Effect of Water Washing Pre-treatment on the Properties of Glass-ceramics from Incinerator Fly Ash Using Electronic Arc Furnace

Production of glass-ceramics by sintering the molten slag obtained from electric arc furnace treatment of fly ash was investigated. The effect of washing pretreatment prior to melting the fly ash on the microstructure and properties of the glass-ceramics was examined. The results show that washing pretreatment of fly ash can decrease alkali metal chloride and increase network former in fly ash, which results in the increase of peak crystallization temperature of parent glass and strengthening of properties of bending strength and chemical stability of the glass-ceramics. The optimal heat treatment temperature for parent glass of washed fly ash is 1 173 K, at which the crystalline phase of glass-ceramics is composed of gelignite （Ca2A12SiO7） and akermanite （Ca2MgSi207）. Glass-ceramics produced at optimal heat treatment temperature are excellent in term of the physical and chemical properties and leaching characteristics, indicating attractive potential as substitute of nature materials.

两种医疗废物应急协同处置技术的生命周期评价

新冠疫情暴发导致医疗废物数量激增,疫情严重地区的医疗废物产生量远超其已有处置能力,其处置成为阻止疫情蔓延的关键环节。对医疗废物分别与危险废物和生活垃圾协同焚烧两种应急处置技术的特点、环境风险及技术适应性进行比较,并通过生命周期评价方法量化比较两种技术的环境影响和关键因素。结果表明:与生活垃圾协同焚烧技术由于发电而具有显著的环境效益;与危险废物协同焚烧,可有效避免二英类物质二次合成,但该技术因能耗高而对环境影响大。对后者的情景优化表明能源回收效率提高63.6%、节能减排指标降低了21.9%。研究结果可为医疗废物应急管理和可持续发展提供参考。

编程学习中学生行为分析与结果预测

通过收集RoboMise这一自适应编程学习系统中学生的行为数据,应用统计分析方法进行学习行为分析;基于学习行为数据,利用机器学习方法,对学生解决任务的结果进行预测。研究结果表明:可以根据学习行为对学习结果作出预测,随机森林算法的综合预测效果最优。