基于动土压力响应特性的黄土滑坡振动台试验研究∗

为了探讨地震作用下动土压力沿高程和滑面的响应规律,通过大型振动台实验输入X向和Z向地震波,输入幅值逐级增大直到边坡破坏,对沿滑面和沿高程的5个土压力传感器的动土压力峰值分布规律进行分析,并利用基于小波变换的能量提取工具对加载X向和Z向的EL波进行分解,分析其在不同频带的动力响应特性,并进行了加速度峰值分析与动土压力峰值的组合响应分析。研究结果表明:(1)土压力沿高程和滑面都呈现非线性增加的趋势,加载X向地震波对滑面土体应力影响较为显著,而加载Z向地震波对坡顶面附近土体应力影响较为显著,且加载Z向地震波土压力沿高程放大趋势比加载X向地震波更明显;(2)输入加速度峰值0.6g时,滑体开始向下滑动,贯通破裂面的产生和动土压力峰值以及加速度峰值同时突变可作为边坡破坏的依据;(3)使用基于小波变换的能量提取工具对各频段的能量进行提取,发现第一频段的能量占比在95%以上,说明第一频段内土体响应最为剧烈,黄土边坡对地震波运动过程中高频部分具有"滤波作用",因此进行防护设计时应把这一现象作为设计的考虑因素之一。     

Employees' surface acting in interactions with leaders and peers

Surface acting has been widely studied in organizational research owing to its impact on organizational behaviors and outcomes. Past research almost exclusively has focused on employees' interactions with external parties such as customers, clients, and patients. This study sought to extend this literature by examining the effects of employees' surface acting in interactions with parties internal to the organization (i.e., leaders and peers). Data were collected from 40 work groups (129 focal participants, 40 leaders, and 40 peers) from a large real estate agency company located in Beijing, China. Results showed that employees' surface acting influenced various emotional, relational, and behavioral outcomes. In addition, the present findings revealed that the consequences of employees' surface acting differed across leaders versus peers. Copyright © 2015 John Wiley & Sons, Ltd.     

公众对煤矿区地质灾害的感知与适应行为研究

煤矿区的地质灾害较为常见,而且随着开采时间的推移地质灾害问题日益严重。公众对煤矿区地质灾害的感知与适应行为直接与他们的生命财产相关,同时还关系到政策法规的制定。通过对煤矿区公众的问卷调查发现,公众对地质灾害的严重程度和灾害原因感知是比较准确的,但仍有相当比例的公众选择采取无效的紧急适应行为,有近三分之一的公众没有考虑采用迁移的适应行为。公众对煤矿区地质灾害适应行为的背后涉及利益相关方的博弈。     

5氟尿嘧啶对蛋白核小球藻和羊角月芽藻生长及叶绿素含量的影响

近年来,抗癌药的环境污染特征及其生态风险引起了广泛关注。为获取典型抗癌药5氟尿嘧啶的基础生态毒性数据,以蛋白核小球藻(Chlorella pyrenoidosa)和羊角月芽藻(Selenastrum capricornutum)为受试生物,考察了5氟尿嘧啶对2种绿藻的生长和叶绿素含量的影响。结果表明,5氟尿嘧啶对蛋白核小球藻和羊角月芽藻的生长具有抑制作用,随着暴露浓度升高,细胞生长抑制率增强。5氟尿嘧啶对2种绿藻的96 h半数抑制浓度(EC50)分别为450.36 mg·L~(-1)和692.30 mg·L~(-1),属于低毒性物质。暴露96 h后,低浓度5氟尿嘧啶(32 mg·L~(-1))对蛋白核小球藻和羊角月芽藻叶绿素含量有一定的促进作用,高浓度5氟尿嘧啶(32~500 mg·L~(-1))则抑制了2种绿藻的叶绿素含量,且两者具有明显的负相关关系。和叶绿素b相比,叶绿素a对5氟尿嘧啶胁迫更为敏感。     

垃圾渗滤液一体化生化处理工艺研究

垃圾渗滤液水质十分复杂,不仅含有耗氧有机污染物,还含有各类金属离子和植物营养素(氨氮等),工业垃圾渗滤液中还会含有有毒有害的污染物;其中有难以生物降解的萘、菲等非氯化芳香组化合物、氯化芳香组化合物、磷酸酯、邻苯二甲酸酯、酚类化合物和苯胺类化合物等;垃圾渗滤液中含有十多种金属离子,其中的重金属离子会对微生物产生抑制作用;氨氮含量高,C/N比例失调,磷元素缺乏,给生物处理带来一定的难度.本文开发了UASB-GAIA-BAF一体化生化处理工艺,以节约成本,提高垃圾渗滤液中有机物去除率,加快反应速率为目的,对厌氧生物处理、高级氧化处理、固定化生物滤池组合工艺降解垃圾渗滤液进行了初步设计和工程应用.处理工艺具有工艺成熟、投资省、运行费用低、污泥产生量小的优点.     

苏州市主要工业污染物排放强度研究

污染物排放强度反映单位新创造经济价值的环境负荷大小.运用均方差赋权法对苏州市各地区的工业废水量、工业化学需氧量、工业氨氮、工业二氧化硫、工业氮氧化物、工业烟(粉)尘等6种主要污染物排放强度进行评价,结果表明,六种主要污染物排放强度综合评价的全市平均水平为15.08.然后分别计算各地区的污染物排放强度降低潜力,结果表明,主要污染物排放强度减排潜力存在区域间差异.最后提出促进污染物排放强度降低的一些建议.     

Particle size distribution and characteristics of heavy metals in road-deposited sediments from Beijing Olympic Park

Due to rapid urbanization and industrialization, heavy metals in road-deposited sediments(RDSs) of parks are emitted into the terrestrial, atmospheric, and water environment, and have a severe impact on residents' and tourists' health. To identify the distribution and characteristic of heavy metals in RDS and to assess the road environmental quality in Chinese parks, samples were collected from Beijing Olympic Park in the present study. The results indicated that particles with small grain size(150 μm) were the dominant fraction. The length of dry period was one of the main factors affecting the particle size distribution, as indicated by the variation of size fraction with the increase of dry days. The amount of heavy metal(i.e., Cu, Zn, Pb and Cd) content was the largest in particles with small size(150 μm) among all samples. Specifically, the percentage of Cu, Zn, Pb and Cd in these particles was 74.7%, 55.5%, 56.6% and 71.3%, respectively.Heavy metals adsorbed in sediments may mainly be contributed by road traffic emissions. The contamination levels of Pb and Cd were higher than Cu and Zn on the basis of the mean heavy metal contents. Specifically, the geoaccumulation index(I geo) decreased in the order:CdPbCuZn. This study analyzed the mobility of heavy metals in sediments using partial sequential extraction with the Tessier procedure. The results revealed that the apparent mobility and potential metal bioavailability of heavy metals in the sediments, based on the exchangeable and carbonate fractions, decreased in the order: CdZn≈PbCu.     

Sulfide elimination by intermittent nitrate dosing in sewer sediments

The formation of hydrogen sulfide in biofilms and sediments in sewer systems can cause severe pipe corrosions and health hazards, and requires expensive programs for its prevention. The aim of this study is to propose a new control strategy and the optimal condition for sulfide elimination by intermittent nitrate dosing in sewer sediments. The study was carried out based on lab-scale experiments and batch tests using real sewer sediments. The intermittent nitrate dosing mode and the optimal control conditionwere investigated. The results indicated that the sulfide-intermittent-elimination strategy by nitrate dosing is advantageous for controlling sulfide accumulation in sewer sediment. The oxidation-reduction potential is a sensitive indicator parameter that can reflect the control effect and the minimum N/S (nitrate/sulfide) ratiowith slight excess nitrate is necessary for optimal conditions of efficient sulfide controlwith lower carbon source loss. The optimal control condition is feasible for the sulfide elimination in sewer systems.     

饮用水中溴酸盐控制方法和去除技术研究进展

溴酸盐是一种潜在致癌物,通常产生于含溴离子水源水的臭氧消毒过程中,我国和世界卫生组织饮用水标准中规定溴酸盐的最高浓度为10μg/L。重点综述了近7年来溴酸盐生成的控制方法(如优化臭氧投加量、降低溶液pH值、加氨等)以及溴酸盐离子去除技术(如吸附法、还原法、离子交换法、生物法等)的研究进展,并对各种技术的优缺点进行了评述。