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981.
N. Kappelmann J. Barnstedt H. Becker-Ross S. Florek M. Grewing G. Krämer D. Schönberner 《Experimental Astronomy》1997,7(4):361-367
The Spectrum-UV mission, a general purpose ultraviolet observatory equipped with a 170-cm aperture telescope for imaging and spectroscopy in the 912 to 3600 Å range, will be launched in a seven days, high elliptical orbit in the late '90s by a Proton booster. The German contribution to the focal plane instrument complex is described: HIRDES, a High Resolution Double Echelle Spectrograph. 相似文献
982.
Dr. O. Fränzle Prof. 《GeoJournal》1987,15(2):201-208
Digital evalutation of a series of correlative geo-specific maps in different scales and subsequent multivariate data processing in the form of entropy and neighbourhood analyses are the basis of a comparative selection of soil samples for the environmental specimen bank of the Federal Republic of Germany. By means of regionalisation algorithms, partly developed for, or specifically adapted to the present purpose, the optimum location of sampling points was determined and the result corroborated on large-scale maps or by visual inspection, respectively. In addition an index of representativity was defined, grouping soil taxa in terms of acreage and spatial autocorrelation.Once the spatial structure of the soil associations in an area to be sampled is thus determined variogram analysis, in the second step, contributes to definitely select the most appropriate specimens on the basis of a representative sampling grid and with respect to relevant properties, for instance cation or anion exchange capacities and biodegradability potential. 相似文献
983.
984.
On the basis of U-Pb, Rb-Sr and K-Ar isotope analyses of Proterozoic rocks and minerals, a chronology has been established for the tectonic, intrusive and metamorphic evolution of the Svecokarelian orogeny 1750–1950 Ma ago in the Uppsala Region, Eastern Sweden. It is suggested that when synkinematic granitoids intruded the orogenic belt, at a stage of general subsidence and at medium metamorphic conditions (600°C and 3.5–4 kbar), the U-Pb isotope system in zircons closed earlier than the Rb-Sr whole-rock system. The zircon age (1886 Ma) reflects the intrusion and crystallization of the rock melt and the Rb-Sr whole-rock age (1830 Ma) the time when the temperature had decreased below the threshold for 87Sr migration. The Rb-Sr whole rock age (1898 Ma) determined for metaandesites and metadacites reflects a recrystallization related to the intrusion of the granitoids. On the contrary, the more silicic metarhyodacitic volcanic rocks have a Rb-Sr whole rock age (1830 Ma) reflecting the cessation of the synkinematic metamorphism. The difference in the way the Rb-Sr isotope system responds in subsilicic or silicic metavolcanics is probably dependent on the amount of radiogenic 87Sr and on the fixation of 87Sr in Ca-rich minerals. Subsequent, late-kinematic, low amphibolite facies metamorphism has not altered the Rb-Sr ages of the granitoids and the recrystallized metavolcanics. 相似文献
985.
Christian Mätzler 《Solar physics》1973,32(1):241-255
It is shown that the lack of linear polarization in the microwave radiation of solar bursts (reported in a earlier paper) may be explained by spatial dispersion of Faraday rotation. The maximum source diameter s without noticeable destruction of linear polarization is determined by the electron density and the magnetic field strength in the volume, where the linear polarization is generated. In the case where linear polarization is produced by the radiation source, s is smaller than only 20 km. In the other case where linear polarization is produced by mode coupling in a quasi-transverse magnetic field in the corona, the s-values are found to range from 10 to 6000 km, which is still much smaller than the generally adopted sizes of microwave burst sources. The second case has been investigated for several models of magnetic fields. 相似文献
986.
G. Krämer H. J. Einighammer G. Elwert H. Bräuninger H. H. Fink J. Trümper 《Solar physics》1978,57(2):345-367
Soft X-ray photographs of the Sun taken at O vii 21.6 Å and in a spectral band ranging from 13.2 to 22.1 Å have been analysed in order to establish spatially resolved maps of temperature and emission measure for several active regions in the corona. The photographs were taken on 11 March, 1971, and on 2 March, 1972, with Fresnel zone plate cameras which were flown on ESRO and NRL sounding rockets.In Part I of this paper we first deal with those aspects of the instrumentation which are important for setting up a suitable image analysis procedure. We discuss the characteristics of the wavelength dependent image formation by zone plates combined with absorption filters. Results of the calibration of the X-ray film are given. Then we describe a specific iterative data reduction procedure and finally present the resulting maps of temperature and emission measure for a selected active region. In Part II corresponding results for further active regions will be given and discussed. 相似文献
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