工程方案选择的权重-属性决策分析方法

工程方案的选择是工程项目的战略决策问题 .从认知学原理出发 ,提出方案选择决策的 3个要素 :目标、权重和属性 .对决策目标体系的建立、权重的调查和赋值、属性的分析和规范化进行了讨论 ,提出了解决问题的思路和方法 .文中引用了一项工程方案决策实例 ,进一步说明权重 -属性分析方法的应用 .     

道路行车安全性虚拟评价方法研究

针对在道路建成之前很难对设计道路进行有效的安全性评价的问题,在介绍运行车速评价法、速度分布评价法、线形指数评价法和驾驶人工作负荷评价法等国外道路安全评价方法的基础上,提出包括运行车速与设计车速差、相邻路段运行车速差、速度降低因子、横向力系数变化因子以及路段间的加速度值等5个评价因子在内的道路安全评价模型,并确定了相应指标的评价标准.该方法的评价过程包括自行模式和互动模式.自行模式是在驾驶员模糊车速控制模型的基础上预测路段的运行车速,从而进行线形的安全评价;交互模式主要是在虚拟仿真的基础上对道路、隧道、桥梁的交通工程设施、照明等系统进行安全性评价.通过该评价方法可以在道路的设计阶段发现存在的行车安全性问题,通过修改设计或进行安全改善,提高道路的运营安全性.     

“H”桥不平衡电流高频测试法在±660kV换流站中的应用

为保证银川东±660 kV换流站的滤波器和无功补偿装置能安全、可靠、稳定运行,利用高频测量法对换流站的滤波器和无功补偿装置进行“H”桥不平衡电流测试,测试和计算得到的不平衡电流的不平衡度满足相关要求。应用结果表明:高频测试法操作方便、安全,计算简捷,可准确测量“H”桥不平衡电流。     

Estimating separation distance loss probability between aircraft in uncontrolled airspace in simulation

In this article, collision probability between aircraft in uncontrolled airspace is estimated. For that purpose, a large database of aircraft trajectories in the vicinity of Saint-Cyr-l’Ecole airfield (France) is considered and maps of probability collision from simulated aircraft are then estimated. Since the collision between aircraft is a rare event, we applied an importance splitting estimation technique rather than crude Monte Carlo simulations to reduce the variance of the probability estimation. In this study, we demonstrate the high local variability of collision probability in uncontrolled airspace and conclude on the difficulty to set general probability requirements.     

基于熵理论的重大事故复杂链式演化机理及其建模

为完善重大事故演化的本质规律和探究事故后果累积放大原理,从安全物质学的视角提出事故链定义和形成机理,并解析其内涵;通过物质、能量和信息表征事故链演化过程的载体反映;基于物质流、能量流和信息流构建事故链式演化概念模型;基于熵理论和耗散结构理论论述事故阶段演化特性;在此基础上,提炼事故预防与控制策略框架。研究结果丰富了事故链式演化理论,可为事故预防与控制提供更深层次的理论基础。     

系统安全韧性的塑造与评估建模

为完善安全系统学理论体系,立足于理论思辨层面,基于韧性科学和安全系统学,提出安全韧性的定义,并解析其内涵,论述其研究意义。基于此,从3个维度构建系统安全韧性塑造体系的概念模型,并对其进行扼要阐释;深入剖析系统安全韧性塑造体系的作用机理,并构建其作用模型。基于系统安全韧性曲线,构建系统安全韧性评估的数学模型,并进行系统安全韧性曲线的对比分析。研究结果可为安全系统学研究提供新思路和新方法,系统安全韧性是安全系统学和韧性科学交叉领域一个值得关注的重要范式。     

轻度氧化处理纤维素生物降解性的初步研究

以纤维素为原料，通过二氧化氮和过碘酸化学氧化方法，在不同的低取代度条件下，有选择性地在纤维素葡萄糖残基的不同碳原子部位导入特定的取代基（羧基和二醛基），探讨不同的取代基对纤维素生物降解性能的影响．并将处理后所得的纤维素试验，通过土壤埋没，利用土壤中的微生物自然降解，然后测定分子量的变化，定量分析纤维素在不同取代基，不同程度化学处理后，其生物降解性能的变化。实验结果表明：（１）在纤维素葡萄糖残基Ｃ６     

Genetic structure along a gaseous organic pollution gradient: a case study with Poa annua L

The population genetic composition of Poa annua L. was studied by starch electrophoresis along a transect running NE from an organic reagents factory at Shanghai, China. Five enzyme systems were stained. We have reached the following preliminary conclusions: (1). Organic pollution has dramatically changed genotypic frequencies at some loci of Poa annua populations. At polluted sites, significant deviations from Hardy-Weinberg equilibrium were observed on loci Sod-1 and Me due to the excess of heterozygote. Especially in the two nearest sites to pollution source, all the individuals were heterozygous at locus Sod-1. The data suggests that heterozygotes were more tolerant to organic pollution than homozygotes, indicating the fitness superiority of heterozygotes. (2). A tendency towards clinal changes of allele frequencies was found at some polymorphic loci. Frequencies of the common alleles at loci Sod-1, Me and Fe-1 increased as the distance to the pollution source increased. (3). The effective number of alleles per locus, and the observed and expected heterozygosity were much higher in the pollution series than in the clear control site (Botanic Park population), but genetic multiplicity (number of alleles per locus) was lower than for the control. (4). Most genetic variability was found within populations, and only 2.56% were among populations of the polluted series. However, 9.48% of the total genetic variation occurred among populations when including the Botanic Park population. The genetic identity between populations of the pollution series (0.9869-1.0000, mean 0.9941) was higher than those between the pollution series and the Botanic Park population. UPGMA divided the five populations into two groups. One contained the four polluted populations, and the other only contained the Botanic Park population.     

保氮增效剂调节氮肥施用量和利用率的研究 Ⅱ.保氮增效剂在小麦生产中的应用效果

利用田间试验研究了氮肥与保氮增效剂共施的效应函数和保氮增效剂促进小麦省肥增产的比较效果。同的供氮水平,保氮增效剂均能改善小麦植株经济性状,促进籽粒增产,提高氮肥报酬和施肥利润。保氮增效剂用量为氮肥实物量的5%作小麦基肥,旱地增产45～52.5kg/亩,稻田增产54.5～74.5kg/亩,氮肥报酬提高41.4～68.6%。