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201.
土壤背景值反映了一定范围内自然环境与人类活动作用下元素指标含量的本底值。依据宁夏固原地区1∶25 万土地质量地球化学调查取得的2 638件土壤样品,利用遍历循环迭代剔除和统计分析方法,得到了研究区表层土壤中53项元素的地球化学背景值和特征参数。通过与中国表层土壤丰度对比,发现研究区Cd、S含量明显高于全国表层土壤丰度,但处于安全限值内; 不同地貌类型下的元素含量差异不仅受成土母质、成壤环境等外部自然条件的影响,也反映了人类活动对土壤环境的扰动。研究可为农业可持续开发与合理利用提供较为可靠的数据支撑。 相似文献
202.
The geostatistical approach was applied to integrate MT (Magneto-telluric) resistivity data and borehole information for the spatial RMR (Rock Mass Rating) evaluation. Generally, resistivity of the subsurface is believed to be positively related to the RMR, thus the resistivity and borehole RMR information was combined in a geostatistical approach. To relate the two different sets of data, the MT resistivity data were used as secondary information and the RMR mean values were estimated at unsampled points by identification of the resistivity to the borehole data. Two types of approach are performed for the estimation of RMR mean values. Then the residuals of the RMR values around the borehole sites are geostatistically modeled to infer the spatial structure of difference between real RMR values and estimated mean values. Finally, this geostatistical estimation is added to the previous means. The result applied to a real situation shows prominent improvements to reflect the subsurface structure and spatial resolution of RMR information. 相似文献
203.
204.
Geochemical Atlas of Slovakia and examples of its applications to environmental problems 总被引:2,自引:0,他引:2
S. Rapant D. Bodiš K. Vrana V. Cvečková J. Kordík K. Krčmová I. Slaninka 《Environmental Geology》2009,57(1):99-110
Results of comprehensive geochemical mapping and thematic studies of the Slovak territory (rocks, soils, stream sediments,
groundwaters, biomass, and radioactivity) in the first half of the 1990s led to several new research programmes in Slovakia,
within the frame of which new methodologies for geochemical data evaluation and map visualization were elaborated. This study
describes the application and elaboration of data from the Geochemical Atlas of the Slovak Republic at national and regional
levels. Based on the index of environmental risk (IER = ΣPEC/PNEC), the level of contamination for the geological component of the environment in Slovakia was evaluated. Approximately
10.5% of Slovakia’s territory was characterized as being environmentally disturbed to highly disturbed. In the areas where
environmental loadings have accumulated, 14 regions where environmental risks existed due to high element concentrations were
defined. The model calculations of health risk estimates based on the databases of the Geochemical Atlas for groundwater and
soils indicate that the possible risk occurrence of carcinogenic diseases from groundwater arsenic contents is high in more
than 10% of Slovakia, whereas the chronic risk is negligible. To determinate the background and threshold levels a combined
statistical–geochemical approach was developed and applied as an example for groundwater at the national level as well as
for single groundwater bodies. The results of statistical method application for the whole groundwater body (GBW) were compared
with the background values for anthropogenically non-influenced areas in GBW. Final background value took into account time
variations and spatial distribution of the element in GBW. Furthermore, based on the database from the Geochemical Atlas for
groundwater, groundwater bodies potentially at qualitative risk were delineated for the whole of Slovakia. From a total of
101 groundwater bodies 17 were characterized as being at risk and 22 as being at possible risk. 相似文献
205.
206.
当前我国没有钛铁矿化学成分标准物质,只有与其相似的钒钛磁铁矿石标准物质,国外钛铁矿标准样品主要是钛铁矿精矿,不能有效地进行分析质量控制,因此迫切急需研制钛铁矿化学成分标准物质。本文研制了5个钛铁矿化学成分标准物质。样品采自山东省莒县棋山钛铁矿矿区、山东省沂水常庄钛铁矿矿区和河北省承德黑山钛铁矿矿区,采用流化床对撞式气流粉碎磨将样品细碎至粒度小于50μm,混合均匀后进行均匀性和稳定性检验,代表性元素的电感耦合等离子体发射光谱和电感耦合等离子体质谱分析结果表明方差检验的F值小于临界值,样品均匀性良好;所检验的元素经18个月6次分析,均未发现统计学意义的明显变化,样品的短期和长期稳定性良好;烘样温度(20~60℃)对亚铁(FeO)的稳定性并无影响,亚铁不会发生氧化。选择11家具有资质的实验室,采取经典分析方法与现代仪器分析技术相结合的方式,选用两种以上不同原理的准确度高的可靠方法对该标准物质联合定值,依照JJF 1343—2012和一级标准物质技术规范,5个钛铁矿化学成分标准物质给出了46项组分(包括主量、痕量和全部稀土元素)的认定值和不确定度,TiO2的含量范围为2.97%~19.76%,TFe的含量范围为18.88%~51.30%,基本涵盖了我国钛铁矿成矿类型,能够满足钛铁矿勘查、评价和开发的需求。 相似文献
207.
208.
生态文明与城市绿色发展要解决的问题本质上来说是正确处理人与自然之间的关系。生态文明是建设新时代中国特色社会主义和构建人类命运共同体的战略思想。城市绿色发展是转变人类社会发展模式,实现可持续发展的战略措施。两者之间有着鲜明的时代发展耦合特征,根据发展时序和中国经济社会发展阶段性特征,分为三个发展阶段:初期理论研究与实践探索阶段、逐渐上升为国家行动与理论体系建设阶段和国家行动的全面深化与理论体系的建立阶段。在城市绿色发展过程中,人通过以土地要素为主的生态空间和以产业为主的社会经济活动对自然产生影响,使城市发展在经济系统上实现绿色增长,在自然生态系统上提高绿色财富,在社会系统上提升绿色福利。城市绿色发展的基本思路:在城市发展进程中要始终坚持生态文明的理念,全面推进城市绿色发展;坚持城市空间规划先行方针;大力推进产业结构绿色升级和发展绿色新业态;强化环境保护和生态修复;实施基础设施绿色升级改造和推进绿色基础设施建设;加快制定完善城市绿色发展政策措施。 相似文献
209.
F. Lorenzo A. Alonso M. J. Pellicer J. L. Pagés M. Pérez-Arlucea 《Environmental Geology》2007,52(4):789-802
This research focuses on the development of metal pollution in sediment cores from three estuaries in Northwest Spain: Viveiro,
Ortigueira and Barqueiro. Pb, Cu, Co, Cr, Cd and Zn and total organic carbon were assessed using principal component analysis
(PCA) in order to obtain background values, measure pollution levels and identify pollution sources. Results were interpreted
by considering the local industrial history, grain size and C/N relationship. The pollution levels obtained bear a strong
resemblance to those documented for of a moderately industrialised area. PCA identifies factors that reflect mainly temporal
associations with metals. Sedimentation rates between 0.9 and 1.1 cm/year were determined. In Viveiro core levels of Cr pollution
are associated with tanneries. In Ortigueira, high core levels of Cu and Co are linked to mining, and Cr levels to adjacent
ultramafic rocks. Erosion of Holocene sediment causes high values of Co and Cr in the Barqueiro core. Cu increase in the three
estuaries is related to fungicide use since 1910. Sea level rise appears to be affecting the marine characteristics of the
sediments in Barqueiro. In Viveiro, the nature of the sediment reflects engineering work and land reclamation. 相似文献
210.
通过对三组含不同粒度成分的无泥型软弱层带室内土动三轴试验, 表明阻尼比有随动应变增加而增大的趋势, 但粒度成分和含水状态又对阻尼比产生不同的影响。分析显示, 以粗碎屑为特征的无泥型软弱层带对地震动荷载的反应程度可初步认为应属于不明显的土, 即其动力学性质变化 (衰减幅度)较松散~中等密实的饱和砂土要小。 相似文献