全文获取类型
收费全文 | 2537篇 |
免费 | 416篇 |
国内免费 | 695篇 |
专业分类
测绘学 | 66篇 |
大气科学 | 31篇 |
地球物理 | 582篇 |
地质学 | 2502篇 |
海洋学 | 172篇 |
天文学 | 6篇 |
综合类 | 172篇 |
自然地理 | 117篇 |
出版年
2024年 | 9篇 |
2023年 | 52篇 |
2022年 | 78篇 |
2021年 | 76篇 |
2020年 | 47篇 |
2019年 | 65篇 |
2018年 | 50篇 |
2017年 | 59篇 |
2016年 | 45篇 |
2015年 | 54篇 |
2014年 | 149篇 |
2013年 | 101篇 |
2012年 | 129篇 |
2011年 | 159篇 |
2010年 | 110篇 |
2009年 | 102篇 |
2008年 | 105篇 |
2007年 | 122篇 |
2006年 | 112篇 |
2005年 | 110篇 |
2004年 | 110篇 |
2003年 | 131篇 |
2002年 | 112篇 |
2001年 | 140篇 |
2000年 | 132篇 |
1999年 | 167篇 |
1998年 | 138篇 |
1997年 | 114篇 |
1996年 | 134篇 |
1995年 | 102篇 |
1994年 | 107篇 |
1993年 | 93篇 |
1992年 | 103篇 |
1991年 | 83篇 |
1990年 | 82篇 |
1989年 | 62篇 |
1988年 | 17篇 |
1987年 | 16篇 |
1986年 | 19篇 |
1985年 | 10篇 |
1984年 | 3篇 |
1981年 | 4篇 |
1975年 | 3篇 |
1973年 | 2篇 |
1960年 | 2篇 |
1951年 | 2篇 |
1948年 | 3篇 |
1947年 | 3篇 |
1946年 | 2篇 |
1933年 | 2篇 |
排序方式: 共有3648条查询结果,搜索用时 15 毫秒
1.
FEASIBLE STUDY ON THE INTEGRATION SYSTEM FOR THE SPACE MONITORING OF MAJOR EARTHQUAKES AND VOLCANOES IN TERRESTRIAL LAND 总被引:1,自引:1,他引:0
BOLi-qun 《中国地理科学(英文版)》2002,12(4):350-353
With the rapid development of space technology, earth observation technology and sky observatory technolo-gy, they have played a more and more important part in monitoring and predicting of earthquakes and volcanoes in the terres-trial land. In recent years, the related agencies have done the experiments and researches on monitoring and predicting ofearthquakes and volcanoes in the forewarning period by means of many approaches, such as satellite thermal infrared re-mote sensing (TIRS), Global Positioning System (GPS), differential interferometric synthesis aperture radar (D-INSAR),astronomical time-latitude residual anomaly, and Geographic Information Systems (GIS), etc. A quite large number of re-search foundation has been built in the fundamental theories and application methods. The experiments and researcheshave shown that these technology is efficient methods for high frequency crust movement. If the existed separate scientificforces and results are possibly assembled together to form a more complete integration monitoring system with the combina-tion of space, sky observation, ground, deep geology and macro anomaly, it will come into a new stage of monitoring andpredicting of earthquakes and volcanic eruptions. 相似文献
2.
3.
4.
在郑州开往南阳的汽车上,老师给我们介绍了花岗岩,还搬出了标本让我们认识。老师告诉我们,花岗岩是由长石、石英和云母三种主要矿物组成,是地下滚烫的岩浆上升过程中,在地壳中冷凝形成的。想到一块小小的石头,却蕴藏了这么多的地球故事与秘密,我的心中便对我们的下一站——宝天曼地质公园充满了向往。终于到了宝天曼地质公园,我看到了雄奇险峻的化石尖,那是一座由灰白色的花岗岩组成的巍丽山峰,海拔1830米。虽然山势险峻,我们的队员们却没有一个畏惧的,大家迫不及待地开始攀登起来。尽管同学们一个个都大汗淋漓,汗湿衣衫,可一想到一会儿到了… 相似文献
5.
6.
WEIHai-quan JINBo-lu LIUYong-shun 《东北亚地学研究》2004,7(1):28-35
A number of different lahars have been recognized from a systematic survey of a mapping project. The high setting temporamre feature of the deposits indicates a relationship between the lahar and the Millennium eruption event of Tianchi Volcano. The lahars caused a dramatic disaster. Recognize of the huge avalanche scars and deposits around Tianchi Volcano imply another highly destructive hazard. Three types of different texture of the avalanche deposits have been recognized. There was often magma mixing processes during the Millennium eruption of Tianchi Volcano, indicating a mixing and co-eruption regime of the eruption. 相似文献
7.
区内火山活动早期为火山爆发成岩;晚期演化为岩浆侵入或隐爆两种成岩方式。矿主要受控于潜火山岩带、放射状断裂破碎带中。成矿是在晚期岩浆活动过程中,所携带的含矿介质叠加和热液作用活化了围岩中有用矿质迁移聚集而成,成矿作用与火山作用有着内在联系。 相似文献
8.
通过对中、上鞍山群变质沉积岩中黑云母化学成分的对比,确认区内两层位黑云母化学组分存在一定差异,这种差异主要反映了其形成时变质条件的不同。随变质程度增加,区内黑云母的Si、AI~Ⅵ,Fe~(3 )、Mg和K含量增加,而Fe~(2 )、Al~Ⅳ和CH降低,Mg/Fe~(2 )比值从1.00增至2.18。中鞍山群黑云母变质温度为550—620℃,变质压力在5×10~8Pa左右;上鞍山群黑云母变质温度为450-500℃,变质压力低于5×10~8Pa。黑云母含铁系数(f)可作为鞍山地区寻找富铁矿的一种标志。 相似文献
9.
10.
AlfonsoBosellini PieroGianolla MarcoStefani 《《幕》》2003,26(3):181-185
The Dolomites region is a spectacularly exposed portion of the Southern Alps, a northern Italian chain derived from the comparatively gentle deformation of the Tethyan passive continental margin of Adria. The regionhad an active Permo-Jurassic tectono-magmatic evolu-tion, leading from Permian magmatism, through a Mid-die Triassic episode offast subsidence and volcanism, to the Jurassic oceanic break-up. Although the sedimentary succession ranges in age from Middle Permian to Creta-ceous, the geological landscape is largely dominated by the majestic Triassic carbonates, making the area a clas-sical one for the early Mesozoic stratigraphy. Particu-larly noteworthy are the Anisian to Carnian carbonate platforms, recording an evolution from regional muddy banks to isolated high-relief builduos. The hlline of the various basins and the development of a last generation of regional peritidal platform followed. The carbonate platforms of the Dolomites bear witness to a remarkable set of changes in the carbonate production and to signif-icant palaeoclimatic fluctuations,from arid to moist con-difions and vice versa; a great range of margin and slope depositional styles is therefore recorded. Alpine tectonic shortening strongly affected the area, with a first Eocenede formation, followed by later Neogene overthrusting and strike-slip movements. 相似文献