The new model of a tidally disrupted star: further development and relativistic calculations     

P. B. Ivanov  M. A. Chernyakova  I. D. Novikov 《Monthly notices of the Royal Astronomical Society》2003,338(1):147-155

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Fluctuation analysis of the far-infrared background – information from the confusion     

Yasmin Friedmann  François Bouchet 《Monthly notices of the Royal Astronomical Society》2004,348(3):737-744

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Scaling Laws in Self-Gravitating Discs     

D. Huber  D. Pfenniger 《Astrophysics and Space Science》2001,276(2-4):523-530

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Influence of submerged aquatic vegetation on size class distribution of perch (Perca fluviatilis) and roach (Rutilus rutilus) in the littoral zone of Lake Geneva (Switzerland)     

Olivier Rossier  Emmanuel Castella  Jean-Bernard Lachavanne 《Aquatic Sciences - Research Across Boundaries》1996,58(1):1-14

The abundance of different size classes of perch and roach in the littoral zone of Lake Geneva was compared between submerged aquatic vegetation and unvegetated zones. Samples were taken with gillnets during four periods between June and October 1993. During the vegetation period (June to September), perch 9 cm and roach 10 cm were more abundant in vegetation whereas roach > 20 cm were more abundant in open water. Perch larger than 18 cm and medium roach were equally distributed in both habitats whatever the period, whereas medium perch distribution fluctuated according to the period. In October, after the decline of the vegetation, no more differences in fish distribution were observed except for small roach, which were always more abundant in the vegetated sites.  相似文献   

Influence of water eutrophication on the macrophytic vegetation of Lake Lugano     

J. -B. Lachavanne  J. Perfetta  R. Juge 《Aquatic Sciences - Research Across Boundaries》1992,54(3-4):351-363

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The role of sediments in the phosphorus cycle in Lake Lugano. I. Geochemical approach     

D. Span  J. Dominik  M. A. Lazzaretti  J. -P. Vernet 《Aquatic Sciences - Research Across Boundaries》1992,54(3-4):277-284

The bottom sediment from three coring stations in Lake Lugano (Lago di Lugano) show major differences in their role in the P-cycles related to their geochemistry and characteristics of sedimentation. In the northern basin, the deepest sediment may be considered practically inactive, due to a permanently reduced condition at the sediment-water interface. In the southern basin, the sediments are active with respect to P-recycling with strong seasonal variations. One of the sites (Figino) behaves as a sink for P due to a high iron content and an important rate of detrital sedimentation.  相似文献   

Fluid salinities obtained by infrared microthermometry of opaque minerals: Implications for ore deposit modeling — A note of caution     

Robert Moritz   《Journal of Geochemical Exploration》2006,89(1-3):284

Infrared microthermometry of opaque minerals has revealed that temperatures of phase changes vary with the infrared light source intensity, resulting in an overestimate of fluid salinities and an underestimate of homogenization temperatures. Failing to recognize this analytical artifact during infrared microthermometry may result in meaningless geological models. A fluid inclusion investigation on enargite from a high-sulfidation epithermal deposit is used as an example to document this. Fluid salinities obtained during an early investigation ranged between 6.3 and 20.4 wt.% NaCl, which were interpreted as intense boiling or as evidence for the involvement of a magmatic brine during ore formation. Fluid inclusion salinities obtained with improved analytical settings, i.e. low light intensities, fall between 1.1 and 1.7 wt.% NaCl and are in better agreement with fluid salinities obtained in quartz from similar deposits, and recent modeling suggesting vapor transport of Au and Cu from deep porphyry-Cu environments to shallower high-sulfidation epithermal deposits.  相似文献   

Dissolved silica budget in the North basin of Lake Lugano     

Annette Hofmann  Didier RoussyMontserrat Filella 《Chemical Geology》2002,182(1):35-55

We studied the dissolved silica cycle in the water column of the North basin of Lake Lugano, Switzerland/Italy. Lake Lugano is a meromictic, eutrophic lake, permanently stratified below 100-m depth. A one-box model was used to calculate a silica mass-balance over 1993, based on various lake measurements, such as sediment traps, sediment cores, water analysis and biota countings. We found that the North basin of Lake Lugano is at steady state as far as dissolved silica is concerned. The primary source of dissolved silica in the lake is river input (about 80%), with diffusion from bottom sediments and groundwater input also playing a role. Atmospheric input is negligible. The main export of dissolved silica occurs via biogenic uptake by diatoms and final burial of their frustules in the bottom sediment. Loss of dissolved silica through the lake outflow only represents 15% of the total output. Of the total amount of Si exported to the lake bottom through diatom sinking, less than 20% is re-supplied to the surface water by diffusion. Thus, the lake acts as an important permanent sink for silica. The long residence time of dissolved silica in the lake (7 years) is related to the strong physical stratification of the lake. Only about 10% of the standing stock are available to phytoplankton uptake.  相似文献   

Forced Evictions in Tropical Cities: An Introduction     

Kris Olds  Tim Bunnell  & Scott Leckie 《Singapore journal of tropical geography》2002,23(3):247-251

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华南中尺度暴雨数值预报的不确定性与集合预报试验   总被引：50，自引：0，他引：50  

陈静  薛纪善  颜宏 《气象学报》2003,61(4):432-446

利用非静力MM5模式,分析了不同积云对流参数化方案对华南暖区暴雨数值预报的不确定性影响,进行了中尺度暴雨模式扰动集合预报试验。不同对流参数化方案的对流凝结加热引起不同的局地温度扰动,通过大气内部的热力动力过程,导致垂直速度的差异,进而影响网格尺度和次网格尺度降水时间、地点和强度。后续降水再通过凝结潜热释放形成新的扰动源。不同积云对流参数化方案还可引起扰动源能量传播方式不同,最终使模拟大气的动力和热力结构有差异。针对物理过程的不确定性,使用两种模式扰动方法构造集合预报扰动模式,第一种方法是随机组合不同积云对流参数化方案和边界层方案,第二种方法是扰动Grell积云对流参数化方案中主要参数振幅。集合预报结果表明,第一种方法的集合预报效果优于第二种方法,仅扰动参数振幅值似乎还不足以反映华南暴雨预报的不确定性。单一的确定性预报在暴雨落区和强度方面的可信度不稳定,集合产品能给华南暴雨过程提供更有用价值的指导预报,具有较高的应用价值。  相似文献