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571.
Ambio - Ecosystem service assessments rarely consider flows between distant regions. Hence, telecoupling effects such as conservation burdens in distant ecosystems are ignored. We identified...  相似文献   
572.
573.
Temporal variability of soil gas composition in landfill covers   总被引:1,自引:0,他引:1  
In order to assess the temporal variability of the conditions for the microbial oxidation of methane in landfill cover soils and their driving variables, gas composition at non-emissive and strongly emissive locations (hotspots) was monitored on a seasonal, daily and hourly time scale on an old, unlined landfill in northern Germany. Our study showed that the impact of the various environmental factors varied with the mode of gas transport and with the time scale considered. At non-emissive sites, governed by diffusive gas transport, soil gas composition was subject to a pronounced seasonal variation. A high extent of aeration, low methane concentrations and a high ratio of CO2 to CH4 were found across the entire depth of the soil cover during the warm and dry period, whereas in the cool and moist period aeration was less and landfill gas migrated further upward. Statistically, variation in soil gas composition was best explained by the variation in soil temperature. At locations dominated by advective gas transport and showing considerable emissions of methane, this pattern was far less pronounced with only little increase in the extent of aeration during drier periods. Here, the change of barometric pressure was found to impact soil gas composition. On a daily scale under constant conditions of temperature, gas transport at both types of locations was strongly impacted by the change in soil moisture. On an hourly scale, under constant conditions of temperature and moisture, gas migration was impacted most by the change in barometric pressure. It was shown that at diffusion-dominated sites complete methane oxidation was achieved even under adverse wintry conditions, whereas at hotspots, even under favorable dry and warm conditions, aerobic biological activity can be limited to the upper crust of the soil.  相似文献   
574.
This work assessed biodegradation, by Aspergillus, Fusarium, Penicillium and Parengyodontium fungi, of four samples of poly-ε-caprolactone (PCL), three samples of poly-l-lactide (PLA) and one sample of poly-d,l-lactide (DL-PLA) produced by ring-opening polymerization initiated by aluminium complexes of corresponding lactones. Mesophilic fungal strains actively biodegrading PCL (F. solani) and PLA (Parengyodontium album and A. calidoustus) were selected. The rate of degradation by the selected fungi was found to depend on the physicochemical and mechanical properties of the polymers (molecular weight, polydispersity, crystallinity). The most degradable poly-ε-caprolactone sample was shown to have the lowest molecular weight; the most biodegradable polylactide DL-PLA had the lowest crystallinity. Mass spectral analysis of biodegraded polymer residues showed PCL to be degraded more intensively than PLA. It is established that in the case of Parengyodontium album the colonization of the films of polypropylene composites with DL-PLA is observed, which will undoubtedly contribute to their further destruction under the influence of abiotic factors in the environment.  相似文献   
575.
Regional Environmental Change - Donors, governments, non-government organisations and humanitarian agencies are increasingly investing in disaster risk reduction (DRR) but there is limited...  相似文献   
576.
The USDA Forest Service Forest Health Monitoring (FHM) program indicators, including forest mensuration, crown condition classification, and damage and mortality indicators were used in the Cadillac Brook and Hadlock Brook watershed forests at Acadia National Park (ANP) along coastal Maine. Cadillac Brook watershed burned in a wildfire in 1947. Hadlock Brook watershed, undisturbed for several centuries, serves as the reference site. These two small watersheds have been gauged and monitored at ANP since 1998 as part of the Park Research and Intensive Monitoring of Ecosystems Network (PRIMENet). Forest vegetation at Hadlock Brook was dominated by late successional species such as Acer saccharum, Fagus grandifolia, Betula alleghaniensis, Acer rubrum and Picea rubens. Forest vegetation at Cadillac Brook, on the other hand, was younger and more diverse and included those species found in Hadlock as well as early successional species such as Betula papyrifera and Populus grandidentata. Differences in forest species composition and stand structure were attributed to the severe wildfire that affected the Cadillac Brook watershed. Overall, the forests at these ANP watersheds were healthy with a low percentage (相似文献   
577.
Diclofenac is a non-steroidal anti-inflammatory drug, which tends to be relatively persistent in the environment. Now, a fixed-bed column bioreactor filled with sediment from the creek Münzbach (Freiberg/Saxony) under aerobic conditions showed rapid removal of diclofenac in a concentration range of 3-35 microM without previous adaptation. The conversion of higher concentrations up to 260 microM was accompanied by conspicuously decreased turnover rates indicating a toxic effect of this drug or its resulting metabolic burden on the indigenous microflora. A major metabolite occurred transiently and was identified by NMR and MS to be the p-benzoquinone imine of 5-hydroxydiclofenac. Abiotic adsorption to the biofilm was shown to determine the further fate of this reactive product of 5-hydroxydiclofenac (aut-)oxidation. The apparent lack of a degradative potential for this compound as well as the failure to detect an enrichment of diclofenac-depleting microbial activity both indicate a cometabolic nature of diclofenac transformation. 4'-Hydroxy-diclofenac, the favoured transformation product of eucaryotic diclofenac metabolism, could not be identified. The ability to convert diclofenac was shown to be widespread among biofilms from different river sediments, but measured rates obviously do not correlate with the total microbial activity. In addition, application of sediments from locations exposed to communal waste water effluents did not indicate any form of adaptation measured as an increased specific diclofenac depletion rate.  相似文献   
578.
Regional Environmental Change - Protection of natural or semi-natural ecosystems is an important part of societal strategies for maintaining biodiversity, ecosystem services, and achieving overall...  相似文献   
579.
Workplace resilience is a necessity for organizations and employees given it assists them in overcoming adversity and ultimately succeeding. However, organizational scholars have largely overlooked this construct. In this Incubator, we briefly summarize extant research on workplace resilience to highlight opportunities for theory building and advancement of empirical research. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
580.
Regional Environmental Change - This paper reviews the current knowledge of climatic risks and impacts in South Asia associated with anthropogenic warming levels of 1.5–4 °C...  相似文献   
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