ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

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
  • SOLAR PHYSICS  (55)
  • ASTRONOMY  (50)
  • Computational Chemistry and Molecular Modeling
  • Life and Medical Sciences
  • 1980-1984
  • 1975-1979  (153)
  • 1970-1974
  • 1940-1944  (7)
  • 1977  (153)
  • 1943  (7)
Collection
Publisher
Years
  • 1980-1984
  • 1975-1979  (153)
  • 1970-1974
  • 1940-1944  (7)
Year
  • 1
    Publication Date: 2019-06-27
    Description: Spectral observations of the central region of the Eta Carinae nebula at 4 microns have measured the Brackett-alpha hydrogen recombination-line intensity. The bulk of the line and continuum radiation arises in a small central source which is slightly narrower in the line radiation and is barely resolved by the employed beamwidth of 3.4 arcsec. The continuum radiation is well-fitted by an exponential relation to a distance of 10 arcsec from the central source. The line intensity requires a central source which emits 10 to the 49th power ionizing photons per sec into a region of electron density greater than 1 million per cu cm.
    Keywords: ASTRONOMY
    Type: Astrophysical Journal; vol. 217
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2011-08-17
    Description: To observe the medium energy component of the intense galactic center gamma-ray emission, two balloon flights of a medium energy gamma-ray spark chamber telescope were flown in Brazil in 1975. The results indicate the emission is higher than previously thought and above the predictions of a theoretical model proposed.
    Keywords: ASTRONOMY
    Type: ESA Recent Advan. in Gamma-Ray Astronomy; p 117-124
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 11 (1977), S. 399-413 
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The McIver-Stanton rules concerning the symmetry of transition states have a counterpart in rules concerning the permutation symmetry of single steps in degenerate rearrangements, derivable with the aid of Longuet-Higgins group theory. The generalized rules are illustrated by the widely studied PX5 polytopal rearrangements. The analysis leads to prediction of hitherto unexplored “pseudorotation” pathways for rearrangements in ethyl and homotetrahedryl cations. CNDO computations of system energies, gradients, and curvatures at critical points on the C2H5+ and C5H5+ surfaces indicate that symmetry-breaking in keeping with the permutation-theoretic predictions is a key feature of the low-energy rearrangements of these systems. In particular, computation indicates that the C2v “classical” homotetrahedral cation corresponds to an energy maximum rather than an energy minimum, or a transition state.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Mouse teratocarcinoma cells derived from embryoid bodies of 129SVsl mice were cultured in vitro to permit their differentiation. These cells were then infected with simiam virus 40 (SV40) and 31 cloned cell lines (SVTER) were derived from these cultures. All 31 SVTER cell lines contained the SV40 tumor (T) antigen and grew as permanent lines in culture. Mock-infected embryoid body cultures did not give rise to permanent cell lines. The morphology of each SVTER cell line was distinct and did not change during successive subclonings.The growth properties and tumorigenic potential of all 31 SVTER cell lines were investigated. None of these lines produced tumors in 129SVsl mice. Each cell line was tested for its ability to (1) grow in medium containing 1% serum, (2) plate on a cell monolayer, and (3) form clones in methocel suspension. Only three of the SVTER cell lines were transformed with respect to all three of these criteria. Most of these cell lines were minimal transformation.The SVTER cell lines were tested for creatine phosphokinase (CPK), an enzyme activity characteristic of mouse brain and muscle tissue, and the protease, plasminogen activator (PA) which is found in embryoid bodies and several differentiated cell types. Some of the SVTER cell lines contained high levels of CPK, while others had high levels of PA and a third group of cells contained neither enzyme activity. No SVTER cell line was found with high levels of both these enzyme activities. This result suggests that mutually exclusive sets of genes are expressed in these cells as might be expected from the distinct tissue distribution of the two enzyme activities studied. These SVTER cell lines may be useful in reconstructing developmental pathways of differentiating teratomas in vitro.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Publication Date: 2011-08-17
    Description: Relative abundances of energetic nuclei in the July 4, 1974, solar event are presented. The results show a marked enhancement of abundances that systematically increase with nuclear charge numbers in the range of the observation (Z between 6 and 26) for energies above 15 MeV/nucl. While such enhancements are commonly seen below 10 MeV/nucl, most observations at higher energies are found to be consistent with solar-system abundances. The energy spectrum of oxygen is observed to be significantly steeper than most other solar events studied in this energy region. It is proposed that these observations are characteristic of particle populations at energies of the order of 1 MeV/nucl and that the anomalous features observed may be the result of the high-energy extension of such a population that is commonly masked by other processes or populations that might occur in larger solar events.
    Keywords: SOLAR PHYSICS
    Type: Solar Physics; 55; Dec. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Publication Date: 2011-08-17
    Description: A Michelson interferometer aboard NASA's Kuiper Airborne Observatory has been used to measure the spectrum of Sgr B2 from 40 to 200 kaysers with 5-kayser resolution in a 1.4-arcmin beam. The measured spectrum is smooth and featureless with a broad maximum at about 85 kaysers. The data can be fitted analytically with a model corresponding to thermal emission by a uniform sla of dust filling the beam, with an average temperature of approximately 32 K, an optical depth at 100 microns of about 1.6, and a spectral index of the dust emissivity about 1.5. The absence of features implies either that the source is optically thick or that the emission spectrum of the individual grains is smooth in the passband. The possible physical significance of this model is discussed.
    Keywords: ASTRONOMY
    Type: Astrophysical Journal; vol. 216
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Publication Date: 2011-08-17
    Description: Astrometric data are perturbed by turbulent density fluctuations in the atmosphere over the frequency range from 0.0001 to 10 Hz by amounts that would limit the accuracy of solar-diameter measures significantly. Power spectra of the perturbations are compared with meteorological data to argue that thermal turbulence is dominant above 0.001 Hz and that mechanical turbulence (weather) is important below that frequency. Noise power in astrometry should be comparable under night or day conditions, but site location may be important for the strength of slowly passing waves.
    Keywords: SOLAR PHYSICS
    Type: Astronomy and Astrophysics; 59; 2, Ju; July 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Publication Date: 2011-08-17
    Keywords: ASTRONOMY
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Publication Date: 2011-08-17
    Description: The perturbed motion of a rigid body about its center of mass, is formulated in terms of the six elements: l, the magnitude of the angular momentum vector; h, the total energy; delta and epsilon, two linear functions of the independent variable; and psi(1) and theta (1), two Euler angles that orientate the inertial frame with respect to the unperturbed solution. Solutions from the element formulation and the original Euler equations are numerically compared using shuttle-type data. For applied torques smaller than a given magnitude, the element formulation produced the following results: (1) larger step sizes in the numerical integration of the differential equations, resulting in an overall computational time-saving, and (2) more significant figures of accuracy in the computation of the variables describing the state of the rigid body.
    Keywords: ASTRONOMY
    Type: Celestial Mechanics; 16; Nov. 197
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Publication Date: 2019-06-27
    Description: A significantly improved position for the X-ray source 3U 1921 + 43 has been obtained by ANS and Uhuru. The combined ANS-Uhuru error box is only about 7 by 7 arcmin and is centered on the cD galaxy in the Abell 2319 cluster of galaxies. Radio observations of this cluster indicate that the emission at 610 MHz includes several discrete sources and a weak extended component. This strengthens the general association between extended radio halos and X-ray emission from clusters of galaxies. The radio halo fills the X-ray error box and is consistent with the limits reported for the angular size of the X-ray source
    Keywords: ASTRONOMY
    Type: Astrophysical Journal; vol. 214
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...