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871.
张北6.2级地震前的卫星热红外异常 总被引:24,自引:0,他引:24
利用张北地震前 1个月华北北部 (37~ 42°N,1 1 3~ 1 1 9°E)的气象卫星 NOAA/ AVHRR热红外遥感资料 ,提取震前热红外温度异常 ,研究其时空变化的过程和特征 ,并对热红外温度异常与地震的关系进行初步的探讨。结果表明 ,在张北地震前 1 3天沿张家口 -渤海断裂带确有显著的热红外温度异常出现。异常区域呈条带状 ,且与 NW向地质构造一致 ;温度异常的动态变化可大致分为初始、平缓发展和临震加速 3个阶段。将热红外温度异常作为一种临震前兆对强震的预报具有一定的映震效应 相似文献
872.
J. Trčková 《Environmental Geology》1998,35(4):245-250
Experimental modelling methods are used for prediction of deformation and groundwater outflows at the bottom of an open-pit
mine during the excavation of brown coal. Thermal gas-bearing artesian water exerts an uplift pressure on the impervious subsoil
of the coal seam and threatens the stability of the mine bottom. The breakthrough of the mine bottom would seriously affect
the groundwater regime and may endanger mining activities. The mining is carried out within the protection zones of the Carlsbad
spa springs. Results of model studies are used to determine protective hydrogeological and mining measures for providing the
maximum protection for the open-pit mine and the spa springs.
Received: 16 August 1996 · Accepted: 9 June 1997 相似文献
873.
本文根据C.A.等(1963。1965)提出的海洋上层温度结构特征的无因次普遍函数,利用1957~1964年暖半年渤海、黄海、东海159个站次连续站的资料和作者(1983)提出的海面热量平衡的简易计算公式计算海面的热量收支,建立了海洋上均匀层厚度、温跃层强度和跃层下界深度的半经验半理论模式。该模式反映了形成海洋上层温度结构特征的主要因子及其作用,同时避开了一般理论模式中的起算点和目前难以获得的物理海洋学参数,而可以直接利用表面水温、气温和风速进行海洋上层温度特征的计算。 相似文献
874.
A geometrical model, including different geometrical shapes influencing thermal conductivity of snow is proposed. The geometrical
model has been assumed to comprise of unit cells having solid (ice) inclusion as an aggregation of spherical, cylindrical
or cubical shapes with vertical connection, arranged in a cubic packing. From the geometrical model and one-dimensional heat
transfer theory, the effective thermal conductivity has been computed. For this purpose, coupled one-dimensional heat transfer
equations have been solved for steady-state condition to account for conduction in ice, conduction in air and latent heat
transfer due to water vapour sublimation through air. The model demonstrates the dependency of thermal conductivity on density,
grain-spacing, grain contact ratio and temperature. Spherical inclusions give highest conductivity while cubical inclusion
estimates lowest value for the same density. Thermal conductivity has been found increasing sharply near to the packing density
for all three shapes. Empirical model results and results obtained from existing microstructure based models have also been
compared with the present model. 相似文献
875.
Aysen Davraz 《Environmental Geology》2008,54(3):615-628
Thermal waters of the Usak area have temperatures ranging from 33 to 63°C and different chemical compositions. These waters
hosted by the Menderes Metamorphic rocks emerge along fault lineaments from two geothermal reservoirs in the area. The first
reservoir consists of gneiss, schists, and marbles of the Menderes Metamorphic rocks. The recorded reservoir is Pliocene lacustrine
limestone. Hydrogeochemical studies indicate that thermal waters were mixed with surface waters before and/or after heating
at depth. The results of mineral equilibrium modeling indicate that all the thermal waters are undersaturated at discharge
temperatures for gypsum, anhydrite, and magnesite minerals. Calcite, dolomite, aragonite, quartz, and chalcedony minerals
are oversaturated in all of the thermal waters. Water from the reservoir temperatures of the Usak area can reach upto120°C.
According to δ18O and δ2H values, all thermal and cold groundwater are of meteoric origin. 相似文献
876.
Geochemical evidence of seawater intrusion into a coastal geothermal field of central Greece: example of the Thermopylae system 总被引:1,自引:0,他引:1
A. Duriez C. Marlin E. Dotsika M. Massault A. Noret J. L. Morel 《Environmental Geology》2008,54(3):551-564
Thermal water of Thermopylae and from other geothermal fields located in the southern part of the Sperchios basin (central
Greece) are characterized by high salinity (total dissolved salts, or TDS, range from 1.2 to 30.3 g L−1) associated with a degassing of CO2. To determine the mineralization processes, geochemical and isotopic investigations (major elements, 18O, 2H and 13C) have been carried out upon 17 thermal waters from springs and boreholes. This study emphasizes that all the thermal waters
result from the mixing of a seawater end-member, several fresh water components depending on the field location, and a mantle-derived
CO2 rising upward through an E–W fault system. The seawater identified in the thermal mixture is likely to be evolved Aegean
seawater (ASW). Once intruded into the basin sediments, the trapped seawater has its chemical content modified by both water–rock
interactions and massive dissolution of the deep CO2 (pCO2 of 100.5 atm). The modelling performed with PHREEQC indicates that the anomalous major ion ratios measured in the so-called evolved
ASW are explained by the dissolution of calcite and dolomitization process associated to precipitation of gypsum within the
thermal aquifer. 相似文献
877.
基于Diviner热红外数据的Apollo 15登陆区元素含量反演 总被引:1,自引:0,他引:1
月球元素含量的反演是了解月球物质成分的分布和月球矿产资源开发利用的依据。通过比较月球样品元素含量与不同粒径样品光谱CF值所建立模型的反演精度,确定10~20μm粒径样品最适用于月表元素含量反演。以Apollo 15登陆点附近为例,利用Diviner热红外数据得到了完整覆盖度和更高分辨率月球CF值影像,反演了月表Al、Fe、Mn、Mg和Ca元素相对含量。与月球样品实测值进行了对比,均方根误差均小于3,验证了利用红外数据反演月表元素相对含量的可行性,为月表元素含量反演提供了新的思路。 相似文献
878.
Significant advances have been achieved in generating soil moisture (SM) products from satellite remote sensing and/or land surface modeling with reasonably good accuracy in recent years. However, the discrepancies among the different SM data products can be considerably large, which hampers their usage in various applications. The bias of one SM product from another is well recognized in the literature. Bias estimation and spatial correction methods have been documented for assimilating satellite SM product into land surface and hydrologic models. Nevertheless, understanding the characteristics of each of these SM data products is required for many applications where the most accurate data products are desirable. This study inter-compares five SM data products from three different sources with each other, and evaluates them against in situ SM measurements over 14-year period from 2000 to 2013. Specifically, three microwave (MW) satellite based data sets provided by ESA's Climate Change Initiative (CCI) (CCI-merged, -active and -passive products), one thermal infrared (TIR) satellite based product (ALEXI), and the Noah land surface model (LSM) simulations. The in-situ SM measurements are collected from the North American Soil Moisture Database (NASMD), which involves more than 600 ground sites from a variety of networks. They are used to evaluate the accuracies of these five SM data products. In general, each of the five SM products is capable of capturing the dry/wet patterns over the study period. However, the absolute SM values among the five products vary significantly. SM simulations from Noah LSM are more stable relative to the satellite-based products. All TIR and MW satellite based products are relatively noisier than the Noah LSM simulations. Even though MW satellite based SM retrievals have been predominantly used in the past years, SM retrievals of the ALEXI model based on TIR satellite observations demonstrate skills equivalent to all the MW satellite retrievals and even slightly better over certain regions. Compared to the individual active and passive MW products, the merged CCI product exhibits higher anomaly correlation with both Noah LSM simulations and in-situ SM measurements. 相似文献
879.
880.
The thermal energy balance and the temperature profile of the Hakone volcano are considered quantitatively. Across the Hakone volcano and its surroundings the heat flow values vary from 10–1 to 103 mW/m2, due to thermal conduction and mass flow involving volcanic steam and hot spring discharge. An area with extremely low heat flow is observed in the western side of the caldera showing the presence of percolating meteoric water. The hydrothermal activity is intense in the eastern half of the caldera.The total heat discharge from the high temperature zone (discharge area) of the Hakone volcano amounts to 11.0×107 W. The magmatic steam energy discharge is 95.0×106 W. The thermal energy by redistribution of the terrestrial heat flow by the lateral deep ground water flow is calculated to be 9.00×106 W. For the model having the vertical vent in the volcano's central part up to 1 km depth below the ground surface from a magma reservoir the computed temperature distribution is consistent with the observed values. The depth of the magma reservoir is 7 km below the ground surface and the diameter is 5 km. 相似文献