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481.
A bacterial strain (SeITE02), related to the species Stenotrophomonas maltophilia and resistant to selenite (SeIV) up to 50 mM in the growth medium, was isolated from rhizospheric soil of a selenium hyperaccumulator plant, the legume Astragalus bisulcatus. The influence of SeIV on the active growth of this Se-tolerant bacterial strain has been investigated in oxic conditions, along with the isolate's ability to reduce selenite to elemental selenium (Se(0)). Interestingly, concentrations of 0.5 mM SeIV were wholly reduced by strain SeITE02 in liquid culture within 52 h. Moreover, 87% of SeIV added to the growth medium at the initial concentration of 2.0 mM underwent again reduction in 120 h. Actually, a selenite-mediated induction of a sort of adaptive response to detrimental SeIV effects magnified the efficiency of SeITE02 in reducing this toxic oxyanion. Furthermore, the SeIV influence on cell morphology of strain SeITE02 was evidenced by phase-contrast and electron microscopy analyses. In particular, transmission electron microscopy (TEM)-energy-dispersive X-ray (EDX) analysis of S. maltophilia strain SeITE02, grown in presence of SeIV, showed electron-dense Se(0) granules either in the cell cytoplasm or in the extracellular space. Therefore, the capability of strain SeITE02 to quickly reduce soluble and harmful SeIV to insoluble and unavailable Se(0) may be looked at as a promising exploitable option for the setup of low-cost biological treatments tailored to manage contamination in selenium-laden effluents.  相似文献   
482.
Fire-retardant formulations are increasingly used by fire managers to control wildland fires. Their extensive use requires an assessment of their impacts in those ecosystems that could be affected by them. Recent studies indicate the potential for environmental impacts when accidentally delivered to surface waters. Yet the response of temporary wetlands, such as vernal pools, typical in Mediterranean areas, is unknown. This study reports on the emergence response of a wetland population of Daphnia curvirostris Eylmann (Cladocera, Crustacea) from sediments that were treated with a commercial fire retardant (Fire-Trol 934). Three application levels were used: 1, 3 and 5 L m(-2). The low and medium levels are in the range of manufacturer's recommendations of use in the field based on the fuel characteristics. The high level simulates local elevated concentrations that may result from inhomogeneous retardant delivery. Results indicate that emergence success decreases with increasing application rate, leading to a complete failure with application levels of 5 L m(-2). This suggests that benthic-pelagic interactions in temporary wetlands-often the primary way by which recolonization of isolated wetlands occurs-can be significantly impacted by fire retardants once they fill with fall/winter rains, thereby serving as a sensitive indicator of fire-retardant contamination. Results highlight a research need for establishing of criteria for effective, but environmentally safe use of fire retardants in the environment.  相似文献   
483.
We conducted a literature review on the biology, ecology, fishery, and protection of totoaba ( Totoaba macdonaldi ), an endemic, threatened fish of the Gulf of Calfornia, Mexico. Reinterpretation and integration of published and unpublished information enabled us to confirm and estimate specific biological parameters of the totooba, make hypothetical constructs of its life history, and to propose ideas for its preservation. In specific, we found (1) that the mean age of first reproduction of male and female totoaba are 6 and 7 years, respectively; (2) that the intrinsic rate of natural mortality was estimated as 0.268 per year and (3) that in the mid 1980s an estimated 120,300 juveniles died each year in the shrimp fishery by-catch and 6200 adults (26 kg average weight) died due to poaching. The parameters of an individual growth model for juveniles and adults were also estimated. Decreased spring water input from the Colorado River into the Gulf of California may have caused a contraction of the spawning season and a reduction of the carrying capacity of juvenile totoaba. An increase in annual survival during recent years indicates recovery of the stock that might be related to protection of adults. We argue that habitat restoration, which includes the elimination of growth and recruitment over-fishing, is critical to increasing numbers of totoaba, and thereby lifting the fishing ban, and to the delisting of totoaba.  相似文献   
484.
OBJECTIVES: The aim of this study was to determine the associations between demographics, work, lifestyle, housework, and the work ability of workers. METHODS: Employees between the ages of 20 and 69 (N = 651), employed at a Brazilian public institution, responded to a questionnaire on demographics, work, lifestyle characteristics, and work ability. RESULTS: Work ability decreased significantly with age among the women. The younger group had higher scores on the work ability index than the older age groups, except for mental resources. The logistic regression analysis showed that higher age, lower education, and long work history at the institution were significantly associated with reduced work ability. CONCLUSIONS: The progressive aging, the low level of education, and the long duration work in the studied institution were related to a reduction in work ability, which increases the risk of work disability or early retirement.  相似文献   
485.
In this paper we examine the relationship between identification with the environmental movement and support for First Nations' land claims in order to determine the potential for an environmental justice movement in British Columbia. The findings are based on survey data collected from members of a wilderness preservation movement organization based on Vancouver Island. The findings demonstrate that the stronger an individual identifies with the environmental movement, the more s/he supports linking First Nations' land claims to conservation campaigns. We conclude by proposing that the wilderness preservation movement could increase its mobilization potential and widen the scope of the movement by including First Nations' issues in their campaigns. It could do this by expanding its frame to include issues of environmental justice, thereby connecting environmental protection and fair access to resources.  相似文献   
486.
Unsustainable exploitation of wild species represents a serious threat to biodiversity and to the livelihoods of local communities and Indigenous peoples. However, managed, sustainable use has the potential to forestall extinctions, aid recovery, and meet human needs. We analyzed species-level data for 30,923 species from 13 taxonomic groups on the International Union for Conservation of Nature Red List of Threatened Species to investigate patterns of intentional biological resource use. Forty percent of species (10,098 of 25,009 species from 10 data-sufficient taxonomic groups) were used. The main purposes of use were pets, display animals, horticulture, and human consumption. Intentional use is currently contributing to elevated extinction risk for 28–29% of threatened or near threatened (NT) species (2752–2848 of 9753 species). Intentional use also affected 16% of all species used (1597–1631 of 10,098). However, 72% of used species (7291 of 10,098) were least concern, of which nearly half (3469) also had stable or improving population trends. The remainder were not documented as threatened by biological resource use, including at least 172 threatened or NT species with stable or improving populations. About one-third of species that had use documented as a threat had no targeted species management actions to directly address this threat. To improve use-related red-list data, we suggest small amendments to the relevant classification schemes and required supporting documentation. Our findings on the prevalence of sustainable and unsustainable use, and variation across taxa, can inform international policy making, including the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services, the Convention on Biological Diversity, and the Convention on International Trade in Endangered Species.  相似文献   
487.
Environmental Science and Pollution Research - The surface coating present on a marble Piety dating to the Renaissance period and stored at the Castello Sforzesco-Museum of Ancient Art (Milan,...  相似文献   
488.
Journal of Polymers and the Environment - Starch is the main predominant food reserve in plants. Its characteristics stand out from other carbohydrates providing it with several industrial...  相似文献   
489.
Journal of Polymers and the Environment - The objective of this research is to provide a new recycling method for one of the most consumed plastics today, since it is used for the manufacture of a...  相似文献   
490.
Journal of Material Cycles and Waste Management - Fluff is a shredder waste made up mostly of polymeric material generated in semi-integrated steel manufacturing plants, which is usually disposed...  相似文献   
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