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991.
大地电磁测深法在福建漳州地热区的应用 总被引:1,自引:0,他引:1
为了研究漳州地区深部构造和热源条件,在天宝、漳州、龙海一线进行了大地电磁测深测量工作。通过对大地电磁测深结果的分析和解释,表明在漳州地区龙海—浮宫一带上地幔高导基底明显上隆,在壳内10—13km深处具有明显的高导层,地表覆盖层电阻率很低。根据这些情况并结合地质资料推断,这一带地下存在着温度较高的热源及地下水补给条件,在地下水深循环和热对流良好的断裂交汇区,有可能形成水温较高的地热田。 相似文献
992.
993.
994.
中国东北部晚中生代断陷盆地模式在松辽深部煤成气预测中的可能应用 总被引:1,自引:0,他引:1
Li Sitian Wu Chonglong 《地球科学》1986,(5)
经地震探测和地质分析,松辽深部晚中生代断陷盆地与其周围地区J_3—K_1的断陷盆地在地质结构和成盆期均具有相似性,同属东北亚晚中生代断陷盆地系。作者认为,应用其周围同类型断陷盆地模式对松辽深部煤成气远景的预测和生油潜力的判断具有重要价值,同样也适用于深埋于下辽河第三纪坳陷之下的晚中生代盆地成气远景的预测。 相似文献
995.
该区晚二叠世分合山和大隆两个组。文章从岩石特征,沉积构造、古生物化石群组和遗迹化石方面论述了其沉积环境特征。合山组在桂中地区为含煤岩系,煤层顶底板是灰岩和硅质岩。古生物化石较单一,以裸松藻科为主,有少量有孔虫、(竹蜓)、介形虫和腕足类海百合的碎屑。遗迹化石以居住潜穴Skolithos为主。研究证明,合山组属低能潮坪环境。大隆组在该区出露不足10m,以凝灰岩、硅质岩和硅质泥岩为主。浊流沉积特征明显以鲍马层序中A.C.E段最为发育。并在硅质泥岩中,发现半深水遗迹化石Chondrites,Planolites和Rind Burrow等,说明大隆组属深水或半深水沉积环境。合山与大隆两组的接触界线不清,尚待研究。 相似文献
996.
本文根据鄂东南地区的成矿规律和矿床特征,着重讨论了几个已知矿区深部矿体与综合物探信息之间的关系;通过部分野外工作和大量的计算,对区内阳新岩体西北端进行了深部成矿预测;并指出了在深部找矿过程中应注意的几个问题。 相似文献
997.
H M Iyer V K Gaur S S Rai D S Ramesh CVR Rao D Srinagesh K Suryaprakasam 《Journal of Earth System Science》1989,98(1):31-60
Analysis of teleseismicP-wave residuals observed at 15 seismograph stations operated in the Deccan volcanic province (DVP) in west central India points
to the existence of a large, deep anomalous region in the upper mantle where the velocity is a few per cent higher than in
the surrounding region. The seismic stations were operated in three deployments together with a reference station on precambrian
granite at Hyderabad and another common station at Poona. The first group of stations lay along a west-northwesterly profile
from Hyderabad through Poona to Bhatsa. The second group roughly formed an L-shaped profile from Poona to Hyderabad through
Dharwar and Hospet. The third group of stations lay along a northwesterly profile from Hyderabad to Dhule through Aurangabad
and Latur. Relative residuals computed with respect to Hyderabad at all the stations showed two basic features: a large almost
linear variation from approximately +1s for teleseisms from the north to—1s for those from the southeast at the western stations,
and persistance of the pattern with diminishing magnitudes towards the east. Preliminary ray-plotting and three-dimensional
inversion of theP-wave residual data delineate the presence of a 600 km long approximately N−S trending anomalous region of high velocity (1–4%
contrast) from a depth of about 100 km in the upper mantle encompassing almost the whole width of the DVP. Inversion ofP-wave relative residuals reveal the existence of two prominent features beneath the DVP. The first is a thick high velocity
zone (1–4% faster) extending from a depth of about 100 km directly beneath most of the DVP. The second feature is a prominent
low velocity region which coincides with the westernmost part of the DVP. A possible explanation for the observed coherent
high velocity anomaly is that it forms the root of the lithosphere which coherently translates with the continents during
plate motions, an architecture characteristic of precambrian shields. The low velocity zone appears to be related to the rift
systems (anomaly 28, 65 Ma) which provided the channel for the outpouring of Deccan basalts at the close of the Cretaceous
period. 相似文献
998.
青藏高原莫霍面的研究进展 总被引:13,自引:2,他引:13
本文首先简要回顾了莫霍面的发现,介绍其基本性质,然后对青藏高原莫霍面研究的重要进展进行了评述。在区域尺度上,被动源地震(天然地震)方法研究结果勾勒出青藏高原地壳及岩石圈底部的深部构造轮廓。然而受分辨率的限制,天然地震结果给出的地壳及上地幔结构的细节不足。近年来已经用分辨率达到几千米甚至百米级的主动源地震(包括宽角反射与折射地震和深反射地震)方法,揭示出青藏高原地壳及上地幔的精细结构。本文对近30年来深地震探测获得的青藏高原各个地块的莫霍面深度、壳幔结构和上地幔盖层速度等基本数据进行了较系统的分析,并对青藏高原莫霍面研究存在的有关问题进行了讨论。 相似文献
999.
Airborne very low frequency (VLF) data are routinely collected by national agencies and commercial companies together with
other passive geophysical measurements of the static magnetic field and radiometric data. The purpose of this paper is to
demonstrate that both standard three-component VLF and tensor VLF (TVLF) data contain a lot of useful quantitative and qualitative
information about the electrical conductivity distribution in the upper few hundred meters of the crystalline basement. We
first give a new derivation of the fundamental transfer functions (the tipper) used in the TVLF technique. We then show that
the tipper can be estimated from simultaneous measurements of the wave magnetic fields from at least two transmitters with
somewhat different frequencies, and present a simple model by which the maximum error introduced by the difference in frequencies
can be found. Single transmitter scalar VLF maps emphasise those conductive structures that have dominant strikes in the direction
of the transmitter. Multiple transmitter transfer functions are dependent only upon the underlying conductivity structure.
Two dimensional structures can be quantitatively modelled by modern inversion methods developed originally for deep electromagnetic
magnetotelluric (MT) soundings. In such cases three-component VLF measurements can be modelled easily upon appropriate rotation
of the co-ordinate system to “strike” co-ordinates. Single frequency transfer functions (tippers) have real and imaginary
parts that carry information on not only lateral contrasts in conductivity, as usually stated in text books, but, taken together,
they provide a robust tool for determining the background conductivity level away from distinct conductors, and they can also
be used to discriminate between deep and shallow conductors. Based upon simulations using multi-frequency data, it can be
concluded that such a new development would dramatically increase the resolving power of airborne VLF measurements. 相似文献
1000.