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  • 1975-1979  (7)
  • 1970-1974
  • 1945-1949
  • 1977  (4)
  • 1975  (3)
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Years
  • 1975-1979  (7)
  • 1970-1974
  • 1945-1949
Year
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Solar physics 43 (1975), S. 337-350 
    ISSN: 1573-093X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The spectral composition and spatial distribution of equatorial coronal emission near 304 Å is examined. Spectral scans indicate that the predominant line is from Si xi. Comparisons of observations with calculations of intensity changes with altitude indicate that collisional excitation is important near the Sun but that photoexcitation becomes dominant beyond about 1.3 R ⊙ from the solar center. Observed and calculated intensities are in approximate agreement for abundances and electron densities that are within the range of observed values.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Solar physics 53 (1977), S. 435-444 
    ISSN: 1573-093X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Data obtained by the OSO-7 spectroheliograph on strong XUV lines of five, different Fe ions from the outer equatorial corona are presented. Interpretation of the data with a spherically symmetric model atmosphere gives average ion abundances for lines of sight at 0.3R ⊙ from the limb. Fe xvi is usually more abundant than Fe xv, xiv, xii and ix, but there are times when Fe xii is more abundant than the other ions. The deviation of measured relative abundances of Fe xii, xiv, and xvi from predictions of ionization equilibrium at one temperature seems to indicate that there are appreciable temperature variations along lines of sight. Element abundances are very uncertain since they appear to depend so heavily on likely but unknown density irregularities along lines of sight.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Solar physics 42 (1975), S. 487-496 
    ISSN: 1573-093X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The abundance of Fe relative to H is obtained by using resonantly scattered intensities of λ 284 of Fe XV that were measured with OSO-7 and resonantly scattered intensities of Lα of H I that were obtained by Gabriel (1971). Because of possible differences in electron densities along lines of sight for these non-simultaneous measurements and in relative calibrations, results are rather uncertain but still indicate that the average Fe abundance relative to H in the corona appears to be at least as large as a recent photospheric abundance. Some limitations in using this method for obtaining abundances are examined for future experiments with simultaneous measurements and well calibrated detectors.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1573-8868
    Keywords: data processing ; discriminant analysis ; graphics ; mapping ; sampling ; simulation ; geochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Mathematics
    Notes: Abstract The exploration geochemist faces a serious problem in reconciling theoretical statistics with the empirical distribution of elements in materials in the earth's crust. The results of computer-simulation experiments being conducted by the Exploration Geochemistry Group at the University of New Brunswick illustrate some of the problems of the relation between frequency distributions and spatial distributions of elements and raise some interesting questions about sampling patterns and physical size of samples. Most importantly, the simulation experiments and empirical examples support the contention that attempts to make an assumption of normality more efficient by performing log transformations on positively skewed data may defeat the purpose of statistical analysis for exploration work. New developments in computer-data presentation and interpretation, including population sorting and classification, illustrate the increasing use of the computer in exploration geochemistry.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Mathematical geology 9 (1977), S. 191-198 
    ISSN: 1573-8868
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Mathematics
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Journal of materials science 12 (1977), S. 1125-1133 
    ISSN: 1573-4803
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The design of high performance SAW resonators and reflection pulse compression filters using grooves as the reflective arrays requires that the profiles of the grooves be rectangular and reproducible. The use of neutralized ion-beam technology has largely been adopted for etching these grooves in quartz and lithium niobate because of the precision and control which can be exercised in its use. The experimental work presented here asserts the major contribution that redeposition makes in the evolution of ion-beam etched topography of amorphous, polycrystalline and crystalline materials in a way which is directly useful to the determination of groove profiles. Data are also presented on the relationship between the incidence angle of the ion beam and the etch rate of some important SAW materials indicating the connection between this function and the etching characteristics of the materials.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Journal of materials science 12 (1977), S. 1125-1133 
    ISSN: 1573-4803
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The design of high performance SAW resonators and reflection pulse compression filters using grooves as the reflective arrays requires that the profiles of the grooves be rectangular and reproducible. The use of neutralized ion-beam technology has largely been adopted for etching these grooves in quartz and lithium niobate because of the precision and control which can be exercised in its use. The experimental work presented here asserts the major contribution that redeposition makes in the evolution of ion-beam etched topography of amorphous, polycrystalline and crystalline materials in a way which is directly useful to the determination of groove profiles. Data are also presented on the relationship between the incidence angle of the ion beam and the etch rate of some important SAW materials indicating the connection between this function and the etching characteristics of the materials.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
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