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41.
Visitor perceptions of rural landscapes: a case study in the Peak District National Park, England 总被引:1,自引:0,他引:1
Maintaining national parks is an integral policy tool to conserve rare habitats. However, because national parks are funded by taxpayers, they must also serve the needs of the general public. Increasingly, and thanks to today's diverse society, there is evidence that this creates challenges for park managers who are pulled in two opposing directions: to conserve nature on the one hand and to meet different visitor expectations on the other. This tension was explored in the Peak District National Park, a rural landscape dominated by heather moorland and sheep farming in Northern England where research was conducted to determine how social class and ethnicity shaped perceptions of the park. Results uncovered that social class played a very strong role in shaping perceptions of this region with 'middle class' respondents reacting far more favourably to the park than people from more working class backgrounds. We observed ethnicity playing a similar role, though our results are less significantly different. 相似文献
42.
An analysis of the relationship between uncertainty-reducing exploration and resource taxation 总被引:1,自引:0,他引:1
Rob Fraser 《Resources Policy》1998,24(4):199-205
This paper analyses the role of exploration as an uncertainty-reducing activity for a company facing resource taxation. Such exploration is of benefit, even to a risk-neutral company, because it enables a better decision to be made regarding extraction investment (Kretzer, 1994). This paper extends previous contributions to the economics of exploration in several areas which are of practical significance. First, exploration is analysed both in the context of a log-normally distributed resource deposit and of an ad valorem royalty. Second, the role of exploration in an ad valorem royalty regime is contrasted with that of a Resource Rent Tax. Finally, the relationship between exploration and resource taxation in situations of very divergent pre-exploration levels of uncertainty is considered. 相似文献
43.
Trisomy 9 syndrome is a rare chromosomal anomaly associated with specific patterns of multisystem dysmorphism and occasional central nervous system (CNS) malformations, the most common being the Dandy-Walker malformation. Milder anomalies are usually seen with trisomy 9 mosaicism. We report what we believe to be the first case of a baby with an isolated Dandy-Walker malformation which was diagnosed prenatally and was subsequently found to have a trisomy 9 mosaic syndrome. 相似文献
44.
45.
Experiments were conducted in the autumn and winter of 1992/93 to examine habitat use by juvenile (age 0+) Atlantic cod, Gadus morhua L., before, during and following exposure to a passive or actively foraging predator (age 3+ cod). Experiments presented groups of juvenile cod (n=5 fish/group) with one of two combinations of three substrates; (1) gravel, sand, and a patch of artificial kelp (kelp), or (2) cobble, sand, and kelp. Cobble is known to provide juvenile cod with a refuge from predation. Kelp was used to test the hypothesis that juvenile cod associate with fleshy macroalgae in nature because of the safety it provides from predators. There was little difference in habitat use by juvenile cod before, during or following exposure to a passive predator. Under these conditions, juvenile cod appeared to prefer finer grained mineral substrates and avoided the kelp. The extent of the juvenile response to a passive predator was to avoid the predator's location in the experimental tank. In contrast, juvenile cod showed a significant shift in habitat use when exposed to an actively foraging predator, hiding in cobble or, when cobble was not available, in kelp. Use of both these habitats resulted in a significant reduction in predation risk to the juvenile cod. Our results suggest that: (1) an association with kelp provides safety from predation to juvenile cod, and (2) juvenile cod are capable for assessing the risk a predator represents and adjust their response accordingly. 相似文献
46.
It is demonstrated that a relatively simple Gaussian-type diffusion simulation model can be used to give realistic estimates of the frequency of odor episodes around a point source. The model employs Pasquill's diffusion equation, Gifford's dispersion parameters, and hourly records from two meteorological stations. The theoretical calculations are compared with Likert, Guttman, self-appraisal, and unequal element scales designed to measure receptor reaction to odor-stress. Data are obtained from a field survey at a methylamine plant. Correlation analysis indicates that the model can serve as a useful method for predicting the effect of alternative abatement techniques on the annoyance reaction of receptors living in the vicinity of a proposed odor-emitting source. 相似文献
47.
Krishna Bahadur KC Laxmi Prasad Pant Evan D. G. Fraser Pratap Kumar Shrestha Dinesh Shrestha Anga Lama 《Regional Environmental Change》2016,16(5):1239-1251
Increasing on-farm crop diversity is one agroecological approach to enhancing food self-sufficiency that helps small-scale farmers keep their food systems stable by reducing risks associated with stressors, such as a pest outbreaks or droughts. But understanding how crop diversity and food self-sufficiency are related is unknown. To explore this complex relation, this study presents household data (n = 1664) from Nepal to test the hypothesis that families with high crop diversity enjoy greater household food self-sufficiency. Data are presented for three districts that are representative of three distinct agroecological regions of the country: (1) Sarlahi, which is affluent, market-oriented, and on the plains; (2) Makwanpur District in the hills, which has well-developed integrated farm production; and (3) the mountainous District of Humla, which has the poorest quality environment and is the most remote. Results show that in the Humla District, families with greater crop diversity were more self-sufficient. In contrast, farmers in Makwanpur, who have already established a high degree of crop diversity based on vegetable production, do not benefit from additional crop diversity in terms of their ability to provide for themselves. Finally, data from Sarlahi show that families’ food self-sufficiency benefits from crop diversification. We conclude that boosting crop diversity is a viable strategy for maintaining stability in food systems, but this varies depending on the accessibility of a farm and, in particular, access to markets. 相似文献
48.
This paper critically examines various methods for estimating productivity incorporating environmental effects for the Australian agricultural sector. The agricultural sector has been selected because of its strategic position in the economy of Australia. The findings of this study indicate that the application of environmentally adjusted productivity methods is a credible approach to measure productivity, in the context of sustainable development. Although the empirical findings of this research are case study specific, the results provide evidence supporting the adoption of these techniques to other sectors of the economy when measuring productivity and needing to be cognisant of sustainable development. The findings suggest that adjusting for the environmental impacts of soil erosion can result in higher or lower agricultural productivity depending on the assumptions we make regarding damage costs of erosion. It is argued in this paper that, for soil erosion in Australia, assumptions yielding higher productivity (i.e., upwardly adjusted) are justified. Finally, the findings of this study and the use of the methods presented point to important gaps in data availability. This gap needs to be addressed by policy makers if sustainable development objectives are to be credibly assessed using these techniques. 相似文献
49.
In response to federal administrative rule, the Tahoe National Forest (TNF), California, USA engaged in trail-route prioritization for motorized recreation (e.g., off-highway-vehicles) and other recreation types. The prioritization was intended to identify routes that were suitable and ill-suited for maintenance in a transportation system. A recreational user survey was conducted online (n?=?813) for user preferences for trail system characteristics, recreational use patterns, and demographics. Motorized trail users and non-motorized users displayed very clear and contrasting preferences for the same system. As has been found by previous investigators, non-motorized users expressed antagonism to motorized use on the same recreational travel system, whereas motorized users either supported multiple-use routes or dismissed non-motorized recreationists' concerns. To help the TNF plan for reduced conflict, a geographic information system (GIS) based modeling approach was used to identify recreational opportunities and potential environmental impacts of all travel routes. This GIS-based approach was based on an expert-derived rule set. The rules addressed particular environmental and recreation concerns in the TNF. Route segments were identified that could be incorporated into minimal-impact networks to support various types of recreation. The combination of potential impacts and user-benefits supported an optimization approach for an appropriate recreational travel network to minimize environmental impacts and user-conflicts in a multi-purpose system. 相似文献
50.
A.F. Fraser 《Agriculture, ecosystems & environment》1983,9(1):1-23
A major feature of our living environment consists of the domesticated animals. As their use intensifies so too does the obligation to them — and to their basic life practices — which we acquired at the moment of their domestication. Much of the behaviour of farm animals is concerned with self-maintenance, indeed, highly successful self-maintenance is the basis of animal productivity. Activities involved in such maintenance appear to fall into eight primary categories. These are basically of innate origin and include much instinctive behaviour. The use of these behaviours of reactivity, ingestion, exploration, movement, association, body care, territorialism and rest are vital to the animal in its integration and mediation with its environment. Within these eight primary systems of behaviour, numerous specific behaviours are exhibited in natural free-ranging conditions. Cattle exhibit 44 specific behaviours related to maintenance; sheep have 43 and pigs show 48. All of these above behaviours require environmental facility and where this is deficient, deficits occur in behaviour.Ethological deficits have been determined for methods of husbandry relating to the intensive production of calves, steers, sheep and pigs. Veal calves had 25 behavioural deficits, feedlot cattle had 11, housed sheep had 13 and enstalled swine had 26. These figures give indices of behavioural deprivation ranging from 25% in feedlot cattle to 56% in veal calves in stalls.Anomalous behaviour is now increasingly seen among animals which are managed under close confinement; restricted accommodation in an essentially featureles environment. Much of the anomalous behaviour which has been investigated is found to be the result of aversive environments. Anomalous behaviours are typically found in those forms of husbandry which involve intense grouping of animals and also a lack of what might be termed diversionary facilities in their environment. Reduced input of environmental stimulation and opportunity is evidently capable of acting with adverse effect on functional mediation, so as to generate anomalous forms of behaviour such as “orosthenia” — pathological oral activity. Such abnormal behaviour serves as a symptom of confinement stress. In animal production the application of ethology can provide a monitoring operation for livestock care to ensure welfare and ethological entitlement. 相似文献