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91.
Fernández-Llamazares Álvaro Garcia Raquel Amaral Díaz-Reviriego Isabel Cabeza Mar Pyhälä Aili Reyes-García Victoria 《Regional Environmental Change》2017,17(6):1673-1685
Regional Environmental Change - Existing climate data for Bolivian Amazonia rely on observations from a few sparse weather stations, interpolated on coarse-resolution grids. At the same time, the... 相似文献
92.
A. V. Krusche F. P. de Garvaiho J. M. de Moraes P. B. de Camargo M. V. R. Ballester S. Hornink L. A. Martinelli R. L. Victoria 《Journal of the American Water Resources Association》1997,33(5):1117-1123
ABSTRACT: The spatial and temporal variability of dissolved oxygen (DO), biochemical oxygen demand (BOD), nitrate concentration and total coliform (TC) were investigated at nine sampling stations distributed along the main rivers of the Piracicaba River Basin, a 12,400 km2 catchment located in São Paulo State, one of the most developed regions of Brazil. Spatially, a downstream impoverishment of water quality conditions was observed, as seen by the decrease of DO, and increase of BOD, nitrate, and TC. These changes were probably caused by accumulating downstream discharge of domestic and industrial sewage. Temporal evaluation of 18 years of data showed that DO decreased with time for the majority of the sampling stations, while BOD, nitrate, and TC increased. A law, approved at the end of 1991, proposed a new water tax for river water extraction for industrial and agricultural use. The amount of this tax is determined according to the water quality of the extracted water. Therefore, the evaluation of the water quality status in this basin is a first step to help resources managers to determine the values for this tax. 相似文献
93.
Some marine species have been shown to target foraging at particular hotspots of high prey abundance. However, we show here that in the year after a nesting season, female leatherback turtles (Dermochelys coriacea) in the Atlantic generally spend relatively little time in fixed hotspots, especially those with a surface signature revealed in satellite imagery, but rather tend to have a pattern of near continuous traveling. Associated with this traveling, distinct changes in dive behavior indicate that turtles constantly fine tune their foraging behavior and diel activity patterns in association with local conditions. Switches between nocturnal vs. diurnal activity are rare in the animal kingdom but may be essential for survival on a diet of gelatinous zooplankton where patches of high prey availability are rare. These results indicate that in their first year after nesting, leatherback turtles do not fit the general model of migration where responses to resources are suppressed during transit. However, their behavior may be different in their sabbatical years away from nesting beaches. Our results highlight the importance of whole-ocean fishing gear regulations to minimize turtle bycatch. 相似文献
94.
Goodwin V Jones-Hughes T Thompson-Coon J Boddy K Stein K 《Journal of Safety Research》2011,42(6):443-451
Problem and objective
The translation of the evidence-base for preventing falls among community-dwelling older people into practice has been limited. This study systematically reviewed and synthesised the effectiveness of methods to implement falls prevention programmes with this population.Methods
Articles published between 1980 and May 2010 that evaluated the effects of an implementation strategy. No design restrictions were imposed. A narrative synthesis was undertaken.Results
15 studies were identified. Interventions that involved the active training of healthcare professionals improved implementation. The evidence around changing the way people who fall are managed within primary care practices, and, layperson, peer or community delivered models was mixed.Impact on industry
Translating the evidence-base into practice involves changing the attitudes and behaviours of older people, healthcare professionals and organisations. However, there is a need for further evaluation on how this can be best achieved. 相似文献95.
Johannes M. M. Engels Hannes Dempewolf Victoria Henson-Apollonio 《Journal of Agricultural and Environmental Ethics》2011,24(2):107-126
Humans have always played a crucial role in the evolutionary dynamics of agricultural biodiversity and thus there is a strong
relationship between these resources and human cultures. These agricultural resources have long been treated as a global public
good, and constitute the livelihoods of millions of predominantly poor people. At the same time, agricultural biodiversity
is under serious threat in many parts of the world despite extensive conservation efforts. Ethical considerations regarding
the collecting, research, and use of agricultural biodiversity are currently topics of great concern. For example, easy access
to genetic resources for breeding purposes is important, but international agreements and legal frameworks are necessary to
ensure adequate recognition of the contributions of local communities and traditional farmers in creating and nurturing these
resources. Here, we assess ethical principles in the context of existing codes of conduct that are relevant for agro-biodiversity
researchers. We aim to create awareness among scientists and policy makers who are concerned with agro-biodiversity research
and its potential impact on local communities. We encourage a serious assessment of the ethical principles presented here
and hope to facilitate an integration of these principles into the reader’s personal ethical framework. Key ethical principles
considered here include the importance of obtaining prior informed consent, equity, and the inalienability of rights of local
communities and farmers. 相似文献
96.
Benkdad A Laissaoui A Tornero MV Benmansour M Chakir E Garrido IM Moreno JB 《Environmental monitoring and assessment》2011,182(1-4):317-324
Macroalgae species Codium sp, Bangia atropurpurea, Membranoptera alata, Plocamium cartilagineum, Dictyota dichotoma, Fucus spiralis and Stypocaulon scoparia were collected from seven stations along the north coast of Morocco. Samples were analysed to determine activities of naturally occurring radionuclides ((210)Pb, U isotopes and (40)K) and concentrations of metals (Zn, Fe, Co, Cu, Ni, Mn, Pb, Cd, As and Cr) using radiometric and ICP-OES techniques, respectively. Metal concentrations were within ranges reported in the scientific literature, and concentrations of bio-essential elements were in the order Mn>Fe> Zn>Cu in all samples. Brown algae had the highest concentrations of almost all metals, and concentrations decreased in the order brown>red>green algae. With respect to radionuclides, the red alga P. cartilagineum had the highest activities of (210)Pb, in most cases an order of magnitude higher than for the green alga Codium sp. (234)U and (238)U activities in all algae samples were in the range 0.96- 7.61 and 1.16-6.14 Bq/kg dry weight, respectively. Our analyses of radionuclide activities and metal concentrations in marine macroalgae showed large differences among taxa. These results provide insights into which algal species should be used for biomonitoring programmes. 相似文献
97.
Huang V Sakata JT Rhen T Coomber P Simmonds S Crews D 《Die Naturwissenschaften》2008,95(12):1137-1142
Kratochvil et al. (Naturwissenschaften 95:209–215, 2008) reported recently that in the leopard gecko (Eublepharis macularius) of the family Eublepharidae with temperature-dependent sex determination (TSD), clutches in which eggs were incubated at
the same temperature produce only same-sex siblings. Interpreting this result in light of studies of sex steroid hormone involvement
in sex determination, they suggested that maternally derived yolk steroid hormones could constrain sex-determining mechanisms
in TSD reptiles. We have worked extensively with this species and have routinely incubated clutches at constant temperatures.
To test the consistency of high frequency same-sex clutches across different incubation temperatures, we examined our records
of clutches at the University of Texas at Austin from 1992 to 2001. We observed that clutches in which eggs were incubated
at the same incubation temperature produced mixed-sex clutches as well as same-sex clutches. Furthermore, cases in which eggs
within a clutch were separated and incubated at different temperatures produced the expected number of mixed-sex clutches.
These results suggest that maternal influences on sex determination are secondary relative to incubation temperature effects. 相似文献
98.
Aleksandropoulou V Eleftheriadis K Diapouli E Torseth K Lazaridis M 《Journal of environmental monitoring : JEM》2012,14(1):266-278
The objective of this work was to study PM(10) and PM(2.5) concentration data available from monitoring stations in two large urban agglomerations in Greece and to estimate the emissions reduction required for compliance with the EU Air Quality Standards (AQS) for particulate matter. The cities studied are namely the Athens and Thessaloniki Metropolitan Areas (AMA and TMA, respectively). PM(10) concentrations during the period 2001-2010 have been evaluated for 15 air quality monitoring stations in the two urban areas. It was found that the concentrations of PM(10) during the period studied constantly exceeded the threshold values at the traffic and industrial stations in TMA and most of the traffic sites in AMA. Most of the occurrences of non-attainment to the daily AQSs were observed during the winter period at all stations (more pronounced for TMA stations). The reduction in current emission source strength to meet the air quality goal was calculated by the rollback equation using PM(10) day-averaged concentrations over the selected period at each station. Among the lognormal and Weibull distributions, the lognormal distribution was found to best fit the frequency distributions of PM(10) concentrations at the selected stations. The results showed that the minimum reduction required in order to meet the AQS in the AMA ranges from approximately 20 to 38% and up to 11% for traffic and background stations, respectively. Reductions in the range of 31% for traffic and 44% for industrial areas in TMA are also required. The same methodology was applied to PM(2.5) concentrations in the AMA and showed that emission reductions up to 31% are necessary in order to meet the 2020 EU AQS. Finally, continuous concentration data of organic (OC) and elementary carbon (EC) in PM(2.5) were used to study the possibility of achieving specific emission attenuation objectives in AMA. 相似文献
99.
Graft copolymers of starch and polyacrylamide (PAAm) were prepared using reactive extrusion in a corotating twin screw extruder.
The effect of cationic starch modification was examined using unmodified and cationic dent starch (≈23% amylose) and waxy
maize starch (≈2% amylose). For a fixed acrylamide/starch feed ratio, conversion, graft content, and grafting efficiency were
essentially unaffected by starch type or modification. Cationic starch graft copolymers generally had lower molecular weight
PAAm grafts compared to the unmodified starch, whereas amylose content had little or no significant effect. In addition, the
frequency of grafting was higher with cationic starch. These results indicate that cationic modification of starch enhances
formation of grafting sites, resulting in graft copolymers with more grafts of lower molecular compared to unmodified starch.
Cationic modification may therefore be a way to tailor the properties of starch–PAAm graft copolymers. 相似文献
100.
Erin Towler Victoria A. Saab Richard S. Sojda Katherine Dickinson Cindy L. Bruyère Karen R. Newlon 《Environmental management》2012,50(6):1152-1163
Given the projected threat that climate change poses to biodiversity, the need for proactive response efforts is clear. However, integrating uncertain climate change information into conservation planning is challenging, and more explicit guidance is needed. To this end, this article provides a specific example of how a risk-based approach can be used to incorporate a species’ response to climate into conservation decisions. This is shown by taking advantage of species’ response (i.e., impact) models that have been developed for a well-studied bird species of conservation concern. Specifically, we examine the current and potential impact of climate on nest survival of the Lewis’s Woodpecker (Melanerpes lewis) in two different habitats. To address climate uncertainty, climate scenarios are developed by manipulating historical weather observations to create ensembles (i.e., multiple sequences of daily weather) that reflect historical variability and potential climate change. These ensembles allow for a probabilistic evaluation of the risk posed to Lewis’s Woodpecker nest survival and are used in two demographic analyses. First, the relative value of each habitat is compared in terms of nest survival, and second, the likelihood of exceeding a critical population threshold is examined. By embedding the analyses in a risk framework, we show how management choices can be made to be commensurate with a defined level of acceptable risk. The results can be used to inform habitat prioritization and are discussed in the context of an economic framework for evaluating trade-offs between management alternatives. 相似文献