全文获取类型
收费全文 | 308篇 |
免费 | 14篇 |
国内免费 | 2篇 |
专业分类
测绘学 | 4篇 |
大气科学 | 26篇 |
地球物理 | 66篇 |
地质学 | 68篇 |
海洋学 | 73篇 |
天文学 | 73篇 |
自然地理 | 14篇 |
出版年
2022年 | 2篇 |
2021年 | 2篇 |
2020年 | 7篇 |
2019年 | 8篇 |
2018年 | 10篇 |
2017年 | 10篇 |
2016年 | 4篇 |
2015年 | 5篇 |
2014年 | 11篇 |
2013年 | 15篇 |
2012年 | 8篇 |
2011年 | 7篇 |
2010年 | 16篇 |
2009年 | 14篇 |
2008年 | 17篇 |
2007年 | 9篇 |
2006年 | 12篇 |
2005年 | 13篇 |
2004年 | 22篇 |
2003年 | 19篇 |
2002年 | 6篇 |
2001年 | 7篇 |
2000年 | 7篇 |
1999年 | 8篇 |
1998年 | 11篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1994年 | 4篇 |
1993年 | 2篇 |
1991年 | 3篇 |
1990年 | 4篇 |
1988年 | 4篇 |
1987年 | 2篇 |
1986年 | 4篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1981年 | 3篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 4篇 |
1976年 | 2篇 |
1975年 | 3篇 |
1974年 | 3篇 |
1973年 | 9篇 |
1972年 | 2篇 |
1971年 | 3篇 |
1970年 | 1篇 |
1969年 | 1篇 |
1968年 | 2篇 |
排序方式: 共有324条查询结果,搜索用时 234 毫秒
61.
Yoshinobu Wakata Takashi Setou Ikuo Kaneko Hiroshi Uchida Shiro Imawaki 《Journal of Oceanography》2006,62(1):25-35
The interannual variability of the Kuroshio volume transport passing through the 137°E meridian south of Japan was simulated
with an ocean general circulation model (OGCM). The time series of the Kuroshio volume transport over the 1000 m depth in
the OGCM is well reproduced by the one-dimensional quasi-geostrophic (QG) vorticity equation with a windstress forcing. In
our analysis of the OGCM and QG results, we found that peaks and troughs of the time series of the Kuroshio volume transport
with 2–3 yr time-scale were induced by windstress curl, both local and immediately eastward, whereas longer time-scale variability
was also induced by windstress curl near the dateline. 相似文献
62.
Field observation was conducted to monitor phosphate concentrations in groundwater and seawater mixing at two sandy beaches in Futtsu and Miura in Tokyo Bay, Japan. Dissolved phosphate concentrations were measured along transects from fresh groundwater aquifer to seawater adjacent the beaches. The concentrations were often high (up to 46 µM) in fresh groundwater samples (Cl– < 0.2). Coastal seawater, on the other hand, exhibited low phosphate concentrations (1.5 µM or less). Along the transects, phosphate generally displayed non-conservative behavior during mixing of fresh and saline waters in the aquifer; concentrations as high as 100 µM were found around the upper limit of seawater intrusion (Cl– = 2). Laboratory experiments were executed to identify the processes that control the phosphate behavior in the mixing processes. The results revealed that adsorption-desorption processes by the aquifer sand particles could significantly control the phosphate concentrations in the groundwater. Furthermore, the adsorption and/or desorption was found to be a function of salinity; the equilibrium concentration of dissolved phosphate in slurry of sand and water was the highest in freshwater and decreased considerably in saline water. The extreme concentration of phosphate may be caused by release from sand particles coinciding with the rapid change in salinity with tide. 相似文献
63.
Masahiro Endoh 《Journal of Oceanography》1977,33(1):6-15
A numerical study of characteristics of the front formed by cooling of the sea surface and inflow of the fresh water is made within a vertical two-dimensional plane without the rotation of the earth. The convective adjustment technique is employed to parameterize the small scale convective overturning process.A sharply edged shelf causing the marked difference of the heat capacity of the water columns between over the shelf (50 m depth) and in the deeper region (150 m depth), is responsible for the formation of a thermal front over the shelf edge and two cell circulations of the same sense with each other adjoining at the frontal region.Inflow of the fresh water at the upper region of the coast (which is equivalently replaced by the outflow of the salt from the same region) adds a circulation of the opposite sense to the above ones, which transports the water of low salinity and low temperature offshore and forms a sharp front both of temperature and salinity with the offshore water of high salinity and high temperature. This thermohaline front or Oceanic front has a remarkable character that the horizontal density gradient is minimal at the front due to the counteracting contributions of temperature and salinity to density. Response of this front to the sudden ceases of the surface cooling and the fresh water supply, is also studied in order to understand its transient behaviors. 相似文献
64.
Masahiro Endoh 《Journal of Oceanography》1973,29(4):148-154
Dynamics of western boundary currents in the subtropical and subpolar gyres are studied as a source-sink flow of barotropic fluid by means of numerical integration of the time-dependent non-linear vorticity equation. The bottom topography consists of a continental shelf of uniform slope (120 km wide) parallel to the straight western coast and a flat bottom of uniform depth. The steady solution in the case of low Reynolds number (Re≦100) shows the vorticity balance of the western boundary current between theβ-, diffusion-, and bottom relief terms. The cuspidated flow of the western boundary current in the subpolar gyre is observed as a compensating flow for the subtropical western boundary current separating from the western coast. In the case of Re=350, the zonal current separating from the coast meanders with the wave length of the stationary Rossby waves. It is shown that in the present model the separation of the boundary current is controlled by the planetary vorticity (f) of the fluid particle in the boundary flow, with which the same particle flows out the eastern wall at the corresponding latitude. The decrease of the efflux width increases the intensity of the non-linear overshooting of the boundary current separating from the western coast. 相似文献
65.
Masahiro Endoh 《Journal of Oceanography》1980,36(2):134-140
Summarized is the author's study of the ocean circulation dynamics with numerical models, for which he was honored by the
Okada Prize (1979). Cited topics are formation of the western boundary current and its variation associated with imposed wind
stress, some effects of a marine ridge on the boundary current, coastal upwelling circulation and coastal thermohaline front
formation. Recent modelling efforts in Japan, specifically on numerical study of ocean circulation dynamics are also reviewed. 相似文献
66.
To understand the behavior of manganese in diagenetic processes in sediments of an enclosed bay which is similar to those
of an estuary, chemical analyses have been carried out on both sediment and interstitial water of a core sample collected
from Tokyo Bay. The results suggest that redistribution of manganese takes place within the sediment as a result of the dissolution
of buried manganese oxides and hydroxides under reducing condition, the downward diffusion of Mn2+ through the interstitial water toward lower layers and then the precipitation of carbonate. The carbonate formed in the sediment
contains managanese carbonate probably as a solid solution between calcitic calcium carbonate and manganese carbonate. 相似文献
67.
The Japanese government is committed to resuming sustainable commercial whaling, both on the high seas and along the Japanese coastline. To this end scientific whaling programs are supported with public money and the byproducts of the catch are distributed to the public and utilized in a variety of ways. Here we review the policies which govern how these byproducts are disseminated within Japan, as well as how the population as a whole makes use of whale resources. Possibilities for the future, if and when the international moratorium on commercial whaling ends, are also discussed. 相似文献
68.
Masahiro Endoh 《Journal of Oceanography》1977,33(1):30-37
Simple numerical experiments on two-dimensional coastal upwelling are made with emphasis on the role of non-geostrophic solenoidal field of density in the formation of double-celled circulation and multi-celled density front. Geometry of shelf and slope is not taken into account. Existence of poleward undercurrent presumably caused by the longshore variation of the large scale pressure field is also suppressed for the sake of simplicity.The results are, (1) double-celled circulation revealed in the present experiment is closely related with the internal frictional layer, where the horizontal density gradient balances with the vertical gradient of the longshore velocity and the vertical diffusion of the vorticity. (2) density front formed by the emergence of the pycnocline to the sea surface is successively advected offshoreward by the Ekman transport. (3) the pycnocline intersecting the sea surface forms the density front which is nearly vertical on account of the small scale convection. The surface currents converge at the front and construct an anti-clockwise circulation (viewed from the lee side). (4) small coefficient of eddy viscosity and strong wind stress lead the Ekman transport unstable and form a multi-celled structure in the frontal region. 相似文献
69.
Spatial and temporal variations in free polyamine distributions in Uranouchi Inlet, Japan 总被引:1,自引:0,他引:1
Naoyoshi Nishibori Yukihiko Matuyama Takushi Uchida Takamitu Moriyama Yoshihiko Ogita Masumi Oda Hitoshi Hirota 《Marine Chemistry》2003,82(3-4):307-314
Polyamines are an essential component of living organisms that influence normal cell growth and development. Despite the possible importance of polyamines for marine microbial ecology, concentrations of polyamines in seawater are not well known.Using HPLC analysis with a cation exchange column and OPA reagent, we determined polyamine concentrations in seawater without carrying out desalting, concentration or derivatization steps prior to chromatography.In seawater collected from Uranouchi Inlet, putrescine and spermidine were the predominant polyamines, ranging from undetectable (N.D.) to 4.4 nM and N.D. to 2.8 nM, respectively. Though other polyamines were detected, the frequency of detection was much lower than that of putrescine and spermidine; concentrations ranged from N.D. to 0.9 nM for cadaverine, and N.D. to 3.2 nM for norspermidine. Norspermine and spermine were detected in only a few samples; their concentrations varied from N.D. to 3.2 nM and N.D. to 0.5 nM, respectively. These concentrations were higher in the summer. 相似文献
70.