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21.
An ocean circulation model for the British Columbia continental shelf is run with future initial conditions and forcing fields downscaled from the North American Regional Climate Change Assessment Program archive. Average seasonal sea surface temperatures for the period 2065 to 2078 are projected to increase by between 0.5° and 2.0°C with respect to analogous averages from 1995 to 2008. Seasonal sea surface salinities are projected to decrease by as much as 2.0 over the same period, though there are some regions where and periods when small increases are projected. Though stronger winter winds result in larger Haida Eddies, slightly stronger summer winds along the western Vancouver Island shelf do not result in appreciable changes to either the cross-shelf upwelling or to the magnitude of Juan de Fuca Eddies or the timing of their formation. However, increased flows are projected in some seasons for the Rose Spit, Middle Bank, and Goose Island Bank eddies. More precipitation over the watersheds emptying into coastal waters produces larger freshwater discharges and, in particular, a stronger estuarine flow in Juan de Fuca Strait and a stronger Vancouver Island Coastal Current. Generally increasing winds and decreasing density mean that the winter minus summer range of sea surface heights is projected to increase all along the coast. 相似文献
22.
Tidal inlets along the mesotidal coast of Maine contrast with those from other parts of the world by being dominated by flood-tidal
currents. Analysis of the factors responsible for flood or ebb dominance indicates factors external to the backbarrier environment.
We suggest that the flood dominance is caused by both a steepening of the tidal wave in the Gulf of Maine and the shallow
depth of the ebb-tidal delta and spit platform. Flood currents are typically 10–20 cm/sec stronger than the ebb at the inlet
throat. The flood dominance results in a significant net landward transport of sediment into the backbarrier. 相似文献
23.
The whale‐louse Scutocyamus antipodensis n.sp., ectoparasitic on Hector's dolphin, Cephalorhynchus hectori (van Beneden), is described and figured from material collected in Cloudy Bay, Cook Strait, New Zealand. Morphologically the new species is very close to S. parvus Lincoln & Hurley, the type and only other species of the genus, known only from the North Sea. However, the two species differ in the detailed structure and spinosity of the body and pereopods. 相似文献
24.
Henry C. Fricke Brady Z. Foreman Jacob O. Sewall 《Earth and Planetary Science Letters》2010,289(1-2):11-21
During the Late Cretaceous, western North America was characterized by a close geographic association between the Sevier highlands and the Western Interior Seaway. In this paper, an atmospheric general circulation model (AGCM) is used to simulate the impact of this geographic association on surface pressure, wind direction, and precipitation, and it is predicted that seasonal changes in these variables resulted in a strong monsoon along the eastern flank of the Sevier Highlands. Confirmation that these model simulations are accurate is provided by isotopic data from foreland basin sediments. In particular oxygen isotope records from different environments (large rivers, small streams and ponds) and proxies (unionid bivalve shells and paleosol carbonates) indicate that foreland basin streams were recharged by local precipitation with high oxygen isotope ratios while large trunk rivers were recharged by high-elevation precipitation. This hydrologic pattern is observed from Alberta to Utah and is consistent with east to west monsoonal air mass movements and associated seasonal rainfall. Recognition of a highland-driven monsoon has implication in regard to studies of fossil taphonomy, of water vapor transport, and of links between climate and mountain uplift and exhumation in this region. 相似文献
25.
Lincoln La Paz 《Meteoritics & planetary science》1944,3(10):137-141
The conclusion that tektite falls were restricted in time to an earlier era in Earth history is supported by all known facts, in particular, by the results of critical examinations of various reported falls, including 2 australite falls described not long ago by the late Dr. E. S. Simpson. On the contrary, if the tektites originate as “lunar impactites,” as Dr. H. H. Nininger has recently suggested, it seems evident that they would have continued to fall onto the Earth right up to the present time. Furthermore, the probability that the distribution of “lunar impactite” falls over the Earth's surface would exhibit the alinement along 3 great circles, which is characteristic of all known tektite deposits, is vanishingly small. 相似文献
26.
The significance of dilution in evaluating possible impacts of wastewater discharges from large cruise ships 总被引:1,自引:0,他引:1
Loehr LC Beegle-Krause CJ George K McGee CD Mearns AJ Atkinson MJ 《Marine pollution bulletin》2006,52(6):681-688
In response to public concerns about discharges from large cruise ships, Alaska's Department of Environmental Conservation (ADEC) sampled numerous effluents in the summer of 2000. The data showed that basic marine sanitation device (MSD) technology for black water (sewage) was not performing as expected. Untreated gray water had high levels of conventional pollutants and surprisingly high levels of bacteria. Both black water and gray water discharges sometimes exceeded state water quality standards for toxicants. The state convened a Science Advisory Panel (the Panel) to evaluate impacts associated with cruise ship wastewater discharges. The effluent data received wide media coverage and increased public concerns. Consequently, legislative decisions were made at the State and Federal level, and regulations were imposed before the Panel completed its evaluation. The Panel demonstrated that following the rapid dilution from moving cruise ships, the effluent data from the Summer of 2000 would not have exceeded water quality standards, and environmental effects were not expected. 相似文献
27.
Glenn J. MacPherson Christopher L. Andronicos Luca Bindi Vadim V. Distler Michael P. Eddy John M. Eiler Yunbin Guan Lincoln S. Hollister Alexander Kostin Valery Kryachko William M. Steinhardt Marina Yudovskaya Paul J. Steinhardt 《Meteoritics & planetary science》2013,48(8):1499-1514
A new meteorite find, named Khatyrka, was recovered from eastern Siberia as a result of a search for naturally occurring quasicrystals. The meteorite occurs as clastic grains within postglacial clay‐rich layers along the banks of a small stream in the Koryak Mountains, Chukotka Autonomous Okrug of far eastern Russia. Some of the grains are clearly chondritic and contain Type IA porphyritic olivine chondrules enclosed in matrices that have the characteristic platy olivine texture, matrix olivine composition, and mineralogy (olivine, pentlandite, nickel‐rich iron‐nickel metal, nepheline, and calcic pyroxene [diopside‐hedenbergite solid solution]) of oxidized‐subgroup CV3 chondrites. A few grains are fine‐grained spinel‐rich calcium‐aluminum‐rich inclusions with mineral oxygen isotopic compositions again typical of such objects in CV3 chondrites. The chondritic and CAI grains contain small fragments of metallic copper‐aluminum‐iron alloys that include the quasicrystalline phase icosahedrite. One grain is an achondritic intergrowth of Cu‐Al metal alloys and forsteritic olivine ± diopsidic pyroxene, both of which have meteoritic (CV3‐like) oxygen isotopic compositions. Finally, some grains consist almost entirely of metallic alloys of aluminum + copper ± iron. The Cu‐Al‐Fe metal alloys and the alloy‐bearing achondrite clast are interpreted to be an accretionary component of what otherwise is a fairly normal CV3 (oxidized) chondrite. This association of CV3 chondritic grains with metallic copper‐aluminum alloys makes Khatyrka a unique meteorite, perhaps best described as a complex CV3 (ox) breccia. 相似文献
28.
David Lincoln 《Area》2008,40(2):218-227
Offering the world's Least Developed Countries (LDCs) unhindered access to European markets for all exports other than arms, the European Union's Everything but Arms programme is the most favourable of its preferential trade arrangements. This paper discusses the classification of LDCs and focuses on the geography of LDC sugar trade to suggest unintended consequences of the EBA programme in creating new country configurations in the global South. 相似文献
29.
Jose A. Marengo Sin Chan Chou Gillian Kay Lincoln M. Alves José F. Pesquero Wagner R. Soares Daniel C. Santos André A. Lyra Gustavo Sueiro Richard Betts Diego J. Chagas Jorge L. Gomes Josiane F. Bustamante Priscila Tavares 《Climate Dynamics》2012,38(9-10):1829-1848
The objective of this study is to assess the climate projections over South America using the Eta-CPTEC regional model driven by four members of an ensemble of the Met Office Hadley Centre Global Coupled climate model HadCM3. The global model ensemble was run over the twenty-first century according to the SRES A1B emissions scenario, but with each member having a different climate sensitivity. The four members selected to drive the Eta-CPTEC model span the sensitivity range in the global model ensemble. The Eta-CPTEC model nested in these lateral boundary conditions was configured with a 40-km grid size and was run over 1961–1990 to represent baseline climate, and 2011–2100 to simulate possible future changes. Results presented here focus on austral summer and winter climate of 2011–2040, 2041–2070 and 2071–2100 periods, for South America and for three major river basins in Brazil. Projections of changes in upper and low-level circulation and the mean sea level pressure (SLP) fields simulate a pattern of weakening of the tropical circulation and strengthening of the subtropical circulation, marked by intensification at the surface of the Chaco Low and the subtropical highs. Strong warming (4–6°C) of continental South America increases the temperature gradient between continental South America and the South Atlantic. This leads to stronger SLP gradients between continent and oceans, and to changes in moisture transport and rainfall. Large rainfall reductions are simulated in Amazonia and Northeast Brazil (reaching up to 40%), and rainfall increases around the northern coast of Peru and Ecuador and in southeastern South America, reaching up to 30% in northern Argentina. All changes are more intense after 2040. The Precipitation–Evaporation (P–E) difference in the A1B downscaled scenario suggest water deficits and river runoff reductions in the eastern Amazon and S?o Francisco Basin, making these regions susceptible to drier conditions and droughts in the future. 相似文献
30.
The solvus in the system CO2-H2O-2.6 wt% NaCl-equivalent was determined by measuring temperature of homogenization in fluid inclusions which contained variable but the same amount of salt dissolved in the aqueous phase at room temperature. The critical point of the solvus is at 340 ± 5°C, at pressures between 1 and 2 kbar; this is about 65°C higher than for the pure CO2-H2O system. The solvus is assymetrical, with a steeper H2O-rich limb and with the critical point at mole fraction of water between 0.65 and 0.8. 相似文献