全文获取类型
收费全文 | 97篇 |
免费 | 3篇 |
国内免费 | 2篇 |
专业分类
测绘学 | 2篇 |
大气科学 | 2篇 |
地球物理 | 30篇 |
地质学 | 10篇 |
海洋学 | 38篇 |
天文学 | 7篇 |
综合类 | 1篇 |
自然地理 | 12篇 |
出版年
2021年 | 2篇 |
2020年 | 1篇 |
2018年 | 4篇 |
2017年 | 2篇 |
2016年 | 3篇 |
2015年 | 1篇 |
2014年 | 1篇 |
2013年 | 3篇 |
2012年 | 2篇 |
2011年 | 5篇 |
2010年 | 3篇 |
2009年 | 4篇 |
2008年 | 10篇 |
2007年 | 4篇 |
2006年 | 3篇 |
2005年 | 10篇 |
2004年 | 3篇 |
2003年 | 5篇 |
2002年 | 4篇 |
2001年 | 3篇 |
2000年 | 1篇 |
1999年 | 2篇 |
1998年 | 1篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1981年 | 2篇 |
1979年 | 4篇 |
1978年 | 3篇 |
1977年 | 3篇 |
1975年 | 1篇 |
排序方式: 共有102条查询结果,搜索用时 156 毫秒
21.
22.
A huge hydrothermal field, named the "Hakurei Sulfide Deposit" (HSD) was discovered in the North Myojin Rift (NMR), Izu–Bonin Back-Arc Rift (BAR) during the 2003 survey cruise of R/V Hakurei-maru No.2 . This paper investigates the geotectonic features and the tectonic setting of ore deposits between the NMR and the Hokuroku Basin, which is representative of kuroko fields in Japan. The topographic features of the NMR and the Hokuroku Basin are similar. Both have a clear ring structure surrounded by faults and the east–west width is almost the same. Many kuroko deposits were formed on the extrusion centers of the five pre-mineral acidic volcanic complexes, located in a loop inside the Hokuroku Basin. In the case of the NMR, seven submarine volcanoes are also located in a loop, and the HSD formed inside the summit caldera of Bayonnaise Knoll, which is one of the seven volcanoes. These topographic similarities highlight that the NMR is a modern analog of the Hokuroku Basin. Identifying such similarities is extremely useful when prospecting kuroko deposits on land equivalents as well as on the other segments of the Izu–Bonin BAR. The probability of finding kuroko deposits on land is expected to increase when the following are identified: (i) location of back-arc rift and the volcanic front; (ii) direction of the arc–trench system and intra-rift faults (and/or fracture zone); (iii) position of submarine volcanoes surrounding a back-arc rift; and (iv) intersections of a caldera fault and intra-rift fault (and/or fracture zone) inside the summit caldera of submarine volcanoes. Within these aforementioned points a ring structure, acidic volcanic complexes that circle the circuit and submarine calderas along the volcanic front, are an important indication of submarine hydrothermal deposits. 相似文献
23.
24.
Sensitivity analysis of a coastal marine ecosystem 总被引:1,自引:0,他引:1
An ecosystem with four compartments, i.e. PO4-P, phytoplankton, zooplankton and detritus, in a coastal region was considered. Sensitivity analysis of a phosphorus flow model in well-mixed water without currents concludes that (1) the maximal photosynthetic rate,V
m
, in Michaelis-Menten relation plays an important role in the distribution of biomass among compartments but the half saturation constant,K
s
, is not so important, (2) the natural death rate of phytoplankton is important for the ecosystem, (3) the natural death rate of zooplankton is also effective on the ecosystem.A numerical experiment was also performed on the ecosystem with four compartments are also studied using a dynamical barotropic model of tidal currents of Mikawa Bay (Japan). Diffusion coefficient in diffusion equation plays the role of a linear smoothing parameter in the horizontal distribution of compartment. On the other hand, perturbations of biological parameters cause nonlinear variations in the horizontal distribution of compartment. 相似文献
25.
26.
A criterion for the stability of plankton patchiness is developed using a Liapunov function. Plankton growth, advection and diffusion in a closed area are considered. A critical length scale for the stability does not exist but a more common criterion which contains the growth rateα, diffusion coefficientA l and arbitrary function of growthf can be introduced in an integral form. 相似文献
27.
28.
From frequent field observations performed in coastal waters around the Izu Islands, Japan, a clear regional upwelling associated with the wind was detected baside Niijima Island. Nutrient supply by the upwelling into the euphotic zone was confirmed, and the subsequent phytoplankton growth supported by the upwelled nutrients was evaluated. The upwelling and the nutrient supply occurred within a day over an area ofca. 400 km2, and phytoplankton growth response occurred only a few days after the upwelling. Such regional upwelling is considered to be one of the major mechanisms supporting the high productivity of coastal waters.Contribution number 423 from the Shimoda Marine Research Center, University of Tsukuba. 相似文献
29.
Michio Kawamiya 《Journal of Oceanography》2002,58(2):365-378
A review of ecosystem modeling is presented, classifying the models on the basis of the problems they address. The problems
are chosen mainly from those concerning the North Pacific and encompass: limiting factors in high-nutrient/low-chlorophyll
(HNLC) regions; nutrient supply to the subtropical gyre; long-term variation; parameter optimization; oceanic provinces. A
future research direction should be to sort out priorities of various biogeochemical and ecological processes with the long-term
variation problem being the axis, while keeping the model complexity at a minimum and invoking the parameter optimization
technique.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
30.
Akio Ishida Kisaburo Nakata Shigeaki Aoki Hiroshi Kutsukake Michio J. Kishi Masahisa Kubota 《Journal of Oceanography》2001,57(4):433-450
Distributions and characteristics of water mass and chlorofluorocarbons (CFCs) in the North Pacific are investigated by using
a General Circulation Model (GCM). The anthropogenic CO2 uptake by the ocean is estimated with velocity fields derived from the GCM experiments. The sensitivity of the uptake to
different diffusion parameterizations and different surface forcing used in the GCM is investigated by conducting the three
GCM experiments; the diffusive processes are parameterized by horizontal and vertical eddy diffusion which is used in many
previous models (RUN1), parameterized by isopycnal diffusion (RUN2), and isopycnal diffusion and perpetual winter forcing
for surface temperature and salinity (RUN3). Realistic features for water masses and CFCs can be simulated by the isopycnal
diffusion models. The horizontal and vertical diffusion model fails to simulate the salinity minimum and realistic penetration
of CFCs into the ocean. The depth of the salinity minimum layer is better simulated under the winter forcing. The results
suggest that both isopycnal parameterization and winter forcing are crucial for the model water masses and CFCs simulations.
The oceanic uptake of anthropogenic CO2 in RUN3 is about 19.8 GtC in 1990, which is larger by about 10% than that in RUN1 with horizontal and vertical diffusive
parameterization. RUN3 well simulates the realistic water mass structure of the intermediate layer considered as a candidate
of oceanic sink for anthropogenic CO2. The results suggest that the previous models with horizontal and vertical diffusive parameterization may give the oceanic
uptake of anthropogenic CO2 underestimated.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献