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41.
本文介绍了一种新型的过滤技术(表面过滤技术)在袋式除尘器中的应用及其特点,该技术的采用可减少除尘器的压力损失,提高滤袋的使用寿命和除尘效率. 相似文献
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ThebufferingeffectsofaquaticsedimentsagainstacidicdepositionLiaoBohan;TangHongxiao(ResearehCenterforEco-EnvironmentalSciences... 相似文献
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Spatial variations in daily average CO2 concentrations above wetland surface of Xianghai National Nature Reserve, China 总被引:1,自引:0,他引:1
Horizontal and vertical variations of daily average CO2 concentration above the wetland surface were studied in Xianghai National Nature Reserve of China in August, 2000. The primary purpose was to study spatial distribution characteristics of CO2 concentration on the four levels of height(0.1 m, 0.6 m, 1.2 m and 2 m) and compare the differences of CO2 concentration under different land covers. Results showed that daily average CO2 concentration above wetland surface in Xianghai National Natural Reserve was lower than that above other wetlands in northeast China as well as the worldwide average, suggesting that Xianghai wetland absorbed CO2 in August and acted as“sink” of CO2. The horizontal variations on the four levels of height along the latitude were distinct, and had the changing tendency of“decreasing after increasing” with the increase of height. The areas with obvious variations were consistent on different levels of height,and those with the highest variations appeared above surface of shore, sloping field, Typha wetland and Phragmites wetland; the vertical variations were greatly different, with the higher variations in Phragmites wetland and Typha wetland, and the lands near the shore and the sloping field with the lower variations. Spatial variations of daily average CO2 concentrations above wet!and surface were affected by surface qualities and land covers. 相似文献
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Baisen Zhang Ian Valentine Peter D. Kemp 《Agriculture, ecosystems & environment》2005,110(3-4):279-288
Decision tree, one of the data mining approaches, was used to model the relative abundance of five functional groups of plant species, namely high fertility response grasses (HFRG), low fertility tolerance grasses (LFTG), legume, moss and flatweeds in a New Zealand hill-pasture ecosystem using aboveground biomass. The model outputs were integrated with a geographic information system (GIS) to map and validate the predictions on a pasture. The decision tree models clearly revealed the interactions between the functional groups and environmental and management factors, and also indicated the relative importance of these factors in influencing the functional group abundance. Soil Olsen P was the most significant factor influencing the abundance of LFTG and moss, while soil bulk density, slope and annual P fertiliser input were the most significant factors influencing the abundance of legume, HFRG and flatweeds, respectively. Generally, slope and soil Olsen P were the two key factors underlying the patterns of abundance for these five functional groups. For the five functional groups studied, there was an overall predictive accuracy of 75%. Modelling functional group abundance simplified the investigation of the complex interrelationship between species and environment in a pasture ecosystem. The integration of the decision tree with GIS in this study provides a platform to investigate community structure and functional composition for a pasture over space, and thus can be applied as a tool in pasture management. 相似文献
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矿区生态系统健康内涵及评价指标体系研究 总被引:1,自引:0,他引:1
结合生态系统健康理论及矿区发展特点,探讨了矿区生态系统健康内涵、阐述了矿区生态系统健康评价目的和评价指标体系的设置思想,构建了矿区生态系统健康评价指标体系。 相似文献
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本文根据石拐区实际,阐述了矿山开采造成的生态破坏与危害,分析了其产生原因,并以地面塌陷,煤矸石综合利用和生态恢复为重点,建立生态环境补偿机制为手段,建设生态经济为中心的生态恢复对策。 相似文献
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湖北银矿的开采实践证明,该矿主要矿体呈陡倾脉状,随着开采层次的深入,在矿区1 160m中段和1 110m中段的一些采场回采过程中,发现所采矿脉在纵向剖面上频繁出现"膝折".开始,由于对其认识不足,给采矿厂工作带来盲目性,并增加了难度.笔者通过对"膝折"规律的研究,分析矿区构造变形史,并探讨其形成机理,对采矿起到一定指导作用. 相似文献