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ABSTRACT: Over 700 community drinking water supplies were sampled for the pesticide Temik (aldicarb and its oxidative metabolites aldicarb sulfoxide and aldicarb sulfone) in Florida. All community supply wells sampled for Temik were located in counties where Temik was reported to have been used and approximately one-half of the wells were located in counties where ground water was determined to be highly susceptible to contamination by Temik. Susceptibility was determined using ranking criteria that incorporated ground water recharge characteristics, water use, and Temik use patterns. Temik was not detected in any of the community supply wells sampled during the study. However, Temik was detected in shallow, private wells, as was the pesticide ethylene dibromide in counties with ground water characterized as highly susceptible to contamination.  相似文献   
33.
Gas emissions were determined for dairy cows fed three diets formulated to represent feed ingredients typical of the Midwest, South, or West regions of the United States. Dairy cows were housed and monitored in 12 environmentally controlled rooms (4 cows diet). Two experiments were performed, representing two lactation stages (initial days in milk were 115 ± 39 d in Stage 1 and 216 ± 48 d in Stage 2). The results demonstrated that the combination of different dietary ingredients resulted in different gas emissions while maintaining similar dry matter intake (DMI) and milk yield (MY). Diet effect on ammonia (NH) emissions was more prominent in Stage 1. During Stage 1, cows fed the Midwest diet had the highest daily NH emission, corresponding to the highest crude protein (CP) concentration among the three regions. The differences in NH emissions (39.0%) were much larger than the percent difference in CP concentrations between diets (6.8%). Differences in N intake, N excretion, or milk urea N alone may not serve as a strong indicator of the potential to reduce NH emissions. Lower emissions of methane (CH) per unit DMI or per unit MY were observed for cows offered the South diet during Stage 1 as compared with that from cows offered the Midwest or West diets. No diet effect was observed for hydrogen sulfide (HS) emission per unit S intake, nor for nitrous oxide (NO) emission. The measured NH and CH emissions were comparable, but the NO emissions were much higher than those reported for tie-stall dairy barns in the literature.  相似文献   
34.
Gaseous and particulate pollutant concentrations associated with five samples per day collected during a July 2001 summer intensive study at the Pittsburgh Carnegie Mellon University (CMU) Supersite were used to apportion fine particulate matter (PM2.5) into primary and secondary contributions using PMF2. Input to the PMF2 analysis included the concentrations of PM2.5 nonvolatile and semivolatile organic material, elemental carbon (EC), ammonium sulfate, trace element components, gas-phase organic material, and NO(x), NO2, and O3 concentrations. A total of 10 factors were identified. These factors are associated with emissions from various sources and facilities including crustal material, gasoline combustion, diesel combustion, and three nearby sources high in trace metals. In addition, four secondary sources were identified, three of which were associated with secondary products of local emissions and were dominated by organic material and one of which was dominated by secondary ammonium sulfate transported to the CMU site from the west and southwest. The three largest contributors to PM2.5 were secondary transported material (dominated by ammonium sulfate) from the west and southwest (49%), secondary material formed during midday photochemical processes (24%), and gasoline combustion emissions (11%). The other seven sources accounted for the remaining 16% of the PM2.5. Results obtained at the CMU site were comparable to results previously reported at the National Energy Technology Laboratory (NETL), located approximately 18 km south of downtown Pittsburgh. The major contributor at both sites was material transported from the west and southwest. Some difference in nearby sources could be attributed to meteorology as evaluated by HYSPLIT model back-trajectory calculations. These findings are consistent with the majority of the secondary ammonium sulfate in the Pittsburgh area being the result of contributions from distant transport, and thus decoupled from local activity involving organic pollutants in the metropolitan area. In contrast, the major local secondary sources were dominated by organic material.  相似文献   
35.
To keep pace with population and economic growth, the city of Hyderabad, India, will need to identify and develop new supply sources almost continually. Increasing population growth rate, declining surface water resources, overexploitation of groundwater, deterioration of ground water quality and poor sewage treatment are the major water-related issues in Hyderabad. This paper reviews the current situation facing policy makers who need to come to terms with the problem of restricted water supply and increasing demand in an urban centre such as Hyderabad, India. The City Water Balance model developed in this study can be used to analyse different scenarios that include water conservation, urban wastewater reuse and improvement of distribution and conveyance efficiency. Water conservation programs, which include a 5% conveyance efficiency improvement, reusing 90 million cubic metres (MCM) of urban runoff and adoption of water harvesting by 0.5 million households together with recycling 120 MCM of wastewater recycling wastewater would be sufficient to meet the water demand by 2031, if the population grows at a rate of 2.5%.  相似文献   
36.
Results with the EPRI 2.5 MW(e) Integrated Environmental Control Pilot Plant (IECPP) indicate the interrelationship of particulate penetration, SO2 scrubber operation, waste production, and waste properties. Tests compared a fabric filter/wet scrubber and ESP/wet scrubber, the latter operated to simulate 1979 New Source Performance Standards (NSPS), 1971 NSPS, and pre-NSPS ESP units. Tests were conducted with low-sulfur coal producing a flue gas concentration of400ppm; flue gas spiking could be used to increase SO2 to 2000 ppm. Scrubber waste was dewatered in a thickener and vacuum belt filter (to 55 percent solids content), and mixed with fly ash. The pilot SO2 scrubber—when preceded by an ESP and forced to operate in zero-discharge—captured less SO2 than when preceded by a fabric filter. Also, scrubber operation with the ESP produced a greater quantity of waste with difficult handling characteristics, as compared to operation with the fabric filter. These difficulties occurred with particulate penetration above 0.10 lb/MBtu, which could reduce reagent utilization to 80percent. These results are attributable to inhibited limestone dissolution due to accumulation of an aluminum/fluoride compound. For both lowsulfur and simulated high-sulfur test conditions, allowing wastewater discharge to purge aluminum/fluoride content restored performance to design levels. Particulate control efficiency also affected solid waste physical properties. The fabric filter/wet scrubber produced the lowest solid waste permeability (10?8 cm/s). ESP operation at 1979 NSPS and pre-1971 NSPS ESPs increased solid waste permeability to 10?7 and 10?6 cm/s, respectively. These results are meaningful for SO2 scrubbers both for new plants and for retrofit to units with pre-NSPS ESPs, and could become significant with the increasing trend to restricted water discharge.  相似文献   
37.
Sources and concentrations of indoor air pollutants and aeroallergens were evaluated in the arid Southwest community of Tucson, Arizona. One major purpose was to appraise the interaction of indoor and outdoor human exposures. A rough time budget study showed that 74% of adults spent 75% or more of their time in some indoor environment. Outdoor and indoor concentrations of TSP, RSP, CO, O3 and aeroallergens were measured for 41 detached dwellings. Small area and basin monitoring occurred for TSP, CO, NO2, O3 and aeroallergens; ambient TSP frequently exceeds NAAQS and both CO and O3 do occasionally. Indoor TSP and RSP were lower than outdoors and were of a different composition. Outdoor infiltration falls rapidly for particles and pollen, related to distance Indoors. CO was low and O3 was very low indoors. TSP and RSP correlated significantly with tobacco smoking and CO correlated with gas stove usage. Temperature varied minimally indoors and relative humidity indoors was similar to outdoor readings In this climate. It was concluded that better particle characterization and better estimates of total exposure are required.  相似文献   
38.
Extensive research has been conducted globally into conceptual frameworks for ecosystem services, the most notable being the Millennium Ecosystem Assessment (Millennium ecosystem assessment: ecosystems and human well-being; a framework for assessment. World Resources Institute, Washington, DC, pp 51, 53–55, 2005). The South East Queensland (SEQ) Ecosystem Services Framework (Australia) aims to provide the tools to enable government, industry, business, researchers, non-government organizations and land managers to apply the concept of ecosystem services in their planning and management practices. This article describes the Framework and the process that has produced matrices and maps that identify and illustrate the linkages between ecosystems, ecosystem functions, ecosystem services and the community’s well-being. The matrices and maps derived can identify areas in the region where the most ecosystem services are generated. This allows areas to be considered as valuable natural assets of the region, deserving appropriate protection measures or significant offsets if they are diminished or degraded in any way. Although the Framework requires further refinement and ongoing development, the process applied and the products produced has enabled decision makers to turn the concept of ecosystem services into practical application in SEQ.  相似文献   
39.
Sustainable engineering: From myth to mechanism   总被引:1,自引:0,他引:1  
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40.
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