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61.
全耦合活性污泥模型(FCASM3)Ⅰ:建模机理及数学表征 总被引:2,自引:0,他引:2
在充分分析活性污泥系统中生物反应机理的基础上,建立了活性污泥系统生物去除营养物质的细观机理模型--全耦合活性污泥模型(Fully Coupled Activated Sludge Model No.3,简称FCASM3).FCASM3将系统中微生物划分为8类菌群,包含31种组分、72个子过程;该模型的主要特点是将活性污泥系统中的微生物进一步细化,充分考虑了系统中微生物间的相互作用.FCASM3引入了硝化-反硝化过程中的中间产物亚硝酸盐.实现了对两步硝化-反硝化过程的模拟;FCASM3不仅包含聚糖菌的有关生物反应过程,而且还考虑了聚磷菌(非反硝化聚磷菌和反硝化聚磷菌)以及聚糖菌的厌氧维持过程,为直接体现温度对生物反应的影响,FCASM3将温度作为一个变量直接耦合到生物反应速率方程中. 相似文献
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63.
结合工程实际,介绍了太阳能产业用多晶硅片切割过程中产生的割液废液的处理工艺及回收工艺,并分析了它的投资成本和经济效益。 相似文献
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汞的毒性、环境行为、生物有效性不仅跟其浓度有关,还决定于其化学形态,因此汞的形态分析在环境科学中具有重要意义。样品前处理几乎是汞形态分析研究中不可或缺的步骤,而色谱和光谱/质谱联用技术是目前普遍采用的分离检测方法。文章对近十年来这些方面的研究进展进行了综述,主要包括样品的前处理方法如酸/碱溶剂萃取、微波辅助萃取、固相萃取、固相微萃取、单滴微萃取、分散液液微萃取等,以及色谱(液相色谱、气相色谱)和毛细管电泳与光谱/质谱(紫外可见光谱、原子吸收光谱、原子荧光光谱、等离子体质谱等)的联用技术在汞化合物形态分析中的应用情况。最后提出今后应重点研究建立高效、简便的前处理方法,发展高分离度、高灵敏度、高速度的分离检测联用技术,以便更好地对汞的形态进行分析监测。 相似文献
66.
P.K. Marhavilas D. Koulouriotis 《Journal of Loss Prevention in the Process Industries》2011,24(5):477-523
The objective of this work is to determine and study, analyze and elaborate, classify and categorize the main risk analysis and risk-assessment methods and techniques by reviewing the scientific literature. The paper consists of two parts: a) the investigation, presentation and elaboration of the main risk-assessment methodologies and b) the statistical analysis, classification, and comparative study of the corresponding scientific papers published by six representative scientific journals of Elsevier B.V. covering the decade 2000-2009. The scientific literature reviewing showed that the risk analysis and assessment techniques are classified into three main categories: (a) the qualitative, (b) the quantitative, and (c) the hybrid techniques (qualitative-quantitative, semi-quantitative). The qualitative techniques are based both on analytical estimation processes, and on the safety managers-engineers ability. According to quantitative techniques, the risk can be considered as a quantity, which can be estimated and expressed by a mathematical relation, under the help of real accidents’ data recorded in a work site. The hybrid techniques, present a great complexity due to their ad hoc character that prevents a wide spreading. The statistical analysis shows that the quantitative methods present the highest relative frequency (65.63%) while the qualitative a lower one (27.68%). Furthermore the hybrid methods remain constantly at a very low level (6.70%) during the entire processing period. 相似文献
67.
Two fundamental aspects of invasion dynamics are population growth and population spread. These quantities have been subject of study in biological invasions and can be used to study management and control of organisms. In this paper we derive formulae to calculate wave speed and rates of spread for coupled map lattices. Coupled map lattice models are dynamical models where space and time are discrete. We also show how wave speed and rate of spread can be calculated for structured population coupled map lattices in deterministic, stochastic environments and heterogeneous landscapes. Coupled map lattices are simple mathematical models that can be easily linked to landscape data to study invading organisms control strategies. 相似文献
68.
An optimized code for the near real-time retrieval of line of sight, temperature and volume-mixing ratio profiles of five key species (O3, H2O, HNO3, CH4 and N2O) from infrared limb spectra recorded by the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) experiment on board the ENVISAT-1 satellite was developed as part of an ESA-supported study. In this code line of sight and temperature are retrieved simultaneously among themselves, but sequentially with respect to the volume-mixing ratio of the five key species. The sequential retrieval leaves unaccounted the mapping of line of sight and temperature errors in the retrieved volume-mixing ratio of the constituents. This paper illustrates an algorithm that provides the a-posteriori evaluation of temperature and line-of-sight-induced error on the retrieved volume-mixing ratio of the MIPAS key species. It is shown that in most cases temperature and line-of-sight-induced error provides a significant contribution to the total volume-mixing ratio error. The variability of this error as a function of latitude, season and atmospheric model is also analyzed. 相似文献
69.
化学工程固沙在塔里木沙漠公路沙害防治中的适宜性 总被引:27,自引:0,他引:27
由于天然材料日益紧缺 ,研制适宜于流动性沙漠地区公路沙害防治的人工替代材料势在必行 .结合塔里木沙漠公路沙害环境 ,实验室优选出 L VA、LVP、WBS和 STB 4种抗性较好的固沙剂 ,对其理化性能、粘结体力学性能和抗风蚀性能等测试结果表明 :颗粒粒径 0.2μm~ 0.5μm,粘度 12 Pa·s~ 15Pa·s;10℃~70℃温度下无沉淀 ,不燃烧 ;实验抗压强度 1.0 MPa~12.1 MPa;10℃~-20℃低温下重量损失率 0%~ 1.8%;紫外光照射 300h强度损失率 0%~ 42%;在 5m·s-1~253m·s-1实验风速下 ,风蚀量 0g·(106cm2·h)-1~4.0 g·(106cm2·h)-1 ;现场试验固结层厚度 0.2 mm~0.5mm,强度高 .化学工程固沙技术适宜于塔里木沙漠公路沙害防治 . 相似文献
70.
Males of the Malaysian bushcricket species Mecopoda elongata synchronize or alternate their cyclically occurring song elements (chirps) in a duet. The acoustic interaction of males interacting in a duet was successfully simulated by means of mutually coupled song oscillators, which respond to a disturbance by a phase shift which is known from the phase response curves (PRCs) of real males. However, little is known about the acoustic interaction of males in a complex chorus situation. Therefore, the aim of the current study was to extend the duet model to a chorus taking into account an inhomogeneous spacing of agents and a natural variability of oscillator properties. This chorus model was used to study oscillator coupling in a chorus consisting of 15 agents. Since such a computer model allows one to simulate chorus manipulations that far exceed the possibilities of behaviour experiments, the following scenarios were simulated: modification of chorus density, sensory bias during sound production, selective attention to only a subset of neighbors and males joining or leaving a chorus. Simulation results allow one to draw conclusions about the chorusing behavior of males in a real chorus and about signaler and receiver aspects influencing chorusing formation and mate choice. 相似文献