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31.
Precipitation samples were collected by filtrating bulk sampler in Kitakyushu City, Japan, from January 1988 to December 1990. Volume weighted annual mean of pH was 4.93, but the pH distribution indicated that most probable value lay in the range pH 6.0–6.4. Volume weighted annual mean concentrations of major ionic components were as follows; SO
4
2–
: 84.2, NO
3
–
: 28.1, Cl–: 86.3, NH
4
+
: 45.5, Ca2+: 63.3, Mg2+: 27.0, K+: 3.4, Na+: 69.0 µ eq l–1. The highest concentrations of these ionic components were observed in winter and the lowest occurred in the rainy season. The ratio of ex-SO
4
2–
/NO
3
–
exhibited the lowest ratio in summer, and the highest ratio in winter. Good correlations were obtained between Cl– and Na+, ex-SO
4
2+
and ex-Ca2+, NO
3
–
and ex-Ca2+, and NH
4
+
and ex-SO
4
2–
, respectively. However, no correlation between Cl– and Na+ with Ca2+ was observed. The relationship of H+ with (ex-SO
4
2–
+ NO
3
–
) - (ex-Ca2+ + NH
4
+
) indicated positive correlation. 相似文献
32.
The chemical composition and D/H,
and
ratios have been determined for the acid hot waters and volcanic gases discharging from Zaō volcano in Japan. The thermal springs in Zaō volcano issue acid sulfate-chloride type waters (Zaō) and acid sulfate type waters (Kamoshika). Gases emitted at Kamoshika fumaroles are rich in CO2, SO2 and N2, exclusive of H2O. Chloride concentrations and oxygen isotope data indicate that the Zaō thermal waters issue a fluid mixture from an acid thermal reservoir and meteoric waters from shallow aquifers. The waters in the Zaō volcanic system have slight isotopic shifts from the respective local meteoric values. The isotopic evidence indicates that most of the water in the system is meteoric in origin. Sulfates in Zaō acid sulfate-chloride waters with δ34S values of around +15‰, are enriched in 34S compared to Zaō H2S, while the acid sulfate waters at Kamoshika contain supergene light sulfate (δ34S = + 4‰) derived from volcanic sulfur dioxide from the volcanic exhalations. The sulfur species in Zaō acid waters are lighter in δ34S than those of other volcanic areas, reflecting the difference in total pressure. 相似文献
33.
34.
35.
Strain and tilt changes measured during a water injection experiment at the Nojima Fault zone, Japan 总被引:2,自引:0,他引:2
Kunio Fujimori Hiroshi Ishii Atsushi Mukai Shigeru Nakao Shigeo Matsumoto Yasuhiro Hirata 《Island Arc》2001,10(3-4):228-234
Abstract In order to make geophysical and geological investigations of the Nojima Fault on Awaji Island, Japan, three boreholes measuring 1800 m, 800 m and 500 m deep were drilled into the fault zone. The fault is one of the seismic source faults of the 1995 Hyogo-ken Nanbu earthquake of M 7.2. A new multicomponent borehole instrument was installed at the bottom of the 800 m borehole and continuous observations of crustal strain and tilt have been made using this instrument since May 1996. A high-pressure water injection experiment within the 1800 m borehole was done in February and March 1997 to study the geophysical response, behavior, permeability, and other aspects of the fault zone. The injection site was located approximately 140 m horizontally and 800 m vertically from the instrument. Associated with the water injection, contraction of approximately 0.7 × 10−7 str (almost parallel to the fault) and tilt of approximately 1 × 10-7 rad in the sense of upheaval toward the injection site were observed. In addition to these controlled experiments, the strainmeter and tiltmeter also recorded daily variations. We interpret strain and tilt changes to be related to groundwater discharge and increased ultra-micro seismicity induced by the injected water. 相似文献
36.
Su Young Lee Masatsugu Ohnishi Yasuhiro Shibata Makoto Wwatanabe Kenichi Hoshino Mayumi Jige Xiangping Gu Hitoshi Chiba Tamotsu Oomori Kantaro Fujioka Peter A. Rona 《Resource Geology》2001,51(1):63-68
Abstract: Pyrite rich in Zn, up to 3.1 wt%, was found in the TAG active mound of the TAG hydrothermal field, the slow-spreading Mid-Atlantic Ridge at 26°08'N and 44°49'W. The Zn-rich pyrite is characterized by an optical homogeneity, a homogeneous distribution of Zn in the back-scattered electron images, both at a magnification of about 500, a negative correlation between Fe and Zn contents of the pyrite and a rather small unit cell edge (a0 = 5.4117 ± 0.0008Å), strongly indicating that the detected Zn is present in the pyrite in solid solution. Such Zn concentrations are observed exclusively in dendritic pyrite, suggesting that the Znrich pyrite grew from hydrothermal fluids of a high degree of supersaturation due to quenching on the seafloor. 相似文献
37.
Taku Tada Yoshinobu Tsuji Masahito Tsukamoto Yoshikazu Ueno Masayuki Kawashima Takashi Egawa Yasuhiro Yamazaki 《Pure and Applied Geophysics》1992,138(2):309-322
We carried out observations of sea-level fluctuations simultaneously at three stations on the coast of Heda Bay, Honshu, Japan, using supersonic-type water level gauges controlled by a personal computer. Analyses of the obtained data showed predominant spectral peaks at periods of 7.6, 2.0 and 1.3 minutes for all three stations. Comparison of the observed data with numerically calculated normal oscillation modes of the bay indicates that these three spectral peaks correspond to the theoretical first, third and seventh normal modes of the basin respectively, judging from the results of cross-spectral analyses. The reason for the absence of the remaining normal modes, especially of the second or the lateral first mode of the basin, is briefly considered. 相似文献
38.
Miscellaneous information 相似文献
39.
GIS-based spatial and temporal prediction system development for regional land subsidence hazard mitigation 总被引:3,自引:0,他引:3
An integrated GIS-based approach for establishing a spatial and temporal prediction system for groundwater flow and land subsidence is proposed and applied to a subsidence-progressed Japanese coastal plain. Various kinds of fundamental data relating to groundwater flow and land subsidence are digitized and entered into a GIS database. A surface water hydrological cycle simulation is performed using a GIS spatial data operation for the entire plain, and the spatial and temporal groundwater infiltration quantity is hereby obtained. Through the data transformation from the GIS database to a groundwater flow code (MODFLOW), a 3D groundwater flow model is established and unsteady groundwater flow simulation for the past 21 years is conducted with results which compare satisfactorily with observed results. Finally, a Visual Basic code is developed for land subsidence calculations considering aquifer and aquitard deformation. Future land subsidence in the plain is predicted assuming different water pumping scenarios, and the results provide important information for land subsidence mitigation decision-making. 相似文献
40.
Diffuse Emission of CO2 from Showa-Shinzan, Hokkaido, Japan: A Sign of Volcanic Dome Degassing 总被引:1,自引:0,他引:1
Pedro A. Hernández Kenji Notsu Hiromu Okada Toshiya Mori Masanori Sato Francisco Barahona Nemesio M. Pérez 《Pure and Applied Geophysics》2006,163(4):869-881
Two soil CO2 efflux surveys were carried out in September 1999 and June 2002 to study the spatial distribution of diffuse CO2 degassing and estimate the total CO2 output from Showa-Shinzan volcanic dome, Japan. Seventy-six and 81 measurements of CO2 efflux were performed in 1999 and 2002, respectively, covering most of Showa-Shinzan volcano. Soil CO2 efflux data showed a wide range of values up to 552 g m-2 d-1. Carbon isotope signatures of the soil CO2 ranged from -0.9‰ to -30.9‰, suggesting a mixing between different carbon reservoirs. Most of the study area showed CO2 efflux background values during the 1999 and 2002 surveys (B = 8.2 and 4.4 g m-2 d-1, respectively). The spatial distribution of CO2 efflux anomalies for both surveys showed a good correlation with the soil temperature, indicating a similar origin for the
extensive soil degassing generated by condensation processes and fluids discharged by the fumarolic system of Showa-Shinzan.
The total diffuse CO2 output of Showa-Shinzan was estimated to be about 14.0–15.6 t d-1 of CO2 for an area of 0.53 km2. 相似文献