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221.
To analyze the impact of the related economic factors on China's energy demand, Path analysis is used to analyze the major factors and their direct and indirect effects on energy demand. This study showed that the main factors that affect the energy demand are the economic growth, the total population, and the primary energy structure, the economic growth is the main determining factor, and the primary energy structure is the major restrictive factor. On this basis and considering the multicollinearity and the validity of the forecast, we established a partial least-square (PLS) and the trend extrapolation prediction model, and then we sum up all the information to found a PLS—trend extrapolation combination forecasting model based on the optimized combining forecast theory. Finally, we obtain the probability distribution of the error using the Bayesian statistic theory and find the confidence interval of combining forecasting result. The results indicate that the outcome of combining forecasting will be more precise after using the Bayesian error correction approach. 相似文献
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Lin Li Jiawei M Kaixiong Yang Fengguang Chai Junxin Liu Xuesong Guo 《环境科学学报(英文版)》2021,33(10):120-133
Landfill sites are regarded as prominent sources of bioaerosols for the surrounding atmosphere. The present study focused on the emission of airborne bacteria and fungi in four seasons of a sanitary landfill site. The main species found in bioaerosols were assayed using high-throughput sequencing. The SourceTracker method was utilized to identify the sources of the bioaerosols present at the boundary of the landfill site. Furthermore, the health consequences of the exposure to bioaerosols were evaluated based on the average daily dose rates. Results showed that the concentrations of airborne bacteria in the operation area (OPA) and the leakage treatment area (LTA) were in the range of (4684 ± 477)–(10883 ± 1395) CFU/m3 and (3179 ± 453)–(9051 ± 738) CFU/m3, respectively. The average emission levels of fungal aerosols were 4026 CFU/m3 for OPA and 1295 CFU/m3 for LTA. The landfill site received the maximum bioaerosol load during summer and the minimum during winter. Approximately 41.39%– 86.24% of the airborne bacteria had a particle size of 1.1 to 4.7 µm, whereas 48.27%– 66.45% of the airborne fungi had a particle size of more than 4.7 µm. Bacillus sp., Brevibacillus sp., and Paenibacillus sp. were abundant in the bacterial population, whereas Penicillium sp. and Aspergillus sp. dominated the fungal population. Bioaerosols released from the working area and treatment of leachate were the two main sources that emerged in the surrounding air of the landfill site boundary. The exposure risks during summer and autumn were higher than those in spring and winter. 相似文献
224.
Some minimum design requirements for landfill liner systems were compared, and the performance of several Japanese liner
systems was investigated by two-dimensional (2D) contaminant transport analysis. We demonstrate that (1) the performance of
each system specified by the Japanese Ministry of Health and Welfare (at present the Ministry of Health, Labor, and Welfare)
varies, (2) the adsorption characteristics of the mineral barrier has a significant effect on the contaminant transport process,
and (3) a geomembrane layer in the barrier system is very efficient in reducing the peak concentration of contaminants in
the groundwater beneath a landfill even if the geomembrane has a number of defects. Under the conditions considered, the analysis
results show that a liner system without a geomembrane layer should be avoided.
Received: July 4, 2001 / Accepted: March 26, 2002 相似文献
225.
地理信息系统在环境影响评价中的应用 总被引:4,自引:0,他引:4
从项目环境影响评价(EIA)的局限性出发,简述了目前EIA的研究现状,同时概述了地理信息系统(GIS)的功能和应用,重点讨论了环境影响评价领域中应用地理信息系统的现状、必要性及其展望。 相似文献
226.
以某污水厂的氧化沟污泥和剩余污泥为培养对象,获得了SRB占优的厌氧污泥,分析了活性污泥厌氧驯化过程中微生物的分布规律,考察了不同种类SRB污泥固定化小球处理水中硫酸根、锌及镉的效果.结果表明:pH6.0~7.0,温度35℃,硫酸盐浓度4g/L,时间在24h时,剩余污泥固定化小球处理含Zn(II)400mg/L的废水,去除率达到100%,氧化沟污泥固定化小球Zn(II)的去除率为90%左右;对500mg/L含镉废水,剩余污泥固定化小球8h能去除水中95?(II),氧化沟污泥固定化小球对Cd(II)的去除率为80%.硫酸盐还原菌污泥固定化技术中剩余污泥优于氧化沟污泥. 相似文献
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酸雨对汉白玉的危害研究 总被引:1,自引:0,他引:1
采用模拟的方法研究了酸雨对天然汉白玉危害,研究结果表明,酸雨对汉白玉石材的危害主要是溶解腐蚀。根据数量统计获得了影氧化钙损失的因素和腐蚀速率“b”以及腐蚀的规律。 相似文献
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内凸筋口琴管,是汽车空调的一种新型散热管.具有散热效果好、单位面积小、重.量轻等优点.此文介绍了连续挤压内凸筋口琴管模具的设计方法及其模具芯头的冷挤压加工. 相似文献