全文获取类型
收费全文 | 133篇 |
免费 | 2篇 |
国内免费 | 3篇 |
专业分类
测绘学 | 11篇 |
大气科学 | 8篇 |
地球物理 | 16篇 |
地质学 | 78篇 |
天文学 | 22篇 |
综合类 | 2篇 |
自然地理 | 1篇 |
出版年
2022年 | 6篇 |
2021年 | 1篇 |
2020年 | 6篇 |
2019年 | 2篇 |
2018年 | 13篇 |
2017年 | 11篇 |
2016年 | 11篇 |
2015年 | 8篇 |
2014年 | 9篇 |
2013年 | 5篇 |
2012年 | 11篇 |
2011年 | 4篇 |
2010年 | 7篇 |
2009年 | 7篇 |
2008年 | 11篇 |
2007年 | 3篇 |
2006年 | 6篇 |
2005年 | 6篇 |
2004年 | 4篇 |
2003年 | 2篇 |
2002年 | 1篇 |
2001年 | 1篇 |
1998年 | 1篇 |
1996年 | 2篇 |
排序方式: 共有138条查询结果,搜索用时 31 毫秒
41.
The rare earth element patterns of the gneisses of Bastar and Bundelkhand are marked by LREE enrichment and HREE depletion
with or without Eu anomaly. The spidergram patterns for the gneisses are characterized by marked enrichment in LILE with negative
anomalies for Ba, P and Ti. The geochemical characteristics exhibited by the gneisses are generally interpreted as melts generated
by partial melting of a subducting slab. The style of subduction was flat subduction, which was most common in the Archean.
The rare earth patterns and the multi-element diagrams with marked enrichment in LILE and negative anomalies for Ba, P and
Ti of the granitoids of both the cratons indicate interaction between slab derived melts and the mantle wedge. The subduction
angle was high in the Proterozoic. Considering the age of emplacement of the gneisses and granitoids that differs by ∼ 1 Ga,
it can be assumed that these are linked to two independent subduction events: one during Archaean (flat subduction) that generated
the precursor melts for the gneisses and the other during the Proterozoic (high angle subduction) that produced the melts
for the granitoids. The high values of Mg #, Ni, Cr, Sr and low values of SiO2 in the granitoids of Bastar and Bundelkhand cratons compared to the gneisses of both the cratons indicate melt-mantle interaction
in the generation of the granitoids. The low values of Mg#, Ni, Cr, Sr and high values of SiO2 in the gneisses in turn overrules such melt-mantle interaction. 相似文献
42.
S. N. Tandon J. B. Hutchings S. K. Ghosh A. Subramaniam G. Koshy V. Girish P. U. Kamath S. Kathiravan A. Kumar J. P. Lancelot P. K. Mahesh R. Mohan J. Murthy S. Nagabhushana A. K. Pati J. Postma N. Kameswara Rao K. Sankarasubramanian P. Sreekumar S. Sriram C. S. Stalin F. Sutaria Y. H. Sreedhar I. V. Barve C. Mondal S. Sahu 《Journal of Astrophysics and Astronomy》2017,38(2):28
The performance of the ultraviolet telescope (UVIT) on-board AstroSat is reported. The performance in orbit is also compared with estimates made from the calibrations done on the ground. The sensitivity is found to be within \(\sim \)15% of the estimates, and the spatial resolution in the NUV is found to exceed significantly the design value of \(1.8^{\prime \prime }\) and it is marginally better in the FUV. Images obtained from UVIT are presented to illustrate the details revealed by the high spatial resolution. The potential of multi-band observations in the ultraviolet with high spatial resolution is illustrated by some results. 相似文献
43.
Sisir K. Mondal 《Journal of the Geological Society of India》2011,78(4):390-391
News and Notes
National Seminar on Orissa’s Mineral, Environment and Geosciences Assessment — 2011 (OMEGA-2011) and Golden Jubilee of Geological Survey of India, Orissa — M. Mohanty and K. C. Sahoo (Email: manoranjanmoha@gmail.com) 相似文献44.
45.
46.
Saurodeep Chatterjee Supriya Mondal Debesh Gain Tapan Kr Baidya Dipanjan Mazumdar 《Journal of Earth System Science》2018,127(6):89
The present work deals with the generations of Fe–Ti oxides and the variation in magnetic fabrics of the Dalma lavas and associated meta-sediments of the Singhbhum Mobile Belt (SMB) in relation to tectonics. Generations of the Fe–Ti oxides are different in meta-sediments and volcanics, the former preserving upliftment related oxidised grains, whereas the latter contains fresh grains prompting towards their upliftment due to plume upwelling before the volcanic eruption. In the meta-sediments, the magnetic fabric has close accordance with \(\hbox {D}_{2}/\hbox {F}_{2}\) event revealing synchronous development with \(\hbox {D}_{2}\). The Dalma thrust developed a sudden break in the homogeneity of the magnetic fabrics of the rocks where the magnetic foliations are all parallel to the Dalma thrust. This also causes \(P_{j}\) to be highest in this sector. The magnetic fabrics of volcanic rocks are different from the meta-sediments and record no signature of deformation. The pattern of distribution of susceptibility axes are in accordance with the subaerial lava flows. However, their \(\hbox {K}_{1}\) and \(\hbox {K}_{2}\) dispersed throughout the periphery with \(\hbox {K}_{3}\) clustering at the centre. This infers towards the fact that although the volcanism took place in a subaerial environment, calm aqueous environment was locally present where the oblate grains settled on the eruption surface with their \(\hbox {K}_{3}\) vertical. 相似文献
47.
North-eastern Himalaya is said to be one of the world most complex geological set-up with different kinds of seismotectonic systems. Region has experienced two of the world’s strongest earthquakes, such as Shillong earthquake of 1897 known as Assam earthquake and subsequent 1950 earthquake in Arunachal Pradesh, both of with magnitude of 8.7, and also several other strong earthquakes. Various techniques have been applied to understand the past strong earthquake mechanism as well as hazard estimation carried out for future earthquake. Fractal correlation dimension (D c) is being used in this study with the seismicity for the period 1961 to recent for understanding the pattern of seismic hazard. The entire area has been divided into four major tectonic blocks, and each block event was divided into consecutive fifty events window for seeing spatiotemporal patterns. After comparing the patterns, we have identified that Block of Eastern Himalaya near Main Central Thrust, Main Boundary Thrust, north of Kopili lineament and Block of Shillong plateau near Dauki fault are having relatively intense clustering of events in recent times, which may be identified as the zones of most potential to have a strong event. 相似文献
48.
B. Das N. K. Mondal R. Bhaumik P. Roy 《International Journal of Environmental Science and Technology》2014,11(4):1101-1114
In the present study, adsorption of lead (II) ions from aqueous solution by alluvial soil of Bhagirathi River was investigated under batch mode. The influence of solution pH, sorbent dose, initial lead (II) concentration, contact time, stirring rate and temperature on the removal process were investigated. The lead adsorption was favored with maximum adsorption at pH 6.0. Sorption equilibrium time was observed in 60 min. The equilibrium adsorption data were analyzed by the Freundlich, Langmuir, Dubinin–Radushkevich and Temkin adsorption isotherm models. The kinetics of lead (II) ion was discussed by pseudo first-order, pseudo second-order, intra-particle diffusion, and surface mass transfer models. It was shown that the adsorption of lead ions could be described by the pseudo second-order kinetic model. The activation energy of the adsorption process (E a) was found to be ?38.33 kJ mol?1 using the Arrhenius equation, indicating exothermic nature of lead adsorption onto alluvial soil. Thermodynamic parameters, such as Gibbs free energy (?G 0), the enthalpy (?H 0), and the entropy change of sorption (?S 0) have also been evaluated and it has been found that the adsorption process was spontaneous, feasible, and exothermic in nature. The results indicated that alluvial soil of Bhagirathi River can be used as an effective and low cost adsorbent to remove lead ions from aqueous solutions. 相似文献
49.
50.
Natural Hazards - Investigations of micro- and low-magnitude earthquakes in the Kangra-Chamba region of the NW Himalaya were performed to evaluate the relationship between earthquake source,... 相似文献