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51.
The behavior of lithium and its isotopes in oilfield brines: evidence from the Heletz-Kokhav field, Israel 总被引:2,自引:0,他引:2
Twenty-four brine samples from the Heletz-Kokhav oilfield, Israel, have been analyzed for chemical composition and Li isotope ratios. The chemical composition of the brines, together with geological evidence, suggests derivation from (Messinian) seawater by evaporation that proceeded well into the gypsum stability field but failed to reach the stage of halite crystallization. The present salinity of the samples (18-47 g Cl/L) was achieved by dilution of the original evaporitic brine by local fresh waters. Like brines from other sedimentary basins, the Li/Cl ratios in the Heletz-Kokhav samples show a prominent Li enrichment (five-fold to eight-fold) relative to modern seawater. The isotopic ratios of Li, expressed in the δ 6Li notation, vary from −26.3 to −17.9‰, all values being significantly higher than that of modern seawater (−32‰) irrespective of their corresponding Li concentration (1.0-2.3 mg/L). The isotopic composition of Li and the Li/Cl ratio in the oilfield brines were acquired in two stages: (a) The original evaporated seawater gained isotopically light Li during the diagenetic interaction between the interstitial Messinian brine and the basin sediments. A parent brine with an elevated Li/Cl ratio was formed. The brine was later diluted in the oilfields. (b) The δ 6Li values of the final brines were determined during epigenetic interaction with the Heletz-Kokhav aquifer rocks. At the same time, the Li/Cl ratio inherited from stage (a) remained largely unchanged. This work represents the first use of lithium isotopic composition to elucidate the origin and evolution of formation waters in sedimentary basins. 相似文献
52.
M. I. Wilkinson A. Vallenari C. Turon U. Munari D. Katz G. Bono M. Cropper A. Helmi N. Robichon F. Thévenin S. Vidrih T. Zwitter F. Arenou M.-O. Baylac G. Bertelli A. Bijaoui F. Boschi F. Castelli F. Crifo M. David A. Gomboc A. Gómez M. Haywood U. Jauregi P. de Laverny Y. Lebreton P. Marrese T. Marsh S. Mignot D. Morin S. Pasetto M. Perryman A. Pra A. Recio-Blanco F. Royer A. Sellier A. Siviero R. Sordo C. Soubiran L. Tomasella Y. Viala 《Monthly notices of the Royal Astronomical Society》2005,359(4):1306-1335
53.
54.
The present paper reviews and discusses the studies on heavy metals behavior in coastal sediments of southern California which have been published since 1970.The available data allow for the estimation of pollution-free ‘base-line’ concentrations of some heavy metals in southern California sediments (Ag, 0.4 ppm; Cd, 0.4 ppm; Cr, 25 ppm; Cu, 9 ppm; Ni, 15 ppm; Pb, 10 ppm; and Zn, 44 ppm) which may be used as references for monitoring future metal pollution.The transport of most, if not all, heavy metals through the near-shore and shelf environments is controlled by their association with particles, a significant fraction of which is sewage-derived and rich in organic carbon. Changes in the relative abundances of the heavy metals are brought about mainly by settling differentiation of their host particles, and much less so by diagenetic solubilization. The bulk of the heavy metals are transported, within fine-grained particles, out from the shelf into deep ocean regions.Simple linear mixing of polluted outfall materials with clean natural sediments cannot explain the distribution of heavy metals in near-shore and basinal sediments in southern California, unless significant protective effects of organic coatings (near outfalls) and of grain-size distributions are taken into account. Heavy metal pollution from oil seepages are significant for only a very limited number of metals (Ni, Ba, etc.) and only on a local scale.The urgent need for standardization of heavy metal leaching techniques is demonstrated and emphasized. 相似文献
55.
56.
Yunyan Ni Geoffrey S. Ellis Barry Katz Yongchun Tang 《Geochimica et cosmochimica acta》2011,75(10):2696-2707
Based on quantum chemistry calculations for normal octane homolytic cracking, a kinetic hydrogen isotope fractionation model for methane, ethane, and propane formation is proposed. The activation energy differences between D-substitute and non-substituted methane, ethane, and propane are 318.6, 281.7, and 280.2 cal/mol, respectively. In order to determine the effect of the entropy contribution for hydrogen isotopic substitution, a transition state for ethane bond rupture was determined based on density function theory (DFT) calculations. The kinetic isotope effect (KIE) associated with bond rupture in D and H substituted ethane results in a frequency factor ratio of 1.07. Based on the proposed mathematical model of hydrogen isotope fractionation, one can potentially quantify natural gas thermal maturity from measured hydrogen isotope values. Calculated gas maturity values determined by the proposed mathematical model using δD values in ethane from several basins in the world are in close agreement with similar predictions based on the δ13C composition of ethane. However, gas maturity values calculated from field data of methane and propane using both hydrogen and carbon kinetic isotopic models do not agree as closely. It is possible that δD values in methane may be affected by microbial mixing and that propane values might be more susceptible to hydrogen exchange with water or to analytical errors. Although the model used in this study is quite preliminary, the results demonstrate that kinetic isotope fractionation effects in hydrogen may be useful in quantitative models of natural gas generation, and that δD values in ethane might be more suitable for modeling than comparable values in methane and propane. 相似文献
57.
Rock fall hazard along the railway corridor to Jerusalem,Israel, in the Soreq and Refaim valleys 总被引:1,自引:1,他引:0
We evaluate rock fall hazard along the railway corridor to Jerusalem, Israel, in the Soreq and Refaim valleys. For the purpose,
we use a combination of historical information on past rock fall events, field surveys aided by the interpretation of aerial
photographs, and numerical rock fall modeling. Historical information indicates that on July 11, 1927 an m
L
6.2 Dead-Sea transform earthquake caused rock falls in the studied area. The seismically induced rock falls damaged the railway
tracks. Field observations revealed that the source area for the 1927 failures was located in the Aminadav formation, at the
contact with the Moza formation. At the stratigraphic contact, rock blocks 100–101 m3 in size are formed as a result of tensile stresses and associated fracturing in the dolomite of the Aminadav formation, combined
with continuous creep of the blocks on the marl of the underlying Moza formation. We use topographical, geological, and geomorphological
information to calibrate a three-dimensional numerical simulation of rock falls in the studied area. We use the results of
the numerical modeling, and additional independent information, to assess rock fall hazard and the associated risk in the
Soreq and Refaim valleys. Results indicate that in the studied area, rock fall risk to the railway line to Jerusalem is due
primarily to Dead-Sea transform earthquakes, with m
L
> 6. We identify nine sections of the railway line where rock fall risk exists, for a total length of 2.5 km. We further
note that seismically induced rock falls can produce damage to the road network in the studied area, make it difficult or
impossible for earthquake casualties to reach hospitals in Jerusalem. We conclude offering recommendations on how to mitigate
the risk posed by earthquake-induced rock falls in the studied area. 相似文献
58.
J. Kuparinen J. HallM. Ellwood K. SafiJ. Peloquin D. Katz 《Deep Sea Research Part II: Topical Studies in Oceanography》2011,58(6):800-807
We studied the microbial food web in the upper 100 m of the water column in iron-limited sub-Antarctic HNLC waters south-east of New Zealand in the SAGE experiment in 2004, with focus on bacterioplankton. Samples were collected daily from inside and outside the iron enriched patch. Short term enrichment experiments were conducted on board in 4 L polycarbonate bottles with water outside the iron enriched patch to study single and combined effects of micronutrient additions on microbial food web. Low bacterial growth was recorded in the study area with community turnover times of 50 h or more during the study period. Measurements of bacterial standing stocks and production rates in the study show minor responses to the large scale iron enrichment, with increase in rates and stocks after the first enrichment and at the end of the study period after the third iron enrichment when solar radiation increased and wind mixing decreased. The average daily bacterial production rates were 31.5 and 33.7 mgCm−2 d−1 for the OUT and IN stations, respectively; thus overall there was not a significant difference between the control and the iron-enriched patch. In the bottle experiments bacterial thymidine incorporation showed responses to single iron and silicic acid enrichments and a major growth response to the combined iron and sucrose enrichments. Phytoplankton chlorophyll-a showed clear stimulation by single additions of iron and silicic acid and silicic acid enhanced the iron impact. Cobalt additions had no effect on bacteria growth and a negative effect on phytoplankton growth. Low bacterial in situ growth rates and the enrichment experiments suggest that bacteria are co-limited by iron and carbon, and that bacterial iron uptake is dependent on carbon supply by the food web. With the high iron quota (??mol Fe mol C−1) bacteria may scavenge considerable amounts of the excess iron, and thus influence the relative importance of the microbial food web as a carbon sink. 相似文献
59.
J. I. Katz 《Astrophysics and Space Science》1992,189(1):163-168
It is argued that the hierarchical cosmological paradigm is a viable, and insufficiently appreciated, alternative to the Big Bang paradigm. Recent observational discoveries justify renewed interest in hierarchical models of the Universe. 相似文献
60.
Yossi Katz 《GeoJournal》1994,34(4):467-473
The idea of the Garden City, which was initiated by Ebenezer Howard at the end of the last century in England, was extended quickly to other places in the world. While the establishment of Garden Cities encountered many difficulties, there was much success in the establishment of Garden Suburbs. In Palestine, where Jewish immigrants and Zionist leaders brought Ebenezer Howard's ideas from Europe, Garden Suburbs were very successful. Zionism looked upon the Garden Suburb as the model for urban Zionist colonization in Palestine and it intended to establish such suburbs near all the big cities. Only Jews were supposed to live in those suburbs. The first Garden Suburb was Tel-Aviv near the port town of Jaffa. Subsequently, Tel-Aviv became the first Jewish city in Palestine. Following Tel-Aviv Jewish suburbs were established near Jerusalem, Haifa and Tiberias. In Palestine too, as in Europe, there were plans to establish Jewish Garden Cities, but they did not turn out well. 相似文献