全文获取类型
收费全文 | 133篇 |
免费 | 4篇 |
国内免费 | 2篇 |
专业分类
测绘学 | 4篇 |
大气科学 | 1篇 |
地球物理 | 18篇 |
地质学 | 46篇 |
海洋学 | 9篇 |
天文学 | 56篇 |
综合类 | 1篇 |
自然地理 | 4篇 |
出版年
2019年 | 1篇 |
2018年 | 7篇 |
2017年 | 5篇 |
2016年 | 3篇 |
2014年 | 6篇 |
2013年 | 7篇 |
2012年 | 3篇 |
2011年 | 7篇 |
2010年 | 7篇 |
2009年 | 6篇 |
2008年 | 3篇 |
2007年 | 4篇 |
2006年 | 4篇 |
2005年 | 4篇 |
2004年 | 1篇 |
2003年 | 1篇 |
2002年 | 1篇 |
2001年 | 4篇 |
1999年 | 1篇 |
1998年 | 3篇 |
1997年 | 2篇 |
1996年 | 1篇 |
1993年 | 3篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 3篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 4篇 |
1986年 | 1篇 |
1985年 | 8篇 |
1984年 | 5篇 |
1983年 | 7篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1980年 | 3篇 |
1979年 | 2篇 |
1976年 | 1篇 |
1974年 | 3篇 |
1973年 | 1篇 |
1972年 | 2篇 |
1971年 | 1篇 |
1966年 | 1篇 |
1965年 | 1篇 |
排序方式: 共有139条查询结果,搜索用时 46 毫秒
41.
Summary This paper deals with the determination of subsidence parameters on a sloping ground surface above a completely mined underground panel in an inclined seam. A rays projection method is analytically developed to derive the subsidence components on the sloping ground surface from the corresponding ones on an assumed equivalent horizontal surface through the point of the mean elevation of the sloping surface above the extracted panel. Using the derived equations, the variation of subsidence with the inclination of the ground surface is analysed. An example is given to illustrate the application of the rays projection method in predicting subsidence effects on a sloping surface. 相似文献
42.
Subroto Kumar Bhattacharyya V.G. Idichandy Nitindra R. Joglekar 《Applied Ocean Research》1985,7(1):24-34
Load-out, launching and upending are major sequential installation operations of the offshore steel jackets. Due to vital engineering importance of these high risk operations, a thorough scientific understanding of their mechanics is desirable and a physical simulation approach using scaled models is a powerful method to achieve this end. This paper presents such an approach in the context of a case study which is oriented towards gaining adequate understanding of the modelling principles, model design and simulation of operations. It also highlights the role of decisive parameters as they affect the operational performance. Some of the experimental techniques of interest are also presented. 相似文献
43.
In this paper the gravitational collapse of cosmic gas clouds and formation of star clusters has been considered. Hoyle's view of successive fragmentation has been taken as the basic mechanim in the present work. The initial masses of protostars have been estimated as the function of their distances from the centre of the cluster and the intensity of the magnetic field of the medium. It has been shown that the fragmentation process is greatly inhibited by the presence of a strong magnetic field. A model has been constructed showing how a protostar grows in mass by accretion from the surrounding medium, on the basis of the assumption that as the star moves at random in the cluster it picks up a fraction of the material through which it passes. It has been estimated that a protostar of initial mass of about 0.1M
grows to one of 1.0M
in a time period which ranges from a few multiples of 105 to a few multiples of 107 yr, depending on the parameters involved in the accretion process. The number of stars per unit mass range has also been estimated; it is found to be proportional tom
–3.3,m being the mass of the star. 相似文献
44.
45.
Sudip Bhattacharyya 《中国天文和天体物理学报》2010,10(3)
We report an indication(3.22 σ)of ≈ 1860Hz quasi-periodic oscillations from a neutron star low-mass X-ray binary 4U 1636-536.If confirmed,this will be by far the highest frequency feature observed from an accreting neutron star system,and hence could be very useful in understanding such systems.This plausible timing feature was observed simultaneously with lower(≈ 585Hz)and upper(≈ 904Hz)kilohertz quasi-periodic oscillations.The two kilohertz quasi-periodic oscillation frequencies had a ratio of ≈ 1.5,and t... 相似文献
46.
Rabindra Kumar Bhattacharyya 《Pure and Applied Geophysics》1976,114(4):639-646
Summary The body wave propagation in granular medium is discussed in two sections. In Section I, the solutions of general equations of granular medium involving displacement vector and rotation vector are shown to be dependent on the solutions of four different equations. In Section II, the plane wave propagation is studied, showing the dispersion and dissipation of body waves in the granular medium. 相似文献
47.
Phosphate sorption and desorption experiments were conducted with four ferruginous soils (alfisols) of Eastern India, in view of the low native phosphate concentrations in tropical Indian soils. From the P-isotherm curve, standard P requirement (SPR) of the soils was determined. Phosphate sorption data were fitted to both Langmuir and Freundlich equations and mean sorption maximum values obtained for the different soil series were in the decreasing order as Matimahal > Anandapur > Mrigindih > Kashipur. The fraction of added P sorbed followed the same trend as SPR, P sorption maximum (Pmax), phosphate affinity constant (K), maximum phosphate buffering capacity (MPBC), Freundlich constant K′ and phosphate desorption values. Phosphate sorption maximum was significantly correlated with MPBC, Freundlich 1/n, SPR, clay and different forms of Fe and Al. The value of K (bonding energy) was significantly correlated with MPBC, Freundlich K′ and pyrophosphate extractable Fe and Al. The MPBC was significantly correlated with Freundlich K′, Freundlich constant 1/n, clay, oxalate and dithionite extractable, amorphous and crystalline form of Fe and Al. Freundlich K′ was significantly correlated with Freundlich 1/n, pHwater, clay, dithionite extractable and crystalline form of Fe and Al. The results suggested that the soils having higher amount of extractable and reactive Fe and Al shared higher P sorbtion capacity and such soils may need higher levels of P application 相似文献
48.
In this study, ERS-1 altimeter data over the Indian offshore have been processed for deriving marine geoid and gravity. Processing
of altimeter data involves corrections for various atmospheric and oceanographic effects, stacking and averaging of repeat
passes, cross-over correction, removal of deeper earth and bathymetric effects, spectral analyses and conversion of geoid
into free-air gravity anomaly. Methods for generation of residual geoid and free-air gravity anomaly using high resolution
ERS-1 168 day repeat altimeter data were developed. High resolution detailed geoid maps, gravity anomaly and their spectral
components have been generated over the Indian offshore using ERS-I altimeter data and ARCGIS system. A number of known megastructures
over the study area have been successfully interpreted e.g. Bombay High, Saurastra platform, 90° east ridge etc. from these
maps. 相似文献
49.
J. Bhattacharyya 《Pure and Applied Geophysics》1998,153(2-4):399-417
—We study the frequency- and time-domain techniques which have been used to measure shear attenuation in the mantle using long-period body waveforms. In the time-domain technique, waveform modeling is carried out and the attenuation model that best fits the data is chosen. In the frequency-domain technique, we solve for the attenuation model that best fits the spectra of the seismic waveforms. Though theoretically both these techniques are equivalent, modeling assumptions and measurement biases associated with each technique can give rise to different results. In this study, we compare these two techniques in terms of their accuracy in obtaining mantle shear attenuation. Specifically, we estimate the biases in constraining attenuation from differential SS?S and absolute S waveforms. We carry out these tests using realistic synthetic seismograms and we follow this with an analysis of recorded data to verify the results from the synthetic tests. For the SS?S waveforms, the primary biasing factors are interference with seismic phases due to mantle discontinuities and due to crustal reverberation under the SS bounce point. These factors can affect the t* measurements by up to 0.5 s in the frequency domain and more than 1.5 s in the time domain. For the S waveforms, the frequency-domain measurements are accurate to 0.3 s while the time-domain measurements can vary by more than 2.0 s from the predicted values. These errors are also manifested in the t* measurements made using teleseismically recorded waveforms and lead to comparatively larger noise levels in the time-domain measurements. Based on these results, we propose that in long-period body-wave attenuation studies, frequency-domain techniques should be the method of choice. 相似文献
50.
J. C. Bhattacharyya 《Astrophysics and Space Science》1986,118(1-2):45-49