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71.
Summary Torsional vibration of a body composed of two conical bars, the upper one being made of non-homogeneous material and the lower of a homogeneous material, by the application of a shearing stress on the upper end has been considered in the problem. It is assumed that the lower end of the composite body is fixed and the lateral surface is free from shearing stress. 相似文献
72.
D. Chatterjee 《Pure and Applied Geophysics》1970,82(1):34-40
Summary The expressions for stresses and extension have been obtained in an isotropic circular cylinder in a state of plane strain, the elastic constants and the density of the material varying exponentially and the results have been compared with those in the homogeneous case. 相似文献
73.
Niranjan D. Chatterjee 《Contributions to Mineralogy and Petrology》1970,27(3):244-257
The mineral paragonite, NaAl2[AlSi3O10 (OH)]2, has been synthesized on its own composition starting from a variety of different materials. Indexed powder data and refined cell parameters are given for both the 1M and 2M1 polymorphs obtained. The upper stability limit of paragonite is marked by its breakdown to albite + corundum + vapour. The univariant equilibria pertaining to this reaction have been established by reversing the reaction at six different pressures, the equilibrium curve running through the following
intervals: 1 kb: 530°–550° C 2 kb: 555°–575° C 3 kb: 580°–600° C 5kb: 625°–640° C 6 kb: 620°–650° C 7 kb: 650°–670° C.Comparison with the upper stability limit of muscovite (Velde, 1966) shows that paragonite has a notably lower thermal stability thus explaining the field observation that paragonite is absent in many higher grade metamorphic rocks in which muscovite is still stable.The enthalpy and entropy of the paragonite breakdown reaction have been estimated. Since intermediate albites of varying structural states are in equilibrium with paragonite, corundum and H2O along the univariant equilibrium curve, two sets of data pertaining to the entropy of paragonite (S
298
0
) as well as the enthalpy ( H
f,298
0
) and Gibbs free energy ( G
f,298
0
) of its formation were computed, assuming (1) high albite and (2) low albite as the equilibrium phase. The values are: (1) (2) S
298
0
67.8±3.9 cal deg–1 gfw–1 63.7±3.9 cal deg–1 gfw–1
H
f,298
0
–1417.9±2.7 kcal gfw–1 –1420.2±2.6 kcal gfw–1
G
f,298
0
–1327.4±4.0 kcal gfw–1 –1328.5±4.0 kcal gfw–1.Adapted from a part of the author's Habilitationsschrift accepted by the Ruhr University, Bochum (Chatterjee, 1968). 相似文献
74.
B.K. Chatterjee 《Sedimentary Geology》1983,34(4):307-314
The transmission electron microscope has been used to study the ultrafabric changes and crystal growth during incipient metamorphism (eometamorphism) of a shallow-water microcrystalline Kolhan limestone, Singhbhum district, Bihar. The eometamorphosed limestone is characterized by gradual increase in crystal size, abrupt changes from curvilinear boundaries to strain-induced planar triple junctions, transgranular microcracks and glide planes. The textural details like growth lines, intergranular microcracks and microporosity, and fluid inclusions commonly associated with early neomorphosed limestones have been progressively eliminated by eometamorphism. 相似文献
75.
The non‐stationary rocking response of liquid storage tanks under seismic base excitations including soil interaction has been developed based on the wavelet domain random vibration theory. The ground motion has been characterized through statistical functionals of wavelet coefficients of the ground acceleration history. The tank–liquid–foundation system is modelled as a multi‐degree‐of‐freedom (MDOF) system with both lateral and rocking motions of vibration of the foundation. The impulsive and convective modes of vibration of the liquid in the tank have been considered. The wavelet domain coupled dynamic equations are formulated and then solved to get the expressions of instantaneous power spectral density function (PSDF) in terms of functionals of input wavelet coefficients. The moments of the instantaneous PSDF are used to obtain the stochastic responses of the tank in the form of coefficients of hydrodynamic pressure, base shear and overturning base moment for the largest expected peak responses. Parametric variations are carried out to study the effects of various governing parameters like height of liquid in the tank, height–radius ratio of the tank, ratio of total liquid mass to mass of foundation, and shear wave velocity in the soil medium, on the responses of the tank. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
76.
In this paper, we have attempted a diagnostic study of the turbulence characteristics of the ABL by means of two one-dimensional models. The first model uses a first order non-local closure, based on the Transilient Turbulence Theory, for parameterizing turbulent fluxes. while the second model uses second order local closure for parameterizing these. The models have been applied to conduct case studies using the Kytoon data taken at Kharagpur, during 17th–21st June, 1990, as part of the MONTBLEX programme. Our findings bring out various interesting features regarding the non-local and local turbulent statistics such as kinematic fluxes, turbulence kinetic energy, vertical velocity variance, the contribution of the eddies of various sizes to the fluxes at different level and the mixing lengths. The one-dimensional anisotropy of the turbulent eddies has been revealed by the findings from the transilient model. The vertical variation of the turbulence kinetic energy, as computed directly by the second order model, is found to be strongly correlated with the vertical velocity variance. In particular, for stably stratified boundary layers, identification of two distinct zones of the turbulence kinetic energy and corresponding vertical velocity maxima is possible, which has been interpreted as positive evidence of patchy turbulence in the boundary layer. 相似文献
77.
B. H. Subbaraya K. S. Appu K. P. Chatterjee A. F. Chizhov V. D. Grinchinkov A. Jayaraman G. A. Khokin V. A. Kononkov I. S. Moshnikov V. Narayanan S. P. Perov O. V. Shtrikov Y. V. Somayajulu C. R. Sreedharan K. S. Zalpuri 《Journal of Earth System Science》1987,96(1):25-40
A total of seventeen vertical profiles of ozone were obtained during an Indo-USSR collaborative experiment on ozonesonde intercomparison conducted at Thumba during March 1983. The vertical distribution of ozone was measured using rocket-borne, balloon-borne as well as ground-based instruments. Four different rocket ozonesondes from India and USSR and the balloon ozonesonde were used to makein situ observations of ozone concentrations in addition to the Dobson spectrophotometric observations of total ozone and Umkehr. The rocket and the balloon launchings were effected in three salvos and measurements were made at different times of the day as well as during night. The results of all these measurements are used to obtain a mean ozone vertical distribution over Thumba foT the spring equinoxial period. The mean profile shows the maximum ozone concentration at 27 km with a value of (3.86±0-52)×1012 molecules per cc. Comparison of this mean profile with available satellite data for the equatorial regions shows that, in general, the Thumba values are lower by 10–15% at altitudes below 40 km and larger at altitudes above 50 km compared to the satellite results. The data also show evidence for a day-to-day variability and a possible day-to-night variability in the ozone vertical distribution with the night-time values higher than the daytime values at all altitudes above 35 km and the difference is found to increase with the increasing altitude. 相似文献
78.
Susanne Flux Niranjan D. Chatterjee Klaus Langer 《Contributions to Mineralogy and Petrology》1984,86(3):294-297
Pure, synthetic 2M1-muscovites (Ms) and 2M1-paragonites (Pg) prepared at 7, 13.5, and 18 kbar
have been subjected to careful X-ray powder diffractometry and IR powder spectrometry. The results of X-ray studies show
that the lattice constants of these micas are independent of the pressure employed in synthesizing them. Similarly, the IR
powder spectra of Ms and Pg remain unaffected by the synthesis pressure. Neither the Al[4]-O-Al[4] vibrations decrease in relative intensity nor do the Si-O-Al[4] vibrations increase in intensity with increasing pressure of synthesis, as they should, if pressure-induced (Al, Si)[4] ordering had been operative. Finally, the v
OH bands in Ms and Pg are also found to retain their fine structural details, regardless of the pressures employed in synthesizing
these phases. In particular, the half widths of v
OH in these (Al,Si)[4]-disordered micas remain constant at around 60 cm−1, compared to ∼ 10 cm−1 in (Al,Si)[4]-ordered mica margarite.
In the light of this study, shortening of the b lattice parameter and progressive (Al,Si)[4] ordering with increasing pressure of synthesis of muscovites reported by Velde (1980) would appear to be anomalous. Consequently,
any discussion of the effect of (Al,Si)[4] ordering on the stability of muscovite is a moot point at present. 相似文献
79.
Somdev Bhattacharji Rajesh Sharma Nilanjan Chatterjee 《Journal of Earth System Science》2004,113(4):771-784
The western continental margin and the intraplate Narmada-Tapti rifts are primarily covered by Deccan flood basalts. Three-dimensional
gravity modeling of +70mgal Bouguer gravity highs extending in the north-south direction along the western continental margin
rift indicates the presence of a subsurface high density, mafic-ultramafic type, elongated, roughly ellipsoidal body. It is
approximately 12.0 ±1.2 km thick with its upper surface at an approximate depth of 6.0 ±0.6 km, and its average density is
{dy2935} kg/m3. Calculated dimension of the high density body in the upper crust is 300 ±30 km in length and 25 ±2.5 to 40 ±4 km in width.
Three-dimensional gravity modeling of +10mgal to -30mgal Bouguer gravity highs along the intraplate Narmada-Tapti rift indicates
the presence of eight small isolated high density mafic bodies with an average density of {dy2961} kg/m3. These mafic bodies are convex upward and their top surface is estimated at an average depth of 6.5 ±0.6 (between 6 and 8km).
These isolated mafic bodies have an average length of 23.8 ±2.4km and width of 15.9 ±1.5km. Estimated average thickness of
these mafic bodies is 12.4±1.2km. The difference in shape, length and width of these high density mafic bodies along the western
continental margin and the intraplate Narmada-Tapti rifts suggests that the migration and concentration of high density magma
in the upper lithosphere was much more dominant along the western continental margin rift. Based on the three-dimensional
gravity modeling, it is conjectured that the emplacement of large, ellipsoidal high density mafic bodies along the western
continental margin and small, isolated mafic bodies along the Narmada-Tapti rift are related to lineament-reactivation and
subsequent rifting due to interaction of hot mantle plume with the lithospheric weaknesses (lineaments) along the path of
Indian plate motion over the Réunion hotspot. Mafic bodies formed in the upper lithosphere as magma chambers along the western
continental margin and the intraplate Narmada-Tapti rifts at estimated depths between 6 and 8 km from the surface (consistent
with geological, petrological and geochemical models) appear to be the major reservoirs for Deccan flood basalt volcanism
at approximately 65 Ma. 相似文献
80.
A Breadth Averaged Numerical Model for Suspended Sediment Transport in Hooghly Estuary,East Coast of India 总被引:2,自引:0,他引:2
Sinha P. C. Guliani Pragya Jena G. K. Rao A. D. Dube S. K. Chatterjee A. K. Murty Tad 《Natural Hazards》2004,32(2):239-255
Sedimentation is of vital concern in the conservation, development and utilization ofour soil and water resources. The suspended sediment in estuarine waters is hazardousto navigation in estuaries, which have important ports and harbours. A breadth-averagednumerical model to study circulation and sediment transport is presented in this paper.The model is applied to Hooghly estuary, along the east coast of India. The model is fullynon-linear and uses a semi-explicit finite difference scheme to solve mass, momentum andadvection diffusion equation for suspended sediments in a vertical plane. The erosion anddeposition have been computed by empirically developed source and sink terms in thesuspended sediment equation. 相似文献