全文获取类型
收费全文 | 487篇 |
免费 | 7篇 |
国内免费 | 7篇 |
专业分类
安全科学 | 23篇 |
废物处理 | 23篇 |
环保管理 | 133篇 |
综合类 | 48篇 |
基础理论 | 116篇 |
环境理论 | 1篇 |
污染及防治 | 96篇 |
评价与监测 | 42篇 |
社会与环境 | 13篇 |
灾害及防治 | 6篇 |
出版年
2023年 | 3篇 |
2022年 | 2篇 |
2021年 | 5篇 |
2020年 | 3篇 |
2019年 | 5篇 |
2018年 | 9篇 |
2017年 | 8篇 |
2016年 | 14篇 |
2015年 | 13篇 |
2014年 | 11篇 |
2013年 | 47篇 |
2012年 | 16篇 |
2011年 | 28篇 |
2010年 | 17篇 |
2009年 | 18篇 |
2008年 | 27篇 |
2007年 | 28篇 |
2006年 | 15篇 |
2005年 | 14篇 |
2004年 | 9篇 |
2003年 | 23篇 |
2002年 | 15篇 |
2001年 | 6篇 |
2000年 | 2篇 |
1999年 | 5篇 |
1998年 | 15篇 |
1997年 | 10篇 |
1996年 | 7篇 |
1995年 | 7篇 |
1994年 | 2篇 |
1993年 | 4篇 |
1992年 | 5篇 |
1991年 | 7篇 |
1990年 | 5篇 |
1989年 | 6篇 |
1988年 | 7篇 |
1987年 | 5篇 |
1986年 | 3篇 |
1985年 | 4篇 |
1984年 | 9篇 |
1983年 | 8篇 |
1982年 | 6篇 |
1981年 | 6篇 |
1980年 | 6篇 |
1979年 | 5篇 |
1978年 | 5篇 |
1977年 | 5篇 |
1975年 | 3篇 |
1974年 | 4篇 |
1973年 | 8篇 |
排序方式: 共有501条查询结果,搜索用时 31 毫秒
371.
Joanna Endter‐Wada Judith Kurtzman Sean P. Keenan Roger K. Kjelgren Christopher M.U. Neale 《Journal of the American Water Resources Association》2008,44(4):902-920
Abstract: Landscape water conservation is an important issue for municipalities throughout the Western United States, and especially in Utah as rapid growth strains existing water supplies. We conducted interdisciplinary research in Layton, Utah, that aimed at understanding patterns of landscape water use among households and businesses. The research project involved three basic tasks. First, a landscape “water budget” was developed by producing a calibrated and classified mosaic of landscape type and area from airborne multispectral digital imagery, integrating this information with Layton City parcel boundary data to determine landscape vegetated areas per lot, and estimating irrigation needs derived from reference evapotranspiration (ETo) obtained using weather data for the Salt Lake City metropolitan region. Second, utilizing Layton water billing data, water use for each household and business was identified and categorized as “conserving,”“acceptable” or “wasteful” by determining how much the water applied varied from actual landscape plant need. Third, surveys were administered to a random stratified sample of households and businesses in the study area to investigate various factors that were hypothesized to be predictive of wasteful watering practices. This paper primarily focuses on analysis of the household and business survey data, which explores factors affecting urban landscape water use from a human behavioral perspective. We found that the most significant factors predicting actual water use were the type of irrigation system and whether the location was a household or business. Attitudinal and motivational characteristics were not consistently associated with water use. We found that wasteful watering is the result of many factors embedded in the complex context of urban landscapes. This implies that water conservation programs should identify potential wasteful users through analyses of water billing data and direct water conservation measures at these users by focusing on site‐specific evaluations and recommendations. Water audits or water checks are one such tool that some communities have employed to help people understand and assess the quantity of water needed by and applied to their landscapes. This approach provides an opportunity to evaluate situational constraints at particular locations and design appropriate strategies for reducing water waste. 相似文献
372.
We describe the primary aerobic biodegradation of a B20 fuel (20% soybean fatty acid methyl esters, 80% petroleum diesel) by unacclimated inocula from a rainwater detention pond. Biodegradation was rapid and essentially complete, with an overall median 'half-life', at approximately 100 ppm B20, of 6.8 days (n=34). Using purge-and-trap and extraction methodologies, both coupled to GC/MS, and hexachloroethane and hexachlorobenzene as conserved internal markers in the B20, we followed the biodegradation of total detectable material, 76 individual analytes and eight undifferentiated groups of isomers, and calculated their half-lives under these conditions. The fatty acid methyl esters, n-alkanes and iso-alkanes, and simple and alkylated aromatic compounds were the most readily degraded compounds, followed by the naphthenes. The last (identified) compounds to be degraded were ethylalkanes, trisubstituted cyclohexanes and decalins, but even these disappeared with an apparent 'half-life' of <30 days. 相似文献
373.
374.
Burger J Greenberg M Gochfeld M Shukla S Lowrie K Keren R 《Environmental monitoring and assessment》2008,137(1-3):413-425
Considerable research indicates that a wide range of socio-economic factors influence attitudes and perceptions about environmental
hazards and risks, and that social trust in those who manage a hazard is strongly correlated to judgements about risks and
benefits. We suggest that there are three steps that lead to environmental risk perceptions: acquisition of information, interpretation
and synthesis of different pieces of information, and understanding of that information in light of previous knowledge, perceptions,
or attitudes. In this study we presented 211 college students in the sciences and non-sciences with ecological and exposure
information using text, tables and maps to examine the factors that affect information acquisition and interpretation concerning
ecological issues at a fictitious hazardous waste site. Students were allowed about an hour to read the materials and answer
questions. The percent of students answering each question correctly varied from 4 to 82%, indicating that some questions
were extremely difficult to answer. We attributed these differences to variations in the number of places information was
presented (in text, tables, maps, or a combination) and the complexity of the information (how many pieces of information
were required to answer the question correctly). The correlation between the number of students answering each question correctly
and these combined measures (frequency, complexity) was −0.72. Thus, although there were differences in accuracy concerning
ecological information as presented in this study, the major differences were accounted for by how the information was presented,
and how much information was required. This suggests that risk communicators should carefully determine which ecological information
is critical for the target audience, and ensure that it is presented several times (in different forms). That a lower percentage
of people correctly answered questions that required synthesizing several pieces of information suggests that this complexity
should be reduced where possible, or that the pieces of information should be tied clearly to the conclusion. Self-declaration
of effort and perceptions of safety of the site did not markedly influence the relationship between accuracy, difficulty of
finding information, and complexity of information. Other possible confounding variables (i.e., science vs non-science major)
only accounted for about 27% of the variation in student’s overall score on ecological questions; age, ethnicity, and gender
did not enter as significant variables. We cannot manage environmental hazards with appropriate stakeholder input unless we
understand how to present environmental information to achieve a full understanding. Protection of human health and the environment
requires that people understand ecological and exposure information, particularly on buffer lands. 相似文献
375.
376.
Roger C. Prince Josh D. Butler 《Environmental science and pollution research international》2014,21(16):9506-9510
Dispersants are important tools in oil spill response. Taking advantage of the energy in even small waves, they disperse floating oil slicks into tiny droplets (<70 μm) that entrain in the water column and drift apart so that they do not re-agglomerate to re-form a floating slick. The dramatically increased surface area allows microbial access to much more of the oil, and diffusion and dilution lead to oil concentrations where natural background levels of biologically available oxygen, nitrogen, and phosphorus are sufficient for microbial growth and oil consumption. Dispersants are only used on substantial spills in relatively deep water (usually >10 m), conditions that are impossible to replicate in the laboratory. To date, laboratory experiments aimed at following the biodegradation of dispersed oil usually show only minimal stimulation of the rate of biodegradation, but principally because the oil in these experiments disperses fairly effectively without dispersant. What is needed is a test protocol that allows comparison between an untreated slick that remains on the water surface during the entire biodegradation study and dispersant-treated oil that remains in the water column as small dispersed oil droplets. We show here that when this is accomplished, the rate of biodegradation is dramatically stimulated by an effective dispersant, Corexit 9500®. Further development of this approach might result in a useful tool for comparing the full benefits of different dispersants. 相似文献
377.
378.
Karen R. Darnall Roger Atkinson Arthur M. Winer James N. Pitts Jr. 《Journal of the Air & Waste Management Association (1995)》2013,63(3):262-264
Abstract 1-Bromo-propane (1-BP) is a replacement for high-end chlorofluorocarbon (HCFC) solvents. Its reaction rate constant with the OH radical is, on a weight basis, significantly less than that of ethane. However, the overall smog formation chemistry of 1-BP appears to be very unusual compared with typical volatile organic compounds (VOCs) and relatively complex because of the presence of bromine. In smog chamber experiments, 1-BP initially shows a faster ozone build-up than what would be expected from ethane, but the secondary products containing bromine tend to destroy ozone such that 1-BP can have a net overall negative reactivity. Alternative sets of reactions are offered to explain this unusual behavior. Follow-up studies are suggested to resolve the chemistry. Using one set of bromine-related reactions in a photo-chemical grid model shows that 1-BP would be less reactive toward peak ozone formation than ethane with a trend toward even lower ozone impacts in the future. 相似文献
379.
The Evolution of Particles in the Plume from a Large Coal-Fired Boiler with Flue Gas Desulfurization
Robert E. Imhoff Roger L. Tanner Ralph J. Valente Menachem Luria 《Journal of the Air & Waste Management Association (1995)》2013,63(7):1207-1214
ABSTRACT Airborne measurements were made of gaseous and particulate species in the plume of a large coal-fired power plant after flue gas desulfurization (FGD) controls were installed. These measurements were compared with measurements made before the controls were installed. The light scattering and number and volume distributions of plume excess particles were determined by nephelometry and optical particle counting techniques. The plume impact based on optical techniques was much lower than that observed in earlier measurements. Indeed, plume excess volumes as a function of particle size were of the same magnitude as the variability of the background volume distribution. In situ excess plume scattering actually decreased with distance from the source, in contrast to pre-FGD conditions. The upper limit for the dry rate of SO2-to-SO4 2- conversion was estimated from plume excess volume measurements to be about 4% lir1. This is slightly greater than the upper limit, 3.5% lir1, estimated by earlier researchers, but the same as that estimated using the present technique with the earlier data. The cross-plume profile of volume suggests SO2-to-SO4 2- conversion is highest at the plume edges. The greatest benefit of SO2 reduction on plume excess volume and visibility appears to occur far downwind of the source. 相似文献
380.
Menachem Luria Robert E. Imhoff Ralph J. Valente William J. Parkhurst Roger L. Tanner 《Journal of the Air & Waste Management Association (1995)》2013,63(10):1408-1413
ABSTRACT The rate of conversion of SO2 to SO4 2- was re-estimated from measurements made in the plume of the Cumberland power plant, located on the Cumberland River in north-central Tennessee, after installation of flue gas desulfurization (FGD) scrubbers for SO2 removal in 1994. The ratio of SO2 to NOy emissions into the plume has been reduced to ~0.1, compared with a prescrubber value of ~2. To determine whether the SO2 emissions reduction has correspondingly reduced plume-generated particulate SO4 2- production, we have compared the rates of conversion before and after scrubber installation. The prescrubber estimates were developed from measurements made during the Tennessee Plume Study conducted in the late 1970s. The post-scrubber estimates are based upon two series of research flights in the summers of 1998 and 1999. During two of these flights, the Cumberland plume did not mix with adjacent power plant plumes, enabling rate constants for conversion to be estimated from samples taken in the plume at three downwind distances. Dry deposition losses and the fact the fact that SO2 is no longer in large excess compared with SO4 2- have been taken into account, and an upper limit for the conversion rate constant was re-estimated based on plume excess aerosol volume. The estimated upper limit values are 0.069 hr-1 and 0.034 hr-1 for the 1998 and 1999 data, respectively. The 1999 rate is comparable with earlier values for nonscrubbed plumes, and although the 1998 upper limit value is higher than expected, these estimates do not provide strong evidence for deviation from a linear relationship between SO2 emissions and SO4 2- formation. 相似文献