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101.
成矿流体中碲逸度对自然金成色的影响   总被引:1,自引:0,他引:1  
富碲化物型金矿具有自然金成色高的特点,通过热力学分析,推导出碲逸度与温度和自然金中银含量的关系式,建立了fTe2-T-NAg图解,并论述了该类型金矿中高自然金成色的内在原因,即成矿溶液中高的碲逸度导致了高的自然金成色,同时也分析了溶液中碲逸度对金银矿物的共生组合的影响,以及对如何计算成矿溶液中碲逸度问题进行了讨论。  相似文献   
102.
针对高空间分辨率多光谱图像,设计了一种基于缨帽变换、数据正则化以及多尺度光谱分析技术的多尺度循环检测算法。实验结果表明:对于Landsat-7 ETM+图像,其检测精度与基于热波段的自动化云量估计算法相近,但优于传统的直接分类方法(最大似然分类与ISODATA分类)。由于该算法无需借助热波段及其他辅助数据,因而在实现高分辨率图像厚云掩膜的高效与高精度提取方面具有很高的应用潜力。  相似文献   
103.
The behavior of a self-supported earth-retaining wall with stabilizing piles was investigated using a numerical study and field tests in urban excavations. Special attention is given to the reduction of lateral earth pressures acting on a retaining wall with stabilizing piles. Field tests at two sites were performed to verify the performance of the instrumented retaining wall with stabilizing piles. A number of 3D numerical analyses were carried out on the self-supported earth-retaining wall with stabilizing piles to assess the results stemming from wide variations of influencing parameters such as the soil condition, the pile spacing, the distance between the front pile and the rear pile, and the embedded depth. Based on the results of the parametric study, the maximum horizontal displacement and the maximum bending moment are significantly decreased when the retaining wall with stabilizing piles is used. In engineering practice, reducing the pile spacing and increasing the distance between the front pile and the rear pile can effectively improve the stability of the self-supported earth-retaining wall with stabilizing piles.  相似文献   
104.
深海半潜浮式生产平台FPU(floating production unit)是国际海洋油气资源开发的关键基础性装备。针对半潜浮式生产平台的技术特点,系统阐述其各方面特性(包括:总布置、系泊和立管、水动力性能、结构设计与分析等)及相关研究现状和未来发展趋势。并结合我国南海地理、水文和资源环境等特点,对未来半潜浮式生产平台的开发提出了一些建议。  相似文献   
105.
通过回归分析,得出养殖斑节对虾Penaeus monodon Fabricius体长(L)与体重(W)的关系为W=aL~b。根据此公式,计算得出体长和体重换算表,这在养殖生产中有现实意义。  相似文献   
106.
107.
直立椭圆柱体重力场的谱分析及其应用   总被引:1,自引:0,他引:1  
范守志 《海洋与湖沼》1995,26(3):234-240
利用傅里叶积分变换法导出了埋藏的直立椭圆柱体的重力场在频率域中的解析公式,依此得了确定此直立椭圆柱体尺寸的公式,提出依据这些重力公式来计算侵入大洋地壳中的地幔柱的尺寸和洋壳厚度的方法。  相似文献   
108.
Based on the test data in dynamic water and static water, the main factors, which influence the fine sediment flocculation, are analyzed with a gray model method of correlation theory. It is shown that the main influencing factors are water temperature, settling time, salinity, grain size, sediment concentration and current velocity according to the correlation coefficients. Among them, the salinity and the sediment grain size are critical type influencing factors (CrTIF); the settling time, the sediment concentration and the velocity are continuous type influencing factors (CoTIF); and the water temperature has the characteristics of both. When the critical values of CrTIF are reached or exceeded, the fine sediments will be flocculated, but values of CrTIF will not influence the settlement strength of floes. The influence of CoTIF is continuous. The values of the CoTIF will not only influence the occurrence of flocculation but also the settlement strength of the floes.  相似文献   
109.
Natural soils are one of the most inherently variables in the ground. Although the significance of inherent soil variability in relation to reliable predictions of consolidation rates of soil deposits has long been realized, there have been few studies that addressed the issue of soil variability for the problem of ground improvement by prefabricated vertical drains. Despite showing valuable insights into the impact of soil spatial variability on soil consolidation by prefabricated vertical drains, available stochastic works on this subject are based on a single‐drain (or unit cell) analyses. However, how the idealized unit cell solution can be a supplement to the complex multi‐drain systems for spatially variable soils has never been addressed in the literature. In this study, a rigorous stochastic finite elements modeling approach that allows the true nature of soil spatial variability to be considered in a reliable and quantifiable manner, both for the single‐drain and multi‐drain systems, is presented. The feasibility of performing an analysis based on the unit cell concept as compared with the multi‐drain analysis is assessed in a probabilistic context. It is shown that with proper input statistics representative of a particular domain of interest, both the single‐drain and multi‐drain analyses yield almost identical results. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   
110.
Chlorite and associated minerals from the volcanogenic Taveyanne metasediment of the western Helvetic nappes, Switzerland, were investigated by electron microprobe (EMP) and transmission electron microscopy (TEM) in order to determine their textural and chemical evolution during low-temperature metamorphism. EMP analyses of chloritic material from sub-greenschist facies outcrops show a decrease of Si and Σ(Ca, Na, K) with increasing metamorphic grade. A number of conclusions may be drawn from combined TEM images and analytical electron microscopy (AEM) data. 1 In diagenetic-grade samples, chlorite crystals (observed maximum defect-free distance=80 nm) always contain some 1 nm layers (with a maximum of 29% of all layers) and less frequently some 0.7 nm berthierine-like layers. With increasing grade, the amounts of 1 and 0.7 nm layers decrease, and most chlorite from the epizone is structurally pure or contains less than 2% of 1 nm layers. 2 A positive correlation was found between the amount of 1 nm layers and the Ca+K+Na content, indicating that the 1 nm layers are saponite. 3 Observations and calculations suggest that the transformation reaction of saponite to chlorite takes place by the replacement of the interlayer cations in saponite by brucite-like layers resulting in a local volume decrease. In contrast, the destruction of berthierine has only minor influence on the local bulk volume. These results confirm recent studies which show that the change in composition measured by EMP of diagenetic-grade chloritic material are mainly the result of mixtures of chlorite and saponite. The use of chlorite ‘geothermometry’ in such systems is greatly influenced by the presence of saponite and hence is not based on reaction equilibria, even though temperatures calculated in this study agree with temperatures derived from other methods. Therefore, chlorite evolution should be treated as a kinetically controlled grade indicator and developed as a qualitative scale similar to the illite crystallinity index.  相似文献   
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