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221.
The roles of fermentative acidogenic bacteria and sulfate-reducing bacteria (SRB) in lactate degradation and sulfate reduction in a sulfidogenic bioreactor were investigated by traditional chemical monitoring and culture-independent methods. A continuously stirred tank reactor fed with synthetic wastewater containing lactate and SO(2-)(4) at 35 degrees C, 10h of hydraulic retention time was used. The results showed that sulfate removal efficiency reached 99%, and sulfide and acetate were the main end products after 20 d of operation. 16S rRNA gene based clone libraries and single-strand conformation polymorphism profiles demonstrated that the proportion of SRB increased from 16% to 95%, and that Desulfobulbus spp., Desulfovibrio spp., Pseudomonas spp. and Clostridium spp. formed a stable, dominant community structure. The decreasing COD/SO(2-)(4) ratio had little effect on the community pattern except that Pseudomonas spp. and Desulfobulbus spp. increased slightly. The addition of molybdate to the influent significantly changed the microbial community, sulfate removal efficiency and the pattern of end products. Clostridium spp., Bacteroides spp. and Ruminococcus spp. became the dominant community members. The main end products switched from acetate to ethanol and then to propionate with the oxidation-reduction potentials increasing from -420 to -290 mV. A lactate degradation pathway was deduced: lactate served as the electronic donor for Desulfovibrio spp., or was fermented by Clostridium spp. and Bacteroides spp. to produce propionate or ethanol, which were subsequently utilized by Desulfobulbus spp. and Desulfovibrio spp. The acidotrophic SRB oxidized part of the acetate finally. 相似文献
222.
Coastal deforestation in the Ayeyarwady Delta, Myanmar (formerly Burma) is addressed through the promotion of native-species
mangrove plantations on cleared land formerly sustaining natural mangrove forests. To date there are no attempts to determine
the optimal mangrove plantation strategy to maximize economic returns for private or communal plantation owners. We integrated
empirical biological and economic data to suggest optimal mangrove plantation strategies in the region. We censused 4-yr oldAvicennia officinalis mangrove plantations in two townships to calculate survival and growth rates of mangroves planted using different techniques
across an inundation gradient. We used the calculated rates to forecast the production of fuelwood, poles and posts at 10,
13 and 15 yr after establishment. We calculated the compound rate of growth for the three commodities over a 7-yr period,
and then forecast commodity price for the same harvestintervals. Integration of those parameters in our model led us to conclude
that both profit and the internal rate of return would be greatest for plantations of seedlings raised in polyethylene bags
as opposed to bare-root or direct propagule planting. Therefore, the use of potted seedlings should be promoted, despite higher
initial costs. The optimal rotation period varies according to ground level and planting technique. Optimizing economic returns
for coastal plantations does not necessarily require a sacrifice of ecological benefits.
Due to a discrepancy between official conversion quotes and local real value no conversion estimate in USD is given. 相似文献
223.
Coastal deforestation in the Ayeyarwady Delta, Myanmar (formerly Burma) is addressed through the promotion of native-species
mangrove plantations on cleared land formerly sustaining natural mangrove forests. To date there are no attempts to determine
the optimal mangrove plantation strategy to maximize economic returns for private or communal plantation owners. We integrated
empirical biological and economic data to suggest optimal mangrove plantation strategies in the region. We censused 4-yr oldAvicennia officinalis mangrove plantations in two townships to calculate survival and growth rates of mangroves planted using different techniques
across an inundation gradient. We used the calculated rates to forecast the production of fuelwood, poles and posts at 10,
13 and 15 yr after establishment. We calculated the compound rate of growth for the three commodities over a 7-yr period,
and then forecast commodity price for the same harvest intervals. Integration of those parameters in our model led us to conclude
that both profit and the internal rate of return would be greatest for plantations of seedlings raised in polyethylene bags
as opposed to bare-root or direct propagule planting. Therefore, the use of potted seedlings should be promoted, despite higher
initial costs. The optimal rotation period varies according to ground level and planting technique. Optimizing economic returns
for coastal plantations does not necessarily require a sacrifice of ecological benefits.
Due to a discrepancy between official conversion quotes and local real value no conversion estimate in USD is given. 相似文献
224.
The article considers the impact of introducing government co-management policy in the form of Joint Forest Management (JFM) in an area with a five-decade-old self-organized community forest management system in Orissa, India. We ask a question that appears not to have been previously examined: What happens when JFM replaces an already existing community forest management arrangement? Our comparison of the JFM arrangement with the self-organized community forest management regime (pre- and post-2002 in a selected village) provides three conclusions: (1) The level of villager participation in forest management has declined, along with the erosion of the bundle of common rights held by them; (2) multiple institutional linkages between the village and outside agencies, and reciprocal relations with neighboring villages have been abandoned in favor of a close relationship with the Forestry Department; and (3) the administration of the forestry resource has become politicized. We conclude that the “one-size-fits-all” approach of the JFM, with its pre-packaged objectives and its narrow scope of forest management, is likely to limit experimentation, learning, and institutional innovation that characterizes community forest management. 相似文献
225.
We investigated the acute impact of trinitrotoluene (TNT) contamination of soil on the aerobic bacterial community composition and function. The contamination of the environment with explosive residues presents a serious problem at sites across the world, with the highly toxic compound TNT being the most widespread explosive contaminant. We investigated the acute impact of trinitrotoluene (TNT) contamination of soil on the aerobic bacterial community composition and function. Soil microcosms were amended with a range of concentrations of TNT for 30 days. A polyphasic approach encompassing culture-independent molecular analysis by DGGE, community-level physiological profiling (CLPP) and cell enumeration revealed that the amendment of soils with TNT resulted in a shift from slower growing k-strategists towards faster growing r-strategists. Pseudomonads became prevalent at high concentrations of TNT. Pollution induced community tolerance (PICT) was observed as TNT concentrations increased. Chemical analyses revealed that TNT was reduced to its amino derivatives, products of reductive microbial transformation. The transformation to amino derivatives decreased at high concentrations of TNT, indicative of inhibition of microbial TNT transformation. 相似文献
226.
Fukunaga A Anderson MJ Webster-Brown JG 《Environmental pollution (Barking, Essex : 1987)》2011,159(1):116-124
Elevated levels of copper and zinc in sediment have been shown to adversely affect estuarine infauna. We investigated the additivity of the combined effects of copper and zinc on infaunal recolonisation through a manipulative field experiment in Orewa estuary, New Zealand, using defaunated sediment discs treated with these metals. The nature of their combined effects varied among infaunal taxa and the particular variables being examined. Additive effects were detected for species richness, for the mean log abundances of the polychaetes Prionospio sp. and Scoloplos cylindrifer and for the multivariate response of the community as a whole. Antagonistic effects were detected for the mean log abundances of total infauna and the polychaete Heteromastus sp. Characterising the potentially interactive nature of the combined effects of multiple heavy metals is essential in order to build predictive models of future environmental impacts of metal accumulation in estuarine sediments. 相似文献
227.
B. Sen Gupta S. Chatterjee H. Kauffman W. DeGroot 《Environmental pollution (Barking, Essex : 1987)》2009,157(12):3351-3353
This report describes a simple chemical free method that was successfully used by a team of European and Indian scientists (www.qub.ac.uk/tipot) to remove arsenic (As) from groundwater in a village in West Bengal, India. Six such plants are now in operation and are being used to supply water to the local population (www.insituarsenic.org). The study was conducted in Kasimpore, a village in North 24 Parganas District, approximately 25 km from Kolkata. In all cases, total As in treated water was less than the WHO guideline value of 10 μg L−1. The plant produces no sludge and the operation cost is 1.0 US$ per day for producing 2000 L of potable water. 相似文献
228.
This research presents the results of a qualitative study of a small sample of older adults (n = 25), age 55+ who have recently moved to an area that is rapidly changing from a tourist community into a retirement community. The study has two main research objectives: (a) to use Oswald and Wahl's heuristic meaning of home framework to explore the relationships between older adults and their homes and communities, integrating theories from environmental psychology, environmental gerontology and human geography, and (b) to discuss the empirical findings focussing on the core concepts of meaning of home and sense of belonging for new retirees to an area. Findings: For new retirees, there exists a zone between the home and community, that can be viewed as a geographic space comprised of overlapping and interwoven personal, social and physical domains. This zone between the physical house and the surrounding community can be construed as having certain elastic qualities and permeable boundaries that blur the distinctions between home and community. A focus on the micro-environment of the home dwelling and the macro-environment of the neighbourhood and community then appears relevant for understanding place attachment for these persons. This idea of the ‘home beyond the house’ – is one of the most important contributions of this research. Our results view the heuristic framework of Oswald and Wahl as a valuable tool for building understanding about the meaning of home for older adults by drawing attention to the domains themselves, and more importantly, to the interrelationships between them. Consequently, for younger in-migrants, the boundary between home and community blurs into one larger, symbolic entity experienced as ‘home’. 相似文献
229.
This article describes a template for implementing an integrated community sustainability plan. The template emphasizes community
engagement and outlines the components of a basic framework for integrating ecological, social and economic dynamics into
a community plan. The framework is a series of steps that support a sustainable community development process. While it reflects
the Canadian experience, the tools and techniques have applied value for a range of environmental planning contexts around
the world. The research is case study based and draws from a diverse range of communities representing many types of infrastructure,
demographics and ecological and geographical contexts. A critical path for moving local governments to sustainable community
development is the creation and implementation of integrated planning approaches. To be effective and to be implemented, a
requisite shift to sustainability requires active community engagement processes, political will, and a commitment to political
and administrative accountability, and measurement. 相似文献
230.
A Typology of Collaboration Efforts in Environmental Management 总被引:4,自引:1,他引:3
Margerum RD 《Environmental management》2008,41(4):487-500
Collaboration involves stakeholders and the public in a process of consensus building to address some of the most difficult
environmental management problems facing society today. Collaborative groups vary widely, ranging from small watershed councils
to regional ecosystem collaboratives to groups addressing large-scale policy issues. While these collaboratives all match
the common principles of collaboration, a closer examination reveals many differences. Using institutional theories about
levels of decision making provides a way of classifying collaboratives along a spectrum from action level to organizational
level to policy level. This typology is applied to thirty-six collaboration case studies in Australia and the United States
that were investigated over a series of years through interviews, observation, document analysis, and surveys. The application
reveals different tendencies among the case types in terms of population, size, problem significance, institutional setting,
and focus of activities. The typology also reveals functional differences in the types of stakeholders involved, the management
arrangements for implementation, and the approaches to implementing change. This typology can help practitioners better understand
the challenges and appropriate types of collaborations for different settings. It helps highlight differences in the role
of government and decentralization of power. It distinguishes the different theoretical foundations for different types of
collaboratives. Finally, it elucidates the different evaluation approaches for different types of collaboratives. 相似文献