燃煤流化床中N2O生成与分解的均相反应机理

介绍由燃料氮生成Ｎ２Ｏ的主要途径是：ＮＣＯ→ＮＯ→Ｎ２Ｏ＋ＣＯ,ＮＨ＋ＮＯ→Ｎ２Ｏ＋Ｈ;分解Ｎ２Ｏ的主要反应是：Ｎ２Ｏ＋Ｈ→Ｎ２十ＯＨ。分析了挥发分中的燃料氮成分、煤种、炉内温度、过量空气系数、分级与单级燃烧方式等因素对Ｎ２Ｏ排放的影响。     

基于改进水平集算法的锅炉承压视觉预警技术

传统锅炉承压预警技术主要依靠人工巡查发现问题,在检测过程中受工作人员自身操作不稳定因素影响,存在故障预警实时性差、盲点多等问题,达不到相应的预警要求.针对此问题,提出基于改进采用水平集算法的锅炉承压预警技术.利用图像处理技术从图像中分割出锅炉承压关键部件,统计关键部件灰度值,并利用灰度值设定特征图像及初始轮廓,设计采用...     

利用印染厂碱减量废水脱除烟气中SO2模拟试验研究

介绍了化纤印染厂坯布前处理工序产生的碱减量废水作为锅炉烟气ＳＯ２的脱硫剂的试验结果,分析了碱减量废水脱硫反应过程及其为碱减量废水综合治理提出了一种新的预处理方法。     

难生物降解的呋吗唑酮模拟废水臭氧氧化的降解机理

采用臭氧氧化法对模拟废水中难生物降解的呋吗唑酮 (FTD)进行降解实验研究 ,藉助UV VIS ,IR ,1 H NMR谱图对反应机理进行了初步探讨 .研究表明 ,pH值显著影响臭氧氧化的反应机理 :酸性条件下 ,臭氧以自身氧化为主 ,可迅速破坏FTD分子的共轭结构 ,但氧化不彻底 ;只有在强碱性条件下且保持臭氧氧化始终以·OH自由基反应为主时 ,方能高效地对FTD分子及中间体进行取代、开环、破坏和氧化 ,生成二氧化碳、水、无机氮及少量残余甲醛、草酸和低级脂肪酸 ,持续反应可完全矿化 .     

大气臭氧损耗中双自由基反应机理的量子化学研究

用量子化学ＲＨＦ理论方法研究了单重态双自由基ＮＨ,ＣＨ２、ＣＣＬ２与大气臭氧Ｏ３的反应机理。在３－２１Ｇ水平上用梯度解析技术优化了上述瓜在的反应物、中间体和产物构型,６－３１Ｇ或６－２１Ｇ计算能量,得到了各构型的有关结构数据。计算表明：上述反应分２步进行,双自由基先与Ｏ３反应生成稳定的中间体,然后在光照条件下中间体分解为ＮＨＯ、Ｈ２Ｃ烽ＣＬ２ＣＯ等稳定分子。从动力学看,２步反应分别为「π４ｓ＋Ｗ２     

突发事件下多种信息交互传播的动力机制与调控策略

针对突发事件下多种信息共存情境中信息交互传播的调控问题,首先界定了该情境中“涌现→传播”过程的组成要素,建立了信息交互关系框架及其系统动力学模型;其次,通过设计和仿真基础情景,将仿真结果与案例进行对比,检验模型的模拟趋势与现实状况的一致性;最后,通过设计和仿真实验情景,考查决策者的关键可控因素对系统演化的影响。研究结果表明:官方渠道所发布信息的可信度、平均个体传播量及群体的立场认知水平,与相信和传播官方渠道信息的人数均正相关,而与相信和传播民间渠道信息的人数均负相关;对各群体数量演化影响的显著性而言,官方渠道信息的平均个体传播量最高,官方渠道信息的可信度次之,群体的立场认知水平较低。     

瓦斯抽采二次膨胀封孔材料膨胀机理及应用研究

为降低瓦斯抽采漏气,开发了1种具备后期膨胀的二次膨胀材料（DE）,以水泥基材料为对比样,利用自制的膨胀力测试装置,以XRD和SEM分别表征其膨胀力及微观结构。研究结果表明:相比水泥基材料,DE材料的膨胀力明显,并表现出显著的时间效应,且DE材料的膨胀力随约束刚度增大而增大;水化1 d时, DE材料较水泥基材料生成更多的钙矾石（AFt）晶体;随着DE材料水化,AFt晶体不断增多,且水化7 d后AFt晶体发生延迟膨胀,这是引起DE材料后期膨胀的主要因素;工程应用表明DE材料可提高瓦斯抽采浓度及纯量,有效改善抽采效果。     

基于大数据的特种设备宏观安全风险预警方法研究

特种设备监管机构在监督检验过程中积累了大量数据资料,为充分挖掘其中的潜在价值,增强监管针对性,提高检验效率,应用并优化关联规则挖掘、社区发现、可视化等数据挖掘技术,构建1种宏观安全风险预警方法。该方法以特种设备安全监督检验大数据为基础,通过挖掘单台设备微观因素间的关联关系,实现整类特种设备宏观安全风险的识别与预警;以2008—2016年全国长管拖车检验数据为例,进行应用实践分析。研究结果表明:该方法可以对区域范围、缺陷类别等多种宏观指标进行预警,指导针对性监管与检验。     

Forward collision warning system impact

Abstract

Objective: The objective of this research is to use historical crash data to evaluate the potential benefits of both high- and low-speed automatic emergency braking (AEB) with forward collision warning (FCW) systems.

Methods: Crash data from the NHTSA’s NASS–General Estimates System (GES) and Fatality Analysis Reporting System (FARS) databases were categorized to classify crashes by the speed environment, as well as to identify cases where FCW systems would be applicable.

Results: Though only about 19% of reported crashes occur in environments with speeds greater than 45?mph, approximately 32% of all serious or fatal crashes occur in environments with speeds greater than 45?mph. The percentage of crashes where FCW systems would be relevant has remained remarkably constant, varying between about 21 and 26% from 2002 to 2015. In 2-vehicle fatal crashes where one rear-ends the other, the fatality rates are actually higher in the struck vehicle (33%) than the striking vehicle (26%). The disparity is even greater when considering size–class differences, such as when a light truck rear-ends a passenger car (15 vs. 42% fatality rates, respectively).

Conclusions: NHTSA and the Insurance Institute for Highway Safety (IIHS) proposed the Automatic Emergency Braking Initiative in 2015, which is intended to make AEB (also called crash-imminent braking) with FCW systems standard on nearly all new cars by September 2022. Twenty automakers representing 99% of the U.S. auto market voluntarily committed to the initiative. Though the commitment to safety is laudable, the AEB component of the agreement only covers low-speed AEB systems, with the test requirements set to 24?mph or optionally as low as 12?mph. The test requirements for the FCW component of the agreement include 2 tests that begin at 45?mph. Only 21% of relevant serious injury or fatal accidents occur in environments at speeds under 24?mph, whereas about 22% of serious or fatal crashes occur in environments with speeds greater than 45?mph. This means that the AEB with FCW systems as agreed upon will cover only 21% of serious or fatal crashes and will not cover 22% of serious or fatal crashes. Because these systems are protective not only for the occupants of the vehicle where they are installed but also other vehicles on the roads, the data indicate that these systems should be a standard feature on all cars for high-speed as well as low-speed environments for the greatest social benefit.