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71.
Kamal A. Rashid C.D. Ercegovich Ralph O. Mumma 《Journal of environmental science and health. Part. B》2013,48(1):95-110
Abstract The mutagenic activity of chlordimeform and two of its breakdown products, 4‐chloro‐o‐toludine and 4‐chloro‐N‐formyl‐o‐toluidine were determined with five histidine dependent strains of Salmonella typhimurium (TA1535, TA1537, TA1538, TA98, TA100) and five tryptophan dependent strains of E. coli WP2. (WP2, WP2uvrA, WP67, CM611, CM571) with and without rat liver microsomal enzymes. 4‐chloro‐o‐toluidine increased the number of the reversions of the S. typhimurium strain TA1535 more than two fold over spontaneous at the concentration of 400 μg/plate. The results of the DNA repair tests in the Salmonella TA1538/TA1978 and E. coli multirepair deficient systems showed that both breakdown products were active in inducing damage not repaired in at least one repair deficient strain while chlordimeform itself was inactive. 相似文献
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《International Journal of Sustainable Engineering》2013,6(4):352-358
Energy usage and consumption play important and strategic roles in modern manufacturing, inventory and logistics systems. The literature on inventory models for closed-loop supply chains reveals that, for no clear reasons, energy costs were ignored along with transportation and disposal costs. This paper introduces a closed-loop supply chain model that considers the economic value and energy content of products. It also offers a novel framework for studying lot-sizing policies of production processes in that context. Thus, a mathematical model for a closed-loop supply chain system with energy, transportation and disposal costs is developed. Numerical examples are provided with their results discussed. The developed model was also compared to that of Richter (1996) to stress the importance of accounting for the three noted costs. The numerical results emphasise that accounting for energy, transportation and disposal costs in supply chain modelling increases the sustainability of a production-inventory system due to the strong interdependence of the three costs on one hand, and their relationship to the environment on the other hand. 相似文献
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The effects of elevated concentrations of atmospheric tropospheric ozone (O3) on DNA damage in five trembling aspen (Populus tremuloides Michx.) clones growing in a free-air enrichment experiment in the presence and absence of elevated concentrations of carbon dioxide (CO2) were examined. Growing season mean hourly O3 concentrations were 36.3 and 47.3 ppb for ambient and elevated O3 plots, respectively. The 4th highest daily maximum 8-h ambient and elevated O3 concentrations were 79 and 89 ppb, respectively. Elevated CO2 averaged 524 ppm (+150 ppm) over the growing season. Exposure to O3 and CO2 in combination with O3 increased DNA damage levels above background as measured by the comet assay. Ozone-tolerant clones 271 and 8L showed the highest levels of DNA damage under elevated O3 compared with ambient air; whereas less tolerant clone 216 and sensitive clones 42E and 259 had comparably lower levels of DNA damage with no significant differences between elevated O3 and ambient air. Clone 8L was demonstrated to have the highest level of excision DNA repair. In addition, clone 271 had the highest level of oxidative damage as measured by lipid peroxidation. The results suggest that variation in cellular responses to DNA damage between aspen clones may contribute to O3 tolerance or sensitivity. 相似文献
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目的对比、评价服役于海洋大气环境中直升机结构钢防护体系的防护性能。方法通过模拟海洋大气环境加速试验方法,研究直升机结构钢防护体系在实际服役过程中出现的损伤。结果涂层A微观结构较为疏松,加速试验中涂层基体产生鼓泡,并发生腐蚀。电化学阻抗谱(EIS)方法测得低频区的阻抗模值相对较低,说明涂层防护性能较差,与宏观试验结果一致。结论在模拟海洋大气环境的加速试验中,涂层表面的微小缺陷(如疏松结构中的微小孔洞)会成为腐蚀溶液进入的快速通道,进而降低涂层的防护性能。利用电化学阻抗谱(EIS)方法可有效表征有机涂层涂覆下的金属腐蚀行为,并评估涂层的防护性能。 相似文献
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目的研究高原高寒环境对直升机航电系统试验的影响、应对以及直升机环境适应性评价方法。方法通过分析高原高寒环境对直升机航电系统的影响因素,建立评价指标体系,运用模糊综合评价方法,得出直升机航电系统在高原高寒环境下适应性评价值。结果直升机高原高寒适应性可分为两个一级指标,12个二级指标,其中高原适应性评价指标的权重为0.7983,高寒适应性的权重指标为0.2135。某直升机高原高寒适应性模糊综合评价值为0.7692,适应性综合评价为较好。结论高原、高寒地区特殊的自然环境、地形地貌、气候条件等都会对航空装备的试验和使用产生很大的影响,航空装备乃至武器装备环境适应性试验的重要性与日俱增,运用模糊综合评价方法能够有效地进行直升机航电系统高原高寒环境适应性评价,提高试验效率。 相似文献
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