全文获取类型
收费全文 | 648篇 |
免费 | 16篇 |
国内免费 | 11篇 |
专业分类
安全科学 | 34篇 |
废物处理 | 16篇 |
环保管理 | 152篇 |
综合类 | 103篇 |
基础理论 | 185篇 |
环境理论 | 1篇 |
污染及防治 | 111篇 |
评价与监测 | 30篇 |
社会与环境 | 27篇 |
灾害及防治 | 16篇 |
出版年
2023年 | 10篇 |
2022年 | 10篇 |
2021年 | 25篇 |
2020年 | 13篇 |
2019年 | 28篇 |
2018年 | 20篇 |
2017年 | 30篇 |
2016年 | 31篇 |
2015年 | 20篇 |
2014年 | 19篇 |
2013年 | 50篇 |
2012年 | 35篇 |
2011年 | 35篇 |
2010年 | 31篇 |
2009年 | 28篇 |
2008年 | 38篇 |
2007年 | 27篇 |
2006年 | 31篇 |
2005年 | 23篇 |
2004年 | 24篇 |
2003年 | 18篇 |
2002年 | 26篇 |
2001年 | 16篇 |
2000年 | 8篇 |
1999年 | 8篇 |
1998年 | 3篇 |
1997年 | 4篇 |
1996年 | 5篇 |
1995年 | 6篇 |
1994年 | 4篇 |
1993年 | 5篇 |
1992年 | 2篇 |
1991年 | 4篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 5篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1983年 | 5篇 |
1982年 | 6篇 |
1981年 | 5篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有675条查询结果,搜索用时 546 毫秒
261.
Christopher E. Hill S. Elizabeth Campbell J. Cully Nordby John M. Burt Michael D. Beecher 《Behavioral ecology and sociobiology》1999,46(5):341-349
Sharing song types with immediate neighbors is widespread in birds with song repertoires, and sharing songs may confer a
selective advantage in some cases. Levels of song sharing vary between different geographical populations of several bird
species, and ecological differences often correlate with differences in singing behavior; in particular, males in migratory
subspecies often share fewer songs than males in resident subspecies. The song sparrow (Melospiza melodia) appears to fit this pattern: resident song sparrows in western North America generally share 20–40% of their repertoire
(of about eight songs) with each neighbor, while migratory subspecies from eastern North America often share 10% or less.
We compared song sharing in two populations within a single subspecies of song sparrow (M. m. morphna) in Washington State. These populations, separated by only 120 km, nonetheless differ in migratory tendencies and several
other ecological and life history variables. We recorded complete song repertoires from 11 male song sparrows in a high-elevation,
migrating population at Gold Creek in west-central Washington, and compared them to two samples (n = 15 and n = 36) from a coastal, resident population at Discovery Park, Seattle, Washington. Despite major differences in habitat, population
density, and migratory tendencies, song sharing among Gold Creek males was as high as that among Discovery Park males. In
both populations, sharing was highest between immediate neighbors, and declined with distance. We conclude that at the within-subspecies
level, neither migration nor population density affect song sharing in song sparrows, a song repertoire species.
Received: 26 November 1998 / Received in revised form: 1 May 1999 / Accepted: 29 May 1999 相似文献
262.
Non-structural streambank stabilization, or bioengineering, is a common stream restoration practice used to slow streambank
erosion, but its ecological effects have rarely been assessed. We surveyed bank habitat and sampled bank macroinvertebrates
at four bioengineered sites, an unrestored site, and a comparatively less-impacted reference site in the urban Peachtree-Nancy
Creek catchment in Atlanta, GA, USA. The amount of organic bank habitat (wood and roots) was much higher at the reference
site and three of the bioengineered sites than at the unrestored site or the other bioengineered site, where a very different
bioengineering technique was used (“joint planting”). At all sites, we saw a high abundance of pollution-tolerant taxa, especially
chironomids and oligochaetes, and a low richness and diversity of the bank macroinvertebrate community. Total biomass, insect
biomass, and non-chironomid insect biomass were highest at the reference site and two of the bioengineered sites (p < 0.05). Higher biomass and abundance were found on organic habitats (wood and roots) versus inorganic habitats (mud, sand,
and rock) across all sites. Percent organic bank habitat at each site proved to be strongly positively correlated with many
factors, including taxon richness, total biomass, and shredder biomass. These results suggest that bioengineered bank stabilization
can have positive effects on bank habitat and macroinvertebrate communities in urban streams, but it cannot completely mitigate
the impacts of urbanization. 相似文献
263.
Lindblom SD Abdel-Ghany S Hanson BR Hwang S Terry N Pilon-Smits EA 《Journal of environmental quality》2006,35(3):726-733
The Stylosanthes hamata SHST1 gene encodes a high-affinity sulfate transporter located in the plasma membrane. In this study the S. hamata SHST1 gene was constitutively expressed in Indian mustard [Brassica juncea (L.) Czern.] to investigate its importance for tolerance and accumulation of various oxyanions that may be transported by SHST1 and for cadmium, which is detoxified by sulfur-rich compounds. The transgenic SHST1 lines SHST1-12C and SHST1-4C were compared with wild-type Indian mustard for tolerance and accumulation of arsenate, chromate, tungstate, vanadate, and cadmium. As seedlings the SHST1 plants accumulated significantly more Cd and W, and somewhat more Cr and V. The SHST1 seedlings were less tolerant to Cd, Mo, and V compared to wild-type plants. Mature SHST1 plants were less tolerant than wild-type plants to Cd and Cr. SHST1 plants accumulated significantly more Cd, Cr, and W in their roots than wild-type plants. In their shoots they accumulated significantly more Cr and somewhat more V and W. Shoot Cd accumulation was significantly lower than in wild-type, and As levels were somewhat reduced. Compared to wild-type plants, sulfur accumulation was enhanced in roots of SHST1 plants but not in shoots. Together these results suggest that SHST1 can facilitate uptake of other oxyanions in addition to sulfate and that SHST1 mediates uptake in roots rather than root-to-shoot translocation. Since SHST1 overexpression led to enhanced accumulation of Cr, Cd, V, and W, this approach shows some potential for phytoremediation, especially if it could be combined with the expression of a gene that confers enhanced metal translocation or tolerance. 相似文献
264.
Meng Zhu Yongming Luo Ruyi Yang Shoubiao Zhou Juqin Zhang Mengyun Zhang Peter Christie Elizabeth L. Rylott 《Frontiers of Environmental Science & Engineering》2020,14(4):58
265.
Magnoli Karen Carranza Cecilia Soledad Aluffi Melisa Eglé Magnoli Carina Elizabeth Barberis Carla Lorena 《Environmental science and pollution research international》2020,27(31):38501-38512
Environmental Science and Pollution Research - One of the main herbicides used in the agricultural environments is 2,4-dichlorophenoxyacetic acid (2,4-D). It is a synthetic plant hormone auxin... 相似文献
266.
The purpose of this study was to explore the ability of place attachment to predict place-specific and general pro-environment behavioural intentions. The study sample (n = 355) consisted of visitors to a Canadian national park, Point Pelee National Park. The place attachment scale utilized in this study was designed to measure three subdimensions: place identity, place dependence, and place affect. Exploratory factor analysis of data measured by these scales revealed two place attachment subdimensions. Place affect, an individual’s emotions and feelings for a place, acted as a more generalized or pervasive phenomenon. Place affect items loaded on both the place identity (an individual’s cognitive assessment of a place) and place dependence (an individual’s functional assessment of a place). Structural equation modeling confirmed the strength of place attachment’s ability to predict place-related pro-environment intentions. It also identified place attachment’s prediction of pro-environment behavioural intensions related to everyday life. Place identity mediated the effects of place dependence in predicting pro-environment intentions. Further research which utilizes in-depth and longitudinal case studies is suggested to explore the role of place-specific emotion and feelings, as well as place identity in fostering environmentally-responsible action as these factors are theorized to play an important role in promoting pro-environmental behaviour. Studies of place attachment to everyday settings rather than iconic national parks are also called for. 相似文献
267.
Elizabeth A. Stone Curtis J. Hedman Jiabin Zhou Mark Mieritz James J. Schauer 《Atmospheric environment (Oxford, England : 1994)》2010,44(3):312-319
This study targets understanding the secondary sources of organic aerosol in Mexico City during the Megacities Impact on Regional and Global Environment (MIRAGE) 2006 field campaign. Ambient PM2.5 was collected daily at urban and peripheral locations. Particle-phase secondary organic aerosol (SOA) products of anthropogenic and biogenic precursor gases were measured by gas chromatography mass spectrometry. Ambient concentrations of SOA tracers were used to estimate organic carbon (OC) from secondary origins (SOC). Anthropogenic SOC was estimated as 20–25% of ambient OC at both sites, while biogenic SOC was less abundant, but was relatively twice as important at the peripheral site. The OC that was not attributed secondary sources or to primary sources in a previous study showed temporal consistency with biomass-burning events, suggesting the importance of secondary processing of biomass-burning emissions in the region. The best estimate of biomass-burning-related SOC was in the range of 20–30% of ambient OC during peak biomass burning events. Low-molecular weight (MW) alkanoic and alkenoic dicarboxylic acids (C2–C5) were also measured, of which oxalic acid was the most abundant. The spatial and temporal trends of oxalic acid differed from tracers for primary and secondary sources, suggesting that it had different and/or multiple sources in the atmosphere. 相似文献
268.
Mae A. Davenport Christopher A. Bridges Jean C. Mangun Andrew D. Carver Karl W. J. Williard Elizabeth O. Jones 《Environmental management》2010,45(4):711-722
Natural resource professionals are increasingly faced with the challenges of cultivating community-based support for wetland
ecosystem restoration. While extensive research efforts have been directed toward understanding the biophysical dimensions
of wetland conservation, the literature provides less guidance on how to successfully integrate community stakeholders into
restoration planning. Therefore, this study explores the social construction of wetlands locally, and community members’ perceptions
of the wetland restoration project in the Cache River Watershed of southern Illinois, where public and private agencies have
partnered together to implement a large-scale wetlands restoration project. Findings illustrate that the wetlands hold diverse
and significant meanings to community members and that community members’ criteria for project success may vary from those
identified by project managers. The case study provides managers with strategies for building community commitment such as
engaging local citizens in project planning, minimizing local burdens, maximizing local benefits, and reducing uncertainty. 相似文献
269.
McKinney MA Letcher RJ Aars J Born EW Branigan M Dietz R Evans TJ Gabrielsen GW Peacock E Sonne C 《Environment international》2011,37(2):365-374
Flame retardants and legacy contaminants were analyzed in adipose tissue from 11 circumpolar polar bear (Ursus maritimus) subpopulations in 2005-2008 spanning Alaska east to Svalbard. Although 37 polybrominated diphenyl ethers (PBDEs), total-(α)-hexabromocyclododecane (HBCD), 2 polybrominated biphenyls (PBBs), pentabromotoluene, pentabromoethylbenzene, hexabromobenzene, 1,2-bis(2,4,6-tribromophenoxy(ethane) and decabromodiphenyl ethane were screened, only 4 PBDEs, total-(α-)HBCD and BB153 were consistently found. Geometric mean ΣPBDE (4.6-78.4 ng/g lipid weight (lw)) and BB153 (2.5-81.1 ng/g lw) levels were highest in East Greenland (43.2 and 39.2 ng/g lipid weight (lw), respectively), Svalbard (44.4 and 20.9 ng/g lw) and western (38.6 and 30.1 ng/g lw) and southern Hudson Bay (78.4 and 81.1 ng/g lw). Total-(α)-HBCD levels (<0.3-41.1 ng/g lw) were lower than ΣPBDE levels in all subpopulations except in Svalbard, consistent with greater European HBCD use versus North American pentaBDE product use. ΣPCB levels were high relative to flame retardants as well as other legacy contaminants and increased from west to east (1797-10,537 ng/g lw). ΣCHL levels were highest among legacy organochlorine pesticides and relatively spatially uniform (765-3477 ng/g lw). ΣDDT levels were relatively low and spatially variable (31.5-206 ng/g lw). However, elevated proportions of p,p'-DDT to ΣDDT in Alaska and Beaufort Sea relative to other subpopulations suggested fresh inputs from vector control use in Asia and/or Africa. Comparing earlier circumpolar polar bear studies, ΣPBDE, total-(α)-HBCD, p,p'-DDE and ΣCHL levels consistently declined, whereas levels of other legacy contaminants did not. International regulations have clearly been effective in reducing levels of several legacy contaminants in polar bears relative to historical levels. However, slow or stalling declines of certain historic pollutants like PCBs and a complex mixture of "new" chemicals continue to be of concern to polar bear health and that of their arctic marine ecosystems. 相似文献
270.
Inundation influences on bioavailability of phosphorus in managed wetland sediments in agricultural landscapes 总被引:1,自引:0,他引:1
Kröger R Lizotte RE Douglas Shields F Usborne E 《Journal of environmental quality》2012,41(2):604-614
Agricultural runoff carries high nutrient loads to receiving waters, contributing to eutrophication. Managed wetlands can be used in integrated management efforts to intercept nutrients before they enter downstream aquatic systems, but detailed information regarding sorption and desorption of P by wetland sediments during typical inundation cycles is lacking. This study seeks to quantify and elucidate how inundation of wetland sediments affects bioavailability of P and contributions of P to downstream systems. A managed wetland cell in Tunica County, Mississippi was subjected to a simulated agricultural runoff event and was monitored for bioavailable phosphorus (water-extractable P [P], Fe-P, and Al-P) of wetland sediments and water level during the runoff event and for 130 d afterward. Inundation varied longitudinally within the wetland, with data supporting significant temporal relationships between inundation and P desorption. Concentrations of P were significantly higher at the site that exhibited variable hydroperiods (100 m) as compared with sites under consistent inundation. This suggests that sites that are inundated for longer periods of time desorb less P immediately to the environment than sites that have periodic or ephemeral inundation. Concentrations of iron oxalate and NaOH-P were significantly higher at the least inundated site as compared with all other sites (F = 5.43; = 0.001) irrespective of time. These results support the hypothesis that increased hydraulic residence time decreases the bioavailability of P in wetland sediments receiving agricultural runoff. This finding suggests that the restoration of wetlands in the mid-southern United States may be hydrologically managed to improve P retention. 相似文献