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121.
Yus Budiyono Jeroen Aerts JanJaap Brinkman Muh Aris Marfai Philip Ward 《Natural Hazards》2015,75(1):389-413
122.
Haid Maren Gohm Alexander Umek Lukas Ward Helen C. Rotach Mathias W. 《Boundary-Layer Meteorology》2022,182(3):335-362
Boundary-Layer Meteorology - We present a comprehensive analysis of four south föhn events observed during the Penetration and Interruption of Alpine Foehn (PIANO) field campaign in the Inn... 相似文献
123.
Roy C. Ward 《水文科学杂志》2013,58(6):635-636
Abstract In order to estimate areal evapotranspiration (ET), a system using Landsat MSS and elevation data is developed. After extraction of the study area and its geometric correction, Landsat MSS data are classified into land use categories, which give empirical parameters for calculation of ET. Elevation data, which are originally given at the mesh of 7.5” in latitude by 11.25” in longitude, are interpolated and fitted to each pixel of land use image data. Calculation of ET is executed by using empirical functions in terms of meteorological elements which are linearly regressed with elevation from data at several observatories. The calculated results are represented by the form of not only statistical quantities but also transformed image data. The distribution of ET over mountainous areas, represented as image data, reasonably shows the effect of topography. After comparing with observed data of pan evaporation and with the values estimated by Thornthwaite's method, one can conclude that this system would reliably estimate the actual monthly ET over large areas. 相似文献
124.
Sixteen elements (Ca, K, Mg, Na, Al, Fe, Mn, P, Co, Cu, Li, Ni, Rb, Sr, Ti, Zn, determined by atomic absorption) were identified in 453 pumice fragments recovered from Holocene strandplains in southeast Queensland and New South Wales. Eight pumice groups and 13 subgroups are recognised by numerical analysis. Some pumices record known eruptions. Others come from known centres in Tonga and Vanuatu. Several pumice eruptions have occurred from some centres, but there are instances of single episodes. The numerical analyses, combined with carbon dating and soil identification, identify marker horizons in the development of the strandplains. These horizons provide a time‐scale for soil development. Pumice that occurs in middens has an archaeological value. Coke was found with recent pumice. It conveniently identifies the modern industrial age. 相似文献
125.
At Brisbane Airport, the construction of a diversion channel for Kedron Brook exposed a former beach, low cliff and sand spit, which, with their associated sediments and acid sulfate soils, demonstrate a postglacial high sea-level 1.3 – 1.4 m above present mean sea-level. The beach appears to date from 4000 to 5000 y BP. It varies in level where it lies above soft ground; these variations, and sag depressions that follow buried streamlines, indicate sediment consolidation since withdrawal of the sea from the former shore. Most of the area consists of former estuarine deposits, mangrove and saline marshes, and stranded tidal flats on which acid sulfate soils are widely developed. The modern landforms mostly reproduce subsurface features, to the extent that the surface relief replicates the landscape transgressed by the sea 7000 years ago. A small rise of sea-level possibly to +0.65 m occurred about 2000 – 3000 years ago. Foredunes near the present shore that are related to a slightly lower level 1000 – 500 years ago (?0.25 m) are currently subject to wave erosion. 相似文献
126.
Vulnerability indicators of sea water intrusion 总被引:5,自引:0,他引:5
In this paper, simple indicators of the propensity for sea water intrusion (SWI) to occur (referred to as "SWI vulnerability indicators") are devised. The analysis is based on an existing analytical solution for the steady-state position of a sharp fresh water-salt water interface. Interface characteristics, that is, the wedge toe location and sea water volume, are used in quantifying SWI in both confined and unconfined aquifers. Rates-of-change (partial derivatives of the analytical solution) in the wedge toe or sea water volume are used to quantify the aquifer vulnerability to various stress situations, including (1) sea-level rise; (2) change in recharge (e.g., due to climate change); and (3) change in seaward discharge. A selection of coastal aquifer cases is used to apply the SWI vulnerability indicators, and the proposed methodology produces interpretations of SWI vulnerability that are broadly consistent with more comprehensive investigations. Several inferences regarding SWI vulnerability arise from the analysis, including: (1) sea-level rise impacts are more extensive in aquifers with head-controlled rather than flux-controlled inland boundaries, whereas the opposite is true for recharge change impacts; (2) sea-level rise does not induce SWI in constant-discharge confined aquifers; (3) SWI vulnerability varies depending on the causal factor, and therefore vulnerability composites are needed that differentiate vulnerability to such threats as sea-level rise, climate change, and changes in seaward groundwater discharge. We contend that the approach is an improvement over existing methods for characterizing SWI vulnerability, because the method has theoretical underpinnings and yet calculations are simple, although the coastal aquifer conceptualization is highly idealized. 相似文献
127.
128.
Typical of glaciated environments, the inner continental shelf of New Hampshire is composed of bedrock outcrops, remnants of glacial deposits (for example, drumlins), sand and gravel deposits, as well as muddier sediments farther offshore. A number of previous studies have defined the general trends of the New Hampshire inner shelf from the coarser deposits nearer the shore to the muddier outer basins. Most recently, a seismic survey (150 km of side-scan sonar and subbottom seismic profiles), as well as bottom sediment sampling (74 stations), has provided a detailed bottom map of the southern New Hampshire shelf area (landward of the 30-m contour). The surficial sediments within this area range from very fine sand to gravel. Bedrock outcrops are common. The seismic survey indicated several large sand deposits exceeding 6-8 m in thickness that occur relatively close to the coast. These sedimentary units, which are within 3 km of the shoreline, are composed of fine to medium sands. Examination of the general morphology and depositional setting indicates at least some of these features are probably relic ebb tidal delta shoals. However, a large eroding drumlin occurs between two of the sand bodies and may represent the source of these deposits. Additional work is needed to verify the origin of these sediment bodies. 相似文献
129.
Makoto Naoi Masao Nakatani Shigeki Horiuchi Yasuo Yabe Joachim Philipp Thabang Kgarume Gilbert Morema Sifiso Khambule Thabang Masakale Luiz Ribeiro Koji Miyakawa Atsushi Watanabe Kenshiro Otsuki Hirokazu Moriya Osamu Murakami Hironori Kawakata Nana Yoshimitsu Anthony Ward Ray Durrheim Hiroshi Ogasawara 《Pure and Applied Geophysics》2014,171(10):2665-2684
We investigated frequency-magnitude distribution (FMD) of acoustic emissions (AE) occurring near an active mining front in a South African gold mine, using a catalog developed from an AE network, which is capable of detecting AEs down to M W ?5. When records of blasts were removed, FMDs of AEs obeyed a Gutenberg?Richter law with similar b values, not depending on post-blasting time from the initial 1-min interval through more than 30 h. This result denies a suggestion in a previous study (Richardson and Jordan Bull Seismol Soc Am, 92:1766–1782, 2002) that new fractures generated by blasting disturb the size distribution of background events, which they interpreted as slip events on existing weak planes. Our AE catalog showed that the GR law with b ~ 1.2 was valid between M W ?3.7 and 0 for AEs around the mining front. Further, using the mine’s seismic catalog, which covers a longer time period of the same area, we could extend the validity range of the GR law with the same b value up to M W 1. 相似文献
130.