Search Results - (Author, Cooperation:G. A. Blake)

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  1. 1
    Staff View
    Publication Date:
    2013-02-01
    Publisher:
    Nature Publishing Group (NPG)
    Print ISSN:
    0028-0836
    Electronic ISSN:
    1476-4687
    Topics:
    Biology
    Chemistry and Pharmacology
    Medicine
    Natural Sciences in General
    Physics
    Published by:
    http://www.nature.com/

    Latest Papers from Table of Contents or Articles in Press
  2. 2
    C. Qi ; K. I. Oberg ; D. J. Wilner ; P. D'Alessio ; E. Bergin ; S. M. Andrews ; G. A. Blake ; M. R. Hogerheijde ; E. F. van Dishoeck
    American Association for the Advancement of Science (AAAS)
    Published 2013
    Staff View
    Publication Date:
    2013-07-23
    Publisher:
    American Association for the Advancement of Science (AAAS)
    Print ISSN:
    0036-8075
    Electronic ISSN:
    1095-9203
    Topics:
    Biology
    Chemistry and Pharmacology
    Computer Science
    Medicine
    Natural Sciences in General
    Physics
    Published by:
    http://www.aaas.org/

    Latest Papers from Table of Contents or Articles in Press
  3. 3
    G. A. Blake ; E. A. Bergin
    Nature Publishing Group (NPG)
    Published 2015
    Staff View
    Publication Date:
    2015-04-10
    Publisher:
    Nature Publishing Group (NPG)
    Print ISSN:
    0028-0836
    Electronic ISSN:
    1476-4687
    Topics:
    Biology
    Chemistry and Pharmacology
    Medicine
    Natural Sciences in General
    Physics
    Published by:
    http://www.nature.com/

    Latest Papers from Table of Contents or Articles in Press
  4. 4
    M. R. Hogerheijde ; E. A. Bergin ; C. Brinch ; L. I. Cleeves ; J. K. Fogel ; G. A. Blake ; C. Dominik ; D. C. Lis ; G. Melnick ; D. Neufeld ; O. Panic ; J. C. Pearson ; L. Kristensen ; U. A. Yildiz ; E. F. van Dishoeck
    American Association for the Advancement of Science (AAAS)
    Published 2011
    Staff View
    Publication Date:
    2011-10-25
    Publisher:
    American Association for the Advancement of Science (AAAS)
    Print ISSN:
    0036-8075
    Electronic ISSN:
    1095-9203
    Topics:
    Biology
    Chemistry and Pharmacology
    Computer Science
    Medicine
    Natural Sciences in General
    Physics
    Keywords:
    Evolution, Planetary ; Extraterrestrial Environment ; *Ice ; *Planets ; *Stars, Celestial ; *Steam
    Published by:
    http://www.aaas.org/

    Latest Papers from Table of Contents or Articles in Press
  5. 5
    Staff View
    Publication Date:
    2011-10-07
    Publisher:
    Nature Publishing Group (NPG)
    Print ISSN:
    0028-0836
    Electronic ISSN:
    1476-4687
    Topics:
    Biology
    Chemistry and Pharmacology
    Medicine
    Natural Sciences in General
    Physics
    Published by:
    http://www.nature.com/

    Latest Papers from Table of Contents or Articles in Press
  6. 6
    Loeser, Jennifer G. ; Schmuttenmaer, C. A. ; Cohen, R. C. ; Elrod, M. J. ; Steyert, D. W. ; Saykally, R. J. ; Bumgarner, R. E. ; Blake, G. A.

    College Park, Md. : American Institute of Physics (AIP)
    Published 1992
    Staff View
    ISSN:
    1089-7690
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Chemistry and Pharmacology
    Notes:
    We have measured and assigned more than 800 new far-infrared absorption lines and 12 new microwave absorption lines of the ammonia dimer. Our data are analyzed in combination with all previously measured far-infrared and microwave spectra for this cluster. The vibration–rotation–tunneling (VRT) states of the ammonia dimer connected by electric-dipole-allowed transitions are separated into three groups that correspond to different combinations of monomer rotational states: A+A states (states formed from the combination of two ammonia monomers in A states), A+E states, and E+E states. We present complete experimentally determined energy-level diagrams for the Ka=0 and Ka=1 levels of each group in the ground vibrational state of this complex. From these, we deduce that the appropriate molecular symmetry group for the ammonia dimer is G144. This, in turn, implies that three kinds of tunneling motions are feasible for the ammonia dimer: interchange of the "donor'' and "acceptor'' roles of the monomers, internal rotation of the monomers about their C3 symmetry axes, and quite unexpectedly, "umbrella'' inversion tunneling.In the Ka=0 A+E and E+E states, the measured umbrella inversion tunneling splittings range from 1.1 to 3.3 GHz. In Ka=1, these inversion splittings between two sets of E+E states are 48 and 9 MHz, while all others are completely quenched. Another surprise, in light of previous analyses of tunneling in the ammonia dimer, is our discovery that the interchange tunneling splittings are large. In the A+A and E+E states, they are 16.1 and 19.3 cm−1, respectively. In the A+E states, the measured 20.5 cm−1 splitting can result from a difference in "donor'' and "acceptor'' internal rotation frequencies that is increased by interchange tunneling. We rule out the possibility that the upper state of the observed far-infrared subbands is the very-low-frequency out-of-plane intermolecular vibration predicted in several theoretical studies [C. E. Dykstra and L. Andrews, J. Chem. Phys. 92, 6043 (1990); M. J. Frisch, J. E. Del Bene, J. S. Binkley, and H. F. Schaefer III, ibid. 84, 2279 (1986)]. In their structure determination, Nelson et al. assumed that monomer umbrella inversion tunneling was completely quenched and that "donor–acceptor'' interchange tunneling was nearly quenched in the ammonia dimer [D. D. Nelson, G. T. Fraser, and W. Klemperer, J. Chem. Phys. 83, 6201 (1985); D. D. Nelson, W. Klemperer, G. T. Fraser, F. J. Lovas, and R. D. Suenram, ibid. 87, 6364 (1987)]. Our experimental results, considered together with the results of six-dimensional calculations of the VRT dynamics presented by van Bladel et al. in the accompanying paper [J. Chem. Phys. 97, 4750 (1992)], make it unlikely that the structure proposed by Nelson et al. for the ammonia dimer is the equilibrium structure.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.463874

    Articles: DFG German National Licenses
  7. 7
    Blake, G. A. ; Laughlin, K. B. ; Cohen, R. C. ; Busarow, K. L. ; Gwo, D.-H. ; Schmuttenmaer, C. A. ; Steyert, D. W. ; Saykally, R. J.

    [S.l.] : American Institute of Physics (AIP)
    Published 1991
    Staff View
    ISSN:
    1089-7623
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Electrical Engineering, Measurement and Control Technology
    Notes:
    A detailed description is presented for a tunable far infrared laser spectrometer based on frequency mixing of an optically pumped molecular gas laser with tunable microwave radiation in a Schottky point contact diode. The system has been operated on over 30 laser lines in the range 10–100 cm−1 and exhibits a maximum absorption sensitivity near one part in 106. Each laser line can be tuned by ±110 GHz with first-order sidebands. Applications of this instrument are detailed in the preceding paper.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.1142410

    Articles: DFG German National Licenses
  8. 8
    Blake, G. A. ; Laughlin, K. B. ; Cohen, R. C. ; Busarow, K. L. ; Gwo, D-H. ; Schmuttenmaer, C. A. ; Steyert, D. W. ; Saykally, R. J.

    [S.l.] : American Institute of Physics (AIP)
    Published 1991
    Staff View
    ISSN:
    1089-7623
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Electrical Engineering, Measurement and Control Technology
    Notes:
    The state of the art in far infrared (FIR) spectroscopy is reviewed. The development of tunable, coherent FIR radiation sources is discussed. Applications of tunable FIR laser spectrometers for measurement of rotational spectra and dipole moments of molecular ions and free radicals, vibration-rotation-tunneling (VRT) spectra of weakly bound complexes, and vibration-rotation spectra of linear carbon clusters are presented. A detailed description of the Berkeley tunable FIR laser spectrometers is presented in the following article.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.1142409

    Articles: DFG German National Licenses
  9. 9
    Staff View
    ISSN:
    1476-4687
    Source:
    Nature Archives 1869 - 2009
    Topics:
    Biology
    Chemistry and Pharmacology
    Medicine
    Natural Sciences in General
    Physics
    Notes:
    [Auszug] Circumstellar accretion disks transfer matter from molecular clouds to young stars and to the sites of planet formation. The disks observed around pre-main-sequence stars have properties consistent with those expected for the pre-solar nebula from which our own Solar System formed ...
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1038/35051033

    Articles: DFG German National Licenses
  10. 10
    Kubicki, J. D. ; Apitz, S. E. ; Blake, G. A.
    Springer
    Published 1995
    Staff View
    ISSN:
    1432-2021
    Source:
    Springer Online Journal Archives 1860-2000
    Topics:
    Chemistry and Pharmacology
    Geosciences
    Physics
    Notes:
    Abstract G2 theory calculations were performed on [H3SiO4]−, H4SiO4, [H3AlO4]2−, [H4AlO4]−, and [H5AlO4]. Molecular structures, atomic charges, and infrared spectra at the HF/6-31G* and MP2/6-31G* levels are compared. The influence of polarization and diffuse functions on the structure of [H3SiO4]− is also examined. Basis set and electron correlation effects on potential energies are assessed by comparing various levels of theory. Proton affinities of these gas-phase molecules and related mineral surface species are predicted based on corrections for cluster-size effects.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1007/BF00209373

    Articles: DFG German National Licenses
  11. 11
    Mundy, L. G. ; McMullin, J. P. ; Blake, G. A.
    Springer
    Published 1995
    Staff View
    ISSN:
    1572-946X
    Keywords:
    Chemistry ; Depletions ; Shocks ; IRAS 05338-0624 ; NGC 1333 IRAS 4
    Source:
    Springer Online Journal Archives 1860-2000
    Topics:
    Physics
    Notes:
    Abstract High resolution interferometer and single-dish observations of young, deeply embedded stellar systems reveal a complex chemistry in the circumstellar environments of low to intermediate mass stars. Depletions of gas-phase molecules, grain mantle evaporation, and shock interactions actively drive chemical processes in different regions around young stars. We present results for two systems, IRAS 05338-0624 and NGC 1333 IRAS 4, to illustrate the behavior found and to examine the physical processes at work.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1007/BF00667826

    Articles: DFG German National Licenses