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31.
Kathy Whaler 《地学学报》1996,8(1):95-99
On 10 April 1995, during the EUG 8 meeting in Strasbourg, about 100 people gathered to participate in a Forum on Electronic Publishing, organized by Dominic Vaughan (Elsevier Science) and Kathy Whaler (University of Edinburgh and Royal Astronomical Society). In what follows, I have tried to convey a flavour of the style of the various presentations, as well as their content. Many points were reiterated by more than one speaker; in general, I have not repeated them. 相似文献
32.
An analysis of Titan's solar phase variation as a function of wavelength together with the continuum geometric albedo makes it possible to set limits on the real part of the refractive index and on the average particle size of the aerosol component of Titan's atmosphere: . If nris known can be determined to within a few percent, and varies inversely with nr. Using this information in a two-layer model of a methane-aerosol atmosphere and comparing the result with Titan's visible and near-infrared methane spectrum leads to the conclusion that the top layer of Titan's atmosphere contains 0.01 km atm of methane and 2.5 extinction optical depths of aerosol, while the data are consistent with a bottom layer containing 2.2 km atm of methane and about 7.5 aerosol optical depths for . 相似文献
33.
An analysis of available observations of the April 7, 1968 occultation of BD ?17° 4388 by Neptune yields upper atmosphere temperatures of ~140°K near the 5 × 1014cm?3 level. The temperature structure of the atmosphere at these levels is complicated and nonisothermal. Diurnal temperature variations are certainly less than 10°K and may be absent. The average temperature decreases by less than 15°K between 0° and 55° latitude. 相似文献
34.
Pressure‐driven,shoreline currents in a perennially ice‐covered,pro‐glacial lake in Antarctica,identified from a LiCl tracer injected into a pro‐glacial stream 下载免费PDF全文
The distribution of streamwater within ice‐covered lakes influences sub‐ice currents, biological activity and shoreline morphology. Perennially ice‐covered lakes in the McMurdo Dry Valleys, Antarctica, provide an excellent natural laboratory to study hydrologic–limnologic interactions under ice cover. For a 2 h period on 17 December 2012, we injected a lithium chloride tracer into Andersen Creek, a pro‐glacial stream flowing into Lake Hoare. Over 4 h, we collected 182 water samples from five stream sites and 15 ice boreholes. Geochemical data showed that interflow travelled West of the stream mouth along the shoreline and did not flow towards the lake interior. The chemistry of water from Andersen Creek was similar to the chemistry of water below shoreline ice. Additional evidence for Westward flow included the morphology of channels on the ice surface, the orientation of ripple marks in lake sediments at the stream mouth and equivalent temperatures between Andersen Creek and water below shoreline ice. Streamwater deflected to the right of the mouth of the stream, in the opposite direction predicted by the Coriolis force. Deflection of interflow was probably caused by the diurnal addition of glacial runoff and stream discharge to the Eastern edge of the lake, which created a strong pressure gradient sloping to the West. This flow directed stream momentum away from the lake interior, minimizing the impact of stream momentum on sub‐ice currents. It also transported dissolved nutrients and suspended sediments to the shoreline region instead of the lake interior, potentially affecting biological productivity and bedform development. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
35.
We present observations of Uranus taken with the near-infrared camera NIRC2 on the 10-m W.M. Keck II telescope, the Wide Field Planetary Camera 2 (WFPC2) and the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST) from July 2007 through November 2009. In this paper we focus on a bright southern feature, referred to as the “Berg.” In Sromovsky et al. (Sromovsky, L.A., Fry, P.M., Hammel, H.B., Ahue, A.W., de Pater, I., Rages, K.A., Showalter, M.R., van Dam, M. [2009]. Icarus 203, 265-286), we reported that this feature, which oscillated between latitudes of −32° and −36° for several decades, suddenly started on a northward track in 2005. In this paper we show the complete record of observations of this feature’s track towards the equator, including its demise. After an initially slow linear drift, the feature’s drift rate accelerated at latitudes ∣θ∣ < 25°. By late 2009 the feature, very faint by then, was spotted at a latitude of −5° before disappearing from view. During its northward track, the feature’s morphology changed dramatically, and several small bright unresolved features were occasionally visible poleward of the main “streak.” These small features were sometimes visible at a wavelength of 2.2 μm, indicative that the clouds reached altitudes of ∼0.6 bar. The main part of the Berg, which is generally a long sometimes multipart streak, is estimated to be much deeper in the atmosphere, near 3.5 bars in 2004, but rising to 1.8-2.5 bars in 2007 after it began its northward drift. Through comparisons with Neptune’s Great Dark Spot and simulations of the latter, we discuss why the Berg may be tied to a vortex, an anticyclone deeper in the atmosphere that is visible only through orographic companion clouds. 相似文献
36.
Garrit Voggesser Kathy Lynn John Daigle Frank K. Lake Darren Ranco 《Climatic change》2013,120(3):615-626
Climate change related impacts, such as increased frequency and intensity of wildfires, higher temperatures, extreme changes to ecosystem processes, forest conversion and habitat degradation are threatening tribal access to valued resources. Climate change is and will affect the quantity and quality of resources tribes depend upon to perpetuate their cultures and livelihoods. Climate impacts on forests are expected to directly affect culturally important fungi, plant and animal species, in turn affecting tribal sovereignty, culture, and economy. This article examines the climate impacts on forests and the resulting effects on tribal cultures and resources. To understand potential adaptive strategies to climate change, the article also explores traditional ecological knowledge and historical tribal adaptive approaches in resource management, and contemporary examples of research and tribal practices related to forestry, invasive species, traditional use of fire and tribal-federal coordination on resource management projects. The article concludes by summarizing tribal adaptive strategies to climate change and considerations for strengthening the federal-tribal relationship to address climate change impacts to forests and tribal valued resources. 相似文献
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The low-redshift IGM probes the last ten billion years of metal enrichment from galactic feedback processes. We present preliminary results from a survey of intergalactic metal-line absorption systems in archival HST STIS, GHRS, and FUSE spectra of ≈50 z?2 UV-bright objects. We summarize the detailed analysis of one sightline (PKS1302–102, z QSO =0.2784) with which we set the methodology for the larger survey. We use simple CLOUDY models to constrain the ionizing mechanism(s) and metallicities for the metal-line systems. For about 15 sightlines, including PKS1302–102, we have a complementary galaxy survey, and we look for correlations between galaxies and absorption systems in order to understand the large-scale distribution of the metal-enriched IGM. 相似文献
40.
Ronald E. Stewart Daniel Betancourt James B. Davies Deborah Harford Yaheli Klein Robert Lannigan Linda Mortsch Erin O’Connell Kathy Tang Paul H. Whitfield 《Natural Hazards》2017,87(2):791-815
Using studies of places where heat waves are common, projected changes in heat waves in Metro Vancouver are assessed from a multi-disciplinary perspective with respect to the potential impacts of the physical change on the people and infrastructure with the intention of being better prepared for future events. Trends in maximum temperature parameters for Metro Vancouver for the past 75 years are generally not statistically significant; however, projections for 2041–2060 and 2081–2100 suggest that the region will experience such events more frequently in the future due to climate change. While Metro Vancouver, British Columbia (BC) generally does not typically experience heat waves it was strongly affected by a major heat event in July 2009, with temperature records being broken at Vancouver (≥31 °C) on the coast and at Abbotsford (≥36 °C) 65-km inland. A lack of sea breeze during this event meant that there was no cooling effect, and land surface temperatures over the downtown area approached 40 °C and excess deaths occurred. Many victims were either in the 65–74 age category, the vulnerable poor, or people with mental health issues. Because these events are rare, many buildings lack air-conditioning, and residents of Metro Vancouver under-anticipate their vulnerability. The costs of health-related impacts outweighed those related to higher electricity usage. 相似文献