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61.
An objective classification analysis was performed on a water quality data set from 25 sites collected monthly during 1994-2003. The water quality parameters measured included: TN, TON, DIN, NH4+, NO3-, NO2-, TP, SRP, TN:TP ratio, TOC, DO, CHL A, turbidity, salinity and temperature. Based on this spatial analysis, Biscayne Bay was divided into five zones having similar water quality characteristics. A robust nutrient gradient, driven mostly by dissolved inorganic nitrogen, from alongshore to offshore in the main Bay, was a large determinant in the spatial clustering. Two of these zones (Alongshore and Inshore) were heavily influenced by freshwater input from four canals which drain the South Dade agricultural area, Black Point Landfill, and sewage treatment plant. The North Bay zone, with high turbidity, phytoplankton biomass, total phosphorus, and low DO, was affected by runoff from five canals, the Munisport Landfill, and the urban landscape. The South Bay zone, an embayment surrounded by mangrove wetlands with little urban development, was high in dissolved organic constituents but low in inorganic nutrients. The Main Bay was the area most influenced by water exchange with the Atlantic Ocean and showed the lowest nutrient concentrations. The water quality in Biscayne Bay is therefore highly dependent of the land use and influence from the watershed.  相似文献   
62.
63.
The Tarim River Basin is a special endorheic arid drainage basin in Central Asia, characterized by limited rainfall and high evaporation as common in deserts, while water is supplied mainly by glacier and snow melt from the surrounding mountains. The existing drought indices can hardly capture the drought features in this region as droughts are caused by two dominant factors (meteorological and hydrological conditions). To overcome the problem, a new hybrid drought index (HDI), integrating the meteorological and hydrological drought regimes, was developed and tested in the basin in the work. The index succeeded in revealing the drought characteristics and the ensemble influence better than the single standardized precipitation index or the hydrological index. The Artificial Neural Network approach based on temperature and precipitation observations was set up to simulate the HDI change. The method enabled constructing scenarios of future droughts in the region using climate simulation of the GCMs under four RCP scenarios from the latest CMIP5 project. The simulations in the study have shown that the water budget patterns in the Tarim River Basin are more sensitive to temperature than to precipitation. Dominated by temperature rise causing an accelerating snow/glacier melt, the frequency of drought months is projected to decrease by about 14% in the next decades (until 2035). The drought duration is expected to be shortened to 3 months on average, with the severity alleviated. However, the region would still suffer more severe droughts with a high intensity in some years. The general decrease in drought frequency and intensity over the region in the future would be beneficial for water resources management and agriculture development in the oases. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   
64.
Roman mortars were collected from the Villa dei Quintili in Rome, an archaeological site consisting of numerous edifices from nine construction phases dating from the 2nd century A.D. to modern times. A multianalytical approach was used on 34 mortar samples to infer the evolution of production techniques over time and to identify the source area of calcareous raw materials used in the preparation of the lime. Optical microscopy, scanning electron microscopy coupled with an energy‐dispersive system, and laser ablation inductively coupled plasma mass spectrometry were used to study the samples. The major and trace element data were compared with the compositions of two types of limestone samples (Calcare Massiccio and Calcare Maiolica) collected from the Cornicolani Mountains. The results suggest that the technological practices and the calcareous raw materials used for lime production remained unchanged over the time period considered (2nd century A.D. to 3rd century A.D.). The compositions of lime‐related particles in the mortars match those of Calcare Maiolica, which suggests its use as raw material for lime production. On the whole, the results are in agreement with data from existing literature regarding both the use by Roman builders of specific raw materials for the mortars’ production and the relative supply area.  相似文献   
65.
Assessing the environmental impact due to consumption of goods and services is a pivotal step towards achieving the sustainable development goal related to responsible production and consumption (i.e. SDG 12). Household appliances plays a crucial role and should be assessed in a systemic manner, namely considering all life cycle stages, technological efficiency, and affluence aspects. The present study assess the impact of such household appliances used in Europe, and tests scenarios of potential impact reduction at various scales. Life cycle assessment is applied to 14 different household appliances (ranging from dishwashers to television devices) selected to build a set of representative products, based on their economic value and diffusion in households in Europe. Related impacts are calculated with the Environmental Footprint method for calculating a Consumer Footprint “appliances” for the baseline year 2010. A number of scenarios encompassing eco-solutions on a technical level, changes in consumption pattern, behavioral changes, as well as the combination of all these aspects are run to estimate the Consumer Footprint related to household appliances for the year 2030, compared against this baseline scenario. The baseline Consumer Footprint is confirming the importance of the use phase in leading the impacts in almost all impact categories. Testing different scenarios concludes that there is a reduction of the impact for most of the categories (with up to 67% for the ozone depletion potential, and still around 35% for the global warming potential), while two of the here examined impact categories (i.e. land-use and mineral resource depletion) show an overall potential that is even negative – i.e. the results of all scenarios are higher than the ones of the 2010 baseline scenario. The increase in purchase and use of such appliances may offset energy efficiency benefits in some of the examined categories. Hence, the assessment of sustainability of appliances consumption should always include several scales, from the efficiency of the products (micro scale), to the improvement of the energy mix (meso scale), up to accounting for socio-economic drivers and patterns of consumption affecting the overall appliances stock (macro scale).  相似文献   
66.
A detailed reconstruction of the morphology and recent tectonic activity of the Northern Ionian basin is provided on the basis of newly acquired high-resolution swath bathymetric and single and multichannel seismic profiles. The tectonic domains in this area are the Calabrian accretionary wedge and the Apulian foreland. The contact between the two domains, oriented NW–SE, morphologically coincides with a sea-bottom erosional channel (Taranto canyon) characterized on both sides by mass movements induced by slope instability. Along the accretionary wedge/Apulian foreland boundary three different morphological sectors have been recognized whose main characters are represented by a southward stepped increase of erosional canyon activity resulting in a pronounced slope acclivity and a superficial sediment instability. By means of seismic data we correlate the morphology of the sea-bottom to different contractional and flexural processes of the accretionary wedge/foreland system. The interaction between the different rheological domains in the subduction/collision processes could have also induced horizontal stress represented by areas of tectonic release. In an area like this, where very few detailed surveys have been carried out, this study represents the first attempt in correlating the recent tectonic activity to the morphological features and in locating possible slope instability that has to be evaluated for the positioning of offshore infrastructures.  相似文献   
67.
A general increase in precipitation has been observed in Germany in the last century, and potential changes in flood generation and intensity are now at the focus of interest. The aim of the paper is twofold: a) to project the future flood conditions in Germany accounting for various river regimes (from pluvial to nival-pluvial regimes) and under different climate scenarios (the high, A2, low, B1, and medium, A1B, emission scenarios) and b) to investigate sources of uncertainty generated by climate input data and regional climate models. Data of two dynamical Regional Climate Models (RCMs), REMO (REgional Model) and CCLM (Cosmo-Climate Local Model), and one statistical-empirical RCM, Wettreg (Wetterlagenbasierte Regionalisierungsmethode: weather-type based regionalization method), were applied to drive the eco-hydrological model SWIM (Soil and Water Integrated Model), which was previously validated for 15 gauges in Germany. At most of the gauges, the 95 and 99 percentiles of the simulated discharge using SWIM with observed climate data had a good agreement with the observed discharge for 1961–2000 (deviation within ±10 %). However, the simulated discharge had a bias when using RCM climate as input for the same period. Generalized Extreme Value (GEV) distributions were fitted to the annual maximum series of river runoff for each realization for the control and scenario periods, and the changes in flood generation over the whole simulation time were analyzed. The 50-year flood values estimated for two scenario periods (2021–2060, 2061–2100) were compared to the ones derived from the control period using the same climate models. The results driven by the statistical-empirical model show a declining trend in the flood level for most rivers, and under all climate scenarios. The simulations driven by dynamical models give various change directions depending on region, scenario and time period. The uncertainty in estimating high flows and, in particular, extreme floods remains high, due to differences in regional climate models, emission scenarios and multi-realizations generated by RCMs.  相似文献   
68.
Climate change is expected to have substantial impacts on flow regime in the Upper Yellow River (UYR) basin that is one of the most important biodiversity hotspots in the world. These impacts will most possibly exert negative effects on the habitat availability for riverine species. Thus, it is necessary to understand the alteration of river flow regime under climate scenarios. In this paper, we use the modified hydrological model HBV in conjunction with three general circulation models under three representative concentration pathways (RCP 2.6, 4.5, and 8.5) to address changes in flow regime under climate change for the UYR basin in the mid-term (2050s) and end-term (2080s) of the twenty-first century. Flow regime is quantified using the Indicators of hydrological alteration approach. Thereafter, the potential threats to riverine ecosystem in the UYR basin are identified based on the projected alterations of various flow characteristics and their ecological influences. The results showed that the magnitude of monthly flow would increase during the dry period. The date of the annual 1-day minimum streamflow will likely shift toward earlier time under different scenarios, and significant increases in magnitude of annual minimum flow of different durations were detected under both RCP 4.5 and 8.5 scenarios in the 2080s. In addition, assessments of the modification degree of the overall flow regime revealed that climate change would remarkably modify (medium level) the overall flow regime in the UYR basin, particularly by the end of the twenty-first century or under the high emission scenarios. Besides, destruction of habitat and reduced availability of food induced by substantially increased hydrological instability in the 2080s would make two endangered fishes more vulnerable in the UYR basin. These findings provide insights into potential adaptive countermeasures for water resource management and environmental system restoration in the Upper Yellow River.  相似文献   
69.
Assessing the environmental impact due to consumption of goods and services is a pivotal step towards achieving the sustainable development goal related to responsible production and consumption (i.e. SDG 12). Household appliances plays a crucial role and should be assessed in a systemic manner, namely considering all life cycle stages, technological efficiency, and affluence aspects. The present study assess the impact of such household appliances used in Europe, and tests scenarios of potential impact reduction at various scales. Life cycle assessment is applied to 14 different household appliances (ranging from dishwashers to television devices) selected to build a set of representative products, based on their economic value and diffusion in households in Europe. Related impacts are calculated with the Environmental Footprint method for calculating a Consumer Footprint “appliances” for the baseline year 2010. A number of scenarios encompassing eco-solutions on a technical level, changes in consumption pattern, behavioral changes, as well as the combination of all these aspects are run to estimate the Consumer Footprint related to household appliances for the year 2030, compared against this baseline scenario. The baseline Consumer Footprint is confirming the importance of the use phase in leading the impacts in almost all impact categories. Testing different scenarios concludes that there is a reduction of the impact for most of the categories (with up to 67% for the ozone depletion potential, and still around 35% for the global warming potential), while two of the here examined impact categories (i.e. land-use and mineral resource depletion) show an overall potential that is even negative – i.e. the results of all scenarios are higher than the ones of the 2010 baseline scenario. The increase in purchase and use of such appliances may offset energy efficiency benefits in some of the examined categories. Hence, the assessment of sustainability of appliances consumption should always include several scales, from the efficiency of the products (micro scale), to the improvement of the energy mix (meso scale), up to accounting for socio-economic drivers and patterns of consumption affecting the overall appliances stock (macro scale).  相似文献   
70.
Water inflows are a major challenge in tunnelling and particularly difficult to predict in geological settings consisting of heterogeneous sedimentary rock formations with complex tectonic structure. For a high-speed railway line between Bologna and Florence (Italy), a series of seven railway tunnels was drilled through turbiditic formations, ranging from pelitic rocks with thin arenitic layers over sequences including thick-bedded sandstone to calcareous rocks showing chemical dissolution phenomena (karstification). The tunnels were built as draining tunnels and caused significant impacts, such as drying of springs and base-flow losses at mountain streams. A comprehensive hydrological monitoring programme and four multi-tracer test were done, focusing on four sections of the tunnel system. The tracer tests delivered unprecedented data on groundwater flow and transport in turbiditic aquifers and made it possible to better characterize the differential impacts of tunnel drainage along a geological gradient. The impact radius is 200 m in the thin-bedded sequences but reaches 2.3–4.0 km in calcareous and thick-bedded arenitic turbidites. Linear flow velocities, as determined from the peaks of the tracer breakthrough curves, range from 3.6 m/day in the thin-bedded turbidites to 39 m/day in the calcareous rocks (average values from the four test sites). At several places, discrete fault zones were identified as main hydraulic pathways between impacted streams and draining tunnels. This case shows that ignoring the hydrogeological conditions in construction projects can cause terrible damage, and the study presents an approach to better predict hydraulic impacts of draining tunnels in complex sedimentary rock settings.  相似文献   
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