首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   8篇
  免费   0篇
安全科学   1篇
环保管理   1篇
污染及防治   6篇
  2013年   1篇
  2007年   1篇
  2006年   1篇
  2004年   1篇
  2002年   1篇
  1999年   1篇
  1997年   1篇
  1994年   1篇
排序方式: 共有8条查询结果,搜索用时 31 毫秒
1
1.
As a member of the European Union, Finland has committed itself to creating an environmental policy for agriculture. The aims of this study were to evaluate visual impacts of the General Agri-Environmental Protection Scheme (GAEPS) and Supplementary Protection Scheme (SPS) and general attitudes towards some activities in those policies and furthermore to examine the suitability of the method of Alho et al. (2001) for the scenic beauty assessment. The study areas consisted of three original, untreated, and 15 modified rural landscapes representing a variety of different activities. The scenic beauty of the landscapes was evaluated through pairwise comparisons of the responses of 68 people. Furthermore, attitudes towards environmental values, water protection, buffer strips and subsidies to agriculture were obtained. The respondents found the maintained buffer strips more pleasing than unmaintained strips and considered that the quality of watercourses was increased by buffer strips along them. A suitable width for the buffer strip along main ditches, brooks and waterways was regarded, on average, to be wider than the current recommendations. Although the opinions of farmers were basically in line with the existing recommendations, farmers' opininons on the second and third most important effects of buffer strips, an increase in weeds and a decrease in cultivated land, clearly differed from those of the other respondents. Afforestation, lack of building maintenance and abandoned fields were considered to be the most important factors impacting rural landscapes. This study indicates that the Finnish Agri-Environmental Protection Schemes have had positive impacts on the visual quality of landscapes. Attitudes towards other impacts are contradictory. This study also showed the improvement of the Alho et al. (2001) method in these kinds of studies relative to other methods of pairwise comparisons.  相似文献   
2.
Accumulation and toxicity of waterborne bisphenol A were studied in landlocked salmon (Salmo salar m. sebago) yolk-sac fry. In a short-term (96 h) exposure to five bisphenol A concentrations yolk-sac fry had higher accumulation rates and bioconcentration factors (BCF96) than earlier studies have shown for salmon eggs. Furthermore, the conditional uptake rate constant tended to decrease as exposure concentration increased. Fry were also exposed to bisphenol A for 42 days at three concentrations (10, 100 and 1000 microg/l), and changes in behaviour, morphology and histological structure were observed. After 6 days of exposure, the highest concentration (1000 microg/l) of bisphenol A caused fluid accumulation (oedema) in the yolk sac and haemorrhages in the front part of the yolk sac and in the head around the gill arches. Later on, the fry at 1000 microg/l showed phlegmatic behaviour and had darker skin coloration than the fry in the other treatments. At the two highest concentrations (100 and 1000 microg/l) histological changes were seen in liver cell nuclei, where strongly stained fragments were observed. In the control fry and the fry exposed to 10 microg/l the nucleolus was clearly visible and spherical in shape and no strongly stained fragments were present. This study shows that high concentrations of bisphenol A may have both morphological and histological effects on salmon yolk-sac fry.  相似文献   
3.
Aliphatic liquid as a basic fuel was incinerated in a laboratory scale pilot plant. Inorganic chlorine and organic chlorine mixed with basic fuel were used as additive chemicals. Sodium chloride (NaCl) and tetrachloroethylene (C2Cl4) were used as the sources of inorganic and organic chlorine. Combustion parameters were adjusted for optimum combustion and, consequently, the amount of particles in flue gases was low. The concentrations of chlorine in flue gases were high enough for possible formation reactions of organic chlorinated compounds in all of the chlorine input tests. An increase in chlorine input did not significantly increase the amounts of highly chlorinated organic compounds, like PCDD/Fs. The main result was that chlorophenol concentrations increased in parallel with organic chlorine input. Comparing organic chlorine to inorganic chlorine tests showed that more highly substituted PCDD/F congeners were formed when organic chlorine was the additive chlorine source. The formation of highly chlorinated organic compounds such as PCDD/Fs requires not only chlorine and aliphatic fuel to be formed, but some catalysts are also needed.  相似文献   
4.
A simple procedure for correcting loading effects of aethalometer data   总被引:1,自引:0,他引:1  
A simple method for correcting for the loading effects of aethalometer data is presented. The formula BC(CORRECTED) = (1 + k x ATN) x BC(NONCORRECTED), where ATN is the attenuation and BC is black carbon, was used for correcting aethalometer data obtained from measurements at three different sites: a subway station in Helsinki, an urban background measurement station in Helsinki, and a rural station in Hyyti?l? in central Finland. The BC data were compared with simultaneously measured aerosol volume concentrations (V). After the correction algorithm, the BC-to-V ratio remained relatively stable between consequent filter spots, which can be regarded as indirect evidence that the correction algorithm works. The k value calculated from the outdoor sites had a clear seasonal cycle that could be explained by darker aerosol in winter than in summer. When the contribution of BC to the total aerosol volume was high, the k factor was high and vice versa. In winter, the k values at all wavelengths were very close to that obtained from the subway station data. In summer, the k value was wavelength dependent and often negative. When the k value is negative, the noncorrected BC concentrations overestimated the true concentrations.  相似文献   
5.
Emissions of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) from municipal waste incineration are currently a subject of considerable public concern because of their extreme toxicity. PCDD/F formation in incineration processes is being studied widely, but little work has been done on their inhibition. We studied the effect of two liquid inhibitors, sodium ammonium hydrogen phosphate (NAHF) and urea (H2NCONH2), on PCDD/F formation in the combustion of liquid fuel doped with copper and chlorine using a pilot-scale plant. The inhibitors were injected into the flue gas stream at a temperature of 725 degrees C, whereupon both the chlorophenol and PCDD/F concentrations decreased. Particle-phase PCDD/F concentrations in particular decreased by up to 90% with NAHF and 70% with urea, but gas phase reduction took place only with urea. The results suggest that the formation of PCDD/Fs is hindered in the particle phase at the early stages of the PCDD/F formation chain, probably even before precursors such as chlorophenols have been formed. As a consequence, particle-phase PCDD/F concentrations can be predicted by a PLS (partial least-squares) approach with the gas-phase chlorophenol concentrations as independent variables. The structure and partial charges of Cu(+)-urea complex were calculated by the HF/3-21G basis set.  相似文献   
6.
This study examined changes in work techniques and musculoskeletal symptoms after occupationally oriented medical rehabilitation arranged for 21 hairdressers who were experiencing neck-shoulder or back pain but were still able to work. OWAS (Ovako Working Posture Analysing System) analyses of working postures and questionnaire data were obtained at the beginning of the courses and one and a half years later. The participants worked with their back bent and twisted or their arms at or over shoulder level more seldom (p < .0001) at the end of the follow-up than at the beginning of the rehabilitation. Subjective work-related physical and mental strain had decreased by 45.4% (p < .001) and 27.1% (p < .05), respectively, and subjective neck and back pain by 40.0% (p < .0 1 ) and 45.3% (p < .01). respectively. This’study suggests that occupationally oriented medical rehabilitation can have significant and long-lasting effects on the rehabilitee’s work techniques and subjective well-being.  相似文献   
7.
This study shows the catalyzing effects of iron and copper on the formation of chlorinated compounds such as chlorobenzenes (ClBzs), chlorophenols (CIPhs), polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs). Both total concentrations and congener distributions have been studied. The parameters and conditions varied during the combustion tests were the complete and incomplete combustion and the metal and chlorine addition. The incomplete combustion promoted the formation of organic chlorinated compounds in flue gas particles. Highly chlorinated congeners of PCDD/F were dominant in the flue gas particles, whereas the importance of lower chlorinated congener were increased in the gas phase. In the complete combustion conditions the concentrations of PCDD/Fs increased when the degree of chlorination were high, nevertheless the concentrations of tetra and penta PCDD/Fs were higher in the gas phase than the concentrations in the fly ash particles. Organic chlorine promoted the formation of chlorinated compounds more effectively than inorganic chlorine, which instead promoted the formation of PCDD/Fs in the gas phase, especially with copper catalyst. Different concentration levels of chlorinated compounds were observed in the gas phase and in particles when the chlorine source and combustion conditions were varied from incomplete to optimum conditions. Both copper and iron seem to have a catalytic effect on PCDD/F formation.  相似文献   
8.
Eleven white-tailed sea eagles (WSEs) (Haliaeetus albicilla) collected in Finland between 1994 and 2001 were examined for their causes of death, including analyses of ubiquitous environmental contaminants and parasites. Four WSEs died due to electrocution. Two were lead poisoned and another had fragments of a lead bullet in its gizzard. An 11-year-old female drowned entangled in fishing gear, but also had mercury levels in its liver and kidneys known for detrimental physiological effects. One WSE was evidently killed by an intraspecific conflict, which was also assumed to be with another bird. The mortality factors of two WSEs could not be clarified, but one had a lead level of 4.604 microg g(-1) in its liver, indicating high lead exposure at a clinically relevant concentration. All organ levels of chlorinated pesticides, polychlorinated biphenyls, and cadmium were moderate and not harmful for birds of prey. Seven helminth species, but no ectoparasites or coccidians, were found in 8 of 10 WSEs investigated for parasites. The highest prevalence of 40% was found for the liver fluke Metorchis billis, but no severe parasitosis was diagnosed for the eagles. The two acanthocephalan species Corynosoma semerme and Polymorphus meyeri are both new records for WSEs.  相似文献   
1
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号