A case study on period vehicle routing in a refuse collection system

Period vehicle routing, a multi-period extension of the capacitated vehicle routing problem, is the problem of determining a service combination of each customer as well as the vehicle routes in each period of the planning horizon while satisfying the restrictions on the vehicle capacity and the travel distance (time). The problem can typically be found in refuse collection systems in which end-of-life products or wastes are collected and moved to the facilities where further treatment is taken care of. In this study, we report a case study on the problem for the objective of minimising the fleet size, i.e. the maximum number of vehicles simultaneously required over the planning horizon. To solve the problem, we adopt the two-stage heuristic in which an initial solution is obtained by assigning a service combination to each collection point, and then it is improved by changing the service combination assigned to each collection point. Computational experiment was done on the case data and significant improvement over the conventional method is reported.     

When do you procrastinate? Sleep quality and social sleep lag jointly predict self‐regulatory failure at work

This study investigates antecedents of procrastination, the tendency to delay the initiation or completion of work activities. We examine this phenomenon from a self‐regulation perspective and argue that depleted self‐regulatory resources are an important pathway to explain why and when employees procrastinate. The restoration of self‐regulatory resources during episodes of non‐work is a prerequisite for the ability to initiate action at work. As sleep offers the opportunity to replenish self‐regulatory resources, employees should procrastinate more after nights with low‐quality sleep and shorter sleep duration. We further propose that people's social sleep lag amplifies this relationship. Social sleep lag arises if individuals' preference for sleep and wake times, known as their chronotype, is misaligned with their work schedule. Over five consecutive workdays, 154 participants completed a diary study comprising online questionnaires. Multilevel analyses showed that employees procrastinated less on days when they had slept better. The more employees suffered from social sleep lag, the more they procrastinated when sleep quality was low. Day‐specific sleep duration, by contrast, was not related to procrastination. We discuss the role of sleep for procrastination in the short run and relate our findings to research highlighting the role of sleep for well‐being in the long run. Copyright © 2016 John Wiley & Sons, Ltd.     

PAC-SBR与SBR处理垃圾渗滤液对比研究

利用PAC-SBR与SBR对垃圾渗滤液进行了对比试验研究,从处理效果、微生物性状以及生化反应表征特性进行了研究,结果表明,同条件SBR法相比,PAC-SBR法可以取得更高的有机物去除、脱氮和脱色效果。COD、色度和NH3去除率分别可达到81.6%、48.6%和90%以上。     

上向流曝气生物滤池处理煤矿矿区生活污水技术研究

概述了我国煤矿矿区生活污水特点、处理技术发展及上向流曝气生物滤池技术特点,对生物滤池处理矿区生活污水进行试验研究,为工程设计提供合适的技术参数,同时进行了工业性试验研究。结果表明,混凝沉淀后进行生物滤池处理矿区生活污水技术可行,投资省,运行费用低,出水达到生活杂用水标准,可实现矿区生活污水资源化利用。     

上海市污泥集装化运输可行性研究

随着上海市生活垃圾集装化运输系统的逐步完善和发展,上海市污泥的集装化运输逐渐被提上日程。本文通过对上海市中心城区的10座城市污水处理厂的污泥产量、污泥含水率、污泥运输道路和装卸环境等进行系统调研,综合分析和研究了上海市各污水处理厂污泥集装化运输的可行性,并进一步研究了污泥性质对集装化运输的影响。结果表明,上海市中心城区仅白龙港污水处理厂含水率约为60%的深度脱水污泥符合污泥集装化运输的要求;深度脱水污泥性质较为稳定,对各种钢材料的腐蚀性为0.00016~0.00125 mm/a,对集装化运输影响较小,但污泥释放的氨气浓度高达173.66 mg/m3,影响集装化运输,需采取水雾喷洒等措施进行控制。     

中国资源型城市循环经济发展水平的聚类实证研究

由于粗放型的发展模式受到严格限制,资源型城市的发展普遍面临严峻困境,发展循环经济,是资源型城市实现可持续发展的必然途径.对资源型城市循环经济发展水平进行计量实证研究,找出其发展共性和差异具有很强的现实意义和理论价值.通过构建资源型城市循环经济发展评价指标体系,收集涵盖全国34个典型资源型城市、17个资源枯竭城市的39个地级资源型城市和参照城市北京的22个原始指标数据,用功能互补的因子分析和聚类分析进行实证研究:首先用因子分析法对原始数据进行分析,用得到的8个因子代替原来的22个指标,进一步进行K-means聚类分析,对资源型城市的循环经济发展水平做了较为完整的评价,结果显示:资源型城市循环经济发展整体水平不高,循环经济发展理念有待深入,东营、克拉玛依等城市经济发展状况很好,为循环经济发展提供了良好的经济基础,晋城在循环经济的某些领域取得了较好的效果,白山的循环经济发展水平相对最低.     

甲苯废气的生物净化性能与动力学模拟研究

该研究以轻质陶块为填料,探讨了生物膜填料塔净化处理高气体流量负荷下低浓度甲苯废气的生物降解性能。实验结果表明：生物膜填料塔对甲苯具有较强的降解能力,净化效率维持在40．6％～61．9％;随着气体流量负荷和入口气体甲苯浓度负荷的增加,甲苯的净化效率也随之下降。结合实验数据对“吸附-生物膜”理论的动力学模式进行模拟研究,对比验证结果表明动力学模拟计算值和实验值之间均有很好的拟合性,从而验证了该模型的正确性．     

红外测温法测定硫化矿石堆自热温度的影响因素研究

硫化矿自燃是一个以氧化放热为主、自发产生热量及热量积蓄引起硫化矿堆升温的非常复杂的物理化学过程.因此,研究硫化矿自热过程是研究硫化矿自燃早期预测预报方法的前提.文章以红外非接触方式,利用RaytekminiTemp红外测温仪和CENTER可记录温度计测定硫化矿石堆氧化自热温度,重点分析了测定过程中的实际温度时影响精度的有关因素,主要有矿样种类、矿样温度、矿样块度、检测距离、环境温度、光束与矿样的夹角.通过实验室研究,为研制出专门用于舍硫矿自燃预测预报的装置提供理论依据,从而达到预测预报硫化矿自燃的目的.     

文山县饮用水水源铁锰超标调查研究、处理方法及建议

结合文山县当前饮用水源中铁锰超标的实际情况，分析了周边环境对文山县饮用水水源地的影响，阐述了饮用水中铁、锰超标对人体健康的危害，提出了解决饮用水中铁锰超标问题的必要性和可行方法，并提出相关的对策和建议。     

Simultaneous size characterization and mass quantification of the in vivo core-biocorona structure and dissolved species of silver nanoparticles

Size characterization of silver nanoparticles with biomolecule corona(AgNP@BCs) and mass quantification of various silver species in organisms are essential for understanding the in vivo transformation of Ag NPs. Herein, we report a versatile method that allows simultaneous determination of the size of AgNP@BCs and mass concentration of various silver species in rat liver. Both particulate and ionic silver were extracted in their original forms from the organs by alkaline digestion, and analyzed by size exclusion chromatography combined with inductively coupled plasma mass spectrometry(SEC-ICP-MS). While the silver mass concentrations were quantified by ICP-MS with a detection limit of 0.1 μg/g, the effective diameter of AgNP@BCs was determined based on the retention time in SEC separation with size discrimination of 0.6-3.3 nm. More importantly, we found that the BC thickness of AgNP@BCs is core size independent, and a linear correlation was found between the effective diameter and core diameter of AgNP@BCs in extracted tissues, which was used to calibrate the core diameter with standard deviations in the range of 0.2-1.1 nm. The utility of this strategy was demonstrated through application to rat livers in vivo. Our method is powerful for investigating the transformation mechanism of Ag NPs in vivo.