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641.
Lucie Novakova Milan Broz Jiri Zaruba Karel Sosna Jan Najser Lenka Rukavickova Jan Franek Vladimir Rudajev 《应用地球物理》2016,13(2):315-325
Underground storage systems are currently being used worldwide for the geological storage of natural gas (CH4), the geological disposal of CO2, in geothermal energy, or radioactive waste disposal. We introduce a complex approach to the risks posed by induced bedrock instabilities in deep geological underground storage sites. Bedrock instability owing to underground openings has been studied and discussed for many years. The Bohemian Massif in the Czech Republic (Central Europe) is geologically and tectonically complex. However, this setting is ideal for learning about the instability state of rock masses. Longterm geological and mining studies, natural and induced seismicity, radon emanations, and granite properties as potential storage sites for disposal of radioactive waste in the Czech Republic have provided useful information. In addition, the Czech Republic, with an average concentration radon of 140 Bq m?3, has the highest average radon concentrations in the world. Bedrock instabilities might emerge from microscale features, such as grain size and mineral orientation, and microfracturing. Any underground storage facility construction has to consider the stored substance and the geological settings. In the Czech Republic, granites and granitoids are the best underground storage sites. Microcrack networks and migration properties are rock specific and vary considerably. Moreover, the matrix porosity also affects the mechanical properties of the rocks. Any underground storage site has to be selected carefully. The authors suggest to study the complex set of parameters from micro to macroscale for a particular place and type of rock to ensure that the storage remains safe and stable during construction, operation, and after closure. 相似文献
642.
The western part of the Bohemian Massif (West-Bohemia/Vogtland region at the Czech-German border) is characterized by relatively
frequent intraplate earthquake swarms and by other manifestations of present-day geodynamic activity. During the strong earthquake
swarm at the turn of the years 1985 and 1986, significant changes in mineral spring parameters were observed at the spa of
Františkovy Lázně. In this study, we present all available data on the mineral springs parameters, and we discuss them in
terms of relations to seismic activity. Some changes in discharge were very distinct, amounting up to 40%, and had a co-seismic
character. The changes in temperature were less noticeable, but preceded the beginning of the swarm by several months. Some
hydrological changes persisted for nearly two years after the earthquake swarm. The character of the observed changes seems
to support the hypothesis on an injection of mantle fluids, in particular of CO2, as the main triggering mechanism of the earthquake swarm and the main cause of discharge anomalies. 相似文献
643.
Galliski Miguel Ángel Márquez-Zavalía María Florencia Škoda Radek Novák Milan Čopjaková Renata Pagano Diego Sebastián 《Mineralogy and Petrology》2019,113(5):687-701
Mineralogy and Petrology - An assemblage of tantalite-(Mn), tantalian rutile, tapiolite-(Fe), titanowodginite, ferrotitanowodginite, and hydroxycalciomicrolite occurs in the Nancy granitic... 相似文献
644.
利用EISCAT VHF和EISCAT Svalbard(ESR)雷达观测数据,对2003年2月12日IMF Bz分量4次快速方向转换期间,极区电离层,尤其是极尖/极隙区的响应特征进行了分析研究.随着IMF Bz方向的多次快速变化,地面雷达观测到极尖/极隙区所在位置随着开放-闭合磁力线边界在纬度方向上来回移动.在此期间,极区电离层等离子体水平对流多次反向,表现出与IMF Bz分量强的负相关性.进一步分析表明:极区磁层-电离层系统在日侧对IMF极性变化的平均响应时间约为3 min. 相似文献
645.
For more than a decade, habitat mapping using biotopes (in‐channel hydraulically‐defined habitats) has underpinned aquatic conservation in the UK through (a) providing baseline information on system complexity and (b) allowing environmental and ecological change to be monitored and evaluated. The traditional method used is the subjective river habitat or corridor survey. This has recently been revised to include the floodplain via GeoRHS, but issues still exist concerning development of a national database due to the labour intensive nature of the data collection, subjectivity issues between samplers, temporal changes, the fuzzy nature of perceived habitats and habitat boundaries. This paper takes an innovative approach to biotope definition using high resolution spatial data to define water surface roughness for two representative reaches of the River South Tyne, Cumbria, and the River Rede, Northumberland, UK. Data was collected using a terrestrial laser scanner (TLS) and hydraulic variability simply expressed through assigning a local standard deviation value to a set of adjacent water surface values. Statistical linkage of these data with biotope locations defined visually in the field allowed complete mapping of the surveyed reach defining habitat and biotope areas to the fine scale resolution of the TLS data. Despite issues of data loss due to absorption and transmission through the water, the reflected signal generated an extremely detailed and objective map of the water surface roughness, which may be compared with known biotope locations as defined by visual identification in the field. The TLS accuracy achieved in the present study is comparable with those obtained using hyperspectral imagery: with 84% of the pool/glide/marginal deadwater amalgamated biotope, 88% of riffles, 57% of runs and 50% of the amalgamated cascade/rapid biotope successfully plotted. It is clear from this exercise that biotope distribution is more complex than previously mapped using subjective techniques, and based upon the water surface roughness delimiters presented in this study, the amalgamation of pools with glides and marginal deadwaters, riffles with unbroken standing waves, and cascades with rapids, is proposed. Copyright © 2010 John Wiley & Sons, Ltd 相似文献
646.
Zbyněk Engel Grzegorz Skrzypek Debajyoti Paul Wojciech Drzewicki Daniel Nývlt 《Journal of Paleolimnology》2010,43(4):609-624
This study presents detailed lithostratigraphy and stable carbon and nitrogen isotopic variations in a 520-cm-long sediment
core from a cirque basin in the Labsky důl Valley, Krkonoše Mountains, Czech Republic. Detailed study of the core reveals
five major periods of sedimentation during the last 7600 years: silt and sand deposition during ~7.6–5.1 ka cal BP, Sphagnum peat accumulation during ~5.1–4.0 ka cal BP, sandy silt and sand during ~4.0–2.8 ka cal BP, raised peat bog during ~2.8–2.0 ka cal
BP (Sphagnum peat), and sedimentation of sandy silt since ~2.0 ka cal BP. The δ13C values of the organic matter in the core vary in the range typical for C3 plants, from −24.35 to −27.68‰, whereas the δ15N values vary from −2.65 to +4.35‰. Core sections having ash contents ≥70% have δ15N > 1‰ and δ13C < −26‰, whereas those having ≤70% ash content have δ15N < 1‰ and δ13C > −26‰. Strong linear correlations are observed between δ13C and δ15N values as well as between C:N ratios and δ15N values in the horizons with ash content >10%, primarily for sand and silt horizons. On the other hand, poor correlations
between δ13C and C:N ratio, as well as δ15N and C:N ratio, were observed in Sphagnum peat layers (45–125 and 185–265 cm). We conclude that the primary stable isotope variations are not preserved in the layers
where significant correlation between δ15N and C:N ratio is observed. The relatively small δ13C variation in the uppermost Sphagnum peat layer suggests stable temperature during ~2.8–2.0 ka cal BP. 相似文献
647.
Minarovjech Milan Rušin Vojtech Rybanský Milan Sakurai Takashi Ichimoto Kiyoshi 《Solar physics》2003,213(2):269-290
We studied intensity oscillations of the coronal green line ([Fexiv] 530.3 nm) observed with two coronagraphs at Lomnický tít and Norikura nearly simultaneously. In the spectroscopic data obtained at Norikura, we have detected and confirmed the earlier detection of 5-minute oscillations in photoelectric photometer observations made at Lomnický tít. Quasi-periodic structures in the green-line intensity with a tangential speed up to 400 km s–1 have been detected for the first time. We briefly discuss the implications of these oscillations on the coronal heating mechanisms. 相似文献
648.
S. Ferraz-Mello J. C. Klafke T. A. Michtchenko D. Nesvorný 《Celestial Mechanics and Dynamical Astronomy》1996,64(1-2):93-105
The utilization of chaotic dynamics approaches allowed the identification of many modes of motion in resonant asteroidal dynamics. As these dynamical systems are not integrable, the motion modes are not separated and one orbit may transit from one mode to another. In some cases, as in the \31 resonance, these transitions may lead, in a relatively short time scale, to eccentricities so high that the asteroid may approach the Sun and be destroyed. In the \21 and \32 resonances these transitions are much slower and only indirect estimations of the time which is needed for a generic asteroid to leave the resonance are possible. It may reach hundreds of million years in the more robust regions of the \21 resonance and a time of the order of billions of years in those of the \32 resonance. These values are consistent with the observed depletion of the \21 resonance (only a few asteroids known while almost 60 asteroids are known in the \32 resonance). 相似文献
649.
650.