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91.
92.
The study area is situated in a large agricultural field which produces tobacco, maize, and other yearly cultivated vegetables in Tekkeköy, Samsun (NE-Turkey). In addition, a significant part of this area to the north along the Black Sea coast is occupied by several industrial plants such as a copper smelting plant (KB?), a fertilizer plant (Tügsa?) and industrial park facilities (IPF). In order to reveal their environmental impacts, heavy metal analyses were conducted on soil, plant leaves and water samples collected within an area of approximately 30 km2 around these plants. Soil samples within an area of 10 km2 around these facilities are found to be highly polluted with Cu, Zn, Pb, Fe and Mn. Pollution occurs at surface and sharply dies out at 20 cm downwards in soil profile. Since the region is polluted mostly with base metals, the copper smelting factory appears to be the main source of pollution as it processes the massive sulfidic ores of the Black Sea area. Plants show Cu, Pb, Zn and Fe pollution around KB? and Tügsa? and Cu and Pb around IPF. Pollutants observed in tobacco (Nicotiana tobacum) are Cu, Pb, Zn, Fe and S; in maize (Zea mays) Cu, Zn and Fe; and in cabbage (Brassica oleracea) Cu, Pb, Fe and S. The analyses of water samples collected from the study area reveal that Pb and, to a lesser degree, Cu and Fe pollution stem from KB?; Cu, Fe and Mn pollution from Tügsa?; Pb and minor amounts of Fe and Mn pollution from IPF. Factor analyses from analyzed metals and anionic complexes in water show three distinct groups: (a) an association of heavy metals with Na, K and Mg referring to pollution and acid leaching of soil, (b) an association of NH4, Fe, SO4, Cl and Br indicating agricultural pollution and sea-water invasion in land near the shore line, and (c) HCO3 behaving in a different manner in heavy metal precipitation. 相似文献
93.
Temür Rasim Damcı Erdem Öncü-Davas Seda Öser Cihan Sarğın Sinan Şekerci Çağla 《Natural Hazards》2021,106(1):401-434
Natural Hazards - The earthquake in Sivrice, the district of Elaz??, took place at 20:55 (with local time, GMT+3) on January 24, 2020, with a magnitude of 6.8 in Turkey. This earthquake... 相似文献
94.
Natural Hazards - Slope stability is one of the most important issues of geotechnical engineering. Significant slope failures (landslides), which result from earthquakes, can cause considerable... 相似文献
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96.
In this work, some solutions of magnetohydrodynamic (MHD) equations are searched in order to investigate some large scale physical quantities in the sunspot dominated latitudinal regions near the equatorial plane. Special separation of variables is used to obtain the radial and latitudinal changes in spherical coordinates. Present parametric analysis yields three important parameters which are the sphericity, density and radial components shape parameters in the latitudinal distributions of physical variables. In the region of interest there is a considerable change in physical quantities with respect to regions where sunspots do not appear. 相似文献
97.
Aftershock sequences of the magnitude M W =6.4 Bingöl earthquake of 1 May, 2003 (Turkey) are studied to analyze the spatial and temporal variability of seismicity parameters of the b value of the frequency-magnitude distribution and the p value describing the temporal decay rate of aftershocks. The catalog taken from the KOERI contains 516 events and one month’s time interval. The b value is found as 1.49 ± 0.07 with Mc =3.2. Considering the error limits, b value is very close to the maximum b value stated in the literature. This larger value may be caused by the paucity of the larger aftershocks with magnitude M D ≥ 5.0. Also, the aftershock area is divided into four parts in order to detect the differences in b value and the changes illustrate the heterogeneity of the aftershock region. The p value is calculated as 0.86 ± 0.11, relatively small. This small p value may be a result of the slow decay rate of the aftershock activity and the small number of aftershocks. For the fitting of a suitable model and estimation of correct values of decay parameters, the sequence is also modeled as a background seismicty rate model. Constant background activity does not appear to be important during the first month of the Bingöl aftershock sequences and this result is coherent with an average estimation of pre-existing seismicity. The results show that usage of simple modified Omori law is reasonable for the analysis. The spatial variability in b value is between 1.2 and 1.8 and p value varies from 0.6 to 1.2. Although the physical interpretation of the spatial variability of these seismicity parameters is not straightforward, the variation of b and p values can be related to the stress and slip distribution after the mainshock, respectively. The lower b values are observed in the high stress regions and to a certain extent, the largest b values are related to Holocene alluvium. The larger p values are found in some part of the aftershock area although no slip occurred after the main shock and it is interpreted that this situation may be caused by the alluvium structure of the region. These results indicate that the spatial distribution in b and p values are generally related to the rupture mechanism and material properties of an aftershock area. 相似文献
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99.
Burcu Togral Koca 《Geographical review》2019,109(4):544-561
Using the case of Berlin, this article examines civil society actors in relation to local bordering practices following the large number of refugee arrivals in 2015. Combining critical border, migration, and urban studies and adopting a Foucauldian lens, the article aims to illustrate to what extent civil society actors have challenged and transformed local bordering practices vis‐à‐vis refugees within a specific urban space. The analysis illustrates that civil society actors have created new spaces of inclusion for refugees and brought new political and normative challenges to the established notions of belonging. On the other hand, they have also reproduced bordering practices either by their integration into formal state structures or by reinforcing hierarchical categorizations and unequal power relations embedded in the notion of humanitarianism. Finally, the article argues that these de/re‐bordering practices of civil society actors should be understood in line with the constraints that established bordering processes and the existing political and structural dynamics placed on them. 相似文献
100.
The second part of the First Byurakan Survey is aimed at detecting all bright (B < 16.5) UV-excess starlike objects in a large
area of the sky. By comparison with other major surveys such as the ROSA T All Sky Survey, the ROSAT WGACAT catalogue of point
sources, the IRAS survey, the 6cm Green Bank, the 1.4GHz NRAO VLA, and the 92cm Westerbork Northern sky surveys and with the
catalogue of mean UBVdata on stars, we estimate the number of AGNs present in the FBS survey and its completeness. We have made spectroscopic observations
of nine of the most promising FBS candidates. We have found six new QSOs, bringing the total number of known QSOs in this
survey to 42. By comparison with the Bright Quasar Survey, we found that the completeness of this last survey is of the order
of 70% rather than 30–50% as suggested by several authors.
Based party on observations collected at the Observatorie de Haute-Provence (CNRS, France). The APS databases are supported
by the National Foundation, the National Aeronautics and Space Administration, and the University of Minnesota, and are available
at hup:// aps.umn.edu. The Digitized Sky Survey was produced at the Space Telescope Science Institute (STScI) under U.S. Government
Grant NAG W-2166.
Published in Astrofizika, Vol. 42, No. 1, pp. 5–22, January–March, 1999. 相似文献