DOW CORNING 1-2577 Conformal Coating as an efficient diffusion material for cathode in the microbial fuel cell

In this study, DOW CORNING 1-2577 Conformal Coating was proposed for the cathode diffusion layer of the microbial fuel cell (MFC). In MFCs, stainless steel mesh cathodes using DOW CORNING 1-2577 Conformal Coating/carbon as the diffusion layer and two poly (dimethylsiloxane) (PDMS)/carbon diffusion layers and carbon cloth cathode with four poly (tetrafluoroethylene) (PTFE) diffusion layers were constructed for comparison. Under the same operational condition, the MFCs with the DOW CORNING 1-2577 Conformal Coating/carbon diffusion layer produced the maximum power density of 1585±52 mW·m^-2, compared with those using poly (tetrafluoroethylene) (PTFE) diffusion layers (1421±45 mW·m^-2) and poly (dimethylsiloxane) (PDMS)/carbon diffusion layers (1353±49 mW·m^-2). The DOW CORNING 1-2577 Conformal Coating could be an alternative for the diffusion layer construction in the MFC due to its remarkable performance and much simple construction procedure.     

山东省近10年对流层NO2柱浓度时空变化及影响因素

利用OMI卫星对流层NO2柱浓度产品研究了近10年山东省NO2时空格局及影响因素,结果表明: 对流层NO2柱浓度波动较大,10年柱浓度年均值增幅为28.5%,其中2011年浓度最高;对流层NO2柱浓度空间变化显著,2005~2009年四、五级高值仅出现在经济发达的内陆城市, 2010~2012年四、五级高值范围显著扩大至中西部大范围地区,尤以2011年最为严重, 2013~2014年,四、五级高值范围呈逐步缩小趋势; 夏季丰富的降水对NO2具有显著湿沉降作用;山东省近10年地区生产总值不断攀升、机动车保有量大且增幅快、秸秆焚烧火点个数多,这些人为排放是对流层NO2柱浓度升高的主要影响因素.     

ERT技术界定卫生填埋场边界的试验研究

界定卫生垃圾填埋场边界有助于场地环境的维护和管理,采用电阻率二维层析成像技术中的3种装置排列(测深、温纳、偶极-偶极)对高阻体上表面特征进行试验模拟,并通过电阻率二维层析成像技术对垃圾填埋场边界的电性特征进行研究,在此基础上开展了现场勘查. 结果表明:在由测深和温纳2种装置排列所得到的二维反演图像中,高阻体的上表面与高阻区相切,误差达到25%,表明2种排列不能进行精确定位;而偶极-偶极的反演图像中高阻体的上表面在低阻区与高阻扩散末端的分界点上,反演精度较高,误差在5%以内.      

福建洛阳江口红树林湿地恢复对蟹类密度的影响

底栖动物尤其是蟹类对红树林湿地生态系统的生态功能恢复有重要意义,研究检验不同红树林种类及林龄和郁闭度是否对蟹类分布情况存在显著影响。从福建洛阳江口红树林湿地动态变化对蟹类密度的影响可以看出：不同植被类型对蟹类密度的影响达到极显著水平。光滩与成熟的秋茄（Kandelia candel）,桐花树（Aegiceras corniculatum）和白骨壤（Avicennia marina）之间有显著性差异（P〈0.05）,而桐花树、秋茄、白骨壤之间无显著性差异（P〉0.05）。在不同红树林树种和林龄2因素对蟹类密度的影响的双因素分析中：树种、林龄、树种和林龄间互作均对蟹类密度的影响达到极显著水平;在不同红树林树种和郁闭度2因素对蟹类密度的影响的双因素方差分析中：树种对蟹类密度的影响达到极显著水平,郁闭度对蟹类密度的影响达到显著水平;树种和郁闭度之间互作对蟹类密度的影响不显著。     

基于马尔可夫随机场的人群密度监测技术

针对目前人群密度估计和人群统计方法的不足,提出基于马尔可夫随机场的人群密度监测技术,将这一方法归纳为两个主要步骤,并详细阐述了其计算原理;讨论存在严重遮挡情况下,通过给定域值,如何将其实际应用于公共场所人群聚集风险管理中的方法.     

岩石破坏失稳的声发射响应与损伤定量表征研究

为了探索在外载荷作用下岩石的损伤演化规律及声发射响应特征,实现损伤程度的定量表征,以标准岩石试件为研究对象,采用RMT-301岩石力学试验系统和DS5-8B全信息声发射仪,开展单轴加载条件下岩石破坏全过程的声发射(AE)试验研究,根据声发射参数、声发射源三维定位、声发射能量密度和岩石力学分析表征其破坏形态,再现岩石裂隙孕育、发展和贯通过程,揭示岩石破坏规律、能量密度分布特征、裂隙空间演化和AE时序参数;以时间为中间变量,建立声发射累计振铃计数和应力、应变及损伤变量的耦合关系;基于岩石损伤演化方程,进一步建立声发射累积能量和应力、应变的定量模型。研究结果对揭示岩石破坏机制、区分岩体强度具有指导意义,为矿山煤岩动力灾害的预测预警提供一定理论支撑。     

商业类建筑人员密度统计分析与建模

对文献中商业类建筑人员密度的实地调查数据进行了整理分类,用统计方法研究了建筑面积、商业类型(经营形式和性质)、城市类型(所在城市经济水平)以及营业时期对人员密度的影响.结果表明,建筑面积与人员密度不存在明显的线性关系,而商业类型、城市经济水平以及营业时期对人员密度的影响较大;超市、服装类建筑的人员密度高于百货商场和家具建材类建筑,商业建筑人员密度随城市经济水平增长而降低.利用广义线性回归模型,以商业类型、城市类型和营业时期为解释变量初步建立了商业类建筑人员密度的预测模型.     

A Fast Method for Monitoring Foliage Density in Single Lower-canopy Trees

A subjective visual assessment of foliage density is the mostwidely used rapid method of determining forest health. Forthese assessments to be ecologically meaningful they must bereliable (have low inter- and intra-observer variability) andreadily relate to a measure of physiological or physicalstress. A simple rapid method for assessing percent foliagedensity in lower stature trees is described. This method haslow inter-observer variability (standard deviation betweenobservers=8.6%) and therefore, minimizes the risk ofconfounding the effects of different observers with genuinechanges in density. The percentage changes in this measure offoliage density correlate well with percentage changes inbiomass, allowing a ready interpretation of observed changes.The technique does not specifically identify the cause of themeasured changes, however, with appropriate additionalmeasures this problem may be overcome.     

Utilization Characteristics and Importance of Woody Biomass Resources on the Rural-Urban Fringe in Botswana

This article examines the utilization characteristics and importance of woody biomass resources in the rural-urban fringe zones of Botswana. In the literature for Africa, attention has been given to the availability and utilization of biomass in either urban or rural environments, but the rural-urban fringe has been neglected. Within southern Africa, this neglect is not justified; the rural-urban fringe, not getting the full benefits available in urban environments in Botswana, has developed problems in woody biomass availability and utilization that require close attention. In this article, socioeconomic data on the importance of woody biomass in the Batlokwa Tribal Territory, on the rural-urban fringe of Gaborone, Botswana, were collected together with ecologic data that reveal the utilization characteristics and potential for regrowth of woody biomass. The analysis of these results show that local woody biomass is very important in the daily lives of communities in the rural-urban fringe zones and that there is a high level of harvesting. However, there is no effort in planning land use in the tribal territory to either conserve this resource or provide alternatives to its utilization. The future of woody biomass resources in Botswana’s rural-urban fringe is uncertain. The investigators recommend that a comprehensive policy for the development of the rural-urban fringe consider the importance of this resource. The neglect of this resource will have far-reaching implications on the livelihoods of residents as well as the environment in this zone.     

太湖流域近地表主要温室气体本底浓度特征

根据2003年1月-2005年6月太湖流域近地表大气中主要温室气体CO2、CH4和N2O本底浓度的监测资料,研究了该流域近地表大气主要温室气体浓度的变化特征.结果表明,在观测时段内,该流域近地表大气CO2浓度呈上升趋势;CH4浓度呈逐年递减趋势;N2O浓度呈先减后增趋势.3种气体主要与人类活动、工农业生产和交通运输业发展有关,CO2浓度的季节变化明显,冬春季高,夏秋季低,最高值在12月,最低值在8月;CH4浓度由春至夏升高,由夏至秋至冬递减,最高值在7月,最低值在2月;N2O浓度没有明显的季节变化,它们主要受源汇强度变化影响.CO2浓度的日变化基本呈双峰态,是源汇强度变化和边界层稳定程度相互作用的原因,CH4浓度无明显日变化规律,N2O浓度日变化中的最高值总体呈现是夏、秋、春至冬逐渐延迟的状态.