Seismic vulnerability assessment of water supply network in Tianjin,China

The water supply network （WSN） system is a critical element of civil infrastructure systems. Its complexity of operation and high number of components mean that all parts of the system cannot be simply assessed. Earthquakes are the most serious natural hazard to a WSN, and seismic risk assessment is essential to identify its vulnerability to different stages of damage and ensure the system safety. In this paper, using a WSN located in the airport area of Tianjin in northern China as a case study, a quantitative vulnerability assessment method was used to assess the damage that the water supply pipelines would suffer in an earthquake, and the finite element software ABAQUS and fuzzy mathematic theory were adopted to construct the assessment method. ABAQUS was applied to simulate the seismic damage to pipe segments and components of the WSN. Membership functions based on fuzzy theory were established to calculate the membership of the components in the system. However, to consider the vulnerability of the whole system, fuzzy cluster analysis was used to distinguish the importance of pipe segments and components. Finally, the vulnerability was quantified by these functions. The proposed methodology aims to assess the performance of WSNs based on pipe vulnerabilities that are simulated and calculated by the model and the mathematical method based on data of damage. In this study, a whole seismic vulnerability assessment method for a WSN was built, and these analyses are expected to provide necessary information for a mitigation plan in an earthquake disaster.     

Analyzing motorists’ responses to temporary signage in highway work zones

For decades, the importance of highway work zone safety has increased considerably with the continual increase in the number of highway work zones present on highways for repairs and expansion. Rural work zones on two-lane highways are particularly hazardous and cause a significant safety concern due to the disruption of regular traffic flow. In this study, researchers determined motorists’ responses to warning signs in rural, two-lane highway work zones. The researchers divided vehicles into three classes (passenger car, truck, and semitrailer) and compared the mean change in speed of these classes based on three different sign setups: portable changeable message sign (PCMS) OFF, PCMS ON with the message of Slow Down, Drive Safely, and a temporary traffic sign (W20-1, “Road Work Ahead”). Field experiments were conducted on two two-lane work zones with flagger control. Statistical analyses were performed to determine whether there was a significant interaction between motorists’ responses and the sign setups. Data analysis results show that a visible PCMS, either turned on or off, was most effective in reducing truck speeds in rural, two-lane work zones. The temporary traffic sign (W20-1) was more effective in reducing the vehicle speeds of passenger car and semitrailer. Results of this research project will help traffic engineers to better design the two-lane work zone setup and take necessary safety countermeasures to prevent vehicle crashes.     

基于可公度方法的陕西及邻近地区重大自然灾害发生趋势探讨

针对重大自然灾害预测预报的世界难题,在可公度方法的基础上,提出时间对称性观点;进而对陕西及可能影响到陕西的部分全国重大自然灾害进行了趋势研究。研究认为,2010年、2012年、2013年及2019年,陕西及邻近地区有发生重大灾害的可能性。并认为,适应全球变化首先要适应频繁的自然灾害。     

钢桁架-钢筋混凝土管柱结构风致响应试验研究

大跨长悬挑钢-混凝土高柔结构的动力性状决定了其风振系数不能采用我国规范中的方法来计算。制作气弹性模型进行了动力性状、脉动风作用下位移响应、加速度响应、扭转响应、气动力稳定性等问题的相关试验,计算得到了风振系数,分析了风速、风向角、风机、周围建筑物等因素对风振系数的影响,给出了风振系数的建议值。将试验结果与其他方法计算的结果进行了对比分析,结果表明,试验结果偏大,符合风洞试验原理。研究结果为工程设计提供了基础资料,可供同类工程参考。     

气体放电非平衡等离子体化学脱硫脱硝理论基础研究

研究了烟气电离放电脱硫脱硝的非平衡等离子体化学反应过程,采用介质阻挡强电离放电方法产生高电子浓度(＞10     

醛类化合物分子结构与对鼠急性毒性关系

通过检索美国国立职业与卫生研究所化学物质毒性效应登录 ( RTECS) 1998年版光盘系统 ,搜集了 88种醛类化合物对大鼠急性毒性口服 LD₅₀ 数据 ,并利用遗传神经网络建立了醛类化合物分子结构与对大鼠急性毒性关系的 BP神经网络模式 ,模式的交互检验相关系数达 0.83～ 0.87,具有较强的预报能力 .遗传神经网络是由遗传算法和神经网络耦合而成 ,文章详细讨论了遗传神经网络的构造以及利用遗传神经网络建立 QSAR模型的方法 .     

废轮胎的热解及其产物分析

研究了废轮胎热解产生的三相 (气、液、固 )产率与裂解温度的关系 ,气相组成与温度的关系 ,以及氢氧化钠作为催化剂加入热解体系对三相产率和气体组成的影响 .实验表明 ,轮胎橡胶的热稳定性分为 :～ 200℃,200℃～300℃及300℃以上3个区域 .在200℃以上时 ,随着温度升高 ,固体产率减少 ,气体产率增加 ,液体产物的产率在 500℃左右出现一个峰值 .加入 4%NaOH作催化剂以后 ,在相同的温度下固态碳黑和液态油的产率均有所提高 ,而相应混合气的产率降低 .实验确定了所用混合胶粉主要为合成橡胶 .不同温度下热解所产生的液体产物的红外谱图及裂解色谱图表明 ,300℃时主要是助剂分解,400℃左右主要是聚异戊二烯(天然胶)开始裂解,600℃以上残留物开始裂解.     

高浓度硝酸盐氮HACH测定方法中试剂国产化的探讨

通过试验对高浓度硝酸盐氮 HACH测定方法中各试剂的国产化进行探讨 ,认为用 1 0∶ 1硫酸溶液与 0 .0 4 g变色酸替代原进口试剂较合理 ,并有较好精密度与回收率。     

台风暴雨

台风是经常侵袭我国的一种强烈天气系统。时常在我国造成严重的灾害。本文主要讨论与台风有关的暴雨特征。出没于中国大陆及沿海的台风暴雨主要有三种类型：１）台风之气旋性环流内的暴雨；２）台风外缘与西风带或辐热带系统等相互作用的暴雨；３）台风临近前的前置暴雨及其消散时的滞后暴雨。其中，第一种是最普遍常见的；而后两种亦常造成严重的危害，不可忽视。登陆我国的台风，由于其自身及外围环流系统和下垫面环境条件的不同，     

快速测定地面水中阴离子表面活性剂

通过比对实验来探讨用孔雀绿试剂法测定地面水中阴离子表面活性剂的可行性。实验结果证明,该方法精密度与准确性均达到现行监测规范要求,与国标亚甲基蓝分光光度法相比具有操作简单,不用萃取剂,分析时间短的优点,可适用于地面水的监测。