Influence of visual clutter on the effect of navigated safety inspection: a case study on elevator installation

Introduction. Navigated safety inspection based on task-specific checklists can increase the hazard detection rate, theoretically with interference from scene complexity. Visual clutter, a proxy of scene complexity, can theoretically impair visual search performance, but its impact on the effect of safety inspection performance remains to be explored for the optimization of navigated inspection. This research aims to explore whether the relationship between working memory and hazard detection rate is moderated by visual clutter. Methods. Based on a perceptive model of hazard detection, we: (a) developed a mathematical influence model for construction hazard detection; (b) designed an experiment to observe the performance of hazard detection rate with adjusted working memory under different levels of visual clutter, while using an eye-tracking device to observe participants’ visual search processes; (c) utilized logistic regression to analyze the developed model under various visual clutter. Conclusion. The effect of a strengthened working memory on the detection rate through increased search efficiency is more apparent in high visual clutter. This study confirms the role of visual clutter in construction-navigated inspections, thus serving as a foundation for the optimization of inspection planning.     

Effects of aircraft noise and speech on prose memory: What role for working memory capacity?

Previous research indicates that aircraft noise and meaningful background speech are particularly detrimental to school adolescents' ability to remember what they read, but until now the effects from aircraft noise and speech have never been compared directly in an experiment. Furthermore, individual differences in susceptibility to these effects are not well understood. The present investigation addressed these two issues. Adolescents attending upper secondary school were recruited as participants and the data collection was made in their ordinary classrooms. The results from two experiments revealed that speech is more detrimental to prose memory than is aircraft noise, and individual differences in working memory capacity contributes more to individual differences in susceptibility to the effects of aircraft noise on prose memory than to the effects of speech. Some applied implications of those findings to noise abatement interventions are suggested.     

高温碟型双金属片动作响应特性技术研究

高温碟形双金属片是火警温度继电器的核心元件，结构复杂，为了研究其受热动作响应特性，采用有限元分析方法，通过Solidworks结合ANSYS对双金属片进行热-结构耦合场分析，获得了碟形双金属片的受热动作响应特性，并且通过不断改变高温碟形双金属片的外形结构进行求解分析，根据分析结果总结高温碟形双金属片的结构与其受热动作响应特性之间的关系，为高温碟形双金属片的结构参数设计和数据调节提供理论依据。     

高速列车纵向对称面气动噪声计算及外形优化

将大涡模拟法与Lighthill-Curle声学比拟理论相结合,计算了高速列车纵向对称面的气动噪声,探明了纵向对称面气动噪声的频谱特性及其变化规律,得出了车辆连接处的优化外形。结果表明,低频时,气动噪声幅值较大,随着频率升高,幅值下降。当列车运行速度一定时,距离气动噪声源越远,声压的衰减幅度越少。随着列车运行速度增加,距离气动噪声源越远,声压的增幅越小。脉动压力是气动噪声的源,在车辆连接处采用平滑的Nurbs曲线过渡,以减少列车运行过程中产生的脉动压力,能有效降低气动噪声。     

Metal composition of layered double hydroxides (LDHs) regulating ClO4- adsorption to calcined LDHs via the memory effect and hydrogen bonding

A series of calcined carbonate layered double hydroxides （CLDHs） with various metal compositions and different M^2＋/M^3＋ ratios were prepared as adsorbents for perchlorate. Adsorption isotherms fit Langmuir model well, and the adsorption amount followed the order of MgA1-CLDHs 1〉 MgFeCLDHs 〉〉 ZnA1-CLDHs. The isotherms of MgA1-CLDHs and MgFe-CLDHs displayed a two-step shape at low and high concentration ranges and increased with an increase in the M^2＋/M^3＋ ratio from 2 to 4. The two-step isotherm was not observed for ZnA1-CLDHs, and the adsorption was minimally affected by the M^2＋/M^3＋ ratio. The LDHs, CLDHs and the reconstructed samples were characterized by X-ray diffraction, SEM, FT-IR and Raman spectra to delineate the analysis of perchlorate adsorption mechanisms. The perchlorate adsorption of MgA1-CLDHs and MgFe-CLDHs was dominated by the structural memory effect and the hydrogen bonds between the free hydroxyl groups on the reconstructed-LDHs and the oxygen atoms of the perchlorates. For ZnAI-CLDHs, the perchlorate adsorption was controlled by the structural memory effect only, as the hydroxyl groups on the hydroxide layers preferred to form strong hydrogen bonds with carbonate over perchlorate, which locked the intercalated perchlorate into a more confined nano-interlayer. Several distinct binding mechanisms of perchlorate by CLDHs with unique M^2＋ ions were proposed.     

泥石流堆积模式的试验研究

泥石流的堆积形态和范围是泥石流危险区划分的重要参数，它们不仅与泥石流体浓度（Ｇｖｔ）、下游流路坡度（Ｑｕ）有关，还与流通过 坡度（Ｑｃ和冲出量有关。本文通过小型水槽试验，求得了泥石流堆积范围与形态比的堆积模式，并根据野外测量的堆积形态进行了泥石流体浓度的计算和验证，该模式可为泥石流防治工程的设计提供有科学依据的参数。     

斜拉索风雨激振的形状记忆合金半主动控制数值模拟分析

斜拉索风雨激振的控制是斜拉桥工程的关键技术难题之一。本文利用轴向设置的形状记忆合金(ShapeMemory Alloy,SMA)作动器,对斜拉索的风雨激振进行了半主动控制数值模拟分析,控制规则采用KOBORI开关控制。数值分析结果表明,SMA半主动控制可有效的控制拉索的风雨激振;SMA的设置长度及初始的应变大小对控制效果有较大的影响,SMA长度越长,初始应变越大,其控制效果越佳。对由SMA控制引起的拉索张力变化做了分析,其张力的变化很小,在可接受的范围内。研究表明,SMA作动器在参数非理想时控制效果可能有所降低,但控制的稳定性良好。     

应用形状记忆合金-橡胶复合支座的结构隔震

对橡胶支座存在的问题进行了分析，介绍了SMA-橡胶复合支座的基本构造和工作原理，建立了设置不同支座的单自由度结构的运动方程。应用大型有限元软件ANSYS对分别设置固定支座、普通叠层橡胶支座和形状记忆合金（SMA）-橡胶复合支座这3种不同支承条件的结构进行了，单向地震作用下的隔震仿真模拟，及节点位移和加速度的时程分析。分析表明，SMA-橡胶复合支座和普通叠层橡胶支座都能有效地减小结构的位移和加速度反应，而SMA-橡胶复合支座比普通叠层橡胶支座能更有效地减小结构的绝对位移反应，防止因隔震层位移过大而导致支座失稳。     

大批波纹拱壳屋顶倒塌的事故分析及其安全改进措施

波纹拱壳屋顶是一种新型的大跨轻钢结构。由于其造价低、施工期短 ,在国内已得到大规模的应用。1996年起 ,我国有几十个大跨波纹拱壳屋顶由于大风或大雪而相继发生坍塌事故 ,这类伤亡事故引起了业界的高度重视。笔者从波纹拱壳屋顶的设计理论、成型工艺、施工工艺、材质等几个方面探讨了波纹拱壳屋顶发生坍塌的原因 ,分析了影响波纹拱壳屋顶安全性能的几个主要因素 ,还提出了防止该结构倒塌的安全改进措施     

白腐真菌培养条件对其分泌木质素降解酶的影响

应用摇瓶试验研究了不同白腐真菌培养条件对其产酶的影响.通过控制不同转速、投加载体等方式考察了白腐真菌的产酶情况.结果表明,在悬浮培养方式下,转速为160r/min时获得的锰过氧化物酶最高(481.6U/L),其酶活是静置、120r/min条件下培养的65倍和43倍;投加载体后,载体固定化培养获得的木质素过氧化物酶酶活是悬浮培养的71倍,载体投加量对其产酶影响很大,只有当载体处于非浸没状态时才有利于酶活产生,否则酶活极低.因此,选择载体固定化—非浸没—振荡培养方式培养白腐真菌可获得更高的产酶量和酶活.