全文获取类型
收费全文 | 133篇 |
免费 | 7篇 |
国内免费 | 25篇 |
专业分类
测绘学 | 22篇 |
大气科学 | 7篇 |
地球物理 | 26篇 |
地质学 | 18篇 |
海洋学 | 78篇 |
天文学 | 6篇 |
综合类 | 5篇 |
自然地理 | 3篇 |
出版年
2021年 | 1篇 |
2020年 | 5篇 |
2019年 | 6篇 |
2018年 | 3篇 |
2017年 | 7篇 |
2016年 | 4篇 |
2015年 | 7篇 |
2014年 | 7篇 |
2013年 | 9篇 |
2012年 | 9篇 |
2011年 | 5篇 |
2010年 | 6篇 |
2009年 | 11篇 |
2008年 | 8篇 |
2007年 | 12篇 |
2006年 | 11篇 |
2005年 | 3篇 |
2004年 | 4篇 |
2003年 | 14篇 |
2002年 | 6篇 |
2001年 | 6篇 |
2000年 | 4篇 |
1999年 | 1篇 |
1998年 | 5篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1989年 | 1篇 |
1980年 | 1篇 |
排序方式: 共有165条查询结果,搜索用时 0 毫秒
161.
A two-dimensional numerical model was presented for the simulation of wave breaking, runup and turbulence in the surf and swash zones. The main components of the model are the Reynolds-Averaged Navier–Stokes equations describing the average motion of a turbulent flow, a k–ε turbulence closure model describing the transformation and dissipation processes of turbulence and a volume of fluid technique for tracking the free surface motion. Nearshore wave evolution on a sloping bed, the velocity field and other wave characteristics were investigated. First, the results of the model were compared with experimental results for different surf zone hydrodynamic conditions. Spilling and plunging breakers were simulated and the numerical model investigated for different wave parameters. The turbulence field was also considered and the spatial and time-dependent variations of turbulence parameters were discussed. In the next stage of the study, numerical results were compared with two sets of experimental data in the swash zone. Generally, there is good agreement except for turbulence predictions near the breaking point where the model does not represent well the physical processes. On the other hand, turbulence predictions were found to be excellent for the swash zone. The model provides a precise and efficient tool for the simulation of the flow field and wave transformations in the nearshore, especially in the swash zone. The numerical model can simulate the surface elevation of the vertical shoreline excursion on sloping beaches, while swash–swash interactions within the swash zone are accounted for. 相似文献
162.
The flow characteristics of tidal jets induced by a Tidal-Jet Generator (TJG) are investigated using a finite-difference numerical scheme, named Navier–Stokes (NS)–Marker and Cell (MAC)-TIDE, based on the fully 3D NS equations. The TJG is an enclosed rectangular breakwater, which has vertical opening and a large enclosed volume inside. During both phases of tide, strong and uni-directional jets can be obtained locally from the inlet of the TJG, due to the water level difference between the inner and outer sides of TJG.The computed results are extensively compared with three other independently developed numerical models; 3D-ADI, DVM, and CIP-CSF. These models are based on quasi-3D, 2D depth-averaged, and fully 3D NS equations, respectively. It is seen that the present fully 3D numerical model NS–MAC-TIDE can predict the maximum intensity of inlet velocity with higher accuracy than the other numerical models when compared with the empirical function proposed from the experiments. The numerical simulations based on NS–MAC-TIDE can reproduce successfully the processes of generation, development, and dissipation of tidal jets. The effects of gap opening on the main characteristics of the tidal jet flow are assessed. Through numerical assessment, it is also clearly demonstrated that the residual time of a pollutant distributed around the front of the TJG can be decreased by significant amount due to the locally induced tidal jet. The TJG can thus utilize tidal energy for water purification in local marine environment by providing a flushing mechanism. 相似文献
163.
F. J. Jorissen I. Wittling J. P. Peypouquet C. Rabouille J. C. Relexans 《Deep Sea Research Part I: Oceanographic Research Papers》1998,45(12):2157-2188
Live (Rose-Vengal stained) benthic foraminifera were studied along a transect across the main area of organic matter deposition in the Cape Blanc upwelling region. The faunal analyses suggest that at the shallowest station (1200 m) the benthic ecosystem is permanently influenced by the upwelling, whereas at the deepest stations (3010 and 2530 m depth) the ocean bottom is subject to significant organic influxes only in summer. The vertical zonation of foraminiferal species in the sediment shows a close correspondence with the depth distribution of oxic respiration, nitrate and sulphate reduction. It is suggested that this linkage is caused by the presence of various stocks of anaerobic and sulphate- and nitrate-reducing bacteria. Deep infaunal foraminiferal species are thought to feed selectively, either on the bacterial stocks or on nutritious particles produced by bacterial degradation of more refractory organic matter. As such, foraminiferal microhabitats are only indirectly controlled by pore water oxygen concentrations. 相似文献
164.
165.