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Spatial (10 different locations) and temporal (2 years) changes in characteristics of the Marmara Sea Sediments were monitored to determine interactions between the chemical and microbial diversity. The sediments were rich in terms of hydrocarbon, nitrate, Ni and microbial cell content. Denitrifying, sulfate reducing, fermentative and methanogenic organisms were co-abundant in 15 cm below the sea floor. The local variations in the sediments’ characteristics were more distinctive than the temporal ones. The sulfate and nitrate contents were the main drivers of the changes in the microbial community compositions. N and P were limited for microbial growth in the sediments, and their levels determined the total cell abundance and activity. Seasonal shifts in temperatures of the shallow sediments were also reflected in the active cell abundances. It was concluded that the Marmara Sea is a promising ecosystem for the further investigation of the ecologically important microbial processes. 相似文献
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Roy BK 《GeoJournal》1991,23(3):257-268
This is an exploratory study made on the basis of migration data of two censuses of 1971 and 1981. It tries to compare some of the important variables of mobility in terms of POB (place of birth) and POLR (place of last residence) which have reacted into the change of usual residence of people causing thereby shift of population. The subject being complex and vast, it may be difficult to project all possible situations at one place. However, the readers may try to test some of the findings more fruitfully by field oriented investigations specially leading to establish various social-economic fall outs. Migration study is processional in the evaluation of population problems which has folded into its orbit, in real sense of the term — idealised migration policies. In the country, like ours, it is essential to really spell out some policy to check urban swelling of population and to strengthen the rural space to reduce regional imbalances at the individual level so that real development is achieved. Some of these questions on migration have been posed in this paper to take up further to promote policy formations and to organise the migrant manpower for a better India.Views expressed in this paper are personal and have no relations with Government and the organisation of author's affiliation in any way. 相似文献
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潜在震源区概念的界定 总被引:6,自引:0,他引:6
本文首先论述了地震危险性概率分析方法中潜在震源区的概念及其地位和作用,在此基础上,比较了它与地震危险区的差异,其次,阐述了我国现行地震危险性概率分析方法对潜在震源区概念的发展,最后,讨论了潜在震源区的不确定性问题。 相似文献
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地震危险性评判,通常需要将多种方法的结果加以综合。为了去除各种方法中可能的重复信息,并对各种方法对危险性评判结论的重要程度进行合理的度量,使综合的结果更加合理,我们引入了分量分析方法。本文首先介绍了分量分析方法的基本原理,其次阐述了该方法在地震危险性综合评判中的应用,最后给出了华北北部中长期地震危险性预测的一个计算实例。 相似文献
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