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31.
Several different inventories of global and regional anthropogenic and biomass burning emissions are assessed for the 1980?C2010 period. The species considered in this study are carbon monoxide, nitrogen oxides, sulfur dioxide and black carbon. The inventories considered include the ACCMIP historical emissions developed in support of the simulations for the IPCC AR5 assessment. Emissions for 2005 and 2010 from the Representative Concentration Pathways (RCPs) are also included. Large discrepancies between the global and regional emissions are identified, which shows that there is still no consensus on the best estimates for surface emissions of atmospheric compounds. At the global scale, anthropogenic emissions of CO, NOx and SO2 show the best agreement for most years, although agreement does not necessarily mean that uncertainty is low. The agreement is low for BC emissions, particularly in the period prior to 2000. The best consensus is for NOx emissions for all periods and all regions, except for China, where emissions in 1980 and 1990 need to be better defined. Emissions of CO need better quantification in the USA and India for all periods; in Central Europe, the evolution of emissions during the past two decades needs to be better determined. The agreement between the different SO2 emissions datasets is rather good for the USA, but better quantification is needed elsewhere, particularly for Central Europe, India and China. The comparisons performed in this study show that the use of RCP8.5 for the extension of the ACCMIP inventory beyond 2000 is reasonable, until more global or regional estimates become available. Concerning biomass burning emissions, most inventories agree within 50?C80%, depending on the year and season. The large differences between biomass burning inventories are due to differences in the estimates of burned areas from the different available products, as well as in the amount of biomass burned.  相似文献   
32.
Mountain regions are sensitive to climate changes, which make them good indicators of climate change. The aim of this study is to investigate the spatial and temporal variability of air temperature and precipitation in the Polish Carpathians. This study consists of climatological analyses for the historical period 1851-2010 and future projections for 2021-2100. The results confirm that there has been significant warming of the area and that this warming has been particularly pronounced over the last few decades and will continue in the oncoming years. Climate change is most evident in the foothills; however, these are the highest summits which have experienced the most intensive increases in temperature during the recent period. Precipitation does not demonstrate any substantial trend and has high year-to-year variability. The distribution of the annual temperature contour lines modelled for selected periods provides evidence of the upward shift of vertical climate zones in the Polish Carpathians, which reach approximately 350 meters, on average, what indicates further ecological consequences as ecosystems expand or become extinct and when there are changes in the hydrological cycle.  相似文献   
33.
Ocean Science Journal - The abundance of bacteria inhabiting the sediment-water interface and their taxonomic composition were determined with the fluorescence in situ hybridization (FISH) method...  相似文献   
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The effect of different concentrations of sodium chloride on the metabolic activity of halophilic bacteria derived from the Lake Gardno estuary was studied using respirometric methods. The influence of salt was examined in two ways: the bacteria were preincubated in various concentrations of sodium chloride, and the cells used for respirometric measurements were supplied with substrates dissolved in water amended with various concentrations of the salt. Generally, an increase in the concentration of sodium chloride in the medium used for preincubation resulted in an increase in metabolic activity. Conversely, a decrease was noted when solutions of increasing salt content were employed to dissolve the substrate. The decrease in oxygen uptake noted when increased amounts of salt were added is proposed to be the result of the short period allowed for adaptation of cells to the higher salt concentrations.  相似文献   
36.
Two runs of a large-eddy simulation model with Deardorff's and Schumann's subgrid parametrizations have been compared in order to analyze spurious effects at the top of the mixed layer due to a presence of a strong temperature jump. Simulations performed showed that Schumann's subgrid eddy viscosity was sufficient to spreads out sharp ripples which appeared in the numerical solution due to numerical dispersion. Deardorff's subgrid eddy viscosity was found too small near the top of the mixed layer, and as a result truncation dispersion errors caused unphysical solutions in this region.  相似文献   
37.
Abstract

This paper makes use of a water balance study of a mountainous area with a wide range of average annual rainfall in an arid and semiarid region to illustrate the development of both a statistical model of daily rainfall and a rainfall-runoff model. The models are appropriate for these conditions and may be relevant to similar areas. Comparisons of mean rainfall and runoff at the arid end of the scale suggest that runoff coefficients do not conform to common assumptions.  相似文献   
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Microstructure of Turbulence in the Stably Stratified Boundary Layer   总被引:1,自引:1,他引:0  
The microstructure of a stably stratified boundary layer, with a significant low-level nocturnal jet, is investigated based on observations from the CASES-99 campaign in Kansas, U.S.A. The reported, high-resolution vertical profiles of the temperature, wind speed, wind direction, pressure, and the turbulent dissipation rate, were collected under nocturnal conditions on October 14, 1999, using the CIRES Tethered Lifting System. Two methods for evaluating instantaneous (1-sec) background profiles are applied to the raw data. The background potential temperature is calculated using the “bubble sort” algorithm to produce a monotonically increasing potential temperature with increasing height. Other scalar quantities are smoothed using a running vertical average. The behaviour of background flow, buoyant overturns, turbulent fluctuations, and their respective histograms are presented. Ratios of the considered length scales and the Ozmidov scale are nearly constant with height, a fact that can be applied in practice for estimating instantaneous profiles of the dissipation rate.  相似文献   
40.
Based on the daily observational precipitation data at 147 stations in the Yangtze River Basin during 1960–2005 and projected daily data of 79 grid cells from the ECHAM5/ MPI-OM model in the 20th and 21st century, time series of precipitation extremes which contain AM (Annual Maximum) and MI (Munger Index) are constructed. The distribution feature of precipitation extremes is analyzed based on the two index series. Three principal results were obtained, as stated in the sequel. (i) In the past half century, the intensity of extreme heavy precipitation and drought events was higher in the mid-lower Yangtze than in the upper Yangtze reaches. Although the ECHAM5 model still can’t capture the precipitation extremes over the Yangtze River Basin satisfactorily, spatial pattern of the observed and the simulated precipitation extremes are much similar to each other. (ii) For quantifying the characteristics of extremely high and extremely low precipitation over the Yangtze River Basin, four probability distributions are used, namely: General Extreme Value (GEV), General Pareto (GPA), General Logistic (GLO), and Wakeby (WAK). It was found that WAK can adequately describe the probability distribution of precipitation extremes calculated from both observational and projected data. (iii) Return period of precipitation extremes show spatially different changes under three greenhouse gas emission scenarios. The 50-year heavy precipitation and drought events from simulated data during 1951–2000 will become more frequent, with return period below 25 years, for the most mid-lower Yangtze region in 2001–2050. The changing character of return periods of precipitation extremes should be taken into account for the hydrological design and future water resources management.  相似文献   
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