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51.
活性污泥1#数学模型(ASM1)中的组分 总被引:1,自引:0,他引:1
活性污泥l#数学模型(AMl)常常用于预测污水处理厂中的生物过程。活性污泥数学模型组分的鉴定对活性污泥l#数学模型的应用具有重要的意义。本文描述了在活性污泥l#模型(ASMl)中污水组分的概念,以及组分鉴定的研究现状。 相似文献
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Nevin Akpinar İlkden Talay Coşkun Ceylan Sultan Gündüz 《Environment, Development and Sustainability》2004,6(4):473-486
As in many developing countries also in Turkey, agriculture is on the center of rural development and rural women are on the center of agriculture. Although they are main part as a major labor force at every stage of agricultural activity and undertake responsibilities such as domestic task and childcare, women do not profit from social and economic benefits proportionate to the responsibilities they have undertaken. Agrotourism is an alternative activity in the rural development process, which combines agriculture and tourism, improves natural resources, contributes the rural area socially and economically. The aim of this study is to examine the participation conditions of rural women to the agrotourism activities, which is considered as an option in the context of sustainable rural development, and to identify the possible social and economic implications of agrotourism on the rural women’s life, after determining the situation and importance of rural women in the agricultural activity. This research was carried out in three villages of Kalecik district of Ankara and data gathered from group meetings and surveys. 相似文献
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乐山市为全省核单位较多的地区之一.其环境陆地γ辐射剂量率、土壤、水体中放射性核素含量或元素浓度均接近于地区直水平.说明对环境无显著性影响. 相似文献
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Contrasting structure and composition of the understory in species-rich tropical rain forests 总被引:1,自引:0,他引:1
LaFrankie JV Ashton PS Chuyong GB Co L Condit R Davies SJ Foster R Hubbell SP Kenfack D Lagunzad D Losos EC Nor NS Tan S Thomas DW Valencia R Villa G 《Ecology》2006,87(9):2298-2305
In large samples of trees > or = 1 cm dbh (more than 1 million trees and 3000 species), in six lowland tropical forests on three continents, we assigned species with >30 individuals to one of six classes of stature at maturity (SAM). We then compared the proportional representation of understory trees (1-2 cm dbh) among these classes. The understory of the three Asian sites was predominantly composed of the saplings of large-canopy trees whereas the African and American sites were more richly stocked with trees of the smaller SAM classes. Differences in class representation were related to taxonomic families that were present exclusively in one continent or another. Families found in the Asian plots but not in the American plot (e.g., Dipterocarpaceae, Fagaceae) were predominantly species of the largest SAM classes, whereas families exclusive to the American plots (e.g., Melastomataceae sensu stricto, Piperaceae, and Malvaceae [Bombacacoidea]) were predominantly species of small classes. The African plot was similar to Asia in the absence of those American families rich in understory species, while similar to America in lacking the Asian families rich in canopy species. The numerous understory species of Africa were chiefly derived from families shared with Asia and/or America. The ratio of saplings (1-2 cm dbh) to conspecific canopy trees (>40 cm dbh) was lower in American plots than in the Asian plots. Possible explanations for these differences include phenology, moisture and soil fertility regimes, phyletic constraints, and the role of early successional plants in forest development. These results demonstrate that tropical forests that appear similar in tree number, basal area, and the family taxonomy of canopy trees nonetheless differ in ecological structure in ways that may impact the ecology of pollinators, dispersers, and herbivores and might reflect fundamental differences in canopy tree regeneration. 相似文献
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地震液化引起的地面大变形对桥梁桩基的影响研究综述 总被引:2,自引:0,他引:2
根据国内外文献资料,主要就地震高烈度区液化引起的地面侧向大变形对桥梁桩基的影响的研究现状进行分析,总结了地面大变形引起的震害情况、液化诱发地面大变形的机理及液化大变形的预测方法、桥梁桩基的震害和液化大变形对桥梁桩基的影响、桥梁桩基抗地面大变形的措施,以及存在问题和研究思路。 相似文献
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