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231.
232.
Due to limited resources, publicly funded service programs need to operate efficiently. This paper demonstrates how a Spatial Decision Support System (SDSS) can be used to evaluate and enhance the performance of an existing service delivery program. Elements critical to the efficiency of service programs are enumerated. A meals-on-wheels (MOW) program in Connecticut is used as a case study to demonstrate the utility of the SDSS approach. Practical issues related to data sources and system adoption are discussed. 相似文献
233.
Judith Carney 《Geographical review》2017,107(3):433-451
Mangroves emerged a crucial habitat for Africans and their descendants during the transatlantic slave trade. Europeans avoided mangroves because of the deadly fevers that frequently claimed the lives of those who ventured there. Many were felled by lethal falciparum malaria, against which Africans alone carried genetic resistance. The transatlantic slave trade spread the disease‐causing plasmodium to New World Anopheles mosquitoes through infected bloodstreams, extending African mangroves’ pestilential reputation to the Neotropics. On both sides of the Atlantic, an environment Europeans feared provided Africans food, basic necessities, and sometimes, refuge from slavery. In Neotropical mangroves Africans largely replaced declining Amerindian populations, who were also immunologically vulnerable to the introduced plasmodium. Today, African descendants in Old and New World mangroves demonstrate longstanding human use of this ecosystem. Comparison of shellfish gathering and gendered collection patterns in mangroves recognizes Amerindian and African influences in Neotropical mangroves and illuminates the connections to transatlantic diasporic history. The discussion considers how a more‐than‐human geography shaped “place‐based knowledge” of mangrove swamplands that remained marginal to European territorializing during the colonial period. African and Afro‐descendant place‐making underscores the ways people, plants, insects, microbes, shellfish, and tides framed geography and diasporic identity at the periphery of the Atlantic world. 相似文献
234.
Horsburgh Kevin Haigh Ivan D. Williams Jane De Dominicis Michela Wolf Judith Inayatillah Addina Byrne David 《Ocean Dynamics》2021,71(6-7):715-730
Ocean Dynamics - In this paper, we show that over the next few decades, the natural variability of mid-latitude storm systems is likely to be a more important driver of coastal extreme sea levels... 相似文献
235.
Bosschaart Adwin Kuiper Wilmad van der Schee Joop Schoonenboom Judith 《Natural Hazards》2013,69(3):1661-1680
Natural Hazards - Until now, flood-risk perception in the Netherlands has been solely studied as it relates to adults. This exploratory study focused on 15-year-old students who have taken... 相似文献
236.
Serena Coetzee Judith Bishop 《International journal of geographical information science》2013,27(9):1179-1209
The original purpose of addresses was to enable the correct and unambiguous delivery of postal mail. The advent of computers and more specifically geographic information systems (GIS) opened up a whole new range of possibilities for the use of addresses, such as routing and vehicle navigation, spatial demographic analysis, geo‐marketing, and service placement and delivery. Such functionality requires a database which can store and access spatial data effectively. In this paper we present address databases and justify the need for national address databases. We describe models used for national address databases, and present our evaluation framework for an address database at a national level within the context of a spatial data infrastructure (SDI). The models of data harvesting, federated databases and data grids are analyzed and evaluated according to our novel framework, and we show that the data grid model has some unique features that make it attractive for a national address database in an environment where centralized control and/or coordination is difficult or undesirable. 相似文献
237.
Inequalities are no respecter of countries, including the affluent ones. Nevertheless, these problems appear to prevail more in the developing countries, which have the dubious distinction of having the highest degrees of inequalities in the world. Inequalities exist between urban and rural areas, as well as between the various regions. This paper discusses inequalities in Ghana and Zimbabwe, emphasizing the rural–urban dichotomy. Using data from the Ghana Demographic and Health Surveys (GDHS) and the Zimbabwe Demographic and Health Surveys (ZDHS) conducted by the respective statistical authorities of both countries and Macro International, the paper analyses existing inequalities in both countries. The paper also attempts to elucidate and understand the causes. It concludes that the traditional explanation of disparities that attribute the conditions to aberrations in the operations of market forces, while having some validity, may not provide a full explanation for Ghana and Zimbabwe’s predicament. It argues that whilst the existing disparities may be rooted in history, their persistence and worsening in the post-independence era could only be understood with reference to the corruption, nepotism and the mismanagement that have characterized these states since they gained their independence. 相似文献
238.
The origin of chromitites and related PGE mineralization in the Bushveld Complex: new mineralogical and petrological constraints 总被引:2,自引:0,他引:2
Naldrett A. J. Wilson Allan Kinnaird Judith Yudovskaya Marina Chunnett Gordon 《Mineralium Deposita》2012,47(3):209-232
This article reports a study of chromitites from the LG-1 to the UG-2/3 from the Bushveld Complex. Chromite from massive chromitite
follows two compositional trends on the basis of cation ratios: trend A—decreasing Mg/(Mg + Fe) with increasing Cr/(Cr + Al);
trend B—decreasing Mg/(Mg + Fe) with decreasing Cr/(Cr + Al). The chromitites are divided into five stages on the basis of
which trend they follow and the data of Eales et al. (Chemical Geology 88:261–278, 1990) on the behaviour of the Mg/Fe ratio of the pyroxene and whole rock Sr isotope composition of the environment in which they
occur. Following Eales et al. (Chemical Geology 88:261–278, 1990), the different characteristics of the stages are attributed to the rate at which new magma entered the chamber and the effect
of this on aAl2O3 and, in the case of stage 5, the appearance of cumulus plagioclase buffering the aAl2O3. The similarity of PGE profiles across the MG-3 and MG-4 chromitites that are separated laterally by up to 300 km and the
variation in V in the UG-2 argue that the chromitites have largely developed in situ. Modelling using the programme MELTS
shows that increase in pressure, mixing of primitive and fractionated magma, felsic contamination of primitive magma or addition
of H2O do not promote crystallization of spinel before orthopyroxene (in general they hinder it) and that the Cr2O3 content of the magma was of the order of 0.25 wt.%. Less than 20% of the chromite in the magma is removed before orthopyroxene
joins chromite, which implies a >13-km thickness of magma for the Critical Zone. It is suggested that the large excess of
magma has escaped up marginal structures such as the Platreef. The PGE profile of chromitites depends on whether sulphide
accumulated or not along with chromite. Modelling shows that contamination of Critical Zone magma with a felsic melt will
induce sulphide immiscibility, although not chromite precipitation. The LG-1 to LG-4 chromitites developed without sulphide,
whilst those from the LG-5 upwards had associated liquid sulphide. Much of the sulphide originally in the LG-5 and above has
been destroyed as a result of reaction with the chromite. 相似文献
239.
The δC13 and δO18 values of skeletons of shallow water, ahermatypic scleractinian corals from Jamaica show an excellent correlation over a wide range of isotopic composition. Within individual specimens there are large differences in the isotopic composition of separate skeletal elements. Some of these ahermatypes are enriched in O18 relative to equilibrium precipitates of calcium carbonate from Jamaican sea water. Therefore our data do not support a two-reservoir mixing model for calcification if one of these reservoirs consists of dissolved marine (inorganic) bicarbonate. As some of these ahermatypic species are enriched in both C13 and O18 relative to hermatypic corals from the same reefs, calcification models based on withdrawal of metabolic CO2 by photosynthesizing zooxanthellae must also be modified. 相似文献
240.
Jun-Ji Cao Chong-Shu Zhu Judith C. Chow John G. Watson Yong-Ming Han Ge-hui Wang Zhen-xing Shen Zhi-Sheng An 《Atmospheric Research》2009,94(2):194-202
Aerosol black carbon (BC) was measured every 5 min at Xi'an, China from September 2003 to August 2005. Daily BC concentrations ranged from 2 to 65 μg m− 3, averaging 14.7 ± 9.5 μg m− 3 and displayed clear summer minima and winter maxima. BC typically peaked between 0800 and 1000 LST and again between 2000 and 2200 LST, corresponding with morning and evening traffic combined with nighttime residential cooking and heating. The nocturnal peak was especially evident in winter, when more domestic heating is used and pollutant-trapping surface-inversions form earlier than in summer. BC frequency distributions the most commonly occurring concentrations occurred between 5 and 10 μg m− 3 in all four seasons. BC ranged from 1.6% and 15.6%, and averaged 8.3% of PM2.5. A clear inverse relationship between BC and wind speed (WS) was found when WS was below 2.5 to 3.0 m s− 1, implying a local origin for BC. Mixed layer depths (MLDs) were shallower during BC episodes compared to cleaner conditions. 相似文献