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111.
中尺度数值模式的资料同化系统:(一)伴随模式的设计 总被引:7,自引:4,他引:3
以一个有限区域的中尺度模式为基础,采用伴随模式技术进行有限区域气象资料的同化。伴随模式的方法是以数值天气预报的动力模式作为约束条件的变分方法,比传统的变分方法有了很大的改进。本文初步探讨了伴随模式系统的设计方法,特别是伴随模式的构造问题;用共轭码地方法导出伴随模式;初步试验表明该系统有较强的同化能力。 相似文献
112.
Liu Xianwen Meng Xiangang Institute of Geomechanics Chinese Academy of Geological Sciences Beijing Tamaki Kensaku Ocean Research Institute University of Tokyo Tokyo Japan Shen Ninghua Ge Xiaohong Department of Earth Sciences Cha 《中国地质大学学报(英文版)》1998,9(3)
INTRODUCTIONTheNortheastChinaanditsadjacentregionpresentauniquetectonicpatern,whichisdistinguishedbylargescaleNEtrendinggrani... 相似文献
113.
中国科学院紫金山天文台青岛观象台从1996年4月开始到1995年5月1日结束,在138个观测夜,共拍摄Hale-Bopp彗星底片508张。发现:Hale-Bopp彗星在1996年9月24日的一次爆发,1996年10月26日,11月13日的两次可能爆发。在1996年9月23日的底片上,Hale-Bopp呈现巨大的喷流。在1997年2月8日至5月1日期间,Hale-Bopp彗星彗头内存在大量壳层结构。 相似文献
114.
Bian Lizeng Lin Chengyi Zhang Fusheng Du De''an Chen Jianlin Shen Huadi Department of Earth Sciences Centre for Materiale Analysis Nanjing University Jiangsu Second Institute of Oceanography State Oceanic Administration Hangzhou Zhejiang Liu Xinzhu 《《地质学报》英文版》1997,71(1):43-48
Pelagic manganese nodules from the East Pacific Ocean have been studied using polarizing,scanning electron and transmission electron microscopes. It has been revealed that the manganesenodules are composed of cores and stromatolite coatings. The structures and textures of thesenodules are peculiar to oncolite. Consequently, the pelagic manganese nodules are manganeseoncolites. Based on the stromatolites in the coatings, the manganese oncolites from the East Paci-fic Ocean can be divided into two types. One is smooth on surface and dense inside. Its coatingsare composed mainly of Minima. The other has a knobby surface and is loose internally. Itscoatings consist mainly of Admirabilis. The TEM investigation has also revealed that the con-structors of the manganese oncolites are ultra-microbes. The Minima is constructed byMiniactinomyces chinensis sp. nov. and the Admirabilis is built by Spirisosphaerospora pacifica sp.nov. 相似文献
115.
地质环境及其功能的控制与开发 总被引:4,自引:0,他引:4
地质环境是天然环境的一个组成部分,是人类居住和赖以生存的浅部地质空间。地质环境具有如下特征:空间性,其上限为地表,其下限视研究目的而定;稳定性,其环境要素是相对。稳定的;可变性,地质作用及人类活动可能改变局部地质环境;系统性,地质环境是一个由生物因素和非生物因素组成的环境系统,该系统本身具有恢复调节功能。地质环境的环境功能是指它对人类居住环境质量的影响。其影响有两种,一是使环境质量恶化的影响,是一种不良的功能;一是使环境质量得以保护和改善的影响,是一种良性功能。地质环境是环境工程的一种,是控制不良地质环境功能和开发良性地质环境功能的环境工程。地质环境工程是环境地质研究的一个新思路。地质环境工程包括有:地下水环境工程、控制不良地质环境的地质环境工程、净化废物的地质环境工程、贮存废物的地质环境工程、特殊地质环境的开发和利用。 相似文献
116.
Isotope Geochemical Characteristics and Material Sources of Tin--Bearing Porphyries in South China 总被引:3,自引:0,他引:3
Shen Weizhou Wang Dezi Liu Changshi Department of Earth Sciences Nanjng University Nanjng Jiangsu 《《地质学报》英文版》1996,70(2):181-192
Tin-bearing porphyries in South China can be divided into the F-rich and F-poorsubtypes. They are high-silica (SiO_2>71%), peraluminous (A/NKC>1.0) and rich inincompatible elements (Rb, Zr, U, W, Sn) and have weak Ce (δCe=0.68-0.82) and strong Eu(δEu=0.01-0.38) negative anomalies. Meantime, they also have low δ_(Nd)(-6.3- -8.4), high~(207)Pb/~(204)Pb (15.588-15.790), medium to high (~(87)Sr/~(86)Sr)_i (0.7084-0.7287) and relatively highδ~(18)O(9.1-10.3‰). These characteristics clearly suggest that the two subtypes of tin-bearingporphyries were derived from the crustal materials. Their differences lie only in the existence ofcertain different components in their source materials. Therefore, there is only one type oftin-bearing prophyry in South China. that is continental crust transformation type. 相似文献
117.
Based on the dynamic and thermodynamic equations in the SBL,the protection characteristics and mech-anism of shelterbelts are numerically studied in this paper.The results are in consistent with those ob-served in fields and wind-tunnels.Research shows that the belts with a permeability of 0.3—0.4 have themaximum sheltering effects.The distance where wind speed reduces at least by 20% is at 18—19 times oftree height(H)behind belts.The protection distance reduces fast with the increase of the permeability andslowly with its decrease.The belts have weaker sheltering effects in upstream,generally beyond 6H infront of belts there are no sheltering effects.In addition,the belts with low permeability at top and highpermeability at bottom have much better sheltering effects than the belts with high permeability at top andlow permeability at bottom.The belts with 50% overall permeability reduce wind speed at least,by 20%at the distance of 5H on the leeward side and by 10% at 11H.When the air is unstable,the protectingeffects will be reduced.For the uniform belts with a permeability of 0.35,the distance where wind speedreduces at least by 20% is 15H under the unstable air and 13H under very unstable air.The belts reducethe turbulent diffusion coefficient at the bottom of belts,but increase it at the top. 相似文献
118.
In this paper, the dynamic disturbances to various basic zonal currents caused by the Tibetan Plateau are simulated by means of a three-level primitive equation model, in which σ is used as the vertical coor-dinate. Four types of currents have been used, i. e. the barotropic homogeneous current, barotropic jet stream, baroclinic current and the zonal mean current in summer. The results are helpful to understand the dynamic effects of the Tibetan Plateau on the general circulation over East Asia. 相似文献
119.
In this paper, four problems are discussed: (1) the monsoon circulation over southern Asia; (2) the seasonal variation of the general circulation of the atmosphere; (3) the influence of the monsoon on the rainfall in southwestern China; and (4) the source region of water vapor for the rainfall in the Changjiang valley. 相似文献
120.
Li Shengrong Key Laboratory of Lithospheric Tectonics Lithoprobing Technology China University of Geosciences Ministry of Education Beijing China Gao Zhenmin Institute of Geochemistry Chinese Academy of Sciences Guiyang China Shen Junfeng Key Laboratory of Lithospheric Tectonics Lithoprobing Technology China University of Geosciences Ministry of Education Beijing China 《中国地质大学学报(英文版)》2004,15(1):84-90
INTRODUCTIONPlatinum group element (PGE)oredepositsofmag maticliquationoriginwereidentifiedtobethemaintype ,oreventheonlytypeofPGEoredeposits .Theorebodiesoc curdirectlyintheultramafic maficigneousrocksorthecon tactzonebetweentheigneousrocksandtheirwall rocks .Theformingtemperatureofthedepositswasabout 4 0 0 - 5 0 0℃orevenhigher.Foralongtime ,therefore ,ithadbeenconsideredthattheenrichment,mineralizationandtransfer enceofPGEcouldonlyoccurinultramafic maficigneousrocksathightemperature… 相似文献