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181.
Hiroshi Takeda 《Journal of Oceanography》1984,40(6):410-415
Waves which propagate along a vertical wall lying in an arbitrary direction on aβ-plane are derived as a generalization of Haurwitz waves (Haurwitz, 1940) whose direction of propagation is restricted to
the east-west direction. The waves are classified into two types. One consists of neutral waves, which correspond to a generalization
of Haurwitz waves. The other consists of waves with complex wavenumber and without energy flux. The phase of the waves also
propagates in the direction normal to the coast in an envelope except for the case in which the coast lies in the east-west
direction. 相似文献
182.
Hiroshi Takeda 《Journal of Oceanography》1984,40(6):432-436
Topographically trapped (subinertia) waves that propagate along a coast lying in an arbitrary direction on aβ-plane are studied. It is found that the waves also propagate in the direction normal to the coast within an envelope due
to theβ-effect. The dispersion relation is hardly affected by theβ-effect except in a long wavelength or long period range in which generalized Haurwitz waves (Takeda, 1984b) exist. In the
long wavelength or long period range, two types of waves exist: topographically trapped type waves and generalized Haurwitz
type waves. 相似文献
183.
In the previous study, merged sea surface temperature (SST) dataset called “New Generation SST” has been produced from several
infrared and microwave satellite SSTs through an objective mapping. Here we examine the merged SST by comparison with moored
buoy SST at 1 m depth, which is treated as true sea surface temperature. Comparison between wavelet spectra of merged and
buoy SSTs shows that the former have larger amplitudes than those of the latter, which is partly explained as an aliasing
effect due to TRMM Microwave Imager (TMI) aboard Tropical Rainfall Measuring Mission (TRMM) sampling on merged products. Coherency
between wavelet-decomposed merged and buoy SSTs has high values in autumn and low ones in winter to spring. In winter, phase
differences between them are positive, meaning that wavelet components of merged SST lag those of buoy SST. Reasons for delay
and low coherency are: (1) seasonal components of merged SSTs are strongly affected by a lack of infrared SSTs due to clouds
in winter, and (2) small-scale oceanic features, undetectable by coarse-resolution microwave SSTs, are blurred by the merging
process. Improvements of merging methodology are discussed with regard to present study results. 相似文献
184.
By synthesizing data of the turbulent structure beneath wind waves in laboratory tanks, with some re-analyses, we propose the existence of a particular turbulent boundary layer which is directly coupled with wind waves, a downward-bursting boundary layer (DBBL) in water beneath wind waves. The data set indicates that the depth of this layer is from 3 to 7, or about 5 times the significant wave height of wind waves. The data observed in laboratory tanks agree with data of acoustic observations of bubble clouds under breaking wind waves in the sea made by Thorpe (1986, 1992). It is inferred that DBBL is formed in equilibrium with the local wind waves, as a common feature from initially generated wind waves, young laboratory wind waves to mature wind waves in the sea. 相似文献
185.
Takashi Ishimaru Hirotaka Otobe Toshiro Saino Hiroshi Hasumoto Toshisuke Nakai 《Journal of Oceanography》1984,40(3):207-212
A realtime monitoring system for observing physical, biological, and optical oceanographic parameters in shallow waters was developed. It consists of a CTD with oxygen sensor, anin situ fluorometer, anin situ transmissometer, and anin situ quanta meter together with an on-deck quanta meter. The system is also equipped with a water sampling device. Water sampling can be done during the upward cast on the basis of depth profiles of temperature, salinity, oxygen,in situ fluorescence, transmittance, and underwater irradiance taken during the downward cast. 相似文献
186.
The tidal current in Kagoshima Bay is simulated by the two-dimensional subdomain finite-element method. At the open boundary, the sea level is forced to be oscillatory with a linear combination of the four harmonic constituents (M2, S2, K1, O1) of the tide. A calculation having only M2 sea level at the open boundary is also performed and the harmonic constants of M2 are compared with those calculated by the four components.In the calculated velocity vector, a large difference between the two maxima or the two minima in one day appears when the vector is directed to the open sea. On the other hand, when it is directed into the bay, the two extreme velocities are almost equal. In tide-killer residual flow, the flow pattern is almost independent of the tidal age; however, the absolute value of the current velocity depends on the tidal age. The pattern is nearly the same as that calculated by giving only M2 sea level at the open boundary.In relation to the nonlinear interaction, the kinetic energy ratio KER is defined by the ratio of kinetic energy of the induced harmonic components to that of harmonic constituents given at the open boundary. KER is large where the tidal current is disturbed by obstacles,e.g. along the west coast at the mouth of the bay and in the southern sea of Mt. Sakurajima. The distribution of KER seems to be independent of the number of harmonic constituents (one or four) given at the open boundary. The difference of kinetic energy of the M2 tidal constituent between the two calculations.i.e. with the open boundary conditions of four components (M2, S2, K1, O1) and of a single component (M2), is found to be large where the current velocity is large. 相似文献
187.
The microwave backscattering from wind-wave surfaces is observed in a windwave tunnel under various conditions of the wind and wind waves, and its statistical features are investigated. The dependence of the backscattered power on the wind speed and the incident angle shows similar features to those predicted by models proposed previously. However, the dependence of the backscattered power on the incident angles also corresponds to the asymmetrical feature of the wind-wave surfaces with respect to the wind direction. The spectral analyses of time series of the backscattered intensity show that the propagating speed of fine structures of the wind-wave surface contributing to the backscattering at large incident angles does not coincide with the phase speed of the freely propagating Braggwaves. Atupwind incidence, the surface structures of wind waves contributing to the backscattering propagates with the dominant waves at their phase speed. This result is inconsistent with the two-scale model in which the Bragg waves are simply superimposed on longer waves, but is consistent with the results of optical observation by Ebuchiet al. (1987). At downwind incidence, the propagating speed is slower than the phase speed of the dominant waves. 相似文献
188.
Quantitative data on the vertical distribution and biomass of microzooplankton are presented for the western subtropical Pacific west of the Bonin Islands in winter. Microzooplankton other than foraminifera and radiolarians showed similar vertical distribution to chlorophylla. Among microzooplankters, naked ciliates, tintinnids and copepod nauplii were dominant components both in number and volume. Naked ciliates were the most dominant, comprising 82.2 % and 47.7 % of the total microzooplankton by number and volume, respectively. Copepod nauplii, occupying less than 10 % by number, accounted for 35.7 % of the volume of all microzooplankton. Tintinnids contributed less to the microzooplankton standing crop, 12.6 % of the total by number and 17.3 % by volume. Calculated microzooplankton wet weight varied from 0.84 to 1.80 g m?2 and corresponded to 9.9–18.1 % of net zooplankton weight. The relative abundance of microzooplankton to net zooplankton in this study is comparable to that previously reported in the tropical and subtropical Pacific Ocean, but a little higher than in oceanic subarctic areas. 相似文献
189.
Sea surface temperature observation by Global Imager (GLI)/ADEOS-II: Algorithm and accuracy of the product 总被引:1,自引:0,他引:1
Futoki Sakaida Kohtaro Hosoda Masao Moriyama Hiroshi Murakami Akira Mukaida Hiroshi Kawamura 《Journal of Oceanography》2006,62(3):311-319
A sea surface temperature (SST) retrieval algorithm for Global Imager (GLI) aboard the ADEOS-II satellite has been developed.
The algorithm is used to produce the standard SST product in the Japan Aerospace Exploration Agency (JAXA). The algorithm
for cloud screening is formed by combinations of various types of tests to detect cloud-contaminated pixels. The combination
is changed according to the solar zenith angle, which enables us to detect clouds even in the sun glitter region in daytime.
The parameters in the cloud-detection tests have been tuned using the GLI global observations. SST is calculated by the Multi-Channel
SST (MCSST) technique from the detected clear pixels. Using drifting buoy measurements, match-up data are produced to derive
the coefficients of the MCSST equations and to examine their performance. The bias and RMSE of the GLI SST are 0.03 K and
0.66 K for daytime and, −0.01 K and 0.70 K for nighttime, respectively. 相似文献
190.
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