100 years of the Czech Geographical Society     

Dušan Trávníček 《GeoJournal》1994,32(3):189-190

Main features of the history and activities of the Czech Geographical Society are described.  相似文献   

Stability range and decomposition of potassic richterite and phlogopite end members at 5–15 GPa     

R. G. Trønnes 《Mineralogy and Petrology》2002,74(2-4):129-148

Summary The phase relations of K-richterite, KNaCaMg₅Si₈O₂₂(OH)₂, and phlogopite, K₃Mg₆ Al₂Si₆O₂₀(OH)₂, have been investigated at pressures of 5–15 GPa and temperatures of 1000–1500 °C. K-richterite is stable to about 1450 °C at 9–10 GPa, where the dp/dT-slope of the decomposition curve changes from positive to negative. At 1000 °C the alkali-rich, low-Al amphibole is stable to more than 14 GPa. Phlogopite has a more limited stability range with a maximum thermal stability limit of 1350 °C at 4–5 GPa and a pressure stability limit of 9–10 GPa at 1000 °C. The high-pressure decomposition reactions for both of the phases produce relatively small amounts of highly alkaline water-dominated fluids, in combination with mineral assemblages that are relatively close to the decomposing hydrous phase in bulk composition. In contrast, the incongruent melting of K-richterite and phlogopite in the 1–3 GPa range involves a larger proportion of hydrous silicate melts. The K-richterite breakdown produces high-Ca pyroxene and orthoenstatite or clinoenstatite at all pressures above 4 GPa. At higher pressures additional phases are: wadeite-structured K₂Si^VISi^IV ₃O₉ at 10 GPa and 1500 °C, wadeite-structured K₂Si^VISi^IV ₃O₉ and phase X at 15 GPa and 1500 °C, and stishovite at 15 GPa and 1100 °C. The solid breakdown phases of phlogopite are dominated by pyrope and forsterite. At 9–10 GPa and 1100–1400 °C phase X is an additional phase, partly accompanied by clinoenstatite close to the decomposition curve. Phase X has variable composition. In the KCMSH-system (K₂CaMg₅Si₈O₂₂(OH)₂) investigated by Inoue et al. (1998) and in the KMASH-system investigated in this report the compositions are approximately K₄Mg₈Si₈O₂₅(OH)₂ and K_3.7Mg_7.4Al_0.6Si_8.0O₂₅(OH)₂, respectively. Observations from natural compositions and from the phlogopite-diopside system indicate that phlogopite-clinopyroxene assemblages are stable along common geothermal gradients (including subduction zones) to 8–9 GPa and are replaced by K-richterite at higher pressures. The stability relations of the pure end member phases of K-richterite and phlogopite are consistent with these observations, suggesting that K-richterite may be stable into the mantle transition zone, at least along colder slab geotherms. The breakdown of moderate proportions of K-richterite in peridotite in the upper part of the transition zone may be accompanied by the formation of the potassic and hydrous phase X. Additional hydrogen released by this breakdown may dissolve in wadsleyite. Therefore, very small amounts of hydrous fluids may be released during such a decomposition. Received April 10, 2000; revised version accepted November 6, 2000  相似文献   

X-Ray Emission From Comet Hale–Bopp     

Lisse  C. M.  Dennerl  K.  Englhauser  J.  Trümper  J.  Marshall  F. E.  Petre  R.  Valinia  A.  Kellett  B. J.  Bingham  R. 《Earth, Moon, and Planets》1997,77(3):283-291

The discovery of X-ray emission from comets has created a number of questions about the physical mechanism producing the radiation. There are now a variety of explanations for the emission, from thermal bremsstrahlung of electrons off neutrals or dust, to charge exchange induced emission from solar wind ions, to scattering of solar X-rays from attogram dust, to reconnection of solar magnetic field lines. In an effort to understand this new phenomenon, we observed but failed to detect in the X-ray the very dusty and active comet C/Hale-Bopp 1995 O1 over a two year period, September 1996 to December 1997, using the ROSAT HRI imaging photometer at 0.1–2.0 keV and the ASCA SIS imaging spectrometer at 0.5–10.0 keV. The results of our Hale-Bopp non-detections, when combined with spectroscopic imaging 0.08–1.0 keV observations of the comet by EUVE and BeppoSAX, show that the emission has the same spectral shape and strong variability seen in other comets. Comparison of the ROSAT photometry of the comet to our ROSAT database of 8 comets strongly suggests that the overall X-ray faintness of the comet was due to an emission mechanism coupled to gas, and not dust, in the comet’s coma. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Robust trend estimation of observed German precipitation     

S. Trömel  C. D. Schönwiese 《Theoretical and Applied Climatology》2008,93(1-2):107-115

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Analysis and interpretation of soft X-ray photographs of coronal active regions taken with Fresnel zone plates     

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   

Buchbesprechungen     

H. Woker  H. E. Vogel  E. Trüeb 《Aquatic Sciences - Research Across Boundaries》1962,24(1):177-180

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Das Phänomen Trias     

Rudolf Trümpy 《International Journal of Earth Sciences》1982,71(3):711-723

Zusammenfassung Kurze Übersicht über paläogeographische, paläotektonische und paläoklimatologische Probleme der Trias, unter Ausklammerung des Germanischen Beckens; allgemeiner Rahmen zu den Referaten der Trias-Tagung 1982 in Würzburg.

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Short review of paleogeographic, paleotectonic and paleoclimatological problems of the Triassic system, outside of the Germanic Basin. General framework to the papers presented at the 1982 symposium on the Triassic.

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Résumé Brève vue d'ensemble des problèmes paléogéographiques, paléotectoniques et paléoclimatiques du Trias, en dehors du bassin germanique. Cadre général des communications présentées lors du symposium sur le Trias de 1982.

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Earth resources,time, and man — A geoscience perspective     

von Engelhardt  W.  Goguel  Jean  Hubbert  M. King  Prentice  J. E.  Price  R. A.  Trümpy  R. 《Environmental Geology》1976,1(4):193-206

The earth with all its inhabitants, including man, has had a long history as a slowly evolving complex system which normally exists in a state of stable dynamic equilibrium. Explosive growth in the human population, in the per capita use of nonrenewable resources, and in the degree of human disruption of established ecosystems — the hallmark of man's recent and rapid emergence as the dominant species on the face of the earth — represents a major departure from this state of equilibrium and an ecological crisis of global dimensions. This growth, and the rapid changes that arise from it, have had such a pervasive influence on the collective experience of man that they have come to be regarded as the normal course of events on a stable earth. This has fostered the notion that growth will always be essential for further improvements in the quality of human life. The emergence of a global technological civilization results from man's ingenuity in devising ways of using an ever increasing proportion of energy available at the earth's surface. Rapid growth began only two hundred years ago when the developing technology of the industrial revolution made possible the large-scale exploitation of the earth's fossil-fuel resources and the creation of positive feedback between growth in technology and growth in fossil-fuel production. Annual growth rates in world production of fossil fuels and ores of representative industrial metals, when compared with the nature and finite magnitude of the earth's resources, lead to the inescapable conclusion that the present episode of exponential growth can only be a transitory epoch of a few centuries duration within the totality of human history. Solar radiation offers the prospect of large supplies of energy with minimal environmental impact. However, constraints on growth due to the finite nature of food and mineral resources and the effects of environmental degradation can only be loosened in this way, not removed. Mankind faces an inevitable transition from a brief interlude of exponential growth to a stable condition characterized by rates of growth so slow as to be regarded essentially as a state of no growth. Failure to respond rationally and promptly to this situation could be disastrous.  相似文献   

Geologie der Iberger Klippen und ihrer Flysch-Unterlage     

Rudolf Trümpy 《Eclogae Geologicae Helvetiae》2006,99(1):79-121

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POLAR 5—an electron accelerator experiment within an aurora. 2. Scattering of an artificially produced electron beam in the atmosphere     

B.N. Maehlum  B. Grandal  T.A. Jacobsen  J. Trøim 《Planetary and Space Science》1980,28(3):279-289

The interaction between an artificially produced narrow beam of electrons and the upper atmosphere has been studied by the POLAR 5 electron accelerator “mother”-“daughter” rocket. It is shown how the beam develops a “halo” of scattered electrons and how the low energy electron population in this “halo” is produced partly during the ionization process (at low altitudes), partly by a “wave-plasma” interaction which accelerates the ionospheric background electrons.  相似文献