Characterization of eco-cement paste produced from waste sludges

In this study, marble sludge, sewage sludge, drinking water treatment plant sludge, and basic oxygen furnace sludge were used as replacements for limestone, sand, clay, and iron slag, respectively, as the raw materials for the production of cement in order to produce eco-cement. It was found that it is feasible to use marble sludge to replace up to 50% of the limestone and also that other materials can serve as total replacements for the raw materials typically used in the production of cement. The major components of Portland cement were all found in eco-cement clinkers. The eco-cement was confirmed to produce calcium hydroxide and calcium silicate hydrates during the hydration process, increasing densification with the curing age. The compressive strength (S_c) and microstructural evaluations conducted at 28 d revealed the usefulness of eco-cement. It was observed that the S_c data correlated linearly with the pore volume (P) data at 28 d. The proposed model equation could be represented as S_c = 178-461P (correlation coefficient, R² = 0.96). Two parameters, the large capillary pore volume and the medium capillary pore volume, were evaluated using multiple regression analysis.     

机场安检人员工作压力源及影响因素研究

探讨国内机场安检人员的工作压力源,为开展航空安全心理援助提供有效的依据。通过运用叙述统计分析、主成分分析、t检定、因子分析、多变量分析等方法对机场安检人员工作压力进行分析。对机场安检人员调查问卷进行数据统计的基础上,将采集的有效数据导入SPSS14.0进行检验,Bartlett球形检验结果(2χ=269.713,P=0.000<0.01,KMO值=0.533>0.5),表明采集数据各个变量之间是独立的,适用于进行主成分分析。主成分分析结果表明人际关系因子、工作负荷因子和设备及法令法规因子为机场安检人员的主要压力源。工资收入和工作年限对压力源有显著的影响。工资越低的人感觉工作负荷越大。工作年限10年以上的人在工作负荷和设备与法令规定因子感受较强烈。调查问卷设计合理,涵盖了较为全面的职业压力信息,所获压力因子具有一定的客观性和代表性。     

A composite receptor and dispersion model approach for estimation of effective emission factors for vehicles

It is difficult to estimate vehicular emission factors at traffic junctions for use in dispersion modelling studies. Firstly, because the vehicles are in various modes of operation and secondly, it is difficult to delineate the effects of other contributing sources, mainly the effects of road dust and deposited constituents, which are very prominent at traffic junctions in India. Factor analysis-multiple regression (FA-MR), a receptor modelling technique has been used in this study for apportioning the contributing sources. The measurement data consist of one year's temporal variation of suspended particulate matter (SPM), analysed for its trace metal constituents, and two gaseous components NO₂ and SO₂ at two traffic junctions in Mumbai (India). FA-MR apportioned 40% of the observed SPM to road dust and 15% to vehicular sources. Of the total Pb observed in the SPM, FA-MR apportioned 60% to vehicular sources and 20% to road dust. The field-observed vehicular counts, meteorological parameters and road geometry were used in California line source dispersion model to estimate the effective vehicular emission factor for Pb at one traffic junction. This derived emission factor was used to predict the Pb concentration at second (independent observation) traffic junction. The result was found to be more satisfactory than using default emission factors obtained from literature. Similarly, effective vehicular emission factor for NO₂ was also evaluated for one site and tested for predicting concentrations at the other site.     

ICP-MS/MS直接测定海水中12种痕量金属元素

建立一种采用电感耦合等离子体串联质谱 (ICP-MS/MS) 直接测定海水中12种元素的分析方法。采用标准加入法及配置超高基体进样系统实现基体匹配,应用ICP-MS/MS的多种分析模式测定海水中钒（V）、铬（Cr）、锰（Mn）、钴（Co）、镍（Ni）、铜（Cu）、锌（Zn）、砷（As）、钼（Mo）、镉（Cd）、铊（Tl）、铅（Pb）12种痕量元素。用该方法测定海水标准参考物质,结果准确。测定实际海水样品,加标回收率为85.0%~108%,相对标准偏差为1.5%~5.4%。12种元素的方法检出限为0.003~0.085 μg/L,定量下限为0.012~0.340 μg/L。该方法运行成本低,操作便捷,可作为实验室海水元素分析的常规检测方法。     

不同降水年型环境因子对水质的影响

通过检测2019年和2021年7月—9月颍河源头流域水质,采用多元逐步线性回归分析和冗余分析检验环境因子与水质之间的关系.结果表明:2019年(平水年)流域pH值和EC值较高,而2021年(丰水年)N和P含量较高,这说明强降水可能会导致水体富营养化,而正常降水则更可能出现无机污染.平水年总体水质变化与农业用地面积占比和平均海拔高度相关,两者分别占总解释率的31.1％和18.6％.丰水年总体水质变化的主要影响因子为农业用地面积占比和斑块密度,分别占总解释率的26.1％和15.9％.环境因子在平水年和丰水年对总体水质变化的影响分别占总解释率的74.2％和 69.3％.     

Management Objective Importance in Fisheries: An Evaluation Using the Analytic Hierarchy Process (AHP)

In determining the importance of criteria in the management of fisheries, two key issues stand out—the definition of a succinct set of criteria and the determination of which interest groups play a defining role in the management development process. This is indeed the case for all natural resource management problems, and many other environmental problems as well. The analytic hierarchy process (AHP) provides an effective framework for such an analysis. The AHP is generally used to evaluate importance amongst criteria based on the concept of paired comparison. This paper considers the development of a representative criteria hierarchy, and uses data obtained from a pairwise comparison survey based on the UK fisheries of the English Channel to investigate priorities that exist among different interest groups in the fisheries. The implementation of the AHP in this application provides a useful tool for analysis of criteria amongst groups involved in the management process with diverse interests.     

The Environmental “Risky” Region: Identifying Land Degradation Processes Through Integration of Socio-Economic and Ecological Indicators in a Multivariate Regionalization Model

The economic policy needs to pay increasingly more attention to the environmental issues, which requires the development of methodologies able to incorporate environmental, as well as macroeconomic, goals in the design of public policies. Starting from this observation, this article proposes a methodology based upon a Simonian satisficing logic made operational with the help of goal programming (GP) models, to address the joint design of macroeconomic and environmental policies. The methodology is applied to the Spanish economy, where a joint policy is elicited, taking into consideration macroeconomic goals (economic growth, inflation, unemployment, public deficit) and environmental goals (CO₂, NO _x and SO _x emissions) within the context of a computable general equilibrium model. The results show how the government can “fine-tune” its policy according to different criteria using GP models. The resulting policies aggregate the environmental and the economic goals in different ways: maximum aggregate performance, maximum balance and a lexicographic hierarchy of the goals.     

A two-stage inexact joint-probabilistic programming method for air quality management under uncertainty

A two-stage inexact joint-probabilistic programming (TIJP) method is developed for planning a regional air quality management system with multiple pollutants and multiple sources. The TIJP method incorporates the techniques of two-stage stochastic programming, joint-probabilistic constraint programming and interval mathematical programming, where uncertainties expressed as probability distributions and interval values can be addressed. Moreover, it can not only examine the risk of violating joint-probability constraints, but also account for economic penalties as corrective measures against any infeasibility. The developed TIJP method is applied to a case study of a regional air pollution control problem, where the air quality index (AQI) is introduced for evaluation of the integrated air quality management system associated with multiple pollutants. The joint-probability exists in the environmental constraints for AQI, such that individual probabilistic constraints for each pollutant can be efficiently incorporated within the TIJP model. The results indicate that useful solutions for air quality management practices have been generated; they can help decision makers to identify desired pollution abatement strategies with minimized system cost and maximized environmental efficiency.     

探析资源环境承载力约束下的“多规合一”思路

在我国进一步加强城市治理、大力开展环境与资源保护工作中,提出相关部门需要通力合作,实现"多规合一"的要求。而在"多规合一"中,资源环境承载力及其约束发挥了重要的作用。本文立足于此背景,在阐明资源环境承载力与"多规合一"基本内涵的基础上,结合相关研究资料,重点围绕资源环境承载力约束下的"多规合一"思路进行简要分析研究。