大气中SO2排放连续监测可行性探讨

中国是世界上ＳＯ２排放的大户,如不加以严格控制,将成为制约社会经济发展的重要因素之一,因此对上海市ＳＯ４重点的污染源,提出了连续监测的方案,探讨了其可行性,并从技术原理和连续监测系统的管理等方面进行了分析,这方案基本符合国家对“两控区”重点城市安装ＳＯ２在线监测系统的要求,是迈向国际化大都市环境管理的有力举措。     

污染源连续监测系统的应用与发展

阐述了污染源连续监测系统（简称CEMS）在国内外的发展和应用。通过对各种CEMS特性的分析，并在原理、分析方法、监测对象、日常操作维护及费用成本上加以比较，指出现场式CEMS是发展方向，适合于未安装过CEMS的火电厂。同时，作为现有CEMS的改进，可选用稀释抽取式CEMS。     

How resources and encounters affect the distribution of foraging activity in a seed-harvesting ant

We examined how the foraging ecology of the seed-harvesting ant Messor andrei depends upon the distribution of resources and the presence of conspecifics. Bait experiments showed that colonies can recruit to high-density patches of seeds. However, at the seasonal scale, natural resource distribution did not affect the distribution of foraging activity. We conducted the study in years of high rainfall and thus seed availability may not have been a limiting factor. Colonies always preferred to forage in areas closer to their nest, which may reduce travel time between the nest and foraging sites. On a day-to-day scale, encounters between neighboring colonies at a site increased the probability that colonies would return to forage at that site; this was true both for natural and experimental encounters. In the summer, this resulted in colonies foraging at the sites of intraspecific encounters on more days than in areas where no encounter had occurred. Encounters between colonies included fighting, and there was little overlap between the foraging areas of neighboring colonies: both results suggest that one function of encounters is to defend foraging space. The high probability of return to the site of an encounter between colonies suggests that encounters may have a second function: to indicate the presence of resources. Received: 28 June 1999 / Received in revised form: 12 October 1999 / Accepted: 16 October 1999     

SIEMENS烟气连续监测系统在电子束脱硫装置中的应用

本文介绍了SIEMENS烟气连续监测系统的性能及其在电子束辐照烟气工业化试验装置中的应用,对其工作特点和实际运行情况进行了分析。     

汉江上游十大洪水气象特征分析

本文分析了安康大洪水的气候分布和气象成因,讨论了水文气象接口问题,指出进行气象洪水预报是可能的。     

Indoor radon periodicities and their physical constraints: a study in the Coimbra region (Central Portugal)

Indoor radon activities were measured during a period of 6 months, as well as several physical environmental variables (temperature, pressure, humidity and rainfall). The location was a small room at an administrative building of the University of Coimbra, usually undisturbed by human activities and situated over bedrock of low-uranium Triassic red sandstones. A low average activity of radon was observed (36 Bq m⁻³), however showing a very well marked daily periodicity (10 ± 5 Bq m⁻³), with maximum values occurring more frequently between 9 and 10 a.m. Daily variations are shown to have no relation with earth tides, and their amplitudes exhibit a significant correlation with outdoor temperature; no dependence on barometric pressure was found. Rainfall disturbs the observed daily radon cycles through a strong reduction of their amplitude, but has no effect on the long-term variability of the gas concentration.     

A chemostat system for investigating pesticide biodegradation in continuous mixed bacteria cultures originating from surface water

To be able to predict the degradation (rate) of organic chemicals (e.g. pesticides) in the field, knowledge of the environmental conditions that are of influence on the degradation process are of importance. In the present study an experimental system is described which is used to study the degradation of organic pollutants in mixed bacteria cultures originating from surface water. With this system the degradation of compounds can be followed for relatively long experimental periods (months). In addition, it is possible to vary different environmental parameters in order to investigate their influences on the degradation of the chemical. These preliminary experiments show that growth and ‘composition’ of the bacteria culture have comparable patterns in parallel experiments. The first order degradation rate constant for the test compound dichloran, as calculated from these experiments under these circumstances, is about 0.002 h⁻¹.     

秦岭安河矿区地表水、沉积物重金属污染研究

以秦岭安河铅锌矿开采区和选矿区为研究范围,通过现场调查和系统采集地表水、沉积物样品,借助原子吸收分光光度计测试样品中Cu、Pb、Zn、Cd、Cr 5种重金属全量,并对不同重金属的形态含量进行了测定,综合分析了各类重金属在地表水、沉积物中的富集迁移规律,实现了重金属污染程度的综合评价。结果表明:矿区沟道地表水、沉积物已受到严重的重金属污染,重金属元素自上游到下游呈累积现象。下游地表水重金属含量超出农田灌溉用水水质要求。中游、下游沉积物重金属污染指数达到Ⅲ级污染,主要污染物为Pb、Zn。沉积物中重金属的有效态所占比例较高,对周围环境直接威胁大,显示出外源重金属直接注入的特征。     

Experimental continuous sludge microwave system to enhance dehydration ability and hydrogen production from anaerobic digestion of sludge

Dehydrating large amounts of sludge produced by sewage treatment plants is difficult.Microwave pretreatment can effectively and significantly improve the dewaterability and hydrogen production of sludge subjected to anaerobic digestion. The aim of this study was to investigate the effects of different microwave conditions on hydrogen production from anaerobic digestion and dewaterability of sludge. Based on an analysis of the electric field distribution, a spiral reactor was designed and a continuous microwave system was built to conduct intermittent and continuous experiments under different conditions. Settling Volume, Capillary Suction Time, particle size, and moisture content of the sludge were measured. The results show that sludge pretreatment in continuous experiments has equally remarkable dehydration performance as in intermittent experiments; the minimum moisture content was 77.29% in the intermittent experiment under a microwave power of 300 W and an exposure time of 60 sec, and that in the continuous experiment was 77.56% under a microwave power of 400 W and an exposure time of 60 sec.The peak measured by Differential Scanning Calorimeter appeared earliest under a microwave power of 600 W and an exposure time of 180 sec. The heat flux at the peak was 4.343 W/g, which is relatively small. This indicates that microwave pretreatment induced desirable effects. The maximum yield of hydrogen production was 7.967% under the conditions of microwave power of 500 W, exposure time of 120 sec, and water bath at 55°C. This research provides a theoretical and experimental basis for the development of a continuous microwave sludge-conditioning system.     

连续流动分析法测定水质中高锰酸盐指数的方法研究

研究建立采用连续流动分析法测定水中高锰酸盐指数的分析方法,方法的检出限为0.04 mg/L,测定范围为0.16-10.0 mg/L。实验表明测得的数据与采用国家标准方法测得的数据有较好的一致性,并且已应用于实际样品测定,结果令人满意。具有操作简单、灵敏度高、分析速度快、稳定性高且易于实现自动化分析。