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321.
微细浸染型(卡林型)金矿成矿过程中碳和有机质的作用 总被引:10,自引:2,他引:10
在众多关于黔滇桂微细浸染型(卡林型)金矿研究成果的基础上,本文通过本类型金矿含碳及有机质的特征;金能形成金属有机化合物及原子簇化合物的特征的研究。提出金以金属有机化合物形式在本区上二叠统富含生物成因有机质的煤系地层中形成预富集;在区域热变质作用中,金以气相金属有机化合物方式向上运移,蓄积在上二叠统至中三叠统各层位的背斜和穹隆部位;动力变质带的断裂活动引起物理化学突变,使金的气相金属有机化合物在构造断裂带解体、裂化从而形成了含细分散碳质的微细浸染型含金硫化物原生矿化;并探讨了主成矿期后与有机质解体有关的叠加热液活动和表生氧化作用对原生矿化的改造。从而从有机质演化角度初步建立了此类型的成矿模式 相似文献
322.
Extensive functional group analyses were performed on humic acids representative of eight increasing depth levels from a core drilled in the Mahakam delta (East Kalimantan, Indonesia). Oxygen amounts decrease observed during early diagenesis was related chiefly to loss of hydroxyl (lignol?) groups. Comparison between upper and deeper levels shows the following variations: hydroxyl group abundances go from 19 to 6% of humic oxygen. Identified functional groups amounts represent 47 to 32% of weight of moisture- and ash-free humic acids. No evidence of decarboxylation of humic material was detected. 相似文献
323.
Rheological Properties of Partially Molten Lherzolite 总被引:2,自引:1,他引:2
Lherzolite samples synthesized from fine-grained powders preparedfrom a natural xenolith were deformed at P = 300 MPa and 1373 相似文献
324.
The hypoplastic constitutive model is known for its numerous application to the problems of soil mechanics and also for its excessive ratcheting. The paper shows that this deficiency can be interpreted as Liapunov instability in dynamic case. This is demonstrated with a simple one-dimensional swinger. Infinitesimally small as well as finite oscillations are analytically examined and the variability of stiffness upon a single cycle is considered. Several methods to circumvent the problem of ratcheting are discussed: implementation of ‘elastic’ range by means of so-called intergranular strain, usage of overlay modelling with parallel coupling of hypoplastic materials as originally proposed by Valanis in his endochronic theory and a special coupling of hypoplastic models based on comparison of partial stiffnesses. 相似文献
325.
326.
Sonia Tonarini Maddalena Pennisi Alessandra Adorni-Braccesi rea Dini Giorgio Ferrara Roberto Gonfiantini Michael Wiedenbeck Manfred Gröning 《Geostandards and Geoanalytical Research》2003,27(1):21-39
In 1999 the Istituto di Geoscienze e Georisorse (IGG), with the support of the International Atomic Energy Agency (IAEA), undertook the collection, preparation and distribution of eight geological materials intended for a blind interlaboratory comparison of measurements of boron isotopic composition and concentration. The materials came from Italian sources and consist of three natural waters (Mediterranean seawater and two groundwaters) and five rocks and minerals (tourmaline, basalt, obsidian, limestone and clay). The solid materials were crushed, milled and mixed, in preparation for distribution. Extensive assays performed at the IGG on these materials demonstrated that their boron isotopic and chemical compositions are homogeneous.
Additional homogeneity tests were carried out on solid material fragments at the GeoForschungsZentrum Potsdam, with the specific objective of investigating the suitability of some of them for the calibration in situ of micro-analytical techniques. Two materials, B4 (tourmaline) and B6 (obsidian), proved to be isotopically homogeneous and may become excellent references for in situ microanalyses of boron isotopes.
The materials described here were used as the basis of a major laboratory intercomparison study and are now available for further distribution from either the IAEA (solid materials) or the IGG (waters). 相似文献
Additional homogeneity tests were carried out on solid material fragments at the GeoForschungsZentrum Potsdam, with the specific objective of investigating the suitability of some of them for the calibration in situ of micro-analytical techniques. Two materials, B4 (tourmaline) and B6 (obsidian), proved to be isotopically homogeneous and may become excellent references for in situ microanalyses of boron isotopes.
The materials described here were used as the basis of a major laboratory intercomparison study and are now available for further distribution from either the IAEA (solid materials) or the IGG (waters). 相似文献
327.
Tiexin Gu Wei Bu Weidong Yan Changyi Shi Mingcai Yan 《Geostandards and Geoanalytical Research》2003,27(2):193-196
Sulfide mineral certified reference materials GSO 1-7, recently prepared by the Institute of Geophysical and Geochemical Exploration (IGGE), were analysed by twelve laboratories. Various reliable analytical methods based on different principles were adopted and classical chemical methods were taken as the primary analytical methods, by which 5729 determinations were carried out, 1425 average data were obtained, and twenty one to twenty seven elements and components were certified. 相似文献
328.
岩石相似材料摩擦实验装置的改进 总被引:1,自引:1,他引:1
在岩石相似材料模型试验中,摩擦实验是必不可少的实验,它用来确定节理、裂隙、滑动面等软弱结构面相似材料的抗剪强度参数。本文介绍了一种改进的摩擦实验装置,实验表明采用该装置获得的实验数据更加准确、可靠,同时,还可以利用该装置确定岩石结构面的抗剪参数。 相似文献
329.
采用底泥掩蔽技术,选取天然红土,添加适量的粉煤灰及石灰粉作为掩蔽覆盖物,对滇池富营养化水体进行现场修复实验。结果表明:用天然矿物材料减小底泥内源营养盐负荷的释放修复富营养化水体的效果良好;红土是有效的底泥覆盖材料,添加粉煤灰和石灰粉有助于消减底泥中TP、TN的释放量,还可提高对藻类等浮游植物繁殖的营养基础和对藻、藻细胞及其胚胎上浮生长的控制效率,最终达到除藻的目的,为滇池及类似湖库富营养化水体的修复提供了崭新的思路。 相似文献
330.
Akio Makishima Katsura Kobayashi Eizo Nakamura 《Geostandards and Geoanalytical Research》2002,26(1):41-51
A simple and accurate method for the determination of Cr, Ni, Cu and Zn at μg g?1 levels in milligram‐sized bulk silicate materials is reported using isotope dilution high‐resolution inductively coupled plasma‐mass spectrometry (HR‐ICP‐MS) with a flow injection system. Silicate samples with Cr, Ni, Cu and Zn spikes were digested with HF‐HBr and Br2, and subsequently decomposed at 518 K in a Teflon bomb. In this procedure, all sulfides and chromite, major hosts of these elements, were completely decomposed, thus allowing for isotope equilibration between the sample and spike. Magnesium and Al fluorides formed after the digestion of the sample were removed by centrifugation, and the supernatant was directly aspirated into a HR‐ICP‐MS at a mass resolution of 7500, where interfering oxide ions, ArO+, CaO+, TiO+, CrO+ and VO+, were separated from Cr+, Ni+, Cu+ and Zn+. No matrix effects were observed down to a dilution factor of 50. Detection limits for these elements in silicate samples were < 0.04 μg g?1. The effectiveness of the technique was demonstrated by the analysis of 13 to 40 mg test portions of USGS and GSJ silicate reference materials with a major element composition ranging from andesite to peridotite, in addition to 8‐23 mg of the Smithsonian reference Allende. Both the reproducibility and the deviation from the reference value for most reference materials of various rock types were < 9%, and thus confirm that the method gives accurate analytical results for small sample sizes over a wide range of Cr, Ni, Cu and Zn contents. This method is, therefore, suitable for analysing small and/or precious bulk samples, such as meteorites, mantle peridotites and mineral separates, and for the characterisation of silicate and sulfide minerals for use as calibration samples in secondary ion mass spectrometry or laser ablation ICP‐MS. 相似文献