基于距离相关系数和支持向量机回归的PM2.5浓度滚动统计预报方案

针对目前空气质量统计预报方法存在的主要缺陷,本文提出了距离相关系数和支持向量机回归相结合的统计预报方案DC-SVR.利用淮安市2013年1—12月PM_(2.5)观测资料和常规气象观测资料,首先在选入预报当日气象要素的基础上,增加选取前期污染物和气象要素作为预报因子,再采用距离相关系数分季节从预报因子中筛选出重要预报因子,最后采用支持向量机回归对PM_(2.5)浓度值进行逐日滚动统计预报.研究发现,淮安地区气温和气压对PM_(2.5)的距离相关性要高于其他气象要素,夏秋季PM_(2.5)与气象要素的距离相关性较春冬季好.基于距离相关系数和支持向量机回归建立DC-SVR模型,PM_(2.5)的试预报值和实测值的全年相关系数高达0.76,平均偏差仅为1.13μg·m~(-3),平均绝对误差为23.47μg·m~(-3).通过与支持向量机回归、人工神经网络的统计预报效果对比,DC-SVR模型有效降低预报因子维数且能自适应选取最佳参数,预报精度显著优于其他3种统计预报方案,可为业务化预报提供参考.     

TiO2/g-C3N4在泡沫陶瓷表面的负载及光催化空气净化性能增强

以市售P25(TiO_2)和g-C_3N_4为原料,以多孔氧化铝泡沫陶瓷为载体,进行了负载型光催化组件的设计与环境应用.运用浸渍提拉-热处理法制备负载P25/g-C_3N_4的泡沫陶瓷组件,对其微结构进行了表征测试,并将其应用于空气中NO的去除.结果表明,P25/g-C_3N_4在氧化铝泡沫陶瓷表面负载牢固,P25/g-C_3N_4禁带结构匹配有利于光生电荷的分离.研究了P25/g-C_3N_4比例对光催化性能的影响,当g-C_3N_4占P25的量为30%时,负载组件的光催化性能最佳,对NO的去除率达到79.6%.在5次循环反应后,负载型光催化剂表现出良好的稳定性.本研究为P25/g-C_3N_4复合光催化剂的空气净化应用提供了思路和技术基础.     

多点激励下圆柱面巨型网格结构地震响应分析

空间相关性对大跨度空间结构的影响不容忽视。本文采用动力时程分析方法对圆柱面巨型网格结构进行了多点激励下的地震响应分析,并与一致激励下的结构地震响应进行对比,探讨了主体结构单独承载和子结构参与协同承载这2种情况下,不同行波激励对结构关键节点和杆件响应的影响及其变化特点;通过比较分析结构在多点激励和一致激励下的响应差异,得出圆柱面巨型网格结构在地震输入时需考虑多点激励的结论,可供该类结构的抗震设计参考。     

基于GIS的土地适宜性评价决策支持系统--以南京市江宁区淳化镇为例

传统的基于GIS建立的土地适宜性评价系统缺乏对空间问题决策的支持能力,而GIS与DSS技术集成建立土地适宜性评价决策系统一方面可以实现对空间数据的管理和分析,另一方面可以利用模型进行辅助决策,有利于解决与空间有关的决策问题。以MapInfo Professional 6.0为基础平台,以Visual 〖XC夏敏字1.TIF,JZ〗6.0为开发工具,建立了一个土地适宜性评价决策支持系统,该系统包括数据库系统、模型库系统、知识库系统以及人机接口4个部分,具有数据输入输出、图属互查、数据空间分析和辅助决策等功能。系统成功应用于南京市江宁区淳化镇农地适宜性评价实践中,应用结果表明系统能为决策者提供多种决策方案,同时又集成了GIS的数据管理和空间分析功能,满足土地适宜性评价的要求,有推广使用的价值。     

基于遗传算法的生命线工程网络抗震优化设计

进行网络抗震可靠性分析的目的,不仅在于定量评价生命线工程网络系统的抗震性能,更重要的是利用这种分析工具指导网络抗震性能的优化设计。以无向边权网络系统为分析对象,分别以管网造价和系统抗震可靠度作为优化目标和约束条件,建立网络系统拓扑优化模型,利用递推分解算法作为网络系统抗震可靠性分析工具,并引入系统单元的灵敏度分析,采用遗传算法求解网络系统的拓扑优化问题,从而发展了一类工程网络抗震优化设计方法。实例分析结果表明,网络系统拓扑结构与系统可靠度之间有显著的正相关关系。     

组织支持感对建筑业农民工不安全行为的影响*

为对建筑业农民工的不安全行为进行科学有效的管理,探讨组织支持感、自我效能感与建筑业农民工不安全行为之间的关系,防止因建筑业农民工不安全行为造成的不安全事件发生,从组织行为学和计划行为学视角出发,以218名一线建筑业农民工为研究对象,通过构建结构方程模型进行实证分析。结果表明:组织支持感的3个维度均可直接对建筑业农民工的不安全行为产生负向显著影响,其中关心利益维度影响最大,工作支持维度次之;建筑业农民工的自我效能感在其组织支持感与不安全行为的负向关系中起到中介作用。     

Precision teaching to improve drivers’ lane maintenance

Introduction: This study investigates the effect of precision teaching signals on lane maintenance. Methods: In experiment 1, the control group drove a simulator with no signals. In experiment 2, drivers were presented with auditory signals depending on their position within or outside the lane. In experiment 3, visual signals were presented in addition to auditory signals to examine the effect of redundancy on drivers’ lane maintenance. Results: Results showed an improvement in lane maintenance in experiment 2. Cross-experiment analysis indicated this effect not to be the result of learning. Data from experiment 3 also showed that presenting redundant signals did not further reduce lane variability or help drivers maintain a more central position within the lane. Conclusions: Taken together, data suggest precision teaching be effective as an educational tool to improve lane maintenance. Practical Applications: Our study shows the potential for precision teaching to serve as a valuable tool in driver training.     

A scoping review of post-disaster social support investigations conducted after disasters that struck the Australia and Oceania continent

This scoping review provides a summary of research findings on social support dynamics in the wake of disasters that occurred on the continent of Australia and Oceania between 1983 and 2013. Forty-one studies, quantitative and qualitative, were summarised, investigating different facets of post-disaster supportive interactions. All inquiries assessed disasters resulting from natural hazards, with the majority of them conducted following events in Australia and New Zealand. The review revealed similar patterns of post-disaster social support dynamics that routinely unfold after disastrous incidents all over the world. Consistent with the disaster mental health literature, the documentation of social support mobilisation and social support deterioration processes was common. Salutary direct effects of supportive behaviours on post-disaster psychological distress were also highly evident. Most studies, however, posed research questions or hypotheses that lacked empirical or theoretical grounding. In conclusion, the review offers several recommendations on how to advance research on post-disaster social support.     

TUGAI: An Integrated Simulation Tool for Ecological Assessment of Alternative Water Management Strategies in a Degraded River Delta

The development of ecologically sound water allocation strategies that account for the needs of riverine ecosystems is a pressing issue, especially in semiarid river basins. In the Aral Sea Basin, a search for strategies to mitigate ecological and socioeconomic deterioration has been in process since the early 1990s. The Geographic Information System–based simulation tool TUGAI has been developed to support the policy determination process by providing a simple, problem-oriented method to assess ecological effects of alternative water management strategies for the Amudarya River. It combines a multiobjective water allocation model with simple, spatially explicit statistical and rule-based models of landscape dynamics. Changes in environmental conditions are evaluated by a fuzzy habitat suitability index for Populus euphratica, which is the dominant species of the characteristic riverine Tugai forests. Water management scenarios can be developed by altering spatiotemporal water distribution in the delta area or the amount of water inflow into the delta. Outcomes of scenario analysis are qualitative comparisons of the ecological effects of different options for a time period of up to 28 years. The given approach utilizes different types of knowledge, from quantitative hydrological data to qualitative local expert knowledge. The main purpose of the tool is to integrate the knowledge in a comprehensive way to make it available for discussions on alternative policies in moderated workshops with stakeholders. In this article, the modules of the tool, their integration, and three hypothetical scenarios are presented. Based on the experience gained when developing the TUGAI tool, we propose that the general framework can be transferred to other areas where tradeoffs in water allocation between the environment and other water users are of major concern. The potential for a simulation tool to structure and inform a complex resource management situation by involving local experts and stakeholders in the development of possible future scenarios will become increasingly valuable for transparent and participatory resource management.     

楚雄德胜钢铁公司烧结机尾除尘改造实践

介绍楚雄德胜钢铁公司19·6m2烧结机尾除尘系统改造工程中使用三电极电除尘器的工艺及有关设计技术问题,并根据使用效果进行分析总结。结果表明,在设计参数选择恰当的情况下,三电极电除尘器对烧结烟气有较好的除尘效果,这些经验和操作中存在的问题供烧结机尾除尘工程设计参考。