城市供水水质监管机制存在的问题及对策研究

为了保障城市供水水质安全卫生,分析多层面水质监管存在的问题和原因,提出具体对策：构建职责明确的企业自检、行业监测、行政监督制度,实现监管独立;打破信息孤岛,建立跨部门的水源水质监测防治委员会;实行水质产权化管理;建立纵向和横向信息沟通网络平台;建立饮用水断面水质指标评价体系和面向公众的水质指标综合评价体系;优化自备井和二次供水监管主体;建立社区用水协会,形成供水部门、公众和监管主体三位一体的信息渠道。     

深圳市主要饮用水水库水质的评价

采用标识指数法和污染指数法,评价和分析了深圳市13个主要饮用水库的水质状况。研究结果表明,深圳市饮用水库营养盐浓度较高,总氮和总磷超标的水库分别占92.3%和38.5%。按单因子评价法,石岩水库为Ⅴ类,深圳水库和罗田水库为Ⅳ类,梅林水库刚好达到Ⅱ类,其余水库为Ⅲ类。两种评价方法一致,而标识指数法不仅可以判断水质是否超标,而且能够确定水质具体类别,具有计算简单、分析结果直观等优点。     

不同土壤对垃圾渗滤液的吸附净化实验研究

文章以粘土和壤土为实验材料,研究两种不同土壤对渗滤液中COD、重金属含量的吸收净化效果。结果表明:相同高度的粘土比壤土吸附效果好,同一种土壤对pH、COD、重金属的去除效果随土层厚度的增加而增强。     

浅谈交通安全的管理方式

道路交通运输是由人与车组成的人-机系统,经人的操作而使车辆沿公路运动的过程,道路交通安全取决于人、车、路三个基本因素,协调好三者之间的关系是保证道路交通安全的前提,而协调人、车、路三个基本因素的关键因素是人.     

Evaluation of the infectivity, gene and antigenicity persistence of rotaviruses by free chlorine disinfection

The effects of free chlorine disinfection of tap water and wastewater effluents on the infectivity, gene integrity and surface antigens of rotaviruses were evaluated by a bench-scale chlorine disinfection experiments. Plaque assays, integrated cell culture-quantitative RT-PCR (ICC-RT-qPCR), RT-qPCR, and enzyme-linked immunosorbent assays (ELISA), respectively, were used to assess the influence of the disinfectant on virus infectivity as well as genetic and antigenic integrity of simian rotavirus SA11 as a surrogate for human rotaviruses. The ICC-RT-qPCR was able to detect rotaviruses survival from chlorine disinfection at chlorine dose up to 20 mg/L (60 min contact), which suggested a required chlorine dose of 5 folds (from 1 to 5 mg/L) higher than that indicated by the plaque assay to achieve 1.8 log₁₀ reductions in tap water with 60 min exposing. The VP7 gene was more resistant than the infectivity and existed at chlorine dose up to 20 mg/L (60 min contact), while the antigencity was undetectable with chlorine dose more than 5 mg/L (60 min contact). The water quality also impacted the inactivation efficiencies, and rotaviruses have a relatively higher resistant in secondary effluents than in the tap water under the same chlorine disinfection treatments. This study indicated that rotaviruses have a higher infectivity, gene and antigencity resistance to chlorine than that previously indicated by plaque assay only, which seemed to underestimate the resistance of rotaviruses to chlorine and the risk of rotaviruses in environments. Present results also suggested that re-evaluation of resistance of other waterborne viruses after disinfections by more sensitive infectivity detection method (such as ICC-RT-qPCR) may be necessary, to determine the adequate disinfectant doses required for the inactivation of waterborne viruses.     

In vitro fluorescence displacement investigation of thyroxine transport disruption by bisphenol A

Bisphenol A (BPA) is a chemical with high production volume and wide applications in many industries. Although BPA is known as an endocrine disruptor, its toxic mechanisms have not been fully characterized. Due to its structural similarity to thyroid hormones thyroxine (T4) and triiodothyronine (T3), one possible mechanism of BPA toxicity is disruption of hormone transport by competitive binding with the transport proteins. In this study, the binding interactions of BPA, T4, and T3 with three thyroid hormone transport proteins, human serum albumin (HSA), transthyretin (TTR), and thyroxine-binding globulin (TBG) were investigated by fluorescence measurement. Using two site-specific fluorescence probes dansylamide and dansyl-L-proline, the binding constants of BPA with HSA at drug site I and site II were determined as 2.90 104 and 3.14 104 L/mol, respectively. By monitoring the intrinsic fluorescence of tryptophan, a binding constant of 4.70 103 L/mol was obtained. Similarly, by employing 8-anilino-1-naphthalenesulfonic acid as fluorescence probe, the binding a nity of BPA with TTR and TBG was measured to be 3.10 105 and 5.90 105 L/mol, respectively. In general, BPA showed lower binding a nity with the proteins than T3 did, and even lower a nity than T4. Using these binding constants, the amount of BPA which would bind to the transport proteins in human plasma was estimated. These results suggest that the concentrations of BPA commonly found in human plasma are probably not high enough to interfere with T4 transport.     

信息化施工法在永蓝高速公路边坡工程中的应用

信息化施工是山区高速公路建设的关键技术之一,对路基、桥隧等的设计施工均发挥重要作用。本文以永蓝高速公路新铺子隧道出口高边坡工程为依托,对高速公路边坡工程信息化施工方法进行了系统的探讨。研究指出边坡工程信息化施工方法的主要内容是通过发掘施工中所揭露的地质信息,进行必要的位移和应力等方面的监测,以获得相应资料及数据进行边（...     

浅析污染源自动监测系统应用现状与发展思路

通过对污染自动监测系统应用现状和存在问题进行了分析,提出了污染源自动监测系统今后的发展思路。     

基于GIS的滇池流域景观格局优化

景观格局优化是景观生态学中的难点和热点问题。选择滇池流域为研究区域,在RS和GIS的支持下对2008年Landsat TM影像进行解译判读,获得景观类型图,运用最小耗费距离模型对区域景观格局进行优化。结合景观各组分生态系统服务功能价值和空间作用,构建了生态源地、生态廊道和生态节点等景观组分,以加强生态网络的空间连通性,提高景观格局稳定性,完善生态功能。源地具有较高的生态系统服务功能,需要维持和增大源斑块面积。所构建城市区域廊道、森林生态廊道、农业生产廊道应采取保持廊道规模,建立缓冲区,加强植被绿化,减少污染物的排放等措施以提高整个廊道的连通性。节点位于景观生态流和连通的重要位置上,需要加强控制。该研究对流域生态规划和土地利用优化布局有一定的参考价值。     

Understanding why consumers in China switch between wild,farmed, and synthetic bear bile products

An important rationale for legally farmed and synthetic wildlife products is that they reduce illegal, wild-sourced trade by supplying markets with sustainable alternatives. For this to work, more established illegal-product consumers must switch to legal alternatives than new legal-product consumers switch to illegal wild products. Despite the widespread debate on the magnitude and direction of switching, studies among actual consumers are lacking. We used an anonymous online survey of 1421 traditional Chinese medicine consumers in China to investigate switching among legal farmed, synthetic, and illegal wild bear bile. We examined the past consumption behavior, applied a discrete choice experiment framed within worsening hypothetical disease scenarios, and used latent class models to investigate groups with shared preferences. Bear bile consumers (86% respondents) were wealthier, more likely to have family who consumed bile, and less knowledgeable about bile treatments than nonconsumers. Consumer preferences were heterogenous, but most consumer preferences switched between bile types as disease worsened. We identified five distinct latent classes within our sample: law-abiding consumers (34% respondents), who prefer legal products and were unlikely to switch; two all-natural consumer groups (53%), who dislike synthetics but may switch between farmed and wild; and two nonconsumer groups (12%), who prefer not to buy bile. People with past experience of bile consumption had different preferences than those without. Willingness to switch to wild products was related to believing they were legal, although the likelihood of switching was mediated by preferences for cheaper products sold in legal, familiar places. We found that consumers of wild bile may switch to legal alternatives, given the availability of a range of products, whereas legal-product consumers may switch to illegal products if the barriers to doing so are small. Understanding preferences that promote or impede switching should be a key consideration when attempting to predict consumer behavior in complex wildlife markets.