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51.
S. Lal L. K. Sahu S. Gupta S. Srivastava K. S. Modh S. Venkataramani T. A. Rajesh 《Journal of Atmospheric Chemistry》2008,60(3):189-204
Measurements of surface O3, CO, NOx and light NMHCs were made during December 2004 at Hissar, a semi-urban site in the state of Haryana in north-west region
of the Indo-Gangetic Plain (IGP). The night-time O3 values were higher when levels of CO, NO and NO2 were lower but almost zero values were observed during the episodes of elevated mixing ratios of CO (above 2000 ppbv) and
NOx (above 50 ppbv). Slopes derived from linear fits of O3 versus CO and O3 versus NOx scatter plots were also negative. However, elevated levels of O3 were observed when CO and NOx were in the range of 200–300 ppbv and 20–30 ppbv, respectively. Slope of CO-NOx of about 33 ppbv/ppbv is much larger than that observed in the US and Europe indicating significant impact of incomplete
combustion processes emitting higher CO and lesser NOx. Correlations and ratios of these trace gases including NMHCs show dominance of recently emitted pollutants mostly from biomass
burning at this site. 相似文献
52.
Mathematical Geosciences - The present study presents the propagation of horizontally polarized shear waves (SH-waves) in highly anisotropic layered media under the effect of horizontal and... 相似文献
53.
Chemical components such as SiO
2,TiO
2,MnO, P
2
O
5,and especially Fe
2
O
3
of the iron ores of Bicholim Mine, Northern Goa, have been determined for lateral and vertical sections of the mine at equal intervals of 3 and 1 m, respectively, so as to form the spatial (time) series. Univariate stationary models of the type Autoregressive moving average—ARMA (p, q)—were established for each series on the basis of statistical analyses of their auto (acf) and partial auto (pacf) correlation functions. These models were used for forecasting assay values at different lead distances from any pivot. Principles of parsimony simplified all of the candidate ARMA (p, q) models to pure AR (p) models, and the univariate forecasts were significantly improved by multivariate stochastic forecasts. 相似文献
54.
Basanta K. Sahu 《Mineralium Deposita》1982,17(1):99-105
Mineral deposits are characterized by certain continuity of assay values, thickness and top and bottom surfaces of ore zones etc., which are amenable to stochastic modelling with respect to spatial coordinates. The French School (Matheron, 1963) introduced rather difficult terminology of semi-variogram, kriging etc. for quantitative assessment of reserves and average grade of mining property under the assumption of second-order stationarity of first differenced (d=1) data. A more general, powerful and well-known time-domain (spatial) stochastic models (ARIMA (p, d, q); based on Box and Jenkins, 1970, 1976; Anderson, 1976) are introduced herein which include Matheron Model (d=1) as a special case. 相似文献
55.
S. S. Rathore A. R. Vijan M. P. Singh B. N. Prabhu Anand Sahu 《Journal of Earth System Science》2004,113(1):27-36
Precambrian granitic basement rocks obtained from well BH-36 of Bombay High Field, western offshore of India has been studied
both by Rb-Sr and K-Ar dating methods. Seven basement samples chosen from two cores have yielded whole rock Rb-Sr isochron
age of 1446 ± 67 Ma with an initial87Sr/86Sr ratio of 0.7062 ± 0.0012. This age has been interpreted as the formation/emplacement time of the granite. Two biotite fractions
of different grain size separated from a sample CC6B2T have yielded Rb-Sr mineral isochron age of 1385 ± 21 Ma. However, these
fractions when studied by K-Ar dating method have yielded slightly higher but mutually consistent ages of 1458 ± 43 Ma and
1465 ± 43 Ma, respectively.
Further, two biotites separated from additional samples CC5B9T and CC6B3B have yielded K-Ar ages of 1452 ± 42 Ma and 1425
± 40 Ma with an overall mean age of 1438 ± 19 Ma. This mean K-Ar age is indistinguishable from whole rock Rb-Sr isochron as
well as mineral isochron age within experimental error. The similarity in the whole rock and biotite ages obtained by different
isotopic methods suggests that no thermal disturbance has occurred in these rocks after their emplacement/formation around
1450 Ma ago. The present study provides the evidence for the existence of an important Middle Proterozoic magmatic event around
1400-1450 Ma on the western offshore of India which, hitherto, was thought to be mainly confined to the eastern Ghats, Satpura
and Delhi fold belt of India. This finding may have an important bearing on the reconstruction of Proterozoic crustal evolution
of western Indian shield. 相似文献
56.
57.
The ability of seven hyperaccumulator macrophytes which grow naturally in the heavy metal contaminated channels of three different industries (Hindustan Aeronautical Ltd., Eveready Ltd., and Scooter India Ltd.) to accumulate heavy metals was recorded. All these industries use electroplating processes in their manufacturing and are located in the inner area of Lucknow City, U.P., India. Of the three industries monitored, effluent released from Eveready Ltd. contained the highest concentration of heavy metals. In general, accumulations of heavy metals depend upon the plant species and the metal concentration in the media. All plant samples showed heterogeneous metal accumulations, except for Fe or Cd. It was observed that some plant species accumulated high level of metals, e. g., Eichhornnia crassipes for Fe (4052.44 μg/g), Mn (788.42 μg/g), and Cu (315.50 μg/g), and Spirodela polyrhiza for Cd (12.75 μg/g), Pb (20.25 μg/g), and Cr (128.27 μg/g), even when the metal concentrations were not high in the effluent. In summary, these two plants were found to be the best accumulators at each contaminated site. The results will be helpful in the selection of plant species which can be used as bioaccumulators or bioindicators. 相似文献
58.
Amit Shiuly R. B. Sahu Saroj Mandal Narayan Roy 《Journal of the Geological Society of India》2018,91(4):400-410
Kolkata, capital of West Bengal, India, presently congested with moderate to high rise buildings, has undergone low to moderate damages due to past earthquakes. The city is situated on the world’s largest delta island with soft thick alluvial soil layer. In this study, an attempt has been made to study ground response due to a number of past earthquakes, 1897 Shillong earthquake, 1964 Calcutta earthquake and 2011 Sikkim earthquake, for the purpose of preliminary microzonation of the Kolkata city. For this, synthetic ground motions have been generated at bedrock level by stochastic method. By using 1D wave propagation technique, the synthetic ground motion has been computed at surface level for 144 borehole locations in the city. Contours of PGA, PGV and PGD parameters in the city have been drawn for these three earthquakes. Response spectra for these three earthquakes have also been computed and an optimum response spectrum has been determined. A good correlation has been obtained with predicted ground motion at surface level of the city with the reported intensity and damages occurred in buildings of Kolkata during past earthquakes. The scenario of simulated ground motion for the past three earthquakes depicts that Kolkata city is very much prone to damages even due to moderate far and near source earthquakes. 相似文献
59.
This paper studies the reliability of the calculated shear-wave velocity (\(V_{\mathrm{S}}\)) from different available \(V_{\mathrm{S}}\) and SPT-N correlations in terms of seismic site response analysis. In the present study, various \(V_{\mathrm{S}}\)–N correlations developed for different regions around the globe have been used to calculate the bound of \(V_{\mathrm{S}}\) variations with depth at three different sites in Kolkata city. This bound has later been used to generate the random \(V_{\mathrm{S}}\) profiles using the Monte Carlo simulation. Equivalent linear site response analysis has been performed to study the response of those generated profiles under different input motion excitations. Strong-to-weak ground motion records have been used for this purpose. The amplification spectra of the generated \(V_{\mathrm{S}}\) profiles using all soil types and specific soil-type \(V_{\mathrm{S}}\)–N correlations show significant variations. The study also shows that the \(V_{\mathrm{S}}\)–N correlation may result in quite different \(V_{\mathrm{S},30}\) values and subsequently it may lead to the different site classes according to the NEHRP 2003 classification. So, the random choice of the \(V_{\mathrm{S}}\)–N correlation, where the direct measurement of \(V_{\mathrm{S}}\) is not available, may affect the outcome of seismic hazard analysis significantly. The study points out the need for accurate estimation of the \(V_{\mathrm{S}}\) profile either from in-situ determination or using site-specific correlation. 相似文献
60.
B. L. Sahu S. Ramteke K. P. Rajhans K. S. Patel I. Wysocka I. Jaron 《Water Resources》2018,45(6):992-1001
The ponds are natural water resources used for drinking, bathing, washing and aqua culture. In this work, the contamination of ponds lied in central India with F– and heavy metals (As, Sb, Cr, Mn, Fe, Cu, Zn, Cd, Pb, Th and U) is described. The F– concentration in the pond water and sediment (n = 24) was ranged from 1.6–5.5 mg/L and 210–1430 mg/kg with mean value of 2.3 ± 0.4 mg/L and 599 ± 137 mg/kg, respectively. The concentration variation and sources of the elements in the pond water and sediment are discussed. The health hazards of F– in the domestic animals are described. 相似文献