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41.
Functional roles of interzonal migrating mesozooplankton in the western subarctic Pacific 总被引:1,自引:0,他引:1
Grazing experiments and production estimation based on life-history analysis of Neocalanus copepods (N. cristatus, N. plumchrus and N. flemingeri) were carried out in the Oyashio region to understand the carbon flows associated with the interzonal migrating copepods. These copepods, and also Eucalanus bungii, fed on nano- and micro-sized organisms non-selectively throughout the season. However, diatoms were the dominant food resource until May and organisms, such as ciliates were the major resource after May. Daily growth rate was estimated from the Ikeda–Motoda, Huntley–Lopez and Hirst–Sheader models. Since the growth rates were considered to be overestimates for the Huntley–Lopez model and underestimates for the other two models, we applied the weight-specific growth rates previously reported for these species in the Bering Shelf. Surface biomass of Neocalanus increased rapidly in June during the appearance of C5, and a successive increase of overwintering stock was evident in the deeper layer. The deep biomass decreased gradually from September to May during the dormant and reproduction period. N. cristatus has the largest annual mean biomass (2.3 gC m−2), followed by N. plumchrus (1.1) and N. flemingeri (0.4). Daily production rate of Neocalanus varied from 0.4 to 363.4 mgC m−2 day−1, to which N. cristatus was the largest contributor. Annual production was estimated as 11.5 gC m−2 year−1 for N. cristatus, 5.7 for N. plumchrus and 2.1 for N. flemingeri, yielding annual P/B ratio of 5 for each species. The annual production of Neocalanus accounted for 13.2% of the primary production in the Oyashio region. Their fecal pellets were estimated to account for 14.9% (0.7 gC m−2 year−1) of sinking flux of organic carbon at 1000-m depth. Moreover, their export flux by ontogenetic vertical migration, which is not measured by sediment trap observations, is estimated to be 91.5% (4.3 gC m−2 year−1) of carbon flux of sinking particles at 1000-m depth. These results suggest the important role of interzonal migrating copepods in the export flux of carbon. 相似文献
42.
《Norsk geografisk tidsskrift. Norwegian journal of geography》2012,66(3):199-206
Outdoor recreation policy and management have largely been occupied by questions related to use patterns: who participates in which activities, where and when? However, it is commonly held that ideas and practices mutually influence each other. In outdoor recreation, it could be expected that the observable use patterns are influenced by the meaning recreationists ascribe to their activities. In this study 14 narratives of outdoor recreation practices are analyzed, in order to broaden the traditional understanding of the meaning of outdoor recreation. 相似文献
43.
Production and R&D networks of foreign ventures in China: Implications for technological dynamism and regional development 总被引:2,自引:0,他引:2
This paper analyzes the nature of FDI local networks in production and R&D activities in China and discusses their implications for technological dynamism and regional development. We investigate foreign ventures (or foreign-invested enterprises, FIEs) in the information and communication technology (ICT) industry, based on a large-scale survey of ICT firms conducted in three mega-city regions of China: Beijing, Shanghai-Suzhou, and Shenzhen-Dongguan. Our data show that FIEs in China are gradually localizing their production, but the extent of local embeddedness is contingent upon home country effects, local specific contexts and FDI-host region relationships. We have also found significant influence of industrial agglomeration on FDI location and network decisions. Beijing tends to have broader FDI sources and better integrated global-local networks, while in those regions dominated by FDI such as Suzhou and Dongguan, FIEs are thinly embedded with local economies and tend to establish global-local networks among themselves; local embeddedness is limited by a series of technological, institutional, spatial, and structural mismatches. Shanghai and Shenzhen are in between. More efforts are still needed to better integrate FDI with local economies and strengthen China’s local innovative capacities. 相似文献
44.
Solar flare gamma-ray emissions from energetic ions and electrons have been detected and measured to GeV energies since 1980. In addition, neutrons produced in solar flares with 100 MeV to GeV energies have been observed at the Earth. These emis-sions are produced by the highest energy ions and electrons accelerated at the Sun and they provide our only direct (albeit secondary) knowledge about the properties of the acceler-ator(s) acting in a solar flare. The solar flares, which have direct evidence for pion-decaygamma-rays, are unique and are the focus of this paper. We review our current knowl-edge of the highest energy solar emissions, and how the characteristics of the acceleration process are deduced from the observations. Results from the RHESSI, INTEGRAL and CORONAS missions will also be covered. The review will also cover the solar flare ca-pabilities of the new mission, FERMI GAMMA RAY SPACE TELESCOPE, launched on 2008 June 11. Finally, we discuss the requirements for future missions to advance this vital area of solar flare physics. 相似文献
45.
<正>People'sRepublicofChinaisoneofthemostrapidlydevelopingcountriesintheworldtoday.Thereisagreatdemandonhighlyactualandaccuratespatialinformationofthewholecountry,especiallyofWestChinawhichbecomesthefocusofdevelopmentoftheChinesegovernmentrightnowandinthenextyears,butwherestillnotenoughtopographicmapsareavailable.ThisraisesgreatchallengestothesurveyingandmappingcommunityinChina.FacingthenewchallengestheChineseAcademyofSurveyingandMapping(CASM)starteditspioneerworkearly2002toexplorenewtechniquesandtechnologiesavailabletodaytowardincreasingthemapproductivity.WithimportofaCCNS/AEROcontrolsysteminNovember2002,thefirstDGPS/IMU-basedphotogrammetricprojectinChinawassuccessfullyaccomplishedjointlybyCASM,theGermany-basedcompaniesIGIandTechedge.Twophotogrammetricblocksof1:4,000and1:20,000photoscales,respectively,wereflowninAnyang,China.Directgeoreferencingandintegratedsensororientationwereconducted.Resultsachievedwereprovenbyusinggroundcheckpointsandcomparedwiththoseofaerialtriangulation.Orthophotosgeneratedbasedondir 相似文献
46.
Constructing quality: The multinational histories of chocolate 总被引:1,自引:0,他引:1
Geographic research on food quality, while considering many of the ways in which quality is socially constructed, has largely focused on the place-based aspects of the raw materials of food production. Here, we use French convention theory to look at a highly processed food in order to show how place associations in the social construction of food quality extend to manufacturing. For chocolate, quality is based on material characteristics whose relative importance in determining quality depends on the country in which different stages of economic innovation took place. Struggles over the definition of quality chocolate, as exemplified by the “European Chocolate War,” show how quality issues are connected to geographies of manufacturing and innovation. 相似文献
47.
根据察尔汗盐湖别勒滩卤水等温蒸发试验数据,结合大量生产取样分析资料,对盐田光卤石矿生产机理及其控制因素作了分析研究,并提出了管理措施。 相似文献
48.
Synthesis of available data allows us to define general patterns of late Quaternary carbonate production and sedimentation
in the global ocean. During high stands of sea level, the neritic and pelagic environments appear to sequester approximately
similar amounts of carbonate, whereas during low stands of sea level the decreased neritic zone produces and accumulates approximately
an order of magnitude less carbonate. Assuming that global accumulation of deep-sea carbonates remains more or less constant
during glacially induced changes in sea level, the ocean becomes depleted with respect to calcium carbonate during high stands
and recharges during low stands. Before we can achieve a better understanding of the global carbonate system, however, we
need a better understanding of key environments and processes: (a) production and accumulation on continental shelves both
as potential sinks (accumulation) and as sources (export to the deep sea); (b) a better measure of pelagic carbonate production;
and (c) late Quaternary (late Pleistocene and Holocene) mass accumulation rates in the deep sea. 相似文献
49.
农业气象与我国热区名特优水果生产 总被引:8,自引:0,他引:8
龙眼、荔枝和果是我国热带、南亚热带(简称热区)名特优水果.这些水果的花芽分化、开花座果对气象条件要求较严格。本文在分析龙眼、荔枝和果的主要气候生态特性的基础上,结合有关省区的气候资料,作出龙眼、荔枝和果生产的布局区划。 相似文献
50.