全文获取类型
收费全文 | 501篇 |
免费 | 12篇 |
国内免费 | 6篇 |
专业分类
安全科学 | 33篇 |
废物处理 | 11篇 |
环保管理 | 67篇 |
综合类 | 59篇 |
基础理论 | 104篇 |
污染及防治 | 150篇 |
评价与监测 | 62篇 |
社会与环境 | 26篇 |
灾害及防治 | 7篇 |
出版年
2023年 | 8篇 |
2022年 | 20篇 |
2021年 | 13篇 |
2020年 | 8篇 |
2019年 | 12篇 |
2018年 | 19篇 |
2017年 | 21篇 |
2016年 | 25篇 |
2015年 | 18篇 |
2014年 | 10篇 |
2013年 | 66篇 |
2012年 | 22篇 |
2011年 | 33篇 |
2010年 | 31篇 |
2009年 | 17篇 |
2008年 | 16篇 |
2007年 | 20篇 |
2006年 | 24篇 |
2005年 | 16篇 |
2004年 | 6篇 |
2003年 | 10篇 |
2002年 | 11篇 |
2001年 | 2篇 |
2000年 | 3篇 |
1999年 | 4篇 |
1998年 | 7篇 |
1997年 | 5篇 |
1996年 | 5篇 |
1994年 | 3篇 |
1993年 | 8篇 |
1992年 | 2篇 |
1991年 | 5篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 5篇 |
1984年 | 4篇 |
1983年 | 4篇 |
1982年 | 4篇 |
1981年 | 7篇 |
1980年 | 3篇 |
1977年 | 2篇 |
1974年 | 1篇 |
1972年 | 3篇 |
1968年 | 1篇 |
1967年 | 1篇 |
1965年 | 2篇 |
1958年 | 1篇 |
1957年 | 1篇 |
排序方式: 共有519条查询结果,搜索用时 15 毫秒
371.
Adaptation investments: a resource allocation framework 总被引:1,自引:0,他引:1
Rhona Barr Samuel Fankhauser Kirk Hamilton 《Mitigation and Adaptation Strategies for Global Change》2010,15(8):843-858
Additional finance for adaptation is an important element of the emerging international climate change framework. This paper
discusses how adaptation funding may be allocated among developing countries in a transparent, efficient and equitable way.
We propose an approach based on three criteria: the climate change impacts experienced in a country, a country’s adaptive
capacity and its implementation capacity. Physical impact and adaptive capacity together determine a country’s vulnerability
to climate change. It seems both efficient and fair that countries which are more vulnerable should have a stronger claim
on adaptation resources. The third dimension, implementation capacity, introduces a measure of adaptation effectiveness. Rough
indicators are proposed for each of the three dimensions. The results are indicative only, but they suggest a strong focus
of initial adaptation funding on Africa. African countries are highly vulnerability in part because of the severity of expected
impacts, but also because of their very low adaptive capacity. However, their implementation capacity is also limited, suggesting
a need for technical assistance in project implementation. 相似文献
372.
The city is a growing centre of humanitarian concern. Yet, aid agencies, governments and donors are only beginning to comprehend the scale and, importantly, the complexity of the humanitarian challenge in urban areas. Using the case study of the Kathmandu Valley, Nepal, this paper examines the analytical utility of recent research on complex urban systems in strengthening scholarly understanding of urban disaster risk management, and outlines its operational relevance to disaster preparedness. Drawing on a literature review and 26 interviews with actors from across the Government of Nepal, the International Red Cross and Red Crescent Movement, non‐governmental organisations, United Nations agencies, and at‐risk communities, the study argues that complexity can be seen as a defining feature of urban systems and the risks that confront them. To manage risk in these systems effectively, preparedness efforts must be based on adaptive and agile approaches, incorporating the use of network analysis, partnerships, and new technologies. 相似文献
373.
Urbanization can have profound effects on the plant communities persisting in remnant habitats. That process can be explored by examining patterns of nestedness. Species composition for a set of communities exhibits a nested pattern if species present in progressively richer assemblages form a series of subsets. Nestedness can form as a result of the dynamic processes of extinction or colonization. It can also reflect a nested distribution of habitats among the sites or the differential abundance properties of species through passive sampling. This study investigated whether Sonoran Desert woody vegetation in remnant islands within metropolitan Phoenix is nested and explored which mechanisms are responsible for the pattern. It also examined whether vegetation is nested in similar habitat types across islands, and how species abundance relates to the nested pattern and hypothesized mechanisms. All data sets were significantly nested, indicating a nested pattern at the island and habitat levels. Community-level analyses did not indicate a primary mechanism leading to the nested pattern. Among species with abundances correlated with the nested rank-order of sites, abundance properties were significantly related to different variables. This suggests that individual taxa respond to divergent ecological mechanisms, leading to nestedness. Thus, nestedness in plant communities can result from a complex set of contributors and may not be attributable to a single factor. 相似文献
374.
Model of coral population response to accelerated bleaching and mass mortality in a changing climate
We model coral community response to bleaching and mass mortality events which are predicted to increase in frequency with climate change. The model was parameterized for the Arabian/Persian Gulf, but is generally applicable. We assume three species groups (Acropora, faviids, and Porites) in two life-stages each where the juveniles are in competition but the adults can enter a size-refuge in which they cannot be competitively displaced. An aggressive group (Acropora species) dominates at equilibrium, which is not reached due to mass mortality events that primarily disadvantage this group (compensatory mortality, >90% versus 25% in faviids and Porites) roughly every 15 years. Population parameters (N individuals, carrying capacity) were calculated from satellite imagery and in situ transects, vital rates (fecundity, mortality, and survival) were derived from the model, field observations, and literature. It is shown that populations and unaltered community structure can persist despite repeated 90% mortality, given sufficiently high fecundity of the remaining population or import from connected populations. The frequency of disturbance determines the dominant group—in low frequency Acropora, in high frequency Porites. This is congruent with field observations. The model of an isolated population was more sensitive to parameter changes than that of connected populations. Highest sensitivity was to mortality rate and recruitment rate. Community composition was sensitive to spacing of disturbances and level of catastrophic mortality. Decreased mortality led to Acropora dominance, increased mortality led to Acropora extinction. In nature, closely spaced disturbances have severely disadvantaged Acropora populations over the last decade. Unless a longer (>10 years) disturbance-free interval can be maintained, a permanent shift away from Acropora dominance will be observed. A mortality rate of 99% in Acropora, as observed in 1996, is not sustainable if repetitive and neither is a disturbance frequency <15 years—each leading to population collapse. This shows that the severity and/or the spacing of the 1996–1998–2002 disturbances were unusual in frequency and duration. 相似文献
375.
Microbial symbionts can affect plant nutrition, defensive chemistry, and biodiversity. Here we test the hypothesis that symbionts alter the speed and direction of plant succession in communities that are shifting from grasslands to forests. A widespread C3 grass introduced to the United States, Lolium arundinaceum (tall fescue), hosts a fungal endophyte that is toxic to herbivores. In replicated experimental grasslands, the presence of the endophyte in tall fescue reduced tree abundance and size, altered tree composition, and slowed plant species turnover. In addition, consumption of tree seedlings by voles (Microtus spp.) was 65% higher in plots with the endophyte at the one grassland site where these data were collected. Despite its negligible contribution to community biomass, a microbial symbiont suppressed tree establishment, posing an important constraint on the natural transition from grasslands to forests. 相似文献
376.
Igor W. K. Ouédraogo Erol Pehlivan Hien T. Tran Samuel Paré Yvonne L. Bonzi-Coulibaly Dieter Zachmann 《毒物与环境化学》2016,98(7):736-747
Arsenic (V) adsorption on manganese oxide coated rice wastes was investigated in this study. The modified adsorbents were characterized by Fourier-transform infrared spectroscopy, scanning electron microscopy, and pH measurements to determine the point of zero charge. Batch adsorption equilibrium experiments were conducted to study the effects of pH, contact time, and initial concentration on arsenic removal efficiency. The adsorption capacity of rice waste was significantly improved after modification with permanganate. The Langmuir isotherm model fitted the equilibrium data better than the Freundlich model which confirms surface homogeneity of the adsorbent. Maxima adsorption capacities are determined as 10 and 12 mg/g at pH 3 for manganese oxide coated rice husk and straw, respectively. The adsorption energy indicates that the adsorption process may be dominated by chemisorption. Pseudo-second-order rate equation described the kinetics sorption of arsenic with good correlation coefficients, better than a pseudo-first-order equation. Manganese oxide coated rice husk and straw appear to be promising low cost adsorbents for removing arsenic from water. 相似文献
377.
Given the common use of self‐ratings and other‐ratings (e.g., supervisor or coworker) of organizational citizenship behavior (OCB), the purpose of this meta‐analysis was to evaluate the extent to which these rating sources provide comparable information. The current study's results provided three important lines of evidence supporting the use and construct‐related validity of self‐rated OCB. The meta‐analysis of mean differences demonstrated that the mean difference in OCB ratings is actually quite small between self‐ and other‐raters. Importantly, the difference between self‐ and other‐raters was influenced by neither the response scale (i.e., agreement vs. frequency) nor the use of antithetical/reverse‐worded items on OCB scales. The meta‐analysis of correlations showed that self‐ and other‐ratings are moderately correlated but that self–other convergence is higher when antithetical items are not used and when agreement response scales are used. In addition, self‐ratings and supervisor‐ratings showed significantly more convergence than self‐ratings and coworker‐ratings. Finally, an evaluation of self‐rated and other‐rated OCB nomological networks showed that although self‐rated and other‐rated OCBs have similar patterns of relationships with common correlates, other‐rated OCB generally contributed negligible incremental variance to correlates and only contributed appreciable incremental variance to other‐rated behavioral variables (e.g., task performance and counterproductive work behavior). Implications and future research directions are discussed, particularly regarding the need to establish a nomological network for other‐rated OCB. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
378.
Matagi SV 《Environmental monitoring and assessment》2002,77(2):121-138
Kampala, the capital city of Uganda is the administrative, political, commercial, industrial, educational and cultural centre of Uganda. The city has an area of 190 km2 and is located 8 km north of Lake Victoria (the second largest fresh water lake in the world) and approximately 42 km north of the equator. The population varies from about 1.2 million during the day to perhaps 0.9 million at night. The anthropogenic activityof this population far exceeds the infrastructure capacity of the city, leading to the deterioration of the urban environment. This article highlights the major sources of environmental degradation and pollution in the city, which include solid waste,abattoir waste, sewage, sanitation, drainage, industrial pollution, traffic pollution, atmospheric pollution, urban agriculture, rapid urbanisation and water hyacinth. 相似文献
379.
Land application of carbonatic lake-dredged materials: effects on soil quality and forage productivity 总被引:1,自引:0,他引:1
The ability to reuse carbonatic lake-dredged materials (CLDM) for agricultural purposes is important because it reduces offshore disposal and provides an alternative to disposal of the materials in landfills that are already overtaxed. A four-year (2001 to 2005) study on land application of CLDM as an option for disposal was conducted on a beef cattle pasture in south central Florida. The objectives of this study were (i) to assess CLDM as a soil amendment to improve quality of sandy soils in most subtropical beef cattle pastures and (ii) to determine the effect of CLDM on productivity and nutritive values of bahiagrass (BG, Paspalum notatum Flügge) in subtropical beef cattle pasture. The five treatment combinations arranged in randomized complete block design were represented by plots with different ratios (R) of natural soil (NS) to CLDM: R1 (1000 g kg(-1):0 g kg(-1)); R2 (750 g kg(-1):250 g kg(-1)); R3 (500 g kg(-1):500 g kg(-1)); R4 (250 g kg(-1):750 g kg(-1)); and R5 (0 g kg(-1):1000 g kg(-1)). Addition of CLDM had significant (p < or = 0.001) effects on soil quality and favorable influence on forage establishment and nutritive values. Compared with the control plots (0 g kg(-1)), the soils in plots amended with CLDM exhibited (i) lower penetration resistance, (ii) an increase in soil pH and exchangeable cations (Ca and Mg), and (iii) decrease in the levels of soil trace metals (Mn, Cu, Fe, Zn, and Si). Results disclosed consistently and significantly (p < or = 0.001) higher BG biomass production (forage yield = -106.3x(2) + 1015.8x - 39.2; R(2) = 0.99**) and crude protein content (CP = 1.24x + 6.48; R(2) = 0.94**) from plots amended with CLDM than those of BG planted on plots with no CLDM treatment. 相似文献
380.
Identifying Potential Conflict Associated with Oil and Gas Exploration in Texas State Coastal Waters: A Multicriteria Spatial Analysis 总被引:1,自引:0,他引:1
Brody SD Grover H Bernhardt S Tang Z Whitaker B Spence C 《Environmental management》2006,38(4):597-617
Recent interest in expanding offshore oil production within waters of the United States has been met with opposition by groups
concerned with recreational, environmental, and aesthetic values associated with the coastal zone. Although the proposition
of new oil platforms off the coast has generated conflict over how coastal resources should be utilized, little research has
been conducted on where these user conflicts might be most intense and which sites might be most suitable for locating oil
production facilities in light of the multiple, and often times, competing interests. In this article, we develop a multiple-criteria
spatial decision support tool that identifies the potential degree of conflict associated with oil and gas production activities
for existing lease tracts in the coastal margin of Texas. We use geographic information systems to measure and map a range
of potentially competing representative values impacted by establishing energy extraction infrastructure and then spatially
identify which leased tracts are the least contentious sites for oil and gas production in Texas state waters. Visual and
statistical results indicate that oil and gas lease blocks within the study area vary in their potential to generate conflict
among multiple stakeholders. 相似文献