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101.
O. A. Jones A. F. Wilson J. F. G. Wilkinson W. G. H. Maxwell D. Hill A. F. Wilson 《Australian Journal of Earth Sciences》2013,60(2):202-203
F. L. Stillwell Anniversary Volume. Australian Institute of Mining and Metallurgy, Melbourne, 302 pages, many plates and figures. 1958. Our Mineral Resources, by Charles M. Riley; x + 338 pages; 102 figures; John Wiley and Sons, Inc., New York and London. $6.95. Researches in Geochemistry, edited by P. H. Abelson; John Wiley and Sons Inc., New York, 1959. $11.00. Basic Geology for Science and Engineering, by Edward C. Dapples; vii + 609 pages; 231 figures. John Wiley and Sons Inc., New York, 1959. $9.50. Historical Geology, by Carl O. Dunbar; xi + 500 pages; 406 figures. Second Edition, publication date August, 1960; John Wiley and Sons Inc., New York. $7.95. Time, Life and Man, by R. A. Stirton; xi + 558 pages; 291 figures. John Wiley and Sons Inc., New York, 1958. Vector Space, by Martin J. Buerger; xiv + 347 pages; numerous line drawings; John Wiley and Sons Inc., New York and London. $12.00. Geology of the Country Around Polonnaruwa, by Piyadasa W. Vtkanage. 1959. Memoir No. 1, Department of Mineralogy, Geological Survey of Ceylon; ix + 75 pages; 11 figures; 12 plates. 相似文献
102.
M. R. Cunningham P. A. Jones P. D. Godfrey D. M. Cragg I. Bains M. G. Burton P. Calisse N. H. M. Crighton S. J. Curran T. M. Davis J. T. Dempsey B. Fulton M. G. Hidas T. Hill L. Kedziora-Chudczer V. Minier M. B. Pracy C. Purcell J. Shobbrook T. Travouillon 《Monthly notices of the Royal Astronomical Society》2007,376(3):1201-1210
We have used the Mopra Telescope to search for glycine and the simple chiral molecule propylene oxide in the Sgr B2 (LMH) and Orion KL, in the 3-mm band. We have not detected either species, but have been able to put sensitive upper limits on the abundances of both molecules. The 3σ upper limits derived for glycine conformer I are 3.7 × 1014 cm−2 in both Orion-KL and Sgr B2 (LMH), comparable to the reported detections of conformer I by Kuan et al. However, as our values are 3σ upper limits rather than detections we conclude that this weighs against confirming the detection of Kuan et al. We find upper limits for the glycine II column density of 7.7 × 1012 cm−2 in both Orion-KL and Sgr B2 (LMH), in agreement with the results of Combes et al. The results presented here show that glycine conformer II is not present in the extended gas at the levels detected by Kuan et al. for conformer I. Our ATCA results have ruled out the detection of glycine (both conformers I and II) in the compact hot core of the LMH at the levels reported, so we conclude that it is unlikely that Kuan et al. have detected glycine in either Sgr B2 or Orion-KL. We find upper limits for propylene oxide abundance of 3.0 × 1014 cm−2 in Orion-KL and 6.7 × 1014 cm−2 in Sgr B2 (LMH). We have detected fourteen features in Sgr B2 and four features in Orion-KL which have not previously been reported in the interstellar medium, but have not been able to plausibly assign these transitions to any carrier. 相似文献
103.
104.
R.E. Johnson J.G. Luhmann M. Bouhram E.C. Sittler T.W. Hill M. Michael M. Liu D.T. Young 《Icarus》2006,180(2):393-402
Molecular oxygen produced by the decomposition of icy surfaces is ubiquitous in Saturn's magnetosphere. A model is described for the toroidal O2 atmosphere indicated by the detection of and O+ over the main rings. The O2 ring atmosphere is produced primarily by UV photon-induced decomposition of ice on the sunlit side of the ring. Because O2 has a long lifetime and interacts frequently with the ring particles, equivalent columns of O2 exist above and below the ring plane with the scale height determined by the local ring temperature. Energetic particles also decompose ice, but estimates of their contribution over the main rings appear to be very low. In steady state, the O2 column density over the rings also depends on the relative efficiency of hydrogen to oxygen loss from the ring/atmosphere system with oxygen being recycled on the grain surfaces. Unlike the neutral density, the ion densities can differ on the sunlit and shaded sides due to differences in the ionization rate, the quenching of ions by the interaction with the ring particles, and the northward shift of the magnetic equator relative to the ring plane. Although O+ is produced with a significant excess energy, is not. Therefore, should mirror well below those altitudes at which ions were detected. However, scattering by ion-molecule collisions results in much larger mirror altitudes, in ion temperatures that go through a minimum over the B-ring, and in the redistribution of both molecular hydrogen and oxygen throughout the magnetosphere. The proposed model is used to describe the measured oxygen ion densities in Saturn's toroidal ring atmosphere and its hydrogen content. The oxygen ion densities over the B-ring appear to require either significant levels of UV light scattering or ion transmission through the ring plane. 相似文献
105.
We study the temporal variation of subsurface flows of 788 active regions and 978 quiet regions. The vertical-velocity component
used in this study is derived from the divergence of the measured horizontal flows using mass conservation. The horizontal
flows cover a range of depths from the surface to about 16 Mm and are determined by analyzing about five years of GONG high-resolution
Doppler data with ring-diagram analysis. We determine the change in unsigned magnetic flux during the disk passage of each
active region using MDI magnetograms binned to the ring-diagram grid. We then sort the data by their flux change from decaying
to emerging flux and divide the data into five subsets of equal size. The average vertical flows of the emerging-flux subset
are systematically shifted toward upflows compared to the grand average values of the complete data set, whereas the average
flows of the decaying-flux subset show comparably more pronounced downflows especially near 8 Mm. For flux emergence, upflows
become stronger with time with increasing flux at depths greater than about 10 Mm. At layers shallower than about 4 Mm, the
flows might start to change from downflows to upflows, when flux emerges, and then back to downflows after the active regions
are established. The flows in the layers between these two depth ranges show no response to the emerging flux. In the case
of decaying flux, the flows change from strong upflows to downflows at depths greater than about 10 Mm, whereas the flows
do not change systematically at other depths. A cross-correlation analysis shows that the flows in the near-surface and the
deeper layers might change about one day before flux emerges. The flows associated with the quiet regions fluctuate with time
but do not show any systematic variation. 相似文献
106.
Frank Hill Piet Martens Keji Yoshimura Joseph Gurman Joseph Hourclé George Dimitoglou Igor Suárez-Solá Steve Wampler Kevin Reardon Alisdair Davey Richard S. Bogart Karen Q. Tian 《Earth, Moon, and Planets》2009,104(1-4):315-330
The Virtual Solar Observatory (VSO) has been developed to allow researchers, educators, and the general public to access data and images from the major sources of on-line solar data. The VSO substantially reduces the effort required to locate disparate data sets, and removes the need for the user to locate the data and learn multiple interfaces. The VSO provides a single interface to about 60 geographically distributed data sets including space- and ground-based sources. These data sets incorporate several physical variables including magnetic field, intensity, Doppler velocity, etc., and all wavelengths from X-ray to radio. All layers of the sun, from the interior to the corona, are included. In this paper we describe the system and present the interface that the user will encounter. We also discuss future enhancements planned for the system. 相似文献
107.
Paul M. Winkler Anca Hienola Gerhard Steiner Gerard Hill Aron Vrtala Georg P. Reischl Markku Kulmala Paul E. Wagner 《Atmospheric Research》2008,90(2-4):187-ICNAA07
Heterogeneous nucleation of supersaturated n-nonane vapour on seed particles of different size and composition has been investigated using a fast expansion chamber. Monodisperse seed particle sizes were ranging from about 4 nm up to about 24 nm in diameter. By using different types of particle generators WOx, Ag and (NH4)2SO4 particles were generated. For direct comparison between different particle compositions overlapping sizes have been generated for WOx and Ag at about 7 nm particle diameter as well as for Ag and (NH4)2SO4 at about 15 nm. Nucleation temperature was kept constant at about 278 K. Experimental data were compared to Kelvin equation and Fletcher theory including the effect of line tension. It was found that heterogeneous nucleation of n-nonane seems to be independent of seed particle composition and starts well below the Kelvin curve. Good agreement was achieved with Fletcher theory including the effect of line tension. 相似文献
108.
Dalia Bach Kirschbaum Robert Adler Yang Hong Stephanie Hill Arthur Lerner-Lam 《Natural Hazards》2010,52(3):561-575
A systematic inventory of landslide events over the globe is valuable for estimating human and economic losses, quantifying
the relationship between landslide occurrences and climate variations and for evaluating emerging global landslide prediction
efforts based on remote sensing data. This study compiles a landslide catalog for rainfall-triggered events for several years,
drawing upon news reports, scholarly articles, and other hazard databases to provide a landslide catalog at the global scale.
While this database may only represent a subset of rainfall-triggered landslides globally, due to lack of reports, it presents
a lower boundary on the number of events globally and provides initial insight into the spatiotemporal statistical trends
in landslide distribution and impact. This article develops a methodology for landslide event compilation that can be used
in evaluating global landslide forecasting initiatives and assessing patterns in landslide distribution and frequency worldwide. 相似文献
109.
A.J. Coates G.H. Jones G.R. Lewis A. Wellbrock D.T. Young R.E. Johnson T.W. Hill 《Icarus》2010,206(2):618-622
During Cassini’s Enceladus encounter on 12th March 2008, the Cassini Electron Spectrometer, part of the CAPS instrument, detected fluxes of negative ions in the plumes from Enceladus. It is thought that these ions include negatively charged water group cluster ions associated with the plume and forming part of the ‘plume ionosphere’. In this paper we present our observations, argue that these are negative ions, and present preliminary mass identifications. We also suggest mechanisms for production and loss of the ions as constrained by the observations. Due to their short lifetime, we suggest that the ions are produced in or near the water vapour plume, or from the extended source of ice grains in the plume. We suggest that Enceladus now joins the Earth, Comet Halley and Titan as locations in the Solar System where negative ions have been directly observed although the ions observed in each case have distinctly different characteristics. 相似文献
110.
Victorian farmers have experienced significant impact from climate change associated with drought and more recently flooding. These factors form a convergence with a complex of other factors to change production systems physically; and farmers’ decision making is variously described as adaptive or maladaptive to these drivers of change. Recently updated State Government policies on farming, climate and water have immediate and long term implications for food production systems but are not readily interpreted at a local scale. Further, peak oil and energy security are only partially integrated into either climate or water policy discourse. In effect, despite some far-sighted words about the meaning of climate change, uncertainty is largely met with a ‘business as usual’ mantra. Farmer narratives are used to demonstrate their systemic and increasing vulnerability and likelihood of perverse outcomes. The Future Farming strategy and Our Water Our Future are briefly analyzed, as are potential implications of the rhetoric of newly elected conservative government. Using ideas from Bourdieu and Bhabha we suggest that the reliance on farmers being able to innovate and take up opportunities associated with the uncertainty of large scale changes in climate and energy availability are misguided. It is more likely that current policy directions entrench the values of the global market and its elite, leaving farmers locked-in to historical structural responses that will not be successful in the long-term and will diminish their ability to imagine radical and diverse ways of avoiding the maladaptive structures currently surrounding their production systems. 相似文献