全文获取类型
收费全文 | 455篇 |
免费 | 13篇 |
国内免费 | 9篇 |
专业分类
安全科学 | 25篇 |
废物处理 | 19篇 |
环保管理 | 78篇 |
综合类 | 114篇 |
基础理论 | 88篇 |
污染及防治 | 82篇 |
评价与监测 | 46篇 |
社会与环境 | 23篇 |
灾害及防治 | 2篇 |
出版年
2023年 | 3篇 |
2022年 | 6篇 |
2021年 | 9篇 |
2020年 | 5篇 |
2019年 | 5篇 |
2018年 | 13篇 |
2017年 | 6篇 |
2016年 | 21篇 |
2015年 | 13篇 |
2014年 | 10篇 |
2013年 | 30篇 |
2012年 | 12篇 |
2011年 | 23篇 |
2010年 | 23篇 |
2009年 | 27篇 |
2008年 | 21篇 |
2007年 | 24篇 |
2006年 | 16篇 |
2005年 | 18篇 |
2004年 | 28篇 |
2003年 | 23篇 |
2002年 | 14篇 |
2001年 | 10篇 |
2000年 | 7篇 |
1998年 | 4篇 |
1997年 | 3篇 |
1995年 | 5篇 |
1991年 | 3篇 |
1989年 | 4篇 |
1988年 | 4篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1983年 | 2篇 |
1980年 | 3篇 |
1979年 | 3篇 |
1978年 | 2篇 |
1977年 | 5篇 |
1972年 | 4篇 |
1970年 | 4篇 |
1968年 | 2篇 |
1966年 | 3篇 |
1965年 | 3篇 |
1964年 | 6篇 |
1963年 | 2篇 |
1961年 | 2篇 |
1960年 | 5篇 |
1958年 | 4篇 |
1957年 | 2篇 |
1956年 | 3篇 |
1953年 | 4篇 |
排序方式: 共有477条查询结果,搜索用时 250 毫秒
151.
Tony Svejcar Chad Boyd Kirk Davies Matthew Madsen Jon Bates Roger Sheley Clayton Marlow David Bohnert Mike Borman Ricardo Mata-Gonzàlez John Buckhouse Tamzen Stringham Barry Perryman Sherman Swanson Kenneth Tate Mel George George Ruyle Bruce Roundy Chris Call Kevin Jensen Karen Launchbaugh Amanda Gearhart Lance Vermeire John Tanaka Justin Derner Gary Frasier Kris Havstad 《Environmental management》2014,53(6):1035-1038
In a previous article, Beschta et al. (Environ Manag 51(2):474–491, 2013) argue that grazing by large ungulates (both native and domestic) should be eliminated or greatly reduced on western public lands to reduce potential climate change impacts. The authors did not present a balanced synthesis of the scientific literature, and their publication is more of an opinion article. Their conclusions do not reflect the complexities associated with herbivore grazing. Because grazing is a complex ecological process, synthesis of the scientific literature can be a challenge. Legacy effects of uncontrolled grazing during the homestead era further complicate analysis of current grazing impacts. Interactions of climate change and grazing will depend on the specific situation. For example, increasing atmospheric CO2 and temperatures may increase accumulation of fine fuels (primarily grasses) and thus increase wildfire risk. Prescribed grazing by livestock is one of the few management tools available for reducing fine fuel accumulation. While there are certainly points on the landscape where herbivore impacts can be identified, there are also vast grazed areas where impacts are minimal. Broad scale reduction of domestic and wild herbivores to help native plant communities cope with climate change will be unnecessary because over the past 20–50 years land managers have actively sought to bring populations of native and domestic herbivores in balance with the potential of vegetation and soils. To cope with a changing climate, land managers will need access to all available vegetation management tools, including grazing. 相似文献
152.
Kristell A. Miller Stephanie A. Snyder Mike A. Kilgore Mae A. Davenport 《Environmental management》2014,54(6):1399-1411
In 2012, focus groups were organized with individuals owning 20+ acres in the Lake States region of the United States (Michigan, Minnesota, and Wisconsin) to discuss various issues related to forest carbon offsetting. Focus group participants consisted of landowners who had responded to an earlier mail-back survey (2010) on forest carbon offsets. Two focus groups were held per state with an average of eight participants each (49 total). While landowner participant types varied, overall convergence was reached on several key issues. In general, discussion results found that the current payment amounts offered for carbon credits are not likely, on their own, to encourage participation in carbon markets. Landowners are most interested in other benefits they can attain through carbon management (e.g., improved stand species mix, wildlife, and trails). Interestingly, landowner perceptions about the condition of their own forest land were most indicative of prospective interest in carbon management. Landowners who felt that their forest was currently in poor condition, or did not meet their forest ownership objectives, were most interested in participating. While the initial survey sought landowner opinions about carbon markets, a majority of focus group participants expressed interest in general carbon management as a means to achieve reduced property taxes. 相似文献
153.
The 2008 Disaster Mitigation Preparedness (DMP) study took place in Aceh province, Indonesia. It sought to help develop radio programmes and messages to increase resilience to disasters. The role of radio was evaluated during and after the 2004 Asian tsunami disaster. The study team interviewed 984 tsunami survivors from nine sub-districts of Banda Aceh, and local nongovernmental organisations convened eight focus groups around the area of Aceh Besar. Six key informant interviews were held with government disaster management agencies. The DMP survey is the first of its kind to interview a representative random sample of Banda Aceh residents. It reveals the importance of community and social networks, during disaster situations, when essential communications are down. A disaster warning information system based on a multi-media approach needs to be developed. The wider community should be involved in the planning, education and training of Banda Aceh and Aceh Besar residents to facilitate appropriate personal and community survival strategies. 相似文献
154.
Meyer B Pailler JY Guignard C Hoffmann L Krein A 《Environmental monitoring and assessment》2011,180(1-4):127-146
Urban and agricultural areas affect the hydraulic patterns as well as the water quality of receiving drainage systems, especially of catchments smaller than 50 km(2). Urban runoff is prone to contamination due to pollutants like pesticides or pharmaceuticals. Agricultural areas are possible sources of nutrient and herbicide contamination for receiving water bodies. The pollution is derived from leaching by subsurface flow, as well as wash-off and erosion caused by surface runoff. In the Luxembourgish Mess River catchment, the pharmaceutical and pesticide concentrations are comparable with those detected by other authors in different river systems worldwide. Some investigated pesticide concentrations infringe current regulations. The maximum allowable concentration for diuron of 1.8 μg l(?-?1) is exceeded fourfold by measured 7.41 μg l(?-?1) in a flood event. The load of dissolved pesticides reaching the stream gauge is primarily determined by the amount applied to the surfaces within the catchment area. Storm water runoff from urban areas causes short-lived but high-pollutant concentrations and moderate loads, whereas moderate concentrations and high loads are representative for agricultural inputs to the drainage system. Dissolved herbicides, sulfonamides, tetracyclines, analgesics and hormones can be used as indicators to investigate runoff generation processes, including inputs from anthropogenic sources. The measurements prove that the influence of kinematic wave effects on the relationship between hydrograph and chemographs should not be neglected in smaller basins. The time lag shows that it is not possible to connect analysed substances of defined samples to the corresponding section of the hydrograph. 相似文献
155.
156.
157.
Various governmental regulatory agencies are responsible for establishing regulations on the discharge of chlorinated organic
compounds from pulp and paper mills. The procedures for setting permit limits are the basic topic of this article. Different
methods of determining permit limits are set forth and discussed in a number of references, including documents of the Environmental
Protection Agency. This paper discusses in detail the application of one particular methodology—the lognormal model approach.
In this paper we utilize a real data set and include the necessary calculations required to set up permit limits.
The basic tenets of the permit process are such that if limits are set too low, operators who are in full regulatory compliance
will still be frequently cited, and if limits are set too high, operators who are not in compliance will seldom if ever be
cited. Thus there is a great need for these effluent limits to be determined with great care, both to protect the environment
receiving the wastewater and the industry producing the wastewater. 相似文献
158.
159.
Alister Scott Mike Christie Helen Tench 《Journal of Environmental Planning and Management》2003,46(4):583-604
This paper assesses the efficacy and relevance of visitor payback as a tool for recreation management in the UK. Visitor payback is essentially a voluntary payment made by visitors towards conservation, differing significantly from the compulsory tourist or bed tax practised in other countries. Attention has recently focused on this technique as a means to supplement the limited funds available for conservation work. However, whilst there are several schemes operating in the UK, there is a dearth of published research that has critically reviewed the concept and operationalization of visitor payback. The research reported here utilizes primary and secondary data to include case studies, semi-structured interviews and focus groups. The findings reveal that visitor payback is a complex concept to evaluate, both in theory and practice, involving a range of benefits and disbenefits. Financial benefits appear less prevalent than the more esoteric ‘feel good’ factor, increased awareness about conservation and partnerships that are evident in payback schemes. Support for visitor payback varies considerably with visitors strongly receptive, whilst the tourism business interests are more cautious. It is concluded that visitor payback needs to be re-conceptualized in more positive terms as a ‘visitor investment scheme’ where conservation takes precedence over financial considerations. Further research is required to try and demystify the tourism business resistance to visitor payback as its potential seems somewhat constrained in the present climate. 相似文献
160.
After fusion of somatic cells (isolated protoplasts) of Arabidopsis thaliana and Brassica campestris, plants could be regenerated in which genetic material from parents of taxonomically different tribes is combined. Between these regenerants asymmetric hybrids have also been obtained, in which one parental genome is represented by reduced chromosome numbers. Results concerning the analysis and genesis of these plants are used to discuss the question whether such monster plants are of any importance. 相似文献