The influencing factors of the WTP for the risk reduction of chemical industry accidents in China

To explore the factors that influence respondents’ willingness to pay (WTP) for the risk reduction of chemical industry accidents, a questionnaire survey combined with contingent valuation and psychometric paradigm methods were conducted in the city of Yancheng, Jiangsu Province, China. Both traditional socioeconomic variables and perceived characteristics of the hazards were considered in this study, and a Tobit model was used to find the factors influencing WTP under three risk reduction scenarios. The results showed that three demographic characteristics, age, gender, and income, significantly affected the WTP for chemical risk reduction. In addition, three extracted public risk perception factors, effect, knowledge, and trust, also strongly affected the WTP. The mean WTP value increased as the magnitude of the risk reduction increased. The number of factors influencing the WTP decreased as the reduction level improved, and only the effect factor had a significant influence on the WTP for a higher level (80%) of risk reduction. The cost for chemical safety management of Yancheng was calculated, and the optimized risk reduction level was determined. These findings can assist governments and policy makers to formulate suitable strategies for risk control, to reach target groups of people to develop effective communication, and to provide specific references for the best investment for the security of local residents.     

大气细颗粒物生殖毒性研究进展

大气污染已经成为中国最主要的污染问题.大气细颗粒物作为大气污染的主要成分,具有生殖毒性.本文总结了大气细颗粒物生殖毒性的流行病调查及其动物实验结果,并主要从氧化应激、DNA损伤、炎症反应和血睾屏障的完整性破坏等方面,归纳了近年来大气细颗粒物生殖毒性作用机制的研究成果,对现有研究中存在的问题进行了探讨,这有助于深入推进大气细颗粒物的生殖毒性研究.     

Using loose nanofiltration membrane for lake water treatment: A pilot study

• A pilot study was conducted for drinking water treatment using loose NF membranes. • The membranes had very high rejection of NOM and medium rejection of Ca²⁺/Mg²⁺. • Organic fouling was dominant and contribution of inorganic fouling was substantial. • Both organic and inorganic fouling had spatial non-uniformity on membrane surface. • Applying EDTA at basic conditions was effective in removing membrane fouling. Nanofiltration (NF) using loose membranes has a high application potential for advanced treatment of drinking water by selectively removing contaminants from the water, while membrane fouling remains one of the biggest problems of the process. This paper reported a seven-month pilot study of using a loose NF membrane to treat a sand filtration effluent which had a relatively high turbidity (~0.4 NTU) and high concentrations of organic matter (up to 5 mg/L as TOC), hardness and sulfate. Results showed that the membrane demonstrated a high rejection of TOC (by>90%) and a moderately high rejection of two pesticides (54%–82%) while a moderate rejection of both calcium and magnesium (~45%) and a low rejection of total dissolved solids (~27%). The membrane elements suffered from severe membrane fouling, with the membrane permeance decreased by 70% after 85 days operation. The membrane fouling was dominated by organic fouling, while biological fouling was moderate. Inorganic fouling was mainly caused by deposition of aluminum-bearing substances. Though inorganic foulants were minor contents on membrane, their contribution to overall membrane fouling was substantial. Membrane fouling was not uniform on membrane. While contents of organic and inorganic foulants were the highest at the inlet and outlet region, respectively, the severity of membrane fouling increased from the inlet to the outlet region of membrane element with a difference higher than 30%. While alkaline cleaning was not effective in removing the membrane foulants, the use of ethylenediamine tetraacetate (EDTA) at alkaline conditions could effectively restore the membrane permeance.     

Scalar mixing in an urban canyon

The scalar dynamics within a unit-aspect-ratio street canyon are studied using large-eddy simulation. The key processes of ventilation and mixing are analysed with the canyon-averaged concentration, mean tracer age and variance. The results are sensitive to the source location and can be classified according to the streamline geometry. The canyon-averaged concentrations for the corner vortices, vortex sea and central vortex do not converge to the same value at large times, though the mean decay rates do. The variance measured with respect to the canyon average shows two distinct decay regimes: the early regime reflects large-scale straining and enhanced diffusion across streamlines, while the late regime is associated with escape from the canyon, i.e., ventilation. Analytical predictions for the variance-decay or mixing time scales are verified for the early regime. It is argued that the presence of an open boundary at the roof level suppresses rapid mixing of the scalar field and is responsible for differences with respect to scalar dynamics within closed domains.

     

新型杀菌剂双季铵盐BQAS性能试验研究

新型杀菌剂双季铵盐以其低毒、性能优良而受到广泛的关注。以自制的N,N-二甲基十二烷基叔胺和1,4-二溴丁烷为原料合成产物双季铵盐(BQAS)。对双季铵盐BQAS的杀菌性能及缓蚀性能研究表明,双季铵盐对SRB和TGB的杀灭能力均优于1227,双季铵盐在有氧中性水介质中表现出一定的缓蚀性能,并具有较强的杀菌能力,是一种吸附成膜型缓蚀剂。     

应用特殊精馏技术从制药废液中回收四氢呋喃

研究了萃取精馏技术和反应萃取精馏技术在回收四氢呋喃（ＴＨＦ）中的应用,选择了萃取剂和反应萃取剂,设计了工艺流程,优化了操作条件,试验结果表明,采用以上技术从制药废液中回收的ＴＨＦ,纯度可达到９９．４％。     

金属表面处理清洗废水治理

通过对深圳金德博通讯设备有限公司金属表面处理清洗废水的治理，总结出一种可行的金属表面处理废水的处理方法。     

井下作业温度对事故影响关系的灰色关联分析

笔者基于灰色系统理论 ,结合煤矿井下运输生产实际 ,建立了以死亡人数为参考数列、以不同作业温度为比较数列的灰色关联分析体系。通过对构造的不同数据列的无量纲化处理、求取差序列 ,计算灰色关联系数等 ,得到了不同作业温度对伤亡事故影响的灰色关联度 ,并据此分析结果而找出了井下作业温度对死亡事故的影响关系 ,为预防事故发生、减少伤亡损失及改善作业环境提供了有用的依据     

马铃薯糖苷生物碱的生物学作用及开发利用

本文根据作者近年的研究成果及国外研究动态，简要介绍了马铃薯糖苷生物碱的种类，结构，含量及在植株中的分布；重点论述了糖苷生物碱的毒性，毒理及对块茎食用、饲用和加工品质的影响，糖苷生物碱与马铃薯植株自身的抗病，抗虫性及其抗病虫育种的关系，以及糖苷生物碱在医药学中的应用价值，为马铃薯的综合开发利用指出了新途径。     

延津县沙荒地的开发与治理

本文客观地分析了延津县沙区的自然资源状况，开发潜力及存在的问题，提出了开发治理的方向和关键技术，为我国同类地区风沙化土地的开发治理提供了经验。