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41.
42.
Ashok Kumar Deepak Srivastava Sanjay Kumar Srivastava 《Journal of the Indian Society of Remote Sensing》1994,22(1):57-64
Remotely-sensed satellite data of Landsat 5 (TM) and IRS-1A (LISS II) covering parts of central portion of Chotanagapur plateau have been analysed visually to delineate some prominent lineaments in Ranchi district and its adjoining area. One of the most prominent lineament “Ranchi mega lineament? has been analysed in this paper. This lineament is a potential site for base metal mineralisation at some places, and it acts as good groundwater conduit in the region. No earlier attempt to map this entire structural unit as a separate entity is known. Geophysical bouguer gravity anomaly map, lithological and structural maps have some remarkable correlation with this lineament. In the present paper authors have tried to analyse the lineament with respect to its tectonic, mineralisation and groundwater prospects. Resistivity survey carried in close proximity of this lineament at selected sites, indicate that rocks are well fractured at depth. Available lithological and structural map support this lineament as a shear near Purulia (W.B.) and also having base-metal mineralisation potential in this area. Authors opine that existing gravity anomaly map may be further augmented in the light of present study. 相似文献
43.
Fluorescence efficiencies of electrons in a large number of bands of the N2 First Positive and O2+ First Negative groups lying in the 4900–10,500 Å wavelength range have been investigated theoretically. The variation of transition moment with internuclear distance is taken into consideration. For the First Positive group of N2 the calculations are carried out at very low pressure as well as at 600 Torr. In general the present values are higher than the experimental values but in most of the cases fair agreement has been obtained. For the O2+ First Negative group no direct experimental data is available. However, the present ratio of the total efficiency in the O2+ First Negative group to the N2+ First Negative group is found to be in good agreement with the experimental intensity ratio. 相似文献
44.
Forecasting monthly precipitation using sequential modelling 总被引:1,自引:1,他引:0
In the hydrological cycle, rainfall is a major component and plays a vital role in planning and managing water resources. In this study, new generation deep learning models, recurrent neural network (RNN) and long short-term memory (LSTM), were applied for forecasting monthly rainfall, using long sequential raw data for time series analysis. “All-India” monthly average precipitation data for the period 1871–2016 were taken to build the models and they were tested on different homogeneous regions of India to check their robustness. From the results, it is evident that both the trained models (RNN and LSTM) performed well for different homogeneous regions of India based on the raw data. The study shows that a deep learning network can be applied successfully for time series analysis in the field of hydrology and allied fields to mitigate the risks of climatic extremes. 相似文献
45.
Along a north-south transect (9.69°N to 55.01°S) in the southwestern Indian Ocean during the Indian Pilot Expedition to Southern Ocean (PESO), the oxygen isotopic analysis of planktic foraminifera (Globigerina bulloides) from 23 surface sediment samples was carried out to assess the relationship between isotopic composition of G. bulloides and the prevailing physical (seawater temperature and salinity) conditions of the ambient seawater. An increasing trend in the δ18O value is noticed towards higher latitude. Apparently such an increase in δ18O values is inversely related to the temperature changes along the transect. However, slight mismatch is observed at a few stations due to calcification out of optimum conditions or due to the salinity changes. The preliminary results of the present study, if extended to the subsurface sediments coupled with other parameters, may contribute to the reconstruction of the paleohydrography of the region, especially the position of various seawater fronts during the geologic past albeit with areal limitation. 相似文献
46.
We have analysed a large, homogeneous sample of Lyman alpha lines, observed at intermediate resolution, using the maximum
likelihood method. The analysis shows that the evolutionary index γ, is a function of rest equivalent width with stronger
lines evolving faster. The mean equivalent width increases with redshift. This behaviour is similar to that exhibited by the
heavy element absorption lines in the quasar spectra. 相似文献
47.
Pushpa Khare 《Journal of Astrophysics and Astronomy》1997,18(4):257-261
I summarize the properties of the QSO absorption lines which provide evidence for the standard model of the Universe. 相似文献
48.
Fluorescence efficiencies of electrons in a large number of bands of N2 second positive and N2+ first negative groups lying in the 3000–5200 Å region are calculated. At very low pressure where quenching is negligible the present values are within 15 per cent of the experimental data of Hartmann (1968). The efficiencies are found to be independent of the impact energies greater than 200 eV which is in accordance with other theoretical and experimental results. The ratio of the total efficiencies in N2 second positive and N2+ first negative groups is 1·31 and is about 20 per cent lower than the experimental values. The efficiencies at a higher pressure equal to 600 torr are compared with the experimental data of Davidson and O'Neil (1964a). 相似文献
49.
M. Shakir Khan M. Zubair Deepak Verma A. H. Naqvi Ameer Azam M. K. Bhardwaj 《Environmental Earth Sciences》2011,63(2):279-282
Radon and its progeny have been recognized as one of the major contributors to the natural radiation and health hazards in
the human dwellings. Even lung cancer is expected if it is present in enhanced levels beyond maximum permissible limit. This
paper reports the measurements of indoor radon and its progeny in the urban dwellings of the Etah district of Uttar Pradesh
province in Northern India using the cellulose nitrate (LR-115 type-II) plastic track detectors. It is found that the values
of radon concentration vary from 3.52 to 248.64 Bq m−3 with a standard deviation of 69.19. The values of radon progeny concentration vary from 0.38 to 26.88 mWL with a standard
deviation of 7.48. The effective dose has been calculated and found to vary from 0.05 to 3.76 mSv year−1 with a standard deviation of 1.05. The lifetime fatality risk is found to vary from 0.04 × 10−4 to 2.90 × 10−4. The results have been compared with the results reported in the rural areas of the same district. 相似文献
50.
Abhay M. Varade Y. D. Khare Poonam Yadav A. P. Doad Sandipan Das Madhura Kanetkar R. B. Golekar 《Journal of the Indian Society of Remote Sensing》2018,46(4):539-549
Hard rock aquifer system, as it lacks in primary porosity, is complex because of heterogeneity, and hence its performance solely depends on secondary factors such as weathering, fractures, joints and lineaments, etc. As a result, there is no uniformity in behavior of such aquifer system which varies with the intensity of factors causing secondary porosity. In view of this aquifer system of hard rock, particularly multilayered aquifer system such as basalt, the targeting of deeper aquifer system becomes uncertain. Under this situation, mapping of lineament assumes great importance particularly for targeting the deeper aquifer. In view of this, a small watershed WGKKC-2 falling in Nagpur District of Central India has been studied in detail to understand the significance of lineaments on governing deeper aquifer system. The study has been carried out by deploying remote sensing technique for delineation of hydro geomorphology and lineaments vis-à-vis performance of bore wells. The results are encouraging which mainly emphasize the role of lineament mapping in hard rock aquifer system for identification of groundwater potential zones. 相似文献