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111.
The bearing capacity of shallow foundations in a non-homogeneous soil profile has been a challenging task in geotechnical
engineering. In this paper, a limit equilibrium method is used for calculating bearing capacity factors of shallow foundations
constructed on a two-layered granular soil profile. The main objective has been to determine the ultimate bearing capacity
computed from equivalent bearing capacity factors Nq and Nγ and comparing that with numerical analysis using finite element methods. It will be shown that the data obtained form the
developed method are well comparable with those obtained from FE approach, specially when the difference between shear strength
parameters of layers is low which is a practical case for sedimentary soil profiles and also for artificially compacted soils.
A computer program has been developed to investigate the influence of various parameters on bearing capacity factors. 相似文献
112.
Ocean Science Journal - Metal concentrations were measured in predominant coastal fauna of the Caspian Sea including six macro-invertebrates (Mnemiposis leidyi, Balanus improvisus, Pontogammarus... 相似文献
113.
The paper presents results of a study on the harmonic response of piles and pile groups embedded in a halfspace to various forms of seismic waves. These include the Rayleigh wave as well as obliquely incident P, SV and SH waves. The pertinent mixed boundary value problems of pile-soil-pile interaction are solved by a numerical model of the boundary integral nature. All modes of foundation vibrations, i.e. translational, rocking and torsional, are included in the model. The results presented are used to highlight the salient features of the seismic response of piles. In addition, the influence of certain pile-soil parameters, such as pile rigidity and pile spacing, on the seismic behaviour of pile foundations is investigated. 相似文献
114.
Consider the problem of estimating the Quasar Luminosity Function (QLF). In a 2007 Ph.D. dissertation, Hugeback considers the QLF as a nonhomogeneous poisson process and estimates the intensity function under SDSS DR3 data (The University of Chicago, AAT 3273021). The present study follows Hugeback’s approach but introduces a mixture component which improves Hugeback’s model in several respects. Namely, the database is partitioned into two groups according to redshift: z < 2.75 and z ? 2.75. Next, a mixture model for the QLF was derived using the concept of pseudolikelihood, the addition of a K function to allow for inter-point interaction, and evaluation of residuals diagnostic plots. This mixture model (i) improves the deviance of Hugeback’s model, and (ii) satisfies residual assumptions that are violated under Hugeback’s model. Moreover, this study confirms Hugeback’s finding of inhomogeneity in the QLF, and provides stronger evidence for the existence of an interaction between redshift and absolute magnitude. 相似文献
115.
Maziar Veyskarami Amir Hossein Hassani Mohammad Hossein Ghazanfari 《Computational Geosciences》2018,22(1):329-346
The network modeling approach is applied to provide a new insight into the onset of non-Darcy flow through porous media. The analytical solutions of one-dimensional Navier-Stokes equation in sinusoidal and conical converging/diverging throats are used to calculate the pressure drop/flow rate responses in the capillaries of the network. The analysis of flow in a single pore revealed that there are two different regions for the flow coefficient ratio as a function of the aspect ratio. It is found that the critical Reynolds number strongly depends on the pore geometrical properties including throat length, average aspect ratio, and average coordination number of the porous media, and an estimation of such properties is required to achieve more reliable predictions. New criteria for the onset of non-Darcy flow are also proposed to overcome the lack of geometrical data. Although the average aspect ratio is the main parameter which controls the inertia effects, the effect of tortuosity on the onset of non-Darcy flow increases when the coordination number of media decreases. In addition, the higher non-Darcy coefficient does not essentially accelerate the onset of inertial flow. The results of this work can help to better understand how the onset of inertial flow may be controlled/changed by the pore architecture of porous media. 相似文献
116.
Lithology and Mineral Resources - The use of key beds in the cap rocks of the oil reservoirs is crucial. Lack of awareness of these key beds will have serious risks and damages. The Gachsaran oil... 相似文献
117.
Amir M. Abdolahzadeh Benoit Lacroix Vachon Alexandre R. Cabral 《Geotechnical and Geological Engineering》2011,29(5):783-802
One important step in the design of inclined covers with capillary barrier effect (CCBE) is the determination of the water
diversion length (DL). Numerical simulations can predict the DL more precisely than steady-state analytical solutions. Nevertheless,
as simplified methods have always been part of engineering design, the application of analytical solutions with conservative
boundary conditions, may allow engineers to make reasonable predictions, particularly during the pre-feasibility stage of
a project. In this study, a CCBE was designed, constructed and instrumented at the Saint-Tite-des-Caps landfill, Quebec, Canada.
This CCBE included a seepage control layer superimposing a sand-gravel capillary barrier. The seepage control layer was made
up of deinking by-products (DBP), an industrial by-product that was previously disposed of as waste. The capillary barrier
was designed using an adaptation of the Ross analytical solution and the scenario considered was that of steady-state flow
during constant seepage flow applied uniformly at the top of the sand-gravel capillary barrier. Although these conditions
appear simplistic, they were deemed reasonable because placement of the seepage control layer on the top of the capillary
barrier led to very low suctions at the interface, thereby allowing uniform downward seepage rates, limited by the saturated
hydraulic conductivity of the DBP. In this paper, a discussion about the behaviour of the cover system based on 4 years of
field data from several instruments is presented. The challenge of using DBP, more precisely the settlement of the DBP layer
and its impact on k
sat
, is also assessed. The DL was reassessed considering the new k
sat
. A discussion on the validity of employing analytical solutions to determine DL is also presented. This paper illustrates
how certain variables affect the design of inclined CCBEs that include a highly compressible material as seepage control layer. 相似文献
118.
Pakistan is located at the cross-roads of plate boundaries, experiencing multiple hazards of earthquake, flood, drought, water-logging, salinization and recurrent landslides. This paper examines the causes and environmental impacts of frequently occurring landslide hazards in the Murree area of Pakistan??s Himalayan region. These are wide ranging in nature and in terms of the damage that result. The area under research was divided into eight blocks and randomly data collected. It was observed that landslides mostly occur along the road network and disturbed slopes. Immature geology, a wide variation in climate and degradation of the natural resource-base were found to be some of the causal factors responsible for the landslide hazards. During the past three decades, rapid expansion of urban zones contributed to the changing vulnerability of the area. The analysis revealed that a large majority of the households (75%) in the area have been directly or indirectly affected by landslide hazards. Damages to already scarce agricultural land, infrastructure and other properties are each year a regular and escalating phenomenon. Landslide size, frequency and consequent costs of damage have increased considerably. 相似文献
119.
120.