高强无收缩地聚物的研制与性能研究

当今碱激发工业固废制备的地聚物胶凝材料是最具潜力替代普通硅酸盐水泥的绿色胶凝材料之一。筛选粉煤灰、矿渣和偏高岭土为前驱体,NaOH-水玻璃的混合液体为碱激发剂,高分子吸水性树脂(polymer absorbent resin, SAP)与复合膨胀剂为补偿收缩材料,制备了一种力学性能优异且体积无收缩的地聚物,并通过扫描电子显微镜(Scanning Electron Microscope, SEM)和X-射线衍射(X-Ray Diffraction, XRD)等手段进行微观分析。结果表明,当水固比为0.32、碱含量为12%、水玻璃模数为1.3及复合型膨胀剂掺量为6%时,所制备的地聚物力学性能最好,具备高早期强度的功能;硬化24 h后体积无收缩,膨胀率为0.02%;此时地聚物浆体流动性较大,无泌水现象,结石率高。究其原因在于水化产物中网络状的N-A-S-H凝胶与C-A-S-H凝胶以及少量CaCO₃晶体相互交织,形成致密的结构提高了体系的力学性能,而膨胀剂生成的针棒状AFt和少量Ca(OH)₂晶体补偿收缩的同时,也具有增强功能。本工作可为绿色新型建筑...     

基于ISM和AHP的高原长大隧道施工塌方风险分析

塌方对隧道工程的施工进展极其不利,因此进行塌方事故预防非常重要。对高原长大隧道的施工塌方风险因素进行分析,通过解释结构模型(Interpretive Structure Mode, ISM)判定层次结构模型中同层元素相对重要程度的大小关系;通过层次分析法(Analytic Hierarchy Process, AHP)得出各个影响因素的权重指标,给出影响因素的重要度排序。结果表明：在高原长大隧道施工塌方风险因素中,环境因素重要程度最高,隶属于该指标层的降雨、低温情况对目标层的作用最明显。所建立的层次分析结构模型可以为实际风险分析提供参考。     

基于光纤传感技术的德国铁路数字孪生

德国铁路股份公司（DB）目前正在研究应用光纤传感、数字孪生等技术来提高德国铁路线网的运输能力,并为列车移动闭塞运营及铁路基础设施智能维护提供支持。文章将介绍DBNetz与其合作伙伴联合开展的FOSSIL4.0研究项目,该项目旨在发掘光纤传感（FOS）技术潜在用途和功能,以替代传统无源传感器提供所需数据,为铁路数字孪生打造新的、更精确灵敏的神经系统。     

航空公司监察员胜任力模型实证研究

为研究航空公司监察员胜任岗位的关键能力,通过文献分析、剖析监察员工作流程和职责、访谈等方式获取航空公司监察员胜任力要素。采用探索性因子分析建立航空公司监察员胜任力模型。该模型包括岗位能力、综合知识、应用经验、个性品质4个一级指标,以及事件调查能力、公司规章制度、监察运行程序等22个二级指标。运用结构方程模型（SEM）的理论及方法检验其变量间的关系和模型的有效性。并确定各个指标对模型的影响程度,最后通过灰色关联分析对胜任力模型进行实例评估,结果表明：其构建的胜任力模型评价结果与航空公司监察员的实际工作能力结果相符合,验证了模型的合理性和有效性。     

深圳公交导向发展规划实践

公交导向发展(TOD)是资源节约、环境友好、土地集约型的精明增长方式,是我国大都市发展的战略选择和必由之路。结合深圳市轨道交通二期工程规划的实践,通过对传统轨道交通规划设计体系存在问题的分析,提出了基于公交导向发展的轨道交通规划设计层次体系,并从宏观、中观、微观三个层面探讨了各层次轨道交通规划与各层次城市规划协调配合的目的、内容和方法,为其他城市开展相关规划提供参考。     

电动汽车动力电池采用V2G的有序充放电策略研究

本文针对电动汽车充电站现状问题,介绍了动力V2G有序充放电技术的背景并提出了相应的控制方法。通过建立仿真模型,验证了本文提出的有序充放电控制方法的有效性。研究结果表明,该控制方法可以提高充电站的服务质量和效率,为电动汽车的普及和推广提供有力支持。     

美国波特兰WES通勤铁路对我国市域(郊)铁路发展的启示

波特兰位于美国西部,是俄勒冈州人口最多的城市,有着全美最完善的公共交通设施的美誉。波特兰WES通勤铁路是波特兰大都市区Beaverton和Wilsonville之间既有铁路改建而成,是城市公共交通重要组成部分,于2009年开通运营。通过对波特兰通勤铁路的建设、运营等方面的实地调研成果,并结合国内外其他城市既有经验,根据我国国情,对市域(郊)铁路的规划、建设、运营提出建设性意见,为我国市域(郊)铁路发展提供一定参考。     

Investigation on the formation mechanism of ordered carbide (FeMn)<Subscript>3</Subscript>AlC in the Al added twinning-induced plasticity steels

The spinodal composition zone in Al added Fe-Mn-Al-C twinning-induced plasticity（TWIP） steels can be determined by contents of Al and C and aging temperature together, based on the thermodynamic analysis. Precipitation of ordered（FeMn）₃AlC carbide by the mechanism of spinodal decomposition occurs in the C-rich and Al-rich zone with low aging temperature. Increase of aging temperature shrinks spinodal composition zone to the high Al and C contents. As a result, the precipitation of（FeMn）₃AlC carbide alters from spinodal decomposition to classical nucleation-growth manner gradually. Further calculation indicates that the diffusion of Al can play a key role in determining the growth rate of（FeMn）₃AlC carbide at high aging temperature.     

A hybrid firefly algorithm for optimizing fractional proportional-integral-derivative controller in ship steering

In this paper, a new algorithm which integrates the powerful firefly algorithm(FA) and the ant colony optimization(ACO) has been used in tracking control of ship steering for optimization of fractional-order proportional-integral-derivative(FOPID) controller gains. Particle swarm optimization(PSO) algorithm is also used to optimize FOPID controllers, and their performances are compared. It is found that FA optimized FOPID controller gives better performance than others. Sensitivity analysis has been carried out to see the robustness of optimum FOPID gains obtained at nominal conditions to wide changes in system parameters, and the optimum FOPID gains need not be reset for wide changes in system parameters.     

Human reliability analysis method on armored vehicle system considering error correction

Human reliability analysis(HRA) is an expansion of man-machine engineering. It is also a new multidisciplinary based on behavioral science, cognitive science, information processing, system analysis and probability statistics in order to analyze, predict, reduce and prevent human errors. Firstly, the quantitative analysis model of HRA is proposed based on Markov process theory by using human error probability(HEP) and error correction cycle(ECC) as parameters. And human reliability evaluation criterion is built. Then, the HRA process considering error correction is proposed based on cognitive reliability and error analysis method(CREAM). Finally, according to the characteristics of armored vehicle system, common performance condition(CPC) in CREAM is improved.A reliability impact index is characterized by the overall contexts of tasks. Human reliability evaluation criterion of armored vehicle system is formulated. And the result of HRA is obtained based on the method presented in this paper. In addition, the relative weights are estimated by combining scale of 10/10—18/2 and analytical hierarchy process(AHP), and the triangular fuzzy number considering confidence factor and optimism index is adopted in order to reduce the subjectivity. The analysis results show that the method presented in this paper is reasonable and feasible. Meantime, the method can provide guidance for human reliability analysis of other weapon systems.