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111.
郭履灿 《CT理论与应用研究》2002,11(4):1-4
由CT理论与应用研究编辑部和北京信息工程学院主办、有中国体视学学会多位理事和会员参加的“2002年CT扫描和三维成像研讨会(CT科技学术年会)”于2002年10月18-20日,在北京大学逸夫苑理科楼学术报告厅举行。中国体视学学会副理事长刘国权教授出席致辞,对于这次CT科技年会的召开表示祝贺,并介绍了2003年在美国圣迭戈和北京将要召开第11届国际体视学会大会的有关情况,希望有关专家准备论文出席,来自全国各地48位专家,教授出席了会议,本次会议涉及CT理论、计算方法和软件及硬件技术;医学CT扫描成像和疾病诊断;工业CT和三维成像:地球层析和工程CT。美国爱荷华大学王革教授,纽约罗彻斯特大学宁若拉教授专程到会,分别做了精彩的特邀主题报告:显微CT的锥束重建新方法和近年来在这方面的进展和展望”,“锥光束三维CT技术在美国的过去、现在和未来”“国内专家也报告了前沿研究的新成果,在会前,CT理论与应用研究编辑部,根据收到的论文和摘要汇编和印制了专集,在会议最后一天,召开了“CT理论与应用研究”期刊编委会,传达了中国科协对于办好科技期刊的新要求,会议开得很成功。 相似文献
112.
中国西南及邻区上地幔P波三维速度结构/ 总被引:8,自引:0,他引:8
利用ISC报告以及中国和NEIC基本测震台网报告中的80974条P波初至到时资料(地震数为7053,台站数为165,且地震和台站都分布在研究区内),对中国西南及邻区(北纬10~36、东经70~110)的深至400km的上地幔三维速度结构进行了研究,分辨率达22.初步结果表明:①研究区速度的横向不均匀性,虽随深度增加而减弱,但至400km深度时仍很明显;②在北纬16和24的纵剖面上,可以看到与印度板块向东和欧亚板块相碰撞挤压相对应的速度结构,以及印度板块与欧亚板块速度结构的差异.在东经90的纵剖面上,与印度板块向北俯冲到欧亚板块(青藏高原)之下相对应的速度结构也比较明显;③在90km深度的横剖面上,由缅甸的密支那至越南的洞海的低速条带,可能与红河断裂带有关;④ 提出并使用了能够更为准确直观地描述分辨率好坏的图示方法. 相似文献
113.
Masao Komazawa Hitoshi Morikawa Kajuro Nakamura Junpei Akamatsu Keiichi Nishimura Sumio Sawada Ayfer Erken Akin Onalp 《Soil Dynamics and Earthquake Engineering》2002,22(9-12):829-836
The 1999 Kocaeli earthquake brought serious damage to downtown of Adapazari. To study why strong motions were generated at the town, a bedrock structure was investigated on the basis of Bouguer gravity anomaly, and SPAC and H/V analyses of microseisms. It was revealed that, the basin consists of three narrow depressions of bedrock with very steep edges, extending in E–W or NE–SW directions along the North Anatolia faults, and the depth to bedrock reaches 1000 m or more. Downtown of Adapazari is located 1–2 km apart from the basin-edge. It is considered that, the specific configuration of bedrock amplifies ground motions at the downtown area by focusing of seismic waves and/or interference between incident S-waves and surface-waves secondarily generated at the basin-edge. Studying 3D bedrock structure is an urgent issue for microzoning an urban area in a sedimentary basin. 相似文献
114.
Pierre Hudon In-Ho Jung Don R. Baker 《Physics of the Earth and Planetary Interiors》2002,130(3-4):159-174
Melting relations of β-quartz were experimentally determined at 1.0 GPa (1900±20 °C), 1.5 GPa (2033±20 °C), and 2.0 GPa (2145±20 °C) using a new high-pressure assembly in a piston–cylinder apparatus and substantial differences were found with data previously reported. The new melting data of β-quartz were combined and optimized with all available thermodynamic, volumetric, and phase equilibria data for β-cristobalite, β-quartz and coesite to produce a P–T liquidus diagram for silica valid up to 6.0 GPa. Using the new optimized thermodynamic parameters, the invariant point β-cristobalite+β-quartz+liquid and β-quartz+coesite+liquid were determined to lie at 1687±17 °C and 0.457 GPa, and 2425±25 °C and 5.00 GPa, respectively. 相似文献
115.
Chen Po-fang 《地震学报(英文版)》2002,15(5):519-525
To improve the accuracy of the numerical evaluation through the 3-D finite difference method, the surface boundary conditions
are added to modify the old program. The author has tested the new program by making calculations for the model constructed
by Wanamaker, et al (1984). The comparison between the numerical results obtained from this paper and those by Wannamaker, et al (1984) indicates that a pronounced improvement is realized in the evaluation of the horizontal magnetic components. Moreover,
better calculations for the vertical magnetic components are also obtainable by using the new program. 相似文献
116.
117.
Fe‐rich metapelitic granulites of the Musgrave Block, central Australia, contain several symplectic and coronal reaction textures that post‐date a peak S2 metamorphic assemblage involving garnet, sillimanite, spinel, ilmenite, K‐feldspar and quartz. The earliest reaction textures involve spinel‐ and quartz‐bearing symplectites that enclose garnet and to a lesser extent sillimanite. The symplectic spinel and quartz are in places separated by later garnet and/or sillimanite coronas. The metamorphic effects of a later, D3, event are restricted to zones of moderate to high strain where a metamorphic assemblage of garnet, sillimanite, K‐feldspar, magnetite, ilmenite, quartz and biotite is preserved. Quantitative mineral equilibria calculations in the system K2O–FeO–MgO–Al2O3–SiO2–H2O–TiO2–Fe2O3 (KFMASHTO) using Thermocalc 3.0 and the accompanying internally consistent dataset provide important constraints on the influence of TiO2 and Fe2O3 on biotite‐bearing and spinel‐bearing equilibria, respectively. Biotite‐bearing equilibria are shifted to higher temperatures and spinel‐bearing equilibria to higher pressures and lower temperatures in comparison to the equivalent equilibria in K2O–FeO–MgO–Al2O3–SiO2–H2O (KFMASH). The sequence of reaction textures involving spinel is consistent with a D2 P–T path that involved a small amount of decompression followed predominantly by cooling within a single mineral assemblage stability field. Thus, the reaction textures reflect changes in modal proportions within an equilibrium assemblage rather than the crossing of a univariant reaction. The D3 metamorphic assemblage is consistent with lower temperatures than those inferred for D2. 相似文献
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