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191.
Summary Annual cyclone and anticyclone numbers in addition to the temperature data for the northern hemisphere are processed through
simple models leading to meaningful interpretations. Historical climatological characteristics of the cyclone and anticyclone
numbers are modeled by a first order Markov process. Statistically indistinguishable synthetic cyclone and anticyclone numbers
are generated. Polygon diagrams which show the mutual relationships between average cyclone (anticyclone) numbers and the
temperature are employed for finding possible relevant climatological changes during the record period. A polygon diagram
concept is proposed and applied in order to identify sub-period warming and cooling spells of any desired short or long term
durations and their relationship to the annual number of cyclone (anticyclone) occurrence numbers. The results indicate a
decrease (increase) in the cyclone and anticyclone numbers during cooling (warming) periods. The methodologies proposed in
this paper can be easily adopted for cyclone and anticyclone numbers modeling in any part of the world.
Received July 15, 1997 Revised January 22, 1999 相似文献
192.
Summary Degree-days as a measure of accumulated temperature deviations from a base temperature have many practical applications in
various human related activities such as home cooling, heating, plant growth in agriculture and power generation in addition
to energy requirement. Long temperature records are necessary for their reliable estimations at given stations. In this paper,
degree-day measure has been applied to monthly temperature records for systematically changed base temperature values from
− 25 °C to + 35 °C with 5 °C increments at 255 meteorology stations in Turkey. The results are represented in the form of
spatial degree-day distribution maps, which are then related to various climatic, meteorological and topographic features
of Turkey. For instance, free surface water bodies in forms of surrounding seas, lakes and rivers insert retardation in the
expansion of heating degree-days over large regions. On the other hand, cold air penetration from polar regions in the northeastern
Turkey originating from Siberia appears at moderate base temperature heating degree-days.
Received August 20, 1998 Revised June 21, 1999 相似文献
193.
The attenuation of seismic waves reflects the elastic nature of the media within which the waves propagate. In this study, we calculate the Coda-Q(Q_c), frequency dependence(η), Vp/Vs and Poisson's(υ) ratios by using 2621 vertical component seismograms generated by 987 earthquakes recorded by 13 seismic stations in Eastern Anatolia, and creat a 2-D seismic tomographic Q_c model for the region. The obtained model provides significant information for exploring the boundaries of adjacent tectonic units within the upper crust and interpreting their dynamic characteristics. The 2-D Q_c model and the other parameters are consistent with the seismotectonic features of Eastern Anatolia. Highly heterogeneous Q_c values are observed in the study area dividing it into north-south directed bands of low and high attenuation. The highest η values were obtained beneath the northwestern and eastern parts of the study region. Clear, high and low υ values are obtained in the western and eastern parts of the study area, respectively. The spatial variations in the measured parameters are consistent with many geophysical observations including low Pn velocities, efficient Sn blockage, high heat flow, and widespread volcanism. Different upper crustal thicknesses and inhomogeneous stress distribution along the East and North Anatolian Fault Zones may also contribute to the observed heterogeneities. 相似文献
194.
Toxic effects of five commonly used pesticides on the biomass of a municipal activated sludge system were determined on the basis of the reduction in the oxygen uptake rate (OUR) and specific oxygen uptake rate (SOUR). Toxicity levels of the selected pesticides were determined by employing a modified OECD 209 (Organisation for Economic Cooperation and Development) method which was performed as batch experiments using a respirometer. Copper sulphate (CuSO4 · 5 H2O), copper oxychloride (Cu2Cl(OH)3), copper calcium oxychloride (CaCu3Cl2(OH)6) as copper‐based pesticides and chlorsulphuron (C12H12ClN5O4S), 2,4‐dichlorophenoxyacetic acid (2,4‐D) (C8H6Cl2O3) as synthetic organic pesticides were selected for the experiments. The EC50 values were determined to be 78, 249 and 281 mg/L for CuSO4 · 5 H2O, Cu2Cl(OH)3 and CaCu3Cl2(OH)6, respectively. Corresponding values for C12H12ClN5O4S and 2,4‐D were 860 and 3664 mg/L, respectively. Results indicated that toxicity effects of copper‐based pesticides were higher than that of synthetic organic pesticides. CuSO4 · 5 H2O was found to exert the highest toxicity among the copper‐based pesticides, whereas, C12H12ClN5O4S was determined to be the most toxic among the organic pesticides on activated sludge biomass. 相似文献