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991.
992.
STRATIGRAPHY Yao Ling (瑤林) lies 40 li southeast from Chen Hsien city (郴縣), about Long. 112°30′E., Lat. 25°40′N., and is halfway between Chen Hsien city and the well known wolfram mining district, Yao Kang Sien (瑤崗仙). On the 相似文献
993.
Early in July, 1928, Mr. H. K. Lin, the noted lawyer of Peking, approached Dr. W. H. Wong, director of the Geological Survey of China, for solution of some water supply problems, recently arisen in a tract of hilly land (of which Mr. Lin is the owner) in the eastern foot of the Mont Miao FengShan 相似文献
994.
995.
The differentiated Mesozoic alkali dolerite Prospect Intrusion contains a wide range of secondary minerals, including carbonates (primarily calcite), laumontite, prehnite and heulandite, whose stability relationships imply a formation temperature of <200°C. The δ18O data for carbonates define a higher temperature (160 – 195°C) suite, and a lower temperature (51 – 73°C) suite. The δ13C, δ18O and 87Sr/86Sr isotope systematics for these carbonates suggest derivation of the higher temperature group from magmatic fluids, whereas the other group had a major meteoric component that probably originated from porewater in the country rock. Source fluids for prehnite were meteoric rather than magmatic in origin based on their δD and δ18O ratios. Early in the intrusion's emplacement, CO2-rich hydrothermal fluids formed a carbonate rind sealing the upper part of the hydrothermal system and produced the higher temperature carbonates (calcite) and laumontite. Later, cooler fluids with a meteoric component infiltrated vesicles and fractures, depositing the lower temperature carbonates (calcite, aragonite), heulandite and prehnite. 相似文献
996.
西南天山布隆金矿床成矿作用同位素地质年代学 总被引:1,自引:2,他引:1
位于新疆西南天山阿合奇县的布隆金矿是一个国内较少见的低温热液石英重晶石脉型金矿床,它赋存于上泥盆统细碎屑岩中,金矿体受层间缓倾斜破碎带控制.根据矿脉矿物组合及相互穿插关系,原生成矿期成矿作用可分为:①黄铁矿-石英阶段;②石英-黄铁矿-菱铁矿-重晶石阶段;③方解石-石英-重晶石阶段和④重晶石阶段.年代学研究表明,主成矿阶段(②阶段)含金石英脉Rb-Sr等时线年龄为258±15 Ma,表明成矿作用发生在晚二叠世末,与中亚南天山大规模的金成矿作用发生时期相一致. 相似文献
997.
998.
This paper proposes the use of a novel type of passive vibration control system to reduce vibrations in civil engineering structures subject to base excitation. The new system is based on the inerter, a device that was initially developed for high‐performance suspensions in Formula 1 racing cars. The principal advantage of the inerter is that a high level of vibration isolation can be achieved with low amounts of added mass. This feature makes it an attractive potential alternative to traditional tuned mass dampers (TMDs). In this paper, the inerter system is modelled inside a multi‐storey building and is located on braces between adjacent storeys. Numerical results show that an excellent level of vibration reduction is achieved, potentially offering improvement over TMDs. The inerter‐based system is compared to a TMD system by using a range of base excitation inputs, including an earthquake signal, to demonstrate how the performance could potentially be improved by using an inerter instead of a TMD. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
999.
In this study a non-hydrostatic version of Penn State University (PSU) -- NationalCenter for Atmospheric Research (NCAR) mesoscale model is used to simulate thesuper cyclonic storm that crossed Orissa coast on 29 October 1999. The model isintegrated up to 123 h for producing 5-day forecast of the storm. Several importantfields including sea level pressure, horizontal wind and rainfall are compared with theverification analysis/observation to examine the performance of the model. The modelsimulated track of the cyclone is compared with the best-fit track obtained from IndiaMeteorological Department (IMD) and the track obtained from NCEP/NCAR reanalysis. The model is found to perform reasonably well in simulating the track and in particular, the intensity of the storm. 相似文献
1000.
J. V. Smith 《Australian Journal of Earth Sciences》2013,60(5):807-815
Strongly boudinaged sandstone beds in a Palaeozoic accretionary complex are exposed on Great Keppel Island, off the central Queensland coast. Viewed in profile, the boudins are folded around mesoscopic F2 hinge zones and overprinted by S2 foliation indicating formation either during Late Carboniferous subduction accretion (D1) or during a previously unrecognised discrete early phase of the Permian deformation (D2). Boudin profiles record an average stretch of 1.51, although the contribution of D2 and later deformation is not determined. Viewed in the plane of bedding, vein traces are variable and oblique to boudin necks by an average of 12° anticlockwise. The overall en echelon arrangement of veins in boudin necks is a primary feature of the structure and cannot be attributed to later deformation. This pattern of veining indicates oblique extension of the boudin necks by low‐vorticity non‐coaxial flow within the plane of bedding. One possible setting with such kinematics is the limb of a non‐cylindrical fold. 相似文献