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171.
Images can contain chemical information and many chemical methods can generate image data. For anefficient extraction of chemical data from images, data analysis techniques are necessary, It is a greatadvantage to be able to work on multivariate images. Many imaging techniques allow the extraction ofchemical information. Inorganic analytical chemistry seems to have the longest tradition here, butorganic chemistry and biochemistry may soon be catching up. Also large data arrays from non-imagingtechniques can be combined with image analysis in a useful way, provided certain conditions are fulfilled.  相似文献   
172.
正1.Overview SPARC(Stratosphere-Troposphere Processes and their Role in Climate)is one of the core projects of the World Climate Research Program(WCRP),coordinating international efforts to address relevant issues in climate and climate prediction via better understanding of the stratosphere-troposphere system.SPARC is a broad umbrella body that  相似文献   
173.
A new method of treating maximum wave height as a random variable in reliability analysis of breakwater caissons is proposed. The maximum wave height is expressed as the significant wave height multiplied by the so-called wave height ratio.The proposed wave height ratio is a type of transfer function from the significant wave height to the maximum wave height.Under the condition of a breaking wave, the ratio is intrinsically nonlinear. Therefore, the probability density function for the  相似文献   
174.
The Twentieth Century Reanalysis (20thCR) dataset released in 2010 covers the period 1871-2010 and is one of the longest reanalysis datasets available worldwide. Using ERA-40, ERA-Interim and NCEP-NCAR reanalysis data, as well as HadSLP2 data and meteorological temperature records over eastern China, the performances of 20thCR in reproducing the spatial patterns and temporal variability of the East Asian winter monsoon (EAWM) are examined. Results indicate that 20thCR data: (1) can accurately reproduce the most typical configuration patterns of all sub-factors differences in the main circulation fields over East Asia involved in the EAWM system, albeit with some in comparison to ERA-40 reanalysis data; (2) is reliable and stable in describing the temporal variability of EAWM since the 1930s; and (3) can describe the high-frequency variability of EAWM better than the low-frequency fluctuations, especially in the early period. In conclusion, caution should be taken when using 20thCR data to study interdecadal variabilities or long-term trends of the EAWM, especially prior to the 1930s.  相似文献   
175.
Using a computational fluid dynamics(CFD)model,the effects of street-bottom and building-roof heating on flow in three-dimensional street canyons are investigated.The building and street-canyon aspect ratios are one.In the presence of street-bottom heating,as the street-bottom heating intensity increases,the mean kinetic energy increases in the spanwise street canyon formed by the upwind and downwind buildings but decreases in the lower region of the streamwise street canyon.The increase in momentum due to buoyancy force intensifies mechanically induced flow in the spanwise street canyon.The vorticity in the spanwise street canyon strengthens.The temperature increase is not large because relatively cold above-roof-level air comes into the spanwise street canyon.In the presence of both street-bottom and building-roof heating,the mean kinetic energy rather decreases in the spanwise street canyon.This is caused by the decrease in horizontal flow speed at the roof level,which results in the weakening of the mean flow circulation in the spanwise street canyon.It is found that the vorticity in the spanwise street canyon weakens.The temperature increase is relatively large compared with that in the street-bottom heating case,because relatively warm above-roof-level air comes into the spanwise street canyon.  相似文献   
176.
Abstract: To determine the geochemical characteristics of the Imgok creek impacted by acid mine drainage (AMD) generated from the abandoned Youngdong coal mine in Korea, chemical analyses of water samples and precipitates and the geochemical modelling of the precipitates were conducted. Acid mine drainage drained from the mine adit and coal refuse piles shows a low pH, high conductivity and high concentrations of Fe, Al, SO4 and heavy metals such as Co, Cu, Ni and Zn. In the Imgok creek, the concentrations of heavy metals and major cations besides Fe are decreased by dilution, but concentrations of Fe are decreased by the formation of precipitates as well as dilution. From the results of geochemical modelling, goethite is oversaturated, and schwertmannite is the most stable solid phase in the Imgok creek. Yellowish red Fe-precipitates collected at the Imgok creek are recognized as amorphous or poorly crystallized minerals from XRD patterns and Feox/Fetotratios, and as containing chemically bonded SO4 and OH by an IR analysis. The mole ratios of Fe/S in these precipitates, which are determined by EPMA, are 5. 1 and 6. 1.  相似文献   
177.
地体基底建造的甄别和表征是联结华北克拉通与朝鲜半岛早期演化历史的基本纽带。针对朝鲜半岛前寒武纪基底建造研究方面的薄弱环节,本文表征了冠帽地块清津地区银德洞出露的变质深成侵入杂岩。3个代表性样品的SIMS锆石U-Pb定年结果显示,早期中性片麻岩记录的岩浆侵入年龄为约2.53 Ga,晚期钾长花岗质片麻岩记录的岩浆侵入年龄为约2.51 Ga,表明银德洞变质杂岩形成于新太古代晚期。参考变质杂岩的岩石地球化学特征,其原岩组成可能包括石英闪长岩和钾长花岗岩,大体上可与全球典型的岩浆型紫苏花岗岩系列相类比。结合3个样品变化较大的锆石εH f(t)值(-1.7~+10.5),我们推测银德洞变质侵入杂岩可能形成于玄武质下地壳岩石的部分熔融及其后的结晶分异作用,代表了活动大陆边缘岩浆弧环境下的典型产物。银德洞变质杂岩归属于新太古代岩浆弧根部岩浆岩建造的研究认识,不仅为判定冠帽地块与华北克拉通东部的吉南和龙地块以及辽北清原地块之间的亲缘性提供了岩石学证据,而且暗示这些地块在新太古代共同处在一个类似于安第斯活动大陆边缘的构造环境。  相似文献   
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