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51.
Center-to-limb observations of the Ki 7699 line made on 30 days over a five-year period using the McMath-Pierce Solar Telescope at Kitt Peak are presented. Both a relative and absolute limb effect have been derived from the data. Our determination of the limb effect in Ki 7699 shows a linear increase to the limb amounting to about 40 m s–1.Operated by the Association of Universities for Research in Astronomy, Inc. (AURA) under cooperative agreement with the National Science Foundation. 相似文献
52.
John D. Monnier Stefan Kraus Michael J. Ireland Fabien Baron Amelia Bayo Jean-Philippe Berger Michelle Creech-Eakman Ruobing Dong Gaspard Duchêne Catherine Espaillat Chris Haniff Sebastian Hönig Andrea Isella Attila Juhasz Lucas Labadie Sylvestre Lacour Stephanie Leifer Antoine Merand Ernest Michael Stefano Minardi Christoph Mordasini David Mozurkewich Johan Olofsson Claudia Paladini Romain Petrov Jörg-Uwe Pott Stephen Ridgway Stephen Rinehart Keivan Stassun Jean Surdej Theo ten Brummelaar Neal Turner Peter Tuthill Kerry Vahala Gerard van Belle Gautam Vasisht Ed Wishnow John Young Zhaohuan Zhu 《Experimental Astronomy》2018,46(3):517-529
The Planet Formation Imager (PFI, www.planetformationimager.org) is a next-generation infrared interferometer array with the primary goal of imaging the active phases of planet formation in nearby star forming regions. PFI will be sensitive to warm dust emission using mid-infrared capabilities made possible by precise fringe tracking in the near-infrared. An L/M band combiner will be especially sensitive to thermal emission from young exoplanets (and their disks) with a high spectral resolution mode to probe the kinematics of CO and H2O gas. In this paper, we give an overview of the main science goals of PFI, define a baseline PFI architecture that can achieve those goals, point at remaining technical challenges, and suggest activities today that will help make the Planet Formation Imager facility a reality. 相似文献
53.
E. Kraus 《International Journal of Earth Sciences》1927,18(4):263-298
Ohne Zusammenfassung 相似文献
54.
G. Kraus 《Mineralogy and Petrology》1963,8(3):335-360
Ohne ZusammenfassungMit 8 Textabbildungen 相似文献
55.
Lanzerotti L.J. Medford L.V. Maclennan C.G. Kraus J.S. Kappenman J. Radasky W. 《Solar physics》2001,204(1-2):351-359
The large solar activity in mid-July 2000 produced a severe geomagnetic storm at Earth during the last half of 15 July universal
time. The enhancements and changes in the ionosphere electrical current systems caused large geopotentials to be induced over
oceanic distances. Across the northern Atlantic, from New Jersey to near the French coast, a geopotential as large as 0.05 V km−1 (a peak-to-peak voltage of about 300 V) was measured during the geomagnetic storm. While large, this was not among the four
largest such geopotentials that have been recorded in the last 60 years across AT&T telecommunications cable routes, ocean
and continental. The geomagnetic and geopotential data that were measured during the storm event are presented and discussed. 相似文献
56.
Natural Hazards - Existing research indicates that distinct human populations may prepare for, experience, and recover from wildfires in different ways. However, research that helps explain... 相似文献
57.
Shan-Jie Qian A. Kraus Xi-Zhen Zhang T. P. Krichbaum A. Witzel J. A. Zensus National Astronomical Observatories Chinese Academy of Sciences Beijing Max-Planck-Institut fur Radioastronomie Auf dem Hugel Bonn Germany 《中国天文和天体物理学报》2002,2(4):325-346
We present a detailed analysis of multi-frequency observations of linear polarization in the intraday variable quasar 0917+624 (z = 1.44). The observations were made in May 1989 at five frequencies (1.4, 2.7, 5.0, 8.3 and 15GHz) with the VLA and the Effelsberg 100 m-telescope and in December 1988 at two frequencies (2.7 and 5.0 GHz) with the latter. It is shown that the relationship between the variations of the polarized and total flux density is highly wavelength dependent, and the multi-frequency polarization behavior may be essential for investigating the mechanisms causing these variations. It is shown that the variations observed at 20 cm can be interpreted in terms of refractive interstellar scintillation. However, after subtracting the variation due to scintillation, three 'features' emerged in the light-curve of the polarized flux density, indicating an additional variable component. Interestingly, these features are shown to be correlated with the variations at 2-6 cm, thus indicating that thes 相似文献
58.
Dave Craw Phaedra Upton Bing-Sheng Yu Travis Horton Yue-Gau Chen 《Mineralium Deposita》2010,45(7):631-646
Gold-bearing vein systems in the high mountains of Taiwan are part of the youngest tectonic-hydrothermal system on Earth.
Tectonic collision initiated in the Pliocene has stacked Eocene–Miocene marine sedimentary rocks to form steep mountains nearly
4 km high. Thinner portions of the sedimentary pile (∼5 km) are currently producing hydrocarbons in a fold and thrust belt,
and orogenic gold occurs in quartz veins in thicker parts of the pile (∼10 km) in the Slate Belt that underlies the mountains.
Metamorphic fluids (2–5 wt.% NaCl equivalent) are rising from the active greenschist facies metamorphic zone and transporting
gold released during rock recrystallisation. Metamorphic fluid flow at the Pingfengshan historic gold mine was focussed in
well-defined (4 km3) fracture zones with networks of quartz veins, whereas large surrounding volumes of rock are largely unveined. Gold and arsenopyrite
occur in several superimposed vein generations, with ankeritic alteration of host rocks superimposed on chlorite–calcite alteration
zones as fluids cooled and became out of equilibrium with the host rocks. Mineralising fluids had δ18O near +10‰, δ13C was between −1‰ and −6‰ and these fluids were in isotopic equilibrium with host rocks at ∼350°C. Ankeritic veins were emplaced
in extensional sites in kink fold axial surfaces, formed as the rock mass was transported laterally from compressional to
extensional regimes in the orogen. Rapid exhumation (>2 mm/year) of the Slate Belt is causing a widespread shallow conductive
thermal anomaly without igneous intrusions. Meteoric water is penetrating into the conductive thermal anomaly to contribute
to crustal fluid flow and generate shallow boiling fluids (∼250°C) with fluid temperature greater than rock temperature. The
meteoric-hydrothermal system impinges on, but causes only minor dilution of, the gold mineralisation system at depth. 相似文献
59.
Theo Brauers Hans-Peter Dorn Helmut Koch Annette B. Kraus Christian Plass-Dülmer 《Journal of Atmospheric Chemistry》1998,31(1-2):33-52
Meteorological data, ozone mixing ratios, and photolysis frequencies for the period August 2 to August 24, 1994, are presented and discussed in support of the field campaign POPCORN (Photochemistry of Plant Emitted Compounds and OH Radicals in Northeastern Germany). Measurements of temperature, ozone, and wind speed at different heights are used to evaluate micro-meteorological parameters. The observations provide information about local influences on the air mass composition. The analysis of radio sonde data of nearby stations provides the height of the planetary boundary layer. 相似文献
60.
Brightness and linear polarization measurements at 678.5 nm for four south-north strips of Jupiter are studied. These measurements were obtained in 1997 by the Galileo photopolarimeter/radiometer. The observed brightness exhibits latitudinal variations consistent with the belt/zone structure of Jupiter. The observed degree of linear polarization is small at low latitudes and increases steeply toward higher latitudes. No clear correlations were observed between the degree of linear polarization and the brightness. The observed direction of polarization changes from approximately parallel to the local scattering plane at low latitudes to perpendicular at higher latitudes. For our studies, we used atmospheric models that include a haze layer above a cloud layer. Parameterized scattering matrices were employed for the haze and cloud particles. On a pixel-wise basis, the haze optical thickness and the single-scattering albedo of the cloud particles were derived from the observed brightness and degree of linear polarization; results were accepted only if they were compatible with the observed direction of polarization. Using atmospheric parameter values obtained from Pioneer 10 and 11 photopolarimetry for the South Tropical Zone and the north component of the South Equatorial Belt, this analysis yielded acceptable results for very few pixels, particularly at small phase angles. However, for almost all pixels, acceptable results were found when the parameterized scattering matrix of the cloud particles was adjusted to produce more negative polarization for single scattering of unpolarized light, especially at large scattering angles, similar to some laboratory measurements of ammonia ice crystals. Using this adjusted model, it was found that the derived latitudinal variation of the single-scattering albedo of the cloud particles is consistent with the belt/zone structure, and that the haze optical thickness steeply increases toward higher latitudes. 相似文献