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371.
本文根据我国台湾海洋工作者的调查分析资料,对台湾近海的温、盐垂直分布及t-S图解特征进行分析,按其相似性特点进行归类和分型,并探讨它们的特点和异同之处。主要结果如下:1.冬、夏季台湾近海的温、盐垂直分布类型有5种,t-S图解类型为9种。2.冬季台湾近海的水温垂直分布存在着一层、二层、三层结构,夏季多为三层结构;冬、夏季的盐度垂直分布为二层和三层结构。3.台湾西南、南和东北近海,t-S图解类型复杂,出现多种类型交错。4.夏季台湾南端的猫鼻头、鹅銮鼻沿岸附近,其温、盐垂直分布皆出现上均匀层,此现象实属少见。 相似文献
372.
本文根据经济贝类污染物残留量调查结果,对辽宁沿岸海域贻贝、菲律宾蛤仔作为重金属、石油污染的生物指示种的可能性进行了初步研究和评价。应用POLYDIV统计技术对采自辽宁沿岸海域14个站点样品中的重金属、石油含量进行了统计分析,结果表明辽宁沿岸海域各站点的贻贝、菲律宾蛤仔受Cu,Zn,Cd,Hg和石油污染与石油污染程度的分布和沿岸排放工业废水的分布及表层沉积物中的含量相一致。据此,贻贝和菲律宾蛤仔可作为监测Cu,m,Cd,Hg和石油污染的生物指示种;可否作为Pb的生物指示种尚需进一步研究。 相似文献
373.
This study has tested the following main hypotheses. (1) The composition of fish assemblages in nearshore waters along the lower west coast of Australia will differ significantly among four habitat types (1–4), which could be distinguished quantitatively from each other by differences in the values for a statistically selected suite of enduring environmental variables. (2) The extents of the differences in ichthyofaunal composition among the four habitat types will statistically match those in the suite of environmental variables that distinguish those habitat types. A 60.5 m long seine net, with 9 mm mesh in the bunt, was used seasonally for 2 years to sample fish from sites representing each of the four nearshore habitat types, which differed broadly in their exposure to wave activity and the extent and location of seagrass beds. The compositions of the fish faunas in each habitat type were significantly different from each other in all but one case. Ichthyofaunal composition did not differ significantly between years in any habitat type and differed significantly among seasons in only one habitat type. The arrangement of the rank orders of similarity in matrices constructed from the abundances of the fish species at each site also did not differ between years but did differ among seasons. Moreover, the arrangement of the ranks in the similarity matrices produced from the ichthyofaunal data recorded at the various sites in each season were significantly correlated with that in the distance matrix constructed from the environmental data for those sites, with the correlation (ρ) ranging from 0.476 in winter to 0.696 in autumn. These results thus demonstrate that the extents of the differences in the fish compositions among the various habitat types parallel those in the environmental data for the corresponding habitat types. The subset of species that provided the best correlation with the environmental distance matrix, and which was thus most responsible for distinguishing among the fish compositions at the four habitat types, was also determined for each season. 相似文献
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377.
J.G. Ferreira A.M. Nobre T.C. Simas M.C. Silva A. Newton S.B. Bricker W.J. Wolff P.E. Stacey A. Sequeira 《Estuarine, Coastal and Shelf Science》2006,66(3-4):468-482
A methodology is developed and tested for division of estuarine and coastal systems into water bodies for monitoring and management purposes. This division is often implicit in the choice of sampling stations and in pollution abatement measures applied to different locations – it is now an explicit requirement of European Union Directive 2000/60/EC (Water Framework Directive) and recommended by United States Agencies such as EPA and NOAA. The approach considers both natural characteristics and the human dimension, by means of a stepwise methodology, which considers, on the one hand, morphology and salinity distribution, and, on the other, appropriate indicators of pressure and state. In the present application, nitrogen and phosphorus loading was used as the pressure component and chlorophyll a and dissolved oxygen as indicators of state. The criteria for system division were defined based on (1) an adimensional shape factor and salinity classes for the natural component; and (2) a normalised pressure index and (ASSETS) eutrophication symptom classes for the human dimension. Water quality databases and GIS were used to develop spatial distributions for the various components, and the results were aggregated into a final water body division, using tidal excursion as a “common sense” test. The methodology was applied to three well-studied systems in Portugal, a tubular estuary (Mondego), a wide lagunal estuary (Sado) and a coastal barrier island system (Ria Formosa). Although a final definition of water bodies will usually be a policy decision, this type of approach for the division of coastal systems into management units scientifically informs the decision-making process. 相似文献
378.
Nitrogen and Phosphorus Diffusive Fluxes Across the Sediment-Water Interface in Estuarine and Coastal Tidal Flats 总被引:1,自引:0,他引:1
Nitrogen and phosphorus contents are analyzed in the overlying waters and pore waters taken from the Changjiang Estuary and Shanghai coastal tidal flats in this study. In addition, the diffusion fluxes of nitrogen and phosphorus across the sediment-water interface in tidal flats are estimated according to the nutrient concentration gradients at the interface. It has been indicated that the concentrations of ammonium, nitrite, nitrate and dissolved phosphorus in overlying waters range from 0.0082~2.56, 0.03~0.58, 0.69~5.38 and 0.035~0.53 mg/L, respectively, while 0.0025 ~ 1.35 mg/L for NH4+-N, 0. 0055 ~ 0.20mg/L for NO2--N, 0.61~1.14 mg/L for NO3--N and 0.11~0.53mg/L for DP insurface pore waters.The findings have revealed that ammonium, nitrite, nitrate and dissolved phosphorus diffusion fluxes across the sediment-water interface are between -0.024~0.99, -0.39~ -0.0019, -3.09~the source of phosphorus and an important sink for nitrogen in the waters. 相似文献
379.
P. W. Balls 《Estuarine, Coastal and Shelf Science》1985,20(6):717-728
Dissolved cadmium and copper concentrations have been determined in 76 surface water samples in coastal and ocean waters around Scotland by anodic stripping voltammetry (ASV). A trace metal/salinity ‘front’ is observed to the west, north and north-east of Scotland separating high salinity ocean water (>35 × 10−3) with low concentrations of dissolved Cd and Cu from lower salinity (<35 × 10−3) coastal water containing higher concentrations of Cd and Cu. Mean Cd concentrations in ocean and coastal waters are 7 ng dm−3 (0·06 n
) and 11 ng dm−3 (0·10 n
) respectively; for Cu the respective levels are 60 ng dm−3 (0·95 n
) and 170 ng dm−3 (2·68 n
). The observed distribution is attributed principally to freshwater runoff and the advection of contaminated Irish Sea water into the study area. 相似文献
380.
舟山海区几种藤壶的食性分析 总被引:1,自引:0,他引:1
舟山海区五种藤壶的食性成分分析表明:其胃含物可分为浮游动物、浮游植物、有机碎屑及无机颗粒四类。浮游动物以挠足类为主,浮游植物以硅藻为主。不同大小个体的藤壶摄食偏向有所差别:大个体藤壶较多地摄食大型的烧足类等浮游动物,而小个体藤壶较多地摄食小型的硅藻等浮游植物和有机碎屑。藤壶食物成分种类与其生活海区中的浮游生物种类相一致,并随海区中浮游生物种类和数量变化而变化。通过测定发现,分布于外海的三角藤壶的食物颗粒度明显大于近海虾塘中的纹藤壶的食物颗粒度。 相似文献