气象条件对2013—2015年冬季关中地区空气质量的影响

大气污染是由过度的人为源排放和不利于大气污染扩散的气象条件共同作用的结果,通过探讨天气形势及气象要素与细颗粒物（PM_2.5）的关系,分析气象条件对空气质量的影响,从而为关中地区的环境治理提供有利的参考依据。本文利用NCEP-FNL再分析资料、环境监测资料及有关的降水数据,对2013?—?2015年冬季关中地区空气质量的演变趋势及其与气象条件的关系进行了研究。结果表明：2013?—?2015年冬季关中地区平均PM_2.5浓度分别为159.5 μg???m_?3,74.2 μg???m_?3,101.8 μg???m_?3,呈现出先明显下降然后又回升的趋势。对2013?—?2015年冬季关中地区天气形势的分类分析表明：这三年关中冬季的有利天气形势呈先上升后下降的趋势,能基本解释同期关中地区PM_2.5的演变趋势。有利天气形势不但会使当天的PM_2.5降低,还会使第二天的PM_2.5维持在较低的水平。因此,有利天气形势天数的增加会使冬季的整体PM_2.5 浓度下降;反之,有利天气形势的减少或不利天气形势的持续则会使PM_2.5浓度飙升到很高的水平。此外,风速与每天的PM_2.5浓度呈显著的负相关,可以解释同一天气形势下日平均PM_2.5浓度的变化。降水对污染物有明显的湿清除作用,但降水并不是造成2014年关中地区PM_2.5浓度偏低的主要原因。     

南京青奥会期间不同天气条件下大气气溶胶中水溶性离子的分布特征

为研究青奥会期间不同天气条件下水溶性离子粒径分布特征,使用β射线测尘仪、安德森9级采样器和IC型离子色谱分析仪对南京2014-08-06~2014-09-04的PM_(2.5)、水溶性离子进行观测分析.将观测期间划分为晴天、雨天和阴天这3种天气类型.PM_(2.5)在不同天气条件下的平均浓度为晴天阴天雨天.PM_(1.1)、PM_(1.1~2.1)和PM_(2.1~10)中水溶性离子的浓度均是晴天阴天雨天,且降雨过程对细粒子的去除作用更为明显.Ca~(2+)和Mg~(2+)谱分布类似,呈双峰分布,降雨对SO_4~(2-)和NH_4~+在0.65~1.1μm清除作用较强.不同天气条件下NO_3~-/SO_4~(2-)比值均小于1,雨天和阴天时的NO-3/SO_4~(2-)值高于晴天.3种天气条件下SOR和NOR的值均大于0.1,SO_2和NO_2发生不同程度的二次转化,大气中存在更多的二次颗粒物.     

Extension of TACOM to the complexity of tasks designed for abnormal situations in nuclear power plants

TACOM (TAsk COMplexity) is a measure for evaluating the complexity of tasks prescribed for emergency situations in nuclear power plants. Five sub-measures constituting TACOM represent five different aspects of the task complexity exhibited in operating procedures for emergency situations. The practicality of TACOM has been verified through a series of empirical studies. However, tasks designed for abnormal situations that can significantly affect the safety of nuclear power plants, also need a proper measure for evaluating their complexity. TACOM provides a process, a systematic cognitive task analysis method and a set of guidelines to support its application. Therefore, although the characteristics of abnormal task situations are not the same as those of emergency situations, TACOM seems to be reasonably applied to abnormal situations or at least to offer meaningful insights for developing a measure for evaluating the complexity of tasks in abnormal situations. Thus this study examined the applicability of TACOM to abnormal situations through case studies. Particular attention was paid to the sufficiency and appropriateness of the three methodological tools, which are the process, the cognitive task analysis method and the set of guidelines. Collective consideration of the case studies and the characteristics of tasks prescribed for abnormal situations led us to draw the conclusion that TACOM could be reliably used for abnormal situations as well. This paper reports the process of how to apply TACOM to the tasks of abnormal situations and discusses some lessons learned through this application.     

Assessing effects of aerobic and anaerobic conditions on phosphorus sorption and retention capacity of water treatment residuals

Water treatment residuals (WTRs) are the by-products of drinking water clarification processes, whereby chemical flocculants such as alum or ferric chloride are added to raw water to remove suspended clay particles, organic matter and other materials and impurities. Previous studies have identified a strong phosphorus (P) fixing capacity of WTRs which has led to experimentation with their use as P-sorbing materials for controlling P discharges from agricultural and forestry land. However, the P-fixing capacity of WTRs and its capacity to retain sorbed P under anaerobic conditions have yet to be fully demonstrated, which is an issue that must be addressed for WTR field applications. This study therefore examined the capacity of WTRs to retain sorbed P and sorb further additional P from aqueous solution under both aerobic and anaerobic conditions. An innovative, low cost apparatus was constructed and successfully used to rapidly establish anoxic conditions in anaerobic treatments. The results showed that even in treatments with initial solution P concentrations set at 100 mg l(-1), soluble reactive P concentrations rapidly fell to negligible levels (due to sorption by WTRs), while total P (i.e. dissolved + particulate and colloidal P) was less than 3 mg l(-1). This equated to an added P retention rate of >98% regardless of anaerobic or aerobic status, indicating that WTRs are able to sorb and retain P in both aerobic and anaerobic conditions.     

地铁运营工况点型探测器探测性能试验研究

为了解地铁运营期点型探测器受活塞风的影响及其适应性和设置方式,采用碎纸、棉绳和聚氨酯塑料试验火,在地铁站台进行初期火灾探测实体试验。对2种类型点型探测器在模拟运营工况与夜间停运工况的适应性进行对比分析,同时,针对设置镂空格栅吊顶地铁车站,研究点型探测器在吊顶上下不同安装位置时的响应性能。试验结果表明:列车运行产生的活塞风扰乱烟气的上升和扩散运动,对阴燃火源烟气影响显著,有烟明火烟气能较快地通过格栅空隙到达中板;在地铁运营工况条件,烟温复合探测器响应性能表现不理想,不同空间安装的点型感烟探测器报警时间与报警数量均较停运工况发生变化。设置镂空格栅吊顶车站站台层公共区运营期使用点型感烟探测器进行保护时,应当贴中板和贴格栅吊顶双层安装。     

泸州市环保产业调查与分析

环保产业作为环境与经济协调发展的关键,是推进生态文明建设的关键举措。通过泸州市2008年环保及相关产业调查,对相关企业规模、结构、从业人员等相关数据进行分析,阐述了环保产业在泸州市经济发展中的作用和存在的问题。并针对泸州市社会经济发展现状,提出了政府调控、统筹规划、加大投入、全力扶持等大力发展泸州市环保产业的建议。     

微量钒的分光光度测定方法研究进展

综述分光光度法测定试样中微量钒,并对各种方法的测量条件、特点以及应用范围作了较为详尽的论述和介绍。     

Evaluating post-Katrina recovery in Mississippi using repeat photography

Hurricane Katrina of August 2005 had extensive consequences for the state of Mississippi in the United States. Widespread infrastructure and property damage, massive social dislocation, and ecological loss remain among the many challenges faced by communities as they work towards 'normalcy'. This study employs repeat photography to understand differential recovery from Hurricane Katrina in Mississippi. Revealing change with conventional landscape photography, a process known as repeat photography, is common in the natural sciences. Simply stated, repeat photography is the practice of re-photographing the same scene as it appears in an earlier photograph. Photographs were taken at 131 sites every six months over a three-year period. Each photograph was assigned a recovery score and a spatially interpolated recovery surface was generated for each time period. The mapped and graphed results show disparities in the progression of recovery: some communities quickly entered the rebuilding process whereas others have lagged far behind.     

新化县水车镇泥石流灾害研究

以湖南省新化县水车镇泥石流为研究案例,根据初勘、详勘资料,分析了该泥石流的形成条件,定量计算了相应的运动参数,预测了它的发展趋势,最后指出,生物工程〔植树造林〕防治措施在花岗岩残坡积层泥石流场地的适宜性尚有待商榷。     

Monitoring and estimating the flow conditions and fish presence probability under various flow conditions at reach scale using genetic algorithms and kriging methods

The combination of current velocity and water depth influences stream flow conditions, and fish activities prefer particular flow conditions. This study develops a novel optimal flow classification method for identifying types of stream flow based on the current velocity and the water depth using a genetic algorithm. It is applied to the Datuan stream in northern Taiwan. Fish were sampled and their habitat investigated at the study site during the spring, summer, fall and winter of 2008-2009. The current velocity, water depth and maps of the presence probability of fish were estimated by ordinary and indicator kriging. The optimal classification results were compared with the classification results obtained using the Froude number and empirical methods. The flow classification results demonstrate that the proposed optimal flow classification method that considers depth-velocity and optimally identified criteria for classifying flow types, yields a current velocity and water depth of 0.32 (m/s) and 0.29 (m), respectively, and classifies the flow conditions in the study area as pool, run, riffle and slack. The variography results of the current velocity and the water depth data reveal that seasonal flows are not spatially stationary among seasons in the study area. Kriging methods and a two-dimensional hydrodynamic model (River 2D) with empirical and optimal flow classification methods are more effective than the Froude number method in classifying flow conditions in the study area. The flow condition classifications and probability maps were generated by River 2D, ordinary kriging and indicator kriging, to quantify the flow conditions preferred by Sicyopterus japonicus in the study area. However, the proposed optimal classification method with kriging and River 2D is an effective alternative method for mapping flow conditions and determining the relationship between flow and the presence probability of target fish in support of stream restoration.