城中村：都市环境中的黑点

改革开放以来,广东城市化的进程不断加快,到1996年底,广东城市化水平已达30.42％,比全国平均水平高出七个百分点,在其间,除了城市的质量有了很大提高外,城市的向外扩张和农村地域转变为城市化地区,是本阶段城市化进程的重要特征。目前,广东农村城市化的途径存在两种:一种是农村通过自办或引进非农产业改变本地经济结构而走向城市化,另一种是指农村被城市征用土地而“被城市化”。城市的发展,必然带来用地向外的扩展,因此,城     

城市空气中多环芳烃定量测定方法

本文发展了一种对城市空气中多环芳烃(PAH)定量测定的方法。该方法可以用极少量溶剂,相当快地完成测定工作。     

对德国、丹麦有害废物处置技术的考察

德国和丹麦对有害废物处理处置技术大体上有四个方面，即废物的预处理、焚烧技术、填埋技术和有机废物产生沼气。     

The role of socio-economic data in food needs assessment and monitoring

This paper reviews six case studies examined as part of a project to review targetting methodologies employed by non-government organisations in Africa during the 1984-6 food crisis. Most agencies have not yet fully evaluated the role of data in informing policy decisions during their respective emergency programmes. The case studies presented reflect a wide variety of approaches to targetting emergency food aid that are based largely on the use of 'socio-economic' data. The recent emergency relief operations in Africa seem to indicate a change in relief agencies' approaches to the assessment and monitoring of needs of the affected populations. Earlier dependance on nutritional data has given way to an increasing reliance on the use of socio-economic indicators. There was a wide variation in the case studies of the type of indicators collected and utilised in needs assessment and monitoring. There were those who relied almost exclusively on nutritional data to target resources during the 1984-86 African crisis, and others whose experiences during that period lead them to attach more weight to socio-economic data. Other agencies appear to have recognised the problems of relying solely on nutritional data to target food aid during their 1984–86 emergency programmes, and thus more or less abandoned classical anthropometric surveys in their needs assessment and monitoring methodologies during this period. Thus nutritional data has a less significant role in the decision making process than previously had been the case.     

The Spitak (Armenia, USSR) Earthquake: Residential Building Typology and Seismic Behaviour

The 1988 earthquake in Armenia was the most serious seismic disaster since the 1976 earthquake in Tangshan, China. At least 25,000 people lost their lives in a tremor of moderate magnitude and the USSR suffered a loss of more than 2.5 per cent of 1988's GDP. Research at the Martin Centre on the effects of earthquakes on human lives has shown an increase in global earthquake mortality rate, despite the well known improvements in some countries. The Armenian disaster was a warning to all of us concerned with natural or man-made disasters. Areas of potential high hazard are pointed out for the sub-Caucasian region. Construction practices similar to those in Armenia are certainly found in many other parts of the world, with some regional variations, and the fast assimilation of the lessons is an important target. The structural characteristics of all the residential building types existing in the affected area are presented in terms of their seismic vulnerability. Vulnerable points are discussed with a view to low cost interventions that will drastically improve the seismic safety of new buildings.     

用广义λ—分布拟合空气污染数据

广义λ-分布是一个四参数可变通的概率模型,包括多种单变量分布,这一模型可用于表示空气污染浓度的频率分布。本文采用土耳其安卡拉每日的烟和SO_2监测数据,来证明广义λ-分布具有良好的拟合性质。这里还讨论了与分位数估计和拟合优度有关的一些结果,并与经典对数正态分布进行了比较。     

Characterization of microbial communities from coastal waters using microarrays

Molecular methods, including DNA probes, were used to identify and enumerate pathogenic Vibrio species in the Chesapeake Bay; our data indicated that Vibrio vulnificus exhibits seasonal fluctuations in number. Our work included a characterization of total microbial communities from the Bay; development of microarrays that identify and quantify the diversity of those communities; and observation of temporal changes in those communities. To identify members of the microbial community, we amplified the 16S rDNA gene from community DNA isolated from a biofilm sample collected from the Chesapeake Bay in February, 2000. The resultant 75 sequences were 95% or more similar to 7 species including two recently described Shewanella species, baltica and frigidimarina, that have not been previously isolated from the Chesapeake. When the genera of bacteria from biofilm after culturing are compared to those detected by subcloning amplified 16S fragments from community DNA, the cultured sample exhibited a strong bias. In oysters collected in February, the most common bacteria were previously unknown. Based on our 16S findings, we are developing microarrays to detect these and other microbial species in these estuarine communities. The microarrays will detect each species using four distinct loci, with the multiple loci serving as an internal control. The accuracy of the microarray will be measured using sentinel species such as Aeromonas species, Escherichia coli, and Vibrio vulnificus. Using microarrays, it should be possible to determine the annual fluctuations of bacterial species (culturable and non-culturable, pathogenic and non-pathogenic). The data may be applied to understanding patterns of environmental change; assessing the health of the Bay; and evaluating the risk of human illness associated with exposure to and ingestion of water and shellfish.     

原子吸收法测定矿化水中的银

<正> 由于检出限低,准确度高和分析速度快,在测定银的分析方法中原子吸收光谱法得到广泛应用。例如,在低矿化天然水中银的相对检出限为0.03μg/L。用无火焰原子吸收法直接测定高矿化水中的银有困难,因为基体效应大。消除此效应的最有效的方法是利用炉温稳定的平台技术。实现     

菲律宾制糖工业废水的厌氧处理

1.前言菲律宾制糖工业在国民经济中占有重要地位,甘蔗种植面积达50万公顷,在1983～84年度的制糖季节里,全国41个糖厂的蔗糖产量为230万吨。在粗糖生产中的主要副产物有:(1)糖蜜,通常用来生产酒精;(2)蔗渣,通常用来作燃料或者造纸;(3)滤泥,通常用来加工成有机肥料。在粗糖、精制糖与酒精的生产过程中要产生大量废水,通常都将这类废水排入工厂附近的河流或港湾中,常常给这些水域造成难以承受的环境污染。菲律宾国家污染控制委员会最近发布命令指出,不久的将来将颁布控制地表水污染的法规。为此,菲律宾工业产生的废水必须进行处理才能向外排放,有些糖厂已经设置了废水处理设施。传统的废水处理装置通常包括曝气池或贮水塘,然而,因为能源耗用量大,曝气系统的费用很高。