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941.
Holm PE Rootzén H Borggaard OK Møberg JP Christensen TH 《Journal of environmental quality》2003,32(1):138-145
Cadmium (Cd) distribution between the soil solid phase and the soil solution is a key issue in assessing the environmental effect of Cd in the terrestrial environmental. Previous studies have shown that many individual minerals and other components found in soils can bind Cd, but most studies on whole soil samples have shown that pH is the main parameter controlling the distribution. To identify further the components that are important for Cd binding in soil we measured Cd distribution coefficients (Kd) at two fixed pH values and at low Cd loadings for 49 soils sampled in Denmark. The Kd values for Cd ranged from 5 to 3000 L kg(-1). The soils were described pedologically and characterized in detail (22 parameters) including determination of contents of the various minerals in the clay fraction. Correlating parameters were grouped and step-wise regression analysis revealed that the organic carbon content was a significant variable at both pH values. Cation exchange capacity (CEC) and gibbsite were important at the low pH (5.3) while iron oxides also were important at the high pH (6.7). None of the other clay minerals present in the soils (illite, smectite, kaolinite, hydroxy interlayered clay minerals [HIM], chlorite, quartz, microcline, plagioclase) were significant in explaining the Cd distribution coefficient. 相似文献
942.
In Rocky Mountain National Park (RMNP), aspen (Populus tremuloides Michx.) has been observed to be declining on elk (Cervus elaphus nelsoni) winter range for many decades. To support elk management decisions, the SAVANNA ecosystem model was adapted to explore interactions between elk herbivory and aspen dynamics. The simulated probability of successful vegetative regeneration for senescent aspen stands declines sharply when elk densities reach levels of 3–5 elk/km2, depending on model assumptions for the seasonal duration of elk foraging activities. For aspen stands with a substantial component of younger trees, the simulated regeneration probability declines more continuously with increasing elk density, dropping below 50% from densities at 8–14 elk/km2.At the landscape scale, simulated aspen regeneration probability under a scenario of extensive seasonal use was little affected by elk population level, when this level was above 300–600 elk (25%–50% current population) over the ca. 107 km2 winter range. This was because elk distribution was highly aggregated, so that a high density of elk occupied certain areas, even at low population levels overall. At approximately current elk population levels (1000–1200 elk), only 35%–45% of senescent aspen stands are simulated as having at least a 90% probability of regeneration, nearly all of them located on the periphery of the winter range. Successful management for aspen persistence on core winter range will likely require some combination of elk population reduction, management of elk distribution, and fencing to protect aspen suckers from elk browsing. 相似文献
943.
Levels of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) were determined in 30 Swiss cow's milk samples collected at dairy farms in the vicinity to point sources, in rural/alpine areas distant to known sources, and from tanks in large industrial milk processing plants. The contaminant concentrations in samples collected in 2001 were compared to data from analyses conducted in 1984 and 1990/1991 at the same sites. In 2001, the PCDD/F levels in milk from farms near point sources (0.63+/-0.26 ng I-TEQ/kg milk fat) are slightly but significantly higher in than milk from remote areas (0.36+/-0.09 ng I-TEQ/kg milk fat). Consumer milk collected at the processing plants had intermediary levels (0.51+/-0.19 ng I-TEQ/kg milk fat). However, milk in 2001 was significantly less contaminated than the samples collected in 1990/1991 and 1984. This trend is particularly pronounced near point sources but is also apparent in consumer milk and milk from remote areas. No geographical gradient in the atmospheric input of PCDD/F in Switzerland was found. The reduction in PCDD/F levels in dairy milk is paralleled by and correlated to the remediation of known PCDD/F emitting industries, as enforced by federal authorities. 相似文献
944.
Continuing evidence of the feminising effects of xenoestrogens on a range of wildlife species increases the need to assess the human health risk of these estrogen mimics. We have estimated the exposure of New Zealand males, females and young men to a range of naturally occurring and synthetic xenoestrogens found in food. Only estrogenic compounds that act by interaction with the estrogen receptor have been included. Theoretical plasma estrogen activity levels were derived from estrogen exposure estimates and estrogenic potency data. Theoretical plasma levels were compared with published data for specific xenoestrogens. There was surprisingly close agreement. Xenoestrogenicity from dietary intake was almost equally attributed to naturally occurring and synthetic xenoestrogens. Relative contributions for a male, for example were isoflavones (genistein and daidzein) (36%) and bisphenol A (34%) with smaller contributions from alkyl phenols (18%) and the flavonoids (phloretin and kaempferol) (12%). It is suggested that dietary xenoestrogens might have a pharmacological effect on New Zealand males and postmenopausal women, but are unlikely to be significant for pre-menopausal women. 相似文献
945.
Levels and trends of polybrominated diphenylethers and other brominated flame retardants in wildlife 总被引:5,自引:0,他引:5
Law RJ Alaee M Allchin CR Boon JP Lebeuf M Lepom P Stern GA 《Environment international》2003,29(6):757-770
In this paper, we review the available data for polybrominated diphenylethers (PBDEs) and other flame retardants in wildlife, with the exception of fishes from Europe and North America which are covered in more detail elsewhere. More data are available for PBDEs than for other compounds, and these show that some of these compounds have become widely distributed in the environment, being found in samples from Europe, Australia, Azerbaijan, North America and the Arctic. Most available data relate to birds and their eggs and marine mammals, but the results of two food web studies are also included. The detection of PBDEs in pelagic marine mammals which feed in deep offshore waters, including baleen whales, indicate that these compounds have found their way into deep-water, oceanic food webs as well as the coastal/shallow sea examples described in detail. In the North Sea study, the most marked increase in lipid-normalised concentrations of six BDE congeners occurred during transfer from predatory fish to marine mammals. In the St. Lawrence Estuary study, marked differences in the ratios observed between species suggested that some fish species may be able to metabolise BDE99.A number of time trend studies have also been conducted, notably in guillemot eggs from Sweden (1969-2000), beluga whales from the Canadian Arctic (1982-1997 and 1989-2001) and from the St. Lawrence Estuary (1988-1999), and ringed seals from the Canadian Arctic (1981-2000). In the temperate latitudes, from these and other studies (e.g. in dated sediment cores), PBDE concentrations began to rise earlier than in those from high latitudes, in line with data for production and use. These trends have now slowed in many cases. Declines could be expected in Europe for many congeners following the cessation of manufacture and use of the penta-mix formulation in the EU, though these are not yet apparent in environmental samples. In Arctic biota, however, the rapidly rising concentrations seen currently in Canada could be expected to continue for some time, reflecting continued production and use of the penta-mix formulation in North America (>95% of the world total) and the impact of long-range atmospheric transport. 相似文献
946.
Peter Newman 《Local Environment》1998,3(3):299-311
Sustainability requires innovation that involves a series of demonstrations at the local level usually seen as merely symbolic gestures. However, when tested and found to fulfil sustainability objectives, then the opportunity is available for such innovations to be mainstreamed, though often there are major obstacles to such mainstreaming. This paper examines innovations from around the world in Ecological Urban Renewal, Green Accounting, Transit Oriented Development, 'Car-Free' City Design, New Urbanist Design, and Organic City Processes. It suggests that there are many signs of hope in the emerging innovations. Mainstreaming, however, will require visionary planning, new manuals and training of professionals, and a deep commitment to democracy at the grass roots to overcome entrenched positions and institutions. The role of local government in these innovations is critical. 相似文献
947.
Spermophilus townsendii ) prey. These changes could occur directly or as a result of changes in the vegetation available as food and cover for the
ground squirrels. We assessed the effects of long-term tracking by armored vehicles by comparing 9-ha areas in sagebrush (Artemisia tridentata) -dominated shrubsteppe and bluegrass (Poa secunda) -dominated grasslands subjected to low-intensity tracking for ∼50 years with others that had not been tracked. We did not
detect any effect on ground squirrel population dynamics associated with long-term tracking. Although densities of adults
and juveniles tended to be higher in the areas exposed to such tracking, we attribute this difference to other factors that
varied spatially. To determine short-term (two-year) effects, we experimentally tracked two sagebrush and two grassland sites
with an M-1 tank after animals had begun their inactive season. In the following two active seasons we monitored squirrel
demography and behavior and vegetative characteristics on the experimentally tracked sites and compared the results with control
sites. Although we experimentally tracked ∼33% of the surface of each of four sites where ground squirrel densities were assessed,
the tracking had a detectable effect only on some herbaceous perennials and did not influence ground squirrel densities or
behavior significantly during the subsequent two active seasons. We conclude that tracking after the start of the inactive
season is likely to influence ground squirrel demography or behavior only if vegetation cover is substantially changed by
decreasing coverage of preferred food plants or increasing the coverage of annual grasses and forbs that are succulent for
only a short time each year. 相似文献
948.
Peter Dickens Peter Simmons Philip Steinberg Kenneth Button Stephen McAndrews Mary Anderson Joyce Liddle David Martin Jason Palmer Michael Woodin 《Local Environment》1997,2(1):95-109
Our Stolen Future. How man-made chemicals are threatening our fertility, intelligence and survival. T. Colborn, J. P. Myers & D. Dumanoski, 1996, Boston, Little, Brown, 306 pp. ISBN 0 316 87546, £18.99
Environmental Sociology: a social constructionist perspective. John Hannigan, 1995, London, Routledge, ISBN 0 415 112 559, £12.99
Citizen Science: a study of people, expertise and sustainable development. Alan Irwin, 1995, London, Routledge, ISBN 0 415 130 107, £13.99
The True Costs of Road Transport. David Maddison, David Pearce, Olof Johansson, Edward Calthrop, Todd Litman & Eric Verhoef, 1996, London, Earthscan, 242 pp. ISBN 185 383 2685, £10.95
Car Dependence: a report for the RAC Foundation for Motoring and the Environment. RAC Foundation for Motoring and the Environment, 1995, London, 154 pp. ISBN 086211355 5
Local Sustainability: turning sustainable development into practical action in our communities. Roger Few (Ed.), Leicester Environment City Trust, 1996, Leicester, Environ Trust, 100 pp., £28.00, [Available from: Environ Parkfield, Western Park, Leicester, LE3 6HX, UK]
Successful Environment Management in a Week. Mark Yoxon, 1996, London, Hodder & Stoughton, 96 pp. ISBN 0 340 66374 X, £6.99
Principles of Environmental and Resource Economics. H. Folmer, H. Landis Gabel & H. Opschoor (Eds), 1995, Aldershot, Edward Elgar, 512 pp. ISBN 1 85898 224 3, £85.00
The Contingent Valuation of Environmental Resources: methodological issues and research needs. David Bjornstad & James R. Khan (Eds), 1996, Cheltenham, UK and Brookfield USA, Edward Elgar, ISBN 1 858983215
Towards Sustainability. Peter Martin & Colin Hutchinson, 1996, London, Office for Public Management, £5.45
Conservation and the Consumer: understanding environmental concern. Paul Hackett, 1995, London, Routledge, 229 pp. ISBN 0 415 08096 7, £45.00 相似文献
Environmental Sociology: a social constructionist perspective. John Hannigan, 1995, London, Routledge, ISBN 0 415 112 559, £12.99
Citizen Science: a study of people, expertise and sustainable development. Alan Irwin, 1995, London, Routledge, ISBN 0 415 130 107, £13.99
The True Costs of Road Transport. David Maddison, David Pearce, Olof Johansson, Edward Calthrop, Todd Litman & Eric Verhoef, 1996, London, Earthscan, 242 pp. ISBN 185 383 2685, £10.95
Car Dependence: a report for the RAC Foundation for Motoring and the Environment. RAC Foundation for Motoring and the Environment, 1995, London, 154 pp. ISBN 086211355 5
Local Sustainability: turning sustainable development into practical action in our communities. Roger Few (Ed.), Leicester Environment City Trust, 1996, Leicester, Environ Trust, 100 pp., £28.00, [Available from: Environ Parkfield, Western Park, Leicester, LE3 6HX, UK]
Successful Environment Management in a Week. Mark Yoxon, 1996, London, Hodder & Stoughton, 96 pp. ISBN 0 340 66374 X, £6.99
Principles of Environmental and Resource Economics. H. Folmer, H. Landis Gabel & H. Opschoor (Eds), 1995, Aldershot, Edward Elgar, 512 pp. ISBN 1 85898 224 3, £85.00
The Contingent Valuation of Environmental Resources: methodological issues and research needs. David Bjornstad & James R. Khan (Eds), 1996, Cheltenham, UK and Brookfield USA, Edward Elgar, ISBN 1 858983215
Towards Sustainability. Peter Martin & Colin Hutchinson, 1996, London, Office for Public Management, £5.45
Conservation and the Consumer: understanding environmental concern. Paul Hackett, 1995, London, Routledge, 229 pp. ISBN 0 415 08096 7, £45.00 相似文献
949.
Many current audit programs are very good at determining the compliance issues at a site, but are less successful in developing long-term compliance solutions. One method for addressing these issues is the use of root cause analysis techniques. These techniques allow the facility to identify and focus on permanent solutions to compliance issues. The authors note the following: Conducting a root cause analysis is not a substantial burden on the audit team or the facility. Most information is already collected during the audit, but is not being used. Looking at the overview pattern of the root cause analysis can provide a picture of the maturity of your audit program. Pareto charts are excellent methods to convey the results of your analysis. They show both the trends of analysis and help highlight the most significant root causes. 相似文献
950.
Peter N. Lodal Jonathan L. Mahanes John M. Calvert Joseph M. Keel 《Journal of Loss Prevention in the Process Industries》1995,8(6):331-341
Conventional vacuum relief methodologies are usually protective responses; that is, they accomplish their purpose by substitution of an inert gas (usually nitrogen) for the process gases removed by an external vacuum source, or for condensable vapour collapsed by an internal process mechanism (e.g. condensation). While this approach is theoretically possible for all potential vacuum scenarios, it becomes practically impossible to implement for installations where a rapid phase change can impart near-instantaneous system pressure reductions. The procedure outlined in this paper takes a preventive approach: eliminate the source of vacuum generation before the safe lower system pressure limit is reached. For distillation and other refluxing systems, this vacuum source is usually the main overhead condenser, which is designed to collapse large volumes of condensable vapour. To eliminate the vacuum source requires elimination of the system's ability to rapidly condense vapour. This goal is accomplished by introduction of inert gas directly into the condensing system to ‘blanket’ the heat transfer surface and stop condensation. The procedure determines the rate, amount and location for introduction of inert gas. The required design data include: (i) system starting pressure, (ii) maximum allowable system vacuum, (iii) volume of the condensing system, and (iv) normal system condensing rate. By determining the rate at which the condenser removes vapour volume from the system, and designing an inert gas delivery system to meet or exceed this rate, the vacuum generation potential of the system is effectively eliminated using a much smaller quantity of inert gas than with the more traditional volume substitution methods. 相似文献