Large Eddy Simulation for Plunge Breaker and Sediment Suspension

Breaking waves are a powerful agent for generating turbulence that plays an important role in many fluid dynamical processes, particularly in the mixing of materials. Breaking waves can dislodge sediment and throw it into suspension, which will then be carried by wave-induced steady current and tidal flow. In order to investigate sediment suspension by breaking waves, a numerical model based on large-eddy-simulation (LES) is developed. This numerical model can be used to simulate wave breaking and sediment suspension. The model consists of a free-surface model using the surface marker method combined with a two-dimensional model that solves the flow equations. The turbulence and the turbulent diffusion are described by a large-eddy-simulation (LES) method where the large turbulence features are simulated by solving the flow equations, and a subgrid model represents the small-scale turbulence that is not resolved by the flow model. A dynamic eddy viscosity subgrid scale stress model has been used for the     

ZUR STRATIGRAPHIE DES MINUSSINISCHEN PALAOZOIKUM

Whrend der geologischen Forschungen welche im Jahre 1930 imBezirk Atschinsk des Minussinischen Gebiets (Westsibirien) von R.I.Vialovadurchgeführt wurden,haben wir einige für die Stratigraphie ziemlich interessanteFunde gemacht.     

Geochronological, Geochemical and Paleomagnetic Clues for Existence of a ~2.1Ga Dyke Generation in the Mashishing Area, South Africa

正Dyke swarms are widespread throughout the Kaapvaal Craton(KC)in South Africa and have been documented in some detail.Up to date,only the~2.9 Ga SE-trending and the~2.7 to~2.66 Ga radiating dyke arrays are recognized     

Constraining the Timing of the Molopo Farms Complex Emplacement and Provenance of Its Country Rock

正The Molopo Farms Complex(MFC)is a 13000 km2layered,mafic-ultramafic intrusion straddling the southern border of Botswana with South Africa.It does not outcrop due to Cenozoic cover,but is believed to intrude the     

复合汞—锑—金矿化的空间分布特点

许多金—锑矿床的地质构造和矿物生成顺序在文献中都有描述,并且能经常遇到有关金矿化与辰砂矿化在空间共存的论述。本文研究的矿床是一个具有全部三种矿化类型显示的实例,我们认为,这些矿化类型相互之间有密切的成因联系,并具有明显的、在它们空间带状分布中表现出来的从属关系,但同时它们的赋存条件又各不相同。     

大气中二氧化碳含量的预报

以世界能源发展基本方案(其中拟尽可能利用有机燃料的代替能源)为依据,提出了五种2100年以前向大气排放二氧化碳强度的预报方案。这些方案的区别在于所利用的有机燃料中煤、石油和天然气所占的比例不同。借助碳循环模式为各个方案求得2100年以前的大气二氧化碳分压。这五个方案由于考虑了模式参数的不确定性,其预报的二氧化碳浓度范围比1985年菲拉赫会议所得结果要小。