Editorial     

Carl Sagan 《Icarus》1975,25(3):iii

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Observational Magnetogasdynamics: 21 Years of HI Zeeman Splitting Measurements... and More     

Carl Heiles 《Astrophysics and Space Science》2004,292(1-4):77-88

We review observations of the physical properties of the diffuse ISM HI components, namely the Cold and Warm Neutral Media (CNM and WNM). There is somewhat more WNM than CNM, and at least half of the WNM is not thermally stable. The CNM has typical turbulent Mach number 3. Magnetic fields in the CNM are not as large as expected from the classical flux-freezing argument; neither are magnetic fields always strong enough for the Alfven velocity to equal the turbulent velocity. Nevertheless, they are usually strong enough to put CNM clouds in the magnetically subcritical regime. We identify a probable new source of turbulence for the diffuse ISM. We discuss one very cold cloud that has considerable internal turbulence and, because of its extreme thinness ～0.05 pc, a turbulent crossing time of only ～5 × 10⁴ yr.  相似文献   

Zn and Pb mobility during metamorphism of sedimentary rocks and potential implications for some base metal deposits     

Johannes Hammerli  Carl Spandler  Nicholas H.S. Oliver  Paolo Sossi  Gregory M Dipple 《Mineralium Deposita》2015,50(6):657-664

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Benchmarks for multicomponent reactive transport across a cement/clay interface     

Nicolas C. M. Marty  Olivier Bildstein  Philippe Blanc  Francis Claret  Benoit Cochepin  Eric C. Gaucher  Diederik Jacques  Jean-Eric Lartigue  Sanheng Liu  K. Ulrich Mayer  Johannes C. L. Meeussen  Isabelle Munier  Ingmar Pointeau  Danyang Su  Carl I. Steefel 《Computational Geosciences》2015,19(3):635-653

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R- and J-band photometry of Comets 2P/Encke and 9P/Tempel 1     

Carl W. Hergenrother  Beatrice E.A. Mueller  N.H. Samarasinha 《Icarus》2006,181(1):156-161

Near-simultaneous R- and J-band photometric measurements of the short-period Comets 2P/Encke and the Deep Impact mission target 9P/Tempel 1 were obtained. The resulting R-J colors are +0.82±0.08 mag and +1.46±0.13 mag for Encke and Tempel 1, respectively. Tempel 1's color is redder than the solar R-J color index of +0.76. The Tempel 1 observations directly detected the nucleus while the Encke observations likely suffered from coma contamination.  相似文献   

Cenozoic basin development and its indication of plateau growth in the Xunhua-Guide district     

Liu  ShaoFeng  Zhang  GuoWei  Heller  P. L. 《中国科学:地球科学(英文版)》2007,50(2):277-291

The Xunhua, Guide and Tongren Basins are linked with the Laji Mountain and the northern West Qinling thrust belts in the Xunhua-Guide district. Basin depositional stratigraphy consists of the Oligocene Xining Group, the uppermost Oligocene-Pliocene Guide Group and the Lower Pleistocene. They are divided into three basin phases by unconformities. Basin phase 1 is composed of the Xining Group, and Basin phase 2 of the Zharang, Xiadongshan, Herjia and Ganjia Conglomerate Formations in the Guide Group, and Basin phase 3 of the Gonghe Formation and the Lower Pleistocene. Three basin phases all develop lacustrine deposits at their lower parts, and alluvial-braided channel plain depositional systems at upper parts, which constitute a coarsening-upward and progradational sequence. Basin deposition, paleocurrent and provenance analyses represent that large lacustrine basin across the Laji Mountain was developed and sourced from the West Qinling thrust belt during the stage of the Xining Group (Basin phase 1), and point-dispersed alluvial fan-braided channel plain deposition systems were developed beside the thrust and uplifted Laji Mountain and sourced from it, as thrusting migrated northwards during the stage of the Guide Group (Basin phase 2). Evolution of basin-mountain system in the study area significantly indicates the growth process of the distal Tibetan Plateau. The result shows that the Tibetan Plateau expanded to the northern West-Qinling at Oligocene (29–21.4 Ma) by means of northward folded-and-thrust thickening and uplifting and frontal foreland basin filling, and across the study area to North Qilian and Liupan Mountain at the Miocene-Pliocene (20.8–2.6 Ma) by means of two-sided basement-involved-thrust thickening and uplifting and broken foreland basin filling, and the distant end of Tibetan Plateau behaved as regional erosion and intermontane basin aggradational filling during the Pliocene and early Pleistocene (2.6–1.7 Ma).

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Lower Jurassic magnetostratigraphy at the Breggia Gorge (Ticino, Switzerland) and Alpe Turati (Como, Italy)     

F. Horner  F. Heller 《Geophysical Journal International》1983,73(3):705-718

Summary. The Breggia gorge (Ticino, Switzerland) provides a continuous outcrop of Mesozoic limestones covering the time between the Lower Jurassic and Upper Cretaceous. The Jurassic section from the Lower Pliens-bachian to Aalenian is well dated by ammonites. The limestones of these stages are a good quality recorder of the polarity of the geomagnetic field during this time interval. More than 500 cores have been drilled along a 120 m thick section with a median distance between cores of about 20 cm. Detailed thermal and af demagnetization and further rock magnetic studies were used to determine the characteristic NRM direction for each sample. Initial NRM intensities and low field susceptibilities reflect variations in oxidation potential and sedimentation rate during carbonate deposition. The Breggia section covers an estimated 12Myr of Lower to Middle Jurassic time during which more than 60 distinct reversals of the geomagnetic field are recorded. This corresponds to a comparatively high mean reversal frequency of about 5 reversals Myr⁻¹. The Breggia polarity zonation can be correlated with the nearby section at Alpe Turati (Como, Italy) and comparable polarity patterns are recognized in other biostratigraphically well-dated magnetostratigraphic profiles from Hungary and Umbria (Italy).  相似文献   

Sulfur flows of Ra Patera,Io     

D.C. Pieri  S.M. Baloga  R.M. Nelson  Carl Sagan 《Icarus》1984,60(3):685-700

Voyager 1 imaging data have been used to investigate the color and morphology of several radial flow-like features at Ra Patera, a broad volcanic structure at approximately 8° latitude and 325° longitude on the Galilean satellite Io (J1). It was found that downstream progressions of flow color and morphology are consistent with lava of a predominately sulfur composition cooling radiatively and erupting in the range of 470 to 520°K at effusion rates at 10¹⁰ to 10¹¹ cm³/sec. This implies global resurfacing rates by volcanic flows on Io of the order of 1 cm/year. Calculated energy content and effusion rates for flows at Ra Patera, using the physical parameters of sulfur, are of the order of the largest known terrestial basaltic eruptions and are consistent with calculations of globally available energy.  相似文献   

Explosive carbon-burning nucleosynthesis     

Carl J. Hansen 《Astrophysics and Space Science》1971,14(2):389-395

Results are presented which show the final abundances of the major nuclei produced in explosive, but partial, carbon-burning taking place in a rapidly expanding medium. the effects of energy deposition due to burning and expansive cooling are taken into account explicity. The results are compatible with those obtained by other authors but show the sensitivity of the final abundances to the assumed initial conditions. A conjecture is made as to the physical site of the burning.Of the National Bureau of Standards and University of Colorado.  相似文献   

Simple Models of the Deformation of an Earth with a Fluid Core-I     

Carl Wunsch 《Geophysical Journal International》1974,39(3):413-419

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