全文获取类型
收费全文 | 170篇 |
免费 | 3篇 |
国内免费 | 19篇 |
专业分类
测绘学 | 7篇 |
大气科学 | 20篇 |
地球物理 | 39篇 |
地质学 | 69篇 |
海洋学 | 18篇 |
天文学 | 29篇 |
综合类 | 1篇 |
自然地理 | 9篇 |
出版年
2023年 | 2篇 |
2021年 | 7篇 |
2020年 | 1篇 |
2019年 | 4篇 |
2018年 | 10篇 |
2017年 | 9篇 |
2016年 | 9篇 |
2015年 | 9篇 |
2014年 | 9篇 |
2013年 | 10篇 |
2012年 | 9篇 |
2011年 | 16篇 |
2010年 | 16篇 |
2009年 | 10篇 |
2008年 | 12篇 |
2007年 | 17篇 |
2006年 | 9篇 |
2005年 | 2篇 |
2004年 | 6篇 |
2003年 | 3篇 |
2002年 | 5篇 |
2001年 | 4篇 |
2000年 | 3篇 |
1999年 | 2篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1988年 | 1篇 |
1977年 | 1篇 |
排序方式: 共有192条查询结果,搜索用时 15 毫秒
41.
High-Mg lavas are characteristic of the mid-Miocene volcanism in Inner Asia.In the Vitim Plateau,small volume high-Mg volcanics erupted at 16-14 Ma.and were followed with voluminous moderate-Mg lavas at 14-13 Ma.In the former unit,we have recorded a sequence of(1) initial basaltic melts,contaminated by crustal material,(2) uncontaminated high-Mg basanites and basalts of transitional(K-Na-K) compositions,and(3) picrobasalts and basalts of K series;in the latter unit a sequence of(1) initial basalts and basaltic andesites of transitional(Na-K-Na) compositions and(2) basalts and trachybasalts of K-Na series.From pressure estimation,we infer that the high-Mg melts were derived from the sublithospheric mantle as deep as 150 km,unlike the moderate-Mg melts that were produced at the shallow mantle.The 14-13 Ma rock sequence shows that initial melts equilibrated in a garnet-free mantle source with subsequently reduced degree of melting garnet-bearing material.No melting of relatively depleted lithospheric material,evidenced by mantle xenoliths,was involved in melting,however.We suggest that the studied transition from high-to moderate-Mg magmatism was due to the mid-Miocene thermal impact on the lithosphere by hot sub-lithospheric mantle material from the Transbaikalian low-velocity(melting) domain that had a potential temperature as high as 1510℃.This thermal impact triggered rifting in the lithosphere of the Baikal Rift Zone. 相似文献
42.
The limited area model MAR (Modèle Atmosphérique Régional) is validated over the Antarctic Plateau for the period 2004–2006,
focussing on Dome C during the cold season. MAR simulations are made by initializing the model once and by forcing it through
its lateral and top boundaries by the ECMWF operational analyses. Model outputs compare favourably with observations from
automatic weather station (AWS), radiometers and atmospheric soundings. MAR is able to simulate the succession of cold and
warm events which occur at Dome C during winter. Larger longwave downwelling fluxes (LWD) are responsible for higher surface
air temperatures and weaker surface inversions during winter. Warm events are better simulated when the small Antarctic precipitating
snow particles are taken into account in radiative transfer computations. MAR stratosphere cools during the cold season, with
the coldest temperatures occurring in conjunction with warm events at the surface. The decrease of saturation specific humidity
associated with these coldest temperatures is responsible for the formation of polar stratospheric clouds (PSCs) especially
in August-September. PSCs then contribute to the surface warming by increasing the surface downwelling longwave flux. 相似文献
43.
We compute the characteristic parameters of the magneto-dipole radiation of a neutron star undergoing torsional seismic vibrations under the action of Lorentz restoring force about an axis of a dipolar magnetic field experiencing decay.After a brief outline of the general theoretical background of the model of a vibration-powered neutron star,we present numerical estimates of basic vibration and radiation characteristics,such as frequency,lifetime and luminosity,and investigate their time dependence on magn... 相似文献
44.
Irina V. Kurina Elena E. Veretennikova Anna A. Il’ina Marina L. Egorova Lyudmila V. Salisch Vladimir N. Dolgin Albert V. Udaloi Evgeniya A. Golovatskaya Egor A. Dyukarev Sergei V. Smirnov 《Boreas: An International Journal of Quaternary Research》2023,52(2):223-239
Palaeoenvironmental reconstructions from peat are strongly focused on ombrotrophic mires, but this study demonstrates that eutrophic mires can also be used. A multi-proxy approach was applied to a eutrophic mire on a floodplain terrace in the southern taiga of West Siberia. The results of the reconstruction were considered in the wide geographic context of the surrounding regions, including Siberia and Central Asia. Different palaeoecological proxies (analysis of plant macrofossils, testate amoebae, oribatid mites, molluscs, peat humification, ash content and spectral characteristics of humic acids) were used in this study. The results of different proxies showed a high level of consistency among themselves, which allowed for a robust interpretation of Holocene mire development. Throughout the ~7800 years history of the mire, there was a high level of surface wetness. The presence of mineral matter in the peat between 7800 and 5100 cal. a BP indicates regular flooding caused by the intensive fluvial activity, apparently resulting from increased precipitation. This was followed by a trend towards a gradual decrease in surface wetness from conditions of high surface moisture (stagnant water) between 5100 and 3000 cal. a BP to present day conditions of moderate surface moisture with a water table slightly below the mire surface. This pattern is consistent with the well-documented long-term trend from palaeoecological records throughout the taiga and arctic zones in West Siberia and central arid Asia. Our data further support the idea that the westerlies were the dominant driver of climate for the southern taiga of West Siberia during the Middle to Late Holocene. 相似文献
45.
Pepler Acacia S. Dowdy Andrew J. van Rensch Peter Rudeva Irina Catto Jennifer L. Hope Pandora 《Climate Dynamics》2021,56(1-2):681-682
Climate Dynamics - In the original published version of the paper, the figures reported in Sect. 4 relating the proportion of rainfall in southern Australia that is due to each of the... 相似文献
46.
47.
Seismic anisotropy and mantle creep in young orogens 总被引:9,自引:0,他引:9
48.
Irina A. Bilenko 《Solar physics》2004,221(2):261-282
The longitudinal distribution of coronal holes has been analyzed for the time interval 1976–2002. Coronal holes don't seem
to be randomly distributed. The cluster structure has been revealed in the time—space organization of coronal hole distribution.
The complexity and lifetime of clusters depend on the solar cycle phase. The comparison of active region and coronal hole
cluster structures shows that some coronal hole clusters as well as active region ones occur almost simultaneously in both
hemispheres, some clusters in the north or in the south hemisphere only. Some coronal hole clusters coincide with the active
region clusters and some do not coincide. They reflect the large-scale solar magnetic field distribution. 相似文献
49.
Stéphane Reboulet Peter F. Rawson Josep A. Moreno-Bedmar Maria B. Aguirre-Urreta Ricardo Barragán Yuri Bogomolov Miguel Company Celestina González-Arreola Vyara Idakieva Stoyanova Alexander Lukeneder Bertrand Matrion Vasily Mitta Hasina Randrianaly Zdenek Vaši?ek Evgenij J. Baraboshkin Didier Bert Stéphane Bersac Tamara N. Bogdanova Luc G. Bulot Jean-Louis Latil Irina A. Mikhailova Pierre Ropolo Ottilia Szives 《Cretaceous Research》2011,32(6):786-793
The 4th Kilian Group meeting (Dijon, France, 30th August 2010) focused on the Aptian and Albian Stages. For the Aptian, a two-fold division of the stage was adopted for the Mediterranean area with a boundary between the Dufrenoyia furcata and Epicheloniceras martini Zones. The main changes to the zonal scheme concern the Lower Aptian with: the introduction of a Deshayesites luppovi Subzone in the upper part of the Deshayesites oglanlensis Zone; the replacement of Deshayesites weissi by Deshayesites forbesi as new index-species of the second interval zone; the introduction of a Roloboceras hambrovi Subzone in the upper part of the D. forbesi Zone; and the subdivision of the D. furcata Zone into the D. furcata and Dufrenoyia dufrenoyi Subzones. For the Albian, the upper part of the Douvilleiceras mammillatum Zone (Lower Albian) is now characterized by a Lyelliceras pseudolyelli Subzone. The main amendments concern the Upper Albian. The base of this substage is defined by the base of the Dipoloceras cristatum Zone. Above it, the Upper Albian zonal scheme comprises in stratigraphic order the Mortoniceras pricei, Mortoniceras inflatum, Mortoniceras fallax, Mortoniceras rostratum, Mortoniceras perinflatum and Arrhaphoceras briacensis Zones. 相似文献
50.