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91.
92.
塔里木盆地库车河烧变岩的形成年龄 总被引:2,自引:0,他引:2
用K-Ar测年技术确定了塔里木盆地库车河剖面上二叠统二次侵入岩的形成年龄为227.6±3.34Ma,还使用ESR技术测试了侵入岩和烧变岩中石英氧空位的相对浓度。根据库车河二次侵入岩的K-Ar年龄,石英氧空位的相对浓度和剂量率,估算出上三叠统塔里齐克组烧变岩的形成年龄为3.26±0.3Ma,中侏罗统克孜努尔组烧变岩的形成年龄为2.33±0.2Ma。此外,还讨论了烧变岩形成年龄的可靠性问题。 相似文献
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<正>Foreland basin represents one of the most important hydrocarbon habitats in central and western China.To distinguish these foreland basins regionally,and according to the need of petroleum exploration and favorable exploration areas,the foreland basins in central and western China can be divided into three structural types:superimposed,retrogressive and reformative foreland basin(or thrust belt),each with distinctive petroleum system characteristics in their petroleum system components(such as the source rock,reservoir rock,caprock,time of oil and gas accumulation,the remolding of oil/gas reservoir after accumulation,and the favorable exploration area,etc.).The superimposed type foreland basins,as exemplified by the Kuqa Depression of the Tarim Basin, characterized by two stages of early and late foreland basin development,typically contain at least two hydrocarbon source beds,one deposited in the early foreland development and another in the later fault-trough lake stage.Hydrocarbon accumulations in this type of foreland basin often occur in multiple stages of the basin development,though most of the highly productive pools were formed during the late stage of hydrocarbon migration and entrapment(Himalayan period).This is in sharp contrast to the retrogressive foreland basins(only developing foreland basin during the Permian to Triassic) such as the western Sichuan Basin,where prolific hydrocarbon source rocks are associated with sediments deposited during the early stages of the foreland basin development.As a result, hydrocarbon accumulations in retrogressive foreland basins occur mainly in the early stage of basin evolution.The reformative foreland basins(only developing foreland basin during the Himalayan period) such as the northern Qaidam Basin,in contrast,contain organic-rich,lacustrine so urce rocks deposited only in fault-trough lake basins occurring prior to the reformative foreland development during the late Cenozoic,with hydrocarbon accumulations taking place relatively late(Himalayan period).Therefore,the ultimate hydrocarbon potentials in the three types of foreland basins are largely determined by the extent of spatial and temporal matching among the thrust belts,hydrocarbon source kitchens,and regional and local caprocks. 相似文献
95.
SONG Yan ZHAO Mengjun HONG Feng LIU Shaobo QIN Shengfei WANG Hongyan 《《地质学报》英文版》2010,84(6):1539-1546
<正>The pool-forming mechanism of coalbed methane has its own characteristics.In this paper, based on studies on the typical coal-bearing basins in China,it is pointed out that the reservoir formation of medium- to high-rank coalbed methane has experienced three critical stages:the coalbed methane generation and adsorption stage,the coalbed adsorption capacity enhancement stage,and the coalbed methane desorption-diffusion and preservation stage.The regional tectonic evolution, hydrodynamic conditions and sealing conditions play important roles in the stage of coalbed methane desorption-diffusion and preservation.Medium- to high-rank coalbed methane has three types of enrichment models,that is,the most favorable,the relatively favorable,and the unfavorable enrichment models. 相似文献
96.
针对目前结构行波效应研究现状,文中借助建筑结构通用有限元软件Midas/Gen,采用一致与非一致2种激励方式对长度为33~264m的3层钢筋混凝土框架结构进行弹性时程分析.通过对比一致与非一致激励下的柱弯矩,剪力以及轴力,详细讨论其随波速、长度以及不同部位的变化规律.结果表明:柱内力都遵循波速越慢,结构长度越长,行波效应越明显.框架柱弯矩第1层与2、3层差异比较大,增大的柱主要集中在结构第1层两端,1层中部和2,3层的柱均表现为减小;剪力与弯矩有相似的变化规律,只存在量上的差别,正负剪力与弯矩分别最大差异只有4.4%,-4.5%;波速、长度的改变对柱轴力的影响有限,变化幅度不超过2.7%. 相似文献
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98.
In this paper, we propose an efficient scheme for extracting the complex bottom reflection coefficient (phase and amplitude) in a shallow water waveguide by using the WKB modal condition. The input data are the measured modal wavenumber (km) and the modal attenuation (βm). The main advantages of this scheme are: 1) it is efficient, because there are no replica calculations as in the conventional matched field processing (MFP) scheme, 2) the inverted error induced by the “noise” of the contaminated data can be estimated analytically, and 3) the impact of the environmental (SSP) mismatch can also be estimated analytically. Numerical simulations illustrate that the proposed scheme works well in different scenarios of shallow water waveguides 相似文献
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揭示高铁对中国航空客运市场影响的空间分异特征,对于针对性协调2种交通方式的发展具有重要参考价值。运用标准差椭圆和交通综合效用分析方法,对中国中心城市高铁、航空客运市场实际发展现状及空间竞合分异特征进行分析。结果发现:① 高铁、航空客运市场均形成以武汉为重心点的空间发展格局;与高铁客运市场相比,航空客运市场区域发展更加均衡;与东西部中心城市相比,中部中心城市旅客出行选乘高铁的概率更高。② 人均时间价值与高铁优势距呈反比,优势距的不同使各中心城市高铁、航空客运市场范围存在明显的空间分异特征;基于交通出行综合效用视角,中国大多数中心城市间的交往,航空出行依旧是最好的选择。③ 高铁对航空客运市场的影响存在明显的空间分异特征。中部大部分中心城市受影响最大,是协调高铁、航空发展的关键区域;西部地区受交通区位条件及高铁发展滞后的影响,中心城市间交往时飞机仍是旅客主要的出行方式,在航空主导优势区依旧存在一定的市场空白。 相似文献