全文获取类型
收费全文 | 306篇 |
免费 | 7篇 |
专业分类
测绘学 | 6篇 |
大气科学 | 22篇 |
地球物理 | 160篇 |
地质学 | 70篇 |
海洋学 | 3篇 |
天文学 | 29篇 |
综合类 | 1篇 |
自然地理 | 22篇 |
出版年
2019年 | 3篇 |
2018年 | 3篇 |
2017年 | 4篇 |
2016年 | 9篇 |
2015年 | 10篇 |
2014年 | 13篇 |
2013年 | 11篇 |
2012年 | 10篇 |
2011年 | 13篇 |
2010年 | 11篇 |
2009年 | 13篇 |
2008年 | 6篇 |
2007年 | 8篇 |
2004年 | 5篇 |
2003年 | 6篇 |
2002年 | 3篇 |
2001年 | 8篇 |
2000年 | 11篇 |
1999年 | 5篇 |
1998年 | 3篇 |
1997年 | 8篇 |
1996年 | 3篇 |
1993年 | 5篇 |
1992年 | 7篇 |
1990年 | 5篇 |
1989年 | 3篇 |
1987年 | 4篇 |
1983年 | 4篇 |
1982年 | 3篇 |
1981年 | 4篇 |
1980年 | 6篇 |
1979年 | 4篇 |
1977年 | 3篇 |
1976年 | 4篇 |
1975年 | 4篇 |
1971年 | 4篇 |
1970年 | 6篇 |
1969年 | 3篇 |
1968年 | 6篇 |
1967年 | 3篇 |
1966年 | 5篇 |
1965年 | 3篇 |
1963年 | 3篇 |
1960年 | 4篇 |
1959年 | 6篇 |
1958年 | 5篇 |
1957年 | 3篇 |
1956年 | 2篇 |
1954年 | 3篇 |
1948年 | 2篇 |
排序方式: 共有313条查询结果,搜索用时 15 毫秒
311.
Günther Josef Redhammer Anatoliy Senyshyn Gerold Tippelt Clemens Pietzonka Georg Roth Georg Amthauer 《Physics and Chemistry of Minerals》2010,37(5):311-332
CoGeO3 was synthesized at 1,273 and 1,448 K using ceramic sintering techniques in the monoclinic and orthorhombic modification,
respectively. The two compounds were analysed by magnetic susceptibility measurements and neutron diffraction in order to
study magnetic ordering and spin structures at low temperature. The monoclinic form of CoGeO3 has C2/c symmetry and orders magnetically below 36 K with a small negative paramagnetic Curie temperature θ
P = −4.6 (2) K. The magnetic structure can be described with k = (1, 0, 0) in the magnetic space group C2′/c′ having a ferromagnetic spin arrangement within the chains of M1 sites, but a dominating antiferromagnetic coupling between
the chains. At the M1 sites the magnetic spins are aligned within the a–c plane forming an angle of 120° with the +a-axis and they are not parallel to the spins at M2. Here spins are also ferromagnetically coupled within, but antiferromagnetically
coupled between the M1/M2 site bands. The orthorhombic phase of CoGeO3 displays Pbca symmetry and transforms to an antiferromagnetically ordered state [θ
P = −18.6(2) K] below 33 K. The magnetic spin structure can be described with k = (0, 0, 0) in space group Pbca′ and it is similar to the one of the C2/c phase except that it is non-collinear in nature, i.e. there are components of the magnetic moment along all three crystallographic
axes. Small magneto-elastic coupling is observed in the orthorhombic phase. 相似文献
312.
Tom Kol Petr Dobrovolný Pter Szab Tom Mikita Tom Kyncl Josef Kyncl Irena Sochov Ale Flídr David Merta Michal Rybní
ek 《第四纪科学杂志》2022,37(1):123-132
The development of settlement and building activity is the result of socioeconomic, political and demographic changes in the past. However, accurate information on temporal variation in building activity is rather limited. Dendrochronological databases containing dated historical wooden constructions provide an important resource. We used 6514 tree-felling dates to reconstruct building activity in the Czech lands for the period 1450–1950. Comparing felling dates with historical events demonstrated that building activity was negatively associated with intense wars, particularly during the Thirty Years' War (1618–1648). After the Peace of Westphalia (1648), socioeconomic renewal and demographic growth were reflected in an upsurge of building activity, especially ecclesiastical buildings. While the construction of ecclesiastical and noble buildings culminated around the 1720s, rural buildings peaked in the 1780s and the 1820s. Although no direct effect of climate was demonstrated, adverse climatic conditions leading to harvest failures and subsequent famines (e.g. the ‘Hunger Years’ 1770–1772) significantly contributed to declines in building activity. In contrast, a higher number of felling dates were detected when strong and/or frequent windstorms occurred. This study provides a comprehensive understanding of building activity in Central Europe and advocates the use of dendrochronological databases for the investigation of human activities in history. 相似文献
313.
Ladislav Bnesz Josef Hromada Janusz Kozlowski Krzysztof Sobczyk Maciej Pawlikowski 《Geoarchaeology》1995,10(4):237-255
The site of Moravany-Žakovska in western Slovakia is situated in a loessic terrain and is dated to the end of the Late Glacial Maximum. This article shows the importance of analyzing the 0.01-0.1 mm fraction to interpret the sedimentological environment and a number of measured anthropogenic indices, such as burnt quartz grains, charcoal, radiolarite chips, microflakes, and microfragments of bone. Analysis of the profile of the site through time reveals the relationship between occupational levels and phases of slope wash that occurred during wetter climatic episodes; these are separated by phases of aeolian sedimentation. At the same time, analysis of anthropogenic indices in this size fraction permitted the identification of occupational levels, including those not recorded by macrofinds. Analysis of anthropogenic indices in horizontal exposures enabled the identification of latent settlement structures such as hearths, areas of radiolarite processing, zones where mineral dyes were prepared, and other structures not recorded by macrofinds. 相似文献