基于流媒体技术的远程教育平台的设计与实现

流媒体技术采用流式传输的方式在Internet／Intranet播放的媒体格式，其数据流随时传送随时播放，缩短了启动延时，降低了对系统缓存容量的需求，极大地减少了用户的等待时间，因此广泛应用于网络教育、网络电台、视频点播、收费播放等方面。文中主要介绍了流媒体技术的特点、原理，进一步阐述了用于在局域网和Internet中传送流式多媒体内容的开发工具windows media，给出了一种利用Windows media流媒体技术构建远程教育系统的具体方案，很好的解决了音频，视频信息的传送问题和数据间的同步问题。     

特定生态系统对水源地水质改善的研究

通过构建水生动物-人工介质新型生态系统来研究太湖水源地水质改善效果.中试试验结果表明,对比3d和7d的水力停留时间(HRT),当HRT:7d,系统对TN、NO2--N、NO3--N、TP、PO4--P的平均去除率可分别达到79.00%、63.46%、14.57%、67.43%、35.81%;对比空白池,TN、NO2--N、NO3--N、TP、PO4--P的平均去除率仅为9.67%、7.09%、1.30%、9.92%、7.04%.通过该系统中水生动物的吸收和人工介质上微生物降解的协同作用,使得氮磷类污染物的去除效果明显.可见,水生动物-人工介质生态系统对改善太湖水源地水质有良好的效果,对构建安全的水源地生态系统具有积极的意义.     

低渗透介质中轻非水相流体迁移转化规律

本文利用COMSOL软件建立轻非水相流体(LNAPL)纵向迁移转化模型,采用有限单元法进行求解,预测污染物分布规律,并利用局部分析法进行参数敏感性分析.结果表明,大部分LNAPL会在水面以上聚集形成高的质量分布峰值区域,少部分克服毛细压力向下迁移,在自由相迁移范围内,其溶解相浓度达到或接近饱和溶解度;当顶部污染源消失后...     

三层滤料高速过滤应用于再生水生产的研究

试验在传统混凝—沉淀—三层滤料过滤工艺的基础上,通过对滤料级配的改进,将三层滤料高速过滤工艺应用于再生水的生产,对其可行性进行分析研究。结果表明:在最佳工艺条件下出水浊度的去除率可达97.5%～98.5%,COD去除率在43%左右。同时研究发现,在高速过滤条件下,通过絮凝剂在滤床中发挥的微絮凝作用,可以起到良好的除污效果且出水水质稳定。     

Elite cues,media coverage,and public concern: an integrated path analysis of public opinion on climate change, 2001–2013

To analyze the factors affecting US public concern about the threat of climate change between January 2002 and December 2013, data from 74 separate surveys are used to construct quarterly measures of public concern over global climate change. Five factors should account for changes in levels of concern: extreme weather events, public access to accurate scientific information, media coverage, elite cues, and movement/countermovement advocacy. Structural equation modeling indicates that elite cues, movement advocacy efforts, weather, and structural economic factors influence the level of public concern about climate change. While media coverage exerts an important influence, it is itself largely a function of elite cues and economic factors. Promulgation to the public of scientific information on climate change has no effect. Information-based science advocacy has had only a minor effect on public concern, while political mobilization by elites and advocacy groups is critical in influencing climate change concern.     

论代表性的涵义及工业废水重点源采样方案的设计原则

数据代表性是指监测结果在表征被监测对象特性时所能达到的真实程度;样品代表性是指局部体现整体时所能达到的真实程度。加密监测是重点原调查的质量基础,不能简化行事。监督性监测中,通过测定流量比例混合样来获取总量控制所必需的漉量加权平均值浓度数据,并以此来减小工作量。为满足浓度控制需要,时间—浓度确定型废水的峰浓度样应单独测定。     

Achieving sustainable lifestyles or encouraging a counter-reflexivity: exploring motivations for sustainability in a mediated risk society

Ulrich Beck's World Risk Society is becoming an increasingly relevant analysis of contemporary human/environment interaction. However, with this said, Beck's observations remain broad and significantly lacking empirical evidence. This paper explores the relationship between sustainable lifestyles and assertions of one of Beck's central ideas, the emergence of a reflexive modernity at the local scale. By empirically examining the motivation of participants for joining a scheme designed to enhance sustainable lifestyles, this paper will progressively outline the way that individuals in a risk society negotiate global images in a local context and what this means for a reflexive modernity. By exposing the complex interaction of global risk imagery and the effect this has on achieving local sustainability, a more realistic understanding of Beck's theoretical assertions can be applied to an increasingly important policy arena.     

Mobilizing environmental sentiment through the media

ABSTRACT

Recent research into the best ways to mobilize people to act on climate change suggests that careful, and relatively positive, emotional framing is critical. However, environmental non-governmental organizations (ENGOs) need to not only mobilize publics, but also attract media coverage. If the media prefers negativity or is skeptical of ENGOs’ emotive appeals, are ENGOs’ emotional frames damaging their ability to gain media attention? Quantitative sentiment analysis is used to identify emotional framing in a targeted case study of 350.org’s public press releases and their subsequent media coverage. The results suggest that appropriate emotional frames for mobilization are not necessarily detrimental to gaining media attention, and that ENGO press releases influence media coverage, when they are used. Several concrete suggestions emerge for how ENGOs might use press releases more effectively, if they seek to influence the media’s emotional tone on climate change.     

饮用水处理厂锰砂滤料对苯酚的吸附性能及影响因素

为了解锰砂滤料对苯酚的吸附性能和影响因素,以生物锰砂滤池运行结束后产生的废料为吸附剂,研究了不同初始pH、温度和溶解氧条件下锰砂滤料对苯酚的吸附性能,通过吸附动力学模型和吸附等温线模型研究其吸附规律。结果表明:锰砂滤料对苯酚的吸附过程符合内扩散动力学模型和Temkin吸附等温线模型,每单分子层吸附,吸附效果主要受苯酚扩散速率影响。通过对吸附等温线n值的计算发现,锰砂滤料容易吸附苯酚。pH对锰砂滤料去除苯酚的影响最大,初始pH为3.0时,苯酚可完全去除,随着初始pH的升高,苯酚的去除率逐渐减小。中性条件下,溶解氧浓度对苯酚的吸附作用影响不大,低温时可通过增加锰砂滤料投加量提高苯酚去除率,每增加1.5倍锰砂滤料,苯酚去除率约增加20个百分点。锰砂滤料可应用于地下水中的苯酚去除,达到废料再利用,不产生二次污染。     

隔膜压滤机滤室最优空腔厚度

利用UG软件对隔膜压滤机滤室内流体进行三维建模,导入Gambit中进行网格划分及边界条件的设定,结合Fluent选用RNG k-ε湍流模型,采用多孔介质模型模拟隔膜压滤机滤室内固-液两相流分离,得到不同空腔厚度下滤室内流体的体积分数轮廓图、压强云图,得出滤饼含水率与空腔厚度大小的关系。实验结果表明,模拟和实验结果具有较好的一致性。在压滤机滤室空腔厚度为12 mm时,滤饼含水率为48%,每天污泥处理量为102 t,隔膜压滤机工作效率最高。