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91.
Assessment of heavy metal contamination in soils around Manali industrial area, Chennai, Southern India 总被引:4,自引:0,他引:4
The concentrations of heavy metals (As, Ba, Co, Cr, Cu, Ni, Mo, Pb, Sr, V and Zn) were studied in soils to understand metal
contamination due to industrialization and urbanization around Manali industrial area in Chennai, Southern India. This area
is affected by the industrial activity and saturated by industries like petrochemicals, refineries, and fertilizers generating
hazardous wastes. The contamination of the soils was assessed on the basis of geoaccumulation index, enrichment factor (EF),
contamination factor and degree of contamination. Soil samples were collected from the industrial area of Manali from the
top 10-cm-layer of the soil. Soil samples were analyzed for heavy metals by using Philips MagiX PRO-2440 Wavelength dispersive
X-ray fluorescence spectrometry. The data revealed elevated concentrations of Chromium (149.8–418.0 mg/kg), Copper (22.4–372.0 mg/kg),
Nickel (11.8–78.8 mg/kg), Zinc (63.5–213.6 mg/kg) and Molybdenum (2.3–15.3 mg/kg). The concentrations of other elements were
similar to the levels in the earth’s crust or pointed to metal depletion in the soil (EF < 1). The high-EFs for some heavy
metals obtained in the soil samples show that there is a considerable heavy metal pollution, which could be correlated with
the industries in the area. Contamination sites pose significant environmental hazards for terrestrial and aquatic ecosystems.
They are important sources of pollution and may result in ecotoxicological effects on terrestrial, groundwater and aquatic
ecosystems. In this perspective there is need for a safe dumping of waste disposal in order to minimize environmental pollution. 相似文献
92.
Janet M. Hergt L. Paul Bédard Stefanie M. Brueckner Klaus Peter Jochum Kathryn L. Linge Paul J. Sylvester Michael Wiedenbeck Jon D. Woodhead 《Geostandards and Geoanalytical Research》2008,32(4):397-398
In 2005 the Geostandards and Geoanalytical Research editorial team, in the true spirit of scientific endeavour, embarked on an experiment of our own. We decided to trial a new kind of review, somewhat different from those more typically observed in journals, and one that would provide readers with a summary of analytical developments across a broad range of topics appropriate to the Earth sciences. The first contribution of this kind appeared in 2005, and reported on developments in 2003 (Hergt et al. 2005). The second, this time a biennial review, was published in 2006 and reported on highlights of the 2004 and 2005 literature (Hergt et al. 2006). Based on reprint requests, positive remarks at conferences and strong citations we consider the experiment a resounding success and proudly present here the third in this series. This comprises six individual review sections that cover the main analytical technologies and topical application fields in geoanalysis and geochemistry, including geological and environmental reference materials, ICP‐thermal and secondary ionisation‐mass spectrometry, as well as neutron activation analysis, X‐ray fluorescence and atomic absorption spectrometry. 相似文献
93.
Stefan Lauterbach Achim Brauer Nils Andersen Dan L. Danielopol Peter Dulski Matthias Hüls Krystyna Milecka Tadeusz Namiotko Milena Obremska Ulrich Von Grafenstein Declakes Participants 《第四纪科学杂志》2011,26(3):253-267
Investigation of the sedimentary record of pre‐Alpine Lake Mondsee (Upper Austria) focused on the environmental reaction to rapid Lateglacial climatic changes. Results of this study reveal complex proxy responses that are variable in time and influenced by the long‐term evolution of the lake and its catchment. A new field sampling approach facilitated continuous and precisely controlled parallel sampling at decadal to sub‐annual resolution for µ‐XRF element scanning, carbon geochemistry, stable isotope measurements on ostracods, pollen analyses and large‐scale thin sections for microfacies analysis. The Holocene chronology is established through microscopic varve counting and supported by accelerator mass spectrometry 14C dating of terrestrial plant macrofossils, whereas the Lateglacial age model is based on δ18O wiggle matching with the Greenland NGRIP record, using the GICC05 chronology. Microfacies analysis enables the detection of subtle sedimentological changes, proving that depositional processes even in rather large lake systems are highly sensitive to climate forcing. Comparing periods of major warming at the onset of the Lateglacial and Holocene and of major cooling at the onset of the Younger Dryas reveals differences in proxy responses, reflecting threshold effects and ecosystem inertia. Temperature increase, vegetation recovery, decrease of detrital flux and intensification of biochemical calcite precipitation at the onset of the Holocene took place with only decadal leads and lags over a ca. 100 a period, whereas the spread of woodlands and the reduction of detrital flux lagged the warming at the onset of the Lateglacial Interstadial by ca. 500–750 a. Cooling at the onset of the Younger Dryas is reflected by the simultaneous reaction of δ18O and vegetation, but sedimentological changes (reduction of endogenic calcite content, increase in detrital flux) were delayed by about 150–300 a. Three short‐term Lateglacial cold intervals, corresponding to Greenland isotope substages GI‐1d, GI‐1c2 and GI‐1b, also show complex proxy responses that vary in time. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
94.
95.
利用同步辐射X射线荧光技术,对人工合成金刚石以及产自山东、辽宁、湖南的天然金刚石进行了微量元素的测试分析。结果表明,在合成金刚石中,检测到了第四周期的元素(除As、Ge、Kr和Br外)和Pb;其中Fe、Co、Ni相对含量高,可能是合成时触媒的混入引起的。天然金刚石中检测到的微量元素有Ca、Ti、Cr、Mn、Fe、Co、Ni、Cu、Zn、W、Au和Pb,但相对含量比合成金刚石中相应的微量元素相对含量低。不同产地的天然金刚石中的微量元素种类及含量存在差异,反映了金刚石地幔生长环境的不同及岩浆对金刚石生长过程的影响。 相似文献
96.
97.
A组煤(1煤)是矿井延伸开采的主要煤层,受底板承压岩溶水威胁。随着开采深度的增加,A组煤层底板灰岩突水几率也随之逐渐增大。采集谢桥矿A组煤层底板石炭系太原组石灰岩样品及对应层位的太灰水样品,并对不同层石灰岩样品进行显微镜下、X射线衍射(XRD)以及X射线荧光光谱(XRF)分析,对水样进行常规离子组分的测试分析,探讨了A组煤石灰岩矿物组成、化学组分及离子含量之间的关系。研究结果表明:太原组C2Ⅰ层和C2Ⅲ层石灰岩孔隙发育,溶蚀能力强,为含水层;C2Ⅱ层石灰岩裂隙不发育,岩溶不发育,为相对隔水层;太灰水中Ca2+、Mg2+、Na+、K+含量主要与石灰岩组成、pH值以及阳离子交换作用有关;Cl-含量与沉积水体盐度相一致。将岩石的矿物学特征与地下水化学组成同时进行研究对A组煤开采可行性分析具有重要现实意义。 相似文献
98.
99.
By now there is no doubt that the gamma-ray bursts (GRB) have a cosmological origin. This allows to regard GRB as the most
powerful known energy sources, ε∼ 1054 erg (with a total number of gamma quanta N_γ∼ 1060). A plausible mechanism of coherent synchrotron radiation (CSR) of relativistic electrons driven by a local magnetic field
is studied in this paper. We consider relativistic electrons arising in the Compton scattering of a GRB in directions close
to that of the ray from the source to a ground-based observer. The synchrotron pulses from Compton electrons located at different
points on the line between the GRB source and the observer arrive at the observation point simultaneously. This simultaneity
ensures the coherence of the detected radiation. Both molecular clouds in the host galaxy of the GRB and our own Galaxy, as
well as the Earth atmosphere are assumed to be scatterers of the GRB radiation. Signals of each scatterer reach the Earth
surface, and can be detected at radio wavelengths. We estimate the characteristics of this radiation. The comparison of GRB
data with the corresponding information on CSR pulses offers a way to determine some global characteristics of the medium
between the Earth and the GRB source. 相似文献
100.
An explicit formula is developed to explore the mechanism of the synchrotron radiation by using a bi-modal loss-cone distribution function. The variation of the distribution function along the field line is modeled in detail and the evaluation of the total power in the synchrotron radiation is presented. The variance of synchrotron radiation with latitude depends on the electron anisotropy; for low anisotropy, synchrotron radiation increases with latitude and reaches a maximum at the particle mirror points; for high anisotropy, it decreases with latitude and maximizes at the equator. A bi-modal population is therefore suggested to explain the radiation intensity which peaks both at the equator and at high latitude. 相似文献