全文获取类型
收费全文 | 2548篇 |
免费 | 74篇 |
国内免费 | 24篇 |
专业分类
安全科学 | 181篇 |
废物处理 | 151篇 |
环保管理 | 541篇 |
综合类 | 298篇 |
基础理论 | 586篇 |
环境理论 | 3篇 |
污染及防治 | 580篇 |
评价与监测 | 179篇 |
社会与环境 | 92篇 |
灾害及防治 | 35篇 |
出版年
2023年 | 11篇 |
2022年 | 19篇 |
2021年 | 27篇 |
2020年 | 26篇 |
2019年 | 26篇 |
2018年 | 61篇 |
2017年 | 58篇 |
2016年 | 76篇 |
2015年 | 72篇 |
2014年 | 70篇 |
2013年 | 231篇 |
2012年 | 108篇 |
2011年 | 148篇 |
2010年 | 114篇 |
2009年 | 131篇 |
2008年 | 127篇 |
2007年 | 143篇 |
2006年 | 133篇 |
2005年 | 97篇 |
2004年 | 85篇 |
2003年 | 107篇 |
2002年 | 71篇 |
2001年 | 54篇 |
2000年 | 53篇 |
1999年 | 41篇 |
1998年 | 39篇 |
1997年 | 34篇 |
1996年 | 33篇 |
1995年 | 26篇 |
1994年 | 34篇 |
1993年 | 31篇 |
1992年 | 21篇 |
1991年 | 24篇 |
1990年 | 13篇 |
1989年 | 11篇 |
1988年 | 16篇 |
1987年 | 19篇 |
1986年 | 13篇 |
1985年 | 19篇 |
1984年 | 12篇 |
1983年 | 18篇 |
1982年 | 19篇 |
1981年 | 24篇 |
1980年 | 13篇 |
1979年 | 10篇 |
1978年 | 6篇 |
1977年 | 9篇 |
1971年 | 6篇 |
1957年 | 5篇 |
1955年 | 5篇 |
排序方式: 共有2646条查询结果,搜索用时 31 毫秒
991.
Rousseau AN Lafrance P Lavigne MP Savary S Konan B Quilbé R Jiapizian P Amrani M 《Journal of environmental quality》2012,41(1):52-63
This paper proposes a hydrological modeling framework to define achievable performance standards (APSs) for pesticides that could be attained after implementation of recommended management actions, agricultural practices, and available technologies (i.e., beneficial management practices [BMPs]). An integrated hydrological modeling system, Gestion Intégrée des Bassins versants à l'aide d'un Système Informatisé, was used to quantify APSs for six Canadian watersheds for eight pesticides: atrazine, carbofuran, dicamba, glyphosate, MCPB, MCPA, metolachlor, and 2,4-D. Outputs from simulation runs to predict pesticide concentration under current conditions and in response to implementation of two types of beneficial management practices (reduced pesticide application rate and 1- to 10-m-wide edge-of-field and/or riparian buffer strips, implemented singly or in combination) showed that APS values for scenarios with BMPs were less than those for current conditions. Moreover, APS values at the outlet of watersheds were usually less than ecological thresholds of good condition, when available. Upstream river reaches were at greater risk of having concentrations above a given ecological thresholds because of limited stream flows and overland loads of pesticides. Our integrated approach of "hydrological modeling-APS estimation-ecotoxicological significance" provides the most effective interpretation possible, for management and education purposes, of the potential biological impact of predicted pesticide concentrations in rivers. 相似文献
992.
The growing importance of the environment and its management has simultaneously emphasized the benefits of hydroelectric power and its environmental costs. In a changing policy climate, giving importance to renewable energy development and environmental protection, conflict potential between stakeholders is considerable. Navigation of conflict determines the scheme constructed, making sustainable hydropower a function of human choice. To meet the needs of practitioners, greater understanding of stakeholder conflict is needed. This paper presents an approach to illustrate the challenges that face small-scale hydropower development as perceived by the stakeholders involved, and how they influence decision-making. Using Gordleton Mill, Hampshire (UK), as an illustrative case, soft systems methodology, a systems modeling approach, was adopted. Through individual interviews, a range of problems were identified and conceptually modeled. Stakeholder bias towards favoring economic appraisal over intangible social and environmental aspects was identified; costs appeared more influential than profit. Conceptual evaluation of the requirements to meet a stakeholder-approved solution suggested a complex linear systems approach, considerably different from the real-life situation. The stakeholders introduced bias to problem definition by transferring self-perceived issues onto the project owner. Application of soft systems methodology caused a shift in project goals away from further investigation towards consideration of project suitability. The challenge of sustainable hydropower is global, with a need to balance environmental, economic, and social concerns. It is clear that in this type of conflict, an individual can significantly influence outcomes; highlighting the need for more structured approaches to deal with stakeholder conflicts in sustainable hydropower development. 相似文献
993.
Paul B. Thompson Kyle Powys Whyte 《Journal of Agricultural and Environmental Ethics》2012,25(4):485-498
What is the significance of the wicked problems framework for environmental philosophy? In response to wicked problems, environmental scientists are starting to welcome the participation of social scientists, humanists, and the creative arts. We argue that the need for interdisciplinary approaches to wicked problems opens up a number of tasks that environmental philosophers have every right to undertake. The first task is for philosophers to explore new and promising ways of initiating philosophical research through conducting collaborative learning processes on environmental issues. The second task is for philosophers to recognize the value of philosophical skills in their engagements with members of other disciplines and walks of life in addressing wicked problems. The wicked problems framework should be seen as an important guide for facilitating philosophical research that is of relevance to problems like climate change and sustainable agriculture. 相似文献
994.
Planetary Stewardship in an Urbanizing World: Beyond City Limits 总被引:1,自引:0,他引:1
Sybil P. Seitzinger Uno Svedin Carole L. Crumley Will Steffen Saiful Arif Abdullah Christine Alfsen Wendy J. Broadgate Frank Biermann Ninad R. Bondre John A. Dearing Lisa Deutsch Shobhakar Dhakal Thomas Elmqvist Neda Farahbakhshazad Owen Gaffney Helmut Haberl Sandra Lavorel Cheikh Mbow Anthony J. McMichael Joao M. F. deMorais Per Olsson Patricia Fernanda Pinho Karen C. Seto Paul Sinclair Mark Stafford Smith Lorraine Sugar 《Ambio》2012,41(8):787-794
Cities are rapidly increasing in importance as a major factor shaping the Earth system, and therefore, must take corresponding responsibility. With currently over half the world’s population, cities are supported by resources originating from primarily rural regions often located around the world far distant from the urban loci of use. The sustainability of a city can no longer be considered in isolation from the sustainability of human and natural resources it uses from proximal or distant regions, or the combined resource use and impacts of cities globally. The world’s multiple and complex environmental and social challenges require interconnected solutions and coordinated governance approaches to planetary stewardship. We suggest that a key component of planetary stewardship is a global system of cities that develop sustainable processes and policies in concert with its non-urban areas. The potential for cities to cooperate as a system and with rural connectivity could increase their capacity to effect change and foster stewardship at the planetary scale and also increase their resource security. 相似文献
995.
Duarte CM Agustí S Wassmann P Arrieta JM Alcaraz M Coello A Marbà N Hendriks IE Holding J García-Zarandona I Kritzberg E Vaqué D 《Ambio》2012,41(1):44-55
The Arctic marine ecosystem contains multiple elements that present alternative states. The most obvious of which is an Arctic Ocean largely covered by an ice sheet in summer versus one largely devoid of such cover. Ecosystems under pressure typically shift between such alternative states in an abrupt, rather than smooth manner, with the level of forcing required for shifting this status termed threshold or tipping point. Loss of Arctic ice due to anthropogenic climate change is accelerating, with the extent of Arctic sea ice displaying increased variance at present, a leading indicator of the proximity of a possible tipping point. Reduced ice extent is expected, in turn, to trigger a number of additional tipping elements, physical, chemical, and biological, in motion, with potentially large impacts on the Arctic marine ecosystem. 相似文献
996.
The contamination status of the marine environment in Hong Kong was studied by measuring concentrations of organochlorine (OC) pollutants (i.e., hexachlorobenzene, aldrin, dieldrin, endrin, mirex, total heptachlor, total chlordane, total DDTs, total PCBs, and total toxaphenes) in the eggs of selected waterbird species from different locations around the city: Little Egret (Egretta garzetta) and Chinese Pond Heron (Ardeola bacchus) from Mai Po Village, Great Egret (Ardea alba) and Black-crowned Night Heron (Nycticorax nycticorax) from A Chau, and Chinese Pond Heron (A. bacchus) from Ho Sheung Heung. The mean concentrations of total PCBs and total DDTs ranged from 191-11 100 ng g−1 lipid and 453-49 000 ng g−1 lipid, respectively. Recent exposure of waterbirds to technical chlordane was found in Hong Kong. The risk characterization demonstrated potential risks to birds associated with exposure to DDE, which was found to cause a reduction in survival of young in Hong Kong Ardeids based on the endpoint in the risk assessment. 相似文献
997.
The yield of PCDD/F in relation to the presence of oxygenated PAH in model waste incinerator flyash has been investigated in a fixed bed laboratory scale reactor. Experiments were undertaken by thermal treatment of the model flyash at 250 and 350 °C under a simulated flue gas stream for 2 h. After reaction, the PCDD/F content of the reacted flyash and the PCDD/F released into the exhaust gas, and subsequently trapped by XAD-II resin in a down-stream condensation system were analyzed. The PAHs investigated were, dibenzofuran and benzo[b]naphtho[2,3-d]furan and were spiked onto the model flyash as reactant precursors for PCDD/F formation. The results showed significant formation of furans from both of the PAH investigated, however except from some highly chlorinated dioxin congeners, the formation of dioxins was not so common. Benzonaphthofuran was significantly more reactive than dibenzofuran in PCDD/F formation, in spite of the fact that dibenzofuran is structurally more similar to that of PCDD/F. Thus, there was no clear attribution between the chemical structure of PAH used and the formation of PCDD/F. There were considerable differences between the yields of PCDD/F congeners in the gaseous species and those in the reacted flyash under the same operational conditions. The concentration of PCDD/Fs was reduced at the higher reaction temperature of 350 °C; however, the higher temperature resulted in the majority of the PCDD/F formed on the flyash being released into the gas phase. 相似文献
998.
Dybowska AD Croteau MN Misra SK Berhanu D Luoma SN Christian P O'Brien P Valsami-Jones E 《Environmental pollution (Barking, Essex : 1987)》2011,159(1):266-273
Understanding the behavior of engineered nanoparticles in the environment and within organisms is perhaps the biggest obstacle to the safe development of nanotechnologies. Reliable tracing is a particular issue for nanoparticles such as ZnO, because Zn is an essential element and a common pollutant thus present at elevated background concentrations. We synthesized isotopically enriched (89.6%) with a rare isotope of Zn (67Zn) ZnO nanoparticles and measured the uptake of 67Zn by L. stagnalis exposed to diatoms amended with the particles. Stable isotope technique is sufficiently sensitive to determine the uptake of Zn at an exposure equivalent to lower concentration range (<15 μg g−1). Without a tracer, detection of newly accumulated Zn is significant at Zn exposure concentration only above 5000 μg g−1 which represents some of the most contaminated Zn conditions. Only by using a tracer we can study Zn uptake at a range of environmentally realistic exposure conditions. 相似文献
999.
The distribution pattern and fractionation of arsenic (As) in three soil profiles from tea (Camellia sinensis L.) gardens located in Karbi-Anglong (KA), Cachar (CA) and Karimganj (KG) districts in the state of Assam, India, were investigated depth-wise (0-10, 10-30, 30-60 and 60-100 cm). DTPA-extractable As was primarily restricted to surface horizons. Arsenic speciation study showed the presence of higher As(V) concentrations in the upper horizon and its gradual decrease with the increase in soil depths, following a decrease of Eh. As fractionation by sequential extraction in all the soil profiles showed that arsenic concentrations in the three most labile fractions (i.e., water-soluble, exchangeable and carbonate-bound fractions) were generally low. Most arsenic in soils was nominally associated with the organic and Fe-Mn oxide fractions, being extractable in oxidizing or reducing conditions. DTPA-extractable As (assumed to represent plant-available As) was found to be strongly correlated to the labile pool of As (i.e. the sum of the first three fractions). The statistical comparison of means (two-sample t-test) showed the presence of significant differences between the concentrations of As(III) and As(V) for different soil locations, depths and fractions. The risk assessment code (RAC) was found to be below the pollution level for all soils. The measurement of arsenic uptake by different parts of tea plants corroborated the hypothesis that roots act as a buffer and hold back contamination from the aerial parts. 相似文献
1000.
Naile JE Khim JS Wang T Wan Y Luo W Hu W Jiao W Park J Ryu J Hong S Jones PD Lu Y Giesy JP 《Environmental pollution (Barking, Essex : 1987)》2011,159(4):907-917
Polychlorinated-dibenzo-p-dioxins and -dibenzofurans (PCDD/Fs) were measured in soils and sediments from the Yellow Sea region. Korean soils and sediments mostly contained detectable PCDD/Fs and showed a widespread distribution among locations. Soil and sedimentary PCDD/Fs from China were comparable to or less than those in Korea. The patterns of relative concentrations of individual congeners in soils were different between the two countries, but similar in sediments. Sources of PCDD/Fs in China and Korea were found to be independent of each other and their distributions reflected matrix-dependent accumulation. Spatial distribution indicated some point sources in Korea while Chinese sources were more widespread and diffuse. PCDD/Fs measured in the coastal areas of the Yellow Sea were comparable to or less than those previously reported in for eastern Asia. However, ∑TEQs in soils and sediments were near to or, in some cases exceeded environmental quality guidelines. 相似文献