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排序方式: 共有224条查询结果,搜索用时 31 毫秒
81.
J. E. J. Lovell H. Hirabayashi H. Kobayashi Y. Murata P. G. Edwards G. A. Moellenbrock S. Horiuchi E. B. Fomalont S. Kameno K. M. Shibata 《New Astronomy Reviews》1999,43(8-10)
An overview and status report of the VLBI Space Observatory Programme is presented. 相似文献
82.
83.
Gradients of absorption line indices are studied and mean stellar metallicities are estimated for 46 elliptical galaxies.
The mean stellar metallicities range from 〈 [Fe/H] 〉 ≃ =0.8 to +0.2 and ellipticals with smaller central velocity dispersions
tend to have lower 〈 [Fe/H] 〉 thus the mass-metallicity relation holds not only for the galaxy center but also for the whole
part of the galaxy. There is an evidence that the magnesium is enhanced systematically in all ellipticals by 0.2 dex with
respect to the iron. Giant elliptical galaxies show lack of metal-poor stars (the G-dwarf problem). Metal-poor globular clusters
of ellipticals formed well in advance of the formation of metal-rich ones which formed simultaneously with the bulk of stars
of mother galaxies under the influence of galaxy chemical enrichment. The bimodal [Fe/H] distribution of globular clusters
does not necessarily mean that elliptical galaxies formed by the mergers of disc galaxies.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
84.
85.
G. Giono R. Ishikawa N. Narukage R. Kano Y. Katsukawa M. Kubo S. Ishikawa T. Bando H. Hara Y. Suematsu A. Winebarger K. Kobayashi F. Auchère J. Trujillo Bueno S. Tsuneta T. Shimizu T. Sakao J. Cirtain P. Champey A. Asensio Ramos J. Štěpán L. Belluzzi R. Manso Sainz B. De Pontieu K. Ichimoto M. Carlsson R. Casini M. Goto 《Solar physics》2017,292(4):57
The Chromospheric Lyman-Alpha SpectroPolarimeter is a sounding rocket instrument designed to measure for the first time the linear polarization of the hydrogen Lyman-\({\upalpha }\) line (121.6 nm). The instrument was successfully launched on 3 September 2015 and observations were conducted at the solar disc center and close to the limb during the five-minutes flight. In this article, the disc center observations are used to provide an in-flight calibration of the instrument spurious polarization. The derived in-flight spurious polarization is consistent with the spurious polarization levels determined during the pre-flight calibration and a statistical analysis of the polarization fluctuations from solar origin is conducted to ensure a 0.014% precision on the spurious polarization. The combination of the pre-flight and the in-flight polarization calibrations provides a complete picture of the instrument response matrix, and a proper error transfer method is used to confirm the achieved polarization accuracy. As a result, the unprecedented 0.1% polarization accuracy of the instrument in the vacuum ultraviolet is ensured by the polarization calibration. 相似文献
86.
Cyanobacteria attracted much attention recently because of their secondary metabolites with potent biological activities and unusual structures. This paper reviews some recent studies on the isolation, structural, elucidation and biological activities of the bioactive compounds from cyanobacteriaNostoc species.
相似文献87.
A continuous observation system of ship drift of ferry boats was developed using Loran C, ship direction, ship speed and wind velocity measurement. A formula to estimate the wind-driven lateral drift of the boat is proposed, and a measuring system of the surface current is described, including a discussions on its usefullness to monitor day-to-day variations of the circulation patterns in the coastal boundary regions of the Kuroshio.This system was applied to observe variations of the circulation in the Kumano-nada, and Enshu-nada Seas south of Japan. Some preliminary results were obtained by using this system as well as other methods. This work focuses on the behavior of warm eddies in the Kumano-nada Sea. The surface current patterns that include these phenomena obtained by the use of the ship drift show good correspondence with currents and thermal structures observed with GEK, CTD, moored current meters and satellite thermal images. 相似文献
88.
Naoto Iwasaka Toshio Suga Kensuke Takeuchi Keisuke Mizuno Yasushi Takatsuki Kentaro Ando Taiyo Kobayashi Eitarou Oka Yasuko Ichikawa Motoki Miyazaki Hiroshi Matsuura Kenji Izawa Chan-Su Yang Nobuyuki Shikama Momoko Aoshima 《Journal of Oceanography》2003,59(1):119-127
We deployed two profiling floats in the region south of the Kuroshio Extension in March 2000. Temperature and salinity profiles
from a depth of 1500 × 104 Pa to the surface are reported every two and four weeks, respectively. The floats performed very well for first four months
after deployment. Later they failed in surfacing for a few months when the sea surface temperature in the region was high.
The salinity sensors seemed to suffer from some damage during their failure-in-surfacing period. Despite this trouble, the
results clearly demonstrate that the profiling float is a very useful and cost-effective tool for physical oceanographic observation
in the open sea.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
89.
90.
Tsutomu Ota Katsura Kobayashi Tomoo Katsura Eizo Nakamura 《Contributions to Mineralogy and Petrology》2008,155(1):19-32
Pressure–temperature conditions of tourmaline breakdown in a metapelite were determined by high-pressure experiments at 700–900°C
and 4–6 GPa. These experiments produced an eclogite–facies assemblage of garnet, clinopyroxene, phengite, coesite, kyanite
and rare rutile. The modal proportions of tourmaline clearly decreased between 4.5 and 5 GPa at 700°C, between 4 and 4.5 GPa
at 800°C, and between 800 and 850°C at 4 GPa, with tourmaline that survived the higher temperature conditions appearing corroded
and thus metastable. Decreases in the modal abundance of tourmaline are accompanied by decreasing modal abundance of coesite,
and increasing that of clinopyroxene, garnet and kyanite; the boron content of phengite increases significantly. These changes
suggest that, with increasing pressure and temperature, tourmaline reacts with coesite to produce clinopyroxene, garnet, kyanite,
and boron-bearing phengite and fluid. Our results suggest that: (1) tourmaline breakdown occurs at lower pressures and temperatures
in SiO2-saturated systems than in SiO2-undersaturated systems. (2) In even cold subduction zones, subducting sediments should release boron-rich fluids by tourmaline
breakdown before reaching depths of 150 km, and (3) even after tourmaline breakdown, a significant amount of boron partitioned
into phengite could be stored in deeply subducted sediments. 相似文献