全文获取类型
收费全文 | 1088篇 |
免费 | 31篇 |
国内免费 | 9篇 |
专业分类
安全科学 | 71篇 |
废物处理 | 39篇 |
环保管理 | 294篇 |
综合类 | 83篇 |
基础理论 | 311篇 |
环境理论 | 3篇 |
污染及防治 | 192篇 |
评价与监测 | 84篇 |
社会与环境 | 46篇 |
灾害及防治 | 5篇 |
出版年
2023年 | 10篇 |
2022年 | 13篇 |
2021年 | 15篇 |
2020年 | 16篇 |
2019年 | 14篇 |
2018年 | 25篇 |
2017年 | 32篇 |
2016年 | 43篇 |
2015年 | 28篇 |
2014年 | 33篇 |
2013年 | 73篇 |
2012年 | 52篇 |
2011年 | 74篇 |
2010年 | 49篇 |
2009年 | 42篇 |
2008年 | 61篇 |
2007年 | 67篇 |
2006年 | 60篇 |
2005年 | 41篇 |
2004年 | 44篇 |
2003年 | 47篇 |
2002年 | 35篇 |
2001年 | 21篇 |
2000年 | 12篇 |
1999年 | 21篇 |
1998年 | 17篇 |
1997年 | 15篇 |
1996年 | 22篇 |
1995年 | 22篇 |
1994年 | 15篇 |
1993年 | 13篇 |
1992年 | 10篇 |
1991年 | 9篇 |
1990年 | 7篇 |
1989年 | 7篇 |
1988年 | 8篇 |
1987年 | 6篇 |
1986年 | 2篇 |
1985年 | 4篇 |
1984年 | 9篇 |
1983年 | 5篇 |
1982年 | 6篇 |
1981年 | 4篇 |
1979年 | 3篇 |
1978年 | 5篇 |
1977年 | 2篇 |
1974年 | 2篇 |
1972年 | 2篇 |
1968年 | 1篇 |
1938年 | 1篇 |
排序方式: 共有1128条查询结果,搜索用时 62 毫秒
31.
PROBLEM: Safety-belt use reduces motor vehicle crash-related morbidity and mortality, yet an estimated 18% of drivers do not consistently buckle up (NHTSA, 2005). In 1985, Geller and colleagues developed an interpersonal Flash-for-Life prompt that increased belt use among 22% of 1,087 unbuckled drivers (Geller, Bruff, & Nimmer, 1985). METHOD: The Flash-for-Life intervention was re-introduced at a large university with high safety-belt use (i.e., 80%). College students stood at parking-lot entrance/exits and "flashed" signs with the message, "Please Buckle Up, I Care" to unbuckled drivers. RESULTS: Of 427 unbuckled drivers observed, 30% of these complied with the prompt. Male drivers were significantly more likely to comply with prompts delivered by females. DISCUSSION: Compliance was higher than in the 1985 study, indicating a high baseline rate of safety-belt use does not negate potential beneficial influence of a prompting intervention. This intervention is particularly effective with college-aged males, a sub-group of the driving population least likely to buckle-up. IMPACT ON INDUSTRY: A simple behavioral prompt could be used at most industrial complexes to increase safety-belt use among vehicle occupants who are not buckled-up. 相似文献
32.
33.
Leclaire S Merkling T Raynaud C Giacinti G Bessière JM Hatch SA Danchin E 《Die Naturwissenschaften》2011,98(7):615-624
The importance of olfaction in birds’ social behavior has long been denied. Avian chemical signaling has thus been relatively
unexplored. The black-legged kittiwake provides a particularly appropriate model for investigating this topic. Kittiwakes
preferentially mate with genetically dissimilar individuals, but the cues used to assess genetic characteristics remain unknown.
As in other vertebrates, their body odors may carry individual and sexual signatures thus potentially reliably signaling individual
genetic makeup. Here, we test whether body odors in preen gland secretion and preen down feathers in kittiwakes may provide
a sex and an individual signature. Using gas chromatography and mass spectrometry, we found that male and female odors differ
quantitatively, suggesting that scent may be one of the multiple cues used by birds to discriminate between sexes. We further
detected an individual signature in the volatile and nonvolatile fractions of preen secretion and preen down feathers. These
results suggest that kittiwake body odor may function as a signal associated with mate recognition. It further suggests that
preen odor might broadcast the genetic makeup of individuals, and could be used in mate choice to assess the genetic compatibility
of potential mates. 相似文献
34.
The off-gas handling system is a vital component of a smelter and it is essential that it operates in accordance with environmental regulations. A key feature of the off-gas management system is maintaining a slightly negative system pressure to prevent gas leakage, such as SO2, out into the work and external environments. To enhance sustainable development, there is also growing interest in capturing and reusing the significant amount of heat and CO2 contained within off-gas. The potential incorporation of heat and CO2 recovery systems places importance on enhancing control to minimize the risk of both gas leakage and disturbance of the smelting process. With these requirements in mind, an easily implementable feedforward control enhancement to existing control schemes is proposed to help provide improved performance. 相似文献
35.
The extensive literature on environmental justice has, by now, well defined the essential ingredients of cumulative risk,
namely, incompatible land uses and vulnerability. Most problematic is the case when risk is produced by a large aggregation
of small sources of air toxics. In this article, we test these notions in an area of Southern California, Southeast Los Angeles
(SELA), which has come to be known as Asthmatown. Developing a rapid risk mapping protocol, we scan the neighborhood for small
potential sources of air toxics and find, literally, hundreds of small point sources within a 2-mile radius, interspersed
with residences. We also map the estimated cancer risks and noncancer hazard indices across the landscape. We find that, indeed,
such large aggregations of even small, nondominant sources of air toxics can produce markedly elevated levels of risk. In
this study, the risk profiles show additional cancer risks of up to 800 in a million and noncancer hazard indices of up to
200 in SELA due to the agglomeration of small point sources. This is significant (for example, estimates of the average regional
point-source-related cancer risk range from 125 to 200 in a million). Most importantly, if we were to talk about the risk
contour as if they were geological structures, we would observe not only a handful of distinct peaks, but a general “mountain
range” running all throughout the study area, which underscores the ubiquity of risk in SELA. Just as cumulative risk has
deeply embedded itself into the fabric of the place, so, too, must intervention seek to embed strategies into the institutions
and practices of SELA. This has implications for advocacy, as seen in a recently initiated participatory action research project
aimed at building health research capacities into the community in keeping with an ethic of care. 相似文献
36.
37.
Coupling of the Water Cycle with Patterns of Urban Growth in the Baltimore Metropolitan Region,United States 下载免费PDF全文
Aditi S. Bhaskar Claire Jantz Claire Welty Scott A. Drzyzga Andrew J. Miller 《Journal of the American Water Resources Association》2016,52(6):1509-1523
Regional municipal water plans typically do not recognize complex coupling patterns or that increased withdrawals in one location can result in changes in water availability in others. We investigated the interaction between urban growth and water availability in the Baltimore metropolitan region where urban growth has occurred beyond the reaches of municipal water systems into areas that rely on wells in low‐productivity Piedmont aquifers. We used the urban growth model SLEUTH and the hydrologic model ParFlow.CLM to evaluate this interaction with urban growth scenarios in 2007 and 2030. We found decreasing groundwater availability outside of the municipal water service area. Within the municipal service area we found zones of increasing storage resulting from increased urban growth, where reduced vegetation cover dominated the effect of urbanization on the hydrologic cycle. We also found areas of decreasing storage, where expanding impervious surfaces played a larger role. Although the magnitude of urban growth and change in water availability for the simulation period were generally small, there was considerable spatial heterogeneity of changes in subsurface storage. This suggests that there are locally concentrated areas of groundwater sensitivity to urban growth where water shortages could occur or where drying up of headwater streams would be more likely. The simulation approach presented here could be used to identify early warning indicators of future risk. 相似文献
38.
Climate change generally requires species to migrate northward or to higher elevation to maintain constant climate conditions, but migration requirement and migration capacity of individual species can vary greatly. Individual populations of species occupy different positions in the landscape that determine their required range shift to maintain similar climate, and likewise the migration capacity depends on habitat connectivity. Here, we demonstrate an approach to quantifying species vulnerabilities to climate change for 419 rare vascular plants in Alberta, Canada, based on a multivariate velocity of climate change metric, local habitat fragmentation, and migration capacity. Climate change velocities indicated that future migration requirements ranged from 1 to 5 km/year in topographically complex landscapes, such as the Alberta Foothills and Rocky Mountains. In contrast, migration requirements to maintain constant climate in relatively flat Boreal Plains, Parkland, and Grassland ranged from 4 to 8 km/year. Habitat fragmentation was also highest in these flat regions, particularly the Parkland Natural Region. Of the 419 rare vascular plants assessed, 36 were globally threatened (G1–G3 ranking). Three globally threatened species were ranked as extremely vulnerable and five species as highly vulnerable to the interactions among climate change velocity, habitat fragmentation, and migration capacity. Incorporating dispersal characteristics and habitat fragmentation with local patterns in climate change velocity improves the assessment of climate change threats to species and may be applied to guide monitoring efforts or conservation actions. 相似文献
39.
Cora J. Young Michael D. Hurley Timothy J. Wallington Scott A. Mabury 《Atmospheric environment (Oxford, England : 1994)》2009,43(24):3717-3724
Relative rate techniques were used to determine k(Cl + CF3CFCFCF3) = (7.27 ± 0.88) × 10?12, k(Cl + CF3CF2CFCF2) = (1.79 ± 0.41) × 10?11, k(OH + CF3CFCFCF3) = (4.82 ± 1.15) × 10?13, and k(OH + CF3CF2CFCF2) = (1.94 ± 0.27) × 10?12 cm3 molecule?1 s?1 in 700 Torr of air or N2 diluent at 296 K. The chlorine atom- and OH radical-initiated oxidation of CF3CFCFCF3 in 700 Torr of air gives CF3C(O)F in molar yields of 196 ± 11 and 218 ± 20%, respectively. Chlorine atom-initiated oxidation of CF3CF2CFCF2 gives molar yields of 97 ± 9% CF3CF2C(O)F and 97 ± 9% COF2. OH radical-initiated oxidation of CF3CF2CFCF2 gives molar yields of 110 ± 15% CF3CF2C(O)F and 99 ± 8% COF2. The atmospheric fate of CF3CF2C(O)F and CF3C(O)F is hydrolysis to give CF3CF2C(O)OH and CF3C(O)OH. The atmospheric lifetimes of CF3CFCFCF3 and CF3CF2CFCF2 are determined by reaction with OH radicals and are approximately 24 and 6 days, respectively. The contribution of CF3CFCFCF3 and CF3CF2CFCF2 to radiative forcing of climate change will be negligible. 相似文献
40.
Yung-Ping Tseng Gerard T. Kyle C. Scott Shafer Alan R. Graefe Timothy A. Bradle Michael A. Schuett 《Environmental management》2009,43(3):496-507
Along with the growing boating population and the number of boats in use on limited inland waterways, boater expectations
of setting density, safety perceptions, and the associated impacts on their experience (e.g., satisfaction) are becoming increasingly
important. The primary purpose of this article was to explore a recreational boating crowding–satisfaction model derived from
previous work using safety and enjoyment as mediating variables. We also tested our crowding–satisfaction model among day
and overnight users. Our analysis revealed no significant difference between day and overnight users for any of the relationships
tested in our model. Our final model indicated as respondents’ expectations for seeing people increased along with their feelings
of being crowded, they were more inclined to consider the conditions on the lake as being unsafe. They were also more inclined
to indicate that the number of people they had seen on the lake detracted from their boating experience. Respondents’ satisfaction
was tied to their perceptions of crowding. Mediating variables illustrated that the relationship was conditioned by perceptions
of safety and enjoyment. Analysis of the indirect effect observed in our study illustrate that when the number of people seen
on the lake exceed respondents’ expectations, their perceptions of safety and enjoyment both decline, resulting in lower satisfaction.
These findings have implications for managing recreational boating use on inland lake systems. Given the role played by expectations
in our model, efforts to communicate with boaters about conditions on these waterways is important for helping them plan their
boating experience and avoid situations they consider unsafe or unsatisfactory. 相似文献