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301.
中国东北地区主要地质特征和地壳构造格架 总被引:1,自引:2,他引:1
中国东北地区位于亚洲大陆东缘,发育中国乃至地球上最古老的地质记录、多个时代的古洋岩石圈残片和活动陆缘及陆间碰撞岩浆岩带,具有独特的盆山-山脉相间地貌特征,蕴藏着丰富的自然资源。迄今为止,对于该区古生代构造单元如何划分,一直存在截然不同的认识;对于该区中生代以来的构造格架,缺乏系统的论述。本文在简要介绍现今不同山脉和盆地等地理单元地质特征的基础上,基于断裂构造和地貌特征等方面的资料,把该区新生代构造单元划分为大兴安岭、小兴安岭、阴山-燕山和长白山等4个隆起带,海拉尔-锡林浩特、松辽、三江-兴凯湖和下辽河等4个断陷带。基于岩浆活动和沉积盆地分布,结合区域地球动力学背景,提出了该区晚三叠世至中侏罗世、晚侏罗世、早白垩世早期和早白垩世晚期至古新世等不同阶段构造单元划分的初步方案。基于对已有资料的综合研究,对该区古生代构造单元的特征、松辽盆地的基底组成、早古生代和晚古生代华北克拉通北部边界的位置以及古生代洋盆演化及结束时间等重大地质构造问题,进行了初步探讨,提出了阴山-燕山地区在古生代晚期由克拉通转化为陆缘活化造山带;松辽盆地基底具有与周缘造山系相同的地质组成;该区古生代构造单元是陆缘造山带与碰撞造山带的复合而不是地块拼贴;该区在二叠纪晚期遭受了碰撞造山并在华北北缘形成了高耸的近东西走向的碰撞造山带等新认识。根据洋岩石圈残片和古陆缘岩浆岩的分布,把该区古生代构造单元划分为大兴安岭、阴山-燕山、小兴安岭、张广才岭和老爷岭等5个造山系及华北克拉通,简要介绍了不同造山系的地质特征。 相似文献
302.
Analysis on Structural Control of Coal Distribution in the Northern Qaidam Basin, NW China 总被引:2,自引:1,他引:1
The distribution of the Jurassic coal measures in the northern Qaidam Basin is obviously controlled by the regional structures. Based on the existing data of coalfield exploration and combined with the analysis of coalfield basement structures, features of the main faults, and the distribution of coal measures, this paper brings forward a scheme of coalfield tectonic divisional units and the definition of the coal-controlling structural styles in the northern Qaidam Basin. The structure control of the distribution of coal measures is further discussed. Several stages of regional tectonic activities since the Indosinian has led to the distribution of coal measures into the characteristics of zonation from the north to south and block from east to west. The results indicate that the structural deformations are the most intense in the front of the three uplifted belts, which are characterized by the combination of thrusts. The coal measures are uplifted to the shallow formations, and are easy to be exploited, but the scale of mines is small because of serious damages by the coal distribution. On the contrary, the stress and strain are weak in the three depressions, with the coal-controlling structural styles being mainly the thrust-fold and thrust-monocline combinations. The distribution of coals in the depressions is relatively stable. The shallower part of the depression will become the key areas for exploration and development of coal resources in the northern Qaidam Basin. 相似文献
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304.
Tectonostratigraphy deals with distinguishing megasequences and their interpretation in terms of tectonic settings. It is closely related to sequence stratigraphy and regional tectonics. Tectonosratigraphic units are distinctly displayed on seismic profiles. Examination of megasequences is a reliable tool for regional-scale research. We discuss, using several specific examples, the process of identifying tectonostratigraphic units in various types of sedimentary basins, as well as their relations to chronostratigraphic units. 相似文献
305.
A REVIEW OF THE PALEO-HYDROLOGICAL AND GEOMORPHOLOGICAL CHARACTER OF LAKE NAM CO,SOUTH-CENTRAL TIBET
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The endorheic Lake Nam Co,south Eastern Tibetan Plateau,was selected to investigate the interrelation between drainage basin processes,especially post-glacial glacier decay,and lake level fluctuations.Landforms of the drainage basin are highly influenced by tectonics,superimposed by fluvial and periglacial processes,and locally by glacial and eolian processes.Thus,geomorphological features and hydrological characteristics were compiled for the lake-basin to provide an overview of the landscape character.Data show that during the Last Glacial Maximum melt water from the mountains accumulated fluvial deposits in the foreland.Concurrently,an increase of the lake level occurred which is presently shown by a cliff line all around Nam Co with its base approximately 29m above the present lake level.The Holocene decrease of the lake level is traced by beach ridges.As Nam Co is an endorheic lake post-glacial water loss has to be primarily explained by evaporation and moisture conditions.However,more detailed conclusions on quantitative and chronological patterns of both factors,melt-water input and evaporation output,still remain to be drawn. 相似文献
306.
307.
滇西地区壳体大地构造单元的划分及其演化与运动特征 总被引:7,自引:3,他引:4
以壳体大地构造理论为基础,根据滇西三江地区的基本地质事实,对前人的观点进行重新认识和修正,首次提出了该区迄今最全面、最系统的壳体大地构造单元划分方案,将其细分为4个壳段,11个次级单元和3个挤压聚合带,从新的角度揭示了该区区域地质构造的时空演化规律,为区域成矿规律提供了重要的科学依据。 相似文献
308.
309.
得益于天线波束方位向扫描技术,星载合成孔径雷达(SAR)能够在渐进扫描模式(TOPS)下实现宽测绘带观测.在TOPS模式下,SAR波束沿着方位向进行逆时针反复扫描,并在距离向上进行多次切换,从而获取多个图像切片(burst).为了获得均匀采样的完整成像结果,通常需要对各burst进行重采样,但这会增加额外的计算量,降低处理效率.本文提出了一种宽幅星载TOPSAR数据高效成像算法.首先,在去斜率操作中引入一种新的插值方法,可以灵活地调整最终图像的方位采样间隔,方便进行图像拼接.该方法避免了在聚焦处理前的补零操作,从而降低计算量.在此基础上,本文结合TOPS模式多burst的特点,设计了一种GPU并行处理架构,成倍地提高数据处理效率.最后,根据仿真数据进行了实验,验证了该成像算法的有效性和高效性. 相似文献
310.
基于黄骅坳陷孔南地区大量的钻孔资料和地震资料,通过对孔店组地层厚度的初步复原,识别出了孔店期4个阶段盆地内的凸起与凹陷等构造单元的空间展布特征,恢复了各个阶段陆相断陷盆地的古构造单元,并初步获得了孔店期盆地的演化过程:盆地南北部的古构造单元具有明显的差异性,整体上盆地北部构造单元更为多样、演化过程更为复杂,由单断式盆地向双断式、两凹夹一凸型盆地演化;盆地南部则较为简单,盆地由坳陷型向单断式、再向双断式发展。 相似文献