全文获取类型
收费全文 | 78篇 |
免费 | 5篇 |
国内免费 | 5篇 |
专业分类
测绘学 | 4篇 |
大气科学 | 10篇 |
地球物理 | 18篇 |
地质学 | 26篇 |
海洋学 | 9篇 |
天文学 | 16篇 |
自然地理 | 5篇 |
出版年
2023年 | 1篇 |
2022年 | 2篇 |
2021年 | 4篇 |
2020年 | 2篇 |
2019年 | 3篇 |
2018年 | 2篇 |
2017年 | 5篇 |
2016年 | 4篇 |
2015年 | 4篇 |
2014年 | 3篇 |
2013年 | 4篇 |
2012年 | 2篇 |
2011年 | 6篇 |
2010年 | 8篇 |
2009年 | 2篇 |
2008年 | 4篇 |
2007年 | 4篇 |
2006年 | 2篇 |
2005年 | 3篇 |
2004年 | 2篇 |
2002年 | 1篇 |
2001年 | 3篇 |
1999年 | 1篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1993年 | 1篇 |
1991年 | 1篇 |
1985年 | 1篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1974年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有88条查询结果,搜索用时 234 毫秒
61.
Makitov V. S. Inuhin V. S. Kushchev S. A. Liev K. B. 《Izvestiya Atmospheric and Oceanic Physics》2022,58(4):384-390
Izvestiya, Atmospheric and Oceanic Physics - The results of long-term continuous radar observations of a multicellular hail system that developed over the central part of the North Caucasus June 7,... 相似文献
62.
63.
Kuksenko Viktor 《地震学报(英文版)》2011,(3):283-298
The experimental results of 3-D fracture under compression are introduced in brief and the theory of stress criterion of 3-D fracture is studied.Methods to imitate initial fractures are developed.It is pointed that there are important defects in the extreme value(EV)method ever proposed by Palaniswamy and Knauss. The major defect lies in that only two Euler angles(2EA)are considered,but another one is neglected.If the variation of all the three Euler angles(3EA)are considered,one can get better result wh... 相似文献
64.
Multispectral polarimetry as a tool to investigate texture and chemistry of lunar regolith particles
Yuriy Shkuratov Nikolay Opanasenko Yevgen Grynko Viktor Korokhin Gorden Videen Urs Mall 《Icarus》2007,187(2):406-416
We report results of telescope polarimetric imaging of the Moon with a CCD LineScan Camera at large phase angles, near 88°. This allows measurements of the polarization degree with an absolute accuracy better than 0.3% and detection of features with polarization contrast as small as 0.1%. The measurements are carried out in two spectral bands centered near 0.65 and 0.42 μm. We suggest characterizing the lunar regolith with the parameter a(Pmax)A, where Pmax,A, and a are the degree of maximum polarization, albedo, and the parameter describing the linear regression of the correlation Pmax-A. The parameter bears significant information on the particle characteristic size and packing density of the lunar regolith. We also suggest characterizing the lunar regolith with color-ratio images obtained with a polarization filter at large phase angles. We here consider the color-ratios C||(0.65/0.42 μm) and C⊥(0.65/0.42 μm). Using light scattering model calculations we show that the color-ratio images obtained with a polarization filter at large phase angles suggest a new tool to study the lunar surface. In particular, it turns out that the color-ratios C||(0.65/0.42 μm) and C⊥(0.65/0.42 μm) are sensitive to somewhat different thicknesses of the surfaces of regolith particles. We consider the applicability of the Hubble Space Telescope, the Very Large Telescope (ESO), and a spacecraft on a lunar polar orbit for polarimetric observations of the lunar surface. 相似文献
65.
66.
The direct propagation of acoustic waves, driven harmonically at the solar photosphere, into the three-dimensional solar atmosphere
is examined numerically in the framework of ideal magnetohydrodynamics. It is of particular interest to study the leakage
of 5-minute global solar acoustic oscillations into the upper, gravitationally stratified and magnetised atmosphere, where
the modelled solar atmosphere possesses realistic temperature and density stratification. This work aims to complement and
bring further into the 3D domain our previous efforts (by Erdélyi et al., 2007, Astron. Astrophys. 467, 1299) on the leakage of photospheric motions and running magnetic-field-aligned waves excited by these global oscillations.
The constructed model atmosphere, most suitable perhaps for quiet Sun regions, is a VAL IIIC derivative in which a uniform
magnetic field is embedded. The response of the atmosphere to a range of periodic velocity drivers is numerically investigated
in the hydrodynamic and magnetohydrodynamic approximations. Among others the following results are discussed in detail: i) High-frequency waves are shown to propagate from the lower atmosphere across the transition region, experiencing relatively
low reflection, and transmitting most of their energy into the corona; ii) the thin transition region becomes a wave guide for horizontally propagating surface waves for a wide range of driver periods,
and particularly at those periods that support chromospheric standing waves; iii) the magnetic field acts as a waveguide for both high- and low-frequency waves originating from the photosphere and propagating
through the transition region into the solar corona.
Electronic Supplementary Material The online version of this article () contains supplementary material, which is available to authorized users. 相似文献
67.
Abstract— Yamato 000593, a nakhlite, was analyzed in terms of its magnetic record and magnetomineralogy. The natural remanent magnetization (NRM: 3.55–6.07 times 10?5 Am2/kg) was thermally demagnetized at ~320 °C, and it was unstable against alternating field demagnetization. Based on analyses of thermomagnetic curves, the temperature dependence of hysteresis parameters, and microscopic observations, the magnetic minerals mainly consist of magnetite (0.68 wt% of the sample, including ~5% Fe2TiO4) of less than 100 μm in size, associated with minor amounts of monoclinic pyrrhotite (<0.069 wt% of the sample) and goethite. Thermal demagnetization of NRM at ~330 °C is explained due to an offset of magnetization of antipodal NRM components of magnetite, whereas it is not due to a pyrrhotite Curie point. Large magnetite grains show exsolution texture with ilmenite laths, and are cut by silicate (including goethite) veins that formed along cracks. Numerous single‐domain (SD) and pseudo‐single‐domain (PSD) magnetite grains are scattered in the mesostasis and adjacent olivine grains. Moderate coercive forces of HC = 6.8 mT and HRC = 31.1 mT suggest that Yamato 000593 is fundamentally able to carry a stable NRM; however, NRM was found to be unstable. Accordingly, the meteorite was possibly crystallized at 1.3 Ga under an extremely weak or absent magnetic field, or was demagnetized by impact shock at 12 Ma (ejection age) on Mars. This finding differs from the results of previous paleomagnetic studies of SNC (shergottites, nakhlites, chassignites, and orthopyroxenite) Martian meteorites. The significant dipole magnetic field resulting from the molten metallic core was probably absent during the Amazonian Epoch (after 1.8 Ga) on Mars. 相似文献
68.
The results of the analysis of long-term radar research of the hailstorms over the central part of the Northern Caucasus are presented. Radar observations which formed the basis of experimental material were carried out continuously from the moment of the first radar echo registration until complete dissipation of the hailstorm. The computerized system of collecting, processing and the analysis of the radar information was used. Time discretization of the radar parameters of the full spatial observation averaged 3 min. Statistical sampling of radar data included 392 hail cells, for each of which the time distributions of the radar parameters both measured and calculated using the computerized system were compiled. Distribution of the hailstorms first radar echo formation zones over the observation region was compiled. Areas with the maximum frequency of the hailstorms first radar echo formation were defined. The hailstorm trajectories were analyzed. Four main types of hail cell trajectories were selected, which included 86 % of the supercells and 64 % of the long-lived multicells. The dynamic parameters of the hail core formation and development were analyzed. The hail storm characteristics of the Northern Caucasus are compared to the hail storms of Mendoza, Argentina, and Alberta, Canada. The bases of the organization of regional hail suppression services which use the rocket technology of cloud seeding are presented. The results of the cloud seeding operations during recent years are shown. 相似文献
69.
70.
Patrice de Caritat Clemens Reimann Matti Äyräs Heikki Niskavaara Viktor A. Chekushin Vladimir A. Pavlov 《Aquatic Geochemistry》1996,2(2):169-184
Stream water composition, measured weekly for 8–9 months in 1994 in three arctic catchments on and around the Kola Peninsula (Russia, Finland and Norway), is presented in the form of time-series. In all three catchments, snowmelt causes a major dilution of the stream water, as reflected by marked dips in electrical conductance. In the most polluted catchment (C2), the snowmelt flood (the major hydrological event at these latitudes) is reflected in the stream water by a pH dip and a pulse in technogenic heavy metals (Cu, Ni, etc.), Al and S. This results from melting of the snow laden with heavy metals and sulphate, and from leaching of the topsoil layer. In the most pristine catchment (C8), snowmelt causes no heavy metal pulse (remote location) but yields an increase in stream water Al (acidic lithology/overburden). In the intermediate catchment (C5), very subdued heavy metal and S increases are noticeable in the stream water, whilst its pH increases steadily until summer (basic lithology). Some elements (Cl, S) may be mobilised out of the snowpack before its complete thawing and reach the stream 1–2 weeks ahead of the heavy metals. The substrate (soil, overburden and bedrock) of a catchment controls to a large extent its ability to buffer acid inputs. 相似文献