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841.
接种物浓度和负荷对餐厨垃圾消化性能及产气动力学的影响 总被引:1,自引:0,他引:1
为探析接种物浓度(Biomass concentration,BC)和负荷(Organic loading rate,OLR)对餐厨垃圾厌氧消化性能及产气动力学的影响,在中温批次厌氧消化反应器中进行BC和OLR梯度试验,采用理化分析探析各反应器的性能参数,并采用一阶模型和modified Gompertze模型评价各反应器的产气动力学特征.试验结果表明,超负荷会降低反应器运行效率,影响过程稳定性,而提高BC可以减少单位细胞承受的有机负荷,有利于优化厌氧消化过程.产甲烷阶段是餐厨垃圾厌氧消化的限速步骤,各实验条件下水解速率常数(k)始终大于产甲烷速率常数(R_m').OLR和BC对k和R_m'的影响是波动的,从两个参数的数值上无法判断反应器的稳定性.相比之下,高效运行的反应器k/R_m'保持在(2.54±0.62),k/R_m'随OLR的增加及BC的下降单调递增,而随着k/R_m'增加,反应器运行效率下降.这从反应动力学上证实了增加OLR会加剧产酸和耗酸过程的不匹配,引起反应器失稳;而提高的BC浓度有利于缓解这种失衡,对保证反应器的过程稳定具有重要意义. 相似文献
842.
以排水集团运行的几座污水处理厂为研究对象,对工艺设计参数及运行条件等进行对比分析,找出影响污泥膨胀的关键因素。采用微生物形态学和分子生物学方法对丝状菌种类进行辨别,确定研究的污水厂污泥膨胀的丝状菌主要为微丝(Microthrix parvicella)菌。通过分析微丝菌的特性,结合倒置A~2/O工艺的运行特点,在不进行任何改造的情况下,提出冬季运行将倒置A~2/O工艺调整为A/O工艺的运行措施。并将这一措施用于实际水厂,连续3年未发生污泥膨胀,污泥沉降性能较好,出水水质稳定。通过小试研究和实际水厂分析,证明厌氧选择器在控制污泥膨胀中可发挥一定作用,为活性污泥工艺设计提供参考。 相似文献
843.
We examined the antecedents and consequences of group potency in 71 multinational project teams in the Greater China region. We extended the theoretical basis of group potency by employing group identification theory. Results showed that group identification was one of the key factors in developing group potency. Further, fostering the acceptance of group goals that are interdependent was important for increasing group identification. We discuss the implications of our findings for future research. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
844.
Ernest H. O'Boyle Jr. Ronald H. Humphrey Jeffrey M. Pollack Thomas H. Hawver Paul A. Story 《组织行为杂志》2011,32(5):788-818
This meta‐analysis builds upon a previous meta‐analysis by (1) including 65 per cent more studies that have over twice the sample size to estimate the relationships between emotional intelligence (EI) and job performance; (2) using more current meta‐analytical studies for estimates of relationships among personality variables and for cognitive ability and job performance; (3) using the three‐stream approach for classifying EI research; (4) performing tests for differences among streams of EI research and their relationships with personality and cognitive intelligence; (5) using latest statistical procedures such as dominance analysis; and (6) testing for publication bias. We classified EI studies into three streams: (1) ability‐based models that use objective test items; (2) self‐report or peer‐report measures based on the four‐branch model of EI; and (3) “mixed models” of emotional competencies. The three streams have corrected correlations ranging from 0.24 to 0.30 with job performance. The three streams correlated differently with cognitive ability and with neuroticism, extraversion, openness, agreeableness, and conscientiousness. Streams 2 and 3 have the largest incremental validity beyond cognitive ability and the Five Factor Model (FFM). Dominance analysis demonstrated that all three streams of EI exhibited substantial relative importance in the presence of FFM and intelligence when predicting job performance. Publication bias had negligible influence on observed effect sizes. The results support the overall validity of EI. Copyright © 2010 John Wiley & Sons, Ltd. Note: Correction added on 22 July 2010 after first publication online on 29 June 2010. The affiliations for Ronald H. Humphrey and Thomas H. Hawver have been corrected in this version of the article. 相似文献
845.
Simone ManfrediDavide Tonini Thomas H. Christensen 《Resources, Conservation and Recycling》2011,55(11):995-1004
Several alternatives exist for handling of individual waste fractions, including recycling, incineration and landfilling. From an environmental point of view, the latter is commonly considered as the least desirable option. Many studies based on life-cycle assessment (LCA) highlight the environmental benefits offered by incineration and especially by recycling. However, the landfilling option is often approached unjustly in these studies, maybe disregarding the remarkable technological improvements that landfills have undergone in the last decades in many parts of the world.This study, by means of LCA-modelling, aims at comparing the environmental performance of three major management options (landfilling, recycling and incineration or composting) for a number of individual waste fractions. The landfilling option is here approached comprehensively, accounting for all technical and environmental factors involved, including energy generation from landfill gas and storage of biogenic carbon. Leachate and gas emissions associated to each individual waste fraction have been estimated by means of a mathematical modelling. This approach towards landfilling emissions allows for a more precise quantification of the landfill impacts when comparing management options for selected waste fractions.Results from the life-cycle impact assessment (LCIA) show that the environmental performance estimated for landfilling with energy recovery of the fractions “organics” and “recyclable paper” is comparable with composting (for “organics”) and incineration (for “recyclable paper”). This however requires high degree of control over gas and leachate emissions, high gas collection efficiency and extensive gas utilization at the landfill. For the other waste fractions, recycling and incineration are favourable, although specific emissions of a variety of toxic compounds (VOCs, PAHs, NOx, heavy metals, etc.) may significantly worsen their environmental performance. 相似文献
846.
847.
随着国家经济的飞速发展,减少作业人员在事故发生时所受到的职业危害尤为重要。本文对紧急冲淋设备的技术性能、作用进行了一定探讨与描述,希望对企业正确的配备紧急冲淋设备有所帮助。 相似文献
848.
介绍了功能共振理论,说明了事故发生机理,描述了功能单位,介绍了一般性能条件和功能性能波动状态,以及功能共振事故模型分析步骤。利用功能共振事故模型对可控飞行撞地事故进行了分析,识别描述了功能单位,建立了功能网络;根据一般性能条件评价了各个功能单位性能波动状态,在评价结果基础上分析了各个功能单位性能波动状态,确定了"管制员发出下降指令"和"输入导航点信息"两个随机状态功能单位;进一步分析了功能共振和失效功能连接,以及影响功能共振的功能因素,建立了功能共振失效网络,确定了"管制员发出下降指令"、"输入导航点信息"、"保持下降航路"、"到达指定导航点"四个功能共振单位;最后识别出了波动障碍,并制定了"调整飞行管理系统导航点信息显示方式"等多个性能监测措施管理可控飞行撞地功能性能波动。 相似文献
849.
为施工人员选择和配置安全可靠的个人防坠器,每年送到具有相应资质的检测单位进行强制检定,是防止高处坠落事故的重要手段。某型速差自控器在冲击试验中发生了钢丝绳断裂事故,为了查找和分析事故的真正原因,对不同厂家的速差自控器抽样,在相同试验方法和检测条件下进行冲击试验,并根据相关的标准对试验结果进行力学性能对比分析研究,找到了造成钢丝绳断裂事故的主要原因是该类型速差自控器使用的钢丝绳直径偏细以及缺少内部或外部缓冲器,研究中还发现部分国内标准技术要求不够明确,制造、检测和使用方对速差自控器相关标准理解存在偏差,是造成本次事故的间接原因。针对现有的部分速差自控器产品存在的质量问题,并根据现行最新标准和实际工作条件,提出改进了的检测方法和防范措施,从源头上防范坠落事故。 相似文献
850.