全文获取类型
收费全文 | 175篇 |
免费 | 4篇 |
国内免费 | 2篇 |
专业分类
测绘学 | 2篇 |
大气科学 | 33篇 |
地球物理 | 49篇 |
地质学 | 61篇 |
海洋学 | 6篇 |
天文学 | 14篇 |
自然地理 | 16篇 |
出版年
2024年 | 1篇 |
2023年 | 1篇 |
2022年 | 2篇 |
2021年 | 4篇 |
2020年 | 1篇 |
2019年 | 3篇 |
2018年 | 10篇 |
2017年 | 6篇 |
2016年 | 9篇 |
2015年 | 8篇 |
2014年 | 8篇 |
2013年 | 9篇 |
2012年 | 9篇 |
2011年 | 5篇 |
2010年 | 7篇 |
2009年 | 7篇 |
2008年 | 9篇 |
2007年 | 12篇 |
2006年 | 18篇 |
2005年 | 9篇 |
2004年 | 5篇 |
2003年 | 10篇 |
2002年 | 6篇 |
2000年 | 3篇 |
1999年 | 2篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1992年 | 4篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1983年 | 2篇 |
1981年 | 1篇 |
排序方式: 共有181条查询结果,搜索用时 31 毫秒
121.
Fabrice R. Fontaine Guilhem Barruol réa Tommasi Götz H. R. Bokelmann 《Geophysical Journal International》2007,170(3):1262-1288
Upper-mantle flow beneath the South Pacific is investigated by analysing shear wave splitting parameters at eight permanent long-period and broad-band seismic stations and 10 broad-band stations deployed in French Polynesia from 2001 to 2005 in the framework of the Polynesian Lithosphere and Upper Mantle Experiment (PLUME). Despite the small number of events and the rather poor backazimuthal coverage due to the geographical distribution of the natural seismicity, upper-mantle seismic anisotropy has been detected at all stations except at Tahiti where two permanent stations with 15 yr of data show an apparent isotropy. The median value of fast polarization azimuths (N67.5°W) is parallel to the present Pacific absolute plate motion direction in French Polynesia (APM: N67°W). This suggests that the observed SKS fast polarization directions result mainly from olivine crystal preferred orientations produced by deformation in the sublithospheric mantle due to viscous entrainment by the moving Pacific Plate and preserved in the lithosphere as the plate cools. However, analysis of individual measurements highlights variations of splitting parameters with event backazimuth that imply an actual upper-mantle structure more complex than a single anisotropic layer with horizontal fast axis. A forward approach shows that a two-layer structure of anisotropy beneath French Polynesia better explains the splitting observations than a single anisotropic layer. Second-order variations in the measurements may also indicate the presence of small-scale lateral heterogeneities. The influence of plumes or fracture zones within the studied area does not appear to dominate the large-scale anisotropy pattern but may explain these second-order splitting variations across the network. 相似文献
122.
Aurore Voldoire Bas Eickhout Michiel Schaeffer Jean-François Royer Fabrice Chauvin 《Climate Dynamics》2007,29(2-3):177-193
To include land-use dynamics in a general circulation model (GCM), the physical system has to be linked to a system that represents
socio-economy. This issue is addressed by coupling an integrated assessment model, IMAGE2.2, to an ocean–atmosphere GCM, CNRM-CM3.
In the new system, IMAGE2.2 provides CNRM-CM3 with all the external forcings that are scenario dependent: greenhouse gas (GHGs)
concentrations, sulfate aerosols charge and land cover. Conversely, the GCM gives IMAGE changes in mean temperature and precipitation.
With this new system, we have run an adapted scenario of the IPCC SRES scenario family. We have chosen a single scenario with
maximum land-use changes (SRES A2), to illustrate some important feedback issues. Even in this two-way coupled model set-up,
land use in this scenario is mainly driven by demographic and agricultural practices, which overpowers a potential influence
of climate feedbacks on land-use patterns. This suggests that for scenarios in which socio-economically driven land-use change
is very large, land-use changes can be incorporated in GCM simulations as a one-way driving force, without taking into account
climate feedbacks. The dynamics of natural vegetation is more closely linked to climate but the time-scale of changes is of
the order of a century. Thus, the coupling between natural vegetation and climate could generate important feedbacks but these
effects are relevant mainly for multi-centennial simulations. 相似文献
123.
Jean-Lambert Join Bernard Robineau Jean-Paul Ambrosi Claire Costis Fabrice Colin 《Comptes Rendus Geoscience》2005,337(16):1500-1508
Ultramafic rocks outcrop over more than one third of New Caledonia's main island. Under tropical conditions, thick lateritic mantles with nickel concentrations developed on these rocks by geochemical weathering. Groundwater in ultramafic mined massifs represents a valuable resource, but also a severe constrain for mining engineering. Previous works describe several water tables in the various layers of the weathering mantle. From a hydrologic study of the Tiebaghi massif, the hydraulic continuity across the weathering layers down to the bedrock is proposed. To cite this article: J.-L. Join et al., C. R. Geoscience 337 (2005). 相似文献
124.
Nevila Jozja Patrick Baillif Jean-Claude Touray Charles-Henri Pons Fabrice Muller Carole Burgevin 《Comptes Rendus Geoscience》2003,335(9):729-736
The article addresses the structural effects of solutions of lead nitrate on a suspended or compacted bentonite. A permeability increase is observed on compacted clay. Investigating the composition of output solution, using X-Rays Diffusion at Small Angles and Scanning Electron Microscopy, this permeability increase is explained from structural variations at nanometric (reduction of particle size) and micrometric scales (microfissuration of aggregates). To cite this article: N. Jozja et al., C. R. Geoscience 335 (2003). 相似文献
125.
Toyoda Takahiro Fujii Yosuke Kuragano Tsurane Kosugi Naohiro Sasano Daisuke Kamachi Masafumi Ishikawa Yoichi Masuda Shuhei Sato Kanako Awaji Toshiyuki Hernandez Fabrice Ferry Nicolas Guinehut Stéphanie Martin Matthew Andrew Peterson K. Good Simon A. Valdivieso Maria Haines Keith Storto Andrea Masina Simona Köhl Armin Yin Yonghong Shi Li Alves Oscar Smith Gregory Chang You-Soon Vernieres Guillaume Wang Xiaochun Forget Gael Heimbach Patrick Wang Ou Fukumori Ichiro Lee Tong Zuo Hao Balmaseda Magdalena 《Climate Dynamics》2017,49(3):891-907
Climate Dynamics - The interannual-decadal variability of the wintertime mixed layer depths (MLDs) over the North Pacific is investigated from an empirical orthogonal function (EOF) analysis of an... 相似文献
126.
Fabrice Brunet Christian Chopin Friedrich Seifert 《Contributions to Mineralogy and Petrology》1998,131(1):54-70
The polymorphic relations for Mg3(PO4)2 and Mg2PO4OH have been determined by reversed experiments in the temperature-pressure (T-P) range 500–1100 °C, 2–30 kbar. The phase transition between the low-pressure phase farringtonite and Mg3(PO4)2-II, the Mg analogue of sarcopside, is very pressure dependent and was tightly bracketed between 625 °C, 7 kbar and 850 °C,
9 kbar. The high-temperature, high-pressure polymorph, Mg3(PO4)2-III, is stable above 1050 °C at 10 kbar and above 900 °C at 30 kbar. The low-pressure stability of farringtonite is in keeping
with its occurrence in meteorites. The presence of iron stabilizes the sarcopside-type phase towards lower P. From the five Mg2PO4OH polymorphs only althausite, holtedahlite, β-Mg2PO4OH (the hydroxyl analogue of wagnerite) and ɛ-Mg2PO4OH were encountered. Relatively speaking, holtedahlite is the low-temperature phase (<600 °C), ɛ-Mg2PO4OH the high-temperature, low-pressure phase and β-Mg2PO4OH the high-temperature, high-pressure phase, with an intervening stability field for althausite which extends from about
3 kbar at 500 °C to about 12 kbar at 800 °C. Althausite and holtedahlite are to be expected in F-free natural systems under
most geological conditions; however, wagnerite is the most common Mg-phosphate mineral, implying that fluorine has a major
effect in stabilizing the wagnerite structure. Coexisting althausite and holtedahlite from Modum, S. Norway, show that minor
fluorine is strongly partitioned into althausite (KD
F/OH≈ 4) and that holtedahlite may incorporate up to 4 wt% SiO2. Synthetic phosphoellenbergerite has a composition close to (Mg0.9□0.1)2Mg12P8O38H8.4. It is a high-pressure phase, which breaks down to Mg2PO4OH + Mg3(PO4)2 + H2O below 8.5 kbar at 650 °C, 22.5 kbar at 900 °C and 30 kbar at 975 °C. The stability field of the phosphate end-member of
the ellenbergerite series extends therefore to much lower P and higher T than that of the silicate end-members (stable above 27 kbar and below ca. 725 °C). Thus the Si/P ratio of intermediate members
of the series has a great barometric potential, especially in the Si-buffering assemblage with clinochlore + talc + kyanite
+ rutile + H2O. Application to zoned ellenbergerite crystals included in the Dora-Maira pyrope megablasts, western Alps, reveals that growth
zoning is preserved at T as high as 700–725 °C. However, the record of attainment of the highest T and/or of decreasing P through P-rich rims (1 to 2 Si pfu) is only possible in the presence of an additional phosphate phase (OH-bearing or even
OH-dominant wagnerite in these rocks), otherwise the trace amounts of P in the system remain sequestered in the core of Si-rich
crystals (5 to 8 Si pfu) and can no longer react.
Received: 7 April 1995 / Accepted: 12 November 1997 相似文献
127.
R. A. Pielke W. R. Cotton R. L. Walko C. J. Tremback W. A. Lyons L. D. Grasso M. E. Nicholls M. D. Moran D. A. Wesley T. J. Lee J. H. Copeland 《Meteorology and Atmospheric Physics》1992,49(1-4):69-91
Summary This paper presents a range of applications of the Regional Atmospheric Modeling System (RAMS), a comprehensive mesoscale meterological modeling system. Applications discussed in this paper include large eddy simulations (LES) and simulations of thunderstorms, cumulus fields, mesoscale convective systems, mid-latitude cirrus clouds, winter storms, mechanically- and thermally-forced mesoscale systems, and mesoscale atmospheric disperision. A summary of current RAMS options is also presented. Improvements to RAMS currently underway include refinements to the cloud radiation, cloud microphysics, cumulus, and surface soil/vegetative parameterization schemes, the parallelization of the code, development of a more versatile visualization capability, and research into meso--scale cumulus parameterization.With 18 Figures 相似文献
128.
129.
Contributions to Mineralogy and Petrology - The new phosphate bearthite, Ca2Al(PO4)2HO, found in high-pressure metamorphic rocks, has been synthesized from a stoichiometric mixture of γ-Al2O3... 相似文献
130.
Numerical simulation of meso-β-scale convective cloud systems associated with a PRE-STORM MCC case has been carried out using a 2-D version of the CSU Regional Atmospheric Modeling System (RAMS) nonhydrostatic model with parameterized microphysics. It is found that the predicted meso-γ-scale convective phenomena are basically unsteady under the situation of strong shear at low-levels, white the meso-β-scale convective system is maintained up to 3 hours or more. The meso-β-scale cloud system exhibits characteristics of a multi-celled convective storm in which the meso-γ-scale convective cells have lifetime of about 30 min. Pressure perturbation depicts a meso-low after a half hour in the low levels. As the cloud system evolves, the meso-low inten-sifies and extends to the upshear side and covers the entire domain in the mid-lower levels with the peak values of 5-8 hPa. Temperature perturbation depicts a warm region in the middle levels through the entire simulation period. The meso-γ-scale warm cores with peak values of 4-8oC are associated with strong convective cells. The cloud top evapo-ration causes a stronger cold layer around the cloud top levels.Simulation of microphysics exhibits that graupel is primarily concentrated in the strong convective cells forming the main source of convective rainfall after one hour of simulation time. Aggregates are mainly located in the stratiform region and decaying convective cells which produce the stratiform rainfall. Riming of the ice crystals is the predominant precipitation formation mechanism in the convection region, whereas aggregation of ice crystals is the predominant one in the stratiform region, which is consistent with observations. Sensitivity experiments of ice-phase microphysical processes show that the microphysical structures of the convective cloud system can be simulated better with the diagnosed aggregation collection efficiencies. 相似文献