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41.
This article examines and discusses problems faced by proposals to increase participation by members of the public in the public debate process related to environmental policies. The analysis is based on an examination of the processes followed to develop several public meetings, which were ostensibly aimed at democratizing the process of implementing hydroelectric installations in the Madeira River in the Brazilian Amazon at the beginning of the twenty‐first century. The analysis concluded that the invitation to the public to participate in discussions regarding the construction of the dams was a mere formality. Not only did members of the public not have access to information that could have helped them understand the real social and environmental impacts of this large‐scale economic development project, but the public was restricted from interfering in its construction. As a consequence, the region is today dealing with a number of difficulties which could have been avoided if the voice of the community had been heard in the public meetings.  相似文献   
42.
Römbke J  Moser T 《Chemosphere》2002,46(7):1117-1140
In this paper the experiences concerning the organisation and results of the enchytraeid reproduction test (ERT) ringtest are summarised (for details see J. R?mbke, T. Moser, Organisation and Performance of an International Ringtest for the Validation of the Enchytraeid Reproduction Test, vols. I and II. UBA-Texte 4/99, 1999, 150, 223 pp). The performance of this ringtest was in line with requirements published by OECD. It was sponsored by the German Federal Environmental Agency (Umweltbundesamt; UBA, Berlin). The UBA was also actively engaged (together with the European Chemicals Bureau, Ispra) in a scientific task force, which consisted of seven scientists experienced in terrestrial ecology and ecotoxicology. 29 institutions (mainly from universities and contract research laboratories) from 15 countries of Europe and North America participated actively in the ringtest. The co-ordinating laboratory centrally distributed the test chemicals, guidance papers and test organisms to all participants. In addition, several training courses were organised. Most participants performed two tests with the fungicide Carbendazim and two with 4-nitrophenol. For each chemical, one test was designed according to an ECx approach and the other according to an NOEC approach. Several aspects of the test protocol were modified based on the experiences gained during the ringtest. A major aspect of the project was the detailed statistical evaluation of the test results (for details see A. Weyers, J. R?mbke, T. Moser, T. Ratte, Results of and statistical implications from the enchytraeid reproduction ringtest, 2001, submitted), leading to recommendations for an optimised ecotoxicological test design. A total of 92 tests were performed according to the protocol which is among the highest number ever performed in a ringtest. About 72% met the validity criteria (control mortality < 20%, > 25 juveniles per 10 adults). The effects of the two test chemicals on enchytraeid reproduction were in the range expected from data in the literature on oligochaete toxicity. However, statistical evaluation of the data was sometimes difficult as a result of the high variability in the number of juveniles. This variability was caused by several reasons, including hormesis effects or lack of experience of some participants. Comparison of the data from the NOEC and ECx approaches pointed to a clear advantage in favour of the latter. In most cases EC10 values were lower than the NOEC values determined in the same test. For details see A. Weyers et al. (loc. cit.). Reproducibility of the test data and practicability of the ERT ringtest were of the same order of magnitude as other ringtests recently performed. As a result of the ringtest, the ERT draft guideline was significantly improved. The new version is currently being standardised by OECD, ISO and ASTM.  相似文献   
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In this investigation different bioassays were used to detect the physiological and genotoxic effects of water samples of mining lakes. Especially bioassays with higher plants were used like the duckweed bioassay with Lemna minor, the cress bioassay with Lepidium sativum, the Tradescantia‐micronucleus bioassay and the Arabidopsis bioassay. In addition the algae‐motility bioassay with Euglena gracilis were used. All these bioassays were found to be suitable to investigate mining lake samples of extreme acidic character. Four mining lakes (ML 107, ML 111, ML 117, ML F) were selected. They show equally low pH‐values, but differ in size, age, hydro‐chemical and biological state. The results demonstrated that it is possible to differentiate the mining lakes based on the results of bioassays. Samples of ML 107 and 111 showed significant physiological and genotoxic effects. Water samples of both lakes caused severe damages and decreased growth at the same dilution level in all plant bioassays. ML F causes different effects on bioassays. The highest negative effect was observed on root development of L. sativum. ML 117 did not show any effects on duckweed, algae, Tradescantia or Arabidopsis bioassays. There was only a slight effect on the root development in the cress bioassay.  相似文献   
45.
Acrylamide (AMD), a neurotoxin and suspected carcinogen, is present at concentrations of up to 0.05% in linear anionic polyacrylamide, which is under evaluation as a temporary sealant in unlined irrigation canal systems across the United States. We examined the microbially mediated degradation of AMD and diversity of AMD-degrading microbial physiotypes in the Rocky Ford Highline Canal, Colorado to better constrain the potential fate ofAMD in a canal environment. Microorganisms able to use AMD (500 mg L(-1)) as a sole nitrogen source were relatively abundant (2.3 x 10(3) to 9.4 x 10(3) cells mL(-1) in water and 4.2 x 10(3) to 2.3 x 10(5) cells g(-1) in sediment). Only sediment samples contained microorganisms able to use AMD as a sole carbon source. Acrylamide (up to 100 mg L(-1)) was efficiently removed from amended canal water and sediment slurries under aerobic conditions, but no AMD degradation was observed in abiotic controls. Anaerobic degradation of AMD by nitrate-, sulfate-, and iron-reducing microorganisms was also tested, with nitrate reducers affecting the highest amounts of AMD removal (70.3-85%) after 60 d. All representatives (n=15) from a collection of 256 AMD-degrading microbial isolates from Rocky Ford Highline Canal were closely related to well characterized environmental bacteria capable of facultative nitrate respiration. Our results demonstrate that natural microbial populations within this canal are capable of AMD degradation under aerobic and anaerobic conditions and that this degradation is performed by naturally abundant bacteria likely to be present in other freshwater irrigation canals or similar lotic habitats.  相似文献   
46.
This study explores potential adaptation approaches in planning and management that the United States Forest Service might adopt to help achieve its goals and objectives in the face of climate change. Availability of information, vulnerability of ecological and socio-economic systems, and uncertainties associated with climate change, as well as the interacting non-climatic changes, influence selection of the adaptation approach. Resource assessments are opportunities to develop strategic information that could be used to identify and link adaptation strategies across planning levels. Within a National Forest, planning must incorporate the opportunity to identify vulnerabilities to climate change as well as incorporate approaches that allow management adjustments as the effects of climate change become apparent. The nature of environmental variability, the inevitability of novelty and surprise, and the range of management objectives and situations across the National Forest System implies that no single approach will fit all situations. A toolbox of management options would include practices focused on forestalling climate change effects by building resistance and resilience into current ecosystems, and on managing for change by enabling plants, animals, and ecosystems to adapt to climate change. Better and more widespread implementation of already known practices that reduce the impact of existing stressors represents an important “no regrets” strategy. These management opportunities will require agency consideration of its adaptive capacity, and ways to overcome potential barriers to these adaptation options.  相似文献   
47.
In streams and creeks, the aquatic flora is exposed to fluctuating concentrations of herbicides during and following their application. Peak concentrations of herbicides, like the chloroacetanilide S-metolachlor, are usually detected following rain events. In this study, we assessed the effect of S-metolachlor pulse exposure on the algae Scenedesmus vacuolatus. We measured the time-dependency of effects during exposure on algae population and identified the algae development stage most sensitive to S-metolachlor. Furthermore, we assessed the time-to-recovery of the algae following exposure. A 6h pulse exposure at 598mugl(-1) was sufficient to inhibit cell reproduction by 50%. However, the exposure period had to coincide with the cell development stage specifically inhibited by S-metolachlor, which is the end of the cell growth phase. In algae populations composed of cells at all development stages, we initially observed an increase in the size of some algal cells, ultimately leading to an inhibition of the growth rate. In these experimental conditions, effects were observed after 18h of exposure and greatly increased with time. The recovery of algae following exposure to strongly inhibiting S-metolachlor concentrations was delayed and only occurred after 29h. These findings suggest that peak exposure to S-metolachlor may affect the growth of sensitive alga in surface waters, considering that the effects extend beyond the period of exposure.  相似文献   
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49.
Megacities in low- and middle-income countries face unique threats from climate change as vulnerable populations and infrastructure are concentrated in high-risk areas. This paper develops a theoretical framework to characterize adaptation readiness in Global South cities and applies the framework to Dhaka, Bangladesh, a city with acute exposure and projected impacts from flooding and extreme heat. To gather case evidence from Dhaka we draw upon interviews with national and municipal government officials and a review of planning documents and peer-reviewed literature. We find: (1) national-level plans propose a number of adaptation strategies, but urban concerns compete with priorities such as protection of coastal assets and agricultural production; (2) municipal plans focus on identifying vulnerability and impacts rather than adaptation strategies; (3) interviewees suggest that lack of coordination among local government (LG) organizations and lack of transparency act as barriers for municipal adaptation planning, with national plans driving policy where LGs have limited human and financial resources; and (4) we found limited evidence that national urban adaptation directives trickle down to municipal government. The framework developed offers a systematic and standardized means to assess and monitor the status of adaptation planning in Global South cities, and identify adaptation constraints and opportunities.  相似文献   
50.
Scientific evidence accumulating over the past decade documents that climate change impacts are already being experienced in the US Northeast. Policy-makers and resource managers must now prepare for the impacts from climate change and support implementing such plans on the ground. In this paper we argue that climate change challenges the region to maintain its economic viability, but also holds some opportunities that may enhance economic development, human well-being, and social justice. To face these challenges and seize these opportunities effectively we must better understand adaptation capacities, opportunities and constraints, the social processes of adaptation, approaches for engaging critical players and the broader public in informed debate, decision-making, and conscious interventions in the adaptation process. This paper offers a preliminary qualitative assessment, in which we emphasize the need for (1) assessing the feasibility and side effects of technological adaptation options, (2) increasing available resources and improving equitable access to them, (3) increasing institutional flexibility, fit, cooperation and decision-making authority, (4) using and enhancing human and social capital, (5) improving access to insurance and other risk-spreading mechanisms, and (6) linking scientific information more effectively to decision-makers while engaging the public. Throughout, we explore these issues through illustrative sectoral examples. We conclude with a number of principles that may guide the preparation of future adaptation plans for the Northeast.  相似文献   
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