ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • SPACE RADIATION  (5)
  • OPTICS  (3)
  • Analytical Chemistry and Spectroscopy  (2)
  • 1
    Electronic Resource
    Electronic Resource
    Mass fragmentation and structure of siphonaxanthin, siphonein and derivatives (1971)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 5 (1971), S. 565-572 
    Details
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: High resolution mass spectrometry has been employed to establish the structural formulae of the unique carotenoid pigment siphonaxanthin, its natural ester, siphonein and several derivatives. Siphonaxanthin exhibits a fragmentation reaction that is unusual among carotenoid pigments, namely, the elimination of carbon dioxide, observed as [M - CO2] and [M - (CO2 + H2O)]. This reaction involves the migration of an oxygen atom. Siphonaxanthol, a partially hydrogenated siphonaxanthin, exhibits a similar reaction involving the elimination of carbon monoxide and formaldehyde. From the fragmentation of derivatives of siphonaxanthin, such as the triacetate, the dimethyl ether and siphonaxanthol, and also from the fragmentation of related pigments, such as loroxanthin and fucoxanthin, the unique structural units responsible for the elimination of the carbon dioxide and carbon monoxide have been identified.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210050508
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Mass spectrometric comparison of ordinary and fully deuterated α- and β-carotene (1972)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 6 (1972), S. 843-851 
    Details
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The individual, deuterated, isomeric α- and β-carotenes were isolated from the green alga, Scenedesmus obliquus, cultivated in D2O containing 99·7 to 99·8 atom percent deuterium. Mass spectroscopy showed that both the α- and β-deuterio-carotene preparations contained principally the fully deuterated pigment molecules (C40D56), small quantities of deuterated molecules with one proton (C40D55H) and yet smaller quantities of deuterated molecules with two protons (C40D54H2). From statistical calculations the deuterio-carotene preparations also contained one to several isotopically-substituted deuterio-carotenes of each mass in the mass range 585 to 599 because of variation of the number of 13C and H atoms per molecule. The mass fragmentation of the deuterated pigments was analogous to that of the respective ordinary α- and β-carotene. It indicated that the protons in the C40D55H and C40D54H2 molecules were distributed approximately randomly in various parts of the structure as in the terminal rings and in the ends and central portions of the polyene chain.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210060804
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    facet.materialart.
    Unknown
    Deep-space optical channel. 1: Noise mechanisms (1981)
    In:  Other Sources
    Details
    Publication Date: 2011-08-18
    Description: The noise due to various sources in the deep space optical channel with a space based receiver is analyzed. It is found that the worst case conditions occur during the encounter phase with planets.
    Keywords: OPTICS
    Type: The Telecommun. and Data Acquisition Progr. Rept. 42-64; p 180-186
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 4
    facet.materialart.
    Unknown
    Waveguide PIN junction electrooptic phase modulators Theoretical analysis and design criteria (1985)
    In:  Other Sources
    Details
    Publication Date: 2011-08-19
    Description: Basic design equations for waveguide PIN heterojunction electrooptic phase modulators utilizing the linear electrooptic effect are derived, and criteria for optimum operation (in terms of obtainable phase shifts) are discussed. Although the numerical examples pertain to devices fabricated of the AlGaAs system on (100) substrates, the same method can be directly applied to modulators fabricated of other materials.
    Keywords: OPTICS
    Type: Applied Optics (ISSN 0003-6935); 24; 1996-200
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 5
    facet.materialart.
    Unknown
    Two populations and models of gamma ray bursts (1993)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Gamma-ray burst statistics are best explained by a source population at cosmological distances, while spectroscopy and intensity histories of some individual bursts imply an origin on Galactic neutron stars. To resolve this inconsistency I suggest the presence of two populations, one at cosmological distances and the other Galactic. I build on ideas of Shemi and Piran (1990) and of Rees and Mesozaros (1992) involving the interaction of fireball debris with surrounding clouds to explain the observed intensity histories in bursts at cosmological distances. The distances to the Galactic population are undetermined because they are too few to affect the statistics of intensity and direction; I explain them as resulting from magnetic reconnection in neutron star magnetospheres. An appendix describes the late evolution of the debris as a relativistic blast wave.
    Keywords: SPACE RADIATION
    Type: NASA-CR-194762 , NAS 1.26:194762
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 6
    facet.materialart.
    Unknown
    Relativistic shock spectra: A prediction (1994)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: I argue that particles heated by relativistic shocks should assume an equilibrium energy distribution. This leads to a synchrotron spectrum F(sub nu) varies as nu(sup 1/3) up to approximately the critical frequency nu(sub 0) of an electron with the mean electron energy. Application to gamma ray bursts (GRB's) implies that a burst with 10(exp -5) erg/(sq cm s) of soft gamma-rays and h(nu(sub 0)) = 300 KeV should be about 18th magnitude in visible light and a few micro-Jy at 1 GHz (less if self-absorbed).
    Keywords: SPACE RADIATION
    Type: NASA-CR-194764 , NAS 1.26:194764
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 7
    facet.materialart.
    Unknown
    Radio and optical emission: Spectral shapes and breaks in GRB (1994)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Relativistic blast wave models of Gamma Ray Bursts (GRB) predict the spectrum of the emitted synchrotron radiation. The electrons in the shocked region are heated to a Wien distribution whose 'temperature' is 1/3 of the mean electron energy. This energy determines a characteristic (break) frequency of synchrotron radiation. At much lower frequencies, a spectrum F(sub nu) varies as nu(sup 1/3) is predicted independently of the details of the emitting region. This is consistent with the observed soft x ray emission of GRB. It implies low visible and radio intensities, unless there are collective emission processes.
    Keywords: SPACE RADIATION
    Type: NASA-CR-194763 , NAS 1.26:194763
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 8
    facet.materialart.
    Unknown
    The deep space optical channel. 2: Wave propagation effects (1981)
    In:  CASI
    Details
    Publication Date: 2019-06-28
    Description: Propagation effects of optical waves in the deep space optical channel with a spacebased receiver are analyzed. It is found that these effects are negligible for all practical interplanetary systems designs.
    Keywords: OPTICS
    Type: The Telecommun. and Data Acquisition Rept.; p 53-58
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 9
    facet.materialart.
    Unknown
    Low-frequency spectra of gamma-ray bursts (1994)
    In:  Other Sources
    Details
    Publication Date: 2019-08-28
    Description: Particles with energies below the mean energy E(sub 0) in relativistic shocked plasmas should assume an equilibrium energy distribution. This leads to a synchrotron spectrum F(sub nu) proportional to nu(exp 1/3) up to approximately the critical frequency nu(sub 0) of an electron with the energy E(sub 0). Application to gamma-ray bursts (GRBs) implies that a burst with 10(exp -5) ergs/sq cm/s of soft gamma rays and h nu(sub 0) = 300 keV should simultaneously be about 18th magnitude in visible light and a few micro-J at 1 GHz (less if self-absorbed); the low-freqency intensities peak later at higher values.
    Keywords: SPACE RADIATION
    Type: Astrophysical Journal, Part 2 - Letters (ISSN 0004-637X); 432; 2; p. L107-L109
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 10
    facet.materialart.
    Unknown
    Radiation transfer in gamma-ray bursts (1992)
    In:  Other Sources
    Details
    Publication Date: 2019-08-28
    Description: We have calculated gamma-ray radiative transport in regions of high-energy density, such as gamma-ray burst source regions, using a discrete ordinate, discrete energy group method. The calculations include two-photon pair production and annihilation, as well as three-photon annihilation. The radiation fields itself acts as an absorbing medium, and the optical depth depends on its intensity, so the problem is intrinsically nonlinear. Spherical divergence produces effective collimation of the flux. At high optical depth the high energy (E is greater than 1 MeV) portion of the emergent spectrum assumes a nearly universal form. An approximate limit is derived for the high-energy flux from a gamma-ray burst source region of given size, and the implications of this limit for the distance to the 1979 March 5 event are briefly discussed. We discuss more generally the problem of very luminous bursts, and implications of Galactic halo distances for flare models.
    Keywords: SPACE RADIATION
    Type: Astrophysical Journal, Part 1 (ISSN 0004-637X); 399; 1; p. 100-107.
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...