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31.
The status of fish populations in 3821 lakes in Norway, Sweden and Finland was assessed in 1995-1997. The survey lakes were chosen by stratified random sampling from all (126 482) Fennoscandian lakes > or = 0.04 km2. The water chemistry of the lakes was analyzed and information on fish status was obtained by a postal inquiry. Fish population losses were most frequent in the most highly acidified region of southern Norway and least common in eastern Fennoscandia. According to the inquiry results, the number of lost stocks of brown trout (Salmo trutta), roach (Rutilus rutilus), Arctic char (Salvelinus alpinus) and perch (Perca fluviatilis) was estimated to exceed 10000. The number of stocks of these species potentially affected by the low alkalinity of lake water was estimated to exceed 11000. About 3300 lakes showed high total phosphorus (> 25 microg L(-1)) and cyprinid dominance in eastern Fennoscandia, notably southwestern Finland. This survey did not reveal any extinction of fish species due to eutrophication. One-third of the lakes had been artificially stocked with at least one new species, most often brown trout, whitefish (Coregonus lavaretus s.l.), Arctic char, rainbow trout (Oncorhynchus mykiss), pike-perch (Stizostedion lucioperca), grayling (Thymallus thymallus), pike (Esox lucius), bream (Abramis brama), tench (Tinca tinca) and European minnow (Phoxinus phoxinus). The number of artificially manipulated stocks of these species in Fennoscandian lakes was estimated to exceed 52000. Hence, the number of fish species occurring in Nordic lakes has recently been changed more by stockings than by losses of fish species through environmental changes such as acidification.  相似文献   
32.
Food and Environmental Virology - The main animal reservoirs of zoonotic hepatitis E virus (HEV) are domestic pigs and wild boars, but HEV also infects cervids. In this study, we estimated the...  相似文献   
33.
In Finland, small forest lakes and rivers in the northern part of the country are more sensitive to acidic deposition than other Finnish waters. In some lakes, acid-sensitive fish populations have declined. A nationwide survey of fishers showed that, at present, the number of fishers whose primary fishing waters are affected by airborne acidification is negligible compared to the estimated total number of adult fishers (1.1 million). The proportion of the fishers who mainly fish in water types sensitive to airborne acidification is considerable, 3% for the rivers in northern Finland and 21% for small forest lakes. There is general concern among fishers about the effects of acidification. Changes in the fishing waters are attributed to acidification by 5–10% of the fishers, although in most cases other information about the fishing waters rules out acidification as an explanation for the changes. Among those who fish in sensitive types of waters, a willingness to mitigate potential damages was reported by approximately one third of all fishers. Clear differences in the willingness to rehabilitate the fishery were observed in relation to the importance of fishing as a spare time activity and the distance between the fishing waters and a home or summer cottage.  相似文献   
34.
In this study, we present how an indoor aerosol model can be used to characterize particle emitter and predict influence of the source on indoor air quality. Particle size-resolved emission rates were quantified and the source’s influence on indoor air quality was estimated by using office model simulations. We measured particle emissions from three modern laser printers in a flow-through chamber. Measured parameters were used as input parameters for an indoor aerosol model, which we then used to quantify the particle emission rates. The same indoor aerosol model was used to simulate the effect of the particle emission source inside an office model. The office model consists of a mechanically ventilated empty room and the particle source. The aerosol from the ventilation air was a filtered urban background aerosol. The effect of the ventilation rate was studied using three different ventilation ratios 1, 2 and 3 h?1. According to the model, peak emission rates of the printers exceeded 7.0 × 108 s?1 (2.5 × 1012 h?1), and emitted mainly ultrafine particles (diameter less than 100 nm). The office model simulation results indicate that a print job increases ultrafine particle concentration to a maximum of 2.6 × 105 cm?3. Printer-emitted particles increased 6-h averaged particle concentration over eleven times compared to the background particle concentration.  相似文献   
35.
Males of many species theoretically face a fitness tradeoff between mating and parental effort, but quantification of this is rare. We estimated the magnitude of the mating opportunity cost paid by incubating male Temminck’s stints (Calidris temminckii), taking advantage of uniparental care provided by both sexes in this species. “Incubating males” provide all care for an early clutch, limiting subsequent mating possibilities. “Non-incubating” males include males that failed to obtain, lost to predation, or actively avoided incubating clutches. These males were free to pursue extrapair copulations and to mate with females laying later clutches, which females usually incubate themselves. Male incubation classes did not differ in measures of quality, and many individuals changed classes between years, suggesting the use of conditional reproductive tactics. However, specialist non-incubators may also exist. Using microsatellites to assign parentage, we compare males’ total fertilizations and the subset “free of care” fertilizations between incubation classes. Incubators were more likely to gain at least one fertilization per season and averaged one more per season than non-incubators. However, successful non-incubators were more likely to gain “free of care” fertilizations, averaging two more than successful incubators. The relative success of male incubation classes also changed with local sex ratios. With higher female proportions, non-incubators gained disproportionately more offspring, suggesting that the use of tactics should be partly determined by the availability of potentially incubating females. Overall, we estimate the opportunity cost of incubating to be 13–25 % of the potential annual reproductive output.  相似文献   
36.
37.
The current landfill gas (LFG) management (based on flaring and utilization for heat generation of the collected gas) and three potential future gas management options (LFG flaring, heat generation and combined heat and power generation) for the Old Ämmässuo landfill (Espoo, Finland) were evaluated by life-cycle assessment modeling. The evaluation accounts for all resource utilization and emissions to the environment related to the gas generation and management for a life-cycle time horizon of 100 yr. The assessment criteria comprise standard impact categories (global warming, photo-chemical ozone formation, stratospheric ozone depletion, acidification and nutrient enrichment) and toxicity-related impact categories (human toxicity via soil, via water and via air, eco-toxicity in soil and in water chronic).The results of the life-cycle impact assessment show that disperse emissions of LFG from the landfill surface determine the highest potential impacts in terms of global warming, stratospheric ozone depletion, and human toxicity via soil. Conversely, the impact potentials estimated for other categories are numerically-negative when the collected LFG is utilized for energy generation, demonstrating that net environmental savings can be obtained. Such savings are proportional to the amount of gas utilized for energy generation and the gas energy recovery efficiency achieved, which thus have to be regarded as key parameters. As a result, the overall best performance is found for the heat generation option – as it has the highest LFG utilization/energy recovery rates – whereas the worst performance is estimated for the LFG flaring option, as no LFG is here utilized for energy generation.Therefore, to reduce the environmental burdens caused by the current gas management strategy, more LFG should be used for energy generation. This inherently requires a superior LFG capture rate that, in addition, would reduce fugitive emissions of LFG from the landfill surface, bringing further environmental benefits.  相似文献   
38.
In the European Union, Council Directive 96/82/EC requires operators producing, using, or handling significant amounts of dangerous substances to improve their safety management systems in order to better manage the major accident potentials deriving from human error.

A new safety management system for the Viikinmäki wastewater treatment plant in Helsinki, Finland, was implemented in this study. The system was designed to comply with both the new safety liabilities and the requirements of OHSAS 18001 (British Standards Institute, 1999). During the implementation phase experiences were gathered from the development processes in this small organisation.

The complete documentation was placed in the intranet of the plant. Hyperlinks between documents were created to ensure convenience of use. Documentation was made accessible for all workers from every workstation.  相似文献   
39.
本文调查研究了在目前和未来气候条件下的波罗的海海冰.采用了罗斯比区域大气-海洋模型进行了一系列为时30年的时间片试验.对于两个驱动全球模型HadAM3H和ECHAM4/OPYC3中每一个,都根据SRESA2和B2辐射情景进行一次对照操作(1961~1990年)和两次情景操作(2071~2100年).波罗的海中未来海冰量将平均减少83%.波的尼亚海,芬兰湾和里加湾的大片海域以及芬兰西南群岛的外部将基本上变成无冰区.本文提出的情景是用来研究气候变化对波罗的海环斑海豹(Phoca hispida botnica)的影响.气候变化看来是对所有南方种群的主要威胁.惟一还算不错的冬季海冰生境只限于波的尼亚湾.  相似文献   
40.
Method for Selection of Old-Forest Reserves   总被引:2,自引:0,他引:2  
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