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941.
Salve PR Satapathy DR Katpatal YB Wate SR 《Environmental monitoring and assessment》2007,133(1-3):87-98
Stratospheric input and photochemical ozone formation in the troposphere are the two main sources determining the ozone levels
in the surface layer of the atmosphere. Because of the importance of ozone in controlling the atmospheric chemistry and its
decisive role in the heat balance of atmosphere, leading to climate change, the examination of its formation and destruction
are of great interest. This study characterized the distribution of Ground level Ozone (GLO) in Chandrapur district is lying
between 19°25′N to 20°45′N and 78°50′E to 80°10′E. Continuous ozone analyzer was used to quantify GLO at thirteen locations
fixed by Global Positioning System (GPS) during the winter of 2005–2006. The daily GLO at all the locations ranged between
6.4 and 24.8 ppbv with an average and standard deviation of 14.9 ± 6.5 ppbv. The maximum and minimum concentration occurs
during 1300–1600 h and 0300–0500 h may be due to high solar radiation facilitating photochemical production of O3 and downward mixing from the overlying air mass and in situ destruction of ozone by deposition and/or the reaction between
O3 and NO. GIS based spatial distribution of GLO in Chandrapur district is indicates that the central core of the district and
southern sites experienced elevated levels of GLO relative to the northern and western areas. The sites near by Chandrapur
city are particularly affected by elevated GLO. The average variation of GLO with temperature shows a significant correlation
of r = 0.55 indicating a direct relationship between GLO and temperature. Similarly an attempt has been made to compare the GLO
monitored data in Chandrapur district with the reported values for other locations in Indian cities. This generated database
helps regulatory agencies to identify locations where the natural resources and human health could be at risk. 相似文献
942.
Pliura A Baliuckiene A Baliuckas V 《Environmental pollution (Barking, Essex : 1987)》2008,156(1):152-161
Phenogenetic response of silver birch populations and half-sib families to separate and combined elevated ozone (O3) concentrations and ultraviolet-B (UV-B) radiation dozes was studied at juvenile age in the climatic chambers. Significant population and family effects were found for seedling height, lamina width, and leaf damage. The exposure to UV-B radiation decreased genetic variation at the stage of seed germination. Complex exposure to UV-B and O3 caused an increase of genetic variation at the stage of intensive seedling growth: seedling height genetic variation in separate treatments increased from 23.7–38.6 to 33.7–65.7%, the increase for lamina width was from 10.2–13.9 to 13.6–31.8%. Different populations and families demonstrated differing response to elevated complex UV-B and O3 exposure. Changes of genetic intra-population variation were population-specific. Such changes in genetic variation under the impact of stressors can alter adaptation, stability, and competitive ability of regenerating populations in a hardly predictive way. 相似文献
943.
A regression model based on the provincial energy consumption data was developed to calculate the monthly proportions of residential energy consumption compared to the total year volume. This model was also validated by comparing with some survey and statistical data. With this model, a PAHs emission inventory with seasonal variation was developed. The seasonal variations of different sources in different regions of China and the spatial distribution of the major sources in different seasons were also achieved. The PAHs emissions were larger in the winter than in the summer, with a difference of about 1.3-folds between the months with the largest and the smallest emissions. Residential solid fuel combustion dominated the pattern of seasonal variation with the winter-time emissions as much as 1.6 times as that in the summer, while the emissions from wild fires and open fire straw burning was mainly concentrated during the spring and summer. 相似文献
944.
Schipper AM Wijnhoven S Leuven RS Ragas AM Hendriks AJ 《Environmental pollution (Barking, Essex : 1987)》2008,151(1):17-26
Soil metal concentrations, inundation characteristics and abundances of 14 arthropod taxa were investigated in a moderately contaminated lowland floodplain along the Rhine River and compared to the hinterland. Internal metal concentrations were determined for the orders of Coleoptera (beetles) and Araneida (spiders) and were related to soil concentrations. The floodplain was characterized by larger arthropod abundance than the hinterland, in spite of recurrent inundations and higher soil metal concentrations. Most arthropod taxa showed increasing abundance with decreasing distance to the river channel and increasing average inundation duration. For Cd, Cu, Pb and Zn, significant relations were found between arthropod concentrations and concentrations in soil. Significant relations were few but positive, indicating that increasing soil concentrations result in increasing body burdens in arthropods. For arthropod-eating vertebrates, these results might imply that larger prey availability in the floodplain coincides with higher metal concentrations in prey, possibly leading to increased exposure to metal contamination. 相似文献
945.
We examined the effect of subsample size on the accuracy of information obtained from aquatic macroinvertebrate assemblage
samples. Subsamples containing 100 organisms or 300 organisms were compared on the bases of processing time and the ability
to discern ecological differences among samples. Independently of subsample size, assemblages differed between study streams,
primarily reflecting an intermittent vs. permanent stream difference, and between seasons at most streams. It required, on
average, two additional hours to process the larger subsamples. Larger subsamples gave significantly higher estimates of total
richness and Ephemeroptera, Plecoptera, and Trichoptera (EPT) richness, but the relative abundances of many assemblage subsets
(e.g., EPT organisms and most functional feeding groups) were similar using both subsample sizes. Larger subsamples did not
typically enhance the ability to discriminate between samples from different seasons, but did more accurately distinguish
among streams when differences were subtle. They also appeared to avoid Type I error in comparisons of compositionally similar
reaches within a study stream. 相似文献
946.
It is significant to design best management practices (BMPs) and determine the proper BMPs placement for the purpose that
can not only satisfy the water quantity and water quality standard, but also lower the total cost of BMPs. The spatial rainfall
variability can have much effect on its relative runoff and non-point source pollution (NPSP). Meantime, the optimal design
and placement of BMPs would be different as well. The objective of this study was to discuss the relationship between the
spatial variability of rainfall and the optimal BMPs placements. Three synthetic rainfall storms with varied spatial distributions,
including uniform rainfall, downstream rainfall and upstream rainfall, were designed. WinVAST model was applied to predict
runoff and NPSP. Additionally, detention pond and swale were selected for being structural BMPs. Scatter search was applied
to find the optimal BMPs placement. The results show that mostly the total cost of BMPs is higher in downstream rainfall than
in upstream rainfall or uniform rainfall. Moreover, the cost of detention pond is much higher than swale. Thus, even though
detention pond has larger efficiency for lowering peak flow and pollutant exports, it is not always the determined set in
each subbasin. 相似文献
947.
中国茸鹿品种(品系)的随机扩增多态DNA(RAPD)研究 总被引:8,自引:0,他引:8
采用随机扩增多态DNA技术研究了5个茸鹿品种(品系)75个个体的遗传变异关系。在所使用的41个引物中,有40个引物扩增出多态谱带,共检测到395条扩增片段,其中259条(65.6%)出现变异,用Shaknnon指数计算了5个品种(品系)的遗传变异及其遗传变异在群体内和群体间的分布。利用Nei氏片段共享度计算了75个个体间的遗传距离,用UPGMA聚类法构建了75个个体的系统发育树状图,反映5个茸鹿品 相似文献
948.
949.
Manuel E. Ortiz-Santaliestra María José Fernández-Benéitez 《Environmental pollution (Barking, Essex : 1987)》2010,158(3):934-940
The negative effects of pollution on amphibians are especially high when animals are additionally stressed by other environmental factors such as water salinity. However, the stress provoked by salinity may vary among populations because of adaptation processes. We tested the combined effect of a common fertilizer, ammonium nitrate (0-90.3 mg N-NO3NH4/L), and water salinity (0-2‰) on embryos of two Pelophylax perezi populations from ponds with different salinity concentrations. Embryos exposed to the fertilizer were up to 17% smaller than controls. Survival rates of embryos exposed to a single stressor were always below 10%. The exposure to both stressors concurrently increased mortality rate (>95%) of embryos from freshwater. Since the fertilizer was lethal only when individuals were stressed by the salinity, it did not cause lethal effects on embryos naturally adapted to saline environments. Our results underscore the importance of testing multiple stressors when analyzing amphibian sensitivity to environmental pollution. 相似文献
950.
通过对乌鲁木齐市新装修居室空气连续6个月的追踪监测,分析新装修居室甲醛、总挥发性有机物浓度的动态变化规律。结果表明,室内甲醛的浓度随装修竣工后时间的增加呈现降低趋势,但到第6个月为止,绝大部分住户室内空气甲醛浓度依然超标。总挥发性有机物的浓度降低趋势较为明显,到第5个月时,绝大部分住户室内空气总挥发性有机物浓度达到国家标准限值的要求。室内空气甲醛浓度的降低是一个长期缓慢的过程,居室内甲醛污染对人体健康的危害应引起人们的足够重视。 相似文献