聚硅氯化铝混凝剂的形态及带电特性研究

以ＡｌＣｌ３·６Ｈ２Ｏ、ＮａＯＨ、盐酸和水玻璃为原料制备了不同碱化度（Ｂ）及不同Ｓｉ／Ａｌ摩尔比的系列聚硅氯化铝混凝剂（ＰＡＳＣ）,采用Ａｌ－Ｆｅｒｒｏｎ逐时络合比色法和微电泳技术研究了ＰＡＳＣ中铝的水解产物形态分布及铝的水解沉淀物的带电特性,考察了Ｂ及Ｓｉ／Ａｌ摩尔比对ＰＡＳＣ中铝水解产物形态分布及带电特性的影响情况,并与聚合氯化铝（ＰＡＣ）进行了比较,实验结果表明,Ｂ对ＰＡＳＣ的形态分布有较大     

Municipalities’ ambitions and practices: At risk of hypocritical sustainability transitions?

In contemporary planning discourse and practice, different planning ideas co-exists. How this affects the transition towards a sustainable development is an important question for both research and practice. The aim of this study is to explore potential conflicts between planning goals caught between growth-led planning and sustainability commitments in a case study of Fredericia, Denmark. The paper discusses the underlying, framing and controlling conditions for transition dynamics. The analysis builds largely on the formulated policies, strategies or national goal achievements towards sustainable futures. These are put in the context of planning and political practices, which are interpreted from a sustainability rationale. Here this study introduces hypocrisy as a theoretical-analytical perspective to dispute actual sustainability practices to respond to continuous ambivalent planning measures. The author concludes that disregarding the inherently different internal logics of growths and sustainability leads to planning paradoxes and impedes sustainable transitions pursued.     

National infrastructure,small towns and sustainable mobility – experiences from policy and strategy in two Swedish municipalities

This study explores the implications of improved access to national rail and road infrastructure for urban planning and land use in two small Swedish towns. The promotion of sustainable mobility is considered a strategic objective at the municipal level, yet the study questions the extent to which national investments, and increased access to regional labour markets, support local efforts to increase sustainable mobility. The results indicate that municipalities struggle to adopt coherent approaches to increasing sustainable mobility and continue to develop physical plans that induce use of motor vehicles, a trend reinforced by national investments in road infrastructure in peri-urban areas.     

Financial inadequacy and the disadvantageous changes in time perspective and goal-striving strategies throughout life

As inequality in wealth and income continues to grow, it is important to consider the implications of financial disparities for worker motivation and behavior. While workers with socioeconomic disadvantages have a decreased chance of career success and upward social mobility, the potential mechanisms linking financial status to work motivation outcomes are not fully known. Drawing on theory on resource scarcity, we address this issue and propose that financial inadequacy shapes the extent to which workers consider and plan for the future, with consequences for goal-striving strategies throughout adulthood. Latent change analyses of data from a heterogeneous sample of 4,446 working adults largely supported the hypotheses. Results showed that a high level of financial inadequacy predicted increases in short-term time horizon and decreases in future-oriented planning, which then predicted disadvantageous changes in goal-striving strategies over an 18-year period. Short-term time horizon also predicted subsequent increases in financial inadequacy. By highlighting the motivational challenges associated with inadequate finances that accompany low-wage employment, our study offers evidence for the motivational mechanisms that may reinforce economic inequality and social mobility in the workforce.     

基于人口视角的公共服务均等化改革

公共服务的利益分享和成本分担,最终都会落实到每一个人的身上,"人"是其中的一个重要影响因素.我国不同社会成员享有的公共服务水平存在着很大的不同,而且各自所承担的公共服务提供成本也有着较大的差距.本文立足于"人"这一基点,从三个方面剖析了我国公共服务非均等格局形成的原因:①长期存在的对"人"身份进行区分的传统及其在我国社会经济制度中的体现是我国公共服务非均等格局形成的根源;②人口流动性的缺乏为我国公共服务非均等格局的形成提供了某种便利;③巨大的人口规模以及农村人口占多数的人口结构等也加剧了我国公共服务非均等格局的程度.从"人"的角度看,我国推进公共服务均等化改革的基本思路是:彻底消除身份传统在公共服务体制中的影响,建立起无差别的公共服务供给制度和公平的公共服务成本分担机制;努力提高人口的流动性,并使社会经济改革与不新提高的人口流动性相适应;通过大力发展中小城镇等方式来适当调整人口结构.     

EDTA-enhanced phytoremediation of lead contaminated soil by Bidens maximowicziana

Phytoremediation is a potential cleanup technology for the removal of heavy metals from contaminated soils.Bidens maximowicziana is a new Pb hyperaccumulator,which not only has remarkable tolerance to Pb but also extraordinary accumulation capacity for Pb.The maximum Pb concentration was 1509.3 mg/kg in roots and 2164.7 mg/kg in overground tissues.The Pb distribution order in the B. maximowicziana was:leaf>stem>root.The effect of amendments on phytoremediation was also studied.The mobility of soil Pb and the Pb concentrations in plants were both increased by EDTA application.Compared with CK(control check),EDTA application promoted translocation of Pb to overground parts of the plant.The Pb concentrations in overground parts of plants was increased from 24.23-680.56 mg/kg to 29.07-1905.57 mg/kg.This research demonstrated that B.maximowicziana appeared to be suitable for phytoremediation of Pb contaminated soil,especially,combination with EDTA.     

Modelling the closure-related geochemical evolution of groundwater at a former uranium mine

A newly developed reactive transport model was used to evaluate the potential effects of mine closure on the geochemical evolution in the aquifer downgradient from a mine site. The simulations were conducted for the K?nigstein uranium mine located in Saxony, Germany. During decades of operation, uranium at the former mine site had been extracted by in situ acid leaching of the ore underground, while the mine was maintained in a dewatered condition. One option for decommissioning is to allow the groundwater level to rise to its natural level, flooding the mine workings. As a result, pore water containing high concentrations of dissolved metals, radionuclides, and sulfate may be released. Additional contamination may arise due to the dissolution of minerals contained in the aquifer downgradient of the mine. On the other hand, dissolved metals may be attenuated by reactions within the aquifer. The geochemical processes and interactions involved are highly non-linear and their impact on the quality of the groundwater and surface water downstream of the mine is not always intuitive. The multicomponent reactive transport model MIN3P, which can describe mineral dissolution-precipitation reactions, aqueous complexation, and oxidation-reduction reactions, is shown to be a powerful tool for investigating these processes. The predictive capabilities of the model are, however, limited by the availability of key geochemical parameters such as the presence and quantities of primary and secondary mineral phases. Under these conditions, the model can provide valuable insight by means of sensitivity analyses.     

重金属化学活性评估方法准确性质疑--以煤矸石样品为例

重金属元素化学活性的大小是决定它们环境行为最主要的因素之一,我们曾分别用总量法,实验模拟法,环境地球化学法和化学形态分析法对煤矸石样品所含的重金属元素进行过环境影响分析,试图了解自然风化条件下这些有害元素潜在的生态环境效应,结果发现重金属元素的化学活性除了与它们在样品中含量的高低,赋存状态和化学形态等因素有关外,更主要地是取决于样品基质的组成和结构,由于大量有机质的络合和风化过程中生成的铁的胶体的吸附,从煤矸石释放出的重金属元素的化学活性受到明显限制,它们对环境的污染可能仅限于煤矸石堆周围有限的范围。     

异菌脲在土壤中的降解和移动性研究

为明确异菌脲在土壤中的迁移和归趋特征,采用室内模拟方法研究异菌脲在4种不同类型土壤中的降解和移动性以及不同因素对异菌脲降解的影响。结果表明,异菌脲在不同类型土壤中的降解顺序为东北黑土青海草甸土南京黄棕壤江西红壤,降解半衰期分别为7.2、8.6、12.7和16.9 d,异菌脲在4种土壤中均属于易降解农药。土壤湿度越大,异菌脲降解越快,渍水条件下降解速率加快,说明厌氧微生物对异菌脲降解起重要作用。微生物和有机质对异菌脲在土壤降解过程中有一定的促进作用,在微生物、有机质存在的条件下异菌脲降解速率分别提高1.8倍、3.7倍。薄层层析试验表明,异菌脲在南京黄棕壤、东北黑土、江西红壤和青海草甸土的比移值(R_f)分别为0.19、0.17、0.29和0.17,异菌脲在4种土壤中均属于不易移动,土柱淋溶试验结果表明,异菌脲在4种土壤中均属于难淋溶,不易通过淋溶作用造成地下水污染。