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771.
新疆克孜尔水库F2活断层活动特征分析 * 总被引:1,自引:0,他引:1
摘 要 新疆克孜尔水库区内F2活断层的活动规律对水库的安全性有重要影响,对F2断层短水准长序列的观测分析表明:F2断层下盘近40年来持续发生着由南向北的地倾运动。这既影响了短水准高差计算结果,也影响了位错模型水平扭动量和滑动角两个用于评价断层活动性的参数的计算结果,从而使F2断层活动性评价失去客观性。本文通过第1形变监测站人工短水准前尺读数长序列走势分析获得F2活断层下盘测线方向上12米处地倾活动的年变速率(1979-2006)为0.224mm/a,根据库区F2活断层两侧地表沉降速率等值线图确定、验证第1形变监测站上、下盘测线方向上地倾活动年变速率(1991-2002)分别是0.03mm/a、0.07mm/a。对水平扭动量和滑动角的计算和分析表明:F2活断层近10余年来的活动虽与水库蓄水、库水沿活断层下渗、河流改道及地壳运动关系密切,但尚无法认定其活动正在或已经加剧。 相似文献
772.
壁画空鼓病害的探地雷达正演模拟检测 总被引:1,自引:0,他引:1
通常西藏壁画地仗层的厚度不足10cm,有效去除直耦杂波是利用高频探地雷达识别壁画空鼓病害的关键,在此基础上计算空鼓的厚度。模拟制作西藏壁画地仗,在其内部预设深度和厚度各不相同的规则空鼓,通过正演模拟试验确定探地雷达的采集参数,积累数据处理的经验,并比较不同雷达天线的性能。结果表明,针对RAMAC探地雷达和Ground Vision数据采集、后处理软件,时窗深度宜为3ns左右,采样频率应不低于142GHz,效果最明显的两个滤波器是带通滤波和抽取均道。当雷达天线与细泥层地仗耦合较好时,中心频率1.6GHz和2.3GHz的雷达天线均能准确检测出深3cm左右、厚约2cm的空鼓,1.6GHz天线的极限垂直分辨率约0.5 cm。 相似文献
773.
774.
地下盐穴储气库安全性是蓄气运行的关键地质问题.针对平顶山盐田盐层薄、夹层多以及埋藏深等特征,从薄层状盐岩的渗透性、流变性以及稳定性3个方面,详细讨论了储气库的地质可储性及地面沉降问题.首先采集了纯盐岩、互层状盐岩、泥岩夹层3种岩石试样,分别进行了电镜扫描和不同应力水平下的三轴压缩蠕变试验,并应用CYT法对试验区进行了深部盐岩溶腔的探测.鉴于试验区多个采井影响区的重叠,地面沉降量实际监测结果比较复杂,绝对值偏小但具有波动性.综合上述地质特征,作出了平顶山地下盐穴储气库地质条件良好的结论,为我国同类工程提供一定的实际参考. 相似文献
775.
Coprolites can provide detailed information about the nutritional habits and digestive processes of the animals that produced them and may also yield information about the palaeoenvironment in which the animal existed. To test the utility of the lipid biomarker approach to coprolite analysis, lipids were extracted from a coprolite of the Pleistocene ground sloth Nothrotheriops shastensis. Gas chromatography/mass spectrometry results revealed a dominant spiroketal sapogenin component identified, using nuclear magnetic resonance spectroscopy, as epismilagenin. The dominance of epismilagenin is probably due to ingestion of Yucca spp. and Agave spp., which is consistent with previous studies on the diet of this species. 相似文献
776.
Numerous archaeological sites dating to the greek-roman period have been found in the underground of the city of Catania (eastern
Sicily, Italy). Their presence is a testimony of the several settlements that have followed in this area over time. In this
work we have conducted electromagnetic surveys, consisting of ten georadar profiles, inside the church of “S. Agata alla Badia”,
damaged during the earthquake occurred in eastern Sicily on 13 December 1990. The aim was to investigate the area where the
church is located to obtain information useful for its structural recovery. Mechanical drillings were also carried out to
reconstruct the local stratigraphy, which could be complicated by the presence of underground cavities and artefacts, as evidenced
by recent excavations beneath the Catania Cathedral, in the nearby Piazza Duomo. From the interpretation of the GPR data,
the presence of ancient masonry structures underlying the recent foundations was highlighted. In addition, the GPR survey
allowed us to identify and locate reflective horizons in the subsurface, probably due to the presence of materials with different
state of aggregation and/or to buried structures. 相似文献
777.
César Viseras Juan Fernández Fernando García-García Jesús M. Soria María Luisa Calvache Pedro Jáuregui 《Environmental Geology》2009,56(7):1353-1369
An analysis has been made of sedimentary systems involved in the rapid silting of a reservoir constructed in 1974 in Alhama
de Granada (S. Spain); in only 30 years the storage capacity of the reservoir has shrunk by 80% and its perimeter has decreased
by 64%. A study of sediment lithofacies identified in a series of shallow trenches and of georadar facies identified in a
series of almost 900 m lines of ground penetrating radar (GPR) images, together with a survey of surface geology, has identified
3 alluvial systems (2 transversal systems and a longitudinal system) whose deltas have filled in the reservoir. Thus, there
are three phases in the evolution of the reservoir siltation: (1) an initial stage (1974–1977) typified by northward progradation
of the longitudinal river delta of about 100 m year−1 and an eastward progradation of the transversal system delta of about 20 m year−1; (2) an intermediate stage (1977–1984) in which the longitudinal river delta progradation slowed to 25 m year−1 and the axial drainage became obstructed due to the considerable eastward progradation of the transversal delta; and (3)
a final phase (1984–present) in which there have been few changes in the areal distribution of the deltas apart from a southeastward
expansion of the transversal delta. Generally, aggradational growth patterns (vertical accretion) have dominated in this final
phase. The lithology of the source area, the slope and precipitation distribution has a significant effect not only on the
sediment supply, but also indirectly on the creation of accommodation space and on the evolution of stratal growth patterns. 相似文献
778.
CAWS600自动站地温故障检修探讨 总被引:2,自引:0,他引:2
从自动站地温采集原理,引发故障的原因、类型及检查步骤等几个方面对地温故障进行初步探讨. 相似文献
779.
本文用错格实数傅里叶变换的拟谱法的数值模拟方法分析了地震波在冲积扇、盆地等不均匀地震构造体区域的传播过程和地面运动分布. 结果表明, 地震波由岩石区进入盆地结构后,在盆地内上下多次反射振荡,对地面建筑物可能形成多次连续的振动和破坏,仅有极少量地震波能量返回岩石区域中,这是防灾研究中值得注意的地面运动特征;地震波在盆地边界地质构造条件下,形成的地震波体波与次生面波动的叠加干涉形成了大振幅的地面运动,它可能导致建筑物的极大破坏;破坏峰值的空间位置可能远离岩石和盆地沉积层的边界或者地震断层的位置. 相似文献
780.