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51.
A. Collier Cameron D. M. Wilson R. G. West L. Hebb X.-B. Wang S. Aigrain F. Bouchy D. J. Christian W. I. Clarkson B. Enoch M. Esposito E. Guenther C. A. Haswell G. Hébrard C. Hellier K. Horne J. Irwin S. R. Kane B. Loeillet T. A. Lister P. Maxted M. Mayor C. Moutou N. Parley D. Pollacco F. Pont D. Queloz R. Ryans I. Skillen R. A. Street S. Udry P. J. Wheatley 《Monthly notices of the Royal Astronomical Society》2007,380(3):1230-1244
52.
D. J. Christian D. L. Pollacco I. Skillen R. A. Street F. P. Keenan W. I. Clarkson A. Collier Cameron S. R. Kane T. A. Lister R. G. West B. Enoch A. Evans A. Fitzsimmons C. A. Haswell C. Hellier S. T. Hodgkin K. Horne J. Irwin A. J. Norton J. Osborne R. Ryans P. J. Wheatley D. M. Wilson 《Monthly notices of the Royal Astronomical Society》2006,372(3):1117-1128
53.
D. Pollacco I. Skillen A. Cameron D. Christian J. Irwin T. Lister R. Street R. West W. Clarkson N. Evans A. Fitzsimmons C. Haswell C. Hellier S. Hodgkin K. Horne B. Jones S. Kane F. Keenan A. Norton J. Osborne R. Ryans P. Wheatley 《Astrophysics and Space Science》2006,304(1-4):253-255
The WASP project and infrastructure supporting the SuperWASP Facility are described. As the instrument, reduction pipeline and archive system are now fully operative we expect the system to have a major impact in the discovery of bright exo-planet candidates as well in more general variable star projects. 相似文献
54.
Gilbert R.W. Zedler E.A. Grilli S.T. Street R.L. 《Oceanic Engineering, IEEE Journal of》2007,32(1):236-248
In this paper, we report on the use of a numerical wave tank (NWT), based on fully nonlinear potential flow (FNPF) equations, in driving simulations of flow and sediment transport around partially buried obstacles. The suspended sediment transport is modeled in the near-field in a Navier-Stokes (NS) model using an immersed-boundary method and an attached sediment transport simulation module. Turbulence is represented by large eddy simulation (LES). The NWT is based on a higher order boundary element method (BEM), with an explicit second-order time stepping. Hence, only the NWT boundary is discretized. The solution for the velocity potential and its derivatives along the boundary is obtained in the BEM, which subsequently provides a solution at any required internal point within the domain. At initial time, the NS-LES model domain is initialized with the 3-D velocity field provided by the NWT and driven for later time by the pressure gradient field obtained in the NWT. Incident wave fields, as specified in the NWT to drive sediment transport, can be arbitrary. Applications are presented here for single frequency waves, such as produced by a harmonic piston wavemaker in the laboratory, and modulated frequency wave groups. The feasibility of coupling the irrotational flow and NS solutions is demonstrated. 相似文献
55.
R. A. Street D. J. Christian W. I. Clarkson A. Collier Cameron B. Enoch S. R. Kane T. A. Lister R. G. West D. M. Wilson A. Evans A. Fitzsimmons C. A. Haswell C. Hellier S. T. Hodgkin K. Horne J. Irwin F. P. Keenan A. J. Norton J. Osborne D. L. Pollacco R. Ryans I. Skillen P. J. Wheatley J. Barnes 《Monthly notices of the Royal Astronomical Society》2007,379(2):816-832
56.
Previous studies have demonstrated long‐term changes in effective moisture in sub‐Saharan Africa. Here, we reconstruct Holocene environments using a ~7 m lake‐sediment sequence recovered from the northeastern Nigerian Sahel and attempt to distinguish basin‐specific changes from regional climatic variations. The sequence was analysed for sedimentological properties, mineral magnetism and pollen, and dated by 137Cs, 210Pb excess and 14C. Extremely arid conditions of the terminal Pleistocene ended ca. 11 500 cal. BP (calendar years) when climate ameliorated and a lake developed until the occurrence of an arid event leading to lake desiccation at ~11 200 cal. BP. Following this, climate ameliorated and a water body re‐emerged. Very wet conditions predominated 11 200–5600 cal. BP, followed by drought between 5600 and 5500 cal. BP and a return to moderate humidity from 5500 to 4000 cal. BP. After 4000 cal. BP, a marked deterioration occurred, culminating in lake desiccation at ca. 800 cal. BP. After this time the climate remained generally dry and the re‐emerging lake was shallow. Comparison of these results with other well‐dated sequences in the region demonstrates the importance of basin‐specific influences on the palaeolimnological records in addition to regional climatic controls. Disentangling these different controls, as well as the reconstruction of Holocene climate, therefore requires a multiple‐basin approach. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
57.
One hundred thirty-four horizontally polarized shear-wave (SH) seismic soundings have been performed in the Jackson Purchase Region of western Kentucky. These data have been used to derive the thicknesses and shear-wave velocities for the various impedance horizons in the upper 30 m of the soil column at each site for the purposes of general land-use management and loss estimation in the event of an earthquake. A generalized seismic susceptibility soil classification scheme adopted by the Borcherdt (1994a,b) was fit to the results. Soils across western Kentucky were found to be either SC-II or SC-III soils, correlating to gravelly soils having soft to firm consistency and stiff clays to loose/dense sands, respectively. 相似文献
58.
59.
PENG Qiming Chinese Geological Survey Funei Street Xisi Beijing China M. R. PALMER Department of Geology University of Bristol Bristol BS RJ United Kingdom 《Continental Dynamics》1999,(1)
1.IntroductionFig.1. RegionalgeologyoftheeasternLiaoningSouthernJilinarea(AfterZhang,1984) ThePaleoproterozoicvolcanicsedimentarysequence,i.e.,theSouthLiaoheGroupandNorthLiaoheGroup,extendsbetweentwoArchaeancratons(Fig.1).Abundantmineralresources… 相似文献
60.
M. Dominik U.G. Jrgensen N.J. Rattenbury M. Mathiasen T.C. Hinse S. Calchi Novati K. Harpse V. Bozza T. Anguita M.J. Burgdorf K. Horne M. Hundertmark E. Kerins P. Kjrgaard C. Liebig L. Mancini G. Masi S. Rahvar D. Ricci G. Scarpetta C. Snodgrass J. Southworth R.A. Street J. Surdej C.C. Thne Y. Tsapras J. Wambsganss M. Zub 《Astronomische Nachrichten》2010,331(7):671-691
Within less than 15 years, the count of known planets orbiting stars other than the Sun has risen from none to more than 400 with detections arising from four successfully applied techniques: Doppler‐wobbles, planetary transits, gravitational microlensing, and direct imaging. While the hunt for twin Earths is on, a statistically well‐defined sample of the population of planets in all their variety is required for probing models of planet formation and orbital evolution so that the origin of planets that harbour life, like and including ours, can be understood. Given the different characteristics of the detection techniques, a complete picture can only arise from a combination of their respective results. Microlensing observations are well‐suited to reveal statistical properties of the population of planets orbiting stars in either the Galactic disk or bulge from microlensing observations, but a mandatory requirement is the adoption of strictly‐deterministic criteria for selecting targets and identifying signals. Here, we describe a fully‐deterministic strategy realised by means of the ARTEMiS (Automated Robotic Terrestrial Exoplanet Microlensing Search) system at the Danish 1.54‐m telescope at ESO La Silla between June and August 2008 as part of the MiNDSTEp (Microlensing Network for the Detection of Small Terrestrial Exoplanets) campaign, making use of immediate feedback on suspected anomalies recognized by the SIGNALMEN anomaly detector. We demonstrate for the first time the feasibility of such an approach, and thereby the readiness for studying planet populations down to Earth mass and even below, with ground‐based observations. While the quality of the real‐time photometry is a crucial factor on the efficiency of the campaign, an impairment of the target selection by data of bad quality can be successfully avoided. With a smaller slew time, smaller dead time, and higher through‐put, modern robotic telescopes could significantly outperform the 1.54‐m Danish, whereas lucky‐imaging cameras could set new standards for high‐precision follow‐up monitoring of microlensing events (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献