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51.
Sources and concentrations of indoor nitrogen dioxide in Barcelona, Spain   总被引:1,自引:0,他引:1  
Sources and concentrations of indoor nitrogen dioxide (NO2) were examined in Barcelona, Spain, during 1996-1999. A total of 340 dwellings of infants participating in a hospital-based cohort study were selected from different areas of the city. Passive filter badges were used for indoor NO2 measurement over 7-30 days. Dwelling inhabitants completed a questionnaire on housing characteristics and smoking habits. Data on outdoor NO2 concentrations were available for the entire period of the study in the areas of the city where indoor concentrations were determined. Bivariate analysis was performed to investigate relationships between indoor NO2 concentrations on one hand and outdoor NO2 concentrations, housing, and occupant characteristics on the other. Stepwise multiple linear regression was performed with variables that were found to have a significant bivariate relationship. Indoor NO2 mean values ranged between 23.57 ppb in 1996 and 27.02 ppb in 1999, with the highest yearly value of 27.82 ppb in 1997. In the same time period, mean outdoor NO2 concentration ranged between 25.26 and 25.78 ppb with a peak of 30.5 ppb in 1998. Multiple regression analysis showed that principal sources of indoor NO2 concentrations were the use of a gas cooker, the absence of an extractor fan when cooking, and cigarette smoking. The absence of central heating was also associated with higher NO2 concentrations. Finally, each ppb increase in outdoor NO2 was associated with a 1% increase in indoor concentrations.  相似文献   
52.
Structurally based ultraviolet (UV)-reflective plumage parts can be important cues in mate choice. However, it remains largely unknown if UV plumage variation can also function as a signal of social status during competitive interactions. In blue tits (Cyanistes caeruleus), the UV-reflective crown plumage functions as a female mate choice cue that probably indicates male quality, as males with higher UV reflectance have been shown to have better chances of over-winter survival. Possibly, the UV crown plumage acts as a status signal in the competition over scarce food sources during winter. To test this idea, we related dominance of individuals at an artificial food source during adverse winter conditions to spectrophotometric measurements of their crown plumage. However, while controlling for the confounding effects of sex, age, and distance from territory, we found no significant effect of crown UV reflectance on dominance. Consistent with this result, we also found no relation between crown UV reflectance and over-winter survival. We conclude that the structurally based UV reflectance of the blue tit crown feathers plays little role in competition between individuals during winter despite its importance as a cue in mate choice.  相似文献   
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54.
Feeding decisions under predation risk can be a key in the life of scavenger organisms, and tuned recognition of predation alarm cues and flexibility in the response are fundamental. The effect of injured conspecifics on the response behavior of the whelk Buccinanops globulosum to feeding opportunities was experimentally evaluated in a Patagonian Bay (40°45′S, 64°56′W, Argentina) in September 2010. The effect of sex, size, body condition, or starvation on anti-predatory behavior was assessed. The number of B. globulosum feeding on carrion was reduced by half when damaged conspecifics were present. Smaller, lighter, and starved individuals responded less to the presence of damaged conspecifics. These results indicate that, under natural conditions, feeding avoidance after detecting damaged conspecifics is a common and important anti-predatory strategy of B. globulosum and show that morphology and starvation are significant factors in the context of the trade-off between feeding and avoiding predation risk.  相似文献   
55.
In spite of the considerable literature nowadays existing on the issue of the moral exclusion of nonhuman animals, there is still work to be done concerning the characterization of the conceptual framework with which this question can be appraised. This paper intends to tackle this task. It starts by defining speciesism as the unjustified disadvantageous consideration or treatment of those who are not classified as belonging to a certain species. It then clarifies some common misunderstandings concerning what this means. Next, it rejects the idea that there are different kinds of speciesism. Such an idea may result from confusion because there are (1) different ways in which speciesism can be defended; and (2) different speciesist positions, that is, different positions that assume speciesism among their premises. Depending on whether or not these views assume other criteria for moral consideration apart from speciesism, they can be combined or simple speciesist positions. But speciesism remains in all cases the same idea. Finally, the paper examines the concept of anthropocentrism, the disadvantageous treatment or consideration of those who are not members of the human species. This notion must be conceptually distinguished from speciesism and from misothery (aversion to nonhuman animals). Anthropocentrism is shown to be refuted because it either commits a petitio principia fallacy or it falls prey to two arguments: the argument from species overlap (widely but misleadingly known as “argument from marginal cases”) and the argument from relevance. This rebuttal identifies anthropocentrism as a speciesist view.  相似文献   
56.
This paper presents a general mathematical programming model for the synthesis of distributed treatment systems for industrial effluents discharged to watersheds. In addition to addressing the economic and environmental concerns of the design, the paper introduces safety as an additional objective. A multi-objective optimization formulation is developed to simultaneously address and reconcile the various objectives. Material flow analysis (MFA) is used to track the flows and concentrations throughout the watershed system while accounting for the different sources (industrial, sanitary, agricultural, precipitation, etc.), extractions (agricultural, filtration, evaporation, etc.), and physical, biological, and chemical phenomena occurring within the watershed. Additionally, the formulation allows the installation of treatment systems for the industrial effluents. The economic, environmental, and safety aspects of these treatment units are incorporated. A case study with different scenarios for the Balsas watershed in Mexico is considered to show the applicability of the proposed approach.  相似文献   
57.
Environmental Geochemistry and Health - The thermal mineral water of Peñón de los Baños spa (Mexico City) has been used for over 500 years starting in pre-Hispanic times and...  相似文献   
58.
Environmental Fluid Mechanics - Buoyant turbulent plumes are often categorized by their geometry and described as either round plumes, issuing from a point source, or line/planar plumes, issuing...  相似文献   
59.
Environmental Science and Pollution Research - A new one-pot synthesis method optimized by a 23 experimental design was developed to prepare a biosorbent, sugarcane bagasse cellulose succinate...  相似文献   
60.
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