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191.
通过国情普查试点工作,总结经验、工作方法,为下一步国情普查和省情普查打下良好的基础,对具体工作具有指导意义。 相似文献
192.
污染物质在地下含水介质中的运移,除受渗透系数等水文地质条件的制约外,还受到含水介质弥散系数的控制。污染物的扩散,首先是从包气带开始进行的,浑河冲洪积扇地包气带主要岩性是亚粘土及亚砂土,因此,计算出浑河冲洪积扇包气带的弥散系数,对于认识污染物的运移能力是一项必要的工作。本文利用室内动态土柱装置,模拟包气带岩性环境,以0.05 mol/L的NaCl溶液作为示踪剂,经长时间监测,运用弥散系数计算公式进行求参。计算结果是包气带以亚粘土为主要岩性的弥散系数为0.005 71 m2/d,亚砂土的弥散系数为0.012 47 m2/d。 相似文献
193.
黔西北地区地下水赋存规律及开发利用方向 总被引:1,自引:1,他引:0
黔西北地区地处乌蒙山区岩溶发育强烈,地下水系统小型多样、条件复杂,地下勘查找水及开发利用难度大。本文通过对三种不同岩溶流域类型区地下水赋存规律及岩溶发育的综合研究,提出了不同类型系统中勘查找水和开发利用的方向建议,对该类区中地下水资源勘查找水和开发利用工作有一定的指导意义。 相似文献
194.
This study presents a review of recently recorded instability phenomena on the flysch slopes of Istria, Croatia. The northeastern part of the Istrian Peninsula, the so-called Gray Istria, is built of Paleogene flysch deposits, where instability phenomena are frequent and where a large number of landslides, with significant consequences, have been recorded over the past 35 years. Based on field investigations conducted for the purpose of remedial study design, a database of these landslides was created. An investigation of the documented landslides and their elements found some common features that enabled general conclusions about the conditions and causes of landslide occurrence. In total, 19 documented landslides have been analyzed as individual phenomena, and from the results of these analyses, general conclusions were drawn about sliding conditions and the main triggering factors. Geological conditions and processes on slopes where landslides occurred are shown in detail, and geotechnical properties have been systematically represented. The sliding conditions and dimensions of four recent landslide occurrences, specifically by type, have been described in detail and analyzed. 相似文献
195.
Cüneyt Akal Osman Candan O. Ersin Koralay Roland Oberhänsli Fukun Chen Dejan Prelević 《International Journal of Earth Sciences》2012,101(1):177-194
Afyon Zone, which was derived from the Anatolide–Tauride platform during closure of the Neo-Tethys, is made up of pre-Mesozoic
basement and unconformably overlying Triassic–Early Tertiary cover series. The Afyon Zone contains widespread metavolcanic
rocks, which are dominated by rhyolite, dacite, and trachyandesite. They form a distinct volcanic succession, which is separated
from the underlying Silurian–Lower Carboniferous metacarbonates and meta-siliciclastics by a regional unconformity. Trachyandesitic
metavolcanics are made up of massive lava flows, pyroclastics and epiclastics, less frequently, domes and dikes, which were
developed on a deeply eroded subaerial landmass. U/Pb and Pb/Pb zircon geochronology yielded Lower Triassic (~250 Ma) ages,
which are interpreted as extrusion age of trachyandesitic volcanics. Based on the stratigraphic, geochronological, and geochemical
data, we suggest that these Lower Triassic magmatic rocks represent an extensional tectonic setting on the northern active
margin of the Gondwana, which led to the development of the northern branch of the Neo-Tethys. 相似文献
196.
Eugen Vujić Giuliana Verbanac Stanislav Francisković-Bilinski Vladis Vujnović Antun Marki 《Studia Geophysica et Geodaetica》2011,55(1):175-190
Based on the ground survey of total-field magnetic data at 53 sites, which recorded a time-series over the interval 2003–2005,
the core field + long wavelength lithospheric field over the middle-northern Croatia region was calculated. The area of the
survey was 18900 km2, an average distance between the neighbouring sites being 12 km. The results were reduced to 2004.5 epoch. This “normal”
total-field was estimated using the firstorder Taylor polynomial as a function of geographic coordinates, and the polynomial
coefficients were calculated with three methods of adjustment: simple and weighted least squares fits and adjustment according
to the most frequent value. The stability of the normal field was tested using the Monte Carlo-type test, by decreasing the
input data set in each adjustment (up to 90%). All obtained field residuals (measured-“normal”) were mutually compared, as
well as fit coefficients of the Taylor polynomials. The residual values indicate the presence of shorter-wavelength anomalies,
specifically three major residual anomalies were found (−106 nT, 74 nT and 57 nT). The geostatistical analysis of the ground
survey data and the normal field residuals (respectively), using the median absolute deviation method, was further conducted
in order to evaluate the calculated anomalies. The geological situation around the anomalies derived by the median absolute
deviation method, and around the normal field residual anomalies, is given. The correlation was found between higher value
anomalies of the normal field residuals, and shallow volcanic rocks and oil field, respectively. 相似文献
197.
在复杂地质条件下进行钻探或处理事故时,常有需要增加钻压的情况。而所选钻机其所能产生的轴向压力是一定的。因此,在钻机选定后如何增加钻压的问题是个非常重要的问题,有时是一个非常急迫的问题。乌克兰国立矿业大学的专家们利用水力动力学原理研制出了一种新型钻压水动力增效装置,可以解决上述问题,值得借鉴。介绍了这种钻压水动力增效装置(ГУОН)的工作原理及其技术性能指标,并通过试验结果与理论计算结果进行了对比。 相似文献
198.
A. Šajnović K. Stojanović V. Simić G. S. Pevneva A. K. Golovko B. Jovančiećević 《Geochemistry International》2011,49(10):1022-1034
Liquid thermolysis products of various types of immature kerogen from sedimentary lacustrine rocks from the Valjevo-Mionica
basin in Serbia were studied to evaluate the generation potential of kerogen contained in the organic matter (OM) of the rocks,
determine the composition of the biomarkers and alkylaromatics in the liquid thermolysis products, and elucidate the effect
of Pt4+ and Ru3+ ions (which were added in the form of inorganic salts) on the yield and hydrocarbon composition of the liquid thermolysis
products. For this purpose, representative bitumen-free samples A and B of the sedimentary rocks were subjected to thermolysis
under various conditions. Rock A contains high amount of immature organic matter, which is dominated by kerogen type I/II
and was generated under strongly reduced sedimentation conditions at a high salinity. Sample B is poorer in immature OM than
sample A, and the OM of the former contains kerogen type II/III and was generated predominantly in a reduced environment.
The content of the liquid products and the concentrations of hydrocarbons obtained in the course of thermolysis of bitumen-free
sample A and the typical oil distribution of the biomarkers and alkylaromatics in the thermolysis products confirm a high
generation potential of OM in this rock. In all of our experiments on the thermolysis of bitumen-free sample B, the yield
of liquid products and hydrocarbons is low. According to the kerogen type, the thermolysis of this rock generates much gases.
The Pt4+ and Ru3+ ions (added in the form of simple inorganic salts) increased the yield of liquid (kerogen type I/II) and gaseous (kerogen
type II/III) products. During the thermolysis of various type of immature kerogen in the lacustrine sedimentary rocks at a
temperature of 400°C, the OM attained maturation corresponding to the early catagenesis level. Saturated biomarkers and alkylaomatics
in the thermolysis products of both samples display typical oil distributions. The type of the source OM most strongly affects
the composition of n-alkanes and alkylnaphthalenes. The metal ions used in this research served as catalysts for the methylation process during
the thermolysis of immature kerogen, regardless of its type. The effect of the Pt4+ and Ru3+ ions on other transformations of the hydrocarbons, for example, the destruction of high-molecular n-alkanes to low-molecular ones and on isomerization reactions in molecules of polycyclic biomarkers and alkylaromatics to
thermodynamically more stable isomers in the thermolysis products is controlled, first of all, by the type of the source OM. 相似文献
199.
200.
诸多迹象表明,敖市金刚石异常为一浓集异常,且叠加在一辉石重砂异常之上,显示出强烈的近源补给特征,其补给源极有可能是具工业价值的金刚石原生矿.鉴于湘黔金刚石成矿区内已知的含金刚石钾镁煌斑岩及其相关岩体的同位素年龄值均在375~475 Ma范围,其成矿期显然属加里东晚期,而紧邻敖市异常尚有后加里东盖层残留,作为幔源火山作用... 相似文献