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921.
Gustin MS Ericksen J Fernandez GC 《Journal of the Air & Waste Management Association (1995)》2008,58(5):673-683
This paper describes a project that assessed the potential for mercury (Hg) release to air and water from soil amended with combustion products to simulate beneficial use. Combustion products (ash) derived from wood, sewage sludge, subbituminous coal, and a subbituminous coal-petroleum coke mixture were added to soil as agricultural supplements, soil stabilizers, and to develop low-permeability surfaces. Hg release was measured from the latter when intact and after it was broken up and mixed into the soil. Air-substrate Hg exchange was measured for all materials six times over 24 hr, providing data that reflected winter, spring, summer, and fall meteorological conditions. Dry deposition of atmospheric Hg and emission of Hg to the atmosphere were both found to be important fluxes. Measured differences in seasonal and diel (24 hr) fluxes demonstrated that to establish an annual estimate of air-substrate flux from these materials data on both of these time steps should be collected. Air-substrate exchange was highly correlated with soil and air temperature, as well as incident light. Hg releases to the atmosphere from coal and wood combustion product-amended soils to simulate an agricultural application were similar to that measured for the unamended soil, whereas releases to the air for the sludge-amended materials were higher. Hg released to soil solutions during the Synthetic Precipitation Leaching Procedure for ash-amended materials was higher than that released from soil alone. On the basis of estimates of annual releases of Hg to the air from the materials used, emissions from coal and wood ash-amended soil to simulate an agricultural application could simply be re-emission of Hg deposited by wet processes from the atmosphere; however, releases from sludge-amended materials and those generated to simulate soil stabilization and disturbed low-permeability pads include Hg indigenous to the material. 相似文献
922.
The effects of temporal and spatial changes in biological activity and biomass amount on biofilter performance were investigated in a lab-scale trickle-bed air biofilter at a toluene loading of 46.9gm(-3)h(-1) under two different experimental strategies, namely, periodic backwashing at a rate of 1h once a week and 2d starvation. Analysis of the overall reaction for toluene metabolism revealed that cell synthesis was relatively favored over toluene oxidation in the inlet section of the biofilter, but over time its oxidation became favored throughout the biofilter bed. Periodic in situ backwashing with media fluidization effectively made even spatial distribution of biomass along the bed media, by which consistent high removal performance in the biofilter has been attained. After 2d starvation, the ratio of the biofilm EPS to the total biomass increased along the media bed depth, while the total biomass in the media bed subsequently decreased. The presence of sufficient biomass and microbial activity favorably influenced biofilter reacclimation after restart-up following starvation. 相似文献
923.
Peter J. Mumby Robert S. Steneck George Roff Valerie J. Paul 《Conservation biology》2021,35(5):1473-1483
By 2004, Belize was exhibiting classic fishing down of the food web. Groupers (Serranidae) and snappers (Lutjanidae) were scarce and fisheries turned to parrotfishes (Scarinae), leading to a 41% decline in their biomass. Several policies were enacted in 2009–2010, including a moratorium on fishing parrotfish and a new marine park with no-take areas. Using a 20-year time series on reef fish and benthos, we evaluated the impact of these policies approximately 10 years after their implementation. Establishment of the Southwater Caye Marine Reserve led to a recovery of snapper at 2 out of 3 sites, but there was no evidence of recovery outside the reserve. Snapper populations in an older reserve continued to increase, implying that at least 9 years is required for their recovery. Despite concerns over the feasibility of banning parrotfish harvest once it has become a dominant fin fishery, parrotfishes returned and exceeded biomass levels prior to the fishery. The majority of these changes involved an increase in parrotfish density; species composition and adult body size generally exhibited little change. Recovery occurred equally well in reserves and areas open to other forms of fishing, implying strong compliance. Temporal trends in parrotfish grazing intensity were strongly negatively associated with the cover of macroalgae, which by 2018 had fallen to the lowest levels observed since measurements began in 1998. Coral populations remained resilient and continued to exhibit periods of net recovery after disturbance. We found that a moratorium on parrotfish harvesting is feasible and appears to help constrain macroalgae, which can otherwise impede coral resilience. 相似文献
924.
Varghese Anitha George Paul Sherely Annie Latha M. S. 《Environmental Chemistry Letters》2019,17(2):867-877
Environmental Chemistry Letters - Heavy metals and dyes are major pollutants that pose potential threat to the health of humans and ecosystems. Various technologies are available to remediate such... 相似文献
925.
Ulloa Hugo N. Constantinescu George Chang Kyoungsik Horna-Munoz Daniel Sepúlveda Steiner Oscar Bouffard Damien Wüest Alfred 《Environmental Fluid Mechanics》2019,19(3):667-698
Environmental Fluid Mechanics - We report novel results of a numerical experiment designed for examining the basin-scale hydrodynamics that control the mass, momentum, and energy distribution in a... 相似文献
926.
Amoako Gilbert Kwabena Adam Anokye M. Arthur Clement Lamboi Tackie George 《Environment, Development and Sustainability》2021,23(8):11201-11216
Environment, Development and Sustainability - Environmental sustainability has received much attention in recent times by world leaders. This is largely due to the rate at which the natural... 相似文献
927.
Pun Vivian C. Dowling Russell Mehta Sumi 《Environmental science and pollution research international》2021,28(21):26404-26412
Environmental Science and Pollution Research - Stunting is an important risk factor for early growth and health implications throughout the life course, yet until recently, studies have rarely... 相似文献
928.
Rapinski Michel Payette Fanny Sonnentag Oliver Herrmann Thora Martina Royer Marie-Jeanne S. Cuerrier Alain Siegwart Collier Laura Hermanutz Luise Guanish George 《Regional Environmental Change》2018,18(1):189-203
Regional Environmental Change - For Inuit and Naskapi living in the eastern Canadian Subarctic, local meteorological and environmental conditions (e.g., snow and ice cover extent, thickness, and... 相似文献
929.
Agyin-Birikorang S O'Connor GA Jacobs LW Makris KC Brinton SR 《Journal of environmental quality》2007,36(1):316-323
Excessive soluble P in runoff is a common cause of eutrophication in fresh waters. Evidence indicates that drinking water treatment residuals (WTRs) can reduce soluble P concentrations in P-impacted soils in the short term (days to weeks). The long-term (years) stability of WTR-immobilized P has been inferred, but validating field data are scarce. This research was undertaken at two Michigan field sites with a history of heavy manure applications to study the longevity of alum-based WTR (Al-WTR) effects on P solubility over time (7.5 yr). At both sites, amendment with Al-WTR reduced water-soluble P (WSP) concentration by >or=60% as compared to the control plots, and the Al-WTR-immobilized P (WTR-P) remained stable 7.5 yr after Al-WTR application. Rainfall simulation techniques were utilized to investigate P losses in runoff and leachate from surface soils of the field sites at 7.5 yr after Al-WTR application. At both sites, amendment with Al-WTR reduced dissolved P and bioavailable P (BAP) by >50% as compared to the control plots, showing that WTR-immobilized P remained nonlabile even 7.5 yr after Al-WTR amendment. Thus, WTR-immobilized P would not be expected to dissolve into runoff and leachate to contaminate surface waters or groundwater. Even if WTR-P is lost via erosion to surface waters, the bioavailability of the immobilized P should be minimal and should have negligible effects on water quality. However, if the WTR particles are destroyed by extreme conditions, P loss to water could pose a eutrophication risk. 相似文献
930.
Kjelland ME Kreuter UP Clendenin GA Wilkins RN Wu XB Afanador EG Grant WE 《Environmental management》2007,40(2):231-244
Fragmentation of family-owned farms and ranches has been identified as the greatest single threat to wildlife habitat, water
supply, and the long-term viability of agriculture in Texas. However, an integrative framework for insights into the pathways
of land use change has been lacking. The specific objectives of the study are to test the hypotheses that the nonagricultural
value (NAV) of rural land is a reliable indicator of trends in land fragmentation and that NAV in Texas is spatially correlated
with population density, and to explore the idea that recent changes in property size patterns are better represented by a
categorical model than by one that reflects incremental changes. We propose that the State-and-Transition model, developed
to describe the dynamics of semi-arid ecosystems, provides an appropriate conceptual framework for characterizing categorical
shifts in rural property patterns. Results suggest that changes in population density are spatially correlated with NAV and
farm size, and that rural property size is spatially correlated with changes in NAV. With increasing NAV, the proportion of
large properties tends to decrease while the area represented by small properties tends to increase. Although a correlation
exists between NAV and population density, it is the trend in NAV that appears to be a stronger predictor of land fragmentation.
The empirical relationships established herein, viewed within the conceptual framework of the State-and-Transition model,
can provide a useful tool for evaluating land use policies for maintaining critical ecosystem services delivered from privately
owned land in private land states, such as Texas. 相似文献