应用神经网络决定电力系统暂态稳定切机控制规律

提出一种应用单隐层前向神经网络决定多机电力系统暂态稳定切机控制 规律的方法。分析了所选神经网络输出量与输入量之间的映射关系，并给 出了6机试例系统的结果。     

基于GA-FSVR的极端温度应力下智能电能表退化预测模型

针对极端温度应力下智能电能表退化情况难以准确预测的问题,以计量误差作为退化指标,提出一种基于融合核支持向量回归(FSVR)与遗传算法(GA)的智能电能表退化预测模型。为了兼顾预测模型的学习与泛化能力,在传统单核支持向量回归模型的基础上,提出一种基于RBF核与Sigmoid核的新的融合核函数,并进一步建立基于融合核函数的FSVR模型,预测极端温度应力作用下智能电能表的退化过程;在FSVR模型参数调节阶段,通过GA对核参数进行优化,提高模型预测精度。采用某批次智能电能表分别在高温(50℃)、低温(-40℃)两组极端温度应力下连续14个月的实际退化测试数据展开比较实验,结果表明提出的预测模型能准确追踪不同极端温度下智能电能表的退化趋势,可为我国典型地区的智能电能表可靠性分析提供指导。     

Fuzzy对称可实现矩阵容度的计算

本文讨论了 Fuzzy 对称可实现矩阵的容度问题。找出了可计算的一个下界估计,借助于文〔8〕和文〔9〕提出的Ⅱ型 Fuzzy 关系不定方程的求解,给出了计算容度和计算相应的一组实现矩阵的算法。     

覆盖型岩溶区地面塌陷的两种力学分析模型及其应用

以地面塌陷的地质模式为基础,建立了覆盖型岩溶区地面塌陷的两种力学分析模型——整体垮塌型和土洞渐扩型;讨论了两者的力学形成机制,提出了稳定性分区原则。其分区原则与桂林地区塌陷的统计规律基本吻合。     

校长办公子系统

本文介绍了 SZU—MIS 校长办公子系统的组成、开发及应用。     

客车车身结构的随机应力分析

本文以BJ-633A型旅行车车身为研究对象,在海南试车场及一般公路上进行了动态测试,将获取的随机信号在CF-500频谱分析仪、SW-160和SD-142应力波分析仪上进行了数据处理,着重分析了该车以不同车速在各种道路上行驶时,车身结构动应力的随机特性以及对车身结构强度的影响。指出路面不平度和车速是强化车身结构可靠性试验的重要因素。     

Simultaneous synthesis of sub and above-ambient heat exchanger networks including expansion process based on an enhanced superstructure model

Synthesis of heat exchanger networks including expansion process is a complex task due to the involvement of both heat and work. A stream that expands through expanders can produce work and cold load, while expansion through valves barely affects heat integration. In addition, expansion through expanders at higher temperature produces more work, but consumes more hot utility. Therefore, there is a need to weigh work production and heat consumption. To this end, an enhanced stage-wise superstructure is proposed that involves synchronous optimization of expander/valve placement and heat integration for each pressure-change sub-stream in stages. A mixed-integer nonlinear programming (MINLP) model is established for synthesizing sub and aboveambient heat exchanger networks with multi-stream expansion, which explicitly considers the optimized selection of end-heaters and end-coolers to adjust temperature requirement. Our proposed method can commendably achieve the optimal selection of expanders and valves in a bid for minimizing exergy consumption and total annual cost. Four example studies are conducted with two distinct objective function (minimization of exergy consumption and total annual cost, respectively) to illustrate the feasibility and efficacy of the proposed method.     

适用于“一步酸溶法”生产氧化铝工艺中稀释料浆的高分子絮凝剂的合成

为达到"一步酸溶法"生产氧化铝工艺中稀释料浆在高温、高酸度工况下进行固液高效分离的目的,以丙烯酰胺(AM)与阳离子(DMDAAC)为共聚单体,通过水溶液聚合法合成了阳离子聚丙烯酰胺(CPAM)絮凝剂。以转化率和相对分子质量为目标,通过单因素分析法确定了最优的合成工艺条件,即反应温度30℃,单体总质量分数为30%,阳离子度5%,K2S2O8和NaHSO3质量分数均为0.005%,2,2′-偶氮二(2-脒基丙烷盐酸盐)(V50)质量分数为0.0025%,乙二胺四乙酸(EDTA)质量分数为0.05%的条件下,反应时间为6 h,获得相对分子质量为1.2×107溶解性能较好的阳离子型聚丙烯酰胺(CPAM)。     

Maternal Malnutrition Affects Hepatic Metabolism through Decreased Hepatic Taurine Levels and Changes in HNF4A Methylation

Fetal programming implies that the maternal diet during pregnancy affects the long-term health of offspring. Although maternal diet influences metabolic disorders and non-alcoholic fatty liver disease in offspring, the hepatic mechanisms related to metabolites are still unknown. Here, we investigated the maternal diet-related alterations in metabolites and the biological pathway in male offspring at three months of age. Pregnant rats were exposed to 50% food restriction during the prenatal period or a 45% high-fat diet during the prenatal and postnatal periods. The male offspring exposed to food restriction and high-fat diets had lower birth weights than controls, but had a catch-up growth spurt at three months of age. Hepatic taurine levels decreased in both groups compared to controls. The decreased hepatic taurine levels in offspring affected excessive lipid accumulation through changes in hepatocyte nuclear factor 4 A methylation. Moreover, the alteration of gluconeogenesis in offspring exposed to food restriction was observed to a similar extent as that of offspring exposed to a high fat diet. These results indicate that maternal diet affects the dysregulation in hepatic metabolism through changes in taurine levels and HNF4A methylation, and predisposes the offspring to Type 2 diabetes and non-alcoholic fatty liver disease in later life.     

Adsorption of benzoic acid by CTAB exchanged montmorillonite

This paper reports the adsorption of benzoic acid from water on cetyl trimethylammonium exchanged montmorillonite (CTAB-montmorillonite). Important factors are the adsorbent concentration, ionic strength, equilibrium time and pH. The largest adsorption is at pH 9. The adsorption kinetics data fitted the pseudo-second-order equation. The adsorption isotherms at different pH were linear indicating a partition mechanism. Up to about 61% of the dissolved benzoic acid was adsorbed by CTAB-montmorillonite. These results indicate that CTAB-montmorillonite is a potential adsorbent for benzoic acid.