硼氢化钾吹气—分光光度法测定污水中硫化物

污水样品用硼氢化钾片剂酸性氢化反应,使硫化物同酸作用转化为Ｈ２Ｓ,并被氢气吹出,以ＮａＯＨ溶液吸收,再用对氨基二甲基苯胺光度法测定。为了应急监测,研制了ＬＳ－１型硫化物快速测试预装置,配用ＤＲ／２０００型便携式分光光度计,可在现场进行了水中硫化物的快速监测。．     

Diffusion pollution from livestock and poultry rearing in the Yangtze Delta,China

BACKGROUND: The Yangtze Delta is one of the most developed regions in China and includes Shanghai, eight cities in Jiangsu province and eight cities in Zhejiang province. Meat consumption in this region has increased with economic growth, and most of the consumed meat is produced locally. The water quality of surface waters has deteriorated in recent years. An example was the huge blue-green algae bloom in Tai Lake in late May 2007, which affected millions of people's daily drinking water. However, animal husbandry is considered to be one of the main pollution sources. METHODS: Pollutants (NH3-N, total phosphorus (TP), and total nitrogen (TN)) excreted by livestock and poultry, and the resultant COD (chemical oxygen demand) and BOD (biochemical oxygen demand), were estimated using two different methods based on different data sets. RESULTS: The number of livestock and poultry has remained stable in the Yangtze Delta over the four years from 1999 to 2002, with the average number of pigs, cattle, sheep and poultry being 21.1 M, 0.4 M, 7.7 M and 597.6 M, respectively. Pollutants in livestock and poultry excreta estimated by Method I were: 0.12 Mt NH3-N, 0.11 Mt TP and 0.29 Mt TN, resulting in COD and BOD of 1.34 Mt and 1.30 Mt, respectively, while the estimations based on Method II were: 0.18 Mt NH3-N, 0.15 Mt TP and 0.40 Mt TN, resulting in COD and BOD of 1.95 Mt and 1.80 Mt, respectively. DISCUSSION: Pollutants excreted annually by livestock and poultry in the Yangtze Delta are estimated to be: 0.17 Mt NH3-N, 0.16 Mt TP and 0.42 Mt TN, giving rise to a COD of 1.86 Mt and a BOD of 1.72 Mt. Approximately 25% of this pollution was estimated to enter water bodies, which means that the annual pollutant load is 43,700 t NH3-N, 39,400 tTP, 104,600t TN with a COD of 465,000 tand a BOD of 430,100 t. Pollutants from animal husbandry were similar in magnitude to those from industrial wastewater. Pigs produced the most pollution, followed by poultry, cattle and sheep. The pollution load from animal husbandry in the Yangtze Delta is about twice the average level of the whole of China. CONCLUSIONS: Domestic wastewater was the main pollution source in the Yangtze Delta, followed by pollution from raising livestock and poultry and from industrial wastewater. The pollution load in Shanghai and Jiaxing were the greatest, followed by 7 cities of Jiangsu province (except Suzhou) and other cities of Zhejiang province and Suzhou. Pigs and poultry produced about 90% of the total pollutants from animal husbandry. RECOMMENDATIONS AND PERSPECTIVES: The local governments, especially in Shanghai and Jiaxing, should focus their attention on the pollution produced by livestock and poulrry. Controlling pollution from pigs and poultry will have the greatest impact in this region. Control of pollution will be facilitated by the development of large-scale livestock and poultry farming units and a shift away from small scale husbandry.     

气相色谱-质谱法测定废酸油渣中的16种多环芳烃

建立了废酸油渣中16种多环芳烃超声萃取、Florisil萃取柱净化、气相色谱-质谱测定的方法.笔者对提取方式、提取剂类型和体积、提取时间和次数、净化方式等进行研究,采用无水硫酸钠分散,二氯甲烷作为提取剂超声40 min,提取液经纯水清洗、离心后取适量有机相经过3 g Florisil萃取柱净化,采用气相色谱-质谱选择离...     

Analysis of motorcycle accidents using association rule mining-based framework with parameter optimization and GIS technology

IntroductionAnalyzing key factors of motorcycle accidents is an effective method to reduce fatalities and improve road safety. Association Rule Mining (ARM) is an efficient data mining method to identify critical factors associated with injury severity. However, the existing studies have some limitations in applying ARM: (a) Most studies determined parameter thresholds of ARM subjectively, which lacks objectiveness and efficiency; (b) Most studies only listed rules with high parameter thresholds, while lacking in-depth analysis of multiple-item rules. Besides, the existing studies seldom conducted a spatial analysis of motorcycle accidents, which can provide intuitive suggestions for policymakers. Method: To address these limitations, this study proposes an ARM-based framework to identify critical factors related to motorcycle injury severity. A method for parameter optimization is proposed to objectively determine parameter thresholds in ARM. A method of factor extraction is proposed to identify individual key factors from 2-item rules and boosting factors from multiple-item rules. Geographic information system (GIS) is adopted to explore the spatial relationship between key factors and motorcycle injury severity. Results and conclusions: The framework is applied to a case study of motorcycle accidents in Victoria, Australia. Fifteen attributes are selected after data preprocessing. 0.03 and 0.7 are determined as the best thresholds of support and confidence in ARM. Five individual key factors and four boosting factors are identified to be related to fatal injury. Spatial analysis is conducted by GIS to present hot spots of motorcycle accidents. The proposed framework has been validated to have better performance on parameter optimization and rule analysis in ARM. Practical applications: The hot spots of motorcycle accidents related to fatal factors are presented in GIS maps. Policymakers can refer to those maps straightforwardly when decision making. This framework can be applied to various kinds of traffic accidents to improve the performance of severity analysis.     

1991年世界地震灾情及地震活动特征

为适应“国际减灾十年活动”的需要,系统整理了1991年世界地震灾情及重要地震。统计结果表明:全世界1991年全年因地震死亡人数为2084人,中国只有一人;受伤人数约6500人,中国将近700人;倒塌房屋约62万间。全年直接经济损失粗略估算,国外2.7～3.2亿美元,国内约3.3亿人民币。对1991年度地震活动特点进行了简要分析。     

Assessing the biodegradation potential of polymers in screening- and long-term test systems

This paper presents a test scheme for assessing the biodegradation potential of polymers, starting with aquatic screening systems (aerobic and anaerobic) and continuing to long-term systems. At the end of the scheme the material has to prove its behavior under the relevant disposal conditions. Aerobic screening was performed mainly under aquatic conditions, but also in soil, using BOD-respirometry. Carbon balances were performed to obtain a better evaluation of the biodegradation potential. Under anaerobic conditions, biodegradation in an aquatic medium was followed by measuring CH₄ and CO₂ production. Polymers not fully degraded in the screening systems were tested in aquarium systems for at least 1 year. Biodegradation was followed by monitoring the DOC released in the water, mass loss, and microbial growth on the samples and in the water as well as via FTIR spectroscopy and SEM pictures. Results are presented for the polymers PHB, PHBV, PCL, Mater-Bi AI05H and ZF03U, and Bioceta. By combining the data from the screening with the aquarium system, a good picture of the degradation behavior of the polymers is obtained.Paper presented at the Bio/Environmentally Degradable Polymer Society—Third National Meeting, June 6–8, 1994, Boston, Massachusetts.     

机载产品日历寿命定寿方法研究进展及展望

联系我国飞机飞行现状,分析了机载产品日历寿命控制的必要性.根据文献记载,简要介绍了航空机载产品日历寿命定寿方法的发展历程,分析了目前机载产品日历寿命定寿方法研究的现状,归纳了3类主要的机载产品日历寿命传统定寿方法,并讨论了各类方法的优点与不足.针对传统定寿方法存在的问题,整理了近年来发展的机载产品日历寿命定寿方法的代表性成果,介绍了3种近年来才发展的机载产品日历寿命定延寿方法的具体过程.客观地综述了我国机载产品日历寿命研究存在的短板与弱项,以及日历寿命研究亟需发展的方向.为使机载产品日历寿命定寿方法研究跟上时代发展的步伐,更经济高效地服务在役飞机寿命控制,对未来机载产品日历寿命研究提出了展望.     

聚合硫酸铁絮凝剂中痕量镉测定的研究

研究了测定聚合硫酸铁絮凝剂中痕量镉的新方法。本法是利用离子选择性电极测定聚合硫酸铁絮凝剂中的镉。研究内容包括测定条件、干扰试验、干扰排除等。本法不需调整 p H值 ,设备简单 ,操作简便 ,测定快速。在测定条件下 ,本法的线性范围为 1 .0× 1 0 - 2 ～ 9.0× 1 0 - 7,回收率为 91 %～ 1 0 7% ,适宜的 p H值范围为 3- 6。本法用于了实际样品测定 ,结果满意。     

含泥沙水样总磷测定方法的研究

对含泥沙水样消解后不用滤膜过滤而改为直接定容于 5 0mL比色管中 ,经钼酸盐、抗坏血酸试剂显色后离心 ,取清液测定。经对比实验表明 ,该法灵敏度、精确度、准确度均满足环境监测技术规范要求 ,有效消除了泥沙对TP测定的影响     

增温快速测定BOD的动力学研究

应用ＢＯＤ反应动力学原理，从理论上建立了ＢＯＤ测定培养时间ｔ（ｄ）随培养温度Ｔ（℃）变化的数学模型，并导出通用增温培养时间，用通用增温培养时间２７℃下３天和３２℃下２天测得ＢＯＤ与标准法ＢＯＤ相一致，两者回归分析相关系数均大于０．９９９。