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  • 1
    Electronic Resource
    Electronic Resource
    Choline acetyltransferase inhibitors. Configurational and electronic features of styrylpyridine analogs (1969)
    s.l. : American Chemical Society
    Journal of medicinal chemistry 12 (1969), S. 134-138 
    Details
    ISSN: 1520-4804
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/jm00301a034
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  • 2
    Electronic Resource
    Electronic Resource
    Choline acetyltransferase inhibitors. Dimensional and substituent effects among styrylpyridine analogs (1970)
    s.l. : American Chemical Society
    Journal of medicinal chemistry 13 (1970), S. 221-224 
    Details
    ISSN: 1520-4804
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/jm00296a013
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  • 3
    Electronic Resource
    Electronic Resource
    Resonance Raman and infrared spectra of [CH"3C"5H"4NiPh"2PC"3H"6PPh"2].B"1"1H"1"4
    Amsterdam : Elsevier
    Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy Section 48 (1992), S. 1035-1039 
    Details
    ISSN: 0584-8539
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/0584-8539(92)80184-X
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  • 4
    Electronic Resource
    Electronic Resource
    Reference models of sunspot chromospheres (1986)
    Springer
    Astrophysics and space science 118 (1986), S. 173-175 
    Details
    ISSN: 1572-946X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Recent observational and theoretical studies of the structure of umbral chromosphres have led us to propose new models of the region. We combine space and ground based determinations of the densitytemperature structure of the transition region with existing Caii H, K, and IR triplet spectral data to establish relatively high density, ‘gradient’ models of the sunspot chromosphere. Avrett in 1981 presented theSunspot Sunspot Model which can be characterized as a physically extended, low density, plateau model. However, in a similar study, the authors (Beebeet al., 1982) pointed out that the relatively high transition region pressures derived from space observations indeed are required to reproduce high resolution Caii spectral features. Studies of the umbral chromosphere as a resonant cavity for slow-mode magneto-acoustic waves producing umbral oscillations (Zhugzhdaet al., 1984) also lead to atmospheres of relatively small physical thickness, thus higher densities.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00651124
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  • 5
    Electronic Resource
    Electronic Resource
    The chromosphere above a sunspot umbra (1982)
    Springer
    Solar physics 79 (1982), S. 31-39 
    Details
    ISSN: 1573-093X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Spectra of several strong lines of sunspots have been obtained with the Echelle spectrograph at the Vacuum Tower Telescope, Sacramento Peak Observatory. With a variety of model atmospheres, Ca ii H, K, and λ18498 line profiles were calculated using a non-LTE line formation procedure. In the present study we examined only a specific part of the sunspot umbra which is thought to be coolest over the spot. An optimum model representing such a region is presented and its physical properties are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00146971
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  • 6
    Electronic Resource
    Electronic Resource
    POWER SPECTRA OF SOLAR NETWORK AND NON-NETWORK FIELDS (1997)
    Springer
    Solar physics 171 (1997), S. 269-282 
    Details
    ISSN: 1573-093X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract We report new properties of solar magnetic fields in a quiet region as found from their magnetic power spectra. The power spectra of network and intranetwork fields (non-network fields) are separately calculated from a Big Bear magnetogram obtained with moderately high spatial resolution of 1.5 arc sec and a high sensitivity reaching 2 Mx cm-2. The effect of seeing on the power spectrum has been corrected using Fried's (1966) Modulation Transfer Function with the seeing parameter determined in our previous analysis of the magnetogram. As a result, it is found that the two-dimensional power spectra of network and non-network fields appear in a form: Γ( $$k_0 $$ ≲ $$k $$ ≲ $$k $$ 1) ∼ $$k $$ -1 and Γ( $$k $$ ≳ $$k $$ 1) ∼ $$k $$ -3.5. Here $$k $$ 0 ≈ 0.47 Mm-1 for network fields and $$k $$ 0 ≈ 0.69 Mm-1 for non-network fields, the latter of which corresponds to the size of mesogranulation; $$k $$ 1 ≈ 3.0 Mm-1 for both, which is about the size of a large granule. The network field spectrum below $$k $$ 0 appears nearly flat, whereas that of non-network fields instead decreases towards lower wave numbers as Γ( $$k $$ ) ∼ $$k $$ 1.3. The turnover behavior of magnetic field spectra around $$k $$ 1 coincides with that found for the velocity power spectrum, which may justify the kinetic approach taken in previous theoretical studies of the solar magnetic power spectra.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1004904406126
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  • 7
    Electronic Resource
    Electronic Resource
    Photoelectric line profiles in umbral spectra (1972)
    Springer
    Solar physics 23 (1972), S. 58-77 
    Details
    ISSN: 1573-093X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Umbral line profiles of Hα, Na D2 and Hei 10830 have been observed photoelectrically with a pressure scanning spectrometer, URSIES (Ultravariable Resolution Single Interferometer Echelle Scanner). Intermittent pulse counting techniques are applied with integration times as short as 0.8 s which permits selection of moments of good seeing and guiding even in poor climates. The Hα line profile shows in a medium-sized spot (A u = 100 × 10–6 SH) a pronounced weakening in the wings but a persistence of the line core in agreement with the results of Fricke and Elsässer (1965). The profile of the Hei 10830 line shows an unexpected strengthening over the umbra of the two spots which have been observed. The strengthening of the line in the umbral spectrum of a third spot has been confirmed by Dr. Mallia at the Oxford Solar Station (Gornergrat, Switzerland). Na D2 line profile together with continuum observations at λ4260, λ5890, and λ6530 have been accounted for with an empirical (T, τ) relation by one of us (Yun, 1971). The wavelength dependence and the absolute values from 4000 Å to 14000 Å of the intensity curve generated by this relation shows very good agreement with the intensities observed by Wöhl et al. (1970) in a spot of similar diameter. Precision observations of the continuum at λ5890 indicate umbra-to-disk continuum ratios that are higher (0.104) than the Mercury calibrated value by Mattig (0.086) even when a maximal correction for scattered light is applied. Only Zwaan's (1965) cool umbral model atmosphere approaches Mattig's continuum value, but this model renders the absorption wings in Na D2 much too deep. It is suggested that future definitive observations should be carried out with coronagraphs under coronal skies or in satellites.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00153892
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  • 8
    Electronic Resource
    Electronic Resource
    Intensity ratios of spectral cores Ca ii K to H across a sunspot (1982)
    Springer
    Solar physics 78 (1982), S. 347-349 
    Details
    ISSN: 1573-093X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Ratios of the intensity in the core of the Ca ii K line to the intensity of the H line core across a sunspot (SPO 5007) were determined from measurements of spectra made simultaneously with the Echelle spectrograph at the Vacuum Tower Telescope, Sacramento Peak Observatory. The measured values averaged over the neighboring nonspot region, the penumbra and the umbra are found to be 1.13 ± 0.04, 1.19 ± 0.05, and 1.25 ± 0.03, respectively.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00151613
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  • 9
    Electronic Resource
    Electronic Resource
    Spectral analysis of Hα, Hβ, and Hγ lines of a white-light flare (3B/X6.1) on October 27, 1991 (1996)
    Springer
    Solar physics 163 (1996), S. 361-370 
    Details
    ISSN: 1573-093X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract We have analyzed time series of Hα, Hβ, and Hγ line profiles taken from a 3B/X6.1 flare which occurred on October 27, 1991 in active region NOAA 6891. Each set of the spectra was taken simultaneously for the first 10 min of the flare event with a low and non-uniform time resolution of 10–40 s. A total of 22 sets of Hα, Hβ, and Hγ were scanned by a PDS with absolute intensity calibration to derive the dynamics and energetics of material in the flare region. Our results are as follows: (1) The Balmer line emitting region is accelerated downward to about 50 km s-1 for the first 50 s and then is decelerated to about 10 km s-1 for the next 150 s. (2) The radial velocity peak precedes the Balmer line intensity peak by about 40 s. (3) The total energy radiated from these Balmer lines is estimated to be 4.9 × 1029 erg.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00148007
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  • 10
    Electronic Resource
    Electronic Resource
    THE EFFECT OF SEEING ON SOLAR MAGNETIC FLUX MEASUREMENTS (1997)
    Springer
    Solar physics 171 (1997), S. 35-48 
    Details
    ISSN: 1573-093X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract We investigate the influence of seeing upon measurement of magnetic flux of photospheric fields. For this purpose we quantify seeing variation in one day's observation at Big Bear Solar Observatory in terms of the Fried function, a Modulation Transfer Function for the atmospheric seeing. The temporal variation of seeing quality is compared with that of magnetic flux measured in a quiet region with size 5′ \times 4′ near the solar disk center. A good correlation is found between the seeing change and apparent evolution of magnetic flux values, implying, as a possibility, that magnetic flux measurement might have been modulated by seeing. Based on a simple model of ensembles of Gaussian magnetic elements we argue that even the net flux as well as the total flux can change due to seeing variation if the magnetograph has a finite detection threshold and if the intrinsic fluxes in one and the other polarities are unbalanced.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1004962105138
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