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91.
A. De Kemp 《Astrophysics and Space Science》1997,247(1-2):11-16
This contribution can only be a small collection of ideas and experiences from my (personal) publishing point of view. The
subject area assigned is very generic and there are indeed many developments going on, so I had to be very selective and restrictive,
while avoiding redundancies as much as I could. I have included some metaphors and paradigms, such as the shift from print
publications to electronic information. The traditional role of publishers in the information chain is compared with the new
opportunities that electronic publishing is offering now and may offer in the foreseeable future. From DTP to DTD, unplugged
and unbundled information, linearity, appropriateness, packaging and customizing, filters, intelligent agents, quality, integrity
and authenticity are some of the items hidden in the text. The overall conclusion is: the Internet still can learn a lot from
print...!
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
92.
Thomas?AngererEmail authorView authors OrcID profile Anthony?I.?S.?Kemp Steffen?G.?Hagemann Walter?K.?Witt Jo?o?O.?Santos Christian?Schindler Carlos?Villanes 《Contributions to Mineralogy and Petrology》2018,173(5):36
Mississippian arc magmatic suites of the Au-rich Pataz and Cu-dominated Montañitas regions in Peru reveal distinct modes of magmatic-hydrothermal petro- and metallogenesis. The distinction is remarkable due to their broad contemporaneity (336–322 Ma), arc-parallel position, and close distance (<?50 km) to each other. In both arc regions, petrography, geochemistry, and the tectonic setting of magmatic suites suggest a rapid switch from syn-collisional/compressional to post-collisional/extensional (with ‘A2-type’ signature) emplacement regime. Rocks of the Au-rich Pataz region originate from mixed sources with a contribution from the mantle (εHf?>?0 and δ18O of ~?5.3‰) and assimilated old crust (variously low εHf and δ18O >?5.3‰). The ultimate source of Au in the mineralised Pataz batholith was oxidised (fO2 at FMQ buffer; based on zircon trace chemistry) and alkali-, LILE- and HFSE-enriched, most likely represented by the metasomatised mantle. The syn-extensional emplacement of the relatively reduced (ΔFMQ?<?0), but unmineralised, A2-type suite involved assimilation of reduced crust. Associated, reduced, magmatic-hydrothermal fluids infiltrated the Au-bearing batholith suite and effectively mobilised and transported and concentrated Au. In the Montañitas region, rocks are oxidised (ΔFMQ?>?0) and dominantly mantle derived without significant incorporation of crustal material. Samples from the Cu-mineralised suites indicate the additional contribution of a δ18O <?5.3‰ source, potentially melted layer-2 gabbro. In addition, the elevated whole-rock La/Yb and Sr/Y ratios are compatible with minor addition of slab-derived material, which may have enhanced Cu endowment in this region. Late-magmatic, oxidised fluids derived from the younger A2-type suite controlled Cu mobilisation and concentration, while Au behaved largely refractory. In general terms, it is postulated that source mixing in continental arcs is a first-order control of contrasting Cu and Au endowment and that sequential intrusion processes facilitate late-magmatic-hydrothermal mobilisation and concentration of specific metal assemblages. 相似文献
93.
We evaluated two digital data sources that might be helpful in characterizing grasshopper habitat using plant and grasshopper species composition data collected at 128 sites in three areas of Montana. A GIS was used to associate each sampling site with Omernik's ecoregions and the Montana State Soil Geographic Database (MTSTATSGO). Detrended Correspondence Analysis (DCA) and statistical analyses were used to test for correlations among grasshopper species, available water capacity, and soil permeability across sampling areas and ecoregions. Four grasshopper species were correlated with soil permeability and six were correlated with available water capacity. MTSTATSGO plant cover percentages did not correlate with cover measured in the field, indicating inadequate resolution for the scale of this study. Ecoregions were useful in distinguishing grasshopper community gradients across Montana, from mountains to plains. These georeferenced data should be considered as input for grasshopper forecasting and decision-making models. Our results show how GIS can be used to evaluate relationships between digital data sets and ecological data gathered in the field. 相似文献
94.
95.
Charles B. Officer Daniel R. Lynch W.Michael Kemp Walter R. Boynton 《Estuarine, Coastal and Shelf Science》1985,21(3):357-364
Seasonal benthic respiration rate observations from Chesapeake Bay and the Patuxent estuary have been used to determine the benthic decay coefficient. Non-linear parameter estimation procedures were employed to delineate the optimal values and associated confidence intervals for the microbial decay and macrofaunal respiration parameters. The results demonstrate that microbial decay of organic detritus on the bottom is a long-term process with a yearly averaged decay coefficient of around k = 0·0056 day?1 (). 相似文献
96.
Robert Bolhar Uwe Ring Anthony I. S. Kemp Martin J. Whitehouse Steve D. Weaver Jon D. Woodhead I. Tonguc Uysal Rose Turnbull 《Contributions to Mineralogy and Petrology》2012,164(6):915-933
Zircons from 14 compositionally variable granitic rocks were examined in detail using CL image-guided micro-analysis to unravel the complex magmatic history above the southward retreating Hellenic subduction zone system in the Aegean Sea. Previously published U–Pb ages document an episodic crystallisation history from 17 to 11?Ma, with peraluminous (S-type) granitic rocks systematically older than closely associated metaluminous (I-type) granitic rocks. Zircon O- and Hf isotopic data, combined with trace element compositions, are highly variable within and between individual samples, indicative of open-system behaviour involving mantle-derived melts and evolved supracrustal sources. Pronounced compositional and thermal fluctuations highlight the role of magma mixing and mingling, in accord with field observations, and incremental emplacement of distinct melt batches coupled with variable degrees of crustal assimilation. In the course of partial fusion, more fertile supracrustal sources dominated in the earlier stages of Aegean Miocene magmatism, consistent with systematically older crystallisation ages of peraluminous granitic rocks. Differences between zircon saturation and crystallisation temperatures (deduced from zircon Ti concentrations), along with multimodal crystallisation age spectra for individual plutons, highlight the complex and highly variable physico-compositional and thermal evolution of silicic magma systems. The transfer of heat and juvenile melts from the mantle varied probably in response to episodic rollback of the subducting lithospheric slab, as suggested by punctuated crystallisation age spectra within and among individual granitic plutons. 相似文献
97.
98.
Justine Kemp Lynda C. Radke Jon Olley Steve Juggins Patrick De Deckker 《Quaternary Research》2012,77(1):65-76
Palaeosalinity records for groundwater-influenced lakes in the southwest Murray Basin were constructed from an ostracod-based, weighted-averaging transfer function, supplemented with evidence from Campylodiscus clypeus (diatom), charophyte oogonia, Coxiella striata (gastropod), Elphidium sp. (foraminifera), Daphniopsis sp. ephippia (Cladocera), and brine shrimp (Parartemia zietziana) faecal pellets, the δ18O of ostracods, and > 130 μm quartz sand counts. The chronology is based on optically stimulated luminescence and calibrated radiocarbon ages. Relatively wet conditions are marked by lower salinities between 9600 yr and 5700 yr ago, but mutually exclusive high- and low-salinity ostracod communities suggest substantial variability in effective precipitation in the early Holocene. A drier climate was firmly in place by 4500 yr and is marked at the groundwater-dominated NW Jacka Lake by an increase in aeolian quartz and, at Jacka Lake, by a switch from surface-water to groundwater dominance. Short-lived, low-salinity events at 8800, 7200, 5900, 4800, 2400, 1300 and 400 yr are similar in timing and number to those recorded on Australia's southern continental shelf, and globally, and provide evidence for the existence of the ~ 1500-yr cycle in mainland southern Australia. We surmise that these are cool events associated with periodic equatorward shifts in the westerly wind circulation. 相似文献
99.
Dan J. Lapworth Katherine V. Knights Roger M. Key Christopher C. Johnson Emmanuel Ayoade Michael A. Adekanmi Tunde M. Arisekola Olugbenga A. Okunlola Birgitta Backman Mikael Eklund Paul A. Everett Robert T. Lister John Ridgway Michael J. Watts Simon J. Kemp Peter E.J. Pitfield 《Applied Geochemistry》2012
This paper provides an overview of regional geochemical mapping using stream sediments from central and south-western Nigeria. A total of 1569 stream sediment samples were collected and 54 major and trace elements determined by ICP-MS and Au, Pd and Pt by fire assay. Multivariate statistical techniques (e.g., correlation analysis and principal factor analysis) were used to explore the data, following appropriate data transformation, to understand the data structure, investigate underlying processes controlling spatial geochemical variability and identify element associations. Major geochemical variations are controlled by source geology and provenance, as well as chemical weathering and winnowing processes, more subtle variations are a result of land use and contamination from anthropogenic activity. 相似文献
100.
John Kemp 《Journal of African Earth Sciences》1996,22(4):507-523
The Kuara Formation was originally described in the Nuqrah quadrangle, northern Arabian Shield, as composed of sedimentary and volcanic rocks and attributed to the Neoproterozoic Shammar group. The group has been examined in the type area of the Kuara Formation. The name ‘Kuara Formation’ is here formally proposed and restricted to the essentially sedimentary succession. The sediments were most likely deposited in an approximately north-south to northeast-southwest fault-bounded basin more than 20 km wide and closed to the south by an approximately east-west fault. The formation probably attained more than 600 m in thickness and is characterized by abundant, locally derived conglomerate and by coarsening-upward sequences organized in megasequences; these are interpreted as representing the progradation of alluvial fans into a lake. Sharp contacts of siltstone overlying conglomerate are interpreted as due to the lowering of the trough floor by faulting, subsequent lacustrine sedimentation corresponding to periods of maximum tectonic activity and alluvial fans prograding, periods of reduced activity. The interpretation of the tectonic environment as one of extensional faulting in a continental setting is in agreement with interpretations proposed for other successions of similar age in Arabia and Egypt. 相似文献