全氟化合物污染现状及风险评估的研究进展

全氟化合物(polyfluorinated compounds,PFCs)是近年来受到广泛关注的一类新型持久性有机污染物。PFCs因具有优良的化学稳定性、耐热性以及高表面活性,而被广泛应用于生活消费和工业生产等领域。PFCs具有难降解、生物富集和长距离迁移等特点,已在大气、土壤和水体等环境介质及生物体中检出。在生态环境中,PFCs能够通过食物链不断传递放大,其具有的多种毒性效应已对生态系统和人类造成了一定的威胁。本文主要综述了PFCs在各类环境介质的污染现状、生物的毒性效应、人类摄入健康风险评估以及PFCs的降解研究,以期为未来PFCs的研究提供参考。     

水稻中硅元素的分布及存在状态

利用UV-Vis分光光度计、X线分析显微镜及扫描电子显微镜(Scanning electron microscope,SEM)对水稻不同器官中硅元素的含量、分布及存在状态进行观察和分析,研究水稻中硅酸的化学性质,为水稻硅元素的综合利用提供科学依据.结果表明:水稻以可溶性原硅酸的形式吸收土壤中的硅酸,同样以可溶性原硅酸的形式输送到各器官中.不同的生长期,水稻导管液内的可溶性原硅酸的含量不同,成熟期最高可达到912 mg/L(以SiO2表示).通过比较导管汁液和土壤溶液的硅酸浓度可知,水稻选择性地吸收和浓缩硅酸,最高浓缩率可达85倍.X线分析显微镜观察发现,硅酸普遍存在于水稻各器官中,越是坚硬的部位硅酸分布得越多.SEM图像表明,沉积在水稻各器官中的硅胶体具有一定的形状且不溶于强酸.对水稻干燥组分中硅酸含量的分析结果表明,稻壳中硅酸含量最高,达到13.3%,是生产硅单质及碳化硅材料的最有效的资源之一.     

垃圾填埋场渗滤液处理研究进展

文章综述了垃圾填埋场渗滤液的研究情况,包括渗滤液的产生、危害、水质和水量、控制和处理,并提出了今后的研究方向,供从事此项研究的工作人员参考     

刍议医院资产管理的现状及其对策

医院的固定资产和流动资产是医院赖以生存和发展的基础,是一项非经营性国有资产．目前公立医院固定资产、流动资产管理现状不容乐观,针对这种状况,首先分析问题形成的原因,然后提出管理的措施或建议,从而使资产管理工作规范化、制度化、科学化,使有限的卫生资源发挥出最大的社会效益和经济效益．参3．     

Trading rules and the environment: Does equal treatment lead to a cleaner world?

In this paper, we consider a three-stage game in the context of a competing exporters model to compare and contrast the effects of discriminatory and uniform (Most Favored Nation, MFN) tariffs on countries’ choice over environmental standards for varying degrees of pollution spillovers. Because of the presence of punishment effects and stronger own and cross-tariff effects, we find that discrimination yields higher standards than MFN (and free trade) independently of the extent of pollution spillovers. When pollution is local and incentives to free ride on other countries’ abatement efforts are weak, we show, however, that welfare is larger under MFN than under discrimination. In a dynamic setting, we consider the impact of symmetric and asymmetric treatments on the sustainability of an international environmental agreement (IEA) and obtain that multilateral cooperation is easier to sustain under discrimination than under MFN (or free trade).     

Optimal Allocation of Resources among Threatened Species: a Project Prioritization Protocol

Abstract: Conservation funds are grossly inadequate to address the plight of threatened species. Government and conservation organizations faced with the task of conserving threatened species desperately need simple strategies for allocating limited resources. The academic literature dedicated to systematic priority setting usually recommends ranking species on several criteria, including level of endangerment and metrics of species value such as evolutionary distinctiveness, ecological importance, and social significance. These approaches ignore 2 crucial factors: the cost of management and the likelihood that the management will succeed. These oversights will result in misallocation of scarce conservation resources and possibly unnecessary losses. We devised a project prioritization protocol (PPP) to optimize resource allocation among New Zealand's threatened‐species projects, where costs, benefits (including species values), and the likelihood of management success were considered simultaneously. We compared the number of species managed and the expected benefits gained with 5 prioritization criteria: PPP with weightings based on species value; PPP with species weighted equally; management costs; species value; and threat status. We found that the rational use of cost and success information substantially increased the number of species managed, and prioritizing management projects according to species value or threat status in isolation was inefficient and resulted in fewer species managed. In addition, we found a clear trade‐off between funding management of a greater number of the most cost‐efficient and least risky projects and funding fewer projects to manage the species of higher value. Specifically, 11 of 32 species projects could be funded if projects were weighted by species value compared with 16 projects if projects were not weighted. This highlights the value of a transparent decision‐making process, which enables a careful consideration of trade‐offs. The use of PPP can substantially improve conservation outcomes for threatened species by increasing efficiency and ensuring transparency of management decisions.     

柴油机排气微粒组分及尺寸分布研究现状分析

对柴油机微粒的研究是控制微粒排放的前提,也是满足未来排放法规的需要。从柴油机微粒形成的机理及其危害出发,介绍了柴油机微粒的检测方法,对柴油机微粒的组成及尺寸分布研究现状进行分析。对柴油机微粒的控制和净化技术的研究有一定的指导作用。     

企业文化与企业安全文化建设水平互动效应研究

为提高企业安全文化建设水平,基于人类协同国际环形和企业安全文化建设水平评价指标设计调查问卷,以赛轮金宇股份有限公司为研究对象,对其企业文化和企业安全文化建设水平进行相关性分析和多元逐步回归分析,探索二者的互动效应,从企业文化角度发掘安全文化建设重点。结果表明,自我实现文化、亲和文化、传统文化、成就文化与企业安全文化建设水平高度正相关,逃避文化则呈现高度负相关,其相关系数（绝对值）均在0.9以上;同时,多元逐步回归分析中,以上5个文化规则均进入回归方程,其标准化回归系数β分别为:0.395、0.182、0.169、0.129、-0.145。因此,这5种文化规则对企业安全文化建设水平具有很高的预测力,是企业安全文化建设的重点所在。     

结合态雌激素的检测方法及污染现状

结合态雌激素是天然雌激素物质的一种重要赋存形态,在环境中可水解为自由态,产生内分泌干扰效应,因此具有潜在的环境风险,并且会影响天然雌激素污染调查和毒性评估的准确性.本文详细探讨了结合态雌激素特定的化学结构对其检测、转化及环境风险等方面的影响,对比分析了目前常用的几类检测方法的优缺点,并初步总结了其在污水处理设施和环境水体中的污染浓度及归趋,以期为我国开展相关研究工作提供参考.     

Climate and international trade policies when emissions affect production possibilities

In this paper, we develop a model of international trade and climate change in which emission discharges arising from production have a feedback effect on national production sectors by impacting upon effective factor endowments. With this context, the objectives are, first, to provide a general characterization of Pareto-efficient climate and trade policies and, second, to examine the possibility – starting from non-Pareto-efficient equilibria – for Pareto-improving environmental policies. We provide conditions under which several particular reforms of carbon taxes are welfare improving.