全文获取类型
收费全文 | 27239篇 |
免费 | 238篇 |
国内免费 | 189篇 |
专业分类
安全科学 | 704篇 |
废物处理 | 1023篇 |
环保管理 | 3364篇 |
综合类 | 6939篇 |
基础理论 | 6279篇 |
环境理论 | 9篇 |
污染及防治 | 6546篇 |
评价与监测 | 1500篇 |
社会与环境 | 1160篇 |
灾害及防治 | 142篇 |
出版年
2022年 | 209篇 |
2018年 | 344篇 |
2017年 | 313篇 |
2016年 | 485篇 |
2015年 | 381篇 |
2014年 | 546篇 |
2013年 | 1911篇 |
2012年 | 688篇 |
2011年 | 961篇 |
2010年 | 838篇 |
2009年 | 959篇 |
2008年 | 1013篇 |
2007年 | 1030篇 |
2006年 | 901篇 |
2005年 | 817篇 |
2004年 | 790篇 |
2003年 | 774篇 |
2002年 | 743篇 |
2001年 | 1000篇 |
2000年 | 702篇 |
1999年 | 463篇 |
1998年 | 312篇 |
1997年 | 325篇 |
1996年 | 330篇 |
1995年 | 389篇 |
1994年 | 398篇 |
1993年 | 342篇 |
1992年 | 333篇 |
1991年 | 371篇 |
1990年 | 391篇 |
1989年 | 362篇 |
1988年 | 280篇 |
1987年 | 271篇 |
1986年 | 273篇 |
1985年 | 258篇 |
1984年 | 281篇 |
1983年 | 281篇 |
1982年 | 288篇 |
1981年 | 293篇 |
1980年 | 242篇 |
1979年 | 277篇 |
1978年 | 204篇 |
1977年 | 202篇 |
1976年 | 186篇 |
1975年 | 185篇 |
1974年 | 201篇 |
1973年 | 202篇 |
1972年 | 189篇 |
1967年 | 233篇 |
1966年 | 190篇 |
排序方式: 共有10000条查询结果,搜索用时 422 毫秒
931.
932.
933.
Timothée Schwartz Aurélien Besnard Christophe Pin Olivier Scher Thomas Blanchon Arnaud Béchet Nicolas Sadoul 《Conservation biology》2023,37(2):e14005
By rapidly modifying key habitat components, habitat restoration is at risk of producing attractive cues for animals without providing habitats of sufficient quality. As such, individual fitness components, such as reproduction, could be reduced and restored habitats could become ecological traps. This risk notably appears by using artificial constructions in restoration projects, yet few studies have evaluated their efficacy in a robust way. We investigated this by analyzing 154 islets that were created or restored to improve the conservation status of 7 colonial Laridae species in the South of France. From 2007 to 2016, we compared occupancy dynamics and breeding parameters of these species between the restored sites and 846 unmanaged nesting sites. We also explored species’ preference for different nesting site characteristics and their respective effect on breeding parameters. Restored nesting sites were 2–9 times as attractive as unmanaged sites for all species except the Black-headed Gull (Chroicocephalus ridibundus). Colonization probability was up to 100 times higher in sites already used by other species the previous year and increased with distance to the shore until >0.2 when distance was over 250 m. Abandonment probability was 29–70% lower when breeding was successful the previous year in all species except the Sandwich Tern (Thalasseus sandvicensis). Productivity and breeding success probability were 2 times higher on managed sites. Distance from the shore was an important attractive characteristic of artificial nesting sites in all species. Other nesting site characteristics had species-specific effects on colonization, abandonment, and breeding success. Our results indicate that managed nesting sites are successful conservation tools for colonial Laridae in the Mediterranean and do not act as ecological traps. Our study showed that testing the ecological trap hypothesis is a robust way to evaluate the success of restoration projects of breeding habitats. 相似文献
934.
935.
Aarin Teague Philip B. Bedient Birnur Guven 《Journal of the American Water Resources Association》2011,47(3):620-634
Teague, Aarin, Philip B. Bedient, and Birnur Guven, 2011. Targeted Application of Seasonal Load Duration Curves Using Multivariate Analysis in Two Watersheds Flowing Into Lake Houston. Journal of the American Water Resources Association (JAWRA) 47(3):620‐634. DOI: 10.1111/j.1752‐1688.2011.00529.x Abstract: Water quality is a problem in Lake Houston, the primary source of drinking water for the City of Houston, Texas, due to pollutant loads coming from the influent watersheds, including Spring Creek and Cypress Creek. Statistical analysis of the historic water quality data was developed to understand the source characterization and seasonality of the watershed. Multivariate analysis including principal component, cluster, and discriminant analysis provided a custom seasonal assessment of the watersheds so that loading curves may be targeted for season specific pollutant source characterization. The load duration curves have been analyzed using data collected by the U.S. Geologic Survey with corresponding City of Houston water quality data at the sites to characterize the behavior of the pollutant sources and watersheds. Custom seasons were determined for Spring Creek and Cypress Creek watersheds and pollutant source characterization compared between the seasons and watersheds. 相似文献
936.
‘Bringing the state back in’ to research on comparative, inter-, and trans-national environmental politics and policy will contribute to better understanding of the limits and prospects of contemporary approaches to environmental politics and the overall evolution of contemporary states once environmental issues become central. The rationale for the state as an analytical perspective in environmental policy and politics is explained, and an empirically oriented concept of the environmental state is introduced, along with a tentative sketch of its evolution in historical perspective. A research agenda on the environmental state is mapped out, centring around variation and convergence in environmental states across space and time; the political/economic dynamics of contemporary environmental states; and inter-linkages among environmental problems, the constitution of political communities, and the functioning of the public power. In conclusion, the ways in which the contributions to this volume address that research agenda are introduced. 相似文献
937.
Alexis Laurent Julie Clavreul Anna Bernstad Ioannis Bakas Monia Niero Emmanuel Gentil Thomas H. Christensen Michael Z. Hauschild 《Waste management (New York, N.Y.)》2014,34(3):589-606
Life cycle assessment (LCA) is increasingly used in waste management to identify strategies that prevent or minimise negative impacts on ecosystems, human health or natural resources. However, the quality of the provided support to decision- and policy-makers is strongly dependent on a proper conduct of the LCA. How has LCA been applied until now? Are there any inconsistencies in the past practice? To answer these questions, we draw on a critical review of 222 published LCA studies of solid waste management systems. We analyse the past practice against the ISO standard requirements and the ILCD Handbook guidelines for each major step within the goal definition, scope definition, inventory analysis, impact assessment, and interpretation phases of the methodology. Results show that malpractices exist in several aspects of the LCA with large differences across studies. Examples are a frequent neglect of the goal definition, a frequent lack of transparency and precision in the definition of the scope of the study, e.g. an unclear delimitation of the system boundaries, a truncated impact coverage, difficulties in capturing influential local specificities such as representative waste compositions into the inventory, and a frequent lack of essential sensitivity and uncertainty analyses. Many of these aspects are important for the reliability of the results. For each of them, we therefore provide detailed recommendations to practitioners of waste management LCAs. 相似文献
938.
M.A.S.S. Ravagnani M.H.M. Reis R. Maciel Filho M.R. Wolf-Maciel 《Process Safety and Environmental Protection》2010,88(1):67-73
Production of anhydrous ethanol in large scale has been made by extractive distillation using conventional solvents like ethylene-glycol. In the present paper, extractive distillation process is studied to obtain pure ethanol using ethylene-glycol and tetraethylene-glycol as solvents. Residue curve maps are used to analyse the proposed distillation processes in interpreting mixture behaviours and feasibility of distillation columns. The industrial process is simulated at steady state from residue curve map analysis. Simulation results for the ethanol/water mixture using ethylene-glycol, the conventional solvent, and tetraethylene-glycol, an alternative solvent, are presented. These results showed that the process using tetraethylene-glycol is reliable, although it requires more energy than the process with ethylene-glycol. However, ethylene-glycol has a considerable toxicity level while tetraethylene-glycol is non-toxic. 相似文献
939.
Anders Damgaard Christian Riber Thilde Fruergaard Tore Hulgaard Thomas H. Christensen 《Waste management (New York, N.Y.)》2010,30(7):1244-1250
Incineration of municipal solid waste is a debated waste management technology. In some countries it is the main waste management option whereas in other countries it has been disregarded. The main discussion point on waste incineration is the release of air emissions from the combustion of the waste, but also the energy recovery efficiency has a large importance.The historical development of air pollution control in waste incineration was studied through life-cycle-assessment modelling of eight different air pollution control technologies. The results showed a drastic reduction in the release of air emissions and consequently a significant reduction in the potential environmental impacts of waste incineration. Improvements of a factor 0.85–174 were obtained in the different impact potentials as technology developed from no emission control at all, to the best available emission control technologies of today (2010).The importance of efficient energy recovery was studied through seven different combinations of heat and electricity recovery, which were modelled to substitute energy produced from either coal or natural gas. The best air pollution control technology was used at the incinerator. It was found that when substituting coal based energy production total net savings were obtained in both the standard and toxic impact categories. However, if the substituted energy production was based on natural gas, only the most efficient recovery options yielded net savings with respect to the standard impacts. With regards to the toxic impact categories, emissions from the waste incineration process were always larger than those from the avoided energy production based on natural gas. The results shows that the potential environmental impacts from air emissions have decreased drastically during the last 35 years and that these impacts can be partly or fully offset by recovering energy which otherwise should have been produced from fossil fuels like coal or natural gas. 相似文献
940.
Patrick T.I. Lam Edwin H.W. Chan C.S. Poon C.K. Chau K.P. Chun 《Journal of environmental management》2010,91(3):654-661
Green specifications constitute one of the important elements in green construction. New sustainability requirements and changing priorities in construction management have spurred the emerging green specifications to a faster pace of development. A cross-sectional survey has been conducted in Hong Kong in 2007 to identify principal factors leading to the success of preparing green specifications. Based on extensive construction management literature, 20 variables concerning sustainable construction were summarized. Using the Mann–Whitney U-test, the subtle differences between stakeholders in specifying construction work have been detected even with the high consistency of the responses among the groups. Moreover, five independent factors for successful specification of green construction have been categorized by factor analysis. They are related to (1) green technology and techniques, (2) reliability and quality of specification, (3) leadership and responsibility, (4) stakeholder involvement, and (5) guide and benchmarking systems. Whilst the first and fourth factors are generally more important, different stakeholder groups have different emphases. The results of the survey have been validated against established principles. 相似文献