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881.
The aim of this study was to investigate the detailed metal speciation/fractionations of a Cu contaminated soil before and after electrokinetic remediation as well as their relationships with the soil microbial and enzyme activities. Significant changes in the exchangeable and adsorbed-Cu fractionations occurred after electrokinetic treatment, while labile soil Cu in the solution had a tendency to decrease from the anode to the cathode, and the soil free Cu2+ ions were mainly accumulated in the sections close to the cathode. The results of regression analyses revealed that both the soil Cu speciation in solution phase and the Cu fractionations in solid phase could play important roles in the changes of the soil microbial and enzyme activities. Our findings suggest that the bioavailability of soil heavy metals and their ecotoxicological effects on the soil biota before and after electroremediation can be better understood in terms of their chemical speciation and fractionations.  相似文献   
882.
This paper proposes a welfare criterion that balances the need for development and the concern for the least advantaged generations, and explores its implications. This criterion, called the mixed Bentham–Rawls criterion, moderates the effect of discounting, yet permits some degree of intertemporal trade-off. It is a weighted average of two terms: (a) the sum of discounted utilities and (b) the utility level of the least advantaged generation. We derive necessary conditions to characterize growth paths that satisfy our criterion, and show that in some models with familiar dynamic specifications, an optimal path exists and displays appealing characteristics.  相似文献   
883.
Environmental Science and Pollution Research - Antimony (Sb) is a toxic pollutant, but data for Sb toxicity to springtails in soil are limited, and the effects of Sb speciation, soil physiochemical...  相似文献   
884.

Transport sector contributed numerous carbon emissions in China. It is important to promote low-carbon bicycle-sharing using in China. This paper aims to analyze the influencing factors of the satisfaction and engagement of bicycle-sharing in China. An extended model of customer satisfaction is established, which considers both customer satisfaction theory and customer engagement theory. We explore the different effect of convenience, health, safety, and facility on satisfaction of bicycle-sharing using. We also explore the role of satisfaction on three different dimensions of engagement: enthusiasm, participation, and social interaction. Multi-group structure equation model is employed to explore the different roles of gender on the determinants of satisfaction and engagement of bicycle-sharing using. The findings reveal that facilities had the larger effect on satisfaction of bicycle-sharing using than safety and health for male. Safety had the largest influence on satisfaction of bicycle-sharing using for female, followed by facility, convenience, and health.

  相似文献   
885.
886.
Journal of Material Cycles and Waste Management - The reinforcement and compatibilization efficiency of shield powder (modified steel slag powder) for partial replacement of active calcium...  相似文献   
887.
Environmental Science and Pollution Research - Nostoc flagelliforme is a remarkable drought-resistant terrestrial cyanobacterium whose exopolysaccharides (EPS) have been found to exert important...  相似文献   
888.
Environmental Science and Pollution Research - The purpose of this research is to measure the combing impact of corporate social responsibility on company performance and to conduct a comparative...  相似文献   
889.
基于FDS的高校宿舍火灾数值模拟   总被引:1,自引:1,他引:0  
采用美国国家标准和美国技术研究院(NIST)开发的FDS软件,建立了高校宿舍火灾模型,对宿舍火灾进行全尺寸模拟,通过模拟试验给出了火灾发生过程中烟气运动、温度变化和氧气浓度变化的规律.  相似文献   
890.
为解决零价铁(ZVI)作为渗透反应格栅(PRB)反应介质处理六价铬〔Cr(Ⅵ)〕时产生钝化导致处理效率低的问题,提出了在反应介质上施加低直流电压,产生微电流去钝化的措施。通过PRB柱流动模拟试验,以粒径为0.15~0.35 mm的工业铁粉为反应介质,施加不同低电压,分析ZVI去除Cr(Ⅵ)的效果。结果表明:当Cr(Ⅵ)去除率达到60%时,施加1、3、7 V电压的试验组对应的出水体积分别是对照组的1.42、1.88和2.75倍;微电流可以在一定程度上解决ZVI的钝化问题,提高ZVI的利用效率,施加电压增大,ZVI的利用效率逐渐增高;施加电压产生的微电流对Cr(Ⅲ)沉淀影响不大,会对Fe(Ⅱ)或Fe(Ⅲ)的沉淀物产生影响。  相似文献   
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