全文获取类型
收费全文 | 126篇 |
免费 | 7篇 |
专业分类
测绘学 | 2篇 |
大气科学 | 8篇 |
地球物理 | 43篇 |
地质学 | 48篇 |
海洋学 | 5篇 |
天文学 | 21篇 |
综合类 | 2篇 |
自然地理 | 4篇 |
出版年
2022年 | 1篇 |
2021年 | 3篇 |
2020年 | 5篇 |
2019年 | 2篇 |
2018年 | 4篇 |
2017年 | 6篇 |
2016年 | 5篇 |
2015年 | 4篇 |
2014年 | 6篇 |
2013年 | 5篇 |
2012年 | 10篇 |
2011年 | 3篇 |
2010年 | 4篇 |
2009年 | 7篇 |
2008年 | 6篇 |
2007年 | 3篇 |
2006年 | 5篇 |
2005年 | 3篇 |
2004年 | 4篇 |
2003年 | 2篇 |
2002年 | 3篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1999年 | 2篇 |
1997年 | 2篇 |
1996年 | 3篇 |
1995年 | 3篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1991年 | 1篇 |
1990年 | 3篇 |
1989年 | 3篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 3篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有133条查询结果,搜索用时 0 毫秒
21.
Virginia B. Sisson 《Contributions to Mineralogy and Petrology》1987,95(1):123-131
During hydrothermal fluid activity associated with the intrusion of the Ponder pluton, Coast Plutonic Complex, British Columbia, Canada, the halogen composition of biotite, amphibole and apatite is controlled by the composition of the metamorphic fluid. The core of the pluton was not affected by infiltrating fluids, and the fluorine composition of biotite was controlled by the biotite Fe-Mg ratio. The edge of the cooling, crystallized pluton interacted with a chlorine-rich, fluorine-poor fluid which changed the halogen composition of biotite and amphibole. The composition of the metamorphic fluid derived from biotite and apatite compositions was relatively high in chlorine and low in fluorine. The concentration of chlorine in the metamorphic fluid increases towards the pluton, whereas fluorine remains constant. This suggests that the metamorphic fluid near the pluton had the greatest potential for masstransfer of metals. 相似文献
22.
Willard S. Moore Teh-Lung Ku J. Douglas Macdougall Virginia Mee Burns Roger Burns Jack Dymond Mitchel W. Lyle David Z. Piper 《Earth and Planetary Science Letters》1981,52(1):151-171
Fluxes of metals to the top and bottom surfaces of a manganese nodule were determined by combining radiochemical (230Th,231Pa,232Th,238U,234U) and detailed chemical data. The top of the nodule had been growing in its collected orientation at 4.7 mm Myr?1 for at least 0.5 Myr and accreting Mn at 200 μg cm?2 kyr?1. The bottom of the nodule had been growing in its collected orientation at about 12 mm Myr?1 for at least 0.3 Myr and accreting Mn at about 700 μg cm?2 yr?1. Although the top of the nodule was enriched in iron relative to the bottom, the nodule had been accreting Fe 50% faster on the bottom.232Th was also accumulating more rapidly in the bottom despite a 20-fold enrichment of230Th on the top.The distribution of alpha-emitting nuclides calculated from detailed radiochemical measurements matched closely the pattern revealed by 109-day exposures of alpha-sensitive film to the nodule. However, the shape and slope of the total alpha profile with depth into the nodule was affected strongly by226Ra and222Rn migrations making the alpha-track technique alone an inadequate method of measuring nodule growth rates.Diffusion of radium in the nodule may have been affected by diagenetic reactions which produce barite, phillipsite and todorokite within 1 mm of the nodule surface; however, our sampling interval was too broad to document the effect. We have not been able to resolve the importance of nodule diagenesis on the gross chemistry of the nodule. 相似文献
23.
24.
Virginia M. Oversby 《Earth and Planetary Science Letters》1980,49(2):252-258
The choice of diagrammatic representation for Pb isotope data should be determined by clarity of presentation and ability of the chosen diagram to highlight significant differences between samples. The conventionally used [α, β] diagram is shown to be superior to the recently proposed [I, S] diagram in both these respects. Transformation of Pb data to achieve parametric forms which can be treated by linear statistical methods causes a loss of diagnostic sensitivity, particularly for relatively young events. This loss of sensitivity argues against use of the parametric [I, S] diagram. 相似文献
25.
26.
27.
28.
Large wood clogging during floods in a gravel‐bed river: the Długopole bridge in the Czarny Dunajec River,Poland 下载免费PDF全文
Virginia Ruiz‐Villanueva Bartłomiej Wyżga Paweł Mikuś Maciej Hajdukiewicz Markus Stoffel 《地球表面变化过程与地形》2017,42(3):516-530
During floods, large quantities of wood can be mobilized and transported downstream. At critical sections, such as bridges, the transported wood might be entrapped and a quick succession of backwater effects can occur as a result of the reduction of the cross‐sectional area. The aim of this work is to explore large wood‐related hazards during floods in the gravel‐bed river Czarny Dunajec (Polish Carpathians), where the river flows through the village of D?ugopole. This work is based on the numerical modelling of large wood transport together with flow dynamics in which inlet and boundary conditions were designed based on field observations. The exploratory approach developed in this study uses multiple scenarios (193) to analyse the factors controlling bridge clogging: wood size, wood supply, flow conditions, morphology and obstacles in the riverbed. Results highlighted the strong control of log length (stronger than that of log diameter) on potential blockage probability; however, according to our results the main factor controlling bridge clogging was the flood discharge. River morphology and wood supply play an important role as well. The river morphology may reduce bridge blockage, as it influences flow velocity and depth, and creates natural retention zones for wood. In addition, the impacts of bridge blockage were analysed in terms of afflux depth and length, and flooded area. Results showed that bridge blockage may result in a significant increase in water depth (up to 0.7 m) and flooded area (up to 33% more), therefore increasing flood risk in the village. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
29.
W. G. Ernst Barbara L. Dutrow Virginia Sisson Sarah Penniston-Dorland 《International Geology Review》2017,59(5-6):523-525
ABSTRACTThis is a preface to the topical issue entitled ‘Subduction, Fluids, and Accessory Minerals: A Celebration of the Career of Sorena S. Sorensen’ 相似文献
30.
Jos L. Pea‐Monn Virginia Rubio‐Fernndez Luis A. Longares‐Aladrn Francisco J. Gutirrez‐Gonzlez Fernando Prez‐Lambn Carlos Laliena‐Corbera 《Geoarchaeology》2014,29(6):448-461
An interdisciplinary non‐invasive research strategy combining the analysis of archival documents, detailed geomorphological mapping, Quaternary stratigraphic studies, analysis of ceramics, and radiocarbon dating was designed to reconstruct the evolution of the Mezimegeer–Juslibol Castle, northeastern Spain. This fortress had great strategic importance in the siege and conquest of the nearby Islamic city of Saraqusta by the Christians in A.D. 1118. The castle and moat complex was built in the mid‐10th century. In the mid‐12th century, its rapid degradation began, as it is shown by this geoarchaeological study of the sediments in the moats. Its present state of decay is due to later erosion that is promoted by the unstable bedrock of Miocene gypsum, highly deformed gravels that form a Pleistocene fluvial terrace, and the environmental aridity. 相似文献