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641.
The paper presents the results of determination of inorganic and organic forms of phosphorus in bottom sediments of Pomeranian Bay. The sediments were collected in March and July of 1996. The following characteristics of the sediments were determined: organic matter content, forms of inorganic phosphorus: loosely adsorbed phosphorus and phosphorus bound to aluminium, calcium and iron, as well as total inorganic phosphorus. Pomeranian Bay is a shallow basin, with depth averaging between 12 and 15 m and sandy sediments prevailing. Smaller silt fractions occur only in the vicinity of the
wina River estuary and in deeper northern regions of the Bay. Calcium-bound phosphorus is the dominant form of inorganic phosphorus in the Pomeranian Bay. Iron-bound phosphorus is the second most prevailing form, and aluminium-bound phosphorus the third. Loosely bound phosphorus was present in the lowest amounts. Total inorganic phosphorus in the Bay consisted of the four forms listed above, except in estuarine regions where an additional form of phosphorus occurred, most probably occluded phosphorus. High organic phosphorus concentrations were found at the
wina River estuary and in the northern part of the Bay (Saßnitz Deep) corresponding to the higher organic matter content of these sediments. Sediments of Pomeranian Bay contained less phosphorus than those from the Gulf of Gda
sk or Puck Bay and other parts of the Baltic Sea, suggesting that the amount of phosphorus in the sediments was determined by a number of inter-related factors, such as sediment type, amount of organic matter, the chemical composition of the sediment and oxygen content of near-bottom water. 相似文献
642.
Masahide?WakitaEmail author Shuichi?Watanabe Yutaka?W.?Watanabe Tsuneo?Ono Nobuo?Tsurushima Shizuo?Tsunogai 《Journal of Oceanography》2005,61(1):129-139
The dissolved inorganic carbon (DIC) and related chemical species have been measured from 1992 to 2001 at Station KNOT (44°N, 155°E) in the western North Pacific subpolar region. DIC (1.3∼2.3 µ mol/kg/yr) and apparent oxygen utilization (AOU, 0.7∼1.8 µmol/kg/yr) have increased while total alkalinity remained constant in the intermediate water (26.9∼27.3σθ). The increases of DIC in the upper intermediate water (26.9∼27.1σθ) were higher than those in the lower one (27.2∼ 27.3σθ). The temporal change of DIC would be controlled by the increase of anthropogenic CO2, the decomposition of organic matter and the non-anthropogenic CO2 absorbed at the region of intermediate water formation. We estimated the increase of anthropogenic CO2 to be only 0.5∼0.7 µmol/kg/yr under equilibrium with the atmospheric CO2 content. The effect of decomposition was estimated to be 0.8 ± 0.7 µmol/kg/yr from AOU increase. The remainder of non-anthropogenic CO2 had increased by 0.6 ± 1.1 µmol/kg/yr. We suggest that the non-anthropogenic CO2 increase is controlled by the accumulation of CO2 liberated back to atmosphere at the region of intermediate water formation due to the decrease of difference between DIC in the winter mixed layer and DIC under equilibrium with the atmospheric CO2 content, and the reduction of diapycnal vertical water exchange between mixed layer and pycnocline waters. In future, more accurate and longer time series data will be required to confirm our results. 相似文献
643.
644.
Inorganic ions and nutrients were measured at different depths of the Xiangxi and Daninghe Rivers to explore the mixing processes of representative bays in the Three Gorges Reservoir (TGR). HCO3− and Ca2+ are the dominant ions. Carbonate weathering is the most important mechanism controlling the ion water chemistry; however, important differences exist between the main channel and its tributaries. Major ion levels in the TGR bays depend on hydrological mixing. Results show that the major ions of Ca2+, Mg2+, Na+, K+, Sr2+, SO42− and Cl− show chemically conservative behaviour during transit through the bays of the TGR. This means the ions can be used as tracers in the same way that salinity is used in estuaries to explore behaviour of other non‐conservative elements and to indicate specific source waters. In contrast, nutrients are not conserved in the mixing zone. The mixing of the main channel and tributaries and biological utilization in backwater reaches were the key factor controlling nutrient distributions in Xiangxi and Daninghe Bays. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
645.
Concentrations of major ions and the δ13C composition of dissolved inorganic carbon in groundwater and submarine groundwater discharges in the area between Siracusa and Ragusa provinces, southeastern Sicily, representing coastal carbonate aquifers, are presented and discussed. Most of groundwater analysed belongs to calcium bicarbonate type, in agreement with the geological nature of carbonate host rocks. Carbonate groundwater acquires, besides the dissolution of carbonate minerals, dissolved carbon (and the relative isotopic composition) from the atmosphere and from soil biological activity. In fact, δ13C values and total dissolved inorganic carbon contents show that both these sources contribute to carbon dissolved species in the waters studied. Finally, mixing with seawater in the second main factor of groundwater mineralization Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
646.
电感耦合等离子体发射光谱法测定磷矿石中微量有毒元素铅砷镉 总被引:8,自引:6,他引:2
用电感耦合等离子体发射光谱法测定磷矿石中微量有毒元素铅、砷和镉,并对溶样条件及共存元素干扰和仪器工作条件进行了试验。方法检出限为Pb0.042mg/L、As0.053mg/L、Cd0.006mg/L;相对标准偏差为(RSD,n=11)Pb0.86%、As1.36%和Cd1.08%;回收率为Pb109.3%、As94.0%和Cd90.0%。方法用于分析磷矿石标准样品和出口磷矿石检验样,分析结果与其他方法一致,能够满足日常检验的要求。 相似文献
647.
熔融制片-X射线荧光光谱法测定磷矿石中主次量组分 总被引:10,自引:5,他引:5
采用四硼酸锂-偏硼酸锂混合熔剂熔融制备样片,用Axios型X射线荧光光谱仪测定磷矿石样品中五氧化二磷、氟、二氧化硅、三氧化二铝、总三氧化二铁、氧化镁、氧化钙、氧化钠、氧化钾、二氧化钛、氧化锰、氧化锶和硫等13种组分。重点试验了熔样比、熔样温度和标样制备。用基本参数法校正基体效应,分析方法的精密度(RSD,n=10)除二氧化钛、氟和硫分别小于10.8%、6.0%及10.2%外,其余各组分均小于4.5%。用磷矿石国家一级标准物质验证,结果与标准值相符。 相似文献
648.
649.
电感耦合等离子体发射光谱法快速测定磷矿石中主次量组分 总被引:7,自引:3,他引:4
采用碳酸锂-硼酸混合熔剂在高频熔样机上熔融样品酸化定容后,直接用电感耦合等离子体发射光谱法快速测定磷矿石中五氧化二磷、氧化钙、氧化镁、二氧化硅、氧化铁、氧化铝、氧化钾、氧化钠、二氧化钛、氧化锰、氧化锶11种组分的含量,对入射波长、雾化压力、入射功率、提升量等分析条件进行了优化。方法检出限为0.0001~0.019μg/g,相对标准偏差(RSD,n=11)为0.78%~2.60%。建立的方法抗干扰能力强,线性范围宽,精密度高,结果准确,适用于磷矿石中主次量组分的分析。 相似文献
650.
Jan D. Miller Chen-Luh Lin Lukasz Hupka Mohamed I. Al-Wakeel 《International Journal of Mineral Processing》2009,93(1):48-53
Procedures for 3D mineral liberation analysis by X-ray micro CT (XMT) are presented and discussed including the construction of liberation-limited grade/recovery curves for specific feed materials. In this way, actual separation efficiencies can be compared to what might be expected for a perfect separation limited only by the extent of liberation. It is shown that 3D mineral liberation analysis based on XMT is preferred to 2D section analysis which overestimates the extent of liberation. By way of example, procedures and experimental results are presented and discussed for feed material in the case of phosphate rock flotation. 相似文献