Effects of different heat treatment temperatures on properties of Chinese calcined flint clay based plastic refractories were investigated using Chinese calcined flint clay as starting material, aluminum sulfate and f...Effects of different heat treatment temperatures on properties of Chinese calcined flint clay based plastic refractories were investigated using Chinese calcined flint clay as starting material, aluminum sulfate and fireclay as binding system. The results showed that with temperature rising, Chinese calcined flint clay based plastic refractories shrinked firstly and then expanded. The modulus of rupture （MOR） and the cold crushing strength （CCS） inereased firstly and then decreased from 110 ℃ to 600 ℃ , then increased obviously. Thermal expansion coefficient increased from 110 ℃ to 760 ℃, decreased from 760 ℃ to 1 300 ℃ , and increased from 1 300 ℃ to1500 ℃.展开更多
Lead contamination in the City of Flint, MI has been well documented over the past two years, with lead levels above the EPA Action Level until summer 2016. This resulted from an ill-fated decision to switch from Detr...Lead contamination in the City of Flint, MI has been well documented over the past two years, with lead levels above the EPA Action Level until summer 2016. This resulted from an ill-fated decision to switch from Detroit water（Lake Huron） with corrosion control, to Flint River water without corrosion control. Although lead levels are now closer to normal,reports of skin rashes have sparked questions surrounding tap water in some Flint homes.This study investigated the presence of contaminants, including disinfection by-products（DBPs）, in the hot tap water used for showering in the homes of residents in Flint. Extensive quantitative analysis of 61 regulated and priority unregulated DBPs was conducted in Flint hot and cold tap water, along with the analysis of 50 volatile organic compounds and a nontarget comprehensive, broadscreen analysis, to identify a possible source for the reported skin rashes. For comparison, chlorinated hot and cold waters from three other cities were also sampled, including Detroit, which also uses Lake Huron as its source water.Results showed that hot water samples generally contained elevated levels of regulated and priority unregulated DBPs compared to cold water samples, but trihalomethanes were still within regulatory limits. Overall, hot shower water from Flint was similar to waters sampled from the three other cities and did not have unusually high levels of DBPs or other organic chemicals that could be responsible for the skin rashes observed by residents. It is possible that an inorganic chemical or microbial contaminant may be responsible.展开更多
以往的教学评价方式已经难以满足现代化教学中改善师生关系的需求,各类教学分析系统被广泛应用于课堂师生关系的研究中。为了更专业地分析第二语言教学中的师生互动情况,本研究运用Flint互动分析系统(For-eign Language interaction sys...以往的教学评价方式已经难以满足现代化教学中改善师生关系的需求,各类教学分析系统被广泛应用于课堂师生关系的研究中。为了更专业地分析第二语言教学中的师生互动情况,本研究运用Flint互动分析系统(For-eign Language interaction system),以北京语言大学汉语教学示范课为研究对象,精准采集截取两节刘希明老师的综合课语法教学视频进行编码,矩阵量化分析,科学客观地评估了对外汉语教学示范课的师生互动效果,并针对教学过程中存在的问题提出了切实可行的教学建议,以在对外汉语教学中建立良好融洽的师生关系,达到最佳互动效果。展开更多
文摘Effects of different heat treatment temperatures on properties of Chinese calcined flint clay based plastic refractories were investigated using Chinese calcined flint clay as starting material, aluminum sulfate and fireclay as binding system. The results showed that with temperature rising, Chinese calcined flint clay based plastic refractories shrinked firstly and then expanded. The modulus of rupture （MOR） and the cold crushing strength （CCS） inereased firstly and then decreased from 110 ℃ to 600 ℃ , then increased obviously. Thermal expansion coefficient increased from 110 ℃ to 760 ℃, decreased from 760 ℃ to 1 300 ℃ , and increased from 1 300 ℃ to1500 ℃.
基金funding from the U.S.Environmental Protection Agency, Meghan Franco for assistance with XAD resin extractions, Shealy Environmental, Inc.for VOC analyses
文摘Lead contamination in the City of Flint, MI has been well documented over the past two years, with lead levels above the EPA Action Level until summer 2016. This resulted from an ill-fated decision to switch from Detroit water（Lake Huron） with corrosion control, to Flint River water without corrosion control. Although lead levels are now closer to normal,reports of skin rashes have sparked questions surrounding tap water in some Flint homes.This study investigated the presence of contaminants, including disinfection by-products（DBPs）, in the hot tap water used for showering in the homes of residents in Flint. Extensive quantitative analysis of 61 regulated and priority unregulated DBPs was conducted in Flint hot and cold tap water, along with the analysis of 50 volatile organic compounds and a nontarget comprehensive, broadscreen analysis, to identify a possible source for the reported skin rashes. For comparison, chlorinated hot and cold waters from three other cities were also sampled, including Detroit, which also uses Lake Huron as its source water.Results showed that hot water samples generally contained elevated levels of regulated and priority unregulated DBPs compared to cold water samples, but trihalomethanes were still within regulatory limits. Overall, hot shower water from Flint was similar to waters sampled from the three other cities and did not have unusually high levels of DBPs or other organic chemicals that could be responsible for the skin rashes observed by residents. It is possible that an inorganic chemical or microbial contaminant may be responsible.
文摘以往的教学评价方式已经难以满足现代化教学中改善师生关系的需求,各类教学分析系统被广泛应用于课堂师生关系的研究中。为了更专业地分析第二语言教学中的师生互动情况,本研究运用Flint互动分析系统(For-eign Language interaction system),以北京语言大学汉语教学示范课为研究对象,精准采集截取两节刘希明老师的综合课语法教学视频进行编码,矩阵量化分析,科学客观地评估了对外汉语教学示范课的师生互动效果,并针对教学过程中存在的问题提出了切实可行的教学建议,以在对外汉语教学中建立良好融洽的师生关系,达到最佳互动效果。
