全文获取类型
收费全文 | 73篇 |
免费 | 0篇 |
专业分类
大气科学 | 1篇 |
地球物理 | 10篇 |
地质学 | 26篇 |
海洋学 | 8篇 |
天文学 | 27篇 |
自然地理 | 1篇 |
出版年
2023年 | 1篇 |
2022年 | 2篇 |
2021年 | 2篇 |
2020年 | 2篇 |
2018年 | 1篇 |
2017年 | 6篇 |
2016年 | 4篇 |
2014年 | 3篇 |
2013年 | 2篇 |
2012年 | 4篇 |
2011年 | 1篇 |
2010年 | 4篇 |
2009年 | 3篇 |
2008年 | 10篇 |
2007年 | 2篇 |
2006年 | 4篇 |
2004年 | 2篇 |
2003年 | 1篇 |
2001年 | 3篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1987年 | 2篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1980年 | 1篇 |
1975年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有73条查询结果,搜索用时 0 毫秒
31.
The simultaneous high resolution recordings of dynamic spectra in the range 93–220 MHz and polarization at 204 MHz of a complex type II–IV event which started at 08:33 UT on 3 May 1973 shown a sporadic zebra pattern. In contrast with the unpolarized type II burst, the stripes in the emission and absorption of the zebra pattern were fully polarized and most likely corresponded to the ordinary wave. As to spectral and polarization characteristics, the fiber bursts with intermediate frequency drift did not differ from the stripes of the zebra pattern. The microstructure of the type II burst was characterised by a lot of spikes with variable frequency drift, duration 0.1 s and instantaneous bandwidth ≈1 MHz. 相似文献
32.
Analyzing a fiber burst occurring in the event on 19 August, 1981, plasma parameters of the burst source volume are estimated by means of Kuijpers' (1975) fiber burst model. The derived height dependence of the density in a coronal loop agrees with an isothermal barometric loop atmosphere. 相似文献
33.
34.
35.
36.
37.
Doklady Earth Sciences - 相似文献
38.
Gennady P.Chernov 《中国天文和天体物理学报》2010,10(9)
This review covers the most recent experimental results and theoretical research on zebra patterns(ZPs)in solar radio bursts.The basic attention is given to events with new peculiar elements of zebra patterns received over the last few years.All new properties are considered in light of both what was known earlier and new theoretical models.Large-scale ZPs consisting of small-scale fiber bursts could be explained by simultaneous inclusion of two mechanisms when whistler waves"highlight"the levels of double plasma resonance(DPR).A unique fine structure was observed in the event on 2006 December 13: spikes in absorption formed dark ZP stripes against the absorptive type Ⅲ-like bursts.The spikes in absorption can appear in accordance with well known mechanisms of absorptive bursts.The additional injection of fast particles filled the loss-cone(breaking the loss-cone distribution),and the generation of the continuum was quenched at these moments.The maximum absorptive effect occurs at the DPR levels.The parameters of millisecond spikes are determined by small dimensions of the particle beams and local scale heights in the radio source.Thus,the DPR model helps to understand several aspects of unusual elements of ZPs.However,the simultaneous existence of several tens of the DPR levels in the corona is impossible for any realistic profile of the plasma density and magnetic field.Three new theories of ZPs are examined.The formation of eigenmodes of transparency and opacity during the propagation of radio waves through regular coronal inhomogeneities is the most natural and promising mechanism.Two other models(nonlinear periodic space-charge waves and scattering of fast protons on ion-sound harmonics)could happen in large radio bursts. 相似文献
39.
When analyzing YOHKOH/SXT, HXT (soft and hard X-ray) images of solar flares against the background of plasma with a temperature T?6 MK, we detected localized (with minimum observed sizes of ≈2000 km) high-temperature structures (HTSs) with T≈(20–50) MK with a complex spatial-temporal dynamics. Quasi-stationary, stable HTSs form a chain of hot cores that encircles the flare region and coincides with the magnetic loop. No structures are seen in the emission measure. We reached conclusions about the reduced heat conductivity (a factor of ~103 lower than the classical isotropic one) and high thermal insulation of HTSs. The flare plasma becomes collisionless in the hottest HTSs (T>20 MK). We confirm the previously investigated idea of spatial heat localization in the solar atmosphere in the form of HTSs during flare heating with a volume nonlocalized source. Based on localized soliton solutions of a nonlinear heat conduction equation with a generalized flare-heating source of a potential form including radiative cooling, we discuss the nature of HTSs. 相似文献
40.
The variation of intensity in spectral line wings, which was obtained from observations of the patrol telescope at the Kislovodsk Mountain Astronomical Station of the Pulkovo Observatory, Russian Academy of Science (KMAS) and the Interface Region Imaging Spectrograph (IRIS) space observatory, are considered. A series of observations lasting a few hours near the solar active regions, in which both short- and longperiod oscillations were observed simultaneously during 2014–2015, are analyzed. It is found out that oscillations with a period of 3–5 min can exist at one time and in one place with oscillations with a period of about 100 min. The amplitude of long-period oscillations can be comparable with that for short-period oscillations. The conditions for excitation of the wave processes are considered. Oscillations with a period of 100 min have a weak dependence on the area of the active region. 相似文献