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971.
介绍了以活性污泥 1号模型 (ASM1 )和固体通量沉淀模型为基础 ,结合反应器原理 ,用VB6 .0计算机语言建立A/O法活性污泥模拟器的方法 ,探讨了A/O法活性污泥系统的模拟工艺流程、各组分的物料平衡关系和欧拉法数值积分的步长选取等问题。模拟器的校准结果表明 ,该模拟器建立的思路和方法完全正确 ,可以用于A/O法活性污泥系统的模拟和预测。  相似文献   
972.
活性污泥处理系统的计算机模拟   总被引:5,自引:0,他引:5  
介绍了以活性污泥1号模型(ASMI)和固体通量沉淀模型为基础.结合反应器原理.用VB6.0计算机语言建立城市污水活性污泥模拟器的方法,探讨了生物反应器和二沉池的模拟工艺流程、各组分的物料平衡关系和欧拉法数值积分的步长选取等问题。模拟器的校准结果表明,该模拟器建立的思路和方法是可靠的.可以用于城市污水生物处理系统的模拟和预测。  相似文献   
973.
Summary In all the species of theCataglyphis bicolor group examined yet, i.e.C. bicolor, C. diehli, C. isis, C. nodus, andC. viaticus, 2-methyl-1-hexanol is the characteristic substance and almost the only substance found in the mandibular glands. Its chirality has been determined inC. bicolor and shown to be exclusively (S)-2-methyl-1-hexanol.  相似文献   
974.
刘学玲 《环境与发展》2020,(4):138-138,140
本文使用碱性过硫酸钾消解紫外分光光度法(HJ636-2012)和流动注射-盐酸萘乙二胺分光光度法(HJ668-2013)2种方法对地表水总氮进行对比分析测试,结果显示:流动注射-盐酸萘乙二胺分光光度法测定结果小于碱性过硫酸钾消解紫外分光光度法的测定值。同时对该结果进行了原因分析,为地表水总氮测定方法的选择具有参考价值。  相似文献   
975.
以分频最大振级(VL max)和最大Z振级(VL Z max)作为评价量,结合相关标准,监测与评价北京市地铁列车运行引起的临近建筑室内振动。结果表明:北京市2条地铁线路的振动特征频率分别为25 Hz、31.5 Hz、40 Hz和63 Hz,以40 Hz为主;特征频率上振动加速度级(VAL)增量明显;VL max、VL Z max的大小既与频率计权因子不统一有关,也与地铁对建筑室内振动的影响程度及振动能量在不同中心频率上的分布差异直接相关;地铁隧道埋深较水平距离对地铁振动衰减作用显著;地铁振动监测与评价的频率范围可统一为对人体影响较大的1 Hz^80 Hz,并统一频率计权因子。  相似文献   
976.
The objectives of the study were to determine the aflatoxin M1 content in human milk samples in Vojvodina, Serbia, and to assess the risk of infants' exposure to aflatoxins food contamination. The growth of Aspergillus flavus and production of aflatoxin B1 in corn samples resulted in higher concentrations of AFM1 in milk and dairy products in 2013, indicating higher concentrations of AFM1 in human milk samples in 2013 and 2014 in Serbia. A total number of 60 samples of human milk (colostrum and breast milk collected 4–8 months after delivery) were analyzed for the presence of AFM1 using the Enzyme Linked Immunosorbent Assay method. The estimated daily intake of AFM1 through breastfeeding was calculated for the colostrum samples using an average intake of 60 mL/kg body weight (b.w.)/day on the third day of lactation. All breast milk collected 4–8 months after delivery and 36.4% of colostrum samples were contaminated with AFM1. The greatest percentage of contaminated colostrum (85%) and all samples of breast milk collected 4–8 months after delivery had AFM1 concentration above maximum allowable concentration according to the Regulation on health safety of dietetic products. The mean daily intake of AFM1 in colostrum was 2.65 ng/kg bw/day. Results of our study indicate the high risk of infants' exposure, who are at the early stage of development and vulnerable to toxic contaminants.  相似文献   
977.
The role of religious factors in the disaster experience has been under‐investigated. This is despite evidence of their influence throughout the disaster cycle, including: the way in which the event is interpreted; how the community recovers; and the strategies implemented to reduce future risk. This qualitative study examined the role of faith in the disaster experience of four faith communities in the Hawaiian Islands of the United States. Twenty‐six individuals from the Bahá'í, Buddhist, Church of Jesus Christ of Latter‐day Saints (LDS), and United Methodist Church communities participated, including 10 faith leaders and 16 laypersons. The results suggest that religious narratives provide a framework for interpretation of, preparedness for, and responses to disasters. Preparedness varied widely across faith communities, with the LDS community reporting greater levels of preparedness than other communities. Recommendations include the development of collaborative efforts between disaster managers and faith leaders to increase preparedness within faith communities, which may facilitate community‐wide disaster risk reduction.  相似文献   
978.
Political transitions often trigger substantial environmental changes. In particular, deforestation can result from the complex interplay among the components of a system—actors, institutions, and existing policies—adapting to new opportunities. A dynamic conceptual map of system components is particularly useful for systems in which multiple actors, each with different worldviews and motivations, may be simultaneously trying to alter different facets of the system, unaware of the impacts on other components. In Myanmar, a global biodiversity hotspot with the largest forest area in mainland Southeast Asia, ongoing political and economic reforms are likely to change the dynamics of deforestation drivers. A fundamental conceptual map of these dynamics is therefore a prerequisite for interventions to reduce deforestation. We used a system‐dynamics approach and causal‐network analysis to determine the proximate causes and underlying drivers of forest loss and degradation in Myanmar from 1995 to 2016 and to articulate the linkages among them. Proximate causes included infrastructure development, timber extraction, and agricultural expansion. These were stimulated primarily by formal agricultural, logging, mining, and hydropower concessions and economic investment and social issues relating to civil war and land tenure. Reform of land laws, the link between natural resource extraction and civil war, and the allocation of agricultural concessions will influence the extent of future forest loss and degradation in Myanmar. The causal‐network analysis identified priority areas for policy interventions, for example, creating a public registry of land‐concession holders to deter corruption in concession allocation. We recommend application of this analytical approach to other countries, particularly those undergoing political transition, to inform policy interventions to reduce forest loss and degradation.  相似文献   
979.
溶剂萃取法是目前回收处理含高浓度对硝基酚废水的有效方法.选用QH-1为萃取剂,采用HL离心萃取器对含对硝基酚废水的处理进行了实验研究.实验结果表明,对于对硝基酚硝酸溶液-QH-1体系,对硝基酚的分配比是1103.4,用Φ20 mm HL离心萃取器处理对硝基酚废水时,在合适的操作条件下,单级传质级效率E和三级串联萃取率ρ都可达99%以上,三级串联的反萃率也可达98%以上.  相似文献   
980.
儿童肺功能指标测量方法比较及异常值的探讨   总被引:1,自引:0,他引:1  
比较了儿童肺功能机读数据与人工手测数据 ,并应用统计学原理探讨了适合于研究空气污染暴露与儿童肺功能健康关系的 FVC实测值 /预计值 (% )、FEV1 实测值 /预计值 (% )、FEV1 /FVC(% )这三种肺功能指标的异常值分界线。得出 FVC或 FEV1 实测值 /预计值 (% )的异常值范围为 <85% ,FEV1 /FVC(% )的异常值范围为 <80 %  相似文献   
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