全文获取类型
收费全文 | 915篇 |
免费 | 8篇 |
国内免费 | 15篇 |
专业分类
安全科学 | 27篇 |
废物处理 | 53篇 |
环保管理 | 93篇 |
综合类 | 142篇 |
基础理论 | 204篇 |
环境理论 | 2篇 |
污染及防治 | 302篇 |
评价与监测 | 55篇 |
社会与环境 | 58篇 |
灾害及防治 | 2篇 |
出版年
2023年 | 2篇 |
2022年 | 15篇 |
2021年 | 17篇 |
2020年 | 8篇 |
2019年 | 8篇 |
2018年 | 29篇 |
2017年 | 36篇 |
2016年 | 36篇 |
2015年 | 31篇 |
2014年 | 29篇 |
2013年 | 93篇 |
2012年 | 47篇 |
2011年 | 73篇 |
2010年 | 56篇 |
2009年 | 55篇 |
2008年 | 66篇 |
2007年 | 53篇 |
2006年 | 47篇 |
2005年 | 31篇 |
2004年 | 29篇 |
2003年 | 31篇 |
2002年 | 19篇 |
2001年 | 8篇 |
2000年 | 6篇 |
1999年 | 6篇 |
1998年 | 8篇 |
1997年 | 9篇 |
1996年 | 4篇 |
1995年 | 12篇 |
1994年 | 2篇 |
1993年 | 4篇 |
1991年 | 4篇 |
1990年 | 3篇 |
1987年 | 2篇 |
1981年 | 3篇 |
1965年 | 7篇 |
1964年 | 3篇 |
1963年 | 4篇 |
1962年 | 9篇 |
1961年 | 11篇 |
1960年 | 1篇 |
1958年 | 2篇 |
1957年 | 1篇 |
1956年 | 1篇 |
1954年 | 1篇 |
1947年 | 1篇 |
1942年 | 1篇 |
1941年 | 2篇 |
1938年 | 1篇 |
1932年 | 1篇 |
排序方式: 共有938条查询结果,搜索用时 218 毫秒
811.
Stream Condition in Piedmont Streams with Restored Riparian Buffers in the Chesapeake Bay Watershed1
Leslie L. Orzetti R. Christian Jones Robert F. Murphy 《Journal of the American Water Resources Association》2010,46(3):473-485
Orzetti, Leslie L., R. Christian Jones, and Robert F. Murphy, 2010. Stream Condition in Piedmont Streams with Restored Riparian Buffers in the Chesapeake Bay Watershed. Journal of the American Water Resources Association (JAWRA) 46(3):473-485. DOI: 10.1111/j.1752-1688.2009.00414.x Abstract: This study tested the efficacy of restored forest riparian buffers along streams in the Chesapeake Bay watershed by examining habitat, selected water quality variables, and benthic macroinvertebrate community metrics in 30 streams with buffers ranging from zero to greater than 50 years of age. To assess water quality we measured in situ parameters (temperature, dissolved oxygen, and conductivity) and laboratory-analyzed grab samples (soluble reactive phosphorus, total phosphorus, nitrate, ammonium, and total suspended solids). Habitat conditions were scored using the Environmental Protection Agency Rapid Bioassessment Protocols for high gradient streams. Benthic macroinvertebrates were quantified using pooled riffle/run kick samples. Results showed that habitat, water quality, and benthic macroinvertebrate metrics generally improved with age of restored buffer. Habitat scores appeared to stabilize between 10 and 15 years of age and were driven mostly by epifaunal substrate availability, sinuosity, embeddedness, and velocity depth regime. Benthic invertebrate taxa richness, percent Ephemeroptera, Plecoptera, Trichoptera minus hydropsychids (%EPT minus H), % Ephemeroptera, and the Family Biotic Index were among the metrics which improved with age of buffer zone. Results are consistent with the hypothesis that forest riparian buffers enhance instream habitat, water quality, and resulting benthic macroinvertebrate communities with noticeable improvements occurring within 5-10 years postrestoration, leading to conditions approaching those of long established buffers within 10-15 years of restoration. 相似文献
812.
Bryan N. Duncan Yasuko Yoshida Jennifer R. Olson Sanford Sillman Randall V. Martin Lok Lamsal Yongtao Hu Kenneth E. Pickering Christian Retscher Dale J. Allen James H. Crawford 《Atmospheric environment (Oxford, England : 1994)》2010,44(18):2213-2223
We investigated variations in the relative sensitivity of surface ozone formation in summer to precursor species concentrations of volatile organic compounds (VOCs) and nitrogen oxides (NOx) as inferred from the ratio of the tropospheric columns of formaldehyde to nitrogen dioxide (the “Ratio”) from the Aura Ozone Monitoring Instrument (OMI). Our modeling study suggests that ozone formation decreases with reductions in VOCs at Ratios <1 and NOx at Ratios >2; both NOx and VOC reductions may decrease ozone formation for Ratios between 1 and 2. Using this criteria, the OMI data indicate that ozone formation became: 1. more sensitive to NOx over most of the United States from 2005 to 2007 because of the substantial decrease in NOx emissions, primarily from stationary sources, and the concomitant decrease in the tropospheric column of NO2, and 2. more sensitive to NOx with increasing temperature, in part because emissions of highly reactive, biogenic isoprene increase with temperature, thus increasing the total VOC reactivity. In cities with relatively low isoprene emissions (e.g., Chicago), the data clearly indicate that ozone formation became more sensitive to NOx from 2005 to 2007. In cities with relatively high isoprene emissions (e.g., Atlanta), we found that the increase in the Ratio due to decreasing NOx emissions was not obvious as this signal was convolved with variations in the Ratio associated with the temperature dependence of isoprene emissions and, consequently, the formaldehyde concentration. 相似文献
813.
Erika von Schneidemesser Paul S. Monks Christian Plass-Duelmer 《Atmospheric environment (Oxford, England : 1994)》2010,44(39):5053-5064
Speciated volatile organic compound (VOC) and carbon monoxide (CO) measurements from the Marylebone Road site in central London from 1998 through 2008 are presented. Long-term trends show statistically significant decreases for all the VOCs considered, ranging from ?3% to ?26% per year. Carbon monoxide decreased by ?12% per year over the measurement period. The VOC trends observed at the kerbside site in London showed greater rates of decline relative to trends from monitoring sites in rural England (Harwell) and a remote high-altitude site (Hohenpeissenberg), which showed decreases for individual VOCs from ?2% to ?13% per year. Over the same 1998 through 2008 period VOC to CO ratios for London remained steady, an indication that emissions reduction measures affected the measured compounds equally. Relative trends comparing VOC to CO ratios between Marylebone Road and Hohenpeissenberg showed greater similarities than absolute trends, indicating that emissions reductions measures in urban areas are reflected by regional background locations. A comparison of VOC mixing ratios and VOC to CO ratios was undertaken for London and other global cities. Carbon monoxide and VOCs (alkanes greater than C5, alkenes, and aromatics) were found to be strongly correlated (>0.8) in the Annex I countries, whereas only ethene and ethyne were strongly correlated with CO in the non-Annex I countries. The correlation results indicate significant emissions from traffic-related sources in Annex I countries, and a much larger influence of other sources, such as industry and LPG-related sources in non-Annex I countries. Yearly benzene to ethyne ratios for London from 2000 to 2008 ranged from 0.17 to 0.29 and compared well with previous results from US cities and three global megacities. 相似文献
814.
Kati Berninger Wiktor Adamowicz Daniel Kneeshaw Christian Messier 《Environmental management》2010,46(1):117-133
The challenge of sustainable forest management is to integrate diverse and sometimes conflicting management objectives. In
order to achieve this goal, we need a better understanding of the aspects influencing the preferences of diverse groups and
how these groups make trade-offs between different attributes of SFM. We compare the SFM preferences of interest groups in
regions with different forest use histories based on the reasoning that the condition of the forest reflects the forest use
history of the area. The condition of the forest also shapes an individual’s forest values and attitudes. These held values
and attitudes are thought to influence SFM preferences. We tested whether the SFM preferences vary amongst the different interest
groups within and across regions. We collected data from 252 persons using a choice experiment approach, where participants
chose multiple times among different options described by a combination of attributes that are assigned different levels.
The novelty of our approach was the use of choice experiments in the assessment of regional preference differences. Given
the complexity of inter-regional comparison and the small sample size, this was an exploratory study based on a purposive
rather than random sample. Nevertheless, our results suggest that the aggregation of preferences of all individuals within
a region does not reveal all information necessary for forest management planning since opposing viewpoints could cancel each
other out and lead to an interpretation that does not reflect possibly polarised views. Although based on a small sample size,
the preferences of interest groups within a region are generally statistically significantly different from each other; however
preferences of interest groups across regions are also significantly different. This illustrates the potential importance
of assessing heterogeneity by region and by group. 相似文献
815.
Christian P. Andersen Wilma Ritter Rainer Matyssek 《Environmental pollution (Barking, Essex : 1987)》2010,158(8):2604-2609
Canopies of adult European beech (Fagus sylvatica) and Norway spruce (Picea abies) were labeled with CO2 depleted in 13C to evaluate carbon allocation belowground. One-half the trees were exposed to elevated O3 for 6 yrs prior to and during the experiment. Soil-gas sampling wells were placed at 8 and 15 cm and soil CO2 was sampled during labeling in mid-late August, 2006. In beech, δ13CO2 at both depths decreased approximately 50 h after labeling, reflecting rapid translocation of fixed C to roots and release through respiration. In spruce, label was detected in fine-root tissue, but there was no evidence of label in δ13CO2. The results show that C fixed in the canopy rapidly reaches respiratory pools in beech roots, and suggest that spruce may allocate very little of recently-fixed carbon into root respiration during late summer. A change in carbon allocation belowground due to long-term O3 exposure was not observed. 相似文献
816.
Rakkestad KE Dye CJ Yttri KE Holme JA Hongslo JK Schwarze PE Becher R 《Journal of environmental monitoring : JEM》2007,9(12):1419-1425
Phthalates are found in numerous consumer products, including interior materials like polyvinyl chloride (PVC). Several studies have identified phthalates in indoor air. A recent case-control study demonstrated associations between allergic symptoms in children and the concentration of phthalates in dust collected from their homes. Here we have analyzed the content of selected phthalates in particulate matter (PM): PM(10) and PM(2.5) filter samples collected in 14 different indoor environments. The results showed the presence of the phthalates di-n-butyl phthalate (DBP), butyl benzyl phthalate (BBP), dicyclohexyl phthalate (DCHP) and diethyl hexyl phthalate (DEHP) in the samples. The dominating phthalate in both PM(10) and PM(2.5) samples from all locations was DBP. More than a 10-fold variation in the mean concentration of total phthalates between sampling sites was observed. The highest levels of total phthalates were detected in one children's room, one kindergarten, in two primary schools, and in a computer room. The relative contribution of total phthalates in PM(10) and PM(2.5) was 1.1 +/- 0.3% for both size fractions. The contribution of total phthalates in PM(2.5) to total phthalates in PM(10) ranged from 23-81%, suggesting different sources. Of the phthalates that were analyzed in the PM material, DBP was found to be the major phthalate in rubber from car tyres. However, our analyses indicate that tyre wear was of minor importance for indoor levels of both DBP as well as total phthalates. Overall, these results support the notion that inhalation of indoor PM contributes to the total phthalate exposure. 相似文献
817.
A new approach for the removal of the pesticide lindane (gamma-hexachlorocyclohexane or gamma-HCH) makes use of catalytic reduction of HCH to benzene over a metal catalyst, namely Pd(0). Since specific surface area plays an important role in reactivity of catalysts, this study investigated the use of bioPd(0), i.e. nano-scale Pd(0) particles precipitated on the biomass of Shewanella oneidensis, for the removal of lindane. It was demonstrated that bioPd(0) has catalytic activity towards dechlorination of gamma-HCH, with the addition of formate as electron donor, and that dechlorination with bioPd(0) was more efficient than with commercial powdered Pd(0). The biodegradable compound benzene was formed as reaction product and other HCH isomers could also be dechlorinated. Subsequently bioPd(0) was implemented in a membrane reactor technology for the treatment of gamma-HCH polluted water. In a fed-batch process configuration with formate as electron donor, a removal percentage of 98% of gamma-HCH saturated water (10 mg l(-1)) was achieved within 24h. The measured chloride mass balance approached the theoretical value. The results of this work showed that a complete, efficient and fast removal of lindane was achieved by biocatalysis with bioPd(0). 相似文献
818.
Evaluation of the critical factors controlling stability of chromium, copper, arsenic and zinc in iron-treated soil 总被引:3,自引:0,他引:3
Various environmental factors are expected to affect the mobility of elements in chemically stabilized soils. The aim of this study was to evaluate the effects of pH, oxidizing-reducing potential (Eh), liquid-to-solid ratio (L/S), presence of organic matter (OM) and microbial activity (MA) on the mobility of chromium, copper, arsenic and zinc in zerovalent iron (Fe(0))-stabilized soil. A 2(5) full factorial design was applied to assess the leaching of the elements from the treated soil. The factor having the most impact on the mobility of Cr, Cu and Zn was pH; low pH (3) led to the release of these elements. Arsenic remobilization was controlled by L/S and MA, whilst Eh, though also significant, had less influence. In the identified worst-case scenarios, more than half of the total Zn and Cu and 14% of As can be expected to remobilize from the treated soil. The leaching procedure concerning sample agitation and type of filtration showed to substantially affect the results of As leaching, especially in OM rich soil. 相似文献
819.
Segura PA García-Ac A Lajeunesse A Ghosh D Gagnon C Sauvé S 《Journal of environmental monitoring : JEM》2007,9(4):307-313
A rugged and specific method based on tandem solid-phase extraction and liquid chromatography-tandem mass spectrometry for the determination of anti-infectives in raw sewage and wastewater plant effluents was developed. Analyte recoveries from spiked effluents ranged from 68 to 104%. Two specific selected reaction monitoring transitions and their peak area ratios were used to avoid false positives and confirm the presence of the targeted substances. Detection limits allowed low nanogram per litre detection (0.3-22 ng L(-1)). The method was successfully applied to real samples from the Montréal wastewater treatment plant. All the studied anti-infectives were found in the wastewater samples in concentrations ranging from 39 to 276 ng L(-1). Mean flows of anti-infectives were estimated from effluent concentrations and it was found that large amounts (>118 g day(-1) up to 830 g day(-1)) are discharged in the receiving waters of the St Lawrence River. 相似文献
820.