全文获取类型
收费全文 | 412篇 |
免费 | 17篇 |
国内免费 | 6篇 |
专业分类
测绘学 | 8篇 |
大气科学 | 30篇 |
地球物理 | 132篇 |
地质学 | 109篇 |
海洋学 | 53篇 |
天文学 | 62篇 |
综合类 | 4篇 |
自然地理 | 37篇 |
出版年
2023年 | 2篇 |
2021年 | 5篇 |
2020年 | 6篇 |
2019年 | 7篇 |
2018年 | 11篇 |
2017年 | 8篇 |
2016年 | 18篇 |
2014年 | 9篇 |
2013年 | 13篇 |
2012年 | 9篇 |
2011年 | 25篇 |
2010年 | 8篇 |
2009年 | 19篇 |
2008年 | 27篇 |
2007年 | 25篇 |
2006年 | 29篇 |
2005年 | 19篇 |
2004年 | 24篇 |
2003年 | 13篇 |
2002年 | 13篇 |
2001年 | 5篇 |
2000年 | 14篇 |
1999年 | 5篇 |
1998年 | 10篇 |
1997年 | 5篇 |
1995年 | 8篇 |
1994年 | 4篇 |
1993年 | 8篇 |
1992年 | 4篇 |
1991年 | 5篇 |
1990年 | 6篇 |
1989年 | 9篇 |
1988年 | 8篇 |
1987年 | 2篇 |
1986年 | 6篇 |
1985年 | 5篇 |
1984年 | 8篇 |
1983年 | 2篇 |
1982年 | 4篇 |
1981年 | 4篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 5篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1971年 | 2篇 |
1970年 | 1篇 |
1969年 | 1篇 |
1968年 | 1篇 |
1967年 | 2篇 |
排序方式: 共有435条查询结果,搜索用时 15 毫秒
281.
S. Noda M. Takeuti F. Abe I. A. Bond R. J. Dodd J. B. Hearnshaw M. Honda M. Honma J. Jugaku Y. Kan-ya Y. Kato P. M. Kilmartin Y. Matsubara K. Masuda Y. Muraki T. Nakamura K. Ohnishi M. Reid N. J. Rattenbury To. Saito Y. Saito H. Sato M. Sekiguchi J. Skuljan D. J. Sullivan T. Sumi R. Yamada T. Yanagisawa P. C. M. Yock M. Yoshizawa 《Monthly notices of the Royal Astronomical Society》2004,348(4):1120-1134
282.
1 IntroductionAlongwiththearrivalof2 3rdsolaractivepeakandthedevelopmentofthespacesci ence ,thescientistsaremoreandmoreinterestedintopicsofgeospaceeffectscausedbytheintensesolaractivities.Thegeospaceeffectsofseveralextremesolaractiveevents,suchasthe 1 993No… 相似文献
283.
284.
285.
Shigehiro Nagataki Kazunori Kohri Shinichiro Ando Katsuhiko Sato 《Astroparticle Physics》2003,18(6):551-564
We estimate the flux of the gamma-ray burst (GRB) neutrino background and compute the event rate at SK and TITAND in the collapsar model, assuming that GRB formation rate is proportional to the star formation rate. We find that the predicted background neutrino flux is highly sensitive to unknown model parameters, mainly to the mass–accretion rate, to the fraction of disk energy emitted in thermal neutrinos (as opposed to emission through electromagnetic processes), and to the fraction of collapsar events leading to GRBs. The predicted neutrino flux varies over many orders of magnitude as the values of unknown model parameters are varied. We investigate the detection possibility of thermal neutrinos from collapsars which lead to GRBs by TITAND. We find that the GRB neutrino background might be detected by TITAND within 10 yrs only for the optimistic cases in which the average mass–accretion rate is high ( a few M s−1), and the probability that one collapsar generates a GRB is high (f=0.5–1.0). 相似文献
286.
Reiko Furusho Yuji Ikeda Wing-Huen Ip Toshihiro Kasuga Yusuke Sato Ming-Shin Chang Jun-ichi Watanabe 《Icarus》2007,190(2):454-458
The NASA's Deep Impact mission was the first impact experiment to a cometary nucleus. The target of the mission was Comet 9P/Tempel, one of the Jupiter family comets. The impact was performed on July 4th, 2005. Imaging polarimetric observations were carried out by Polarimetric Imager for COmets (PICO) mounted on the Lulin One-meter Telescope (LOT) at Lulin Observatory, Taiwan. Intensity and linear polarization degree maps were obtained on July 3-5, 2005. Impact ejecta plume was clearly recognized in the enhanced intensity map. Furthermore, arc-shaped region of high polarization was recognized in the polarization map. Dust grains in this region had larger expansion velocity than the grains which provided the brightest area in the intensity map. comparing our results with the MIR spectroscopy obtained by Subaru Telescope we conclude that very small carbonaceous grains might be responsible for the region of high polarization. 相似文献
287.
Yoshinobu Sato Xieyao Ma Jianqing Xu Masayuki Matsuoka Hongxing Zheng Changming Liu Yoshihiro Fukushima 《水文研究》2008,22(11):1618-1629
To analyse the long‐term water balance of the Yellow River basin, a new hydrological model was developed and applied to the source area of the basin. The analysis involved 41 years (1960–2000) of daily observation data from 16 meteorological stations. The model is composed of the following three sub‐models: a heat balance model, a runoff formation model and a river‐routing network model. To understand the heat and water balances more precisely, the original model was modified as follows. First, the land surface was classified into five types (bare, grassland, forest, irrigation area and water surface) using a high‐resolution land‐use map. Potential evaporation was then calculated using land‐surface temperatures estimated by the heat balance model. The maximum evapotranspiration of each land surface was calculated from potential evaporation using functions of the leaf area index (LAI). Finally, actual evapotranspiration was estimated by regulating the maximum evapotranspiration using functions of soil moisture content. The river discharge estimated by the model agreed well with the observed data in most years. However, relatively large errors, which may have been caused by the overestimation of surface flow, appeared in some summer periods. The rapid decrease of river discharge in recent years in the source area of the Yellow River basin depended primarily on the decrease in precipitation. Furthermore, the results suggested that the long‐term water balance in the source area of the Yellow River basin is influenced by land‐use changes. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
288.
The diffuse soft X-ray background in 0.07∼ 2.0 keV has been observed along a small circle with the angular width of 10– covering
b=—57– ∼ 77– and crossing the galactic plane at l=125– and 283–. Observed spectra are well fitted with models emitted from a thin hot gas with two or multi-temperature components
and attenuated by a slab or interspersed neutral gas clouds. However the multi-temperature component model has some difficulties
to explain the diffuse component expected from observations of OVI absorption lines. The two temperature component model with
interspersed clouds consistently interprets a physical state of the hot interstellar medium. It turned out that the hot interstellar
medium interspersed with neutral clouds of a representative hydrogen column density of 1× 1020 cm-2has two temperature components (105.8 K,(1.2-4.5)× 106 K) and a disk-like distribution with the thickness of 580(± 100). {(p/k)/104cm-3 K} -2 pc at the pressure of p/k cm-3 K along the galactic plane. Its pressure (p/k) is obtained to be 1.4(+0.7,-0.5)× 104cm-3 K, assuming that hot gases responsible for the diffuse soft X-rays and OVI ions are in pressure equilibrium. This interpretation
qualitatively agrees with the theoretical prediction proposed by McKee and Ostriker.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
289.
290.
CO(2) ocean storage by which liquefied CO(2) is injected into the deep-sea to mitigate the climate change would increase the CO(2) concentrations of the surrounding seawater. The biological impacts of such dynamic CO(2) environments are, however, unknown. We examined the acute toxicity of temporally changing seawater CO(2) concentrations on juveniles of Sillago japonica. Step-wise increases in ambient CO(2) to fCO(2) (fractional CO(2) concentration of the gas mixture bubbled into seawater) levels of 7% and 9% resulted in mortalities of 0.15 and 0.40-0.67 after 18 h, respectively. In contrast, one-step increases to these CO(2) levels killed all fish within 15 min. Further, a sudden drop of fCO(2) from 9-10% CO(2) to normocapnia (0.038%) killed all the surviving fish within a few minutes. These results demonstrate that impacts of ocean CO(2) storage need to be examined under conditions mimicking the dynamic changes in CO(2) levels expected to occur by the CO(2) injection procedure. 相似文献