Influence of model conceptualisation on one-dimensional recharge quantification: Uley South,South Australia     

Carlos M. Ordens  Vincent E. A. Post  Adrian D. Werner  John L. Hutson 《Hydrogeology Journal》2014,22(4):795-805

Model conceptualisation is a key source of uncertainty in one-dimensional recharge modelling. The effects of different conceptualisations on transient recharge predictions for the semi-arid Uley South Basin, South Australia, were investigated. One-dimensional unsaturated zone modelling was used to quantify the effect of variations of (1) lithological complexity of the unsaturated zone, and (2) representation of preferential flow pathways. The simulations considered ranges of water-table depths, vegetation characteristics, and top soil thicknesses representative for the study area. Complex lithological profiles were more sensitive to the selected vegetation characteristics and water-table depth. Scenarios considering runoff infiltration into, and preferential flow through sinkholes resulted in higher and faster recharge rates. A comparison of modelled and field-based recharge estimates indicated that: (1) the model simulated plausible recharge rates, (2) only the models with preferential flow correctly reproduced the timing of recharge, and (3) preferential flow is probably redistributed in the unsaturated zone rather than passing to the water table directly. Because different but equally plausible conceptual models produce widely varying recharge rates, field-based recharge estimates are essential to constrain the modelling results.  相似文献   

UV spectroscopy of the hot bare stellar core H1504+65 with the HST Cosmic Origins Spectrograph     

K. Werner  T. Rauch 《Astrophysics and Space Science》2011,335(1):121-124

We present new ultraviolet spectra of the hottest known, peculiar white dwarf H1504+65, obtained with the Cosmic Origins Spectrograph on the Hubble Space Telescope. H1504+65 is the hottest known white dwarf (T _eff=200 000 K) and has an atmosphere mainly composed by carbon and oxygen, augmented with high amounts of neon and magnesium. This object is unique and the origin of its surface chemistry is completely unclear. We probably see the naked core of either a C–O white dwarf or even a O–Ne–Mg white dwarf. In the latter case, this would be the first proof that such white dwarfs can be the outcome of single-star evolution. The new observations were performed to shed light on the origin of this mysterious object.  相似文献   

World space observatory-ultraviolet among UV missions of the coming years     

Boris Shustov  Mikhail Sachkov  Ana I. Gómez?de?Castro  Klaus Werner  Norbert Kappelmann  Alexander Moisheev 《Astrophysics and Space Science》2011,335(1):273-282

Continuous access to the UV domain has been considered of importance to astrophysicists and planetary scientists since the mid-sixties. However, the future of UV missions for the post-HST era is believed by a significant part of astronomical community to be less encouraging. We argue that key science problems of the coming years will require further development of UV observational technologies. Among these hot astrophysical issues are: the search for missing baryons, revealing the nature of astronomical engines, properties of atmospheres of exoplanets as well as of the planets of the Solar System etc. We give a brief review of UV-missions both in the past and in the future. We conclude that UV astronomy has a great future but the epoch of very large and efficient space UV facilities seems to be a prospect for the next decades. As to the current state of the UV instrumentation we think that this decade will be dominated by the HST and coming World Space Observatory-Ultraviolet (WSO-UV) with a 1.7 m UV-telescope onboard. The international WSO-UV mission is briefly described. It will allow high resolution/high sensitivity imaging and high/low resolution spectroscopy from the middle of the decade.  相似文献   

Redefinition of the crater-density and absolute-age boundaries for the chronostratigraphic system of Mars     

S.C. Werner  K.L. Tanaka 《Icarus》2011,215(2):603-607

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A review of seawater intrusion and its management in Australia   总被引：5，自引：3，他引：2  

Adrian D. Werner 《Hydrogeology Journal》2010,18(1):281-285

Extended periods of below-average rainfall combined with a rising population density in the Australian coastal margin have led to higher stresses on coastal water resources, and the risk of seawater intrusion has increased. Despite reports of seawater intrusion in the majority of states and evidence that some Australian coastal aquifers are seriously depleted, comprehensive seawater intrusion investigations have only been completed for coastal systems in Queensland and to a lesser degree in Western Australia and South Australia. The degree of assessment appears to be linked to the perceived economic value of the groundwater resource. The most detailed studies include those of the Pioneer Valley and Burnett basins in Queensland, for which conceptual and mathematical models have been developed at the regional scale, and have been used to underpin trigger-level management approaches to protect against further seawater intrusion. Historical responses to seawater intrusion include the establishment of artificial recharge schemes; the most prominent being that of the Lower Burdekin aquifers in Queensland. Recommendations for future solutions include enhanced fit-for-purpose seawater intrusion monitoring, continuing research into investigation methods, and improved knowledge-sharing through education programs and the development of national guidelines for seawater intrusion assessment and management.  相似文献   

Sponges (Porifera) as living metazoan witnesses from the Neoproterozoic: biomineralization and the concept of their evolutionary success     

Xiaohong Wang  Shixue Hu  Lu Gan  Matthias Wiens  Werner E.G. Müller 《地学学报》2010,22(1):1-11

The emergence of the Metazoa can be dated back to the Neoproterozoic Era which comprises the Cryogenian Period during which two major glaciations occurred, the Sturtian and the Varanger-Marinoan. At that time, the phylum Porifera (sponges) evolved as the first animals and developed a hard skeleton. The two classes of siliceous sponges, the Hexactinellida and the Demospongiae, are already provided with the major genetic repertoire and gene regulatory networks that also exist in modern multicellular animals. Besides these metazoan innovations, the siliceous sponges display one autapomorphic character, silicatein, an enzyme which mediates bio-silica formation. Well preserved siliceous sponge fossils have been excavated from the Cambrian Burgess Shale- and Chengjiang deposits. It is concluded that it was the hard skeleton of the siliceous sponges that contributed to the successful evolution and survival of the Porifera during the last 500 Ma.  相似文献   

The Cretaceous of the Eastern Bangong-Nujiang Suture Zone (Tibet):Tectono-Sedimentation     

Pujun Wang  Frank Mattern  Werner Schneider  Wanzhu Liu  Shikai Li  Cai Li 《东北亚地学研究》2003,(1)

1IntroductionThe Tibet plateau consists of terranes which were accreted in a southward-younging succession from Late Permian to Mid-Eocene (Dewey etal., 1988; Mattern etal., 1998; Mattern and Schneider, 2000). The Songpan-Ganzi terrane was accreted to the Kunlun during Late Permian along Kunlun-Qin-ling suture. The Qiangtang block was added onto the Songpan-Ganzi terrane at the Jinsha suture dur-ing Late Triassic-Early Jurassic. The Lhasa block became attached to the Qia…  相似文献   

Alto Bkachner (Hrsg.): G. F. Brander 1713- 1783. Wissenschaftliche Instrumente aus seiner Werkstatt. Deutsches Mu-seum München. München 1983. 395 Seiten     

Werner Bronkalla 《Astronomische Nachrichten》1985,306(5):282-282

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