Outflows from Dynamo-Active Protostellar Accretion Discs     

Brigitta von Rekowski  Axel Brandenburg  Wolfgang Dobler  Anvar Shukurov 《Astrophysics and Space Science》2004,292(1-4):493-500

An axisymmetric model of a cool, dynamo-active accretion disc is applied to protostellar discs. Thermally and magnetically driven outflows develop that are not collimated within 0.1 AU. In the presence of a central magnetic field from the protostar, accretion onto the protostar is highly episodic, which is in agreement with earlier work.  相似文献   

The Meteoritical Bulletin*     

Frank Wlotzka 《Meteoritics & planetary science》1990,25(3):237-239

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Erratum: Towards cosmological concordance on galactic scales     

Frank C. van den Bosch  H. J. Mo  Xiaohu Yang 《Monthly notices of the Royal Astronomical Society》2004,348(2):736-736

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A high resolution,multiproxy Late‐glacial record of climate change and intrasystem responses in northwest England     

Richard T. Jones  Jim D. Marshall  Stephen F. Crowley  Alan Bedford  Nigel Richardson  Jan Bloemendal  Frank Oldfield 《第四纪科学杂志》2002,17(4):329-340

A lacustrine carbonate sequence from Hawes Water, Lancashire, UK, has been studied using stable isotopic, lithological, pollen and mineral magnetic analysis. The data reveal four abrupt climatic oscillations in the Late‐glacial Interstadial leading up to the onset of the Loch Lomond Stadial. The data also point to climatic warming relatively early within the stadial, ca. 12 500 GRIP yr, prior to the onset of the Holocene. The oxygen isotope record is taken as a signature of climate forcing against which the response of the lake‐system can be monitored. By adopting this approach it is revealed that the response of the biological system to the rapid climatic oscillations is non‐linear and primarily a function of the antecedent conditions. A significant end‐Devensian isotopic excursion (A) is matched by only minor changes in the cold‐adapted floras and faunas. During the warmer interstadial, the response of the biological ecosystem (events B–D) is clearly influenced by thresholds: major changes in the catchment vegetation associated with relatively minor oscillations in the isotopic signature. The stratigraphical patterns reveal significant lag effects between the onset of climate deterioration and resulting changes in vegetation. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   

Palaeontological and facial features of the Upper Jurassic Hochstegen Marble (Tauern Window, Eastern Alps)     

Wolfgang Kiessling 《地学学报》1992,4(2):184-197

Micropalaeontological, microscopic and mineralogical investigations of the ductily deformed and greenschist-facies metamorphic Hochstegen Marble in the Tauern Window shed new light on its stratigraphy and fades.
New radiolarian and sponge spicule discoveries have been made in cherty limestone marbles. They confirm previous age assignments and permit for the first time a more exact micropalaeontological age determination of early Tithonian for the upper parts of the marble. Forty morphotypes of radiolarians could be distinguished; in one sample a Fisher diversity index of 6 is reached indicating deeper marine conditions. The spicule fauna is also diverse and shows affinity to the S-German Malm. In respect to all the data it can be presumed that carbonate sedimentation of the Hochstegen Marble took place in a deeper marine environment at the southern margin of the European continent (Helvetic realm) during the whole Late Jurassic.  相似文献   

List of forthcoming papers     

Wolfgang Wenzel 《Astrophysics and Space Science》1993,201(1):153-153

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The Meteoritical Bulletin,No. 73*     

Frank Wlotzka 《Meteoritics & planetary science》1992,27(4):477-483

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The angular momentum of gas in protogalaxies – II. The impact of pre-heating     

Frank C. van den Bosch  Tom Abel  Lars Hernquist 《Monthly notices of the Royal Astronomical Society》2003,346(1):177-185

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Our galaxy — A former seyfert?     

Wolfgang Kundt 《Astrophysics and Space Science》1987,129(1):195-201

A re-interpretation is offered for both the galactic center lobe and the high-velocity clouds in the galactic halo: the galactic center lobe is a 2-sided chimney for relativistic pair plasma emerging from the center of the Milky Way (=Sag A^*) and streaming as 2 jets through the halo. The channel walls of the flow serve as cold traps for the galactic fountain whenceHi clouds rain back into the disk.  相似文献   

A field and theoretical analysis of garnet+chlorite+chloritoid+biotite assemblages from the tri-state (MA,CT, NY) area,USA     

Ping Wang  Frank S. Spear 《Contributions to Mineralogy and Petrology》1991,106(2):217-235

The prograde evolution of minerals in metapelites of a Barrovian sequence from the tri-state area (Massachusetts, Connecticut, New York) of the Taconic Range involves assemblages with garnet (Ga), chlorite (Ch), chloritoid (Ct), biotite (Bi) and staurolite (St). Detailed petrologic observations, mineral compositions and chemical zoning in garnet show: (1) garnet high in Mn and Fe but low in Mg is stable with chlorite at grades below those where chloritoid+biotite is found; (2) early formed garnet reacted partially to form Ct+Bi at intermediate grades; (3) at higher grades garnet (with low Mn)+chlorite is again produced, at the expense of chloritoid+biotite, suggesting a reversal in the continuous reaction involving the phases Ga, Ch, Ct and Bi. Thermodynamic modeling of the assemblage Ga+Ch+Ct+Bi±St in the MnKFMASH system reveals: (1) in the MnKFASH system the prograde reaction is Ga+Ch=Ct+Bi whereas in the KFMASH system the prograde reaction is the opposite: Ct+Bi=Ga+Ch; (2) the Ga–Ch–Ct–Bi–St invariant point in the KFMASH system occurs twice, at approximately 6.5 kbar, 545° C and 14.8 kbar, 580° C (although one of them may be metastable in a complex phase system); the appearance of the petrogenetic grid is markedly different from that of Albee, but similar to that of Spear and Cheney; (3) as a consequence, in the KFMASH system, chloritoid+biotite are stable over a wide range of P-T conditions whereas garnet+chlorite assemblages are restricted to a narrow band of P-T conditions; (4) MnO increases the stability field of Ga+Ch relative to both Ct+Bi at low temperatures, and St+Bi at high temperatures; (5) in natural samples the occurrence of Ct+Bi is controlled more by bulk Mg–Fe(-Mn) composition than P-T conditions. Specifically, Ct+Bi is restricted to bulk compositions with Fe/(Mg+Fe+Mn)>0.6. Rocks with Fe/(Mg+Fe+Mn)<0.5 are likely to display only chlorite+biotite at low grade. These observations are consistent with Wang and Spear and Spear and Cheney.  相似文献