建筑室内人员污染源散发特性与有效散发模型

基于典型人员污染物指标的散发机制与特点并结合中国人员体型特征数据分析了年龄、性别、活动水平对人员污染源散发的影响关系,同时通过借助不稳定性系数给出了由人体气味污染不稳定性因素作用引起的CO2减少量的确定方法,并根据其与人体CO2产生量之间的叠加关系建立了人员污染源有效散发量的计算模型。研究结果表明,中国男性与女性的CO2散发水平存在差异,并且人体CO2散发水平随活动强度的变化率与年龄、性别有关;此外,人体气味污染不稳定性因素对CO2减少率的影响程度随通风换气次数、人员污染源作用时间的变化关系存在显著变化阶段和相对稳定阶段。     

Anti-inflammatory effects and mechanisms of usnic acid

The anti-inflammatory effect and mechanism of Usnic acid (UA) were explored on lipopoly-saccharide (LPS)-stimulated RAW264.7 cell line.The effects of UA on pro-inflammatory cytokines including tumor necrosis factor-alfa (TNF-α),interleukin-6 (IL-6) and interleukin-1 beta (IL-1β),pro-inflammatory mediators such as nitric oxide (NO),inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) were studied by sandwich ELISA,real-time PCR and western blot analyses.Similarly,the effect of UA on anti-inflammatory cytokine interleukin-10 (IL-10) and anti-inflammatory mediator heme oxygenase-1 (HO-1) were also studied following the same methods.Furthermore,nuclear factor-κB (NF-κB) was assayed by immunocytochemistry.The results showed that UA has anti-inflammatory effect by down-regulatinng iNOS,COX-2,IL-1β,IL-6 and TNF-α,COX-2 gene expression through the suppression of NF-κB activation and increasing anti-inflammatory cytokine IL-10 and anti-inflammatory mediator HO-1 production.     

A GEP-based spatial decision support system for multisite land use allocation

Multisite Land Use Allocation Problem (MLUA) refers to the problem of allocating more than one land use type in an area. MLUA problem is one of the truly NP Complete (combinatorial optimization) problems. To cope with this type of problems, intelligent techniques such as genetic algorithms, and simulated annealing, have been used. Research in the area of Spatial Decision Support Systems (SDSS) for resource allocation issues, a new scientific area of information system applications developed to support semi-structured or unstructured spatial decisions, has recently generated attention for integrating Artificial Intelligence (AI) techniques with Geographic Information Systems (GIS). In this paper we demonstrate how GIS can be integrated with Gene Expression Programming (GEP), a recently developed AI approach, for solving MLUA problems. The feasibility of the proposed approach in solving MLUA problems was checked using a fictive case study. The results indicated that the proposed approach gives good and satisfactory results.     

Uncooled InAs0.09Sb0.91 photoconductors with cutoff wave- length extended to 11.5 μm

Uncooled InAsSb photoconductors were fabricated. The photoconductors were based on InAs0.05Sb0.95 and InAs0.09Sb0.91 thick epilayers grown on InAs substrates by melt epitaxy (ME). Ge immersion lenses were set on the photoconductors. The cutoff wavelength of InAs0.09Sb0.91 detectors is obviously extended to 11.5 mm, and that of InAs0.05Sb0.95 detectors is 8.3 mm. At room temperature, the peak detectivity of Dλp at wavelength of 6.8 mm and modulation frequency of 1 200 Hz is 1.08×109 cm.Hz1/2.W-1 for InAs0.09Sb0.91 photoconductors, the detectivity D at wavelength of 9 mm is 7.56×108 cm.Hz1/2.W-1, and that at 11 mm is 3.92×108 cm.Hz1/2.W-1. The detectivity of InAs0.09Sb0.91 detectors at the wavelengths longer than 9 mm is about one order of magnitude higher than that of InAs0.05Sb0.95 detectors, which rises from the increase of arsenic (As) composition in InAs0.09Sb0.91 materials.     

压缩感知理论在谐波检测中的运用

运用传统的奈奎斯特定理对电力系统中的谐波信号进行采样将会产生极其庞大的数据量,而全新的压缩感知理论突破了传统采样定理的限制,在信号满足稀疏性的前提下,只需要较少的数据就可以实现信号的重构。文中在对现有的贪婪匹配追踪和自适应算法分析总结的基础之上,结合谐波信号自身的特点,提出了一种新的稀疏度自适应压缩采样匹配追踪算法。此算法可在信号稀疏度未知的情况下,通过信号代理和回溯的思想自适应调节步长逐步逼近原始信号,从而实现以较少采样数据进行谐波检测的目标。MATLAB中的仿真实验表明,运用所提出的算法进行谐波检测的效果理想。     

基于自适应滑模层极值搜索的光伏发电最大功率跟踪方法

保证光伏阵列快速到达最大功率点并且能稳定运行,一直以来是光伏发电研究领域关注的重要问题之一。为此,文中提出了基于参数自适应调整滑模层极值搜索控制的光伏发电系统最大功率跟踪新方法。首先证明了基于滑模极值搜索的光伏发电系统最大功率跟踪控制策略的稳定性;然后提出采用具有更低控制频率及更低控制噪声的滑模层函数代替简单的开关函数。在此基础上,进一步提出了控制参数的自适应调整方法,使得控制系统在具有较好的控制品质的同时,避免了繁琐的人为参数调整。算例证明了所提方法的有效性。     

基于Ansys的电磁系统温度场仿真技术研究

电磁系统的发热是带来控制与保护开关电器温升的主要因素,对其电磁系统进行了温度场仿真。对电磁系统各部分的发热做了分析计算,同时试验测量了在主回路不通电情况下电磁系统各部分的温度,与仿真结果进行比较,验证理论和仿真分析的正确性。     

基于AMESim的燃料电池系统低温起动仿真

当前燃料电池汽车受到越来越多的关注,而燃料电池汽车商业化前还有很多问题亟需解决,其中燃料电池系统低温起动便是一个重点难题。使用AMESim软件建立了一个燃料电池一维系统模型,针对燃料电池系统恒电压和恒电流低温起动过程进行了研究。研究发现,较低的起动电压和较高的起动电流更有利于低温起动过程,且恒电压起动比恒电流起动更具优势。     

电力定制服务概念及国内外实践现状

满足电力客户对供电品质和服务的期望,对保障市场下供电企业的可持续发展和竞争力具有重要的意义。在分析供电企业面临挑战的基础上,首先从电力定制和定制服务2个角度阐述了电力定制服务的内涵,然后总结了国内外电力定制和定制服务的实践现状,最后讨论并指出了电力定制服务尚需解决的若干关键问题。