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71.
Summary With the passage of the Land Commission Act in April 1974, the province of British Columbia emerged as one of the leading innovators in agricultural land protection in North America. The British Columbia programme is unique, in that it encompasses a variety of incentives and disincentives to restrict the development of agricultural resources. While evidence suggests that the program has been quite successful, administrative weaknesses could endanger long-term viability. Regardless of the potential problems, British Columbia's experiences provide valuable lessons for other North American governments.Owen J. Furuseth is an Assistant Professor of Geography & Earth Sciences at the University of North Carolina at Charlotte. He received his A.B. degree (1971) in geography and urban planning from East Carolina University and an MA (1973) from the same institution in geography. His Ph.D. (1978) was earned in geography at Oregon State University.Prior to his current academic appointment he was an Associate Planner with the Jacksonville Area Planning Board in Jacksonville, Florida. His responsibilities with the agency included land use and environmental planning.His primary research interests are in the areas of agricultural land alienation, and policies to reduce these losses. During 1980–1981, Furuseth was a NATO Postdoctoral Fellow affiliated with the graduate program in Natural Resources Management at Simon Fraser University, British Columbia, Canada. The research reported in this paper was carried out and completed while he was in Canada.  相似文献   
72.
Management strategies to reduce the risks to human life and property from wildfire commonly involve burning native vegetation. However, planned burning can conflict with other societal objectives such as human health and biodiversity conservation. These conflicts are likely to intensify as fire regimes change under future climates and as growing human populations encroach farther into fire‐prone ecosystems. Decisions about managing fire risks are therefore complex and warrant more sophisticated approaches than are typically used. We applied a multicriteria decision making approach (MCDA) with the potential to improve fire management outcomes to the case of a highly populated, biodiverse, and flammable wildland–urban interface. We considered the effects of 22 planned burning options on 8 objectives: house protection, maximizing water quality, minimizing carbon emissions and impacts on human health, and minimizing declines of 5 distinct species types. The MCDA identified a small number of management options (burning forest adjacent to houses) that performed well for most objectives, but not for one species type (arboreal mammal) or for water quality. Although MCDA made the conflict between objectives explicit, resolution of the problem depended on the weighting assigned to each objective. Additive weighting of criteria traded off the arboreal mammal and water quality objectives for other objectives. Multiplicative weighting identified scenarios that avoided poor outcomes for any objective, which is important for avoiding potentially irreversible biodiversity losses. To distinguish reliably among management options, future work should focus on reducing uncertainty in outcomes across a range of objectives. Considering management actions that have more predictable outcomes than landscape fuel management will be important. We found that, where data were adequate, an MCDA can support decision making in the complex and often conflicted area of fire management.  相似文献   
73.
Hematological responses of broiler chicken exposed to simulated crude petroleum emissions at varying distances over a period of 16 h daily were evaluated for 56 days in a poultry house. The burning of crude petroleum was simulated with a specially designed burner. The measured distances were 4, 8, or 12 m from the flame point. Control birds were located in a separate poultry building without the flame treatment. Gaseous emissions from the burning crude oil were monitored. Proprietory broiler starter and finisher diets were fed ad libitum. Blood samples were taken at the fourth and eighth weeks for hematological assay from each treatment. The hematological parameters assayed were hemoglobin (Hb), packed cell volume (PCV), white blood cells (WBC), neutrophils, and lymphocytes. Results indicated that the treatment did not significantly affect the Hb, PCV, and WBC constituents. Neutrophils significantly decreased while lymphocytes increased. The age of birds significantly increased Hb, PCV, and WBC levels in the blood.  相似文献   
74.
Hormonal responses of broiler chickens exposed to crude petroleum flame and fumes at varying distances over a period of 16 h daily were evaluated for 56 days in a poultry house. The burning of crude petroleum was simulated in a designed burner. The measured distances were 4, 8, or 12 m from the flame point. The experimental design was a two-factor factorial in a completely randomized design (CRD) with factor A as distance from the crude petroleum flame and factor B was the age of birds in weeks. One hundred and eighty Anak day-old broiler chickens were divided into four groups of 45 birds each, replicated thrice at 15 birds per replicate. Control birds were located in a separate poultry building without the flame treatment. Gaseous emissions from the burning crude oil were monitored. Proprietary broiler starter and finisher diets were fed ad libitum. Blood samples were taken at the fourth and eighth week for hormone radioimmunoassay from each treatment. The hormones assayed were growth hormone (GH), thyroxine (T4,), and adrenaline. Results indicated that treatments did not significantly alter hormonal levels. The age of birds significantly affected the levels of all three hormones measured.  相似文献   
75.
Social amoebae aggregate to form a multicellular slug that migrates some distance. Most species produce a stalk during migration, but some do not. We show that Dictyostelium giganteum, a species that produces stalk during migration, is able to traverse small gaps and utilize bacterial resources following gap traversal by shedding live cells. In contrast, we found that Dictyostelium discoideum, a species that does not produce stalk during migration, can traverse gaps only when in the presence of other species’ stalks or other thin filaments. These findings suggest that production of stalk during migration allows traversal of gaps that commonly occurs in soil and leaf litter. Considering the functional consequences of a stalked migration may be important for explaining the evolutionary maintenance or loss of a stalked migration.  相似文献   
76.
77.
In 2017 the paper ‘The Sustainable Development Oxymoron: Quantifying and Modelling the Incompatibility of Sustainable Development Goals’ was published, showing that there is a conflict between socio-economic development goals and ecological sustainability goals using cross-country time-series data. The authors looked at production-based CO2 emissions to measure and model the 13th SDG goal addressing climate change. Their models showed that production-based CO2 emissions were stalling or even decreasing in rich countries, which suggests that other countries are also likely to see stalling and decrease in their CO2 emissions once they become rich. However, this conclusion can be challenged when accounting for consumption-based CO2 emissions rather than production-based CO2 emissions. In this follow-up paper, we re-run some of the analyses performed in the original paper making use of consumption-based CO2 emissions. The analysis confirms the inherent SDG conflict between socio-economic and ecological SDGs. But, this new analysis demonstrates that from a consumption perspective the trend of stalling or decreasing CO2 emissions is reversed, with natural depletion costs being exported to poorer countries. Despite this new perspective on CO2 emissions, the conflict between SDG goals can still be avoided by making investments in public health, education and renewable energy, as suggested in the original paper.  相似文献   
78.
On enactment, both the National Environmental Policy Act (NEPA), 1970 of the US and the Resource Management Act (RMA), 1991 of New Zealand received accolades for innovativeness. However, is such praise justified when these acts are explored through the literature on policy innovation? This paper suggests that it is. More importantly, recognizing how different attributes of innovation contribute to having a policy adopted suggests what the crafters of future environmental policies might do well to consider. It is critical to attend to the political climate in which a policy is being drafted.  相似文献   
79.
In response to continued public concern sparked by the loss of open space and greenbelts around American cities, greenways have gained nationwide popularity as a land conservation strategy. This study examines the socioeconomic, demographic, and locational characteristics of greenway users. Three hundred twenty users on four trails of the Capital Area Greenway System in Raleigh, North Carolina, were surveyed. The Raleigh system is extensive, providing 43.7 km (27 mi) of trails, thus allowing examination of greenway use in a variety of settings. The survey findings indicated that most patrons were drawn from within an 8.05-km (5-mi) radius of the greenway. The typical Capital Area Greenway user is a white female between the age of 16 and 34 with no children. Socioeconomically, greenway users are employed, well-educated, and have above average incomes. A disproportionate share of greenway visitors belong to an environmental group.  相似文献   
80.
The ratios of polyunsaturated fatty acids in the lipids of hatchery-reared plaice [Pleuronectes platessa (L.)] maintained on a diet containing corn oil and freeze-dried cod muscle accurately reflect ratios of polyunsaturated fatty acids in the diet. Such plaice have much greater levels of triglycerides in both their livers and extrahepatic tissues than wild plaice of comparable size; the total amount of 22:6 3 acid in triglycerides of the two groups is, however, very similar. Transfer of experimental plaice to a fat-free diet caused a marked depletion of triglycerides from both livers and extrahepatic tissues with almost all fatty acids being reduced in amount. Addition of 12:0 and 14:0 ethyl esters (4% of each) to the fat-free diet caused some accumulation of triglycerides in extrahepatic tissues. Further addition of 18:2 6 and 18:3 3 acids (both at levels of 0.4%) to the diet caused an accumulation of triglycerides in the liver. These triglycerides had increased levels of saturated and monounsaturated fatty acids up to C 18 but the levels of higher polyunsaturated fatty acids were not inereased. There was relatively little change in the fatty acids of phospholipids throughout these experimental dietary regimes. The levels of phospholipids were constant and very similar to those of wild plaice. The results indicate: (1) plaice fed a diet relatively low in 22:6 3 acid may accumulate relatively large amounts of triglyceride in order to store adequate amounts of 22:6 3 acid; (2) plaice are capable of synthesising saturated and mono-unsaturated fatty acids up to C 18 in the presence of dietary 12:0 and 14:0 acids; (3) 18:2 6 and 18:3 3 acids in the diet do not undergo chain elongation and further desaturation in plaice with the dietary regimes we used.  相似文献   
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