摇摆结构及自复位结构研究综述

城市桥梁是经济和社会发展的重要基础设施,特别是重要桥梁以及由其构成的网络在灾难发生后如何快速恢复,对社会安定和地区发展十分重要。近年来抗震韧性倍受关注,如何考虑结构可恢复性并将韧性纳入桥梁系统抗震性能综合评估和优化,还存在很多问题尚待研究。该文定量分析桥梁震后恢复过程、剩余功能和修复时间与韧性指标间的联系,建立城市桥梁系统性能评估方法。由桥梁不同损伤状态计算不同恢复过程的剩余功能、修复时间、可恢复性和震后经济损失;对震后恢复过程的功能函数模型给出建议,量化不同震后恢复策略的影响;将韧性纳入城市桥梁系统抗震性能框架中,提出城市桥梁系统震后可恢复性评估框架,对风险高低不同采用不同的修复过程;对震后经济损失、可恢复性和震前修/改造成本采用多目标优化算法NSGA-II求解震前提升韧性优化策略,用于抗震加固措施的选取。通过案例给出了方法流程,也为城市桥梁系统地震韧性提升提供了新思路。     

三峡库区滑坡地质力学模型试验技术研究

在三峡库区滑坡地质力学模型试验研究基础上,阐述了滑坡地质力学模型试验的研究现状。指出时间相似比在滑坡模型相似判据研究中须慎重选择;提出以重晶石粉系相似材料能较好模拟软土体滑坡;并介绍了模型相似材料测试中低参数指标测试存在的问题以及模型试验测试技术中的最新进展。     

基于应用服务器的防汛指挥系统框架设计研究

在分析国内防汛指挥系统建设成果的基础上,以淮安防汛指挥系统设计为具体实例,针对地市级防汛指挥决策支持系统的业务逻辑分工和应用特点,提出一个基于应用服务器的地市级防汛指挥系统总体框架。     

土质滑坡分形分析方法的应用

土质滑坡在滑动带形成之前,其矿物颗粒的分布是原生状的,带有很大的随机性。在应力的作用下,矿物颗粒的排列方向不断调整并逐步定向排列,直至滑坡失稳。矿物颗粒的定向排列程度与滑坡的发育过程是相互对应的,它可以用分形来度量。     

基于遗传算法的最大开启电流估计

集成电路设计进入深亚微米阶段后,静态功耗成为低功耗设计中的一个瓶颈．电源门控法可以同时有效地降低动态功耗和静态功耗,是一项具有广阔应用前景的技术．电源门控电路的最大电流是由最大开启电流和最大的正常运行电流决定,它是电路设计的一个十分重要的参数,如何对它进行快速准确的估计已经成为一个新的问题．另外,冒险功耗是电路整体功耗中非常重要的组成部分,该文通过研究发现,在电路开启阶段同样存在冒险,同时消耗了大量的能量．文章考虑了组合电路的冒险现象,提出了一种基于遗传算法的最大开启电流的估计方法,对ISCAS85电路的实验结果表明,电源门控电路的开启最大功耗可能比正常情况下的最大功耗还要大．该文的方法具有较小的复杂性,可以仅用随机模拟的2．77％的时间,获得12．90％的最大开启电流值增量。     

双氧水氧化工艺安全研究策略

国内双氧水绿色氧化工艺蓬勃发展,但工艺本身危险性较高且发生过多起安全事故,严重阻碍了新工艺的开发和推广。为完善工艺安全研究、促进工艺开发,将工艺流程划分为双氧水储存系统、物料进料系统、反应系统、精馏系统等单元,对系统单元涉及的安全问题进行了阐述,总结和探讨了现有研究方法和研究成果。通过对全流程的双氧水氧化工艺中的安全问题和安全研究思路进行梳理分析,为相关工艺开发应用单位建立系统化的安全研究方法和策略、全面提升工艺安全提供建议和参考。     

Making Room for the River

Abstract

Problem, research strategy, and findings: In this study we analyze plan integration for flood resilience in the city of Nijmegen, the site of the largest Room for the River project in The Netherlands. Little is known about the degree to which local and regional plans are coordinated with the national Room for the River program or about the cumulative influence of plans on flood vulnerability. To effectively investigate these issues, we use and build upon the Plan Integration for Resilience Scorecard (PIRS) concept and method, which analyzes the consistency and effects of networks of plans on community vulnerability. We expand the scope to include plans from multiple administrative scales and the focus to include environmental vulnerability. Using a three-phase evaluation process, we demonstrate that Room for the River policies are well integrated in Nijmegen’s network of plans, particularly with respect to flood safety and natural protection. However, we also find that policies at different administrative scales lack consistency in some places, some socially vulnerable neighborhoods receive comparatively little policy attention, and local plans often prioritize development over flood resilience, though higher tier plans sometimes make up for these policy gaps. Flood resilience is still finding its way in the Dutch planning system.

Takeaway for practice: The PIRS offers planning practitioners a method to assess how networks of plans influence community vulnerability and, as demonstrated in this analysis, to determine the degree to which plans at multiple administrative scales target the most physically, socially, and environmentally vulnerable geographic areas. It can be used to support the ambitious goals of a program like Room for the River and align them with local development priorities.     

Quantitative fire risk assessment of cotton storage and a criticality analysis of risk control strategies

Although fires can easily occur during cotton storage, research on cotton storage fire risk assessment is limited. This work focuses on cotton storage fire risk assessment and investigates the criticality of risk control strategies. Bow-tie and Bayesian network models are established to investigate the relationships among accident causes, safety barriers, and possible consequences. The results show that the first safety barrier (detection and extinguishment before fire brigade arrival) is more controllable and more effective than the second safety barrier (fire brigade). Based on the collected probability data, the probability and risk of a common accident are higher than those of a large accident and severe accident when safety barriers succeed; when the first safety barrier fails, the probabilities and risks of large and severe accidents increase by more than 2000 times. The criticality of safety measures is investigated by analysing their structural importance, probability importance, and critical importance. The critical events for fire occurrence are an open flame and sparks during storage, and the critical events for detection and extinguishment before fire brigade arrival are watchkeeper monitoring, regular patrolling, and automatic fire alarm systems. For cotton storage safety, this work and its outcomes are used to support the decision-making of fire risk prevention and control.     

大型流域水电开发公司安全隐患预测研究与实践

国电大渡河流域水电开发有限公司主要负责大渡河流域水电开发及电站运营管理,工作点多、面广、战线长,因此提升安全生产科技化水平至关重要。安全隐患预测研究以历史安全隐患数据为基础,建立安全隐患关键词数据辞典,通过对安全隐患的辨识、分析及应用,选择恰当的空间、时间维度,改进Apriori算法挖掘安全隐患之间的关系,计算隐患之间的因果置信度、支持度和提升度,定量表征不同隐患之间的依存、促进关系,得到新生安全隐患发生的概率。安全隐患预测分析功能已成功上线运行,实现了安全隐患实时预测、分析,有效支持了安全管理决策,为安全生产形势持续稳定提供了坚实保障。     

密闭体系下TATB的热分解动力学与热危害预测

为了解三氨基三硝基苯(TATB)在实际储存、运输过程中的热危险性,利用差示扫描量热仪(DSC)研究TATB在密闭体系下的热行为,并采用模型拟合方法建立TATB的热分解动力学模型。测试结果表明,其分解过程可以用两步平行反应进行描述,动力学模型表示为:第一步F→P1为N级反应,第二步F→P2为自催化反应。基于该模型对自加速分解温度(SADT)进行预测,结果表明,与包装材料相比,装载量对SADT的影响较大;对理想绝热条件下(即Φ=1)的分解过程进行预测,结果表明,起始温度为200℃的绝热诱导期接近450 h,且受热履历影响;对到达指定转化率所需时间(TCL)的预测表明,在100℃的等温环境下,TATB的分解转化率达到0.5%需要4 900 a左右。