全文获取类型
收费全文 | 4494篇 |
免费 | 77篇 |
国内免费 | 43篇 |
专业分类
安全科学 | 170篇 |
废物处理 | 145篇 |
环保管理 | 722篇 |
综合类 | 762篇 |
基础理论 | 1187篇 |
环境理论 | 11篇 |
污染及防治 | 1074篇 |
评价与监测 | 284篇 |
社会与环境 | 206篇 |
灾害及防治 | 53篇 |
出版年
2023年 | 24篇 |
2022年 | 36篇 |
2021年 | 61篇 |
2020年 | 37篇 |
2019年 | 43篇 |
2018年 | 102篇 |
2017年 | 120篇 |
2016年 | 127篇 |
2015年 | 117篇 |
2014年 | 123篇 |
2013年 | 305篇 |
2012年 | 207篇 |
2011年 | 278篇 |
2010年 | 195篇 |
2009年 | 208篇 |
2008年 | 240篇 |
2007年 | 271篇 |
2006年 | 255篇 |
2005年 | 175篇 |
2004年 | 145篇 |
2003年 | 148篇 |
2002年 | 152篇 |
2001年 | 91篇 |
2000年 | 92篇 |
1999年 | 65篇 |
1998年 | 56篇 |
1997年 | 71篇 |
1996年 | 57篇 |
1995年 | 73篇 |
1994年 | 58篇 |
1993年 | 44篇 |
1992年 | 43篇 |
1991年 | 32篇 |
1990年 | 29篇 |
1989年 | 20篇 |
1988年 | 25篇 |
1987年 | 22篇 |
1986年 | 27篇 |
1985年 | 24篇 |
1984年 | 35篇 |
1983年 | 26篇 |
1982年 | 26篇 |
1981年 | 26篇 |
1980年 | 27篇 |
1979年 | 37篇 |
1978年 | 22篇 |
1977年 | 24篇 |
1976年 | 15篇 |
1975年 | 13篇 |
1957年 | 11篇 |
排序方式: 共有4614条查询结果,搜索用时 46 毫秒
91.
Agricultural economics has, until the 1990s, enjoyeda reputation for relevance and usefulness to theagri-food industry and policy-makers. Thatreputation has been jeopardized by a growinginfatuation with models and quantification, and aconcomitant underemphasis placed on many complexproblems and issues of society. An illustrativeexample is explored, using agriculturalactivity-related damage to the natural resourcebase, environment and ecology. Agriculturaleconomists are urged to respond by broadening theirterms of reference and joining forces with otherdisciplines. 相似文献
92.
Peter W. Colby 《环境质量管理》1997,7(2):61-64
Over the last few years, commentators on all sides of the environmental debate have (with a few exceptions) joined hands to pillory the traditional model of environmental regulation in this country. The catch phrase “command and control” has become emblematic of everything that was seen as being wrong with the old system. The current push for “reinvention” of environmental regulation reinforces the concept that although traditional methods have produced progress, they have outlived their usefulness. At the same time, ISO 14000 has emerged as one of the hottest topics in the environmental field—a form of reinvention of environmental management that has been embraced by many as the solution to an array of problems. While it is still early in the game, initial results indicate that when used effectively, ISO 14000 can be a powerful tool for the environmental manager. However, misuse of ISO 14000 could represent a throwback to command and control rather than a management tool for the new millennium. This article examines how this new tool fits into the evolving picture of environmental regulation and management. 相似文献
93.
Katie D. Smythe J. Christopher Bernabo Thomas B. Carter Peter R. Jutro 《Environmental management》1996,20(6):865-872
The project on Biodiversity Uncertainties and Research Needs (BURN) ensures the advancement of usable knowledge on biodiversity by obtaining input from decision makers on their priority information needs about biodiversity and then using this input to engage leading scientists in designing policy-relevant research. Decision makers articulated concerns related to four issues: significance of biodiversity; status and trends of biodiversity; management for biodiversity; and the linkage of social, cultural, economic, legal, and biological objectives. Leading natural and social scientists then identified the research required to address the decision makers' needs and determined the probability of success. The diverse group of experts reached consensus on several fundamental issues, helping to clarify the role of biodiversity in land and resource management. The BURN participants identified several features that should be incorporated into policy-relevant research plans and management strategies for biodiversity. Research and assessment efforts should be: multidisciplinary and integrative, participatory with stakeholder involvement, hierarchical (multiple scales), and problem- and region-specific. The activities should be focused regionally within a global perspective. Meta-analysis of existing data is needed on all fronts to assess the state of the science. More specifically, the scientists recommended six priority research areas that should be pursued to address the information needs articulated by decision makers: (1) characterization of biodiversity, (2) environmental valuation, (3) management for sustainability—for humans and the environment (adaptive management), (4) information management strategies, (5) governance and stewardship issues, and (6) communication and outreach. Broad recommendations were developed for each research area to provide direction for research planning and resource management strategies. The results will directly benefit those groups that require biodiversity research to address their needs—whether to develop policy, manage natural resources, or make other decisions affecting biodiversity. 相似文献
94.
There are numerous technologies currently being tested by EPA, universities throughout the world, and private research organizations. A few of the more promising innovative technologies as well as fully tested and proven remedies for treating contaminated groundwater are presented in this article. Although several of those technologies have been in existence for only four to five years, the results of full-scale testing are being produced. The method for each of these promising technologies is described, results from recent field-scale studies are summarized, and a discussion of cost is presented. 相似文献
95.
Peter A Hancock 《International journal of occupational safety and ergonomics》2004,10(2):191-195
The following report is a case study example of how problematic information can invade and percolate through the literature on forensic human factors and ergonomics. Initially, a highly doubtful assertion was used to bolster an argument made in a legal case of wrongful death. The assertion was supported through reference to a number of cited works. When the trail of evidence was pursued, however, it became clear that diverse citations had all branched from one, single, original and doubtful source. The fundamental issue, whether children have one third less peripheral vision than adults turns out to be much more complex than the original, simplistic spatial conception suggested. The case study illustrates the importance of ascertaining original citations and is yet another example of the frustration that often accompanies forensic activity where financial and legal concerns frequently over-ride the fundamental search for knowledge. 相似文献
96.
Ryan C. Schwartz Peter J. Deadman Daniel J. Scott Linda D. Mortsch 《Journal of the American Water Resources Association》2004,40(3):647-662
ABSTRACT: Recent research that couples climate change scenarios based on general circulation models (GCM) with Great Lakes hydrologic models has indicated that average water levels are projected to decline in the future. This paper outlines a methodology to assess the potential impact of declining water levels on Great Lakes waterfront communities, using the Lake Huron shoreline at Goderich, Ontario, as an example. The methodology utilizes a geographic information system (GIS) to combine topographic and bathymetric datasets. A digital elevation surface is used to model projected shoreline change for 2050 using water level scenarios. An arbitrary scenario, based on a 1 m decline from February 2001 lake levels, is also modeled. By creating a series of shoreline scenarios, a range of impact and cost scenarios are generated for the Goderich Harbor and adjacent marinas. Additional harbor and marina dredging could cost as much as CDN $7.6 million. Lake freighters may experience a 30 percent loss in vessel capacity. The methodology is used to provide initial estimates of the potential impacts of climate change that can be readily updated as more robust climate change scenarios become available and is adaptable for use in other Great Lakes coastal communities. 相似文献
97.
Marinka D de Groot Tim Bosch Sandra M Eikhout Peter Vink 《International journal of occupational safety and ergonomics》2005,11(3):331-337
A variety of seals is used to close bags. Each seal has advantages and disadvantages. For shop assistants sealing bags could be a repetitive physically demanding action. Opening and closing the bags again can cause some discomfort or annoyance for consumers. Besides, it is an activity which can endanger safety, i.e., knives being used in opening, children swallowing the systems of sealing. To prevent these problems a new sealing system was developed. In this paper the opinion of shop assistants, consumers and experts on several bag sealing systems was studied. It appeared that for sealing plastic bags, adhesive tape with paper is the best out of 4 systems, closely followed by adhesive tape. It is discussed that for the elderly, there is still room for improvement in opening bag seals. 相似文献
98.
Methane oxidation in slurry storage surface crusts 总被引:1,自引:0,他引:1
Livestock manure is a significant source of atmospheric methane (CH4), especially during liquid storage. In liquid manure (slurry) storages a surface crust may form naturally, or an artificial surface crust can be established. We investigated whether there is a potential for CH4 oxidation in this environment. Surface crust materials were sampled from experimental storages with cattle slurry (with natural crust) or anaerobically digested cattle slurry (with straw layer) that had been stored with or without a wooden cover. Extracts of surface crust material were incubated with 5.6% CH4 in the headspace, and methanotrophic activity was demonstrated in all four treatments following a 4- to 10-d lag phase. Subsequent incubation of field-moist surface crust material with 350 microL L(-1) CH4 also showed CH4 oxidation, indicating a potential for CH4 removal under practical storage conditions. There was no CH4 oxidation activity during incubation of autoclaved samples. Methane oxidation rates were 0.1 to 0.5 mg kg(-1) organic matter (OM) h(-1), which is comparable with the activity in wetlands and rice paddies. Partial drying increased CH4 oxidation to 0.2 to 1.4 mg kg(-1) OM h(-1), probably as a result of improved diffusivity within the surface crust. Rewetting reversed the stimulation of methanotrophic activity in some treatments, but not in others, possibly due to a decline in CH4 production in anaerobic volumes, or to growth of methanotrophs during incubation. This study presents direct evidence for methanotrophic activity in slurry storages. Measures to ensure crust formation with or without a solid cover appear to be a cost-effective greenhouse gas mitigation option. 相似文献
99.
Tüzün I Bayramoğlu G Yalçin E Başaran G Celik G Arica MY 《Journal of environmental management》2005,77(2):85-92
The microalgae Chlamydomonas reinhardtii was used for the biosorption of Hg(II), Cd(II) and Pb(II) ions. The maximum adsorption of Hg(II) and Cd(II) ions on Chlamydomonas reinhardtii biomass was observed at pH 6.0 and the corresponding value for Pb(II) ions was 5.0. The biosorption of Hg(II), Cd(II) and Pb(II) ions by microalgae biomass increased as the initial concentration of Hg(II), Cd(II) and Pb(II) ions increased in the biosorption medium. The maximum biosorption capacities of microalgae for Hg(II), Cd(II) and Pb(II) ions were 72.2+/-0.67, 42.6+/-0.54 and 96.3+/-0.86 mg/g dry biomass, respectively. The affinity order for algal biomass was Pb(II)>Hg(II)>Cd(II). FT-IR analysis of algal biomass revealed the presence of amino, carboxyl, hydroxyl and carbonyl groups, which were responsible for biosorption of metal ions. Biosorption equilibrium was established in about 60 min and the equilibrium was well described by the Freundlich biosorption isotherms. Temperature change in the range of 5-35 degrees C did not affect the biosorption capacity. The microalgae could be regenerated using 0.1 M HCl, with up to 98% recovery, which allowed the reuse of the biomass in six biosorption-desorption cycles without any considerable loss of biosorption capacity. 相似文献
100.
This paper reports the findings of a preliminary analysis of 15 case studies of inshore marine protected areas in the UK. It draws on the common-pool resource (CPR) literature and is premised on the thesis that building partnership capacity amongst relevant authorities and resource users provides a critical basis for overcoming collective action problems (CAPs), through the development of incentive structures and social capital, in order to achieve strategic objectives. Particular attention is paid to the influence of statutory marine biodiversity conservation obligations to the European Commission for marine special areas of conservation (MSACs), as these are an important external contextual factor. The risks of imposition and parochialism are outlined and the challenges of taking a balanced approach are discussed. The challenges posed by the attributes of the marine environment are considered, as are those posed by the policy framework for MSACs. The findings are discussed in relation to three questions: (i) which partnership models appear to have the potential to overcome the CAPs posed by inshore MSACs? (ii) what CAPs had to be addressed during the early phase of development of the MSAC co-management regimes? (iii) what are the likely future CAPs for the collaborative management of MSACs that each partnership will need to address? These preliminary findings will form the basis for future studies to analyse the outcomes of these 15 initiatives, in order to assess the strengths, in various contexts, of different approaches for building resilient and balanced, thereby effective, institutions for the co-management of MSACs in the UK. 相似文献