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141.
M. A. Barstow M. R. Burleigh N. J. Bannister J. S. Lapington M. P. Kowalski R. G. Cruddace K. S. Wood F. Auchere M. F. Bode G. E. Bromage B. Gibson A. C. Cameron A. Cassatella F. Delmotte M.-F. Ravet J. G. Doyle C. S. Jeffery B. Gaensicke C. Jordan N. Kappelmann K. Werner R. Lallement D. de Martino S. A. Matthews K. J. H. Phillips G. Del Zanna M. Orio E. Pace I. Pagano J. H. M. M. Schmitt B. Y. Welsh 《Astrophysics and Space Science》2009,320(1-3):231-238
This paper describes a proposed high resolution soft X-ray and Extreme Ultraviolet (EUV) spectroscopy mission to carry out a survey of Stellar and Galactic Environments (SAGE). The payload is based on novel diffraction grating technology which has already been proven in a sub-orbital space mission and which is ready to fly on a satellite platform with minimal development. Much of the technical detail of the instrumentation has been reported elsewhere and we concentrate our discussion here on the scientific goals of a SAGE base-line mission, demonstrating the scientific importance of high resolution spectroscopy in the Extreme Ultraviolet for the study of stars and the local interstellar medium. 相似文献
142.
M. A. Barstow M. P. Kowalski R. G. Cruddace K. S. Wood F. Auchere N. J. Bannister M. F. Bode G. E. Bromage M. R. Burleigh A. C. Cameron A. Cassatella F. Delmotte J. G. Doyle B. Gaensicke B. Gibson C. S. Jeffery C. Jordan N. Kappelmann R. Lallement J. S. Lapington D. de Martino S. A. Matthews M. Orio E. Pace I. Pagano K. J. H. Phillips M.-F. Ravet J. H. M. M. Schmitt B. Y. Welsh K. Werner G. Del Zanna 《Experimental Astronomy》2009,23(1):169-191
This paper describes a proposed high resolution soft X-ray and Extreme Ultraviolet spectroscopy mission to carry out a survey
of Stellar and Galactic Environments (SAGE). The payload is based on novel diffraction grating technology which has already
been proven in a sub-orbital space mission and which is ready to fly on a satellite platform with minimal development. We
discuss the goals of a SAGE base-line mission and demonstrate the scientific importance of high resolution spectroscopy in
the Extreme Ultraviolet for the study of stars and the local interstellar medium. 相似文献
143.
Multi-level, networked participation is a vital component in building social–ecological resilience and the capacity to adapt to environmental change. This paper outlines the ways in which multi-level participation contributes to adaptive capacity and, in so doing, takes a step toward articulating a theory of participation based on resilience thinking. We use a case study of Gabra pastoralist communities of northern Kenya to illustrate how multi-level participation may lead to increasing adaptive capacity, above and beyond existing pastoralist adaptations. The findings suggest that adaptive capacity is systemic—that is to say, it is a property of the social–ecological system, including especially the network of institutional linkages that characterizes that system, as much as it is a property of particular actors within the system. We argue that there are three key elements of meaningful multi-level participation: an institutional environment in which the various levels of institutions are linked, inclusivity in decision-making at these various levels, and deliberation. These three features can work together to create meaningful multi-level participation, to facilitate the co-production of knowledge and to build adaptive capacity. 相似文献
144.
145.
Lance A. M. Benner Steven J. Ostro Michael C. Nolan Jean‐Luc Margot Jon D. Giorgini R. Scott Hudson Raymond F. Jurgens Martin A. Slade Ellen S. Howell Donald B. Campbell Donald K. Yeomans 《Meteoritics & planetary science》2002,37(6):779-792
Abstract— We report results of delay‐Doppler observations of 1999 JM8 with the Goldstone 8560 MHz (3.5 cm) and Arecibo 2380 MHz (13 cm) radars over 18 days in July‐August 1999. The images place thousands of pixels on the asteroid and achieve range resolutions as fine as 15 m/pixel. The images reveal an asymmetric, irregularly shaped object with a typical overall dimension within 20% of 7 km. If we assume that 1999 JM8's effective diameter is 7 km, then the absolute magnitude, 15.15, and the average Goldstone radar cross section, 2.49 km2, correspond to optical and radar albedos of 0.02 and 0.06, establishing that 1999 JM8 is a dark object at optical and radar wavelengths. The asteroid is in a non‐principal axis spin state that, although not yet well determined, has a dominant periodicity of ?7 days. However, images obtained between July 31 and August 9 show apparent regular rotation of features from day to day, suggesting that the rotation state is not far from principal axis rotation. 1999 JM8 has regions of pronounced topographic relief, prominent facets several kilometers in extent, numerous crater‐like features between ?100 m and 1.5 km in diameter, and features whose structural nature is peculiar. Arecibo images provide the strongest evidence to date for a circular polarization ratio feature on any asteroid. Combined optical and radar observations from April 1990 to December 2000 permit computation of planetary close approach times to within ± 10 days over the interval from 293 to at least 2907, one of the longest spans for any potentially hazardous asteroid. Integration of the orbit into the past and future shows close approaches to Earth, Mars, Ceres, and Vesta, but the probability of the object impacting Earth is zero for at least the next nine centuries. 相似文献
146.
147.
Acta Geotechnica - The intergranular strain concept (IGS) and intergranular strain anisotropy formulation (ISA) are state of the art extensions to describe small-strain effects. The main... 相似文献
148.
Marie Noël Lance Barrett-Lennard Christophe Guinet Neil Dangerfield Peter S. Ross 《Marine environmental research》2009,68(4):196-202
Persistent organic pollutants (POPs), including polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), and dibenzofurans (PCDFs), are ubiquitous environmental contaminants of which significant concentrations are reported in upper trophic level animals. In 1998, we collected blubber biopsy samples (n = 11) from killer whales (Orcinus orca) inhabiting the coastal waters around Possession Island, Crozet Archipelago, southern Indian Ocean, for contaminant analyses. Despite inhabiting an isolated region far removed from industrial activities, these killer whales can presently be considered among the most PCB-contaminated cetaceans in the southern hemisphere, with concentrations ranging from 4.4 to 20.5 mg/kg lipid weight (lw). PCDD levels ranged from below the detection limit (5 ng/kg) to 77.1 ng/kg lw and PCDF levels from below the detection limit (7 ng/kg) to 36.1 ng/kg lw. Over 70% of our study animals had PCB concentrations which exceeded a 1.3 mg/kg PCB threshold established for endocrine disruption and immunotoxicity in free-ranging harbour seals, suggesting that organic contaminants cannot be ruled out as an additional threat to this declining population. 相似文献
149.
Dcr δ Scuti Stem HD 181 333 wurde im Sommer 1979 in drei NHchten mit dem Z\villi, ngstelrskop im irbu-System beobachtet. Es konnte eine Periode von 0.1277 Tagen bestimmt werden. The δ Scuti star HD 181 333 was observed in summer 1979 during thrce nights with the twin telescope in rrbu-system. A period of 0.1277 days was found. 相似文献
150.
S. K. Watson S. P. S. Eyres R. J. Davis M. F. Bode A. M. S. Richards H. T. Kenny 《Monthly notices of the Royal Astronomical Society》2000,311(3):449-455
We present MERLIN observations of the symbiotic nova V1016 Cygni made at 6 cm between 1992 and 1997 and at 18 cm in 1993 and 1997. In the 6-cm images we find complex structure which has not been previously seen, in particular three bright components. These components do not appear to be expanding as would be expected from the remains of a hot wind resulting from the nova outburst. The change in positions of two of the features exhibits tentative east–west movement. The brightness temperature of the peak with the highest flux density remains above 50 000 K in all epochs, thereby confirming the presence of shocked material in the system. At 18 cm there is no evidence of any non-thermal emission as might be expected from comparison with a sister star, HM Sge. 相似文献