AgNO<Subscript>3</Subscript> spray tests: advantages,weaknesses, and various applications to quantify chloride ingress into concrete. Part 1: Non-steady-state diffusion tests and exposure to natural conditions

Within the framework of the evaluation and the prediction of chloride-induced corrosion risks, simple and rapid AgNO₃ spray tests can be proposed for various issues. This paper forms the first part of a series. In this first part, the Maultzsch procedure (spraying of 0.1-N AgNO₃ solution + K₂CrO₄) as well as the procedure based on the use of a sole AgNO₃ solution have been investigated on a broad range of concretes. These procedures have also been compared to the Collepardi procedure (spraying of 0.1-N AgNO₃ + fluoresceine). The feasibility of these colorimetric techniques on saturated specimens cast in laboratory, after non-steady-state diffusion tests carried out in various conditions, is discussed. In addition, the results obtained from applying such spray tests in field conditions on cores drilled out from various RC test specimens exposed to a marine environment (tidal zone) and to a road and cold environment (freezing-thawing cycles and spraying of deicing salts) are presented. Colorimetric methods have in particular been applied here to the assessment of the average chloride penetration depth and of its evolution versus time (kinetics). Moreover, the detection threshold of these techniques has been investigated in various environments. The possible sources of discrepancy on the results have been analysed.     

Detrended Fluctuation Analysis of the Human EEG during Listening to Emotional Music

A nonlinear method named detrended fluctuation analysis （DFA） was utilized to investigate the scaling behavior of the human electroencephalogram （EEG） in three emotional music conditions （fear, happiness, sadness） and a rest condition （eyes-closed）. The results showed that the EEG exhibited scaling behavior in two regions with two scaling exponents β1 and β2 which represented the complexity of higher and lower frequency activity besides α band respectively. As the emotional intensity decreased the value of β1 increased and the value of β2 decreased. The change of β1 was weakly correlated with the ＇approach-withdrawal＇ model of emotion and both of fear and sad music made certain differences compared with the eyes-closed rest condition. The study shows that music is a powerful elicitor of emotion and that using nonlinear method can potentially contribute to the investigation of emotion.     

高斯脉冲的超宽带系统抗时间抖动性能分析

由于收发信机之间的不同步、定时追踪及收发间的相对速率等因素所引起的时间抖动在超宽带通信中是不可避免的.详细推导出在单链路及多用户环境中时间抖动对高斯脉冲的跳时脉位调制超宽带系统的性能影响的数学表达式,并作了相应的仿真分析.结果表明,系统的抗时间抖动性能主要取决于单脉冲信号的自相关特性及引入时间抖动的严重程度.     

分子筛吸附器自动再生系统在DCS中实现

介绍了空分装置的分子筛吸附器再生系统的自动控制原理，选用集散控制(DCS)系统实现控制过程，解决了原仪表控制系统的设计、操作和运行上存在问题。新系统更合理、更安全可靠、操作更方便、直观，同时提高了净化工艺的自动化水平。     

500kW以下发电机组常见励磁故障及处理

通过对500kW以下水轮发电机励磁系统使用中常见典型故障结合实际进行深度分析,提出处理方法和整改措施.     

南钢中板厂电气设备可靠性保障方法

本文介绍了南钢中板厂将系统工程最优化技术中的随机服务系统理论和可靠性设计方法引入到电气设备的维护和管理工作中，并结合现场实际情况摸索出一套电气设备可靠性保障方法。     

WSP特殊螺纹接头油井管的研制

介绍了WSP特殊螺纹接头的基本结构和设计思想,运用有限元方法,重点论述了密封设计和连接强度设计的方法和准则,并通过全尺寸试验进行了验证。计算和试验结果表明,该接头具有先进的螺纹形式、合理的扭矩台肩和金属/金属密封结构,有效地克服了API圆螺纹和偏梯形螺纹的不足,螺纹达到了与管体等强度,气密封能力达到了管体的内壁屈服压力。研究结果可以为开发更多适合油气田实际的特殊螺纹接头油井管提供参考。     

合成2,4-二叔丁基苯酚工业试验

以离子交换树脂为催化剂，苯酚和甲基叔丁基醚为原料合成2，4-二叔丁基苯酚(简称2，4酚)，合成产物经过滤再经间歇真空精馏精制提纯，得到高纯度的2，4酚成品。成品精馏后釜中残液在酸性白土催化剂的作用下通过歧化反应生成对叔丁基苯酚，再经精馏提纯得到成品对叔丁基苯酚。通过工艺优化，使2，4酚、对叔丁基苯酚形成联产生产工艺，降低了生产原料消耗和成本。     

VPI粉云母带的选型试验研究

为电机主绝缘VPI工艺选择合适的粉云母带，对几种真空压力浸渍(VPI)用云母带进行了试验研究，分析了选型原则，同时对比了几种粉云母带的性能。将它们应用于模拟线棒中，线棒的试验数据表明：选出的两种云母带的配合可获得优异的性能，达到优等品标准水平。再将少胶云母带应用于电机整机试验，试验结果表明达到了减薄绝缘、降低温升、延缓绝缘老化、提高电机使用寿命的目的。     

单片机自控系统在NS0631型轨道起重机上的应用

单片机自控系统在大型工程机械中得到了越来越广泛的使用，从而使设备的安全性、可靠性大为提高。文章着重分析了NS0631型轨道起重机中自控系统的结构、使用中存在的问题，提出了解决的方法及今后的改进设想。