地形坡度对多金属结核分布的控制作用   总被引：3，自引：3，他引：3  

王英  李家彪  韩喜球  吴自银 《海洋学报》2001,23(1):60-65

选取我国东太平洋多金属结核开辟区内的一个区域作为研究区,利用人工神经网络中应用最为广泛的BP网络,建立控制多金属结核分布的地质因素与多金属结核分布之间的映射关系,探讨地形坡度对多金属结核分布的控制作用.结果表明,在经度、纬度、水深、坡度四个因素中,坡度对结核分布影响程度最大;多金属结核主要分布于坡度小于5°的地方;当坡度小于5°时,丰度与地形坡度呈正相关,品位与地形坡度呈负相关,丰度与品位呈负相关;品位与坡度似呈指数关系,坡度增大,品位降低.  相似文献   

Effect of Berm Width and Elevation on Irregular Wave Run-Up     

Chen Guoping  Yu Kuang-ming  Zhang Jiachang Assistant Engineer  River  Harbour Department  Nanjing Hydraulic Research Institute  Nanjing Prof.  Senior Engineer  River  Harbour Department  Nanjing Hydraulic Research Institute  Nanjing Senior Engineer  River  Harbour Department  Nanjing Hydraulic Research Institute  Nanjing 《中国海洋工程》1991,(4)

This paper discusses the effect of berm width and elevation of composite slope on irregular wave run-up. Based on the data obtained from model tests, the formula and distribution of irregular wave run-up on composite slope are derived. The changing of wind speed, width and elevation of the berm are considered comprehensively. The wave run-up with various exceedance probability can be es-timated utilizing the distribution curves of irregular wave run-up.  相似文献   

波浪作用下岸坡和海底平衡条件的研究     

沈剑平  范德江 《中国海洋大学学报(自然科学版)》1993,(4)

提出波浪作用下岸坡和海底动态和静态平衡条件的数学模型。在已建立的推移质泥沙体积输沙率基本关系式的基础上,根据连续方程,计算出底坡、泥沙、波浪三要素在动态和静态平衡情况下的关系式,得出反映这种关系的底坡平衡函数曲线图。用实际资料对这一函数曲线进行了验证,并对实际资料相对模型的某些差异作出解释。  相似文献   

Overtopping Discharge of Wind-Waves on Simple Slope Dikes     

Yu Kuang-ming  Zhang Jiachang  Zhou Jiabao Professor  Senior Engineer  The River  Harbour Department  Nanjing Hydraulic Research Institute  Nanjing Senior Engineer  The River  Harbour Department  Nanjing Hydraulic Research Institute  Nanjing 《中国海洋工程》1991,(4)

An empirical formula for estimating the overtopping discharge of wind-waves on a smooth-impermeable-simple slope dyke is derived through model tests in this paper, it can be adopted by related design departments in the determination of the crest elevation of the dyke.  相似文献   

东营凹陷王家岗地区王古1潜山构造特征及油气成藏条件     

侯方辉  李三忠  王金铎  于建国  吕海青  许淑梅 《中国海洋大学学报(自然科学版)》2007,37(2):341-344,322

进一步了解王古1潜山的构造特征及成藏条件,利用渤海湾盆地济阳坳陷东营凹陷王家岗地区的大量三维地震剖面和一些钻井资料,并结合东营凹陷南坡缓坡带区域构造背景及成藏条件分析认为,王古1潜山初始发育于印支期,后经燕山期拉张断陷,切割为断块并抬升,最后于燕山期定型,为典型的缓坡盆倾残丘潜山。该潜山被NW向和NE向断裂切割,潜山高部位侵蚀风化严重,上覆孔店组盖层及沙河街组烃源岩,油气通过断层和不整合面运移至潜山顶部形成侵蚀残丘型油气藏。  相似文献   

规则波在缓坡上变形与破碎数值分析     

李玉成  肖辉 《海洋工程》2007,25(1):27-34

通过在二维数值水槽内用边界元法直接求解Laplace方程,对规则波在缓坡上的变形及破碎进行了数值计算。分析了不同底坡及采用不同底摩阻系数时规则波的破碎特征,并对规则波破碎的极限坡度进行了研究。重点分析了规则波破碎时海底坡度、底摩阻系数及波形不对称性对破碎指标的影响。  相似文献   

Parabolic Wave Propagation Modelling in Orthogonal Coordinate Systems     

袁德奎  林斌良肖鸿 《中国海洋工程》2004,18(3):445-456

This paper presents a numerical model study of the propagation of water waves using the parabolic approximation of the mild-slope equation in the orthogonal coordinate system. Two types of coordinate systems are studied: (a) a general form of orthogonal coordinate system and (b) the conformal system, a special form of orthogonal coordinate system. Two typical examples, namely, expanded breakwaters and a circular channel, are studied to validate the model. First, the examples are studied by use of the general orthogonal coordinates. Then the same examples are computed by use of the confonnal system. The computational results show that the confonnal coordinate system generally gives better predictions than the general orthogonal system. A numerical technique for generating the conformal grid is combined with the numerical model to improve the practicability of the model. The comparison between the result from the numerical grid system and that from the analytical grid system shows that reliable computational results can be obtained by use of the numerical confonnal grid system.  相似文献   

Channelled erosion through a marine dump site of dredge spoils at the mouth of the Puyallup River, Washington State, USA     

Neil C. Mitchell   《Marine Geology》2005,220(1-4):131-151

Channels are relatively common on river-mouth deltas, but the process by which they arise from river sediment discharge is unclear because they can potentially be explained either by negatively buoyant (hyperpycnal) flows produced directly from the river outflow or by flows generated by repeated failure and mobilisation of sediment rapidly deposited at the delta front. Channels eroded through a dump site of dredge spoils are described here from multibeam and older sonar data collected in Commencement Bay, at the mouth of the Puyallup River. Shallow channels on the seaward upper surface of the dump site, away from any flows that could have been produced by delta front failures, suggest that at least some hyperpycnal flows were produced directly from the positively buoyant river outflow up to 200 m from the edge of the river mouth platform. The form of channel bed erosion is revealed by the longitudinal shape of the main eroded channel compared with the adjacent dump site profile. It suggests that the channel evolved by its steep front retreating, rather than by simple vertical entrenchment or diffusive-like evolution of the profile, a geometry interpreted as evidence that repeated failure of the bed occurred in response to shear stress imposed by bottom-travelling flows. Model calculations based on shear strengths back-calculated from the geometry of channel wall failures suggest that, if the main channel were eroded solely by hyperpycnal flows, their generation was remarkably efficient in order to create flows vigorous enough to cause channel bed failure. Besides the sediment concentration and discharge characteristics that have been considered to dictate the ability of rivers to produce hyperpycnal flows, it is suggested that the timing of floods with respect to the tidal cycle should also be important because extreme low tides may be needed to ensure that coarse sediment is transferred vigorously to the edge of river mouth platforms.  相似文献   

陆坡非旋转重力羽状流的数值模拟          下载免费PDF全文

王凯  占全安  施心慧 《海洋科学》2007,31(7):55-62

借助MITgcm模式使用二维非静力近似在水平方向采用不等间距网格,模拟了陆坡非旋转重力羽状流的流动。模拟显示陆坡上的重力羽状流的运动比较复杂。通过数值实验,发现改变地形或调整冷源强度都会影响沿陆坡下沉的低温高密度水的羽状流形态,潮汐亦会对重力羽状流有一定的影响。经计算发现在陆坡处,Richardson数小于1/4,宜发生Kelvin-Helmholtz不稳定性,并由卷挟导致环境流体与高密度流体混合,沿着斜坡加速下滑。  相似文献   

均匀土质边坡稳定性计算的一种新方法     

单辉  葛磊 《海岸工程》2001,20(2):34-39

根据土力学原理 ,推导出一种在不考虑渗流力的情况下 ,确定斜坡临界滑动面和计算斜坡稳定系数的新方法。介绍了该方法在若干土石方工程中的应用实例。  相似文献