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91.
R. & R. Griffin 《Journal of Astrophysics and Astronomy》1990,11(3):281-290
HD 201270/1 is a composite-spectrum binary whose components have spectral types close to G8 III and A2 V. They are in a circular
orbit with a period of only 40 days. Photometric variability of RS CVn character is therefore not unlikely 相似文献
92.
HD 115781 and HD 116204 (BL CVn and BM CVn) are shown to be RS CVn binaries with periods near 20 days. HD 115781 is double-lined;
the primary type is about K1III, while the secondary is probably a late-type subgiant. The masses of the two components are equal within observational error.
There is substantial photometric variability with a period half the orbital period; it is attributed to ellipsoidal variation.
HD 116204 is also of type K1III. It shows exceptionally strong Ca II H and K emission, together with an emission-line spectrum typical of RS CVn stars in
theIUE ultraviolet region, but Hα is an absorption line. The secondary star in the HD 116204 system has not been detected. The primary
shows photometric variations, presumably due to starspots, with a period 5 per cent longer than the orbital period. 相似文献
93.
Ian Halliday Alan T. Blackwell Arthur A. Griffin 《Meteoritics & planetary science》1989,24(3):173-178
Abstract— We derive values for the number and size distributions of meteorites landing on Earth from a study of photographic observations of bright fireballs with the Canadian camera network. The observations cover 11 years from 1974 to 1985. This analysis is an extension of a previous study and represents a 30% increase in the data base. The cumulative plot of numbers vs estimated mass of the largest fragment for each event shows a change in slope near 0.6 kg due to a deficiency of small meteorites surviving from the group of slow fireballs. The change can be explained by a mass dependence of the fraction of the incoming object that survives as the largest fragment. For larger falls, the main mass appears to represent a decreasing fraction of the total mass of the surviving meteorites and estimates of these effects are used to derive the final distribution of both main masses and total masses of meteoritic events. For total masses greater than 1 kg the population index is 1.82, close to previous estimates. About 9 events per year drop at least 1 kg of meteorites in an area of a million square km and the same area receives an annual influx of 54 kg from meteorite events with total masses between 0.01 and 100 kg. There is sufficient confidence in these results that they may be used for comparison of the present flux of meteorites with values inferred for other times, in particular the long accumulation times of the Antarctic meteorite collections. 相似文献
94.
R. F. Griffin 《Journal of Astrophysics and Astronomy》1982,3(4):383-392
Photoelectric radial-velocity measurements have confirmed O. C. Wilson’s finding that BD 33° 2206, the secondary star in the
wide visual binary ADS 8470, is a spectroscopic binary. It has an eccentric orbit with a period of 100 days. Its γ-velocity
is close to the constant radial velocity of the visual primary, confirming the physical association of the stars. 相似文献
95.
Topographic shading curtails the period and complicates the geographic patterns of insolation in mountainous areas. Maps derived from oblique aerial photographs of shadow lines cast by the irregular, mountainous east horizon in Provo, Utah are used as a case study to illustrate an alternative to existing techniques of solar radiation data collection. For study areas of several hundred square kilometers, this method may be superior in resolution and at the same time more error free and economically feasible than other methods. Measurement of solar inputs received at sample stations scattered through the mapped area show that the phenomenon of topographically delayed sunrise has a distinct effect on daily totals of radiation in the manner suggested by the maps. 相似文献
96.
Dale Andrew 《Marine Policy》1978,2(1):46-64
At first sight, the regime suggested for archipelagos at UNCLOS seems to recognize to a large extent the concept of the archipelago as a single unit of islands and water. The author examines closely whether in fact the archipelagic states' view of their maritime jurisdiction has been upheld, or whether the negotiations have led to a position based on traditional concepts of law of the sea. The archipelago doctrine and interests underlying it, opposition to it, and the considerations by the international legal community are discussed. Finally, developments on archipelagos in the Seabed Committee and UNCLOS III are traced in order to understand the language of the proposed archipelagic regime. 相似文献
97.
J.?A.?HalpinEmail author C.?L.?Gerakiteys G.?L.?Clarke E.?A.?Belousova W.?L.?Griffin 《Contributions to Mineralogy and Petrology》2005,148(6):689-706
In-situ zircon U–Pb and Hf isotopic analysis via laser ablation microprobe-inductively coupled plasma mass spectrometer (LAM-ICPMS) of samples from Kemp and MacRobertson Lands, east Antarctica suggests that the Kemp Land terrane evolved separately from the rest of the Rayner Complex prior to the ca. 940 Ma Rayner Structural Episode. Several Archaean metamorphic events in rocks from western Kemp Land can be correlated with events previously reported for the adjacent Napier Complex. Recently reported ca. 1,600 Ma isotopic disturbance in rocks from the Oygarden Group may be correlated with a charnockitic intrusion in the Stillwell Hills before ca. 1,550 Ma. Despite being separated by some 200 km, THfDM ages indicate felsic orthogneiss from Rippon Point, the Oygarden Group, Havstein Island and the Stillwell Hills share a ca. 3,660–3,560 Ma source that is indistinguishable from that previously reported for parts of the Napier Complex. More recent additions to this crust include Proterozoic charnockite in the Stillwell Hills and the vicinity of Mawson Station. These plutons have distinct 176Hf/177Hf ratios and formed via the melting of crust generated at ca. 2,150–2,550 Ma and ca. 1,790–1,870 Ma respectively. 相似文献
98.
New spectra of Jupiter in the region 0.93–1.63 are presented. Laboratory comparisons of spectra of NH3 and CH4 permit estimates of the absorbing pathlength for various bands of these two gases. Abundances in a single transmission through the Jupiter atmosphere, above the mean reflecting level, vary from 10 to 100 m-atm for CH4 and from 0.2–5 m-atm for NH3, depending on the bands considered. Upper limits for other gases are derived from new laboratory spectra and comparison with the Jupiter spectra presented herein. These are as follows: C2H2<2 m-atm, H2S<0.25 m-atm, HCN<0.05 m-atm, CH3NH2<0.02 m-atm. A table summarizing the chemical composition of Jupiter's atmosphere is presented. 相似文献
99.
100.
Infrared spectrophotometric measurements of Neptune's satellite Triton obtained between 1980 and 1982 in the spectral range 0.8–2.5 μm show six individual absorption bands attributable to methane. An additional band in the Triton data is not methane. The Triton spectral data conform more closely to a laboratory spectrum of frozen methane than to a synthetic spectrum of methane gas computed for conditions of low temperature expected at the satellite. Additionally, the strength of the bands vary with Triton's orbital position. The data thus suggest that methane in the ice phase is mostly responsible for the bands in Triton's spectrum, and that the ice is distributed nonuniformly around the satellite's surface. 相似文献