全文获取类型
收费全文 | 753篇 |
免费 | 2篇 |
国内免费 | 5篇 |
专业分类
安全科学 | 24篇 |
废物处理 | 16篇 |
环保管理 | 235篇 |
综合类 | 51篇 |
基础理论 | 139篇 |
污染及防治 | 220篇 |
评价与监测 | 56篇 |
社会与环境 | 15篇 |
灾害及防治 | 4篇 |
出版年
2022年 | 3篇 |
2021年 | 4篇 |
2020年 | 5篇 |
2018年 | 3篇 |
2017年 | 4篇 |
2016年 | 14篇 |
2015年 | 5篇 |
2014年 | 4篇 |
2013年 | 104篇 |
2012年 | 17篇 |
2011年 | 26篇 |
2010年 | 26篇 |
2009年 | 24篇 |
2008年 | 36篇 |
2007年 | 37篇 |
2006年 | 42篇 |
2005年 | 21篇 |
2004年 | 31篇 |
2003年 | 28篇 |
2002年 | 31篇 |
2001年 | 12篇 |
2000年 | 16篇 |
1999年 | 7篇 |
1998年 | 14篇 |
1997年 | 14篇 |
1996年 | 12篇 |
1995年 | 12篇 |
1994年 | 9篇 |
1993年 | 7篇 |
1992年 | 10篇 |
1991年 | 12篇 |
1990年 | 5篇 |
1989年 | 11篇 |
1988年 | 8篇 |
1987年 | 10篇 |
1986年 | 8篇 |
1985年 | 9篇 |
1984年 | 17篇 |
1983年 | 14篇 |
1982年 | 9篇 |
1981年 | 13篇 |
1980年 | 3篇 |
1979年 | 14篇 |
1978年 | 8篇 |
1976年 | 8篇 |
1975年 | 5篇 |
1974年 | 4篇 |
1972年 | 5篇 |
1971年 | 4篇 |
1970年 | 4篇 |
排序方式: 共有760条查询结果,搜索用时 0 毫秒
11.
Gary A. Bishop Brent G. Schuchmann Donald H. Stedman Douglas R. Lawson 《Journal of the Air & Waste Management Association (1995)》2013,63(10):1127-1133
As part of the 2010 Van Nuys tunnel study, researchers from the University of Denver measured on-road fuel-specific light-duty vehicle emissions from nearly 13,000 vehicles on Sherman Way (0.4 miles west of the tunnel) in Van Nuys, California, with its multispecies Fuel Efficiency Automobile Test (FEAT) remote sensor a week ahead of the tunnel measurements. The remote sensing mean gram per kilogram carbon monoxide (CO), hydrocarbon (HC), and oxide of nitrogen (NOx) measurements are 8.9% lower, 41% higher, and 24% higher than the tunnel measurements, respectively. The remote sensing CO/NOx and HC/NOx mass ratios are 28% lower and 20% higher than the comparable tunnel ratios. Comparisons with the historical tunnel measurements show large reductions in CO, HC, and NOx over the past 23 yr, but little change in the HC/NOx mass ratio since 1995. The fleet CO and HC emissions are increasingly dominated by a few gross emitters, with more than a third of the total emissions being contributed by less than 1% of the fleet. An example of this is a 1995 vehicle measured three times with an average HC emission of 419 g/kg fuel (two-stroke snowmobiles average 475 g/kg fuel), responsible for 4% of the total HC emissions. The 2008 economic downturn dramatically reduced the number of new vehicles entering the fleet, leading to an age increase (>1 model year) of the Sherman Way fleet that has increased the fleet's ammonia (NH3) emissions. The mean NH3 levels appear little changed from previous measurements collected in the Van Nuys tunnel in 1993. Comparisons between weekday and weekend data show few fleet differences, although the fraction of light-duty diesel vehicles decreased from the weekday (1.7%) to Saturday (1.2%) and Sunday (0.6%).
Implications: On-road remote sensing emission measurements of light-duty vehicles on Sherman Way in Van Nuys, California, show large historical emission reductions for CO and HC emissions despite an older fleet arising from the 2008 economic downturn. Fleet CO and HC emissions are increasingly dominated by a few gross emitters, with a single 1995 vehicle measured being responsible for 4% of the entire fleet's HC emissions. Finding and repairing and/or scrapping as little as 2% of the fleet would reduce on-road tailpipe emissions by as much as 50%. Ammonia emissions have locally increased with the increasing fleet age. 相似文献
12.
Occurrence of glyphosate and acidic herbicides in select urban rivers and streams in Canada, 2007 总被引:2,自引:1,他引:1
13.
James W. Rivers Philip S. Gipson Donald P. Althoff Jeffrey S. Pontius 《Environmental management》2010,45(2):203-216
Military training activities are known to impact individual species, yet our understanding of how such activities influence
animal communities is limited. In this study, we used long-term data in a case study approach to examine the extent to which
the local small landbird community differed between a site in northeast Kansas that experienced intensive disturbance from
military training activities (Ft. Riley Military Installation) and a similar, nearby site that experienced minimal human disturbance
(Konza Prairie Biological Station). In addition, we characterized how the regional pool of potential colonizers influenced
local community dynamics using Breeding Bird Survey data. From 1991 to 2001, most species of small terrestrial landbirds (73%)
recorded during breeding surveys were found at both sites and the mean annual richness at Ft. Riley (39.0 ± 2.86 [SD]) was
very similar to that of Konza Prairie (39.4 ± 2.01). Richness was maintained at relatively constant levels despite compositional
changes because colonizations compensated local extinctions at both sites. These dynamics were driven primarily by woodland
species that exhibited stochastic losses and gains and were present at a low local and regional abundance. Our results suggest
that military training activities may mimic natural disturbances for some species in this area because the small landbird
community did not differ markedly between sites with and sites without extensive human disturbance. Although our results suggest
that military training is not associated with large changes in the avian community, additional studies are needed to determine
if this pattern is found in other ecological communities. 相似文献
14.
Prasad Pokkunuri Paul Nissenson Donald Dabdub 《Atmospheric environment (Oxford, England : 1994)》2010,44(2):153-163
Three different mass-transfer expressions are employed within the Model of Aerosol, Gas, and Interfacial Chemistry (MAGIC) to study gas-phase molecular chlorine and bromine production from NaCl and NaBr aerosols, respectively. Simulations of chamber experiments are performed in which NaCl aerosols react with gas-phase ozone in the presence of UV light, in order to identify the importance of the Knudsen number and mass-transfer expression in systems with varying contributions from gas-phase, aqueous-phase, and interfacial chemistry. In the case of NaBr aerosols, simulations are performed of both dark and photolytic conditions. A range of Knudsen numbers spanning the continuum, transition and free-molecular regimes is studied. Particle size is varied over three orders of magnitude, and particle concentration is changed to keep either (a) total aerosol volume or (b) total aerosol surface area constant. When total aerosol volume is constant, the total amount of surface area available for interfacial reaction increases linearly with Knudsen number. Consequently peak gas-phase Cl2 and Br2 concentrations increase by two orders of magnitude from the continuum regime to the free-molecular regime. When total aerosol surface area is constant, total aerosol volume is inversely proportional to Knudsen number, with lesser volume being available at higher Knudsen numbers. Consequently Cl? depletion in the kinetic regime leads to most gas-phase Cl2 being produced in the transition regime. Gas-phase Br2 concentration trends are determined by aqueous-phase reaction mechanisms, leading to a monotonic decrease in production with Knudsen number. At all Knudsen numbers, more gas-phase bromine is produced in the photolytic case than in the dark case, the difference being significant in the transition regime. Results of this study suggest that halogen production is insensitive to the mass-transfer expression used in the simulations. 相似文献
15.
16.
17.
Donald G. Gillette 《Journal of the Air & Waste Management Association (1995)》2013,63(4):329-331
The body of information presented in this paper is directed to policy makers and administrators involved in the evaluation and assessment of damages caused by oxidant air pollution on human health and welfare and of possible benefits of control. To provide a comparison of some of the benefits that can be obtained by reducing photochemical oxidant levels, estimated health costs were derived from data relating adverse health effects to hourly oxidant concentrations. Hourly oxidant or ozone concentrations were measured at approximately 400 monitoring stations scattered throughout the U.S. Most of these sites were located in major urban areas or in other areas where high oxidant concentrations prevailed. Estimates of populations at risk and per capita health costs were generated for those areas where oxidant data was available. During the period 1971-1973, nearly two-thirds of the U.S. population resided in areas where the hourly primary standard for oxidants of 160 µg/m3 was exceeded. The total annual health cost attributable to oxidants was estimated to range from $120 to over $240 million in the U.S. 相似文献
18.
Lu Q He ZL Graetz DA Stoffella PJ Yang X 《Environmental science and pollution research international》2011,18(6):978-986
Background, aim and scope
Water quality impairment by heavy metal contamination is on the rise worldwide. Phytoremediation technology has been increasingly applied to remediate wastewater and stormwater polluted by heavy metals. 相似文献19.
Incineration of municipal refuse results in the production of massive quantities of fly ash and bottom ash. Toxic elements in the original refuse may be concentrated up to 40-fold in the resultant ash. There is concern that burial of such ash in landfills could result in leaching of these elements downward into groundwater. In this study, refuse ashes were incorporated into glass, ceramic and cement composites to immobilize such toxic elements. The EP Toxicity Test (1986) was used to show that extraction of such elements by simulated acid rain is effectively blocked in these new solid materials. 相似文献
20.