracts:
Abstracts » Zoology and wildlife conservation

Infrared emission spectra of candidate interstellar aromatic molecules

Article Abstract:

Neutral polycyclic aromatic hydrocarbons (PAH) of small size may contribute to less than 10% of the emissions in the unidentified infrared bands (UIR) of intersellar sources. In the laboratory, ultraviolet-laser-induced desorption was used to incorporate excited gas phase PAHs in a low-infrared-background cryogenic vacuum chamber. Bands with substantial differences appearing in typical spectral regions combine to generate an apparent continuum in the UIR spectra between 5.5 and 9.5 micrometers. The 3.3 micrometer bands present in the spectra exhibit considerable invariance in frequency among the various PAHs.

Author: Saykally, R.J., Cook, D.J., Schlemmer, S., Balucani, N., Wagner, D.R., Steiner, B.
Publisher: Macmillan Publishing Ltd.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1996
Measurement, Spectra, Aromatic compounds, Infrared spectra

User Contributions:

Comment about this article or add new information about this topic:

CAPTCHA


Characterization of a cage form of the water hexamer

Article Abstract:

Terahertz laser vibration-rotation tunnelling spectra reveals that the stable form of (H2O)6 has a cage-like structure supported by eight hydrogen bonds. The high intermolecular zero-point energies of the hydrogen bonds are important for the low energy structure. Calculations based on the diffusion quantum Monte Carlo technique indicate that the O-O bond has an average distance of 2.85 Angstroms for the cage hexamer and 2.76 Angstroms for the cyclic isomer. The values compare well with that of liquid water at 298 degrees Kelvin and ice at 223 degrees Kelvin respectively.

Author: Liu, K., Saykally, R.J., Brown, M.G., Carter, C., Gregory, J.K., Clary, D.C.
Publisher: Macmillan Publishing Ltd.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1996
Methods, Water, Hydrogen bonding, Hydrogen bonds, Chemical bonds, Tunneling spectroscopy

User Contributions:

Comment about this article or add new information about this topic:

CAPTCHA


An enhanced cosmic-ray flux towards Persei inferred from a laboratory study of the H3+--e- recombination rate

Article Abstract:

Study of diffuse interstellar clouds in which the molecular ion H3+ is plentiful has resulted in the discovery that the ionization rate within the clouds is 40 times faster than previously known. If this ionization rate is found to be standard in diffuse clouds, it will allow one of the basic conflicts in interstellar chemistry to be resolved.

Author: Thomas, R., Saykally, R.J., McCall, B.J., Huneycutt, A.J., Geballe, T.R., Djuric, N., Dunn, G.H., Semaniak, J., Novotny, O, Al-Khalili, A., Ehlerding, A., Hellberg, F., Kalhori, S., Neau, A., Osterdahl, F., Larsson, M.
Publisher: Macmillan Publishing Ltd.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 2003
Science & research, Ionization, Cosmic dust

User Contributions:

Comment about this article or add new information about this topic:

CAPTCHA


Subjects list: Research, Analysis
Similar abstracts:
  • Abstracts: The Geminga supernova as a possible cause of the local interstellar bubble. Detection of high-velocity 26Al towards the Galactic Centre
  • Abstracts: Photodesorption from low-temperature water ice in interstellar and circumsolar grains. Rough stuff at Saturn
  • Abstracts: Is pattern vision in insects mediated by 'cortical' processing? Feature-detecting neurons in dragonflies
  • Abstracts: Injection of adult neurospheres induces recovery in a chronic model of multiple sclerosis. Crick's immodest ambitions
  • Abstracts: Habitat selection and breeding status of Swainson's warblers in southern Missouri. Demographic factors contributing to high raccoon densities in urban landscapes
This website is not affiliated with document authors or copyright owners. This page is provided for informational purposes only. Unintentional errors are possible.
Some parts © 2025 Advameg, Inc.