基于BPA对配电网无功优化的研究

对配电网无功优化中的补偿设备安装位置和补偿容量进行了研究,首先介绍了无功功率补偿的原则和方法,然后对配电网4种补偿方案进行了详细分析和对比,认为:对功率因数较低的变电站及线路应采用配电线路固定补偿方案.以河北南网某县级电网为算例,使用潮流计算软件BPA(Bonneville Power Administration)无...     

BPA向PSCAD模型转换的研究

电力系统电磁暂态仿真是测试继电保护装置性能的重要手段,也是分析交直流混合输电系统可靠性的重要方法.目前国内对电网动态仿真大都是对机电暂态过程的仿真,故电网数据也按照机电暂态仿真软件数据格式存储,从而造成了电磁暂态仿真数据的匮乏.在详细分析了机电暂态仿真软件BPA与电磁暂态仿真软件PSCAD差别的基础上,介绍了一种BPA向PSCAD的自动模型转换的实现方法,为电力系统电磁暂态仿真提供可靠的数据支撑,并且通过算例在2种软件下的电气拓扑结构和动态特性的比较,验证该转换方法的有效性和准确性.     

基于灰色关联证据的多源故障信息融合方法及其应用

针对大型设备故障诊断中特征量表现出来的不确定性和非精确性,提出了一种基于灰色关联理论来获取基本概率测度（BPA）的方法。该方法确定各故障特征量的参考样本,然后根据灰色相关性理论求得待诊断样本的相关系数,所取得的相关系数进行归一化处理即得到BPA值,经过Dempster多源组合规则进行多证据融合,得到最后的诊断结果。将所提方法用于电机转子故障诊断,实验结果表明该方法有效。     

Analytical determination of bisphenol A (BPA) and bisphenol analogues in paper products by LC-MS/MS

ABSTRACT

In this study a sensitive analytical method based on liquid chromatography-electrospray tandem mass spectrometry (LC-MS/MS) was developed for the simultaneous analysis of bisphenol A (BPA), bisphenol AF (BPAF), bisphenol B (BPB), bisphenol E (BPE), bisphenol F (BPF) and bisphenol S in different paper and board products, including virgin fibre samples and recycled samples. Analytes were extracted from the paper matrix using a simple solvent extraction and chromatographic separation was performed on a C18 core-shell (100 mm x 2.1 mm i.d.; 1.7 µm particle size) column. The developed method showed good linearity (R² > 0.9921) for all analytes. Absolute recoveries ranged from 71 to 115% and precision in terms of reproducibility and repeatability (intra- and inter-day) yielded in relative standard deviations (RSDs) of less than 15.0% and 17.4%, respectively. The limit of detection (LOD) and limit of quantification (LOQ) for the different analytes ranged from 0.29 to 0.40 µg kg^?1 paper and from 1.09 to 1.32 µg kg^?1 paper, being in the same range for all analytes. Quantitation of the analytes was performed using the internal standard procedure, with concentrations of < LOQ to 9599 µg kg^?1 for the different analytes. Furthermore, a calculation of the maximum migration, assuming the ‘worst case’ scenario of 100% migration was performed.     

Determinging BPA under uncertainty environments and its application in data fusion

Dempster-Shafer (DS) theory of evidence has been widely used in many data fusion application systems. However, how to determine basic probability assignment, which is the main and the first step in evidence theory, is still an open issue. In this paper, a new method to obtain Basic Probability Assignment (BPA) is proposed based on the similarity measure between generalized fuzzy numbers. In the proposed method, species model can be constructed by determination of the min, average and max value to construct a fuzzy number. Then, a new Radius Of Gravity (ROG) method to determine the similarity measure between generalized fuzzy numbers is used to calculate the BPA functions of each instance. Finally, the efficiency of the proposed method is illustrated by the classification of Iris data.     

A composite objective metric and its application to multi-focus image fusion

The research is motivated by the conclusion that single metric can’t give the best assessment in all situations. In this paper, a new method for objective no-reference (NR) image quality assessment (IQA) with multi-metric combination (MMC) is presented, and has four characteristics: 1) It is a NR assessment applicable for arbitrary multi-focus images; 2) The metric-selection based on segmentation consistency is effective to process various multi-focus images. 3) The linear and nonlinear conversion functions are constructed respectively to transform each pair of selected metrics into a set of basic probability assignment (BPA). 4) D-S evidence theory is introduced to exploit the advantage of performance evaluation and explore a resolution to the conflicting circumstance. Experiments conducted with five sets of multi-focus images confirm the effectiveness and robustness of our metric in contrast with single metric.     

基于D-S证据理论的预警卫星探测效能评估方法

为减少预警探测卫星探测效能评估中的不确定性,弥补模糊层次分析法等传统评估方法在处理不确定问题上的不足,提出了一种基于D-S证据理论(Dempster-Shafer证据理论)的效能评估方法.该方法将评估指标和评估信息看作是D-S证据理论中的焦元和证据源,再利用Dempster聚合规则进行聚合.结果表明:此方法比传统的模糊AHP法具有更强的处理不确定性信息的能力,可以提高评估的精度.     

石墨烯改性环氧树脂过程中快速纯化功能化石墨烯的方法

利用电荷平衡原理,在功能化石墨烯改性环氧树脂的过程中,设计了一种通过添加少量电解质溶液破坏功能化石墨烯体系的电荷平衡,以加速功能化氧化石墨烯的沉降速率,从而在低速离心条件下快速去除双酚A(BPA)功能化石墨烯(BPA-GO)中存在的过量BPA的方法。同时,采用传统的透析法与之进行对比实验,选用红外光谱仪、紫外-可见分光光度计对两种方法的纯化效果进行了分析,且采用离心分离法探讨了转速对所提方法分离效果的影响。结果表明,所提出的纯化方法对样品的结构没有产生影响,且所提方法相比于传统的透析法,不仅纯化效率较高、效果较好、对设备要求较低,而且具有适用于工业化生产的优点。     

双酚S影响3T3-L1前脂肪细胞分化及其作用机制的研究

双酚A(BPA)的内分泌干扰作用以及对人体产生的不良影响,使双酚S(BPS)作为替代品在食品包装材料中应用更加广泛。BPS在大规模应用之前,并没有对其安全性进行充分研究。本文以3T3-L1前脂肪细胞为体外模型,探究BPS对3T3-L1前细胞分化的影响及作用途径,评价BPS安全性的同时,也为肥胖等慢性代谢疾病的预防提供参考。研究结果表明:BPS能促进3T3-L1前脂肪细胞生长,当浓度超过400μmol/L时,才能显著抑制细胞的增殖;BPS能显著诱导分化的3T3-L1细胞内脂质的积累,并呈现非剂量依赖关系;与模型组相比,BPA上调PPARγ、C/EBR和aP2基因的表达,而BPS只作用PPARγ基因的过表达,BPS和BPA都能使GLUT4基因的表达显著下降(p0.01)。总之BPS和BPA作用脂肪细胞分化的途径不完全一样,可能是在多种转录因子的共同作用下完成的。     

应用于EMS高级应用系统的BPA程序快速调用方法与接口设计

针对电网EMS系统中各个高级应用模块在调用BPA暂态计算程序时出现的接口程序继承性差、接口程序调用效率低下的不足,提出了一种快速有效调用BPA暂态计算程序的接口设计方法。通过设定统一的BPA暂态计算程序接口调用模式和文件交互标准,解决了BPA暂态计算程序接口继承性差的问题。同时,根据EMS高级应用调用BPA暂态计算程序的特点,设计了一种快速调用BPA暂态计算程序的接口设计方法,实现了BPA暂态计算程序的快速调用。利用精细规则自动发现系统在广东省电网调用BPA暂态计算程序的算例测试表明:该接口程序能够提供继承性强的BPA暂态计算程序的接口程序,并且可以实现BPA暂态计算程序的快速调用。