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881.
This paper presents an analysis of a neglected area of study by geographers; that of resident action groups. During the 1980s there has been a significant increase in the number of resident action groups throughout Sydney. Resident activism has influenced local planning processes, the location of noxious facilities and subsequent urban form. This has initiated important reactions by government at both the local and State levels. Urban collective activisms have been hypothesised as single‐issue, self‐serving nimby groups. However, RAGs are also empowering forces, in which women and men are introduced to the political structures and become engaged in protest and resistance that can challenge the social and spatial order. RAGs can, either singularly or cumulatively, force a re‐aligning of existing power relations, and they can necessitate changed modes of governance (or govern‐mentality). 相似文献
882.
An index was developed for estuarine macrobenthos in the Gulf of Mexico that discriminated between areas with degraded environmental conditions and areas with undegraded or reference conditions. Test sites were identified as degraded or reference based on criteria for dissolved oxygen levels, sediment toxicity tests, and sediment contamination. Discriminant analysis was used to identify a suite of measures of benthic community composition and diversity that would most successfully distinguish degraded from undegraded sites. The resultant benthic index was composed of a linear combination of three factors: the Shannon-Wiener diversity index, the proportion of total benthic abundance as tubificid oligochaetes, and the proportion of total benthic abundance as bivalve molluscs. This index was used to evaluate the spatial patterns of degraded benthic resources in the Gulf of Mexico. 相似文献
883.
Luther III George W. Karolewski Jennifer S. Sutherland Kevin M. Hansel Colleen M. Wankel Scott D. 《Aquatic Geochemistry》2021,27(3):207-220
Aquatic Geochemistry - Given their environmental abundances, it has been long hypothesized that geochemical interactions between reactive forms of manganese and nitrogen may play important roles in... 相似文献
884.
Jason B. Burt Nancy L. Ross G. V. Gibbs George R. Rossman Kevin M. Rosso 《Physics and Chemistry of Minerals》2007,34(5):295-306
Potential protonation sites for, kyanite, sillimanite, and andalusite, located in a mapping of the (3, −3) critical points
displayed by their L(r) = −∇2ρ(r) distributions, are compared with polarized single-crystal FTIR spectra of kyanite and sillimanite determined earlier and
with andalusite measured in this study. For andalusite, seven peaks were observed when the electric vector, E, is parallel to [100]: four intense ones at 3,440, 3,460, 3,526, and 3,597 cm−1 and three weaker ones at 3,480, 3,520, and 3,653 cm−1. Six peaks, three intense ones at 3,440, 3,460, and 3,526 cm−1 and three weaker ones at 3,480, 3,520, and 3,653 cm−1 when E parallels [010]. No peaks were observed when E is parallel to [001]. The concentration of water in andalusite varies between 110 and 168 ppm by weight % H2O. Polarized FTIR spectra indicate that the OH vector is parallel to (001) in andalusite and sillimanite and
in kyanite. Examination of the L(r) (3, −3) critical points in comparison with the polarized FTIR indicates that H prefers to bond to the oxygen atoms O1 and
O2 in andalusite and O2 and O4 in sillimanite which correspond to the underbonded oxygen atoms and those with the largest
L(r) maxima. In kyanite, comparison of the FTIR spectrum and the critical points indicates that H will preferentially bond to
the two 4-coordinated O2 and O6 atoms. 相似文献
885.
Kevin D. Ash 《GeoJournal》2017,82(3):533-552
Occupants of mobile or manufactured homes in the United States of America (USA) are highly exposed and susceptible to injury or death from tornado hazards. This problem is most pronounced in the southern and eastern USA, where tornadoes are frequent and mobile homes comprise upwards of 15 % of the housing stock. Recognizing this vulnerability, emergency management entities and the USA National Weather Service often recommend that mobile home residents evacuate to a nearby sturdy building or a specially-built tornado shelter when tornadoes threaten their communities. Previous research suggests, however, that only 30 % of residents follow this recommendation. In this research I aim to provide insight as to why many mobile home residents seldom undertake the suggested course of action for tornadoes. Using excerpts from twenty semi-structured interviews conducted during 2013 in South Carolina, I show that some individuals understand physical characteristics of tornadoes very differently than experts do. In addition, mobile home residents may also hold views that differ from experts about the ability of their homes to withstand tornadic winds and debris. Even if mobile home occupants pay close attention to thunderstorm hazards and might be willing to evacuate, they may prioritize protective actions for lightning or flash flooding over those recommended for tornadoes. Finally, the interviews reveal that there is much confusion over where to go, when to leave, and which route to take to arrive safely at a sheltering place for tornado hazards. I discuss some of the potential ramifications of the findings for theory and practice and suggest how future research might build on this work. 相似文献
886.
Hydrological processes and conditions were quantified for the Mersey River Basin (two basins: one exiting below Mill Falls, and one exiting below George Lake), the Roger's Brook Basin, Moosepit Brook, and for other selected locations at and near Kejimkujik National Park in Nova Scotia, Canada, from 1967 to 1990. Addressed variables included precipitation (rain, snow, fog), air temperature, stream discharge, snowpack accumulations, throughfall, soil and subsoil moisture, soil temperature and soil frost, at a monthly resolution. It was found that monthly per hectare stream discharge was essentially independent of catchment area from <20 km2 to more than 1000 km2. The forest hydrology model ForHyM2 was used to simulate monthly rates of stream discharge, throughfall and snowpack water equivalents for mature forest conditions. These simulations were in good agreement with the historical records once the contributions of fog and mist to the area‐wide water budget were taken into account, each on a monthly basis. The resulting simulations establish a hydrologically consistent, continuous, comprehensive and partially verified record for basin‐wide outcomes for all major hydrological processes and conditions, be these related to stream discharge, soil moisture, soil temperature, snowpack accumulations, soil frost, throughfall, interception and soil percolation. Copyright © 2000 John Wiley & Sons, Ltd. 相似文献
887.
Changes in the Probability of Heavy Precipitation: Important Indicators of Climatic Change 总被引:40,自引:0,他引:40
Pavel Ya. Groisman Thomas R. Karl David R. Easterling Richard W. Knight Paul F. Jamason Kevin J. Hennessy Ramasamy Suppiah Cher M. Page Joanna Wibig Krzysztof Fortuniak Vyacheslav N. Razuvaev Arthur Douglas Eirik Førland Pan-Mao Zhai 《Climatic change》1999,42(1):243-283
A simple statistical model of daily precipitation based on the gamma distribution is applied to summer (JJA in Northern Hemisphere, DJF in Southern Hemisphere) data from eight countries: Canada, the United States, Mexico, the former Soviet Union, China, Australia, Norway, and Poland. These constitute more than 40% of the global land mass, and more than 80% of the extratropical land area. It is shown that the shape parameter of this distribution remains relatively stable, while the scale parameter is most variable spatially and temporally. This implies that the changes in mean monthly precipitation totals tend to have the most influence on the heavy precipitation rates in these countries. Observations show that in each country under consideration (except China), mean summer precipitation has increased by at least 5% in the past century. In the USA, Norway, and Australia the frequency of summer precipitation events has also increased, but there is little evidence of such increases in any of the countries considered during the past fifty years. A scenario is considered, whereby mean summer precipitation increases by 5% with no change in the number of days with precipitation or the shape parameter. When applied in the statistical model, the probability of daily precipitation exceeding 25.4 mm (1 inch) in northern countries (Canada, Norway, Russia, and Poland) or 50.8 mm (2 inches) in mid-latitude countries (the USA, Mexico, China, and Australia) increases by about 20% (nearly four times the increase in mean). The contribution of heavy rains (above these thresholds) to the total 5% increase of precipitation is disproportionally high (up to 50%), while heavy rain usually constitutes a significantly smaller fraction of the precipitation events and totals in extratropical regions (but up to 40% in the tropics, e.g., in southern Mexico). Scenarios with moderate changes in the number of days with precipitation coupled with changes in the scale parameter were also investigated and found to produce smaller increases in heavy rainfall but still support the above conclusions. These scenarios give changes in heavy rainfall which are comparable to those observed and are consistent with the greenhouse-gas-induced increases in heavy precipitation simulated by some climate models for the next century. In regions with adequate data coverage such as the eastern two-thirds of contiguous United States, Norway, eastern Australia, and the European part of the former USSR, the statistical model helps to explain the disproportionate high changes in heavy precipitation which have been observed. 相似文献
888.
889.
Kevin Crean 《The Australian geographer》2000,31(3):367-382
The paper compares and contrasts the development experiences of two fisheries-dependent archipelagos: the Shetland Islands, located in the temperate seas of the North-east Atlantic, and the Lau community of the island of Malaita, in the Solomon Islands of the tropical Pacific Ocean. Whilst the coastal communities of both island groups have always depended upon the sea for their livelihood, their indigenous peoples are distinct in origins, culture, historic tradition, economy, and social imperatives. However, a closer examination of the recent development of the two archipelagos reveals that, whilst they are contrasting in the fisheries sector specifics, they have, over different time scales, adopted similar management strategies in the pursuit of sustainable fishing. In both instances, the island communities have sought to support the local fisheries economy by tempering the external forces of the centre. This has been achieved, with varying degrees of success, by adopting management control and resource 'ownership' strategies in response to social and economic turbulence in the environment. The experiences of the two archipelagos have demonstrated that to maintain a coherent fisheries management strategy over time and a sustainable resources base requires a pro-active approach, the input of resources, and moderation of the pressures created by the market. The future is uncertain as the fisheries organisations of the archipelagos seek to stabilise the access and ownership arrangements applied to the common-property fisheries resources of coastal waters. 相似文献
890.