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351.
THE SENSITIVITY TEST STUDY OF AIR-SEA SURFACE FLUX MODEL 总被引:2,自引:0,他引:2
In this article, a sensitivity test of air-sea surface flux model was carried out with the field observation data of Project “South China Sea Air-Sea Flux Measurement in 2000”. The results show that sensible heat fluxes are sensitive to observation errors, increasing the error of model calculation; In contrast, the latent heat flux and momentum flux are not as sensitive to observation errors as the sensible heat, and their calculated results are reliable. The test result also verifies… 相似文献
352.
We derive both 3-D and 2-D Fréchet sensitivity kernels for surface-wave group-delay and anelastic attenuation measurements. A finite-frequency group-delay exhibits 2-D off-ray sensitivity either to the local phase-velocity perturbation δ c / c or to its dispersion ω(∂/∂ω)(δ c / c ) as well as to the local group-velocity perturbation δ C / C . This dual dependence makes the ray-theoretical inversion of measured group delays for 2-D maps of δ C / C a dubious procedure, unless the lateral variations in group velocity are extremely smooth. 相似文献
353.
In this study, we test the adequacy of 2-D sensitivity kernels for fundamental-mode Rayleigh waves based on the single-scattering (Born) approximation to account for the effects of heterogeneous structure on the wavefield in a regional surface wave study. The calculated phase and amplitude data using the 2-D sensitivity kernels are compared to phase and amplitude data obtained from seismic waveforms synthesized by the pseudo-spectral method for plane Rayleigh waves propagating through heterogeneous structure. We find that the kernels can accurately predict the perturbation of the wavefield even when the size of anomaly is larger than one wavelength. The only exception is a systematic bias in the amplitude within the anomaly itself due to a site response.
An inversion method of surface wave tomography based on the sensitivity kernels is developed and applied to synthesized data obtained from a numerical simulation modelling Rayleigh wave propagation over checkerboard structure. By comparing recovered images to input structure, we illustrate that the method can almost completely recover anomalies within an array of stations when the size of the anomalies is larger than or close to one wavelength of the surface waves. Surface wave amplitude contains important information about Earth structure and should be inverted together with phase data in surface wave tomography. 相似文献
An inversion method of surface wave tomography based on the sensitivity kernels is developed and applied to synthesized data obtained from a numerical simulation modelling Rayleigh wave propagation over checkerboard structure. By comparing recovered images to input structure, we illustrate that the method can almost completely recover anomalies within an array of stations when the size of the anomalies is larger than or close to one wavelength of the surface waves. Surface wave amplitude contains important information about Earth structure and should be inverted together with phase data in surface wave tomography. 相似文献
354.
三峡库区滑坡灾害与地质环境关系分析 总被引:1,自引:0,他引:1
采用敏感性系数方法分析三峡工程库区滑坡灾害与地质环境各因子不同区段(类型)的关系,以敏感性系数的灾点分析法进行统计分析,得出各因子的不同区段(类型)对滑坡灾害发育的敏感性大小和三峡工程库区斜坡地段滑坡灾害发生的优势地质环境因子组合。 相似文献
355.
根据以往维护水管倾斜仪的一些经验,介绍了在DSQ水管倾斜仪的标定过程中,调整换能器电压灵敏度的一些技巧。 相似文献
356.
D. Ramakrishnan K. K. Mohanty S. R. Nayak R. Vinu Chandran 《Geotechnical and Geological Engineering》2006,24(6):1581-1602
The Bhuj earthquake (Mw = 7.9) occurred in the western part of India on 26th January 2001 and resulted in the loss of 20,000
lives and caused extensive damage to property. Soil liquefaction related ground failures such as lateral spreading caused
significant damage to bridges, dams and other civil engineering structures in entire Kachchh peninsula. The Bhuj area is a
part of large sedimentary basin filled with Jurassic, Tertiary and Quaternary deposits. This work pertains to mapping the
areas that showed sudden increase in soil moisture after the seismic event, using remote sensing technique. Multi-spectral,
spatial and temporal data sets from Indian Remote Sensing Satellite are used to derive the Liquefaction Sensitivity Index
(LSeI). The basic concept behind LSeI is that the near infrared and shortwave infrared regions of electromagnetic spectrum
are highly absorbed by soil moisture. Thus, the LSeI is herein used to identify the areas with increase in soil moisture after
the seismic event. The LSeI map of Bhuj is then correlated with field-based observation on Cyclic Stress Ratio (CSR) and Cyclic
Resistance Ratio (CRR), depth to water table, soil density and Liquefaction Severity Index (LSI). The derived LSeI values
are in agreement with liquefaction susceptible criteria and observed LSI (R
2 = 0.97). The results of the study indicate that the LSeI after calibration with LSI can be used as a quick tool to map the
liquefied areas. On the basis of LSeI, LSI, CRR, CSR and saturation, the unconsolidated sediments of the Bhuj area are classified
into three susceptibility classes. 相似文献
357.
Precise spatial estimation of ore grades and impurity contents from sample data limited in amount and location is indispensable
to metallic and nonmetallic resource exploration. One of the advantages of using geostatistics for this purpose is that it
can incorporate multivariate data into spatial estimation of one variable. However, there are two weak points concerning technical
and post-processing problems. First is the difficulty in application to geologic data in which spatial correlations are not
clear because of intrinsic nonlinear behavior. Second is the absence of indices to interpret the mechanisms and factors which
govern the spatial distribution. To address these problems, a spatial method of modeling based on a feedforward neural network,
SLANS, which recognizes the relationship between the data value and location by considering supplementary attributes such
as lithology and biostratigraphy, and a sensitivity analysis using this network were developed. These methods were applied
to two case studies, genetic mechanisms of kuroko deposits and quality assessment of a limestone mine. The first case study
is a spatial analysis of principal metals of kuroko deposits (volcanogenic massive sulfide deposits) in the Hokuroku district,
northern Japan. It was clarified that upward and downward sensitivity vectors were distinguished near the deposits inside
and outside the tectonic basin, respectively. Sensitivity analysis for the second case study showed a strong effect of crystalline
limestone on the important impurity, P2O5 contents. Hydrothermal alteration, which could cause leaching and secondary concentration of phosphorus, is considered to
have produced this effect. 相似文献
358.
A shallow water tomography scheme based on the modal wave number inversion technique is considered in this paper. The scheme
is based on the assumption that modal wave number for transpped mode can be measured in a suitable way. The tomographic inversion
is accomplished into steps; firstly, the bottom parameter are inverted by using the bottom reflection phase shift with the
known sound speed profile; secondly, the variation of sound speed profile at different time is inverted provided the bottom
parameters are known. A numerical simulation shows that the proposed scheme works well, and the sensitivity analysis of sound
speed profile inversion is performed, for shallow water environmental parameters: sound speed, density and attenuation coefficient
of the bottom. 相似文献
359.
粘土矿物对油气层的损害及防治研究 总被引:15,自引:1,他引:14
粘土矿物的分散运移、膨胀以及酸敏导致沉淀物的生成,都严重地造成了地层孔隙的堵塞,对油气的三次开采造成了很大的危害。本文从粘土矿物的晶体结构入手,对粘土矿物损害油气层的机理进行了初步探讨,并对粘土矿物损害地层的三种方式提出了有效的防治措施,并通过室内实验,找出了有效的合理配方。 相似文献
360.
介绍一种新型机电传感器的工作原理,建立其频率响应特性方程,由幅频及相频特性曲线分析其工作特性。 相似文献