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211.
The Assessment of Global Surface Temperature Change from 1850s:The C-LSAT2.0 Ensemble and the CMST-Interim Datasets 总被引:1,自引:0,他引:1
Wenbin SUN Qingxiang LI Boyin HUANG Jiayi CHENG Zhaoyang SONG Haiyan LI Wenjie DONG Panmao ZHAI Phil JONES 《大气科学进展》2021,38(5):875-888
Based on C-LSAT2.0,using high-and low-frequency components reconstruction methods,combined with observation constraint masking,a reconstructed C-LSAT2.0 with 756 ensemble members from the 1850s to 2018 has been developed.These ensemble versions have been merged with the ERSSTv5 ensemble dataset,and an upgraded version of the CMSTInterim dataset with 5°×5°resolution has been developed.The CMST-Interim dataset has significantly improved the coverage rate of global surface temperature data.After reconstruction,the data coverage before 1950 increased from 78%?81%of the original CMST to 81%?89%.The total coverage after 1955 reached about 93%,including more than 98%in the Northern Hemisphere and 81%?89%in the Southern Hemisphere.Through the reconstruction ensemble experiments with different parameters,a good basis is provided for more systematic uncertainty assessment of C-LSAT2.0 and CMSTInterim.In comparison with the original CMST,the global mean surface temperatures are estimated to be cooler in the second half of 19th century and warmer during the 21st century,which shows that the global warming trend is further amplified.The global warming trends are updated from 0.085±0.004℃(10 yr)–1and 0.128±0.006℃(10 yr)–1to 0.089±0.004℃(10 yr)–1and 0.137±0.007℃(10 yr)–1,respectively,since the start and the second half of 20th century. 相似文献
212.
Dane Quinn Brett Gladman Phil Nicholson Richard Rand 《Celestial Mechanics and Dynamical Astronomy》1997,67(2):111-130
We study the rotational evolution under tidal torques of axisymmetric natural satellites in inclined, precessing orbits. In
the spin- and orbit-averaged equations of motion, we find that a global limit cycle exists for parameter values near the stability
limit of Cassini state
. The limit cycle involves an alternation between states of near-synchronous spin at low obliquity, and strongly subsynchronous
spin at an obliquity near 90°. This dynamical feature is characterized as a relaxation oscillation, arising as the system
slowly traverses two saddle-node bifurcations in a reduced system. This slow timescale is controlled by ε, the nondimensional
tidal dissipation rate. Unfortunately, a straightforward expansion of the governing equations for small ε is shown to be insufficient
for understanding the underlying structure of the system. Rather, the dynamical equations of motion possess a singular term,
multiplied by ε, which vanishes in the unperturbed system. We thus provide a demonstration that a dissipatively perturbed
conservative system can behave qualitatively differently from the unperturbed system.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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The large-scale solar velocity field has been measured over an aperture of radius 0.8 R
on 121 days between April and September, 1976. Measurements are made in the line Fei 5123.730 Å, employing a velocity subtraction technique similar to that of Severny et al. (1976). Comparisons of the amplitude and frequency of the five-minute resonant oscillation with the geomagnetic C9 index and magnetic sector boundaries show no evidence of any relationship between the oscillations and coronal holes or sector structure. 相似文献
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219.
Phil Hubbard 《Area》1999,31(3):229-237
Summary Against the backdrop of ongoing debates about the nature of 'critical' geography, this paper considers the importance of intensive, action-oriented and conversational research methodologies in providing a 'Voice' to excluded populations. The distinct contribution of such methods to the understanding of exclusion is illustrated with reference to research on female prostitution, drawing on the author's own experiences as well as those of feminist researchers in health and the social sciences. However, the paper concludes by comparing the emancipatory potential of such qualitative methods with more quantitative approaches, arguing that no one method can be prioritized in the search for 'useful' know. 相似文献
220.
Toshitaka Baba Phil R. Cummins Hong Kie Thio Hiroaki Tsushima 《Pure and Applied Geophysics》2009,166(1-2):55-76
The importance of accurate tsunami simulation has increased since the 2004 Sumatra-Andaman earthquake and the Indian Ocean tsunami that followed it, because it is an important tool for inundation mapping and, potentially, tsunami warning. An important source of uncertainty in tsunami simulations is the source model, which is often estimated from some combination of seismic, geodetic or geological data. A magnitude 8.3 earthquake that occurred in the Kuril subduction zone on 15 November, 2006 resulted in the first teletsunami to be widely recorded by bottom pressure recorders deployed in the northern Pacific Ocean. Because these recordings were unaffected by shallow complicated bathymetry near the coast, this provides a unique opportunity to investigate whether seismic rupture models can be inferred from teleseismic waves with sufficient accuracy to be used to forecast teletsunami. In this study, we estimated the rupture model of the 2006 Kuril earthquake by inverting the teleseimic waves and used that to model the tsunami source. The tsunami propagation was then calculated by solving the linear long-wave equations. We found that the simulated 2006 Kuril tsunami compared very well to the ocean bottom recordings when simultaneously using P and long-period surface waves in the earthquake source process inversion. 相似文献