扬沸火灾监测预报方法研究（2）——实验分析

实现在大环境背景噪声条件下对扬沸前兆微爆噪声的识别，是利用扬沸前兆噪声监测预报扬沸火灾的技术关键。本文则在第一部分的理论基础之上，重点了扬沸前兆噪声和典型火灾现场环境噪声的声学特性，从其中寻找出能有效地进行扬沸火灾监测预报的一些特征物理量，为进一步实现在实际火灾现场大环境下利用前兆噪声监测预报扬沸火灾提供了条件。     

纳米零价铁去除磷酸盐机理研究

纳米零价铁(nanoscale zero-valent iron,nZVI)颗粒具有独特核-壳结构,使其具有较强氧化还原特性,比表面积大和表面活性高等特点,因此被广泛用于不同环境介质中多种污染物的去除修复。本研究采用传统的液相化学还原法合成nZVI颗粒并用于去除水溶液中的磷酸盐。通过扫描电子显微镜(SEM)、透射电子显微镜(TEM)和X射线衍射仪(XRD)表征nZVI颗粒的性质。实验研究了nZVI投加量、PO3-4初始浓度、溶液初始pH值对nZVI去除PO3-4效率的影响及微米零价铁(micro-ZVI)和nZVI去除PO3-4的对比。实验结果表明,当PO3-4初始浓度为20mg/L时,随着nZVI投加量从200mg/L增加到1000mg/L,PO3-4去除效率从32.94%上升到90.17%;当nZVI投加量为600mg/L时,随着PO3-4初始浓度从10mg/L增加到100mg/L,PO3-4去除效率从87.33%下降到45.77%;当nZVI投加量为600mg/L且PO3-4初始浓度为20mg/L,溶液pH分别为3和4时,PO3-4去除效率分别为83.63%和92.36%;nZVI和mZVI投加量均为600mg/L且PO3-4初始浓度为10mg/L,nZVI的PO3-4去除率(87.33%)是mZVI(8.86%)的9.86倍。研究结果表明,nZVI能够高效去除水体中的磷酸盐,主要去除机理是吸附和化学沉淀的双重作用。     

施工现场工作环境安全评价

随着经济的发展,人们对于安全,包括工作环境的安全的要求越来越高.目前对工作环境安全性的评价,一是采用定性的方法,二是依靠历史统计数据,对危险性进行量化.主要对象是人机环境中"机"的因素.本文利用实验心理学的有关理论,尝试通过人对环境的生理、心理反应建立评价工作环境安全性的方法.该方法应用于竹脚手架、金属脚手架的安全性比较研究的实验,分析结果显示它能够较客观地评价工作环境的安全程度.     

中小企业融资初探

中小企业在我国国民经济中起着越来越重要的作用，如何促进其健康、正常发展具有重要作用．本文着重讨论了中小企业在其发展过程中所遇到的融资困难和可能的融资途径．     

喀拉库里表层沉积物组成的分布特征及其物质来源

喀拉库里地处帕米尔高原东部,整个湖区被中纬度西风带贯穿,湖水主要由冰川融水和夏季降水补给,对气候变化响应敏感,是重建西风气候和冰川环境演变的理想区域,然而对于喀拉库里沉积物的组成和来源还知之甚少。本文以喀拉库里表层沉积物为研究对象,获得了其组成及空间分布特征,进而探讨了其物源及输入方式。根据沉积物粒度、矿物组成及湖水等深线分布,表层沉积物可分为三种类型:第Ⅰ类以细砂粒为主,以高石英和低粘土为特征,分布在近湖岸;第Ⅲ类以分选良好的细粉砂为主,主要分布在深湖区;第Ⅱ类粗、细颗粒混杂,分选性差,位于Ⅰ、Ⅲ类沉积物过渡区域。喀拉库里沉积物的SiO_2含量同粒径呈正相关关系,粒径越大、含量越高;Al_2O_3、Fe_2O_3和K_2O则相反。结合河流泥沙和慕士塔格冰芯中粉尘颗粒的粒度分布及区域气候特征,初步认为深湖区分选良好的细粉砂可能主要来自西风携带的高空粉尘,而近岸细砂是岩石就地物理风化的产物。这些认识对于钻点的选取及沉积序列气候、环境信息的提取具有重要价值。     

基于GAC颗粒污泥厌氧氨氧化EGSB反应器的快速启动

以GAC颗粒污泥为接种污泥研究厌氧氨氧化EGSB反应器快速启动的条件及运行参数。反应器的启动在17 d内完成,总氮容积负荷达到1.62 kg/(m3·d)。采用缩短水力停留时间方式提高反应器负荷,14 d内反应器总氮容积负荷能快速升至1.45 kg/(m3·d),实验结果表明采用低基质浓度和缩短水力停留时间方式更利于厌氧氨氧化反应器的启动。第18~21 d平均产气速率为1.1 L/h,用气相色谱仪对EGSB反应器产生的气体进行分析,N2O、CO2平均体积分数分别为0.8%、0.02%,如何降低气体中N2O的浓度需要进一步研究。     

Individual particle analysis of aerosols collected at Lhasa City in the Tibetan Plateau

To understand the composition and major sources of aerosol particles in Lhasa City on the Tibetan Plateau (TP), individual particles were collected from 2 February to 8 March, 2013 in Tibet University. The mean concentrations of both PM_2.5 and PM₁₀ during the sampling were 25.7 ± 21.7 and 57.2 ± 46.7 μg/m³, respectively, much lower than those of other cities in East and South Asia, but higher than those in the remote region in TP like Nam Co, indicating minor urban pollution. Combining the observations with the meteorological parameters and back trajectory analysis, it was concluded that local sources controlled the pollution during the sampling. Transmission electron microscopy (TEM) combined with energy-dispersive X-ray spectra (EDS) was used to study 408 particles sampled on four days. Based on the EDS analysis, a total of 8 different particle categories were classified for all 408 particles, including Si-rich, Ca-rich, soot, K-rich, Fe-rich, Pb-rich, Al-rich and other particles. The dominant elements were Si, Al and Ca, which were mainly attributed to mineral dust in the earth's crust such as feldspar and clay. Fe-, Pb-, K-, Al-rich particles and soot mainly originated from anthropogenic sources like firework combustion and biomass burning during the sampling. During the sampling, the pollution mainly came from mineral dust, while the celebration ceremony and religious ritual produced a large quantity of anthropogenic metal-bearing particles on 9 and 25 February 2013. Cement particles also had a minor influence. The data obtained in this study can be useful for developing pollution control strategies.     

低碳经济下农作物秸秆能源利用需求性分析

本文介绍了农作物秸秆能源利用的几个途径,从能源短缺、环境压力、秸秆过剩数量压力以及发展农村经济等方面分析了在低碳经济下秸秆能源利用的需求性和紧迫性,提出应该加强秸秆能源利用技术研究,大力推广秸秆能源利用。     

近47年中国夏季日降水变化特征分析

以中国596个气象台站1961~2007年的夏季逐日降水资料为基础,分析了近47 a中国夏季降水长期趋势和年代际变化特征。采用面积加权平均法得到夏季全国和8个区的降水量、降水频率、降水强度序列。按小雨、中雨、大雨及暴雨降水强度分类,探讨了不同强度降水在我国降水变化中的贡献。结果表明：中国总体夏季除降水频率呈减小趋势外,降水总量、降水强度都呈增加趋势;西北西部在8个区域中的变化相对显著。降水量的增加是小雨级别降水频率和中雨以上级别降水强度增加共同作用的结果;东北、华北、西北东部降水减少主要是小雨降水频率减少的结果;长江中下游和华南降水量增加主要是大雨、暴雨降水频率和暴雨降水强度增加共同作用的结果;西南降水减少主要是小雨降水频率减少的结果。各区及全国夏季降水量、降水频率和降水强度大多在90年代有所增大,在2000年后又有所减小。与1970年代末的气候跃变相对应,各区及全国降水频率、降水强度的跃变均发生在1970年代末或1980年代初。〖     

The current municipal solid waste management situation in Tibet

The Tibetan Plateau has an average altitude of more than 4,000 m. The total area of Tibetan Plateau is 2,400,000 km2, which occupies 25% of the area of China. Due to the high altitude, the environment has low atmospheric pressure, low oxygen content, and low temperature, and is also fragile. Investigations concerning MSW generation and characteristics, MSW management, collection and transportation, and treatment and disposal of MSW covered four representative cities, including the urban areas of Lhasa city, Shigatse, Nedong of Lhoka and Bayi of Nyingtri. The results show that MSW generation in the urban areas of Lhasa city and Tibet were 450 t/d and 3,597 t/d, respectively, in 2006. However, accelerated economic development and flourishing tourism caused by the opening of the Qinghai-Tibet Railway (QTR) have greatly increased solid waste generation to a new high. It is predicted that MSW generation in Tibet will reach 4,026 t/d in 2010 and 4,942 t/d in 2020. MSW management and disposal lag behind MSW generation due to a number of factors such as equipment shortage, insufficient maintenance, exhaustion of waste treatment capacity and low recycling efficiency. Still, MSW in most areas is dumped in the open with no controls. Because no appropriate collection and treatment systems for leachate and landfill gas exist, untreated leachate is discharged directly into the environment, causing serious secondary pollution. Some suggestions on improving the MSW management system are presented in this paper.