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91.
Ohne Zusammenfassung
English Summary: Lake trout and its prey fauna in Swiss mountain lakes)
Die Nahrungsfauna wurde vonGrim⇘s, Nahrungs?kologie und Wachstum der Fische vonNilsson bearbeitet. 相似文献
92.
93.
Guoyin Shen Yingwei Fei Ulf Hålenius Yanbin Wang 《Physics and Chemistry of Minerals》1994,20(7):478-482
Electronic absorption spectra have been measured at room temperature and pressure for polycrystalline samples of (Mg, Fe)SiO3 silicate perovskites synthesized by multi-anvil device. One strong near-infrared band at about 7000 cm-1 and several weak bands in the visible region were found. The near-infrared band at 7000 cm-1 is assigned to a spin-allowed transition of Fe2+ at the 8–12 coordinated site in perovskite. However, definite assignments of the weak bands in the visible region are difficult because of their low intensities and the scattering effect at the gain boundaries. Crystal field calculations for Fe2+ at different sites in perovskite have been carried out based on the crystal structure data. The results agree with the assignment of Fe2+ to the 8–12 coordinated site in perovskite. Crystal field stabilization energy of Fe2+ with coordination number of 8 in perovskite is 3332 cm-1 which is small compared to the octahedral site of magnesiowüstite (4320 cm-1), another important lower-mantle mineral. 相似文献
94.
Mn-activated cathodoluminescence can be used in several fields of carbonate petrography. It may, for instance, be possible to recognize
- cement sequences and their correlation (Tab. 1, Figs. 1, 2, 4; Tab. 2, Fig. 1)
- growth fabrics of skeletons (Tab. 2, Figs. 2, 3, 4; Tab. 3, Figs. 1, 2)
- dolomitisation processes and problems (Tab. 1, Figs. 1, 2; Tab. 4, Fig. 2)
- transformation paths from Mg-calcite to calcite and from aragonite to calcite (Tab. 2, Fig. 1; Tab. 3, Figs. 3, 4; Tab. 4, Fig. 1)
- growth structures in certain types of ooids (Tab. 1, Fig. 4; Tab. 3, Fig. 3; Tab. 4, Fig. 1)
- reworked skeletal particles (Tab. 3, Fig. 4)
- phantom grains and fossil-outlines in a micro- or macrocrystalline groundmass (Tab. 4, Figs. 2, 3)
- healed fissures crossing micro- or macrocrystalline carbonate rocks (Tab. 4, Fig. 4).
95.
The concentration levels of Cd (25 ng l?1), Cu (0.45 μg l?1), Ni (0.48 μg l?1), Fe (0.2–7.0 μg l?1), Pb (40 ng l?1) and Zn (0.80 μg l?1) have been determined in the Danish Sounds and in the Kattegat. Different sampling techniques have been used and analyses have been carried out separately by two different investigators, both using freon-extraction followed by determination by atomic absorption spectrometry (a.a.s.). Except for iron, found mainly in the particulate phase, the metals are found predominantly in a dissolved and labile (extractable) form. The results are compared with trace metal levels found in the two main water masses entering the Kattegat—the North Sea and the Baltic Sea. 相似文献
96.
Ulf Högström Roger Taesler Stig Karlsson Leif Enger Anns Ofi Smedman Högström 《Boundary-Layer Meteorology》1978,15(1):69-80
An extensive urban meteorology project in Uppsala, Sweden, is described. The city itself is considered suitable as a kind of model city, being almost circular, having sharp urban/rural boundaries and being situated in a relatively flat area. The project incorporates numerous measurements. A main station with a 100-m mast is situated at the NE urban/rural border. Its instrumentation consists of a slow-response (profile) system and a turbulence system. The profile instrumentation is described in detail. In addition to the main station, the project comprises: measurements from two 14-m masts, one on the top of a centrally located building, the other mobile; pilot balloon ascents; tethered balloon soundings, car-borne temperature traverses etc. Some preliminary results are presented: analyses of wind profiles from the mast and three-dimensional heat island studies. 相似文献
97.
98.
Zebrafish (Danio rerio) were exposed with 17β‐estradiol (E2) and nonylphenol (NP) in different concentrations. Gene expression analysis was carried out by two different approaches. First, RT‐PCR experiments were performed for the examination of expression levels of the two marker genes vitellogenin and aromatase. This approach showed a significant increase in the expression of the vitellogenin gene in exposed male fish (500 ng/L 17β‐estradiol and 250 μg/L nonylphenol). This egg yolk protein is usually not synthesized in male vertebrates. A slight decrease of expression of the aromatase gene was observed in exposed female zebrafish. Aromatase is known to catalyze the conversion of androgens to estrogens. Second, DNA microarray experiments were carried out, which allow the simultaneous examination of the expression levels of a great number of marker genes. The microarray experiments resulted in an up‐regulation of vitellogenin up to 850‐fold. In addition, several other genes were identified to be up‐regulated by estrogens, for example the high mobility group box protein ssrp1 (78‐fold) or the chaperonin containing t‐complex polypeptide 1, beta subunit cctb (22‐fold). 相似文献
99.
The Glueckstadt Graben, a sedimentary record between the North and Baltic Sea in north Central Europe 总被引:2,自引:1,他引:2
The Glueckstadt Graben is one of the deepest post-Permian structures within the Central European Basin system and is located right at its “heart” at the transition from the North Sea to the Baltic Sea and from the Lower Saxony Basin to the Rynkoebing–Fyn High.The Mesozoic to recent evolution is investigated by use of selected seismic lines, seismic flattening and a 3D structural model. A major tectonic event in the latest Middle–Late Triassic (Keuper) was accompanied by strong salt tectonics within the Glueckstadt Graben. At that time, a rapid subsidence took place within the central part, which provides the “core” of the Glueckstadt Graben. The post-Triassic tectonic evolution of the area does not follow the typical scheme of thermal subsidence. In contrast, it seems that there is a slow progressive activation of salt movements triggered by the initial Triassic event. Starting with the Jurassic, the subsidence centre partitioned into two parts located adjacent to the Triassic “core.” In comparison with other areas of the Central European Basin system, the Glueckstadt Graben was not strongly affected by additional Jurassic and Cretaceous events. During the late Jurassic to Early Cretaceous, the area around the Glueckstadt Graben was affected by relative uplift with regional erosion of the elevated relief. However, subsidence was reactivated and accelerated during the Cenozoic when a strong subsidence centre developed in the North Sea. During Paleogene and Quaternary–Neogene, the two centres of sedimentation moved gradually towards the flanks of the basin.The data indeed point toward a control of post-Permian evolution by gradual withdrawal of salt triggered by the initial exhaustion along the Triassic subsidence centre. In this sense, the Glueckstadt Graben was formed at least partially as “basin scale rim syncline” during post-Permian times. The present day Hamburger, East and Westholstein Troughs are the actual final state of this long-term process which still may continue and may play a role in terms of young processes and, e.g., for coastal protection. 相似文献
100.
Yuriy Maystrenko Ulf Bayer Magdalena Scheck-Wenderoth 《International Journal of Earth Sciences》2005,94(5-6):799-814
The salt tectonics of the Glueckstadt Graben has been investigated in relation to major tectonic events within the basin.
The lithologic features of salt sections from Rotliegend, Zechstein and Keuper show that almost pure salt is prominent in
the Zechstein, dominating diapiric movements that have influenced the regional evolution of the Glueckstadt Graben. Three
main phases of growth of the salt structures have been identified from the analysis of the seismic pattern. The strongest
salt movements occurred at the beginning of the Keuper when the area was affected by extension. This activation of salt tectonics
was followed by a Jurassic extensional event in the Pompeckj Block and Lower Saxony Basin and possibly in the Glueckstadt
Graben. The Paleogene–Neogene tectonic event caused significant growth and amplification of the salt structures mainly at
the margins of the basin. This event was extensional with a possible horizontal component of the tectonic movements. 3D modelling
shows that the distribution of the initial thickness of the Permian salt controls the structural style of the basin, regionally.
Where salt was thick, salt diapirs and walls formed and where salt was relatively thin, simple salt pillows and shallow anticlines
developed. 相似文献