全文获取类型
收费全文 | 687篇 |
免费 | 19篇 |
国内免费 | 6篇 |
专业分类
安全科学 | 36篇 |
废物处理 | 27篇 |
环保管理 | 103篇 |
综合类 | 122篇 |
基础理论 | 150篇 |
环境理论 | 2篇 |
污染及防治 | 182篇 |
评价与监测 | 45篇 |
社会与环境 | 37篇 |
灾害及防治 | 8篇 |
出版年
2024年 | 1篇 |
2023年 | 19篇 |
2022年 | 16篇 |
2021年 | 20篇 |
2020年 | 25篇 |
2019年 | 15篇 |
2018年 | 28篇 |
2017年 | 33篇 |
2016年 | 45篇 |
2015年 | 32篇 |
2014年 | 41篇 |
2013年 | 56篇 |
2012年 | 55篇 |
2011年 | 47篇 |
2010年 | 35篇 |
2009年 | 35篇 |
2008年 | 24篇 |
2007年 | 33篇 |
2006年 | 25篇 |
2005年 | 22篇 |
2004年 | 16篇 |
2003年 | 12篇 |
2002年 | 12篇 |
2001年 | 6篇 |
2000年 | 6篇 |
1999年 | 5篇 |
1998年 | 10篇 |
1997年 | 2篇 |
1996年 | 4篇 |
1995年 | 4篇 |
1994年 | 3篇 |
1993年 | 4篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 4篇 |
1985年 | 2篇 |
1984年 | 3篇 |
1981年 | 1篇 |
1972年 | 1篇 |
1964年 | 1篇 |
排序方式: 共有712条查询结果,搜索用时 31 毫秒
241.
242.
Daren R. Harmel Laura E. Christianson Matthew W. McBroom Douglas R. Smith Kori D. Higgs 《Journal of the American Water Resources Association》2016,52(5):1275-1279
The “Measured Annual Nutrient loads from AGricultural Environments” (MANAGE) database was published in 2006 to expand an early 1980s compilation of nutrient export (load) data from cultivated and pasture/range land at the field or farm scale. Then in 2008, MANAGE was updated with 15 additional studies, and nitrogen (N) and phosphorus (P) concentrations in runoff were added. Since then, MANAGE has undergone significant expansion adding N and P water quality along with relevant management and site characteristic data from: (1) 30 runoff studies from forested land uses, (2) 91 drainage water quality studies from drained land, and (3) 12 additional runoff studies from cultivated and pasture/range land uses. In this expansion, an application timing category was added to the existing fertilizer data categories (rate, placement, formulation) to facilitate analysis of 4R Nutrient Stewardship, which emphasizes right fertilizer source, rate, time, and place. In addition, crop yield and N and P uptake data were added, although this information was only available for 21 and 7% of studies, respectively. Inclusion of these additional data from cultivated, pasture/range, and forest land uses as well as artificially drained agricultural land should facilitate expanded spatial analyses and improved understanding of regional differences, management practice effectiveness, and impacts of land use conversions and management techniques. The current version is available at www.ars.usda.gov/spa/manage-nutrient . 相似文献
243.
We studied the effects of catchment characteristics (soil type and land use) on the concentration and quality of dissolved organic matter (DOM) in river water and on the bacterial degradation of terrestrial DOM. The share of organic soil was the strongest predictor of high concentrations of dissolved organic carbon, nitrogen, and phosphorus (DOC, DON, and DOP, respectively), and was linked to DOM quality. Soil type was more important than land use in determining the concentration and quality of riverine DOM. On average, 5–9 % of the DOC and 45 % of the DON were degraded by the bacterial communities within 2–3 months. Simultaneously, the proportion of humic-like compounds in the DOM pool increased. Bioavailable DON accounted for approximately one-third of the total bioavailable dissolved nitrogen, and thus, terrestrial DON can markedly contribute to the coastal plankton dynamics and support the heterotrophic food web. 相似文献
244.
Sara Maestre-Andrés Laura Calvet-Mir Jeroen C. J. M. van den Bergh 《Regional Environmental Change》2016,16(3):717-731
The notion of ecosystem services is considered useful for integrating perceptions and values into decision-making on environment and nature. Sociocultural factors have been suggested to explain perceptions and values assigned to ecosystem services. We examine this by undertaking a sociocultural valuation of ecosystem services provided by the natural park of Sant Llorenç del Munt, located at the edge of the Barcelona Metropolitan Region. Four methods are used, namely a review of the literature on ecosystem services, non-participant observation, semi-structured interviews with stakeholders and a valuation survey among visitors. We assess whether visitors and other stakeholders understand the term ecosystem service, finding that the concept is rather unknown or misunderstood. Among the 28 ecosystem services identified, habitat and cultural services were the most valued. We statistically identify socioeconomic characteristics of visitors that have a main influence on their valuation of ecosystem services. We further assess diverging preferences of all stakeholders that might give rise to conflicting views about policies for protected areas. We draw lessons about the usefulness of the multi-method approach and about the management of protected areas. 相似文献
245.
Thomas K. Rudel Birthe Paul Douglas White I. M. Rao Rein Van Der Hoek Aracely Castro Maryline Boval Amy Lerner Laura Schneider Michael Peters 《Ambio》2015,44(7):685-693
The increased use of grain-based feed for livestock during the last two decades has contributed, along with other factors, to a rise in grain prices that has reduced human food security. This circumstance argues for feeding more forages to livestock, particularly in the tropics where many livestock are reared on small farms. Efforts to accomplish this end, referred to as the ‘LivestockPlus’ approach, intensify in sustainable ways the management of grasses, shrubs, trees, and animals. By decoupling the human food and livestock feed systems, these efforts would increase the resilience of the global food system. Effective LivestockPlus approaches take one of two forms: (1) simple improvements such as new forage varieties and animal management practices that spread from farmer to farmer by word of mouth, or (2) complex sets of new practices that integrate forage production more closely into farms’ other agricultural activities and agro-ecologies. 相似文献
246.
Human societies derive economic benefit from marine systems, yet these benefits may be modified as humans drive environmental change. Here, we conducted the first systematic review of literature on the potential economic effects of ocean acidification. We identified that while there is a growing literature discussing this topic, assessments of the direction and magnitude of anticipated economic change remain limited. The few assessments which have been conducted indicate largely negative economic effects of ocean acidification. Insights are, however, limited as the scope of the studies remains restricted. We propose that understanding of this topic will benefit from using standard approaches (e.g. timescales and emissions scenarios) to consider an increasing range of species/habitats and ecosystem services over a range of spatial scales. The resulting understanding could inform decisions such that we maintain, or enhance, economic services obtained from future marine environments. 相似文献
247.
Luciene Alves Batista Siniscalchi Laura Rabelo Leite Guilherme Oliveira Carlos Augusto Lemos Chernicharo Juliana Calabria de Araújo 《Environmental science and pollution research international》2017,24(20):16751-16764
Methane is produced in anaerobic environments, such as reactors used to treat wastewaters, and can be consumed by methanotrophs. The composition and structure of a microbial community enriched from anaerobic sewage sludge under methane-oxidation condition coupled to denitrification were investigated. Denaturing gradient gel electrophoresis (DGGE) analysis retrieved sequences of Methylocaldum and Chloroflexi. Deep sequencing analysis revealed a complex community that changed over time and was affected by methane concentration. Methylocaldum (8.2%), Methylosinus (2.3%), Methylomonas (0.02%), Methylacidiphilales (0.45%), Nitrospirales (0.18%), and Methanosarcinales (0.3%) were detected. Despite denitrifying conditions provided, Nitrospirales and Methanosarcinales, known to perform anaerobic methane oxidation coupled to denitrification (DAMO) process, were in very low abundance. Results demonstrated that aerobic and anaerobic methanotrophs coexisted in the reactor together with heterotrophic microorganisms, suggesting that a diverse microbial community was important to sustain methanotrophic activity. The methanogenic sludge was a good inoculum to enrich methanotrophs, and cultivation conditions play a selective role in determining community composition. 相似文献
248.
Water Use for Hydraulic Fracturing of Oil and Gas in the South Platte River Basin,Colorado 下载免费PDF全文
Ella L. Walker Aspen M. Anderson Laura K. Read Terri S. Hogue 《Journal of the American Water Resources Association》2017,53(4):839-853
Water use for oil and gas development (i.e., hydraulic fracturing) is a concern in semiarid basins where water supply is often stressed to meet demands, and oil and gas production can exacerbate the situation. Understanding the impacts of water use for hydraulic fracturing (HF) on water availability in semiarid regions is critical for management and regulatory decisions. In the current work, we quantify water use for HF at several scales — from municipal to state‐wide — using the IHS Enerdeq database for the South Platte Basin. In addition, we estimate produced water (a by‐product of oil and gas production), using data from the Colorado Oil and Gas Conservation Commission to explore reuse scenarios. The South Platte River Basin, located in northeastern Colorado, encompasses the Denver‐Metro area. The basin has one of the most productive oil and gas shale formations in Colorado, with much of the production occurring in Weld County. The basin has experienced higher horizontal drilling rates coupled with an increasing population. Results show water use for horizontal and vertical wells averages 11,000 and 1,000 m3, respectively. Water use for HF in the South Platte Basin totaled 0.63% of the basin's 2014 total water demand. For Weld County, water use for HF was 2.4% of total demand, and for the city of Greeley, water use was 7% of total demand. Produced water totaled 9.4 Mm3 in the basin for 2014, which represents 42% of the total water used for HF. 相似文献
249.
Transdisciplinarity (TD) has become a buzzword, promoted as a suitable approach to address today’s urgent challenges in human-environment interactions. Looking at its practical implementation, however, challenges still remain to be met. Despite the concept’s popularity, it seems difficult to reconcile the idea of knowledge co-production with research realities. Taking a TD research project dealing with sustainable land management in Southern Africa (Angola, Botswana, and Namibia) as a case study, we aim to provide empirically based insights into the real-world application of this collaborative research approach to improve the general understanding of TD research in the making. Based on semi-structured interviews with project partners and stakeholders, we reveal the underlying interests, mismatching institutions and structures of power shaping the TD research process in this North–South collaboration. We identified TD as falling victim to a kind of “tragedy of the commons”, paralysed between existing power structures and conflicting interests, and being considered as extra work instead of an integral task with an inherent value in itself. By demonstrating some of the underlying causes of the challenging practice of TD, we reveal starting points for changes and provide recommendations that aim to set the base for a more reflexive and fruitful TD knowledge co-production. 相似文献
250.
Long-term effects of lead poisoning on bone mineralization in vultures exposed to ammunition sources
Gangoso L Alvarez-Lloret P Rodríguez-Navarro AA Mateo R Hiraldo F Donázar JA 《Environmental pollution (Barking, Essex : 1987)》2009,157(2):569-574
Long-lived species are particularly susceptible to bioaccumulation of lead in bone tissues. In this paper we gain insights into the sublethal effects of lead contamination on Egyptian vultures (Neophron percnopterus). Our approach was done on the comparison of two populations (Canary Islands and Iberian Peninsula) differing in exposures to the ingestion of lead ammunition. Blood lead levels were higher in the island population (Canary Islands range: 5.10-1780 μg L−1n = 137; Iberian Peninsula range: 5.60-217.30 μg L−1n = 32) showing clear seasonal trends, peaking during the hunting season. Moreover, males were more susceptible to lead accumulation than females. Bone lead concentration increased with age, reflecting a bioaccumulation effect. The bone composition was significatively altered by this contaminant: the mineralization degree decreased as lead concentration levels increased. These results demonstrate the existence of long-term effects of lead poisoning, which may be of importance in the declines of threatened populations of long-lived species exposed to this contaminant. 相似文献