3C390．3的弱秒差距尺度喷流及其变化

通过对射电星系３Ｃ３９０．３在历元１９８９．２９及６ｃｍ波长的ＶＬＢＩ观测数据的多软件包成象，辨认出其弱秒差距尺度喷流中几个分离的节，将它们和以前发表及未发表的同一波长的成象结果比较，显示了该源弱秒差距尺度喷流的弯曲和反喷流，并重新证认了喷流中节的视超光速运动。     

Infrared,Raman, and cathodoluminescence studies of impact glasses

Abstract— We studied the infrared reflectance (IR), Raman, and cathodoluminescence (CL) spectroscopic signatures and scanning electron microscope‐cathodoluminescence (SEM‐CL) images of three different types of impact glasses: Aouelloul impact glass, a Muong Nong‐type tektite, and Libyan desert glass. Both backscattered electron (BSE) and CL images of the Muong Nong‐type tektite are featureless; the BSE image of the Libyan desert glass shows only weak brightness contrasts. For the Aouelloul glass, both BSE and CL images show distinct brightness contrast, and the CL images for the Libyan desert glass show spectacular flow textures that are not visible in any other microscopic method. Compositional data show that the SiO₂ composition is relatively higher and the Al₂O₃ content is lower in the CL‐bright areas than in the CL‐dark regions. The different appearance of the three glass types in the CL images indicates different peak temperatures during glass formation: the tektite was subjected to the highest temperature, and the Aouelloul impact glass experienced a relatively low formation temperature, while the Libyan desert glass preserves a flow texture that is only visible in the CL images, indicating a medium temperature. All IR reflectance spectra show a major band at around 1040 to 1110 cm^?1 (antisymmetric stretching of SiO₄ tetrahedra), with minor peaks between 745 and 769 cm^?1 (Si‐O‐Si angle deformation). Broad bands at 491 and 821 cm^?1 in the Raman spectra in all samples are most likely related to diaplectic glass remnants, indicating early shock amorphization followed by thermal amorphization. The combination of these spectroscopic methods allows us to deduce information about the peak formation temperature of the glass, and the CL images, in particular, show glass flow textures that are not preserved in other more conventional petrographic images.     

Curt Teichert - Dokumente zu einer Emigration (Dänemark - Australien - USA)

Curt Teichert (K?nigsberg 1905—Arlington, Virginia 1996) provides in his life story examples of the many hardships and difficulties encountered by emigrants who were fortunate to escape Hitler′s regime. He was a great paleontologist and stratigrapher whose fieldwork on four continents involved nearly every fossil group; his interests were focussed mainly on the Paleozoic and the Triassic. His results and critical remarks on many general topics filled numerous publications. Remarkably, he accomplished all this under partly very unfavorable working conditions. He donated his scientific correspondence from his times in Germany, Denmark and Australia to the Geological Archive in Freiburg. The following article makes use of these documents. Teichert’s professional career started in Germany in the scientifically exciting nineteen-twenties; he worked at the universities in K?nigsberg, Munich and Freiburg/Breisgau. In Freiburg, however, he had serious disagreements with the Director of the Geological Institute there—this in spite of his investigations having produced some excellent results. The times around 1930 were a period of a global economic crisis, and, like many others, he could only survive financially by getting fellowships from different institutions and payments for publications. In 1933, his situation in Germany became even more critical: this was because he had married a “Non-Aryan”. However, he was able to work in Copenhagen from the end of 1933; this was largely a result of his having participated in 1931–1932 in an expedition to Greenland led by the Dane Lauge Koch. Unfortunately, he could not get a permanent position in Copenhagen because the relations between him and the influential Koch became very unpleasant. Noting Hitler′s war preparation, Teichert tried to escape from Europe. He wrote many touching letters to correspondents around the globe, receiving mostly disappointing answers. Finally, in 1937, he succeeded in getting the post of a research paleontologist at the University of Perth, in Western Australia. There he worked very successfully, both in the field and in the laboratory. Additionally, he cooperated with the University in lecturing, and contributed much to its collections. His wife Gertrud assisted him always in his work, with great effectiveness. Yet tenure still eluded him, even after seven years of hard work—tenure was what he wanted, understandably, especially after such a long period of uncertainty. Finally, he succeeded in getting tenure in Eastern Australia , but moved then to the USA in 1954. There his outstanding scientific qualities were fully recognized, both in the Geological Survey and in several universities, also as an editor of several classic publications.     

Nebenmeere im humiden und ariden Klimabereich

Zusammenfassung Nebenmeere im humiden und ariden Klimabereich unterscheiden sich in ihrer Wasserzirkulation. Sie wirkt sich auch auf Organismen und Sedimente aus. Dabei ergeben sich die folgenden beiden Modelle:Schon bei rezenten Fällen kommen Abweichungen vor, etwa durch intensive winterliche Abkühlung, durch die Witterungsverhältnisse an den entscheidenden Verbindungsstraßen zum offenen Ozean, durch klimatische Unterschiede zwischen Einzugsgebiet und Nebenmeer oder in den Lagunen desselben Beckens. Deshalb dürfen diese Modelle nicht schematisch auf fossile Verhältnisse übertragen werden. Die Analyse der einzelnen Faktoren und der Versuch, daraus ein Gesamtbild zu gewinnen, sind wichtiger als das Modell selbst.

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Adjacent seas in humid and arid climates differ in their water circulation patterns. This difference effects both the organisms and the sediment. The following table compares the two ideal models:Even recent examples do, however, show divergences from the ideal model. These discrepancies can develop through severe cooling during winter, anomalous weather condition in the straits leading to the open oceans or through differences in climate between the surrounding land area and the adjacent sea or the lagoons of the same basin. Therefore, one should not attempt to apply this model scheme as a whole to fossil conditions. The analysis of the individual factors, and the attempt to reconstruct a complete picture from them is more important than the model itself.

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Résumé Les mers intérieurs situées sous climat humide se différencient de celles soumises au climat aride par le mode de circulation de leurs eaux. De cette différence découle le parallélisme entre les deux modèles suivants.Des circonstances récentes ont cependant déjà apporté des modifications à cette généralisation schématique: modifications dues, soit à un refroidissement hivernal intensif, soit aux conditions météorologiques des détroits déterminant la communication avec l'océan, soit encore aux différences climatiques existant entre le continent et la mer interieure, ou entre cette dernière et ses lagunes.On ne doit donc pas transposer hâtivement le schéma de ces modèles à celui des paléobassins du même type.L'analyse des différents facteurs, l'essai de déduction d'un schéma d'ensemble sont en fait plus importants que le modèle lui-même.

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Ein Stoss-Kolbenlot für Flachwasser

Zusammenfassung Es wird ein leichtes Gerät beschrieben, das durch das Kolbenlot-Prinzip und die Verwendung von Kunststoff-Folien die Entnahme ungestörter SedimentKerne aus Wassertiefen bis 35 m erlaubt.     

Jahreslagen in Sedimenten der mittleren Adria

Zusammenfassung In einer abgeschnürten Meeresbucht von Mljet herrschen euxinische Verhältnisse, weshalb das Sediment in deren tiefstem Teil feinstgeschichtet ist. An der Hell-Dunkel-Wechsellagerung eines Kerns wird gezeigt, daß die durchschnittlich 0,25 mm mächtigen Doppellagen Jahres schichten sind. Zum Beweis werden sich im Sediment abbildende historische Ereignisse wie auch jahreszeitliche Veränderungen herangezogen. Danach werden im Sommer die hellen, kalzitführenden Schichten, im Herbst-Winter-Frühling die dunklen, organische Substanz, Eisensulfid und Quarz enthaltenden Lagen abgesetzt.     

Nekrolog

Ohne Zusammenfassung