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31.
32.
WINDOW FACTOR ANALYSIS:THEORETICAL DERIVATION AND APPLICATION TO FLOW INJECTION ANALYSIS DATA 总被引:1,自引:0,他引:1
EDMUND R.MALINOWSKI 《地理学报(英文版)》1992,(1)
Window factor analysis(WFA)is a self-modeling method for extracting the concentration profiles ofindividual components from evolutionary processes such as flow injection,chromatography,titrationsand reaction kinetics.The method takes advantage of the fact that each component lies in a specificregion along the evolutionary axis,called the‘window’.Theoretical equations are derived.The methodis used to extract the concentration profiles and spectra of seven bismuth species from data obtained byGemperline and Hamilton,who injected bismuth perchlorate into a flowing stream of hydrochloric acid. 相似文献
33.
Biomass Burning in Southern Africa: Individual Particle Characterization of Atmospheric Aerosols and Savanna Fire Samples 总被引:2,自引:0,他引:2
Xiande Liu Piet Van Espen Freddy Adams Jan Cafmeyer Willy Maenhaut 《Journal of Atmospheric Chemistry》2000,36(2):135-155
Ambient atmospheric aerosols and savanna fireparticulate emission samples from southern Africa werecharacterised in terms of particle classes and theirnumber abundance by electron probe X-ray microanalysis(EPXMA). About ten particle classes were identifiedfor each sample. The major classes werealuminosilicates and sea salts for ambient coarse(2–10 m equivalent aerodynamic diameter (EAD))samples, and K-S and S-only particles for ambient fine(<2 m EAD) samples. The K-S particles are oneof the major products of biomass burning. The EPXMAresults were found to be consistent with the resultsfrom bulk analyses on a sample by sample basis. Forsavanna fire fine samples, quantitative EPXMA revealedthat many particles had a composition of simple saltssuch as KCl. Some particles had a deviatingcomposition in the sense that more ionic species wereinvolved in sustaining the balance between cations andanions, and they were composite or mixed salts.Because of extensive processing during the atmospherictransport, the composition of the K-S particles in theambient samples was different from K2SO4,and such particles were enriched with S. The finepyrogenic KCl particles and the fine sea-saltparticles were much depleted in chlorine. 相似文献
34.
采用马弗炉将样品与NaOH混合进行熔融煅烧,热去离子水提取、离心、稀释后过OnGuard Ⅱ H柱和过滤膜进行前处理,抑制型电导离子色谱法检测,测定了Ta2O5和Nb2O5的氟离子、氯离子和硫酸根离子。该方法对三种被测阴离子的检测限(s/N=3)在0.15~0.70μg/g(以固体样品实际浓度计)或0.136~0.623μg/L(以溶液浓度计),标准曲线线性范围均在两个数量级以上,方法的精密度(RSD,n=7)小于5.46%,回收率为88%~106%,具有灵敏度高、选择性好、重现性佳、对环境友好等特点,用于实际样品的检测,结果令人满意。 相似文献
35.
36.
Estimation of groundwater recharge using the chloride mass-balance method, Pingtung Plain, Taiwan 总被引:4,自引:0,他引:4
Due to rapid economic growth in the Pingtung Plain of Taiwan, the use of groundwater resources has changed dramatically.
Over-pumping of the groundwater reservoir, which lowers hydraulic heads in the aquifers, is not only affecting the coastal
area negatively but has serious consequences for agriculture throughout the plain. In order to determine the safe yield of
the aquifer underlying the plain, a reliable estimate of groundwater recharge is desirable. In the present study, for the
first time, the chloride mass-balance method is adopted to estimate groundwater recharge in the plain. Four sites in the central
part were chosen to facilitate the estimations using the ion-chromatograph and Thiessen polygon-weighting methods. Based on
the measured and calculated results, in all sites, including the mountain and river boundaries, recharge to the groundwater
is probably 15% of the annual rainfall, excluding recharge from additional irrigation water. This information can improve
the accuracy of future groundwater-simulation and management models in the plain.
Received, April 1996 Revised, March 1997, November 1997 Accepted, March 1998 相似文献
37.
The application of a modified version of dynamic TOPMODEL for two subcatchments at Plynlimon, Wales is described. Conservative chemical mixing within mobile and immobile stores has been added to the hydrological model in an attempt to simulate observed stream chloride concentrations. The model was not fully able to simulate the observed behaviour, in particular the short‐ to medium‐term dynamics. One of the primary problems highlighted by the study was the representation of dry deposition and cloud‐droplet‐deposited chloride, which formed a significant part of the long‐term chloride mass budget. Equifinality of parameter sets inhibited the ability to determine the effective catchment mixing volumes and coefficients or the most likely partition between occult mass inputs and chloride mass inputs determined by catchment immobile‐store antecedent conditions. Some success was achieved, in as much as some aspects of the dynamic behaviour of the signal were satisfactorily simulated, although spectral analysis showed that the model could not fully reproduce the 1/f power spectra of observed stream chloride concentrations with its implications of a wide distribution of residence times for water in the catchment. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
38.
It is necessary to pay more attention to the durability of concrete undergoing freeze-thaw cycles and seawater attack simultaneously.Investigated are the effects of water-binder ratio,fly ash (FA) contents and air-entraining agent on resistance to frost and chloride diffusion of marine concrete blended with FA in natural seawater.The results show that fly ash does not improve the frost resistance of concrete but can improve its resistance to chloride diffusion by addition of less than 30%.The resistance to frost and chloride diffusion of FA concrete can be improved with the decrease of water-binder ratio,and FA may improve both of them simultaneously only being mixed with air-entraining agent.A ratio (named as R) of the frost-resisting durability factor to chloride diffusion coefficient can be used to evaluate the durability of marine concrete.Scanning electron microscope (SEM) analyses are consistent with the evaluations by the value of R. 相似文献
39.
Chloride is a major anion in soil water and its concentration rises essentially as a function of evapotranspiration. Compared to herbaceous vegetation, high transpiration rates are measured for isolated trees, shelterbelts or hedgerows. This article deals with the influence of a tree hedge on the soil and groundwater Cl? concentrations and the possibility of using Cl? as an indicator of transpiration and water movements near the tree rows. Cl? concentrations were measured over 1 year at different depths in the unsaturated zone and in the groundwater along a transect intersecting a bottomland oak hedge. We observed a strong spatial heterogeneity of Cl? concentrations, with very high values up to 2 g l?1 in the unsaturated zone and 1·2 g l?1 in the upper part of the groundwater. This contrasts with the low and homogeneous concentrations (60–70 mg l?1) in the deeper part of the groundwater. Cl? accumulation in the unsaturated zone at the end of the vegetation season allows us to identify the active root zone extension of trees. In winter, upslope of the tree row, downwards leaching partly renews the soil solution in the root zone, while the slow water movement under the trees or farther downslope results in Cl? accumulation and leads to a salinization of the soil and groundwater. This salinization is of the same order as experimental conditions produce negative effects on oak seedlings. The measurement of Cl? concentrations in the unsaturated zone under tree rows at the end of the vegetation season would indicate whether certain topographic, pedological or climatic conditions are likely to favour a strong salinization of the soil, as observed in the present study. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
40.
Surface sediment samples in the near shore area of the north Shandong Peninsula are collected for grain size and element analyses. The results indicate that the surface sediments in the study area are primarily composed of the silt-sized components similar to the Huanghe River. The total concentration of aluminum varies from 5.57% to7.37%(average(6.33 ± 0.40)%), and its spatial distribution is mainly controlled by the grain size. Correlations between the ratio of aluminum to titanium concentration and aluminum concentration, titanium concentration and the mean grain size indicate that aluminum in the near shore surface sediments is affected majorly by the terrigenous source, and partially by the anthropogenic source. The ratios of aluminum to titanium concentrations are larger than the background value of loess matter at some stations due to the existence of excess aluminum associated with human activities. Thus, the sources of aluminum should be identified firstly when aluminum is used as an index of terrigenous matter even in the near shore area dominated by terrigenous deposits. 相似文献