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51.
Gillian M. Raab Duncan P. H. Laxen Niall Anderson Steve Davis Michael Heaps Mary Fulton 《Environmental geochemistry and health》1993,15(4):191-200
The water lead concentrations measured in the homes of children who were part of the Edinburgh Lead study are related to the characteristics of the water supply and the household plumbing. At the time of the study one of the City of Edinburgh's two water supplies was lime treated to reduce plumbosolvency but in the second supply this treatment had not yet become effective. This allows us to estimate the extent to which this type of water treatment reduces water lead concentrations, in houses with lead plumbing, to comply with existing and proposed limits for lead in water. The kitchen cold water was supplied from a lead storage tank in 69 (15%) of the houses. These houses had the highest lead concentrations and water treTo whom correrspondence should be addressed. 相似文献
52.
R. Allen Brooks Martha S. Nizinski Steve W. Ross Kenneth J. Sulak 《Marine Biology》2007,152(2):307-314
The occurrence and relative abundance of tissue (arm) regeneration in the ophiuroid, Ophiacantha bidentata (Retzius), was examined in individuals collected primarily among colonies of the deep-water coral Lophelia pertusa off the southeastern United States. Seven deep-water coral sites (384–756 m), located between Cape Lookout, NC, and Cape
Canaveral, FL, were sampled in June 2004 using a manned submersible. The presence of regenerative tissue was evaluated by
visual inspection of each individual ophiuroid, and the proportion of regenerating arms per individual was examined relative
to size of individual, geographic location, and depth of collection. Ophiacantha bidentata, the dominant brittle star collected, commonly displayed signs of sublethal injury with over 60% of individuals displaying
some evidence of regeneration. These levels of regeneration rival those reported for shallow-water ophiuroids. Larger individuals
(>6.5 mm disc size) had a higher incidence of regeneration than smaller individuals. Size of individual and percent of regeneration
were negatively correlated with depth. Although O. bidentata was significantly less abundant in southern versus northern sites, ophiuroid abundance did not appear to be influenced by
amount or density of coral substratum. Presence of dense aggregations of O. bidentata indicates that they are an important component of the invertebrate assemblage associated with deep-water coral habitat especially
in the northern part of the study area. Assuming that observed frequencies of injury and subsequent regeneration represent
predation events then dense ophiuroid aggregations in deep-water coral habitats represent an important renewable trophic resource
within these communities. 相似文献
53.
Steve Holehouse 《生态毒理学报》1999,21(2)
1994年7月,环境部长代表新西兰政府宣布了要实施的一揽子措施,以确保该国能兑现它对它在1993年批准的<气候变化框架公约>(FCCC)的承诺.与钢铁制造等能源密集型工业特别有关的是开展关于CO2削减的志愿协议的建议.1995年2月,公布了建立与报道志愿协议的技术指导准则.这些是一个政府牵头的工作组的结果,该组包括工业界和部门代表以及能效与节能局及其它政府部委的工作人员.1995年9月,BHP新西兰钢材公司总经理和8家其它公司的首席执行官以及代表新西兰主要工业部门的行业团体,与能源部签署了它们的志愿协议.BHP新西兰钢材公司的协议代表一种要采取行动来限制其CO2排放的高层次公开与志愿承诺. 相似文献
54.
55.
Koala Conservation Policy Process: Appraisal and Recommendations 总被引:1,自引:0,他引:1
Tim W. Clark Nicole Mazur † Steven J. Cork ‡ Steve Dovers § and Ronnie Harding 《Conservation biology》2000,14(3):681-690
56.
57.
Robert A. Rose Dirck Byler J. Ron Eastman Erica Fleishman Gary Geller Scott Goetz Liane Guild Healy Hamilton Matt Hansen Rachel Headley Jennifer Hewson Ned Horning Beth A. Kaplin Nadine Laporte Allison Leidner Peter Leimgruber Jeffrey Morisette John Musinsky Lilian Pintea Ana Prados Volker C. Radeloff Mary Rowen Sassan Saatchi Steve Schill Karyn Tabor Woody Turner Anthony Vodacek James Vogelmann Martin Wegmann David Wilkie Cara Wilson 《Conservation biology》2015,29(2):350-359
In an effort to increase conservation effectiveness through the use of Earth observation technologies, a group of remote sensing scientists affiliated with government and academic institutions and conservation organizations identified 10 questions in conservation for which the potential to be answered would be greatly increased by use of remotely sensed data and analyses of those data. Our goals were to increase conservation practitioners’ use of remote sensing to support their work, increase collaboration between the conservation science and remote sensing communities, identify and develop new and innovative uses of remote sensing for advancing conservation science, provide guidance to space agencies on how future satellite missions can support conservation science, and generate support from the public and private sector in the use of remote sensing data to address the 10 conservation questions. We identified a broad initial list of questions on the basis of an email chain‐referral survey. We then used a workshop‐based iterative and collaborative approach to whittle the list down to these final questions (which represent 10 major themes in conservation): How can global Earth observation data be used to model species distributions and abundances? How can remote sensing improve the understanding of animal movements? How can remotely sensed ecosystem variables be used to understand, monitor, and predict ecosystem response and resilience to multiple stressors? How can remote sensing be used to monitor the effects of climate on ecosystems? How can near real‐time ecosystem monitoring catalyze threat reduction, governance and regulation compliance, and resource management decisions? How can remote sensing inform configuration of protected area networks at spatial extents relevant to populations of target species and ecosystem services? How can remote sensing‐derived products be used to value and monitor changes in ecosystem services? How can remote sensing be used to monitor and evaluate the effectiveness of conservation efforts? How does the expansion and intensification of agriculture and aquaculture alter ecosystems and the services they provide? How can remote sensing be used to determine the degree to which ecosystems are being disturbed or degraded and the effects of these changes on species and ecosystem functions? 相似文献
58.
Clow DW Peavler RS Roche J Panorska AK Thomas JM Smith S 《Environmental monitoring and assessment》2011,183(1-4):197-215
There is concern that visitor-use associated activities, such as bathing, dish washing, wastewater production, and stock animal use near lakes and streams, could cause degradation of water quality in Yosemite National Park. A study was conducted during 2004-2007 to assess patterns in nutrient and Escherichia coli (E. coli) concentrations in the Merced and Tuolumne Rivers and characterize natural background concentrations of nutrients in the park. Results indicated that nutrient and E. coli concentrations were low, even compared to other undeveloped sites in the United States. A multiple linear regression approach was used to model natural background concentrations of nutrients, with basin characteristics as explanatory variables. Modeled nitrogen concentrations increased with elevation, and modeled phosphorus concentrations increased with basin size. Observed concentrations (±uncertainty) were compared to modeled concentrations (±uncertainty) to identify sites that might be impacted by point sources of nutrients, as indicated by large model residuals. Statistically significant differences in observed and modeled concentrations were observed at only a few locations, indicating that most sites were representative of natural background conditions. The empirical modeling approach used in this study can be used to estimate natural background conditions at any point along a study reach in areas minimally impacted by development, and may be useful for setting water-quality standards in many national parks. 相似文献
59.
Santamaría-Fernández R Moreda-Piñeiro A Hill SJ 《Journal of environmental monitoring : JEM》2002,4(2):330-336
The optimisation of a simple multielement extraction method employing an experimental design approach is described. The method uses centrifugation to pass one extractant solution at varying pH through a contaminated soil sample. The nature and concentration of the acid, rate of centrifugation and time, number of sequential leachates and the ratio of extractant volume: sample weight have been studied in order to obtain the optimum conditions for extraction. A fractional factorial experimental design was performed, and the results were used to identify significance which was then evaluated by carrying out a central composite experimental approach. Once optimum conditions had been obtained, sequential leaches were analysed by ICP-AES and chemometrics were employed to identify the composition of each component. Comparisons have been made with previous studies and tentative assignments, based on well defined separated fractions and percentage compositions for individual elements, used to identify the different physico-chemical components in the sample. 相似文献
60.
We assessed the occurrence of a common river bird, the Plumbeous Redstart Rhyacornis fuliginosus, along 180 independent streams in the Indian and Nepali Himalaya. We then compared the performance of multiple discrimant analysis (MDA), logistic regression (LR) and artificial neural networks (ANN) in predicting this species’ presence or absence from 32 variables describing stream altitude, slope, habitat structure, chemistry and invertebrate abundance. Using the entire data (=training set) and a threshold for accepting presence in ANN and LR set to P≥0.5, ANN correctly classified marginally more cases (88%) than either LR (83%) or MDA (84%). Model performance was assessed from two methods of data partitioning. In a ‘leave-one-out’ approach, LR correctly predicted more cases (82%) than MDA (73%) or ANN (69%). However, in a holdout procedure, all the methods performed similarly (73–75%). All methods predicted true absence (i.e. specificity in holdout: 81–85%) better than true presence (i.e. sensitivity: 57–60%). These effects reflect species’ prevalence (=frequency of occurrence), but are seldom considered in distribution modelling. Despite occurring at only 36% of the sites, Plumbeous Redstarts are one of the most common Himalayan river birds, and problems will be greater with less common species. Both LR and ANN require an arbitrary threshold probability (often P=0.5) at which to accept species presence from model prediction. Simulations involving varied prevalence revealed that LR was particularly sensitive to threshold effects. ROC plots (received operating characteristic) were therefore used to compare model performance on test data at a range of thresholds; LR always outperformed ANN. This case study supports the need to test species’ distribution models with independent data, and to use a range of criteria in assessing model performance. ANN do not yet have major advantages over conventional multivariate methods for assessing bird distributions. LR and MDA were both more efficient in the use of computer time than ANN, and also more straightforward in providing testable hypotheses about environmental effects on occurrence. However, LR was apparently subject to chance significant effects from explanatory variables, emphasising the well-known risks of models based purely on correlative data. 相似文献